WorldWideScience

Sample records for mode-of-action taxonomic distribution

  1. Taxonomic Challenges and Distribution of Gracilarioid Algae ...

    African Journals Online (AJOL)

    This paper reviews the taxonomical literature of the gracilarioid algae from Tanzania, and provides information about their ecology and distribution based on an intensive regime of local collection. Its aim was to provide names, even if on a preliminary basis, for local gracilarioid taxa. Our revision shows that species ...

  2. Comparative toxicity of 20 herbicides to 5 periphytic algae and the relationship with mode of action.

    Science.gov (United States)

    Nagai, Takashi; Taya, Kiyoshi; Yoda, Ikuko

    2016-02-01

    The authors used 5 species of periphytic algae to conduct toxicity assays of 20 herbicides. The 5 tested species represent riverine primary producers most likely to be affected by herbicides. A fluorescence microplate toxicity assay was used as an efficient and economical high-throughput assay. Toxicity characteristics were analyzed, focusing on their relationship to herbicide mode of action. The relative differences between 50% and 10% effect concentrations depended on herbicide mode of action, rather than tested species. Moreover, a clear relationship between sensitive species and herbicide mode of action was also observed. Green alga was most sensitive to herbicides of 2 mode of action groups: inhibitors of protoporphyrinogen oxidase and very long-chain fatty acid synthesis. Diatoms were most sensitive to herbicides of 1 mode of action group: 4-hydroxyphenyl-pyruvate-dioxygenase inhibitors. Cyanobacterium was most sensitive to herbicides of 1 mode of action group: inhibitors of acetolactate synthase. The species sensitivity distribution based on obtained data was also analyzed. The slopes of the species sensitivity distribution significantly differed among modes of action, suggesting that difference in species sensitivity is specific to the mode of action. In particular, differences in species sensitivity were markedly large for inhibitors of acetolactate synthase, protoporphyrinogen oxidase, and very long-chain fatty acid synthesis. The results clearly showed that a single algal species cannot represent the sensitivity of an algal assemblage. Therefore, multispecies algal toxicity data are essential for substances with specific modes of action. © 2015 SETAC.

  3. Seasonality, distribution and taxonomic status of avian ...

    African Journals Online (AJOL)

    Description of a new species is based upon morphology of gametocyte development in the peripheral blood of the avian host. This does not distinguish between morphologically identical gametocytes from different avian host families, nor is species or family level a valid taxonomic character. Thus, Haemoproteus and ...

  4. Elaiophores: their taxonomic distribution, morphology and functions

    OpenAIRE

    Possobom, Clivia Carolina Fiorilo; Machado, Silvia Rodrigues

    2017-01-01

    ABSTRACT Elaiophores are floral glands that secrete non-volatile oils as a reward for their pollinators. Their secretions mediate a specialized interaction between oil-producing plants and a few species of oil-collecting bees - Apidae and Melittidae. The present review focuses on the morphological and functional aspects of these secretory structures. We also provide information on their chemistry and pollination ecology. Our survey is organized taxonomically among the plant families for which...

  5. Elaiophores: their taxonomic distribution, morphology and functions

    Directory of Open Access Journals (Sweden)

    Clivia Carolina Fiorilo Possobom

    Full Text Available ABSTRACT Elaiophores are floral glands that secrete non-volatile oils as a reward for their pollinators. Their secretions mediate a specialized interaction between oil-producing plants and a few species of oil-collecting bees - Apidae and Melittidae. The present review focuses on the morphological and functional aspects of these secretory structures. We also provide information on their chemistry and pollination ecology. Our survey is organized taxonomically among the plant families for which elaiophore occurrence has been confirmed -for the monocots, Iridaceae and Orchidaceae, and for the eudicots, Calceolariaceae, Cucurbitaceae, Krameriaceae, Malpighiaceae, Plantaginaceae, Primulaceae, Scrophulariaceae, Solanaceae and Stilbaceae. Most oil flowers are zygomorphic, bisexual, nectarless and present their elaiophores on the protective whorls or on the androecium. Trichomal elaiophores are reported in all of these families except Krameriaceae and Malpighiaceae, and they vary in the density and morphology of the trichomes. Epithelial elaiophores occur in some monocot representatives and in Krameriaceae and Malpighiaceae, and are similar among species. An intermediate type of elaiophore is reported in some species of Orchidaceae. Regardless of elaiophore type, these glands have similar subcellular features and secretion-release mechanisms. Finally, we note the dearth of information on elaiophore ultrastructure and functioning for several plant families.

  6. Kyleo ® - mode of action under examination

    Directory of Open Access Journals (Sweden)

    Heibertshausen, Dagmar

    2014-02-01

    Full Text Available Kyleo® with two known active substances (ai is an innovative, modern herbicide for resistance management. Kyleo® contains 160 g/l 2,4-D and 240 g/l glyphosate. With an application rate of 5,0 l/ha, it shows a far better, faster effect on weeds such as field horsetail (Equisetum arvense, volunteer oilseed rape (Brassica napus and couch grass (Agropyron repens compared to a tank mix or the reference products (RP. This is explained by an unique new formulation technology that for the first time combines 2,4-D as acid and glyphosate as MIPA salt together with FHS. The new form of 2,4-D is lipophilic with better leaf absorption and greater photolytic degradation in the upper layers of soil. Tests with radioactive marked substances have verified the systemic properties of both ai compared to RP. The displacement of 2,4-D into the plant roots was demonstrated 48 h after application (hpt. 98% glyphosate absorption was observed in rape and couch grass – 10% (rape respectively 25% (couch grass greater than with RP. Higher absorption of the ai is characterised by a swifter effect, with stronger, visible symptoms after 24 h in rape and 96 h in couch grass. The rainfastness of Kyleo® was tested in greenhouse (GH trials with rape. Comparability of the test objects was simulated with a uniform glyphosate quantity of 360 g/ha and 10 l/m² simulated precipitation. 24% improved effect compared to RP was verified for 1 hpt rainfall, while 4% improved effect was recorded for rain simulation after 6 hpt. GH trials with wheat and a comparable glyphosate application quantity of 290 g/ha revealed differences of 23% and 22% compared to RP for rain simulation of 1 hpt and 6 hpt. Kyleo® stands out with a swift effect and better rainfastness. The results presented here prove a systemic mode of action, good rainfastness and swift effect of Kyleo.

  7. Floristic composition and taxonomic distribution of plants in the ...

    African Journals Online (AJOL)

    Floristic composition and taxonomic distribution of plants in the dryland of Northwestern Nigeria. ... Analysis of abundance and rarity of species reveals that 10% and 90% of the encountered species were abundant and rare respectively in the study area. These finding poses serious ecological concerns in the study area, ...

  8. Adjuvanted vaccines: Aspects of immunosafety and modes of action

    NARCIS (Netherlands)

    van Aalst, S.

    2017-01-01

    New developments in vaccine design shift towards safe, though sometimes less immunogenic, subunit and synthetic antigens. Therefore, the majority of current vaccines require adjuvants to increase immunogenicity. Most adjuvants available were developed empirically and their mode of action is only

  9. Mode of action of Buddleja cordata verbascoside against Staphylococcus aureus.

    Science.gov (United States)

    Avila, J G; de Liverant, J G; Martínez, A; Martínez, G; Muñoz, J L; Arciniegas, A; Romo de Vivar, A

    1999-07-01

    We evaluate the mode of action of verbascoside obtained from Buddleja cordata against Staphylococcus aureus by killing kinetics and incorporation of precursors methods. Verbascoside induced lethal effect on S. aureus, by affecting protein synthesis and inhibiting leucine incorporation.

  10. Effect and mode of action of some systemic nematicides

    NARCIS (Netherlands)

    Bunt, J.A.

    1975-01-01

    In this study, nematicidal effects, mode of action and specific characters of some systemic nematicides were studied, in search of substitutes for the widely used soil fumigants that require high dosages. The thesis comprises:

    - a review of literature,
    - development of

  11. Untargeted Metabolomics To Ascertain Antibiotic Modes of Action

    Science.gov (United States)

    Vincent, Isabel M.; Ehmann, David E.; Mills, Scott D.; Perros, Manos

    2016-01-01

    Deciphering the mode of action (MOA) of new antibiotics discovered through phenotypic screening is of increasing importance. Metabolomics offers a potentially rapid and cost-effective means of identifying modes of action of drugs whose effects are mediated through changes in metabolism. Metabolomics techniques also collect data on off-target effects and drug modifications. Here, we present data from an untargeted liquid chromatography-mass spectrometry approach to identify the modes of action of eight compounds: 1-[3-fluoro-4-(5-methyl-2,4-dioxo-pyrimidin-1-yl)phenyl]-3-[2-(trifluoromethyl)phenyl]urea (AZ1), 2-(cyclobutylmethoxy)-5′-deoxyadenosine, triclosan, fosmidomycin, CHIR-090, carbonyl cyanide m-chlorophenylhydrazone (CCCP), 5-chloro-2-(methylsulfonyl)-N-(1,3-thiazol-2-yl)-4-pyrimidinecarboxamide (AZ7), and ceftazidime. Data analysts were blind to the compound identities but managed to identify the target as thymidylate kinase for AZ1, isoprenoid biosynthesis for fosmidomycin, acyl-transferase for CHIR-090, and DNA metabolism for 2-(cyclobutylmethoxy)-5′-deoxyadenosine. Changes to cell wall metabolites were seen in ceftazidime treatments, although other changes, presumably relating to off-target effects, dominated spectral outputs in the untargeted approach. Drugs which do not work through metabolic pathways, such as the proton carrier CCCP, have no discernible impact on the metabolome. The untargeted metabolomics approach also revealed modifications to two compounds, namely, fosmidomycin and AZ7. An untreated control was also analyzed, and changes to the metabolome were seen over 4 h, highlighting the necessity for careful controls in these types of studies. Metabolomics is a useful tool in the analysis of drug modes of action and can complement other technologies already in use. PMID:26833150

  12. Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles

    Science.gov (United States)

    Kalinin, Vladimir I.; Ivanchina, Natalia V.; Krasokhin, Vladimir B.; Makarieva, Tatyana N.; Stonik, Valentin A.

    2012-01-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed. PMID:23015769

  13. Partial migration in fishes: definitions, methodologies and taxonomic distribution

    DEFF Research Database (Denmark)

    Chapman, B B; Skov, C; Hulthén, K

    2012-01-01

    Partial migration, where populations are composed of both migratory and resident individuals, is extremely widespread across the animal kingdom. Researchers studying fish movements have long recognized that many fishes are partial migrants, however, no detailed taxonomic review has ever been...

  14. Taxonomic status and distribution of the South African lizard ...

    African Journals Online (AJOL)

    The taxonomic status of the poorly known South African gerrhosaurid Tetradactylus breyeri, described by Roux in 1907 on the basis of a single specimen from the Transvaal, was investigated. The holotype and 14 other preserved specimens were examined and are described in detail. Prior to this study, only six specimens ...

  15. Modes of Action of Herbal Medicines and Plant Secondary Metabolites

    Directory of Open Access Journals (Sweden)

    Michael Wink

    2015-09-01

    Full Text Available Plants produce a wide diversity of secondary metabolites (SM which serve them as defense compounds against herbivores, and other plants and microbes, but also as signal compounds. In general, SM exhibit a wide array of biological and pharmacological properties. Because of this, some plants or products isolated from them have been and are still used to treat infections, health disorders or diseases. This review provides evidence that many SM have a broad spectrum of bioactivities. They often interact with the main targets in cells, such as proteins, biomembranes or nucleic acids. Whereas some SM appear to have been optimized on a few molecular targets, such as alkaloids on receptors of neurotransmitters, others (such as phenolics and terpenoids are less specific and attack a multitude of proteins by building hydrogen, hydrophobic and ionic bonds, thus modulating their 3D structures and in consequence their bioactivities. The main modes of action are described for the major groups of common plant secondary metabolites. The multitarget activities of many SM can explain the medical application of complex extracts from medicinal plants for more health disorders which involve several targets. Herbal medicine is not a placebo medicine but a rational medicine, and for several of them clinical trials have shown efficacy.

  16. On the antifungal mode of action of tridemorph

    NARCIS (Netherlands)

    Kerkenaar, A.; Barug, D.; Kaars Sijpesteijn, A.

    1979-01-01

    Tridemorph (2,6-dimethyl-N-tridecylmorpholine) was active against representative of nearly all taxonomic groups of fungi; gram-positive bacteria were also sensitive although gram-negative were not. Tridemorph, 3–10 μg/ml, inhibited the multiplication of sporidia of Ustilago maydis more strongly than

  17. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Science.gov (United States)

    Waldbusser, George G; Hales, Burke; Langdon, Chris J; Haley, Brian A; Schrader, Paul; Brunner, Elizabeth L; Gray, Matthew W; Miller, Cale A; Gimenez, Iria; Hutchinson, Greg

    2015-01-01

    Ocean acidification (OA) is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4) with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material affected only by

  18. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Directory of Open Access Journals (Sweden)

    George G Waldbusser

    Full Text Available Ocean acidification (OA is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4 with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material

  19. Life cycle responses of the midge Chironomus riparius to compounds with different modes of action

    NARCIS (Netherlands)

    Marinkovic, M.; Verweij, R.A.; Nummerdor, G.A.; Jonker, M.J.; Kraak, M.H.S.; Admiraal, W.

    2011-01-01

    Compounds with different modes of action may affect life cycles of biota differently. The aim of the present study was therefore to investigate the impact of four chemicals with different modes of action, including the essential metal copper, the nonessential metal cadmium, the organometal

  20. Effects of insecticides with different modes of action in the control of ...

    African Journals Online (AJOL)

    The aim of the study was to evaluate the use of insecticides with different modes of action on banana borer weevil. Insecticides with different modes of action were administered to banana weevils (Cosmopolites sordidus) in small containers (1 litre by volume) with perforated lids and monitored in the laboratory at room ...

  1. The taxonomic composition, distribution and abundance of the ...

    African Journals Online (AJOL)

    The study determined the abundance and distribution of phytoplankton flora of an impoundment in the Agricultural Teaching and Research Farm of ObafemiAwolowo University (O.A.U), Ile-Ife, Osun State, Nigeria. The study was carried out over an annual cycle from September 2006- August 2007, Phytoplankton and water ...

  2. Response to Comment on “Mode of Action (MOA) Assignment Classifications for Ecotoxicology: An Evaluation of Approaches”

    Science.gov (United States)

    This letter to the editor that does not have an abstract. It explains mode of action in aquatic toxicology, and rebuts comments about our mode of action classification caused by confusion of the commenter.

  3. Linking toxicant molecular and physiological mode of action in Caenorhabditis elegans.

    NARCIS (Netherlands)

    Swain, S.; Wren, J.; Sturzenbaum, S.R.; Kille, P.; Morgan, A.J.; Jager, T.; Jonker, M.J.; Hankard, P.K.; Scendsen, C.; Owen, J.; Hedley, B.A.; Blaxter, M.; Spurgeon, D.

    2010-01-01

    Background: Physiologically based modelling using DEBtox (dynamic energy budget in toxicology) and transcriptional profiling were used in Caenorhabditis elegans to identify how physiological modes of action, as indicated by effects on system level resource allocation were associated with changes in

  4. Linking toxicant physiological mode of action with induced gene expression changes in Caenorhabditis elegans

    NARCIS (Netherlands)

    Swain, S.; Wren, J.F.; Stürzenbaum, S.R.; Kille, P.; Morgan, A.J.; Jager, T.; Jonker, M.J.; Hankard, P.K.; Svendsen, C.; Owen, J.; Hedley, B.A.; Blaxter, M.; Spurgeon, D.J.

    2010-01-01

    Background: Physiologically based modelling using DEBtox (dynamic energy budget in toxicology) and transcriptional profiling were used in Caenorhabditis elegans to identify how physiological modes of action, as indicated by effects on system level resource allocation were associated with changes in

  5. Mode of Action for Reproductive and Hepatic Toxicity Inferred from a Genomic Study of Triazole Antifungals

    Science.gov (United States)

    The mode of action for the reproductive toxicity of triazole antifungals have been previously characterized by an observed increased in serum testosterone, hepatotoxicity, and reduced insemination and fertility indices. In order to refine our mechanistic understanding of these m...

  6. Counselling and knowledge about contraceptive mode of action among married women; a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Ciğerli Özlem

    2006-08-01

    Full Text Available Abstract Background Family planning counselling which covers knowledge transfer about contraceptive mode of action, by enabling informed choice, improves compliance to and efficiency of contraceptive methods. The objective of this study was to investigate associations between family planning counselling, counsellor and correct knowledge about mode of action of modern contraceptive methods among married women. Methods For this cross-sectional study, stratified (according to current modern contraceptive method in use random sampling was performed from the registries of two primary health care centres. Main outcomes were; prevalence of family planning counselling, professional background of the counsellor and correct knowledge about mode of action. A semi-structured questionnaire developed by the researchers was applied via face-to-face interview. The answers about mode of action were categorized as correct vs. incorrect by consensus rating. Results Prevalence of counselling and correct knowledge about mode of action was 49.0% and 39.3%, respectively. Higher educated women were significantly more likely to know the mode of action (p p = 0.79. Non-barrier method users were less educated (p = 0.001, more often counselled (60.8% vs. 8.0% and less knowledgeable (p p = 0.021 than counselled condom users. Conclusion The beneficial effect of counselling on knowledge about mode of action of the more complicated, medical (non-barrier contraceptive methods suggests that the use of family planning counselling services in primary health care should be promoted; furthermore, counselling strategies and content should be re-structured for better efficacy.

  7. The occurrence and taxonomic distribution of the anthrones aloin, aloinoside and microdontin in Aloe.

    Science.gov (United States)

    Viljoen; Wyk; Newton

    2001-01-01

    A chemotaxonomic survey of 380 species of Aloe indicated the presence of the anthrone isomers aloin A and B together with the aloinoside isomers and microdontin A and B in 36 (10%) species of Aloe. This group, referred to as the microdontin chemotype, is thus characterised by a combination of exudate compounds and not merely a single phytochemical marker, implying taxonomic significance of leaf exudate compounds. The 36 representatives of the group occupy disparate taxonomic positions in the largely artificial hierarchy of the present classification system. Although many of the species have previously been considered as related (based on macromorphology only), a large number of species have not been associated with one another before. The chemical profiles and leaf exudate compositions of the species are presented, followed by a brief summary of the morphological diversity. Whilst conceding the possibility of convergent evolution, the geographical distribution of the species and thoughts on possible relationships between the taxa are discussed.

  8. Mode of Action (MOA) Assignment Classifications for Ecotoxicology: Evaluation of Available Methods

    Science.gov (United States)

    There are various structure-based classification schemes to categorize chemicals based on mode of action (MOA) which have been applied for both eco and human toxicology. With increasing calls to assess 1000s of chemicals, some of which have little available information other tha...

  9. A Critical Review of Mode of Action (MOA) Assignment Classifications for Ecotoxicology

    Science.gov (United States)

    There are various structure-based classification schemes to categorize chemicals based on mode of action (MOA) which have been applied for both eco and human health toxicology. With increasing calls to assess thousands of chemicals, some of which have little available informatio...

  10. Innovative mode of action based in vitro assays for detection of marine neurotoxins

    NARCIS (Netherlands)

    Nicolas, J.A.Y.

    2015-01-01

    Innovative mode of action based in vitro assays for detection of marine neurotoxins

    J. Nicolas, P.J.M. Hendriksen, T.F.H. Bovee, I.M.C.M. Rietjens

    Marine biotoxins are naturally occurring compounds produced by particular phytoplankton species. These toxins often accumulate in

  11. SOME INSIGHTS INTO THE MODE OF ACTION OF BUTADIENE BY EXAMINING THE GENOTOXICITY OF ITS METABOLITES

    Science.gov (United States)

    1,3-Butadiene (BTD) is an important commodity chemical and air pollutant that has been shown to be a potent carcinogen in mice, and to a lesser extent, a carcinogen in rats. To better assess butadiene's carcinogenic risk to humans, it is important to understand its mode of action...

  12. Application of mass spectrometric techniques to delineate the modes-of-action of anticancer metallodrugs

    NARCIS (Netherlands)

    Hartinger, Christian G.; Groessl, Michael; Meier, Samuel M.; Casini, Angela; Dyson, Paul J.

    2013-01-01

    Mass spectrometry (MS) has emerged as an important tool for studying anticancer metallodrugs in complex biological samples and for characterising their interactions with biomolecules and potential targets on a molecular level. The exact modes-of-action of these coordination compounds and especially

  13. Triclosan Decreases Rat Thyroxine: Mode-of-Action, Developmental Susceptibility and Human Relevance

    Science.gov (United States)

    Triclosan (TCS) decreases serum thyroxine (T4) in the rat. In vivo and in vitro approaches were used to address three uncertainties: by what mode-of-action (MOA) does TCS decrease T4; does TCS decrease T4 developmentally; and, are effects observed in rats relevant to humans? To t...

  14. An evaluation of the mode of action framework for mutagenic carcinogens: Chromium (VI): SOT.

    Science.gov (United States)

    In response to the 2005 revised U.S Environmental Protection Agency’s (EPA) Cancer Guidelines, a strategy is being developed to determine whether a carcinogen operates through a mutagenic mode of action (MOA). This information is necessary for EPA to decide whether age-dependent ...

  15. An evaluation of the mode of action framework for mutagenic carcinogens: chromium (VI)

    Science.gov (United States)

    In response to the 2005 revised U.S Environmental Protection Agency’s (EPA) Cancer Guidelines, a strategy is being developed to determine whether a carcinogen operates through a mutagenic mode of action (MOA). This information is necessary for EPA to decide whether age-dependent ...

  16. Mode of Action Profiles for Pesticide Compounds with Rodent Liver Tumor Outcomes

    Science.gov (United States)

    Mode of action (MOA) provides a central framework for assessing human relevance of adverse health outcomes observed in nonclinical safety studies. The goal of this study was to characterize MOA profiles for known rodent liver tumorigens identified from a database of pesticides as...

  17. Mode of action of the phenylpyrrole fungicide fenpiclonil in Fusarium sulphureum

    NARCIS (Netherlands)

    Jespers, A.B.K.

    1994-01-01

    In the last few decades, plant disease control has become heavily dependent on fungicides. Most modem fungicides were discovered by random synthesis and empirical optimization of lead structures. In general, these fungicides have specific modes of action and meet modem enviromnental

  18. How benthic diatoms within natural communities respond to eight common herbicides with different modes of action.

    Science.gov (United States)

    Wood, Rebecca J; Mitrovic, Simon M; Lim, Richard P; Kefford, Ben J

    2016-07-01

    Herbicides are common pollutants of rivers in agricultural regions. These contaminants include various types of chemicals with different modes of toxic action. Herbicides can have toxic effects on freshwater benthic diatoms, the base of the aquatic food web. We examined the effects of (non-mixture) herbicide exposure to the health of diatoms for eight common herbicides with three different modes of action; the photosystem II (PSII) inhibitors: atrazine, simazine, hexazinone, tebuthiuron and diuron; two auxinic herbicides: MCPA and 2,4-D; and the EPSP synthase inhibitor: glyphosate. Benthic diatoms within riverine communities were exposed to each herbicide in rapid toxicity tests at concentrations of 50, 200 and 500μgL(-1). The most sensitive taxa were Gomphonema spp. and Encyonema gracilis. Navicula cryptotenella was the most tolerant to herbicide exposure. There was no significant effect of the different herbicide modes of action at the community level. Herbicide mode of action did not alter which taxa were most sensitive within the community and sensitivity rankings of the dominant diatom taxa were similar for each of the eight herbicides. The consistency of the results between herbicides suggests that freshwater benthic diatoms may be suitable in situ indicators for detecting the toxicity of herbicides with differing modes of action. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Exposure assessment of the cumulative intake of pesticides with dissimilar mode of action

    DEFF Research Database (Denmark)

    Jensen, Bodil Hamborg; Petersen, Annette; Christiansen, Sofie

    . In this study the effects of combined exposure from four endocrine disrupting pesticides have been investigated (procymidone, mancozeb, tebuconazole, and prochloraz). The four pesticides have dissimilar mode of actions. On the background of the potency for each pesticide to a given effect, a relative potency...

  20. Mixture toxicity of three toxicants with similar and dissimilar modes of action to Daphnia magna

    DEFF Research Database (Denmark)

    Syberg, K.; Engell-Kofoed, Anders Elleby; Pedersen, H.

    2008-01-01

    the predictive capability of the models, we conducted Daphnia magna 48 h immobilization experiments with three toxicants with known modes of action (dimethoate, pirimicarb and linear alkyl benzene sulfonate) singly, and in binary and ternary mixtures. Our results indicate that CA and IA predict binary mixtures...

  1. Macromolecule biosynthesis assay and fluorescence spectroscopy methods to explore antimicrobial peptide mode(s) of action

    DEFF Research Database (Denmark)

    Jana, Bimal; Baker, Kristin Renee; Guardabassi, Luca

    2017-01-01

    the biosynthesis rate of macromolecules (e.g., DNA, RNA, protein, and cell wall) and the cytoplasmic membrane proton motive force (PMF) energy can help to unravel the diverse modes of action of AMPs. Here, we present an overview of macromolecule biosynthesis rate measurement and fluorescence spectroscopy methods...

  2. Evolved pesticide tolerance in amphibians: Predicting mechanisms based on pesticide novelty and mode of action

    International Nuclear Information System (INIS)

    Hua, Jessica; Jones, Devin K.; Mattes, Brian M.; Cothran, Rickey D.; Relyea, Rick A.; Hoverman, Jason T.

    2015-01-01

    We examined 10 wood frog populations distributed along an agricultural gradient for their tolerance to six pesticides (carbaryl, malathion, cypermethrin, permethrin, imidacloprid, and thiamethoxam) that differed in date of first registration (pesticide novelty) and mode-of-action (MOA). Our goals were to assess whether: 1) tolerance was correlated with distance to agriculture for each pesticide, 2) pesticide novelty predicted the likelihood of evolved tolerance, and 3) populations display cross-tolerance between pesticides that share and differ in MOA. Wood frog populations located close to agriculture were more tolerant to carbaryl and malathion than populations far from agriculture. Moreover, the strength of the relationship between distance to agriculture and tolerance was stronger for older pesticides compared to newer pesticides. Finally, we found evidence for cross-tolerance between carbaryl and malathion (two pesticides that share MOA). This study provides one of the most comprehensive approaches for understanding patterns of evolved tolerance in non-pest species. - Highlights: • We explored patterns of tolerance to six insecticides across 10 wood frog populations. • We found evidence that wood frogs have evolved tolerance to carbaryl and malathion. • The likelihood of evolved tolerance was stronger for older compared to newer pesticides. • We found evidence for cross-tolerance between carbaryl and malathion. • This is one of the most comprehensive approaches studying evolved tolerance in a non-pest species. - Using 10 wood frog populations, we detected evidence for evolved tolerance, found that the evolved tolerance depends on insecticide novelty, and found evidence for cross-tolerance.

  3. Studies on the Mode of Action of the Antifungal Hexapeptide PAF26

    OpenAIRE

    Muñoz, Alberto; López-García, Belén; Marcos, Jose F.

    2006-01-01

    The small antimicrobial peptide PAF26 (Ac-RKKWFW-NH2) has been identified by a combinatorial approach and shows preferential activity toward filamentous fungi. In this work, we investigated the mode of action and inhibitory effects of PAF26 on the fungus Penicillium digitatum. The dye Sytox Green was used to demonstrate that PAF26 induced cell permeation. However, microscopic observations showed that sub-MIC concentrations of PAF26 produced both alterations of hyphal morphology (such as alter...

  4. Toxicity of 13 different antibiotics towards freshwater green algae Pseudokirchneriella subcapitata and their modes of action.

    Science.gov (United States)

    Fu, Ling; Huang, Tao; Wang, Shuo; Wang, Xiaohong; Su, Limin; Li, Chao; Zhao, Yuanhui

    2017-02-01

    Although modes of action (MOAs) play a key role in the understanding of the toxic mechanism of chemicals, the MOAs have not been investigated for antibiotics to green algae. This paper is to discriminate excess toxicity from baseline level and investigate the MOAs of 13 different antibiotics to algae by using the determined toxicity values. Comparison of the toxicities shows that the inhibitors of protein synthesis to bacteria, such as azithromycin, doxycycline, florfenicol and oxytetracycline, exhibit significantly toxic effects to algae. On the other hand, the cell wall synthesis inhibitors, such as cefotaxime and amoxicillin, show relatively low toxic effects to the algae. The concentrations determined by HPLC indicate that quinocetone and amoxicillin can be easily photodegraded or hydrolyzed during the toxic tests. The toxic effects of quinocetone and amoxicillin to the algae are attributed to not only their parent compounds, but also their metabolites. Investigation on the mode of action shows that, except rifampicin, all the tested antibiotics exhibit excess toxicity to Pseudokirchneriella subcapitata (P. subcapitata). These antibiotics can be identified as reactive modes of action to the algae. They act as electrophilic mechanism of action to P. subcapitata. These results are valuable for the understanding of the toxic mechanism to algae. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Benthos of the Gorda Ridge axial valley (NE Pacific Ocean): Taxonomic composition and trends in distribution

    Science.gov (United States)

    Carey, A. G.; Stein, D. L.; Rona, P. L.

    Distribution and relative abundance of invertebrate mega-epifauna and benthic fishes were studied in the Gorda Ridge central rift valley off southern Oregon and northern California, USA. Faunal distribution and relative abundance were correlated with location, geological setting, substrate type, and depth. Bottom photographs and videotapes were from 1985-1986 cruises by the US Geological Survey and the US National Oceanic and Atmospheric Administration. Voucher specimens were collected by rock dredge, fish trap, and the Deep Submergence Vehicle (DSV) Sea Cliff. Location rather than substrate appears to have more effect on the overall taxonomic composition of the mega-epifauna in the northern and southern parts of the rift valley. Within each location, substrate type, i.e. soft sediments and rock outcrops, and percentage cover of these substrates appear to influence the existing faunal composition. Characteristic fauna are associated with each substrate type, e.g. crinoids, gorgonians and sponges (Demospongiae) on rocky surfaces. In the southern sediment-filled Escanaba Trough, deposit-feeding organisms, particularly ophiuroids, asteroids and holothuroids, are interspersed with stalked suspension feeders, such as hexactinellid sponges and pennatulids. Epifaunal community structure in the northern and southern sectors differs, even on similar substrate combinations. Except for the ubiquitous macrourids, fish species distributions may be correlated with substrate type. Abundant particulate material in the bottom water layer probably accounts for large concentrations of suspension and detritus feeding epibenthos.

  6. Influence of Taxonomic Relatedness and Chemical Mode of Action in Acute Interspecies Estimation Models for Aquatic species

    Science.gov (United States)

    Ecological risks to aquatic organisms are typically assessed using toxicity data for relatively few species and with limited understanding of relative species sensitivity. We developed a comprehensive set of interspecies correlation estimation (ICE) models for aquatic organisms a...

  7. Revising the taxonomic distribution, origin and evolution of ribosome inactivating protein genes.

    Directory of Open Access Journals (Sweden)

    Walter J Lapadula

    Full Text Available Ribosome inactivating proteins are enzymes that depurinate a specific adenine residue in the alpha-sarcin-ricin loop of the large ribosomal RNA, being ricin and Shiga toxins the most renowned examples. They are widely distributed in plants and their presence has also been confirmed in a few bacterial species. According to this taxonomic distribution, the current model about the origin and evolution of RIP genes postulates that an ancestral RIP domain was originated in flowering plants, and later acquired by some bacteria via horizontal gene transfer. Here, we unequivocally detected the presence of RIP genes in fungi and metazoa. These findings, along with sequence and phylogenetic analyses, led us to propose an alternative, more parsimonious, hypothesis about the origin and evolutionary history of the RIP domain, where several paralogous RIP genes were already present before the three domains of life evolved. This model is in agreement with the current idea of the Last Universal Common Ancestor (LUCA as a complex, genetically redundant organism. Differential loss of paralogous genes in descendants of LUCA, rather than multiple horizontal gene transfer events, could account for the complex pattern of RIP genes across extant species, as it has been observed for other genes.

  8. Identification, expression, and taxonomic distribution of alternative oxidases in non-angiosperm plants.

    Science.gov (United States)

    Neimanis, Karina; Staples, James F; Hüner, Norman P A; McDonald, Allison E

    2013-09-10

    Alternative oxidase (AOX) is a terminal ubiquinol oxidase present in the respiratory chain of all angiosperms investigated to date, but AOX distribution in other members of the Viridiplantae is less clear. We assessed the taxonomic distribution of AOX using bioinformatics. Multiple sequence alignments compared AOX proteins and examined amino acid residues involved in AOX catalytic function and post-translational regulation. Novel AOX sequences were found in both Chlorophytes and Streptophytes and we conclude that AOX is widespread in the Viridiplantae. AOX multigene families are common in non-angiosperm plants and the appearance of AOX1 and AOX2 subtypes pre-dates the divergence of the Coniferophyta and Magnoliophyta. Residues involved in AOX catalytic function are highly conserved between Chlorophytes and Streptophytes, while AOX post-translational regulation likely differs in these two lineages. We demonstrate experimentally that an AOX gene is present in the moss Physcomitrella patens and that the gene is transcribed. Our findings suggest that AOX will likely exert an influence on plant respiration and carbon metabolism in non-angiosperms such as green algae, bryophytes, liverworts, lycopods, ferns, gnetophytes, and gymnosperms and that further research in these systems is required. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Essential oils in food preservation: mode of action, synergies, and interactions with food matrix components

    Directory of Open Access Journals (Sweden)

    Morten eHyldgaard

    2012-01-01

    Full Text Available Essential oils are aromatic and volatile liquids extracted from plants. The chemicals in essential oils are secondary metabolites, which play an important role in plant defence as they often possess antimicrobial properties. The interest in essential oils and their application in food preservation has been amplified in recent years by an increasingly negative consumer perception of synthetic preservatives. Furthermore, food-borne diseases are a growing public health problem worldwide, calling for more effective preservation strategies. The antibacterial properties of essential oils and their constituents have been documented extensively. Pioneering work has also elucidated the mode of action of a few essential oil constituents, but detailed knowledge about most of the compounds' mode of action is still lacking. This knowledge is particularly important to predict their effect on different microorganisms, how they interact with food matrix components, and how they work in combination with other antimicrobial compounds. The main obstacle for using essential oil constituents as food preservatives is that they are most often not potent enough as single components, and they cause negative organoleptic effects when added in sufficient amounts to provide an antimicrobial effect. Exploiting synergies between several compounds has been suggested as a solution to this problem. However, little is known about which interactions lead to synergistic, additive, or antagonistic effects. Such knowledge could contribute to design of new and more potent antimicrobial blends, and to understand the interplay between the constituents of crude essential oils. The purpose of this review is to provide an overview of current knowledge about the antibacterial properties and antibacterial mode of action of essential oils and their constituents, and to identify research avenues that can facilitate implementation of essential oils as natural preservatives in foods.

  10. Linking toxicant physiological mode of action with induced gene expression changes in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Svendsen Claus

    2010-03-01

    Full Text Available Abstract Background Physiologically based modelling using DEBtox (dynamic energy budget in toxicology and transcriptional profiling were used in Caenorhabditis elegans to identify how physiological modes of action, as indicated by effects on system level resource allocation were associated with changes in gene expression following exposure to three toxic chemicals: cadmium, fluoranthene (FA and atrazine (AZ. Results For Cd, the physiological mode of action as indicated by DEBtox model fitting was an effect on energy assimilation from food, suggesting that the transcriptional response to exposure should be dominated by changes in the expression of transcripts associated with energy metabolism and the mitochondria. While evidence for effect on genes associated with energy production were seen, an ontological analysis also indicated an effect of Cd exposure on DNA integrity and transcriptional activity. DEBtox modelling showed an effect of FA on costs for growth and reproduction (i.e. for production of new and differentiated biomass. The microarray analysis supported this effect, showing an effect of FA on protein integrity and turnover that would be expected to have consequences for rates of somatic growth. For AZ, the physiological mode of action predicted by DEBtox was increased cost for maintenance. The transcriptional analysis demonstrated that this increase resulted from effects on DNA integrity as indicated by changes in the expression of genes chromosomal repair. Conclusions Our results have established that outputs from process based models and transcriptomics analyses can help to link mechanisms of action of toxic chemicals with resulting demographic effects. Such complimentary analyses can assist in the categorisation of chemicals for risk assessment purposes.

  11. Biosynthesis of endocannabinoids and their modes of action in neurodegenerative diseases

    DEFF Research Database (Denmark)

    van der Stelt, M.; Veldink, G.A.; Vliegenthart, J.F.G.

    2003-01-01

    with the proteins responsible for their biosynthesis, inactivation and the cannabinoid receptors, these lipids constitute the endocannabinoid system. This system is proposed to be involved in various neurodegenerative diseases such as Parkinson's and Huntington's diseases as well as Multiple Sclerosis. It has been...... demonstrated that the endocannabinoid system can protect neurons against glutamate excitotoxicity and acute neuronal damage in both in vitro and in vivo models. In this paper we review the data concerning the involvement of the endocannabinoid system in neurodegenerative diseases in which neuronal cell death...... may be elicited by excitotoxicity. We focus on the biosynthesis of endocannabinoids and on their modes of action in animal models of these neurodegenerative diseases....

  12. Competitive exclusion as a mode of action of a novel Bacillus cereus aquaculture biological agent

    CSIR Research Space (South Africa)

    Lalloo, R

    2010-01-01

    Full Text Available -109. 17 18 Brunt, J. and Austin, B. (2005) Use of a probiotic to control Latococcosis and streptococcosis in 19 rainbow trout, Oncorhynchus mykiss (Walbaum). J Fish Dis 28, 693-701. 20 21 Chart, H. and Trust, T.J. (1983) Acquisition of iron... controls Aeromonas infection in rainbow trout (Oncorhynchus mykiss, 22 Walbaum). J Appl Microbiol 103, 1699-706. 23 Mode of action B. cereus 18 1 Park, R.Y., Choi, M.H., Sun, H.Y. and Shin, S.H. (2005) Production of catechol-siderophore and 2...

  13. Inhibition of voltage-gated calcium channels as common mode of action for (mixtures of) distinct classes of insecticides

    NARCIS (Netherlands)

    Meijer, Marieke; Dingemans, Milou M L; van den Berg, Martin; Westerink, Remco H S

    Humans are exposed to distinct structural classes of insecticides with different neurotoxic modes of action. Because calcium homeostasis is essential for proper neuronal function and development, we investigated the effects of insecticides from different classes (pyrethroid: (α-)cypermethrin;

  14. Mode of Action of Lactoperoxidase as Related to Its Antimicrobial Activity: A Review

    Directory of Open Access Journals (Sweden)

    F. Bafort

    2014-01-01

    Full Text Available Lactoperoxidase is a member of the family of the mammalian heme peroxidases which have a broad spectrum of activity. Their best known effect is their antimicrobial activity that arouses much interest in in vivo and in vitro applications. In this context, the proper use of lactoperoxidase needs a good understanding of its mode of action, of the factors that favor or limit its activity, and of the features and properties of the active molecules. The first part of this review describes briefly the classification of mammalian peroxidases and their role in the human immune system and in host cell damage. The second part summarizes present knowledge on the mode of action of lactoperoxidase, with special focus on the characteristics to be taken into account for in vitro or in vivo antimicrobial use. The last part looks upon the characteristics of the active molecule produced by lactoperoxidase in the presence of thiocyanate and/or iodide with implication(s on its antimicrobial activity.

  15. Probiotics as beneficial microbes in aquaculture: an update on their multiple modes of action: a review.

    Science.gov (United States)

    Zorriehzahra, Mohammad Jalil; Delshad, Somayeh Torabi; Adel, Milad; Tiwari, Ruchi; Karthik, K; Dhama, Kuldeep; Lazado, Carlo C

    2016-12-01

    Wide and discriminate use of antibiotics has resulted in serious biological and ecological concerns, especially the emergence of antibiotic resistance. Probiotics, known as beneficial microbes, are being proposed as an effective and eco-friendly alternative to antibiotics. They were first applied in aquaculture species more than three decades ago, but considerable attention had been given only in the early 2000s. Probiotics are defined as live or dead, or even a component of the microorganisms that act under different modes of action in conferring beneficial effects to the host or to its environment. Several probiotics have been characterized and applied in fish and a number of them are of host origin. Unlike some disease control alternatives being adapted and proposed in aquaculture where actions are unilateral, the immense potential of probiotics lies on their multiple mechanisms in conferring benefits to the host fish and the rearing environment. The staggering number of probiotics papers in aquaculture highlights the multitude of advantages from these microorganisms and conspicuously position them in the dynamic search for health-promoting alternatives for cultured fish. This paper provides an update on the use of probiotics in finfish aquaculture, particularly focusing on their modes of action. It explores the contemporary understanding of their spatial and nutritional competitiveness, inhibitory metabolites, environmental modification capability, immunomodulatory potential and stress-alleviating mechanism. This timely update affirms the importance of probiotics in fostering sustainable approaches in aquaculture and provides avenues in furthering its research and development.

  16. Acetylcholinesterase in Biofouling Species: Characterization and Mode of Action of Cyanobacteria-Derived Antifouling Agents.

    Science.gov (United States)

    Almeida, Joana R; Freitas, Micaela; Cruz, Susana; Leão, Pedro N; Vasconcelos, Vitor; Cunha, Isabel

    2015-07-24

    Effective and ecofriendly antifouling (AF) compounds have been arising from naturally produced chemicals. The objective of this study is to use cyanobacteria-derived agents to investigate the role of acetylcholinesterase (AChE) activity as an effect and/or mode of action of promising AF compounds, since AChE inhibitors were found to inhibit invertebrate larval settlement. To pursue this objective, in vitro quantification of AChE activity under the effect of several cyanobacterial strain extracts as potential AF agents was performed along with in vivo AF (anti-settlement) screening tests. Pre-characterization of different cholinesterases (ChEs) forms present in selected tissues of important biofouling species was performed to confirm the predominance of AChE, and an in vitro AF test using pure AChE activity was developed. Eighteen cyanobacteria strains were tested as source of potential AF and AChE inhibitor agents. Results showed effectiveness in selecting promising eco-friendly AF agents, allowing the understanding of the AF biochemical mode of action induced by different compounds. This study also highlights the potential of cyanobacteria as source of AF agents towards invertebrate macrofouling species.

  17. Acetylcholinesterase in Biofouling Species: Characterization and Mode of Action of Cyanobacteria-Derived Antifouling Agents

    Directory of Open Access Journals (Sweden)

    Joana R. Almeida

    2015-07-01

    Full Text Available Effective and ecofriendly antifouling (AF compounds have been arising from naturally produced chemicals. The objective of this study is to use cyanobacteria-derived agents to investigate the role of acetylcholinesterase (AChE activity as an effect and/or mode of action of promising AF compounds, since AChE inhibitors were found to inhibit invertebrate larval settlement. To pursue this objective, in vitro quantification of AChE activity under the effect of several cyanobacterial strain extracts as potential AF agents was performed along with in vivo AF (anti-settlement screening tests. Pre-characterization of different cholinesterases (ChEs forms present in selected tissues of important biofouling species was performed to confirm the predominance of AChE, and an in vitro AF test using pure AChE activity was developed. Eighteen cyanobacteria strains were tested as source of potential AF and AChE inhibitor agents. Results showed effectiveness in selecting promising eco-friendly AF agents, allowing the understanding of the AF biochemical mode of action induced by different compounds. This study also highlights the potential of cyanobacteria as source of AF agents towards invertebrate macrofouling species.

  18. Genomic and Proteomic Studies on the Mode of Action of Oxaboroles against the African Trypanosome.

    Directory of Open Access Journals (Sweden)

    Deuan C Jones

    2015-12-01

    Full Text Available SCYX-7158, an oxaborole, is currently in Phase I clinical trials for the treatment of human African trypanosomiasis. Here we investigate possible modes of action against Trypanosoma brucei using orthogonal chemo-proteomic and genomic approaches. SILAC-based proteomic studies using an oxaborole analogue immobilised onto a resin was used either in competition with a soluble oxaborole or an immobilised inactive control to identify thirteen proteins common to both strategies. Cell-cycle analysis of cells incubated with sub-lethal concentrations of an oxaborole identified a subtle but significant accumulation of G2 and >G2 cells. Given the possibility of compromised DNA fidelity, we investigated long-term exposure of T. brucei to oxaboroles by generating resistant cell lines in vitro. Resistance proved more difficult to generate than for drugs currently used in the field, and in one of our three cell lines was unstable. Whole-genome sequencing of the resistant cell lines revealed single nucleotide polymorphisms in 66 genes and several large-scale genomic aberrations. The absence of a simple consistent mechanism among resistant cell lines and the diverse list of binding partners from the proteomic studies suggest a degree of polypharmacology that should reduce the risk of resistance to this compound class emerging in the field. The combined genetic and chemical biology approaches have provided lists of candidates to be investigated for more detailed information on the mode of action of this promising new drug class.

  19. Mode of Action of the Natural Insecticide, Decaleside Involves Sodium Pump Inhibition.

    Science.gov (United States)

    Rajashekar, Yallappa; Shivanandappa, Thimmappa

    2017-01-01

    Decalesides are a new class of natural insecticides which are toxic to insects by contact via the tarsal gustatory chemosensilla. The symptoms of their toxicity to insects and the rapid knockdown effect suggest neurotoxic action, but the precise mode of action and the molecular targets for decaleside action are not known. We have presented experimental evidence for the involvement of sodium pump inhibition in the insecticidal action of decaleside in the cockroach and housefly. The knockdown effect of decaleside is concomitant with the in vivo inhibition of Na+, K+ -ATPase in the head and thorax. The lack of insecticidal action by experimental ablation of tarsi or blocking the tarsal sites with paraffin correlated with lack of inhibition of Na+- K+ ATPase in vivo. Maltotriose, a trisaccharide, partially rescued the toxic action of decaleside as well as inhibition of the enzyme, suggesting the possible involvement of gustatory sugar receptors. In vitro studies with crude insect enzyme preparation and purified porcine Na+, K+ -ATPase showed that decaleside competitively inhibited the enzyme involving the ATP binding site. Our study shows that the insecticidal action of decaleside via the tarsal gustatory sites is causally linked to the inhibition of sodium pump which represents a unique mode of action. The precise target(s) for decaleside in the tarsal chemosensilla and the pathway linked to inhibition of sodium pump and the insecticidal action remain to be understood.

  20. Understanding the cellular mode of action of vernakalant using a computational model: answers and new questions

    Directory of Open Access Journals (Sweden)

    Loewe Axel

    2015-09-01

    Full Text Available Vernakalant is a new antiarrhythmic agent for the treatment of atrial fibrillation. While it has proven to be effective in a large share of patients in clinical studies, its underlying mode of action is not fully understood. In this work, we aim to link experimental data from the subcellular, tissue, and system level using an in-silico approach. A Hill’s equation-based drug model was extended to cover the frequency dependence of sodium channel block. Two model variants were investigated: M1 based on subcellular data and M2 based on tissue level data. 6 action potential (AP markers were evaluated regarding their dose, frequency and substrate dependence. M1 comprising potassium, sodium, and calcium channel block reproduced the reported prolongation of the refractory period. M2 not including the effects on potassium channels reproduced reported AP morphology changes on the other hand. The experimentally observed increase of ERP accompanied by a shortening of APD90 was not reproduced. Thus, explanations for the drug-induced changes are provided while none of the models can explain the effects in their entirety. These results foster the understanding of vernakalant’s cellular mode of action and point out relevant gaps in our current knowledge to be addressed in future in-silico and experimental research on this aspiring antiarrhythmic agent.

  1. Elucidating Duramycin’s Bacterial Selectivity and Mode of Action on the Bacterial Cell Envelope

    Directory of Open Access Journals (Sweden)

    Sahar Hasim

    2018-02-01

    Full Text Available The use of naturally occurring antimicrobial peptides provides a promising route to selectively target pathogenic agents and to shape microbiome structure. Lantibiotics, such as duramycin, are one class of bacterially produced peptidic natural products that can selectively inhibit the growth of other bacteria. However, despite longstanding characterization efforts, the microbial selectivity and mode of action of duramycin are still obscure. We describe here a suite of biological, chemical, and physical characterizations that shed new light on the selective and mechanistic aspects of duramycin activity. Bacterial screening assays have been performed using duramycin and Populus-derived bacterial isolates to determine species selectivity. Lipidomic profiles of selected resistant and sensitive strains show that the sensitivity of Gram-positive bacteria depends on the presence of phosphatidylethanolamine (PE in the cell membrane. Further the surface and interface morphology were studied by high resolution atomic force microscopy and showed a progression of cellular changes in the cell envelope after treatment with duramycin for the susceptible bacterial strains. Together, these molecular and cellular level analyses provide insight into duramycin’s mode of action and a better understanding of its selectivity.

  2. Acute toxicity of 8 antidepressants: what are their modes of action?

    Science.gov (United States)

    Minguez, Laetitia; Farcy, Emilie; Ballandonne, Céline; Lepailleur, Alban; Serpentini, Antoine; Lebel, Jean-Marc; Bureau, Ronan; Halm-Lemeille, Marie-Pierre

    2014-08-01

    Currently, the hazard posed by pharmaceutical residues is a major concern of ecotoxicology. Most of the antidepressants belong to a family named the Cationic Amphipathic Drugs known to have specific interactions with cell membranes. The present study assessed the impact of eight antidepressants belonging to selective serotonin reuptake inhibitors or serotonin norepinephrine reuptake inhibitors by the combination of multi-approaches (in vivo, in vitro, in silico) and gives some insights on the mode of action for these molecules. Antidepressants were from the most to the least toxic compound for Daphnia magna: Sertraline (EC50=1.15 mg L(-1))>Clomipramine (2.74 mg L(-1))>Amitriptyline (4.82 mg L(-1))>Fluoxetine (5.91 mg L(-1))>Paroxetine (6.24 mg L(-1))>Mianserine (7.81 mg L(-1))>Citalopram (30.14 mg L(-1)) and Venlafaxine (141.28 mg L(-1)). These acute toxicities were found correlated to Log Kow coefficients (R=0.93, pantidepressants and phosphatidylcholine, a major component of cell membranes, leading to a more specific mode of action corresponding to a potential acidic hydrolysis of ester functions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Mode of Action of the Natural Insecticide, Decaleside Involves Sodium Pump Inhibition.

    Directory of Open Access Journals (Sweden)

    Yallappa Rajashekar

    Full Text Available Decalesides are a new class of natural insecticides which are toxic to insects by contact via the tarsal gustatory chemosensilla. The symptoms of their toxicity to insects and the rapid knockdown effect suggest neurotoxic action, but the precise mode of action and the molecular targets for decaleside action are not known. We have presented experimental evidence for the involvement of sodium pump inhibition in the insecticidal action of decaleside in the cockroach and housefly. The knockdown effect of decaleside is concomitant with the in vivo inhibition of Na+, K+ -ATPase in the head and thorax. The lack of insecticidal action by experimental ablation of tarsi or blocking the tarsal sites with paraffin correlated with lack of inhibition of Na+- K+ ATPase in vivo. Maltotriose, a trisaccharide, partially rescued the toxic action of decaleside as well as inhibition of the enzyme, suggesting the possible involvement of gustatory sugar receptors. In vitro studies with crude insect enzyme preparation and purified porcine Na+, K+ -ATPase showed that decaleside competitively inhibited the enzyme involving the ATP binding site. Our study shows that the insecticidal action of decaleside via the tarsal gustatory sites is causally linked to the inhibition of sodium pump which represents a unique mode of action. The precise target(s for decaleside in the tarsal chemosensilla and the pathway linked to inhibition of sodium pump and the insecticidal action remain to be understood.

  4. Enhanced Performance and Mode of Action of a Novel Antibiofilm Hydrofiber® Wound Dressing

    Directory of Open Access Journals (Sweden)

    David Parsons

    2016-01-01

    Full Text Available Biofilm development in wounds is now acknowledged to be a precursor to infection and a cause of delayed healing. A next-generation antibiofilm carboxymethylcellulose silver-containing wound dressing (NGAD has been developed to disrupt and kill biofilm microorganisms. This in vitro study aimed to compare its effectiveness against various existing wound dressings and examine its mode of action. A number of biofilm models of increasing complexity were used to culture biofilms of wound-relevant pathogens, before exposure to test dressings. Confocal microscopy, staining, and imaging of biofilm constituents, total viable counting, and elemental analysis were conducted to assess dressing antibiofilm performance. Live/dead staining and viable counting of biofilms demonstrated that the NGAD was more effective at killing biofilm bacteria than two other standard silver dressings. Staining of biofilm polysaccharides showed that the NGAD was also more effective at reducing this protective biofilm component than standard silver dressings, and image analyses confirmed the superior biofilm killing and removal performance of the NGAD. The biofilm-disruptive and silver-enhancing modes of action of the NGAD were supported by significant differences (p<0.05 in biofilm elemental markers and silver donation. This in vitro study improves our understanding of how antibiofilm dressing technology can be effective against the challenge of biofilm.

  5. Enhanced Performance and Mode of Action of a Novel Antibiofilm Hydrofiber® Wound Dressing.

    Science.gov (United States)

    Parsons, David; Meredith, Kate; Rowlands, Victoria J; Short, Darryl; Metcalf, Daniel G; Bowler, Philip G

    2016-01-01

    Biofilm development in wounds is now acknowledged to be a precursor to infection and a cause of delayed healing. A next-generation antibiofilm carboxymethylcellulose silver-containing wound dressing (NGAD) has been developed to disrupt and kill biofilm microorganisms. This in vitro study aimed to compare its effectiveness against various existing wound dressings and examine its mode of action. A number of biofilm models of increasing complexity were used to culture biofilms of wound-relevant pathogens, before exposure to test dressings. Confocal microscopy, staining, and imaging of biofilm constituents, total viable counting, and elemental analysis were conducted to assess dressing antibiofilm performance. Live/dead staining and viable counting of biofilms demonstrated that the NGAD was more effective at killing biofilm bacteria than two other standard silver dressings. Staining of biofilm polysaccharides showed that the NGAD was also more effective at reducing this protective biofilm component than standard silver dressings, and image analyses confirmed the superior biofilm killing and removal performance of the NGAD. The biofilm-disruptive and silver-enhancing modes of action of the NGAD were supported by significant differences ( p silver donation. This in vitro study improves our understanding of how antibiofilm dressing technology can be effective against the challenge of biofilm.

  6. Caffeine and other sympathomimetic stimulants: modes of action and effects on sports performance.

    Science.gov (United States)

    Jones, Gareth

    2008-01-01

    Stimulants, illegal and legal, continue to be used in competitive sport. The evidence for the ergogenic properties of the most potent stimulants, amphetamines, cocaine and ephedrine, is mostly insubstantial. Low doses of amphetamines may aid performance where effects of fatigue adversely affect higher psychomotor activity. Pseudoephedrine, at high doses, has been suggested to improve high intensity and endurance exercise but phenylpropanolamine has not been proven to be ergogenic. Only caffeine has substantial experimental backing for being ergogenic in exercise. The mode of action of these stimulants centres on their ability to cause persistence of catecholamine neurotransmitters, with the exception of caffeine which is an adenosine receptor antagonist. By these actions, the stimulants are able to influence the activity of neuronal control pathways in the central (and peripheral) nervous system. Rodent models suggest that amphetamines and cocaine interact with different pathways to that affected by caffeine. Caffeine has a variety of pharmacological effects but its affinity for adenosine receptors is comparable with the levels expected to exist in the body after moderate caffeine intake, thus making adenosine receptor blockade the favoured mode of ergogenic action. However, alternative modes of action to account for the ergogenic properties of caffeine have been supported in the literature. Biochemical mechanisms that are consistent with more recent research findings, involving proteins such as DARPP-32 (dopamine and cAMP-regulated phosphoprotein), are helping to rationalize the molecular details of stimulant action in the central nervous system.

  7. Implications of dibenzyl trisulphide for disease treatment based on its mode of action.

    Science.gov (United States)

    Williams, L A D; Barton, E N; Kraus, W; Rösner, H

    2009-11-01

    Studies conducted on the secondary metabolite (natural product), dibenzyl trisulphide (DTS), which was isolated from the sub-tropical shrub Petiveria alliacea (guinea hen weed, anamu) [Phytolaccaceae] have shown tremendous pharmaceutical promise as a drug prototype. This is now reflected in the development of the broad spectrum anti-cancer molecule, fluorapacin (bis(4-fluorobenzyl) trisulphide) which has an excellent safety profile. The mode of action elucidated for DTS is the mitogen activated protein extracellular regulated kinases 1 and 2 (MAPKinases ERK 1 and ERK 2). The MAPKinase signal transduction biochemical pathways are important in the regulation of a wide range of cellular processes which are important in disease establishment. These processes include: cancer cell proliferation, nerve repair, memory enhancement, autoimmune diseases, which are linked to thymic cell involution and bone marrow functions, cerebrovascular and cardiovascular diseases. In addition to the MAPkinase signal transduction mode of action, DTS also prevents the denaturation of serum albumin which is a feature of nonsteroidal anti-inflammatory drugs, thus supporting the molecule's possible role in the treatment of inflammatory ageing diseases.

  8. Anti-dengue virus serotype 2 activity and mode of action of a novel peptide.

    Science.gov (United States)

    Chew, M-F; Tham, H-W; Rajik, M; Sharifah, S H

    2015-10-01

    To identify a novel antiviral peptide against dengue virus serotype 2 (DENV-2) by screening a phage display peptide library and to evaluate its in vitro antiviral activity and mode of action. A phage display peptide library was biopanned against purified DENV-2 and resulted in the identification and selection of a peptide (peptide gg-ww) for further investigation. ELISA was performed, and peptide gg-ww was shown to possess the highest binding affinity against DENV-2. Thus, peptide gg-ww was synthesized for cytotoxicity and antiviral assays. Virus plaque reduction assay, real-time PCR and immunofluorescence assay were used to investigate the inhibitory effect of peptide gg-ww on DENV-2 infection in Vero cells. Three different assays (pre-, simultaneous and post-treatments assays) were performed to investigate the peptide's mode of action. Results indicated that peptide gg-ww possessed strong antiviral activity with a ~96% inhibition rate, which was achieved at 250 μmol l(-1) . Viral replication was inhibited during a simultaneous treatment assay, indicating that the entry of the virus was impeded by this peptide. Peptide gg-ww displayed antiviral action against DENV-2 by targeting an early stage of viral replication (i.e. during viral entry). Peptide gg-ww may represent a new therapeutic candidate for the treatment of DENV infections and is a potential candidate to be developed as a peptide drug. © 2015 The Society for Applied Microbiology.

  9. Exploring the Modes of Action of Phosphorus-Based Flame Retardants in Polymeric Systems

    Directory of Open Access Journals (Sweden)

    Sebastian Rabe

    2017-04-01

    Full Text Available Phosphorus-based flame retardants were incorporated into different, easily preparable matrices, such as polymeric thermoset resins and paraffin as a proposed model for polyolefins and investigated for their flame retardancy performance. The favored mode of action of each flame retardant was identified in each respective system and at each respective concentration. Thermogravimetric analysis was used in combination with infrared spectroscopy of the evolved gas to determine the pyrolysis behavior, residue formation and the release of phosphorus species. Forced flaming tests in the cone calorimeter provided insight into burning behavior and macroscopic residue effects. The results were put into relation to the phosphorus content to reveal correlations between phosphorus concentration in the gas phase and flame inhibition performance, as well as phosphorus concentration in the residue and condensed phase activity. Total heat evolved (fire load and peak heat release rate were calculated based on changes in the effective heat of combustion and residue, and then compared with the measured values to address the modes of action of the flame retardants quantitatively. The quantification of flame inhibition, charring, and the protective layer effect measure the non-linear flame retardancy effects as functions of the phosphorus concentration. Overall, this screening approach using easily preparable polymer systems provides great insight into the effect of phosphorus in different flame retarded polymers, with regard to polymer structure, phosphorus concentration, and phosphorus species.

  10. Taxonomic distribution and origins of the extended LHC (light-harvesting complex antenna protein superfamily

    Directory of Open Access Journals (Sweden)

    Brinkmann Henner

    2010-07-01

    Full Text Available Abstract Background The extended light-harvesting complex (LHC protein superfamily is a centerpiece of eukaryotic photosynthesis, comprising the LHC family and several families involved in photoprotection, like the LHC-like and the photosystem II subunit S (PSBS. The evolution of this complex superfamily has long remained elusive, partially due to previously missing families. Results In this study we present a meticulous search for LHC-like sequences in public genome and expressed sequence tag databases covering twelve representative photosynthetic eukaryotes from the three primary lineages of plants (Plantae: glaucophytes, red algae and green plants (Viridiplantae. By introducing a coherent classification of the different protein families based on both, hidden Markov model analyses and structural predictions, numerous new LHC-like sequences were identified and several new families were described, including the red lineage chlorophyll a/b-binding-like protein (RedCAP family from red algae and diatoms. The test of alternative topologies of sequences of the highly conserved chlorophyll-binding core structure of LHC and PSBS proteins significantly supports the independent origins of LHC and PSBS families via two unrelated internal gene duplication events. This result was confirmed by the application of cluster likelihood mapping. Conclusions The independent evolution of LHC and PSBS families is supported by strong phylogenetic evidence. In addition, a possible origin of LHC and PSBS families from different homologous members of the stress-enhanced protein subfamily, a diverse and anciently paralogous group of two-helix proteins, seems likely. The new hypothesis for the evolution of the extended LHC protein superfamily proposed here is in agreement with the character evolution analysis that incorporates the distribution of families and subfamilies across taxonomic lineages. Intriguingly, stress-enhanced proteins, which are universally found in the

  11. The enzymatic hydrolysis of pretreated pulp fibers predominantly involves "peeling/erosion" modes of action.

    Science.gov (United States)

    Arantes, Valdeir; Gourlay, Keith; Saddler, Jack N

    2014-01-01

    There is still considerable debate regarding the actual mechanism by which a "cellulase mixture" deconstructs cellulosic materials, with accessibility to the substrate at the microscopic level being one of the major restrictions that limits fast, complete cellulose hydrolysis. In the work reported here we tried to determine the predominant mode of action, at the fiber level, of how a cellulase mixture deconstructs pretreated softwood and hardwood pulp fibers. Quantitative changes in the pulp fibers derived from different pretreated biomass substrates were monitored throughout the course of enzymatic hydrolysis to see if the dominant mechanisms involved either the fragmentation/cutting of longer fibers to shorter fibers or their "peeling/delamination/erosion," or if both cutting and peeling mechanisms occurred simultaneously. Regardless of the source of biomass, the type of pretreatment and the chemical composition of the substrate, under typical hydrolysis conditions (50°C, pH 4.8, mixing) longer pulp fibers (fiber length >200 μm) were rapidly broken down until a relatively constant fiber length of 130 to 160 μm was reached. In contrast, shorter fibers with an initial average fiber length of 130 to 160 μm showed no significant change in length despite their substantial hydrolysis. The fragmentation/cutting mode of deconstruction was only observed on longer fibers at early stages of hydrolysis. Although the fiber fragmentation mode of deconstruction was not greatly influenced by enzyme loading, it was significantly inhibited by glucose and was mainly observed during initial mixing of the enzyme and substrate. In contrast, significant changes in the fiber width occurred throughout the course of hydrolysis for all of the substrates, suggesting that fiber width may limit the rate and extent of cellulose hydrolysis. It appears that, at the fiber level, pretreated pulp fibers are hydrolyzed through a two-step mode of action involving an initial rapid

  12. Phylogenetic analysis reveals the taxonomically diverse distribution of the Pseudomonas putida group.

    Science.gov (United States)

    Yonezuka, Kenta; Shimodaira, Jun; Tabata, Michiro; Ohji, Shoko; Hosoyama, Akira; Kasai, Daisuke; Yamazoe, Atsushi; Fujita, Nobuyuki; Ezaki, Takayuki; Fukuda, Masao

    2017-03-17

    Pseudomonas putida is well-known for degradation activities for a variety of compounds and its infections have been reported. Thus, P. putida includes both clinical and nonclinical isolates. To date, no reports have examined the phylogenetic relationship between clinical and nonclinical isolates of the P. putida group. In this study, fifty-nine strains of P. putida group containing twenty-six clinical, and thirty-three nonclinical, isolates, were subjected to phylogenetic and taxonomic analyses based on 16S rRNA gene sequences and nine housekeeping gene sequences, including argS, dnaN, dnaQ, era, gltA, gyrB, ppnK, rpoB, and rpoD, to obtain insights into the diversity of species in this group. More than 97.6% similarity was observed among the 16S rRNA gene sequences of all the strains examined, indicating that the resolution of 16S rRNA gene sequences is inadequate. Phylogenetic analysis based on the individual housekeeping genes listed above improved the resolution of the phylogenetic trees, which are different from each other. Multilocus sequence analysis (MLSA) based on the concatenated sequences of the nine genes significantly improved the resolution of the phylogenetic tree, and yielded approximately the same results as average nucleotide identity (ANI) analysis, suggesting its high reliability. ANI analysis classified the fifty-nine strains into twenty-six species containing seventeen singletons and nine strain clusters based on the 95% threshold. It also indicated the mixed distribution of clinical and nonclinical isolates in the six clusters, suggesting that the genomic difference between clinical and nonclinical isolates of the P. putida group is subtle. The P. putida type strain NBRC 14164 T is a singleton that is independently located from the P. putida strains distributed among the six clusters, suggesting that the classification of these strains and the differentiation of species in the P. putida group should be re-examined. This study greatly expands

  13. Probiotics as beneficial microbes in aquaculture: an update on their multiple modes of action: a review

    DEFF Research Database (Denmark)

    Zorriehzahra, Mohammad Jalil; Delshad, Somayeh Torabi; Adel, Milad

    2016-01-01

    Wide and discriminate use of antibiotics has resulted in serious biological and ecological concerns, especially the emergence of antibiotic resistance. Probiotics, known as beneficial microbes, are being proposed as an effective and eco-friendly alternative to antibiotics. They were first applied...... in aquaculture species more than three decades ago, but considerable attention had been given only in the early 2000s. Probiotics are defined as live or dead, or even a component of the microorganisms that act under different modes of action in conferring beneficial effects to the host or to its environment....... Several probiotics have been characterized and applied in fish and a number of them are of host origin. Unlike some disease control alternatives being adapted and proposed in aquaculture where actions are unilateral, the immense potential of probiotics lies on their multiple mechanisms in conferring...

  14. Mode of action classification of chemicals using multi-concentration time-dependent cellular response profiles.

    Science.gov (United States)

    Xi, Zhankun; Khare, Swanand; Cheung, Aaron; Huang, Biao; Pan, Tianhong; Zhang, Weiping; Ibrahim, Fadi; Jin, Can; Gabos, Stephan

    2014-04-01

    In this paper, we present a new statistical pattern recognition method for classifying cytotoxic cellular responses to toxic agents. The advantage of the proposed method is to quickly assess the toxicity level of an unclassified toxic agent on human health by bringing cytotoxic cellular responses with similar patterns (mode of action, MoOA) into the same class. The proposed method is a model-based hierarchical classification approach incorporating principal component analysis (PCA) and functional data analysis (FDA). The cytotoxic cell responses are represented by multi-concentration time-dependent cellular response profiles (TCRPs) which are dynamically recorded by using the xCELLigence real-time cell analysis high-throughput (RTCA HT) system. The classification results obtained using our algorithm show satisfactory discrimination and are validated using biological facts by examining common chemical mechanisms of actions with treatment on human hepatocellular carcinoma cells (HepG2). Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Reconsidering the nature and mode of action of metabolite retrograde signals from the chloroplast

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    Gonzalo Martín Estavillo

    2013-01-01

    Full Text Available Plant organelles produce retrograde signals to alter nuclear gene expression in order to coordinate their biogenesis, maintain homeostasis or optimize their performance under adverse conditions. Many signals of different chemical nature have been described in the past decades, including chlorophyll intermediates, reactive oxygen species and adenosine derivatives. While the effects of retrograde signalling on gene expression are well understood, the initiation and transport of the signals and their mode of action have either not been resolved, or are a matter of speculation. Moreover, retrograde signalling should be consider as part of a broader cellular network, instead of as separate pathways, required to adjust to changing physiologically relevant conditions. Here we summarize current plastid retrograde signalling models in plants, with a focus on new signalling pathways, SAL1-PAP, MEcPP and β- cyclocitral, and outline missing links or future areas of research that we believe need to be addressed to have a better understanding of plant intracellular signalling networks.

  16. Development and implementation of the IPCS conceptual framework for evaluating mode of action of chemical carcinogens.

    Science.gov (United States)

    Dybing, E

    2002-12-27

    The framework developed by the International Programme on Chemical Safety (IPCS) for assessing the mode of action of tumour induction of chemicals in experimental animals has been illustrated with d-limonene, sodium saccharin, di(2-ethylhexyl)phthalate (DEHP) and sulfamethazine as examples. d-Limonene causes renal tumours only in male rats through a response associated with alpha(2u)-globulin. Sodium saccharin induces urinary bladder tumours only in male rats through formation of a urinary precipitate causing erosion of the bladder surface and extensive regenerative hyperplasia. DEHP causes liver tumours in rats and mice through activation of the receptor PPAR alpha leading to peroxisome proliferation and hepatocellular proliferation. Sulfamethazine induces thyroid follicular cell tumours in rats and mice through a mechanism involving altered thyroid hormone homeostasis.

  17. Gallesia integrifolia (Spreng.) Harms: In vitro and in vivo antibacterial activities and mode of action.

    Science.gov (United States)

    Arunachalam, Karuppusamy; Ascêncio, Sérgio Donizeti; Soares, Ilsamar Mendes; Souza Aguiar, Raimundo Wagner; da Silva, Larissa Irene; de Oliveira, Ruberlei Godinho; Balogun, Sikiru Olaitan; de Oliveira Martins, Domingos Tabajara

    2016-05-26

    Gallesia integrifolia (Phytolaccaceae) is commonly known as "pau-d'alho" in Brazil or "garlic plant" due to the strong scent of garlic peculiar to all parts of the plant. The bark decoction is used for the treatment of microbial infections among other diseases by different ethnic groups in Brazil, Peruvian Amazonians, Bolivia and Mosetene Indians. This study aimed to advance in the antibacterial activity and characterize the mode of action of the hydroethanolic extract of the inner stem bark of G. integrifolia (HEGi) using in vivo and in vitro experimental models. The qualitative and quantitative phytochemical analyzes of HEGi were carried out using colorimetric and HPLC technique. The cytotoxic potential of HEGi was evaluated against CHO-K1 cells by Alamar blue assay and its acute toxicity was assessed by the Hippocratic screening test using Swiss-Webster mice. The antibacterial activity was evaluated by micro- dilution method against ten strains of Gram-positive and Gram-negative bacteria. The mode of action of HEGi was investigated by outer membrane permeability, nucleotide leakage and potassium efflux assays. In vivo infection model was established by using Staphylococcus aureus infection model Wistar rats. Qualitative phytochemical analysis of HEGi revealed the presence of saponins, alkaloids, phenolic compounds and flavonoids. Phytochemical quantification of HEGi showed that higher total phenolic (80.10±0.62mg GAE/g) and flavonoid (16.10±0.03mg RE/g) contents. HPLC fingerprint analysis revealed the presence of gallic acid, rutin, and morin. In the Alamar blue assay no cytotoxic effect of HEGi in CHO-K1 cells was observed up to 200µg/mL, and no signs or symptoms of acute toxicity were observed in mice of both sexes at higher doses of up to 2000mg/kg, p.o. HEGi demonstrated bacteriostatic effect against selected Gram positive and Gram negative bacterial pathogens. Its mode of action is associated, at least partly, with changes in the permeability of

  18. Nanovesicle encapsulation of antimicrobial peptide P34: physicochemical characterization and mode of action on Listeria monocytogenes

    Science.gov (United States)

    da Silva Malheiros, Patrícia; Sant'Anna, Voltaire; Micheletto, Yasmine Miguel Serafini; da Silveira, Nadya Pesce; Brandelli, Adriano

    2011-08-01

    Antimicrobial peptide P34, a substance showing antibacterial activity against pathogenic and food spoilage bacteria, was encapsulated in liposomes prepared from partially purified soybean phosphatidylcholine, and their physicochemical characteristics were evaluated. The antimicrobial activity was estimated by agar diffusion assay using Listeria monocytogenes ATCC 7644 as indicator strain. A concentration of 3,200 AU/mL of P34 was encapsulated in nanovesicles and stocked at 4 °C. No significant difference ( p > 0.05) in the biological activity of free and encapsulated P34 was observed through 24 days. Size and PDI of liposomes, investigated by light scattering analysis, were on average 150 nm and 0.22 respectively. Zeta potential was -27.42 mV. There was no significant change ( p > 0.05) in the physicochemical properties of liposomes during the time of evaluation. The liposomes presented closed spherical morphology as visualized by transmission electron microscopy (TEM). The mode of action of liposome-encapsulated P34 under L. monocytogenes cells was investigated by TEM. Liposomes appeared to adhere but not fuse with the bacterial cell wall, suggesting that the antimicrobial is released from nanovesicles to act against the microorganism. The effect of free and encapsulated P34 was tested against L. monocytogenes, showing that free bacteriocin inhibited the pathogen more quickly than the encapsulated P34. Liposomes prepared with low-cost lipid showed high encapsulation efficiency for a new antimicrobial peptide and were stable during storage. The mode of action against the pathogen L. monocytogenes was characterized.

  19. Synergistic interaction and mode of action of Citrus hystrix essential oil against bacteria causing periodontal diseases.

    Science.gov (United States)

    Wongsariya, Karn; Phanthong, Phanida; Bunyapraphatsara, Nuntavan; Srisukh, Vimol; Chomnawang, Mullika Traidej

    2014-03-01

    Citrus hystrix de Candolle (Rutaceae), an edible plant regularly used as a food ingredient, possesses antibacterial activity, but there is no current data on the activity against bacteria causing periodontal diseases. C. hystrix essential oil from leaves and peel were investigated for antibiofilm formation and mode of action against bacteria causing periodontal diseases. In vitro antibacterial and antibiofilm formation activities were determined by broth microdilution and time kill assay. Mode of action of essential oil was observed by SEM and the active component was identified by bioautography and GC/MS. C. hystrix leaves oil exhibited antibacterial activity at the MICs of 1.06 mg/mL for P. gingivalis and S. mutans and 2.12 mg/mL for S. sanguinis. Leaf oil at 4.25 mg/mL showed antibiofilm formation activity with 99% inhibition. The lethal effects on P. gingivalis were observed within 2 and 4 h after treated with 4 × MIC and 2 × MIC, respectively. S. sanguinis and S. mutans were completely killed within 4 and 8 h after exposed to 4 × MIC and 2 × MIC of oil. MICs of tested strains showed 4 times reduction suggesting synergistic interaction of oil and chlorhexidine. Bacterial outer membrane was disrupted after treatment with leaves oil. Additionally, citronellal was identified as the major active compound of C. hystrix oil. C. hystrix leaf oil could be used as a natural active compound or in combination with chlorhexidine in mouthwash preparations to prevent the growth of bacteria associated with periodontal diseases and biofilm formation.

  20. EEG alpha activity reflects motor preparation rather than the mode of action selection

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    Marie-Pierre eDeiber

    2012-08-01

    Full Text Available Alpha-band activity (8-13 Hz is suppressed by sensory stimulation and movements, modulated by attention, working memory and mental tasks and may be sensitive to higher motor control functions. The aim of the present study was to examine alpha oscillatory activity during the preparation of simple left or right finger movements, contrasting the external and internal mode of action selection. Three preparation conditions were examined using a precueing paradigm with S1 as the preparatory and S2 as the imperative cue: Full, laterality instructed by S1; Free, laterality freely selected and None, laterality instructed by S2. Time-frequency analysis was performed in the alpha frequency range during the S1-S2 interval, and alpha motor-related amplitude asymmetries (MRAA were also calculated. The significant MRAA during the Full and Free conditions indicated effective external and internal motor response preparation. In the absence of specific motor preparation (None, a posterior alpha power decrease (event-related desynchronization, ERD dominated, reflecting the main engagement of attentional resources. In Full and Free motor preparation, posterior alpha ERD was accompanied by a midparietal alpha power increase (event-related synchronization, ERS, suggesting a concomitant inhibition of task-irrelevant visual activity. In both Full and Free motor preparation, analysis of alpha power according to MRAA amplitude revealed two types of functional activation patterns: 1 a motor alpha pattern, with predominantly midparietal alpha ERS and large MRAA corresponding to lateralized motor activation/visual inhibition and 2 an attentional alpha pattern, with dominating right posterior alpha ERD and small MRAA reflecting visuospatial attention. The present results suggest that alpha oscillatory patterns do not resolve the selection mode of action, but rather distinguish separate functional strategies of motor preparation. 

  1. Antibiotic resistance modulation and modes of action of (--α-pinene in Campylobacter jejuni.

    Directory of Open Access Journals (Sweden)

    Jasna Kovač

    Full Text Available The aim of the study was to investigate the mode of action of (--α-pinene in terms of its modulation of antibiotic resistance in Campylobacter jejuni. Broth microdilution and ethidium bromide accumulation assays were used to evaluate the (--α-pinene antimicrobial activity, modulation of antimicrobial resistance, and inhibition of antimicrobial efflux. The target antimicrobial efflux systems were identified using an insertion mutagenesis approach, and C. jejuni adaptation to (--α-pinene was evaluated using DNA microarrays. Knock-out mutants of the key up-regulated transcriptional regulators hspR and hrcA were constructed to investigate their roles in C. jejuni adaptation to several stress factors, including osmolytes, and pH, using Biolog phenotypical microarrays. Our data demonstrate that (--α-pinene efficiently modulates antibiotic resistance in C. jejuni by decreasing the minimum inhibitory concentrations of ciprofloxacin, erythromycin and triclosan by up to 512-fold. Furthermore, (--α-pinene promotes increased expression of cmeABC and another putative antimicrobial efflux gene, Cj1687. The ethidium bromide accumulation was greater in the wild-type strain than in the antimicrobial efflux mutant strains, which indicates that these antimicrobial efflux systems are a target of action of (--α-pinene. Additionally, (--α-pinene decreases membrane integrity, which suggests that enhanced microbial influx is a secondary mode of action of (--α-pinene. Transcriptomic analysis indicated that (--α-pinene disrupts multiple metabolic pathways, and particularly those involved in heat-shock responses. Thus, (--α-pinene has significant activity in the modulation of antibiotic resistance in C. jejuni, which appears to be mediated by multiple mechanisms that include inhibition of microbial efflux, decreased membrane integrity, and metabolic disruption. These data warrant further studies on (--α-pinene to develop its use in the control of antibiotic

  2. The synergy and mode of action of quercetin plus amoxicillin against amoxicillin-resistant Staphylococcus epidermidis.

    Science.gov (United States)

    Siriwong, Supatcharee; Teethaisong, Yothin; Thumanu, Kanjana; Dunkhunthod, Benjawan; Eumkeb, Griangsak

    2016-08-04

    Staphylococcus epidermidis is one of the most multiple resistances to antibiotics in the recent years. Therefore, practically-prescribed antibiotics in the treatment of these strains are not effective. Plant-derived antibacterial is one of the most interesting sources of new therapeutics. The present study was to investigate antibacterial, synergy and modes of action of quercetin and amoxicillin against amoxicillin-resistant Staphylococcus epidermidis (ARSE). The MICs, checkerboard assay, viability curves, cytoplasmic membrane (CM) permeability, enzyme assay, transmission electron microscopy, confocal microscopy and FT-IR microspectroscopy measurement was performed. The MICs of amoxicillin, penicillin, quercetin and kaempferol against all ARSE strains were 16, 200, 256-384 and >1024 μg/mL respectively. Synergistic effects were exhibited on amoxicillin plus quercetin and penicillin plus kaempferol against these strains at FIC index 0.50 and amoxicillin was confirmed by the viable count. This combination increased CM permeability, caused marked morphological, peptidoglycan and cytoplasmic membrane damage, increased protein amide I and II, but decreased fatty acid in bacterial cells. The quercetin had an inhibitory activity against β-lactamase. So, these findings are the first report that quercetin has the synergistic effect with amoxicillin against ARSE via four modes of actions, inhibit peptidoglycan synthesis and β-lactamases activity, increase CM permeability and protein amide I and II but decrease fatty acid in bacterial cells. Of course, this flavonol has the dominant potential to develop a brand-new collateral phytochemical agent plus amoxicillin to treat ARSE. Future work should focus on the bioavailability, efficacy and toxicity in animal and human studies, as well as, the synergistic effect on blood and tissue should be evaluated and achieved.

  3. Physiological modes of action of fluoxetine and its human metabolites in algae.

    Science.gov (United States)

    Neuwoehner, Judith; Fenner, Kathrin; Escher, Beate I

    2009-09-01

    Fluoxetine, the active ingredient of many antidepressants, was identified as specifically toxic toward algae in a quantitative structure-activity relationship (QSAR) analysis with literature data for algae, daphnia, and fish. The goal of this study was to elucidate the mode of action in algae and to evaluate the toxicity of the major human metabolites of fluoxetine using two different algae tests. The time dependence and sensitivity of thedifferenteffectendpointsyield information on the physiological mode of action. Baseline toxicity was predicted with QSARs based on measured liposome-water partition coefficients. The ratio of predicted baseline toxicity to experimental toxicity (toxic ratio TR) gives information on the intrinsic potency (extent of specificity of effect). The metabolite p-trifluoromethylphenol was classified to act as baseline toxicant Fluoxetine (TR 60-150) and its pharmacologically active metabolite norfluoxetine (TR 10-80) exhibited specific toxicity. By comparison with reference compounds we conclude that fluoxetine and norfluoxetine have an effect on the energy budget of algal cells since the time pattern of these two compounds is most similar to that observed for norflurazon, but they act less specifically as indicated by lower TR values and the similarity of the effect pattern to baseline toxicants. The mixture toxicity of fluoxetine and its human metabolites norfluoxetine and p-TFMP can be predicted using the model of concentration addition for practical purposes of risk assessment despite small deviations from this model for the specific endpoints like PSII inhibition because the integrative endpoints like growth rate and reproduction in all cases gave agreement with the predictions for concentration addition.

  4. Caloplaca subpallida (Teloschistaceae, a lichen species new to Poland: distribution, ecology and taxonomic affinities

    Directory of Open Access Journals (Sweden)

    Katarzyna Szczepańska

    2013-03-01

    Full Text Available Caloplaca subpallida is reported from basic and altered ultrabasic rocks (i.e. basalt, greenstone, and serpentinite at nine sites in SW Poland. A detailed description of the species and a discussion on its taxonomic affinities are provided.

  5. Treatment of parasitic skin diseases with dimeticones a new family of compounds with a purely physical mode of action.

    Science.gov (United States)

    Feldmeier, Hermann

    2014-06-01

    Epidermal parasitic skin diseases (EPSD) are common in the tropics and sub-tropics. They are caused by mites, lice and other blood-sucking insects. In resource-poor countries they are associated with considerable morbidity. Hitherto, EPSD are treated with insecticides with a neurotoxic mode of action. The efficacy of this treatment is variable, and the development and spread of resistant mites and lice is alarming. A new concept for treating EPSD is presented which is based on the topical application of dimeticones, silicone oils of low viscosity which rapidly kill insects and mites by a physical mode of action. They creep into the respiratory system and block oxygen supply. The physical mode of action makes the development of resistant parasite strains very unlikely. Due to their safety and efficacy, dimeticones are promising candidates for population-based intervention programmes targeted against EPSD in resource-poor settings.

  6. Characterization of the mode of action of a potent dengue virus capsid inhibitor.

    Science.gov (United States)

    Scaturro, Pietro; Trist, Iuni Margaret Laura; Paul, David; Kumar, Anil; Acosta, Eliana G; Byrd, Chelsea M; Jordan, Robert; Brancale, Andrea; Bartenschlager, Ralf

    2014-10-01

    Dengue viruses (DV) represent a significant global health burden, with up to 400 million infections every year and around 500,000 infected individuals developing life-threatening disease. In spite of attempts to develop vaccine candidates and antiviral drugs, there is a lack of approved therapeutics for the treatment of DV infection. We have previously reported the identification of ST-148, a small-molecule inhibitor exhibiting broad and potent antiviral activity against DV in vitro and in vivo (C. M. Byrd et al., Antimicrob. Agents Chemother. 57:15-25, 2013, doi:10 .1128/AAC.01429-12). In the present study, we investigated the mode of action of this promising compound by using a combination of biochemical, virological, and imaging-based techniques. We confirmed that ST-148 targets the capsid protein and obtained evidence of bimodal antiviral activity affecting both assembly/release and entry of infectious DV particles. Importantly, by using a robust bioluminescence resonance energy transfer-based assay, we observed an ST-148-dependent increase of capsid self-interaction. These results were corroborated by molecular modeling studies that also revealed a plausible model for compound binding to capsid protein and inhibition by a distinct resistance mutation. These results suggest that ST-148-enhanced capsid protein self-interaction perturbs assembly and disassembly of DV nucleocapsids, probably by inducing structural rigidity. Thus, as previously reported for other enveloped viruses, stabilization of capsid protein structure is an attractive therapeutic concept that also is applicable to flaviviruses. Dengue viruses are arthropod-borne viruses representing a significant global health burden. They infect up to 400 million people and are endemic to subtropical and tropical areas of the world. Currently, there are neither vaccines nor approved therapeutics for the prophylaxis or treatment of DV infections, respectively. This study reports the characterization of the

  7. Duration of activity and mode of action of modafinil: Studies on sleep and wakefulness in humans.

    Science.gov (United States)

    Turner, C; Belyavin, A J; Nicholson, A N

    2014-07-01

    The duration of activity of modafinil was investigated in healthy male volunteers in two double-blind crossover studies. Mode of action was explored using a statistical model concerned with the relationship between total sleep duration and that of rapid eye movement (REM) sleep. Nocturnal sleep (23:00-07:00) followed by next-day performance (09:00-17:00) was studied in 12 subjects administered 100, 200, 300 mg modafinil and placebo, 0.5 h before bedtime. Performance overnight (19:00-08:45) followed by sleep (09:15-15:15) was studied in nine subjects administered 100, 200, 300, 400 mg modafinil, 300 mg caffeine and placebo at 22:15. Modafinil dose-dependently reduced sleep duration (nocturnal: 200 mg, pmodafinil during overnight work varied with dose (200 mg>100 mg; 300, 400 mg>200, 100 mg, caffeine). However, in the study of next-day performance, the enhancement was attenuated at the highest dose (300 mg) by the greater disturbance of prior sleep. These findings indicate that modafinil has a long duration of action, with alerting properties arising predominantly from dopaminergic activity. © The Author(s) 2013.

  8. Modes of action for biological control of Botrytis cinerea by antagonistic bacteria

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    Rana HAIDAR

    2017-01-01

    Full Text Available The role of beneficial bacteria in biocontrol of plant diseases, particularly those caused by the necrotrophic fungus Botrytis cinerea, has been investigated by testing many bacteria under laboratory and field conditions. Bacteria may protect plants against B. cinerea by direct antagonistic interactions between biocontrol agents and this pathogen, as well as indirect effects through the induction of host resistance. This review focuses on various bacteria that act as biological control agents (BCAs of B. cinerea and their associated mechanisms. The modes of action (MoAs include: i synthesis of anti-fungal metabolites, such as antibiotics, cell wall-degrading enzymes and volatile organic compounds (VOCs; ii competition for nutrients and/or a niche; and iii induction of host resistance. The challenge for development of BCAs is to reduce the variability of efficiency and to prove persistence under a large range of conditions. We discuss the advantages and drawbacks of MoA for future applications of bacteria in the field and in post-harvest storage, as well as combination of different MoAs as a strategy to achieve a more regular efficacy.

  9. Discovery and mode of action of afoxolaner, a new isoxazoline parasiticide for dogs.

    Science.gov (United States)

    Shoop, Wesley L; Hartline, Eric J; Gould, Brandon R; Waddell, Molly E; McDowell, Richard G; Kinney, John B; Lahm, George P; Long, Jeffrey K; Xu, Ming; Wagerle, Ty; Jones, Gail S; Dietrich, Robert F; Cordova, Daniel; Schroeder, Mark E; Rhoades, Daniel F; Benner, Eric A; Confalone, Pat N

    2014-04-02

    Afoxolaner is an isoxazoline compound characterized by a good safety profile and extended effectiveness against fleas and ticks on dogs following a single oral administration. In vitro membrane feeding assay data and in vivo pharmacokinetic studies in dogs established an afoxolaner blood concentration of 0.1-0.2 μg/ml to be effective against both fleas (Ctenocephalides felis) and ticks (Dermacentor variabilis). Pharmacokinetic profiles in dogs following a 2.5mg/kg oral dosage demonstrated uniform and predictable afoxolaner plasma concentrations above threshold levels required for efficacy for more than one month. Dose ranging and a 5-month multi-dose experimental study in dogs, established that the 2.5mg/kg oral dosage was highly effective against fleas and ticks, and produced predictable and reproducible pharmacokinetics following repeated dosing. Mode of action studies showed that afoxolaner blocked native and expressed insect GABA-gated chloride channels with nanomolar potency. Afoxolaner has comparable potency between wild type channels and channels possessing the A302S (resistance-to-dieldrin) mutation. Lack of cyclodiene cross-resistance for afoxolaner was confirmed in comparative Drosophila toxicity studies, and it is concluded that afoxolaner blocked GABA-gated chloride channels via a site distinct from the cyclodienes. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Proteomic and metallomic strategies for understanding the mode of action of anticancer metallodrugs.

    Science.gov (United States)

    Gabbiani, Chiara; Magherini, Francesca; Modesti, Alessandra; Messori, Luigi

    2010-05-01

    Since the discovery of cisplatin and its introduction in the clinics, metal compounds have been intensely investigated in view of their possible application in cancer therapy. In this frame, a deeper understanding of their mode of action, still rather obscure, might turn crucial for the design and the obtainment of new and better anticancer agents. Due to the extreme complexity of the biological systems, it is now widely accepted that innovative and information-rich methods are absolutely needed to afford such a goal. Recently, both proteomic and metallomic strategies were successfully implemented for the elucidation of specific mechanistic features of anticancer metallodrugs within an innovative "Systems Biology" perspective. Particular attention was paid to the following issues: i) proteomic studies of the molecular basis of platinum resistance; ii) proteomic analysis of cellular responses to cytotoxic metallodrugs; iii) metallomic studies of the transformation and fate of metallodrugs in cellular systems. Notably, those pioneering studies, that are reviewed here, allowed a significant progress in the understanding of the molecular mechanisms of metal based drugs at the cellular level. A further extension of those studies and a closer integration of proteomic and metallomic strategies and technologies might realistically lead to rapid and significant advancements in the mechanistic knowledge of anticancer metallodrugs.

  11. Antifungal modes of action of tea tree oil and its two characteristic components against Botrytis cinerea.

    Science.gov (United States)

    Yu, D; Wang, J; Shao, X; Xu, F; Wang, H

    2015-11-01

    The essential oil of Melaleuca alternifolia (tea tree) has been evaluated as a potential eco-friendly antifungal agent against Botrytis cinerea. In this study, we investigated the antifungal activity and mode of action of tea tree oil (TTO) and its components against B. cinerea. Of the components we tested in contact phase, terpinen-4-ol had the highest antifungal activity, followed by TTO, α-terpineol, terpinolene, then 1,8-cineole. As one of characteristic components of TTO, terpinen-4-ol treatment led to pronounced alterations in mycelial morphology, cellular ultrastructure, membrane permeability under scanning electron microscope, transmission electron microscope and fluorescent microscope, and also reduced the ergosterol content of fungi. As another characteristic component, 1,8-cineole caused serious intracellular damage but only slightly affected B. cinerea otherwise. When terpinen-4-ol and 1,8-cineole were used together, the synergistic antifungal activity was significantly higher than either component by itself. The results of our study confirmed that terpinen-4-ol and 1,8-cineole act mainly on the cell membranes and organelles of B. cinerea, respectively, and when combined are similar to TTO in antifungal activity due to their differences. Understanding the mechanism of terpinen-4-ol and 1,8-cineole antifungal action to B. cinerea is helpful for investigation on their synergistic effect and explaining antifungal action modes of TTO. © 2015 The Society for Applied Microbiology.

  12. Coral snake venoms: mode of action and pathophysiology of experimental envenomation

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    Oswald Vital Brazil

    1987-06-01

    Full Text Available Coral snakes, the New World Elapidae, are included in the genera Micniroides and Micrurus. The genus Mlcrurus comprises nearly all coral snake species and those which are responsible for human snake-bite accidents. The following generalizations concerning the effects induced by their venoms, and their venom-properties can be made. Coral snake venoms are neurotoxic, producing loss of muscle strenght and death by respiratory paralysis. Local edema and necrosis are not induced nor blood coagulation or hemorrhages. Proteolysis activity is absent or of very low grade. They display phospholipase A2 activity. Nephrotoxic effects are not evoked. The main toxins from elapid venoms are postsynaptic and presynaptic neurotoxins and cardiotoxins. Phospholipases A2 endowed with myonecrotic or cardiotoxin-like properties are important toxic components from some elapid venoms. The mode of action of Micrurus frontalis, M. lemniscatus, M. corallinus and M. fulvius venoms has been investigated in isolated muscle preparations and is here discussed. It is shown that while M. frontalis and M. lemniscatus venoms must contain only neurotoxins that act at the cholinergic end-plate receptor (postsynaptic neurotoxins, M. corallinus venom also inhibits evoked acetylcholine release by the motor nerve endings (presynaptic neurotoxin-like effect and M. fulvius induces muscle fiber membrane depolarization (cardiotoxin-like effect. The effects produced by M. corallinus and M. fulvius venoms in vivo in dogs and M. frontalis venom in dogs and monkeys are also reported.

  13. The mode of action of juvenile hormone and ecdysone: towards an epi-endocrinological paradigm?

    Science.gov (United States)

    De Loof, Arnold; Boerjan, Bart; Ernst, Ulrich R; Schoofs, Liliane

    2013-07-01

    In some insect species, two sites of juvenile hormone (JH) synthesis have been reported: the very well documented corpora allata that secrete JH for "general use", and the reproductive system, in particular the male accessory glands, in which the function of the sometimes huge amounts of JH (e.g. in Hyalophora cecropia) remains to be clarified. A recent finding in Schistocerca gregaria, namely that suppression of the ecdysteroid peak preceding a molt by RNAi of the Halloween genes spook, phantom and shade does not impede normal molting, challenges the (never experimentally proven) classical concept that such a peak is causally linked to a molt. Recent developments in epigenetic control of gene expression in both the honey bee and in locusts suggest that, in addition to the classical scheme of hormone-receptor (membrane- and/or nuclear) mode of action, there may be a third way. Upon combining these and other orphan data that do not fit in the commonly accepted textbook schemes, we here advance the working hypothesis that both JH and ecdysone might be important but overlooked players in epigenetic control of gene expression, in particular at extreme concentrations (peak values or total absence). In this review, we put forward how epi-endocrinology can complement classical arthropod endocrinology. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Toward an understanding of the mode of action of fluoroquinolone drugs

    Science.gov (United States)

    Neugebauer, U.; Schmid, U.; Baumann, K.; Holzgrabe, U.; Schmitt, M.; Popp, J.

    2007-07-01

    Fluoroquinolones are important antibacterial drugs. They were found to interfere with the gyrase-DNA complex which causes cell death. However, the detailed mode of action on a molecular level is so far not understood. In this contribution Raman spectroscopy is chosen as a non-invasive technique to first characterize the individual involved components: fluoroquinolone drugs, and the biological targets DNA and gyrase; and second to study the influence of the fluoroquinolones on bacteria in in-vivo experiments. The use of UV resonance Raman spectroscopy with excitation at 244 nm allows the investigation of the drugs and the biological targets in aqueous solution at biological low concentrations (a few μM). Raman bands associated with the action of the enzyme gyrase could be identified in in-vitro mixing experiments. In-vivo experiments with bacteria experiencing varying drug concentrations revealed changes in the vibrational bands of the protein and DNA components within the bacterial cell caused by the action of the drug. Due to the complexity of the bacterial spectra advanced multivariate statistics in combination with variable selection methods proved to be useful in the data analysis.

  15. Activity and mode of action against fungal phytopathogens of bovine lactoferricin-derived peptides.

    Science.gov (United States)

    Muñoz, A; Marcos, J F

    2006-12-01

    To evaluate the activity against fungal phytopathogens of two synthetic peptides derived from the protein bovine lactoferricin: the antibacterial active core of six amino acid residues (LfcinB(20-25)) and an extension of 15 amino acids (LfcinB(17-31)). In vitro activity against fungal pathogens was determined and compared with that against model micro-organisms. Activity was demonstrated against fungi of agronomic relevance. Distinct antimicrobial properties in vitro were found for the two peptides. LfcinB(17-31) had growth inhibitory activity higher than LfcinB(20-25). However, LfcinB(17-31) was not fungicidal to quiescent conidia of Penicillium digitatum at the concentrations assayed, while LfcinB(20-25) killed conidia more efficiently. Microscopical observations showed that the mycelium of P. digitatum treated with LfcinB(17-31) developed alterations of growth, sporulation and chitin deposition, and permeation of hyphal cells. In experimental inoculations of mandarins, both peptides showed limited protective effect against the disease caused by P. digitatum. LfcinB(20-25) and LfcinB(17-31) peptides were shown to have antimicrobial activity against plant pathogenic filamentous fungi, with distinct properties and mode of action. LfcinB(20-25) and LfcinB(17-31) peptides offer novel alternatives to develop resistant plants by molecular breeding.

  16. TAXONOMICAL POSITION AND DISTRIBUTION OF BUSCHIA LATERIFLORA (DC. OVCZ. (RANUNCULACEAE JUSS. SPECIES IN THE BESSARABIA

    Directory of Open Access Journals (Sweden)

    CANTEMIR VALENTINA

    2011-12-01

    Full Text Available Having the target of taxonomic concretization the Ranunculus L. and Buschia (DC. Ovcz. genera from Bessarabia flora, the Herbarium specimens of Botanical Garden Academy of Sciences, and Moldova State University were investigated and analyzed. Research results attest the priority concept of Ranunculus L. genus and the presence of Buschia lateriflora (DC. Ovcz. species in native flora. Revealing a new habitat for Buschia lateriflora species complete the species area within South-East Europe limits. Morphologic distinctive criteria of studied genus are given.

  17. Metabolic responses of Eisenia fetida after sub-lethal exposure to organic contaminants with different toxic modes of action

    Energy Technology Data Exchange (ETDEWEB)

    McKelvie, Jennifer R.; Wolfe, David M.; Celejewski, Magda A. [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, ON M1C 1A4 (Canada); Alaee, Mehran [Environment Canada, 867 Lakeshore Rd., P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Simpson, Andre J. [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, ON M1C 1A4 (Canada); Simpson, Myrna J., E-mail: myrna.simpson@utoronto.ca [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, ON M1C 1A4 (Canada)

    2011-12-15

    Nuclear magnetic resonance (NMR) - based metabolomics has the potential to identify toxic responses of contaminants within a mixture in contaminated soil. This study evaluated the metabolic response of Eisenia fetida after exposure to an array of organic compounds to determine whether contaminant-specific responses could be identified. The compounds investigated in contact tests included: two pesticides (carbaryl and chlorpyrifos), three pharmaceuticals (carbamazephine, estrone and caffeine), two persistent organohalogens (Aroclor 1254 and PBDE 209) and two industrial compounds (nonylphenol and dimethyl phthalate). Control and contaminant-exposed metabolic profiles were distinguished using principal component analysis and potential contaminant-specific biomarkers of exposure were found for several contaminants. These results suggest that NMR-based metabolomics offers considerable promise for differentiating between the different toxic modes of action (MOA) associated with sub-lethal toxicity to earthworms. - Highlights: > NMR-based earthworm metabolomic analysis of the toxic mode of action of various environmental contaminants. > Organic chemicals with different toxic modes of action resulted in varied metabolomic responses for E. fetida. > NMR-based metabolomics differentiates between the different modes of action associated with sub-lethal toxicity. - {sup 1}H NMR metabolomics was used to identify potential biomarkers of organic contaminant exposure in Eisenia fetida earthworms.

  18. A Comprehensive Survey of Pelagic Megafauna: Their Distribution, Densities, and Taxonomic Richness in the Tropical Southwest Indian Ocean

    Directory of Open Access Journals (Sweden)

    Sophie Laran

    2017-05-01

    Full Text Available The distribution and density of pelagic megafauna (marine mammals, seabirds, elasmobranches, and sea turtles are important indicators of marine biodiversity, reflecting the condition of the underlying ecosystems. A dedicated aerial survey was conducted in the tropical Southwest Indian Ocean to map their distribution, the taxonomic diversity, and to estimate their densities to serve as a baseline for the area. This large survey across three ecological sub-regions revealed contrasting spatial distributions: maps of taxonomic richness of marine mammals and seabirds revealed different “hotspots” in the area. Densities were estimated for eight cetacean taxa with small and large Delphininae, or small Globicephalinae dominating, and for seven seabird taxa, with terns and noddies dominating. At the community level, the Southwest Indian Ocean megafauna was structured by the marine environment with strong differences between the Mozambique Channel and the Mascarene Islands, or between shelf and slope/oceanic habitats. Our results illustrate how multi-taxa aerial surveys are relevant and cost-effective monitoring tools for marine megafauna, allowing a community-wide approach.

  19. Targeted Phenotypic Screening in Plasmodium falciparum and Toxoplasma gondii Reveals Novel Modes of Action of Medicines for Malaria Venture Malaria Box Molecules.

    Science.gov (United States)

    Subramanian, Gowtham; Belekar, Meenakshi A; Shukla, Anurag; Tong, Jie Xin; Sinha, Ameya; Chu, Trang T T; Kulkarni, Akshay S; Preiser, Peter R; Reddy, D Srinivasa; Tan, Kevin S W; Shanmugam, Dhanasekaran; Chandramohanadas, Rajesh

    2018-01-01

    (human malaria) and Toxoplasma gondii (human and animal toxoplasmosis). Widespread resistance to current antimalarials and the lack of a commercial vaccine necessitate novel pharmacological interventions with distinct modes of action against malaria. For toxoplasmosis, new drugs to effectively eliminate tissue-dwelling latent cysts of the parasite are needed. The Malaria Box antimalarial collection, managed and distributed by the Medicines for Malaria Venture, includes molecules of novel chemical classes with proven antimalarial efficacy. Using targeted phenotypic assays of P. falciparum and T. gondii , we have identified a subset of the Malaria Box molecules as potent inhibitors of plastid segregation and parasite invasion and egress, thereby providing early insights into their probable mode of action. Five molecules that inhibit the egress of both parasites have been identified for further mechanistic studies. Thus, the approach we have used to identify novel molecules with defined modes of action in multiple parasites can expedite the development of pan-active antiparasitic agents.

  20. Mode of action of the positive modulator PNU-120596 on α7 nicotinic acetylcholine receptors.

    Science.gov (United States)

    Szabo, Anett K; Pesti, Krisztina; Mike, Arpad; Vizi, E Sylvester

    2014-06-01

    We investigated the mode of action of PNU-120596, a type II positive allosteric modulator of the rat α7 nicotinic acetylcholine receptor expressed by GH4C1 cells, using patch-clamp and fast solution exchange. We made two important observations: first, while PNU-120596 rapidly associated to desensitized receptors, it had at least hundredfold lower affinity to resting conformation, therefore at 10 μM concentration it dissociated from resting receptors; and second, binding of PNU-120596 slowed down dissociation of choline molecules from the receptor radically. We propose that when agonist concentration is transiently elevated in the continuous presence of the modulator (as upon the neuronal release of acetylcholine in a modulator-treated animal) these two elements together cause occurrence of a cycle of events: Binding of the modulator is limited in the absence of the agonist. When the agonist is released, it binds to the receptor, and induces desensitization, thereby enabling modulator binding. Modulator binding in turn traps the agonist within its binding site for a prolonged period of time. Once the agonist finally dissociated, the modulator can also dissociate without re-binding, and the receptor assumes its original resting conformation. In kinetic simulations this "trapped agonist cycle" mechanism did not require that the orthosteric and allosteric ligands symmetrically modify each other's affinity, only the modulator must decrease agonist accessibility, and the agonist must induce a conformation that is accessible to the modulator. This mechanism effectively prolongs and amplifies the effect of the agonist. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Neurotoxicity and mode of action of N, N-diethyl-meta-toluamide (DEET.

    Directory of Open Access Journals (Sweden)

    Daniel R Swale

    Full Text Available Recent studies suggest that N, N-diethyl-meta-toluamide (DEET is an acetylcholinesterase inhibitor and that this action may result in neurotoxicity and pose a risk to humans from its use as an insect repellent. We investigated the mode of action of DEET neurotoxicity in order to define the specific neuronal targets related to its acute toxicity in insects and mammals. Although toxic to mosquitoes (LD50 ca. 1.5 µg/mg, DEET was a poor acetylcholinesterase inhibitor (<10% inhibition, even at a concentration of 10 mM. IC50 values for DEET against Drosophila melanogaster, Musca domestica, and human acetylcholinesterases were 6-12 mM. Neurophysiological recordings showed that DEET had excitatory effects on the housefly larval central nervous system (EC50: 120 µM, but was over 300-fold less potent than propoxur, a standard anticholinesterase insecticide. Phentolamine, an octopamine receptor antagonist, completely blocked the central neuroexcitation by DEET and octopamine, but was essentially ineffective against hyperexcitation by propoxur and 4-aminopyridine, a potassium channel blocker. DEET was found to illuminate the firefly light organ, a tissue utilizing octopamine as the principal neurotransmitter. Additionally, DEET was shown to increase internal free calcium via the octopamine receptors of Sf21 cells, an effect blocked by phentolamine. DEET also blocked Na(+ and K(+ channels in patch clamped rat cortical neurons, with IC50 values in the micromolar range. These findings suggest DEET is likely targeting octopaminergic synapses to induce neuroexcitation and toxicity in insects, while acetylcholinesterase in both insects and mammals has low (mM sensitivity to DEET. The ion channel blocking action of DEET in neurons may contribute to the numbness experienced after inadvertent application to the lips or mouth of humans.

  2. Pleuromutilins: Potent Drugs for Resistant Bugs-Mode of Action and Resistance.

    Science.gov (United States)

    Paukner, Susanne; Riedl, Rosemarie

    2017-01-03

    use in veterinary medicine. This review focuses on the structural characteristics, mode of action, antibacterial activity, and resistance development of this potent and novel antibacterial class for systemic use in humans. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  3. Mode of action of Cr(VI) in immunocytes of earthworms: Implications for animal health.

    Science.gov (United States)

    Sforzini, Susanna; Moore, Michael N; Mou, Zhuofan; Boeri, Marta; Banni, Mohamed; Viarengo, Aldo

    2017-04-01

    Chromium (Cr) is one of the major and most detrimental pollutant, widely present in the environment as a result of several anthropogenic activities. In mammalian cells, Cr(VI) is known to enhance reactive oxygen species (ROS) production and to cause toxic and genotoxic effects. Less commonly investigated are the effects and mode of action of this contaminant in invertebrates, particularly in soil organisms. In this work, earthworms of the species Eisenia andrei were exposed for 1 and 3 days to various sublethal concentrations of Cr(VI) (2, 15, 30µgmL -1 ) using the paper contact toxicity test. In amoeboid leukocytes we investigated intracellular ROS and lipoperoxide production, oxidative DNA damage, and the effects on different cell functions. The analysis of the results shows that Cr(VI) triggered severe adverse reactions; the first events were an increase of intracellular ROS levels, generating in the cells oxidative stress conditions leading to membrane lipid peroxidation and oxidative DNA damage. Lysosomes showed relevant changes such as a strong membrane destabilization, which was accompanied by an increased catabolism of cytoplasmic proteins and accumulation of lipofuscin. With an increase in the dose and/or time of exposure, the physiological status of intracellular organelles (such as lysosomes, nucleus and mitochondria) showed further impairment and amoebocyte immune functions were adversely affected, as shown by the decrease of the phagocytic activity. By mapping the responses of the different parameters evaluated, diagnostic of (oxidative) stress events, against lysosomal membrane stability, a "health status" indicator (able to describe the stress syndrome from its early phase to pathology), we have shown that this biomarker is suitable as a prognostic test for health of earthworms. This is viewed as a crucial step toward the derivation of explanatory frameworks for prediction of pollutant impact on animal health. Copyright © 2017. Published by

  4. Mode of Action of the Sesquiterpene Lactones Psilostachyin and Psilostachyin C on Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Valeria P Sülsen

    Full Text Available Trypanosoma cruzi is the causative agent of Chagas' disease, which is a major endemic disease in Latin America and is recognized by the WHO as one of the 17 neglected tropical diseases in the world. Psilostachyin and psilostachyin C, two sesquiterpene lactones isolated from Ambrosia spp., have been demonstrated to have trypanocidal activity. Considering both the potential therapeutic targets present in the parasite, and the several mechanisms of action proposed for sesquiterpene lactones, the aim of this work was to characterize the mode of action of psilostachyin and psilostachyin C on Trypanosoma cruzi and to identify the possible targets for these molecules. Psilostachyin and psilostachyin C were isolated from Ambrosia tenuifolia and Ambrosia scabra, respectively. Interaction of sesquiterpene lactones with hemin, the induction of oxidative stress, the inhibition of cruzipain and trypanothione reductase and their ability to inhibit sterol biosynthesis were evaluated. The induction of cell death by apoptosis was also evaluated by analyzing phosphatidylserine exposure detected using annexin-V/propidium iodide, decreased mitochondrial membrane potential, assessed with Rhodamine 123 and nuclear DNA fragmentation evaluated by the TUNEL assay. Both STLs were capable of interacting with hemin. Psilostachyin increased about 5 times the generation of reactive oxygen species in Trypanosoma cruzi after a 4h treatment, unlike psilostachyin C which induced an increase in reactive oxygen species levels of only 1.5 times. Only psilostachyin C was able to inhibit the biosynthesis of ergosterol, causing an accumulation of squalene. Both sesquiterpene lactones induced parasite death by apoptosis. Upon evaluating the combination of both compounds, and additive trypanocidal effect was observed. Despite their structural similarity, both sesquiterpene lactones exerted their anti-T. cruzi activity through interaction with different targets. Psilostachyin

  5. Mode of Action of the Sesquiterpene Lactones Psilostachyin and Psilostachyin C on Trypanosoma cruzi.

    Science.gov (United States)

    Sülsen, Valeria P; Puente, Vanesa; Papademetrio, Daniela; Batlle, Alcira; Martino, Virginia S; Frank, Fernanda M; Lombardo, María E

    2016-01-01

    Trypanosoma cruzi is the causative agent of Chagas' disease, which is a major endemic disease in Latin America and is recognized by the WHO as one of the 17 neglected tropical diseases in the world. Psilostachyin and psilostachyin C, two sesquiterpene lactones isolated from Ambrosia spp., have been demonstrated to have trypanocidal activity. Considering both the potential therapeutic targets present in the parasite, and the several mechanisms of action proposed for sesquiterpene lactones, the aim of this work was to characterize the mode of action of psilostachyin and psilostachyin C on Trypanosoma cruzi and to identify the possible targets for these molecules. Psilostachyin and psilostachyin C were isolated from Ambrosia tenuifolia and Ambrosia scabra, respectively. Interaction of sesquiterpene lactones with hemin, the induction of oxidative stress, the inhibition of cruzipain and trypanothione reductase and their ability to inhibit sterol biosynthesis were evaluated. The induction of cell death by apoptosis was also evaluated by analyzing phosphatidylserine exposure detected using annexin-V/propidium iodide, decreased mitochondrial membrane potential, assessed with Rhodamine 123 and nuclear DNA fragmentation evaluated by the TUNEL assay. Both STLs were capable of interacting with hemin. Psilostachyin increased about 5 times the generation of reactive oxygen species in Trypanosoma cruzi after a 4h treatment, unlike psilostachyin C which induced an increase in reactive oxygen species levels of only 1.5 times. Only psilostachyin C was able to inhibit the biosynthesis of ergosterol, causing an accumulation of squalene. Both sesquiterpene lactones induced parasite death by apoptosis. Upon evaluating the combination of both compounds, and additive trypanocidal effect was observed. Despite their structural similarity, both sesquiterpene lactones exerted their anti-T. cruzi activity through interaction with different targets. Psilostachyin accomplished its antiparasitic

  6. A tripartite mode of action approach for investigating the impact of aneugens on tubulin polymerization.

    Science.gov (United States)

    Stock, Valerie; Sutter, Andreas; Raschke, Marian; Queisser, Nina

    2018-04-01

    Chemical-induced disruption of the cellular microtubule network is one key mechanism of aneugenicity. Since recent data indicate that genotoxic effects of aneugens show nonlinear dose-response relationships, margins of safety can be derived with the ultimate goal to perform a risk assessment for the support of drug development. Furthermore, microtubule-interacting compounds are widely used for cancer treatment. While there is a need to support the risk assessment of tubulin-interacting chemicals using reliable mechanistic assays, no standard assays exist to date in regulatory genotoxicity testing for the distinction of aneugenic mechanisms. Recently reported methods exclusively rely on either biochemical, morphological, or cytometric endpoints. Since data requirements for the diverse fields of application of those assays differ strongly, the use of multiple assays for a correct classification of aneugens is ideal. We here report a tripartite mode of action approach comprising a cell-free biochemical polymerization assay and the cell-based methods cellular imaging and flow cytometry. The biochemical assay measures tubulin polymerization over time whereas the two cell-based assays quantify tubulin polymer mass. We herein show that the flow cytometric method yielded IC 50 values for tubulin destabilizers and EC 50 values for tubulin stabilizers as well as cell cycle information. In contrast, cellular imaging complemented these findings with characteristic morphological patterns. Biochemical analysis yielded kinetic information on tubulin polymerization. This multiplex approach is able to create holistic effect profiles which can be individually customized to the research question with regard to quality, quantity, usability, and economy. Environ. Mol. Mutagen. 59:188-201, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Proposed Mode of Action for Acrolein Respiratory Toxicity Associated with Inhaled Tobacco Smoke.

    Science.gov (United States)

    Yeager, R Philip; Kushman, Mary; Chemerynski, Susan; Weil, Roxana; Fu, Xin; White, Marcella; Callahan-Lyon, Priscilla; Rosenfeldt, Hans

    2016-06-01

    This article presents a mode of action (MOA) analysis that identifies key mechanisms in the respiratory toxicity of inhaled acrolein and proposes key acrolein-related toxic events resulting from the inhalation of tobacco smoke. Smoking causes chronic obstructive pulmonary disorder (COPD) and acrolein has been previously linked to the majority of smoking-induced noncancer respiratory toxicity. In contrast to previous MOA analyses for acrolein, this MOA focuses on the toxicity of acrolein in the lower respiratory system, reflecting the exposure that smokers experience upon tobacco smoke inhalation. The key mechanisms of acrolein toxicity identified in this proposed MOA include (1) acrolein chemical reactivity with proteins and other macromolecules of cells lining the respiratory tract, (2) cellular oxidative stress, including compromise of the important anti-oxidant glutathione, (3) chronic inflammation, (4) necrotic cell death leading to a feedback loop where necrosis-induced inflammation leads to more necrosis and oxidative damage and vice versa, (5) tissue remodeling and destruction, and (6) loss of lung elasticity and enlarged lung airspaces. From these mechanisms, the proposed MOA analysis identifies the key cellular processes in acrolein respiratory toxicity that consistently occur with the development of COPD: inflammation and necrosis in the middle and lower regions of the respiratory tract. Moreover, the acrolein exposures that occur as a result of smoking are well above exposures that induce both inflammation and necrosis in laboratory animals, highlighting the importance of the role of acrolein in smoking-related respiratory disease. Published by Oxford University Press on behalf of the Society of Toxicology 2016. This work is written by US Government employees and is in the public domain in the US.

  8. Studies on the mode of action of the antifungal hexapeptide PAF26.

    Science.gov (United States)

    Muñoz, Alberto; López-García, Belén; Marcos, Jose F

    2006-11-01

    The small antimicrobial peptide PAF26 (Ac-RKKWFW-NH(2)) has been identified by a combinatorial approach and shows preferential activity toward filamentous fungi. In this work, we investigated the mode of action and inhibitory effects of PAF26 on the fungus Penicillium digitatum. The dye Sytox Green was used to demonstrate that PAF26 induced cell permeation. However, microscopic observations showed that sub-MIC concentrations of PAF26 produced both alterations of hyphal morphology (such as altered polar growth and branching) and chitin deposition in areas of no detectable permeation. Analysis of dose-response curves of inhibition and permeation suggested that growth inhibition is not solely a consequence of permeation. In order to shed light on the mode of PAF26 action, its antifungal properties were compared with those of melittin, a well-known pore-forming peptide that kills through cytolysis. While the 50% inhibitory concentrations and MICs of the two peptides against P. digitatum mycelium were comparable, they differed markedly in their fungicidal activities toward conidia and their hemolytic activities toward human red blood cells. Kinetic studies showed that melittin quickly induced Penicillium cell permeation, while PAF26-induced Sytox Green uptake was significantly slower and less efficient. Therefore, the ultimate growth inhibition and morphological alterations induced by PAF26 for P. digitatum are not likely a result of conventional pore formation. Fluorescently labeled PAF26 was used to demonstrate its specific in vivo interaction and translocation inside germ tubes and hyphal cells, at concentrations as low as 0.3 muM (20 times below the MIC), at which no inhibitory, morphological, or permeation effects were observed. Interestingly, internalized PAF26 could bind to cellular RNAs, since in vitro nonspecific RNA binding activity of PAF26 was demonstrated by electrophoretic mobility shift assays. We propose that PAF26 is a short, de novo-designed penetratin

  9. Modes of Action, Resistance and Toxicity of Insecticides Targeting Nicotinic Acetylcholine Receptors.

    Science.gov (United States)

    Ihara, Makoto; Buckingham, Steven D; Matsuda, Kazuhiko; Sattelle, David B

    2017-01-01

    Nicotinic acetylcholine receptors (nAChRs) of insects play a key role in fast excitatory neurotransmission. Several classes of insecticides target insect nAChRs, which are composed of subunit members of a family of multiple subunit encoding genes. Alternative splicing and RNA A-to-I editing can add further to receptor diversity. Native and recombinant receptors have been explored as sites of insecticide action using radioligands, electrophysiology and site-directed mutagenesis. We have reviewed the properties of native and recombinant insect nAChRs, the challenges of functional recombinant insect nAChR expression, nAChR interactions with ligands acting at orthosteric and allosteric sites and in particular their interactions with insecticides. Actions on insect nAChRs of cartap, neonicotinoids, spinosyns, sulfoxamines, butenolides and mesoionic insecticides are reviewed and current knowledge of their modes of action are addressed. Mutations that add to our understanding of insecticide action and those leading to resistance are discussed. Co-crystallisation of neonicotinoids with the acetylcholine binding protein (AChBP), a surrogate for the nAChR ligand binding domain, has proved instructive. Toxicity issues relating to insecticides targeting nAChRs are also considered. An overview of insecticide classes targeting insect nAChRs has enhanced our understanding of these important receptors and their insecticide binding sites. However, the subunit composition of native nAChRs remains poorly understood and functional expression still presents difficulties. These topics together with improved understanding of the precise sites of insecticide actions on insect nAChRs will be the subject of future research. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Taxonomic Identity, Geographic Distribution, and Commercial Exploitation of the Culinary-Medicinal Mushroom Pleurotus nebrodensis (Basidiomycetes).

    Science.gov (United States)

    Venturella, Giuseppe; Zervakis, Georgios I; Polemis, Elias; Gargano, Maria Letizia

    2016-01-01

    An updated overview of the outcome of studies conducted on the culinary-medicinal mushroom Pleurotus nebrodensis is presented by placing emphasis on the clarification of the taxonomic identity of P. nebrodensis and other related taxa possessing entirely white to cream basidiomes, which grow in association with different plants of the family Apiaceae. Cultivation techniques, quality of the product sold and sales price, as well as nutritional and medicinal aspects are discussed. Taking also into consideration the high economic importance of P. nebrodensis, it is essential to proceed with the verification of the commercial strains currently available in the international market under the name of "P. nebrodensis" since it is very probable that many (or most) of them do not represent the real P. nebrodensis. TO confirm this hypothesis, an in silico analysis was conducted on a large of number of ITS1-5.8S-ITS2 rRNA sequences deposited in the National Center for Biotechnology Information database under the name P. nebrodensis. Results demonstrated that all "P nebrodensis" material examined from China (plus several sequences of no reported origin) corresponded to P. eryngii subsp. tuoliensis, with only 2 exceptions, which were grouped within P. eryngii sensu stricto. The real P. nebrodensis biological material from Italy and Greece is certified and is available upon request by the authors at the University of Palermo and the Agricultural University of Athens.

  11. An integrated approach for prospectively investigating a mode-of-action for rodent liver effects

    Energy Technology Data Exchange (ETDEWEB)

    LeBaron, Matthew J., E-mail: MJLeBaron@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Geter, David R., E-mail: dave.geter@gmail.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Rasoulpour, Reza J. [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Gollapudi, B. Bhaskar, E-mail: BBGollapudi@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Thomas, Johnson, E-mail: JThomas4@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Murray, Jennifer, E-mail: AMurray@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Kan, H. Lynn, E-mail: HLKan@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Wood, Amanda J., E-mail: AJWood@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Elcombe, Cliff, E-mail: CliffElcombe@cxrbiosciences.com [CXR Biosciences, 2 James Lindsay Place, Dundee Technopole, Dundee, DD1 5JJ, Scotland (United Kingdom); Vardy, Audrey, E-mail: audrey_vardy@europe.bd.com [CXR Biosciences, 2 James Lindsay Place, Dundee Technopole, Dundee, DD1 5JJ, Scotland (United Kingdom); McEwan, Jillian, E-mail: jillian.mcewan@rtmcewan.co.uk [CXR Biosciences, 2 James Lindsay Place, Dundee Technopole, Dundee, DD1 5JJ, Scotland (United Kingdom); Terry, Claire, E-mail: CTerry@dow.com [Dow AgroSciences, Abingdon, Oxfordshire (United Kingdom); Billington, Richard, E-mail: RBillington@dow.com [Dow AgroSciences, Abingdon, Oxfordshire (United Kingdom)

    2013-07-15

    Registration of new plant protection products (e.g., herbicide, insecticide, or fungicide) requires comprehensive mammalian toxicity evaluation including carcinogenicity studies in two species. The outcome of the carcinogenicity testing has a significant bearing on the overall human health risk assessment of the substance and, consequently, approved uses for different crops across geographies. In order to understand the relevance of a specific tumor finding to human health, a systematic, transparent, and hypothesis-driven mode of action (MoA) investigation is, appropriately, an expectation by the regulatory agencies. Here, we describe a novel approach of prospectively generating the MoA data by implementing additional end points to the standard guideline toxicity studies with sulfoxaflor, a molecule in development. This proactive MoA approach results in a more robust integration of molecular with apical end points while minimizing animal use. Sulfoxaflor, a molecule targeting sap-feeding insects, induced liver effects (increased liver weight due to hepatocellular hypertrophy) in an initial palatability probe study for selecting doses for subsequent repeat-dose dietary studies. This finding triggered the inclusion of dose-response investigations of the potential key events for rodent liver carcinogenesis, concurrent with the hazard assessment studies. As predicted, sulfoxaflor induced liver tumors in rats and mice in the bioassays. The MoA data available by the time of the carcinogenicity finding supported the conclusion that the carcinogenic potential of sulfoxaflor was due to CAR/PXR nuclear receptor activation with subsequent hepatocellular proliferation. This MoA was not considered to be relevant to humans as sulfoxaflor is unlikely to induce hepatocellular proliferation in humans and therefore would not be a human liver carcinogen. - Highlights: • We prospectively generated MoA data into standard guideline toxicity studies. • A proactive MoA approach

  12. Assessment of the mode of action for hexavalent chromium-induced lung cancer following inhalation exposures

    International Nuclear Information System (INIS)

    Proctor, Deborah M.; Suh, Mina; Campleman, Sharan L.; Thompson, Chad M.

    2014-01-01

    Highlights: • No published or well recognized MOA for Cr(VI)-induced lung tumors exists. • MOA analysis for Cr(VI)-induced lung cancer was conducted to inform risk assessment. • Cr(VI) epidemiologic, toxicokinetic, toxicological, mechanistic data were evaluated. • Weight of evidence does not support a mutagenic MOA for Cr(VI)-induced lung cancer. • Non-linear approaches should be considered for evaluating Cr(VI) lung cancer risk. - Abstract: Inhalation of hexavalent chromium [Cr(VI)] is associated with increased lung cancer risk among workers in several industries, most notably chromate production workers exposed to high concentrations of Cr(VI) (≥100 μg/m 3 ), for which clear exposure–response relationships and respiratory irritation and tissue damage have been reported. Data from this industry are used to assess lung cancer risk associated with environmental and current occupational exposures, occurring at concentrations that are significantly lower. There is considerable uncertainty in the low dose extrapolation of historical occupational epidemiology data to assess risk at current exposures because no published or well recognized mode of action (MOA) for Cr(VI)-induced lung tumors exists. We conducted a MOA analysis for Cr(VI)-induced lung cancer evaluating toxicokinetic and toxicological data in humans and rodents and mechanistic data to assess plausibility, dose–response, and temporal concordance for potential MOAs. Toxicokinetic data support that extracellular reduction of Cr(VI), which limits intracellular absorption of Cr(VI) and Cr(VI)-induced toxicity, can be overwhelmed at high exposure levels. In vivo genotoxicity and mutagenicity data are mostly negative and do not support a mutagenic MOA. Further, both chronic bioassays and the epidemiologic literature support that lung cancer occurs at exposures that cause tissue damage. Based on this MOA analysis, the overall weight of evidence supports a MOA involving deposition and accumulation

  13. An evaluation of the mode of action framework for mutagenic carcinogens case study: Cyclophosphamide.

    Science.gov (United States)

    McCarroll, Nancy; Keshava, Nagalakshmi; Cimino, Michael; Chu, Margaret; Dearfield, Kerry; Keshava, Channa; Kligerman, Andrew; Owen, Russell; Protzel, Alberto; Putzrath, Resha; Schoeny, Rita

    2008-03-01

    In response to the 2005 revised US Environmental Protection Agency (EPA) Cancer Guidelines, a Risk Assessment Forum's Technical Panel has devised a strategy in which genetic toxicology data combined with other information are assessed to determine whether a carcinogen operates through a mutagenic mode of action (MOA). This information is necessary for EPA to decide whether age-dependent adjustment factors (ADAFs) should be applied to the cancer risk assessment. A decision tree has been developed as a part of this approach and outlines the critical steps for analyzing a compound for carcinogenicity through a mutagenic MOA (e.g., data analysis, determination of mutagenicity in animals and in humans). Agents, showing mutagenicity in animals and humans, proceed through the Agency's framework analysis for MOAs. Cyclophosphamide (CP), an antineoplastic agent, which is carcinogenic in animals and humans and mutagenic in vitro and in vivo, was selected as a case study to illustrate how the framework analysis would be applied to prove that a carcinogen operates through a mutagenic MOA. Consistent positive results have been seen for mutagenic activity in numerous in vitro assays, in animals (mice, rats, and hamsters) and in humans. Accordingly, CP was processed through the framework analysis and key steps leading to tumor formation were identified as follows: metabolism of the parent compound to alkylating metabolites, DNA damage followed by induction of multiple adverse genetic events, cell proliferation, and bladder tumors. Genetic changes in rats (sister chromatid exchanges at 0.62 mg/kg) can commence within 30 min and in cancer patients, chromosome aberrations at 35 mg/kg are seen by 1 hr, well within the timeframe and tumorigenic dose range for early events. Supporting evidence is also found for cell proliferation, indicating that mutagenicity, associated with cytotoxicity, leads to a proliferative response, which occurs early (48 hr) in the process of tumor induction

  14. ‘Function-first’ Lead Discovery: Mode of Action Profiling of Natural Product Libraries Using Image-Based Screening

    Science.gov (United States)

    Schulze, Christopher J.; Bray, Walter M.; Woerhmann, Marcos H.; Stuart, Joshua; Lokey, R. Scott; Linington, Roger G.

    2013-01-01

    Summary Cytological profiling is a high-content image-based screening technology that provides insight into the mode of action (MOA) for test compounds by directly measuring hundreds of phenotypic cellular features. We have extended this recently reported technology to the mechanistic characterization of unknown natural products libraries for the direct prediction of compound MOAs at the primary screening stage. By analyzing a training set of commercial compounds of known mechanism and comparing these profiles to those obtained from natural product library members, we have successfully annotated extracts based on mode of action, dereplicated known compounds based on biological similarity to the training set, and identified and predicted the MOA of a family of new iron siderophores. Coupled with traditional analytical techniques, cytological profiling provides a new avenue for the creation of ‘function-first’ platforms for natural products discovery. PMID:23438757

  15. Mode of action of poly(vinylpyridine-N-oxide) in preventing silicosis: Effective scavenging of carbonate anion radical

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.; Czapski, G.; Heller, A. [Hebrew University of Jerusalem, Jerusalem (Israel). Dept. of Physical Chemistry

    2006-01-15

    Inhalation of quartz crystallites causes silicosis, a devastating lung disease afflicting miners, particularly coal and stone workers. Poly(vinylpyridine-N-oxide)s (PVPNOs) have been applied in the prevention and treatment of silicosis, but their mode of action has been obscure. Here, we show that PVPNOs do not react with peroxynitrite but scavenge exceptionally rapidly carbonate radicals, which are produced in the decomposition of ONOO- in bicarbonate solutions.

  16. Elucidation of the Mode of Action of a New Antibacterial Compound Active against Staphylococcus aureus and Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Evelien Gerits

    Full Text Available Nosocomial and community-acquired infections caused by multidrug resistant bacteria represent a major human health problem. Thus, there is an urgent need for the development of antibiotics with new modes of action. In this study, we investigated the antibacterial characteristics and mode of action of a new antimicrobial compound, SPI031 (N-alkylated 3, 6-dihalogenocarbazol 1-(sec-butylamino-3-(3,6-dichloro-9H-carbazol-9-ylpropan-2-ol, which was previously identified in our group. This compound exhibits broad-spectrum antibacterial activity, including activity against the human pathogens Staphylococcus aureus and Pseudomonas aeruginosa. We found that SPI031 has rapid bactericidal activity (7-log reduction within 30 min at 4x MIC and that the frequency of resistance development against SPI031 is low. To elucidate the mode of action of SPI031, we performed a macromolecular synthesis assay, which showed that SPI031 causes non-specific inhibition of macromolecular biosynthesis pathways. Liposome leakage and membrane permeability studies revealed that SPI031 rapidly exerts membrane damage, which is likely the primary cause of its antibacterial activity. These findings were supported by a mutational analysis of SPI031-resistant mutants, a transcriptome analysis and the identification of transposon mutants with altered sensitivity to the compound. In conclusion, our results show that SPI031 exerts its antimicrobial activity by causing membrane damage, making it an interesting starting point for the development of new antibacterial therapies.

  17. Taxonomic distribution of defensive alkaloids in Nearctic oribatid mites (Acari, Oribatida).

    Science.gov (United States)

    Saporito, Ralph A; Norton, Roy A; Garraffo, Martin H; Spande, Thomas F

    2015-11-01

    The opisthonotal (oil) glands of oribatid mites are the source of a wide diversity of taxon-specific defensive chemicals, and are likely the location for the more than 90 alkaloids recently identified in oribatids. Although originally recognized in temperate oribatid species, alkaloids have also been detected in related lineages of tropical oribatids. Many of these alkaloids are also present in a worldwide radiation of poison frogs, which are known to sequester these defensive chemicals from dietary arthropods, including oribatid mites. To date, most alkaloid records involve members of the superfamily Oripodoidea (Brachypylina), although few species have been examined and sampling of other taxonomic groups has been highly limited. Herein, we examined adults of more than 60 species of Nearctic oribatid mites, representing 46 genera and 33 families, for the presence of alkaloids. GC-MS analyses of whole body extracts led to the detection of 15 alkaloids, but collectively they occur only in members of the genera Scheloribates (Scheloribatidae) and Protokalumma (Parakalummidae). Most of these alkaloids have also been detected previously in the skin of poison frogs. All examined members of the oripodoid families Haplozetidae and Oribatulidae were alkaloid-free, and no mites outside the Oripodoidea contained alkaloids. Including previous studies, all sampled species of the cosmopolitan oripodoid families Scheloribatidae and Parakalummidae, and the related, mostly tropical families Mochlozetidae and Drymobatidae contain alkaloids. Our findings are consistent with a generalization that alkaloid presence is widespread, but not universal in Oripodoidea. Alkaloid presence in tropical, but not temperate members of some non-oripodoid taxa (in particular Galumnidae) deserves further study.

  18. Taxonomic minimalism.

    Science.gov (United States)

    Beattle, A J; Oliver, I

    1994-12-01

    Biological surveys are in increasing demand while taxonomic resources continue to decline. How much formal taxonomy is required to get the job done? The answer depends on the kind of job but it is possible that taxonomic minimalism, especially (1) the use of higher taxonomic ranks, (2) the use of morphospecies rather than species (as identified by Latin binomials), and (3) the involvement of taxonomic specialists only for training and verification, may offer advantages for biodiversity assessment, environmental monitoring and ecological research. As such, formal taxonomy remains central to the process of biological inventory and survey but resources may be allocated more efficiently. For example, if formal Identification is not required, resources may be concentrated on replication and increasing sample sizes. Taxonomic minimalism may also facilitate the inclusion in these activities of important but neglected groups, especially among the invertebrates, and perhaps even microorganisms. Copyright © 1994. Published by Elsevier Ltd.

  19. Evidence-based modeling of mode-of-action for functional ingredients influencing Alzheimer’s disease through neurotrophin pathway

    Directory of Open Access Journals (Sweden)

    Erfan Younesi

    2014-08-01

    Full Text Available Background: Brain-derived neurotrophic factor (BDNF is the most widely expressed member of the neurotrophin family in the human brain and is crucially involved in the development of neural circuits, modulation of synaptic plasticity, and regulation of cognitive functions, including learning and memory. Many studies have shown the association of altered BDNF levels with neurodegenerative and neuropsychiatric disorders. However, BDNF is not able to cross the blood-brain barrier and, thus, its delivery to the nervous system is a challenge. Therefore, functional diets with the ability to induce production of BDNF in the brain may offer an alternative route. The objective of this study was three-fold: first, to find out diets that are causally linked to the agonistic activity of BDNF in the neurotrophin signaling pathway; second and mainly, to investigate mode-of-action of these functional diets through systems-based mechanistic modeling in the context of Alzheimer’s disease; and third, to demonstrate the proof-of-concept application of systems biology methods, that are well established in the pharmaceutical sector, to the emerging field of functional food. Methods: In the first step, two cause-and-effect models of BDNF signaling in two states, i.e. normal state and Alzheimer’s disease state, were constructed using published knowledge in scientific literature and pathway databases. A “differential model analysis” between the two states was performed by which mechanistic mode-of-action of BDNF in neurotrophin signaling pathway could be explained with a high molecular resolution in both normal and disease states. The BDNF mode-of-action model was further validated using the “biomarkerguided validation” approach. In the second step, scientific evidence on the effect of various functional diets on BDNF levels and BDNF-related biological processes or outcomes was harvested from biomedical literature using a disease-specific semantic search

  20. Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites.

    Science.gov (United States)

    Simon-Delso, N; Amaral-Rogers, V; Belzunces, L P; Bonmatin, J M; Chagnon, M; Downs, C; Furlan, L; Gibbons, D W; Giorio, C; Girolami, V; Goulson, D; Kreutzweiser, D P; Krupke, C H; Liess, M; Long, E; McField, M; Mineau, P; Mitchell, E A D; Morrissey, C A; Noome, D A; Pisa, L; Settele, J; Stark, J D; Tapparo, A; Van Dyck, H; Van Praagh, J; Van der Sluijs, J P; Whitehorn, P R; Wiemers, M

    2015-01-01

    doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.

  1. Loveridge’s Angolan geckos, Afroedura karroica bogerti and Pachydactylus scutatus angolensis (Sauria, Gekkonidae: new distribution records, comments on type localities and taxonomic status

    Directory of Open Access Journals (Sweden)

    William R. Branch

    2017-03-01

    Full Text Available In 1944 Loveridge described two new geckos from Angola Afroedura karroica bogerti and Pachydactylus scutatus angolensis. The descriptions of both species have vague and confusing type localities and refinements are suggested based on early expedition reports historical accounts from the region and a review of cartographic material. Numerous new distribution records are reported for both species from expeditions undertaken from 1956–2016 by the authors or their colleagues. The taxonomic status of both species has changed but new material from diverse habitats altitudes and geological substrates indicates that further taxonomic adjustments are likely in order to reflect additional cryptic diversity.

  2. Taxonomic key for the genera of Elmidae (Coleoptera, Byrrhoidea occurring in Goiás State, Brazil, including new records and distributional notes

    Directory of Open Access Journals (Sweden)

    Felipe F. Barbosa

    2013-06-01

    Full Text Available A taxonomic key for the genera of Elmidae (Coleoptera, Byrrhoidea occurring in Goiás State, Brazil, including new records and distributional notes. Despite their great diversity and high abundance in Neotropical aquatic environments, the fauna of Elmidae remains practically unknown in some areas and even entire biomes in this region. In this work we bring, for the first time, faunistic data for the Elmidae of central Brazil. The aim of this work was to inventory the Elmidae fauna in central, southwestern and southeastern Goiás State, Brazil and to produce a taxonomic key, at genus level, for adults from the studied region. The taxonomic key presented herein offers means for the identification of all the 13 genera known to occur in Goiás, 11 of them being new records for the State. Moreover, the number of named species registered for Goiás increased from one to nine.

  3. Taxonomical and ecological characteristics of the desmids placoderms in reservoir: analyzing the spatial and temporal distribution

    Directory of Open Access Journals (Sweden)

    Sirlene Aparecida Felisberto

    2014-12-01

    Full Text Available AIM: This study aimed to evaluate the influence of river-dam axis and abiotic factors on the composition of Closteriaceae, Gonatozygaceae, Mesotaeniaceae and Peniaceae in a tropical reservoir METHODS: Water samples for physical, chemical and periphyton analysis were collected in April and August 2002 in different regions along the axis of the river-dam of Rosana Reservoir, River Basin Paranapanema. The substrates collected, always in the litoranea region, were petioles of Eichhornia azurea (Swartz Kunth. To examine the relationship of abiotic variables with reservoir zones and between the floristic composition of desmids, we used principal component analysis (PCA and canonical correspondence analysis (CCA RESULTS: The results of the PCA explained 81.3% of the total variability in the first two axes. In the first axis, the variables of conductivity, water temperature and the pH were related to the sampling regions of April with higher values, while for the month of August, nitrate, total phosphorus and dissolved oxygen showed higher values. We identified 20 taxa, distributed in the genera Closterium (14, Gonatozygon (4, Netrium (1 and Penium (1. Spatially, the higher taxa were recorded in the lacustrine region for both collection periods. The canonical correspondence analysis (CCA summarized 62.2% of total data variability of taxa in the first two axes, and in August, Closterium incurvum Brébisson, C. cornu Ehrenberg ex Ralfs and Gonatozygon monotaenium De Bary, were related to higher values of turbidity and nitrate to the lacustrine and intermediate regions CONCLUSION: Thus, the formation of groups was due to the regions along the longitudinal axis, then the seasonal period, which must be related to the low current velocity, the higher values of temperature and the water transparency, especially in late summer

  4. Classification, mode of action and production strategy of xylanase and its application for biofuel production from water hyacinth.

    Science.gov (United States)

    Uday, Uma Shankar Prasad; Choudhury, Payel; Bandyopadhyay, Tarun Kanti; Bhunia, Biswanath

    2016-01-01

    Xylanases are classified under glycoside hydrolase families which represent one of the largest groups of commercial enzymes. Depolymerizing xylan molecules into monomeric pentose units involves the synergistic action of mainly two key enzymes which are endo-β-xylanase and β-xylosidase. Xylanases are different with respect to their mode of action, substrate specificities, biochemical properties, 3D structure and are widely produced by a spectrum of bacteria and fungi. Currently, large scale production of xylanase can be produced through the application of genetic engineering tool which allow fast identification of novel xylanase genes and their genetic variations makes it an ideal enzymes. Due to depletion of fossil fuel, there is urgent need to find out environment friendly and sustainable energy sources. Therefore, utilisation of cheap lignocellulosic materials along with proper optimisation of process is most important for cost efficient ethanol production. Among, various types of lignocellulosic substances, water hyacinth, a noxious aquatic weed, has been found in many tropical. Therefore, the technological development for biofuel production from water hyacinth is becoming commercially worthwhile. In this review, the classification and mode of action of xylanase including genetic regulation and strategy for robust xylanase production have been critically discussed from recent reports. In addition various strategies for cost effective biofuel production from water hyacinth including chimeric proteins design has also been critically evaluated. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Accelerating early anti-tuberculosis drug discovery by creating mycobacterial indicator strains that predict mode of action

    KAUST Repository

    Boot, Maikel

    2018-04-13

    Due to the rise of drug resistant forms of tuberculosis there is an urgent need for novel antibiotics to effectively combat these cases and shorten treatment regimens. Recently, drug screens using whole cell analyses have been shown to be successful. However, current high-throughput screens focus mostly on stricto sensu life-death screening that give little qualitative information. In doing so, promising compound scaffolds or non-optimized compounds that fail to reach inhibitory concentrations are missed. To accelerate early TB drug discovery, we performed RNA sequencing on Mycobacterium tuberculosis and Mycobacterium marinum to map the stress responses that follow upon exposure to sub-inhibitory concentrations of antibiotics with known targets: ciprofloxacin, ethambutol, isoniazid, streptomycin and rifampicin. The resulting dataset comprises the first overview of transcriptional stress responses of mycobacteria to different antibiotics. We show that antibiotics can be distinguished based on their specific transcriptional stress fingerprint. Notably, this fingerprint was more distinctive in M. marinum. We decided to use this to our advantage and continue with this model organism. A selection of diverse antibiotic stress genes was used to construct stress reporters. In total, three functional reporters were constructed to respond to DNA damage, cell wall damage and ribosomal inhibition. Subsequently, these reporter strains were used to screen a small anti-TB compound library to predict the mode of action. In doing so, we could identify the putative mode of action for three novel compounds, which confirms our approach.

  6. Overview: Using Mode of Action and Life Stage Information to Evaluate the Human Relevance of Animal Toxicity Data

    Energy Technology Data Exchange (ETDEWEB)

    Seed, Jennifer; Carney, E W.; Corley, Rick A.; Crofton, Kevin M.; DeSesso, John M.; Foster, Paul M.; Kavlock, Robert; Kimmel, Gary; Klaunig, James E.; Meek, M E.; Preston, R J.; Slikker, William; Tabacova, Sonia; Williams, Gary M.; Wiltse, J; Zoeller, R T.; Fenner-Crisp, P; Patton, D E.

    2005-10-01

    A complete mode of action human relevance analysis--as distinct from mode of action (MOA) analysis alone--depends on robust information on the animal MOA, as well as systematic comparison of the animal data with corresponding information from humans. In November 2003, the International Life Sciences Institute's Risk Science Institute (ILSI RSI) published a 2-year study using animal and human MOA information to generate a four-part Human Relevance Framework (HRF) for systematic and transparent analysis of MOA data and information. Based mainly on non-DNA-reactive carcinogens, the HRF features a ''concordance'' analysis of MOA information from both animal and human sources, with a focus on determining the appropriate role for each MOA data set in human risk assessment. With MOA information increasingly available for risk assessment purposes, this article illustrates the further applicability of the HRF for reproductive, developmental, neurologic, and renal endpoints, as well as cancer. Based on qualitative and quantitative MOA considerations, the MOA/human relevance analysis also contributes to identifying data needs and issues essential for the dose-response and exposure assessment steps in the overall risk assessment.

  7. Inhibition of Listeria monocytogenes on Ready-to-Eat Meats Using Bacteriocin Mixtures Based on Mode-of-Action

    Directory of Open Access Journals (Sweden)

    Paul Priyesh Vijayakumar

    2017-03-01

    Full Text Available Bacteriocin-producing (Bac+ lactic acid bacteria (LAB comprising selected strains of Lactobacillus curvatus, Lactococcus lactis, Pediococcus acidilactici, and Enterococcus faecium and thailandicus were examined for inhibition of Listeria monocytogenes during hotdog challenge studies. The Bac+ strains, or their cell-free supernatants (CFS, were grouped according to mode-of-action (MOA as determined from prior studies. Making a mixture of as many MOAs as possible is a practical way to obtain a potent natural antimicrobial mixture to address L. monocytogenes contamination of RTE meat products (i.e., hotdogs. The heat resistance of the bacteriocins allowed the use of pasteurization to eliminate residual producer cells for use as post-process surface application or their inclusion into hotdog meat emulsion during cooking. The use of Bac+ LAB comprising 3× MOAs directly as co-inoculants on hotdogs was not effective at inhibiting L. monocytogenes. However, the use of multiple MOA Bac+ CFS mixtures in a variety of trials demonstrated the effectiveness of this approach by showing a >2-log decrease of L. monocytogenes in treatment samples and 6–7 log difference vs. controls. These data suggest that surface application of multiple mode-of-action bacteriocin mixtures can provide for an Alternative 2, and possibly Alternative 1, process category as specified by USDA-FSIS for control of L. monocytogenes on RTE meat products.

  8. MOSAIC: a chemical-genetic interaction data repository and web resource for exploring chemical modes of action.

    Science.gov (United States)

    Nelson, Justin; Simpkins, Scott W; Safizadeh, Hamid; Li, Sheena C; Piotrowski, Jeff S; Hirano, Hiroyuki; Yashiroda, Yoko; Osada, Hiroyuki; Yoshida, Minoru; Boone, Charles; Myers, Chad L

    2018-04-01

    Chemical-genomic approaches that map interactions between small molecules and genetic perturbations offer a promising strategy for functional annotation of uncharacterized bioactive compounds. We recently developed a new high-throughput platform for mapping chemical-genetic (CG) interactions in yeast that can be scaled to screen large compound collections, and we applied this system to generate CG interaction profiles for more than 13 000 compounds. When integrated with the existing global yeast genetic interaction network, CG interaction profiles can enable mode-of-action prediction for previously uncharacterized compounds as well as discover unexpected secondary effects for known drugs. To facilitate future analysis of these valuable data, we developed a public database and web interface named MOSAIC. The website provides a convenient interface for querying compounds, bioprocesses (Gene Ontology terms) and genes for CG information including direct CG interactions, bioprocesses and gene-level target predictions. MOSAIC also provides access to chemical structure information of screened molecules, chemical-genomic profiles and the ability to search for compounds sharing structural and functional similarity. This resource will be of interest to chemical biologists for discovering new small molecule probes with specific modes-of-action as well as computational biologists interested in analysing CG interaction networks. MOSAIC is available at http://mosaic.cs.umn.edu. hisyo@riken.jp, yoshidam@riken.jp, charlie.boone@utoronto.ca or chadm@umn.edu. Supplementary data are available at Bioinformatics online.

  9. Inhibition of voltage-gated calcium channels as common mode of action for (mixtures of) distinct classes of insecticides.

    Science.gov (United States)

    Meijer, Marieke; Dingemans, Milou M L; van den Berg, Martin; Westerink, Remco H S

    2014-09-01

    Humans are exposed to distinct structural classes of insecticides with different neurotoxic modes of action. Because calcium homeostasis is essential for proper neuronal function and development, we investigated the effects of insecticides from different classes (pyrethroid: (α-)cypermethrin; organophosphate: chlorpyrifos; organochlorine: endosulfan; neonicotinoid: imidacloprid) and mixtures thereof on the intracellular calcium concentration ([Ca(2+)]i). Effects of acute (20 min) exposure to (mixtures of) insecticides on basal and depolarization-evoked [Ca(2+)]i were studied in vitro with Fura-2-loaded PC12 cells and high resolution single-cell fluorescence microscopy. The data demonstrate that cypermethrin, α-cypermethrin, endosulfan, and chlorpyrifos concentration-dependently decreased depolarization-evoked [Ca(2+)]i, with 50% (IC50) at 78nM, 239nM, 250nM, and 899nM, respectively. Additionally, acute exposure to chlorpyrifos or endosulfan (10μM) induced a modest increase in basal [Ca(2+)]i, amounting to 68 ± 8nM and 53 ± 8nM, respectively. Imidacloprid did not disturb basal or depolarization-evoked [Ca(2+)]i at 10μM. Following exposure to binary mixtures, effects on depolarization-evoked [Ca(2+)]i were within the expected effect additivity range, whereas the effect of the tertiary mixture was less than this expected additivity effect range. These results demonstrate that different types of insecticides inhibit depolarization-evoked [Ca(2+)]i in PC12 cells by inhibiting voltage-gated calcium channels (VGCCs) in vitro at concentrations comparable with human occupational exposure levels. Moreover, the effective concentrations in this study are below those for earlier described modes of action. Because inhibition of VGCCs appears to be a common and potentially additive mode of action of several classes of insecticides, this target should be considered in neurotoxicity risk assessment studies. © The Author 2014. Published by Oxford University Press on behalf

  10. Antibacterial mode of action of 1,8-dihydroxy-anthraquinone from Porphyra haitanensis against Staphylococcus aureus.

    Science.gov (United States)

    Wei, Yuxi; Liu, Qi; Yu, Jia; Feng, Qiang; Zhao, Ling; Song, Huiping; Wang, Wenxiu

    2015-01-01

    As one kind of anthraquinone dihydroxy derivatives, 1,8-dihydroxy-anthraquinone (Dan) with strong antibacterial activity against Staphylococcus aureus was first isolated from Porphyra haitanensis. Here, we report on the investigation of the antibacterial mode of action of Dan on the Gram-positive bacterium S. aureus. The results show that Dan strongly inhibited cell growth at logarithmic phase. In this study, the antibacterial activity of Dan was analysed by using phosphorus standard solution, p-nitrophenyl phosphate, o-nitrophenyl-β-D-galactopyanoside, scanning electron microscopy and transmission electron microscopy. The results suggested that the antibacterial activity of Dan is due to its interaction with the cell wall and cell membrane, by which it increases the permeability of the cell envelope and leads to the leakage of cytoplasm and the deconstruction of cell. This study indicates that Dan as a natural product in seaweeds deserves further investigation for applications as an antibacterial bioactive substance in food safety control and drugs.

  11. Antifungal plant defensins: increased insight in their mode of action as a basis for their use to combat fungal infections.

    Science.gov (United States)

    Cools, Tanne L; Struyfs, Caroline; Cammue, Bruno Pa; Thevissen, Karin

    2017-04-01

    Plant defensins are small, cationic peptides with a highly conserved 3D structure. They have been studied extensively in the past decades. Various biological activities have been attributed to plant defensins, such as anti-insect and antimicrobial activities, but they are also known to affect ion channels and display antitumor activity. This review focuses on the structure, biological activity and antifungal mode of action of some well-characterized plant defensins, with particular attention to their fungal membrane target(s), their induced cell death mechanisms as well as their antibiofilm activity. As plant defensins are, in general, not toxic to human cells, show in vivo efficacy and have low frequencies of resistance occurrence, they are of particular interest in the fight against fungal infections.

  12. Unexplored endemic fruit species from Brazil: Antibiofilm properties, insights into mode of action, and systemic toxicity of four Eugenia spp.

    Science.gov (United States)

    Sardi, Janaina de Cássia Orlandi; Freires, Irlan Almeida; Lazarini, Josy Goldoni; Infante, Juliana; de Alencar, Severino Matias; Rosalen, Pedro Luiz

    2017-04-01

    Brazilian endemic fruit species have aroused attention due to their highly valuable, yet unexplored, agro-industrial, food and therapeutic potential. Herein, we describe the antifungal activity of four Eugenia spp. against Candida albicans biofilms, and further demonstrate insights into their potential mode(s) of action and toxicity in vitro and in vivo. Extracts from different parts (seeds, pulps, leaves) of E. leitonii (EL), E. brasiliensis (EB), E. myrcianthes (EM) and E. involucrata (EI) were obtained (S23°23',W45°39') and chemically characterized by GC/MS. The active extracts were tested against C. albicans biofilm viability and architecture, as well as mode of action, and toxicology using RAW 264.7 macrophages and Galleria mellonella larvae. The MIC values ranged from 15.62 to >2000 μg/mL. The most active extracts were EL (seed, 15.62 μg/mL) and EB (leaf and seeds, 31.25 and 15.62 μg/mL, respectively). Treatment with these extracts at 10xMIC reduced biofilm viability by 54-55% (P  0.05) and G. mellonella larvae, with mean in vivo LD 50 of 1500 mg/kg (EL, seeds); 2500 mg/kg (EB, seeds); and 1250 mg/kg (EB, leaf). The phenolic compounds epicatechin and gallic acid were the major constituents in the extracts. Our findings may open avenues for the application of these yet unexplored native fruits in the food and pharmaceutical industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Taxonomic key for the genera of Elmidae (Coleoptera, Byrrhoidea) occurring in Goiás State, Brazil, including new records and distributional notes

    OpenAIRE

    Barbosa, Felipe F.; Fernandes, André S.; Oliveira, Leandro G.

    2013-01-01

    A taxonomic key for the genera of Elmidae (Coleoptera, Byrrhoidea) occurring in Goiás State, Brazil, including new records and distributional notes. Despite their great diversity and high abundance in Neotropical aquatic environments, the fauna of Elmidae remains practically unknown in some areas and even entire biomes in this region. In this work we bring, for the first time, faunistic data for the Elmidae of central Brazil. The aim of this work was to inventory the Elmidae fauna in central,...

  14. A Mini HIP HOP Assay Uncovers a Central Role for Copper and Zinc in the Antifungal Mode of Action of Allicin.

    Science.gov (United States)

    Prescott, Thomas A K; Panaretou, Barry

    2017-05-10

    Garlic contains the organosulfur compound allicin which exhibits potent antifungal activity. Here we demonstrate the use of a highly simplified yeast chemical genetic screen to characterize its mode of action. By screening 24 validated yeast gene deletion "signature" strains for which hypersensitivity is characteristic for common antifungal modes of action, yeast lacking the high affinity Cu 2+ transporter Ctr1 was found to be hypersensitive to allicin. Focusing on transition metal related genes identified two more hypersensitive strains lacking the Cu 2+ and Zn 2+ transcription factors Mac1 and Zap1. Hypersensitivity in these strains was reversed by the addition of Cu 2+ and Zn 2+ ions, respectively. The results suggest the antifungal activity of allicin is mediated through restricted Cu 2+ and Zn 2+ uptake or inhibition of Cu 2+ and Zn 2+ metalloproteins. As certain antimicrobial modes of action are much more common than others, the approach taken here provides a useful way to identify them early on.

  15. An exploratory investigation of various modes of action and potential adverse outcomes of fluoxetine in marine mussels

    International Nuclear Information System (INIS)

    Franzellitti, Silvia; Buratti, Sara; Capolupo, Marco; Du, Bowen; Haddad, Samuel P.; Chambliss, C. Kevin; Brooks, Bryan W.; Fabbri, Elena

    2014-01-01

    Highlights: • Mode of action (MOA) related endpoints and biomarkers of toxicity were assessed in mussels exposed to fluoxetine (FX). • Significant FX bioaccumulation was observed in tissues of mussels exposed to 30 and 300 ng/L FX. • Alterations of cAMP-related cell signaling were observed in exposed mussels as part of the MOA of FX. • FX reduced the health status of mussels inducing lysosomal effects in digestive gland and antioxidant responses in gills. • The importance of considering additional MOAs and adverse outcome pathways for FX impacts on mussels is highlighted. - Abstract: The present study investigated possible adverse outcome pathways (AOPs) of the antidepressant fluoxetine (FX) in the marine mussel Mytilus galloprovincialis. An evaluation of molecular endpoints involved in modes of action (MOAs) of FX and biomarkers for sub-lethal toxicity were explored in mussels after a 7-day administration of nominal FX concentrations encompassing a range of environmentally relevant values (0.03–300 ng/L). FX bioaccumulated in mussel tissues after treatment with 30 and 300 ng/L FX, resulting in bioconcentration factor (BCF) values ranging from 200 to 800, which were higher than expected based solely on hydrophobic partitioning models. Because FX acts as a selective serotonin (5-HT) re-uptake inhibitor increasing serotonergic neurotransmission at mammalian synapses, cell signaling alterations triggered by 5-HT receptor occupations were assessed. cAMP levels and PKA activities were decreased in digestive gland and mantle/gonads of FX-treated mussels, consistent with an increased occupation of 5-HT1 receptors negatively coupled to the cAMP/PKA pathway. mRNA levels of a ABCB gene encoding the P-glycoprotein were also significantly down-regulated. This membrane transporter acts in detoxification towards xenobiotics and in altering pharmacokinetics of antidepressants; moreover, it is under a cAMP/PKA transcriptional regulation in mussels. Potential stress

  16. An exploratory investigation of various modes of action and potential adverse outcomes of fluoxetine in marine mussels

    Energy Technology Data Exchange (ETDEWEB)

    Franzellitti, Silvia, E-mail: silvia.franzellitti@unibo.it [University of Bologna, Interdepartment Centre for Environmental Science Research, via S. Alberto 163, 48123 Ravenna (Italy); University of Bologna, Department of Biological, Geological, and Environmental Sciences, via Selmi 3, 40100 Bologna (Italy); Buratti, Sara; Capolupo, Marco [University of Bologna, Interdepartment Centre for Environmental Science Research, via S. Alberto 163, 48123 Ravenna (Italy); Du, Bowen; Haddad, Samuel P. [Department of Environmental Science, Baylor University, Waco, TX 76798 (United States); Chambliss, C. Kevin [Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798 (United States); Brooks, Bryan W. [Department of Environmental Science, Baylor University, Waco, TX 76798 (United States); Fabbri, Elena [University of Bologna, Interdepartment Centre for Environmental Science Research, via S. Alberto 163, 48123 Ravenna (Italy); University of Bologna, Department of Biological, Geological, and Environmental Sciences, via Selmi 3, 40100 Bologna (Italy)

    2014-06-01

    Highlights: • Mode of action (MOA) related endpoints and biomarkers of toxicity were assessed in mussels exposed to fluoxetine (FX). • Significant FX bioaccumulation was observed in tissues of mussels exposed to 30 and 300 ng/L FX. • Alterations of cAMP-related cell signaling were observed in exposed mussels as part of the MOA of FX. • FX reduced the health status of mussels inducing lysosomal effects in digestive gland and antioxidant responses in gills. • The importance of considering additional MOAs and adverse outcome pathways for FX impacts on mussels is highlighted. - Abstract: The present study investigated possible adverse outcome pathways (AOPs) of the antidepressant fluoxetine (FX) in the marine mussel Mytilus galloprovincialis. An evaluation of molecular endpoints involved in modes of action (MOAs) of FX and biomarkers for sub-lethal toxicity were explored in mussels after a 7-day administration of nominal FX concentrations encompassing a range of environmentally relevant values (0.03–300 ng/L). FX bioaccumulated in mussel tissues after treatment with 30 and 300 ng/L FX, resulting in bioconcentration factor (BCF) values ranging from 200 to 800, which were higher than expected based solely on hydrophobic partitioning models. Because FX acts as a selective serotonin (5-HT) re-uptake inhibitor increasing serotonergic neurotransmission at mammalian synapses, cell signaling alterations triggered by 5-HT receptor occupations were assessed. cAMP levels and PKA activities were decreased in digestive gland and mantle/gonads of FX-treated mussels, consistent with an increased occupation of 5-HT1 receptors negatively coupled to the cAMP/PKA pathway. mRNA levels of a ABCB gene encoding the P-glycoprotein were also significantly down-regulated. This membrane transporter acts in detoxification towards xenobiotics and in altering pharmacokinetics of antidepressants; moreover, it is under a cAMP/PKA transcriptional regulation in mussels. Potential stress

  17. Evaluation of the efficacy and mode of action of biological control for suppression of ganoderma boninense in oil palm

    International Nuclear Information System (INIS)

    Alexander, A.; Abdullah, S.; Rossall, S.; Chong, K.P.

    2017-01-01

    The ability of potential antagonists, a commercial product containing combinations of microorganisms (TR1) to control Ganoderma boninense growth was investigated in this research. TR1 contained multiple strains of Bacillus spp. and Trichoderma spp. The results from field experiments showed that TR1 was all able to reduce the colonization of G. boninense, based on re-isolation of the pathogen onto a selective medium and the reduction of ergosterol content compared to untreated controls. Effectiveness of TR1 was therefore further investigated for mode of action studies. Scanning Electron Microscopy (SEM) observations of Ganoderma mycelium, recovered from bioassay plates on which TR1 had inhibited fungal growth, showed that the mycelium was highly disrupted and lysed after exposure to the treatment. The production of potentially antifungal components produced by TR1 microbes in broth cultures was further investigated using Liquid Chromatography Mass Spectrometry (LCMS). Several antimicrobial compounds, which could inhibit G. boninense were detected, including pyrene-1,6-dione, 12-deoxyaklanonic acid, N-methyl-a-aminoisobutyric acid, 4-O-8',5 - 5'-dehydrotriferulic acid, halstoctacosanolide A, N-acetyl-leu-leu-tyr-amide, 12-oxo-10Z-dodecenoic acid, Gly-Met-OH and lovastatin. These metabolites probably contribute to the antagonistic effect against G. boninense. The use of TR1 could offer an alternative to the use of fungicides and is worthy of further investigation for the control of Ganoderma infection of oil palm. (author)

  18. Cyanobacterial toxins: modes of actions, fate in aquatic and soil ecosystems, phytotoxicity and bioaccumulation in agricultural crops.

    Science.gov (United States)

    Corbel, Sylvain; Mougin, Christian; Bouaïcha, Noureddine

    2014-02-01

    The occurrence of harmful cyanobacterial blooms in surface waters is often accompanied by the production of a variety of cyanotoxins. These toxins are designed to target in humans and animals specific organs on which they act: hepatotoxins (liver), neurotoxins (nervous system), cytotoxic alkaloids, and dermatotoxins (skin), but they often have important side effects too. When introduced into the soil ecosystem by spray irrigation of crops they may affect the same molecular pathways in plants having identical or similar target organs, tissues, cells or biomolecules. There are also several indications that terrestrial plants, including food crop plants, can bioaccumulate cyanotoxins and present, therefore, potential health hazards for human and animals. The number of publications concerned with phytotoxic effects of cyanotoxins on agricultural plants has increased recently. In this review, we first examine different cyanotoxins and their modes of actions in humans and mammals and occurrence of target biomolecules in vegetable organisms. Then we present environmental concentrations of cyanotoxins in freshwaters and their fate in aquatic and soil ecosystems. Finally, we highlight bioaccumulation of cyanotoxins in plants used for feed and food and its consequences on animals and human health. Overall, our review shows that the information on the effects of cyanotoxins on non-target organisms in the terrestrial environment is particularly scarce, and that there are still serious gaps in the knowledge about the fate in the soil ecosystems and phytotoxicity of these toxins. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Mode of Action and Specificity of Bacillus thuringiensis Toxins in the Control of Caterpillars and Stink Bugs in Soybean Culture

    Science.gov (United States)

    Fiuza, Lidia Mariana

    2014-01-01

    The bacterium Bacillus thuringiensis (Bt) produces delta-endotoxins that possess toxic properties and can be used as biopesticides, as well as a source of genes for the construction of transgenic plants resistant to insects. In Brazil, the introduction of Bt soybean with insecticidal properties to the velvetbean caterpillar, the main insect pest of soybean, has been seen a promising tool in the management of these agroecosystems. However, the increase in stink bug populations in this culture, in various regions of the country, which are not susceptible to the existing genetically modified plants, requires application of chemicals that damage the environment. Little is known about the actual toxicity of Bt to Hemiptera, since these insects present sucking mouthparts, which hamper toxicity assays with artificial diets containing toxins of this bacterium. In recent studies of cytotoxicity with the gut of different hemipterans, susceptibility in the mechanism of action of delta-endotoxins has been demonstrated, which can generate promising subsidies for the control of these insect pests in soybean. This paper aims to review the studies related to the selection, application and mode of action of Bt in the biological control of the major pest of soybean, Anticarsia gemmatalis, and an analysis of advances in research on the use of Bt for control hemipterans. PMID:24575310

  20. The Mode of Action of Cyclo(l-Ala-l-Pro) in Inhibiting Aflatoxin Production of Aspergillus flavus.

    Science.gov (United States)

    Iimura, Kurin; Furukawa, Tomohiro; Yamamoto, Toshiyoshi; Negishi, Lumi; Suzuki, Michio; Sakuda, Shohei

    2017-07-12

    Cyclo(l-Ala-l-Pro) inhibits aflatoxin production in aflatoxigenic fungi without affecting fungal growth. The mode of action of cyclo(l-Ala-l-Pro) in inhibiting aflatoxin production of Aspergillus flavus was investigated. A glutathione S -transferase (GST) of the fungus, designated AfGST, was identified as a binding protein of cyclo(l-Ala-l-Pro) in an experiment performed using cyclo(l-Ala-l-Pro)-immobilized Sepharose beads. Cyclo(l-Ala-l-Pro) specifically bound to recombinant AfGST and inhibited its GST activity. Ethacrynic acid, a known GST inhibitor, inhibited the GST activity of recombinant AfGST and aflatoxin production of the fungus. Ethacrynic acid reduced the expression level of AflR, a key regulatory protein for aflatoxin production, similar to cyclo(l-Ala-l-Pro). These results suggest that cyclo(l-Ala-l-Pro) inhibits aflatoxin production by affecting GST function in A. flavus , and that AfGST inhibitors are possible candidates as selective aflatoxin production inhibitors.

  1. Transcriptional profile of diuron-induced toxicity on the urinary bladder of male Wistar rats to inform mode of action.

    Science.gov (United States)

    Ihlaseh, Shadia M; Bailey, Kathryn A; Hester, Susan D; Jones, Carlton; Ren, Hongzu; Cardoso, Ana Paula F; Oliveira, Maria Luiza C S; Wolf, Douglas C; de Camargo, João Lauro V

    2011-08-01

    Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide that induces rat urinary bladder urothelial tumors at high dietary levels (2500 ppm). The specific mode of action and molecular alterations triggered by diuron, however, have not been clarified. The present study evaluated the dose-dependent effects of mucosal alterations and transcriptional changes in the urinary bladder of rats exposed to diuron. Six-week-old male Wistar rats were treated with 0, 60, 125, 1250, and 2500 ppm of diuron in the diet for 20 weeks. Histologic examination showed urothelial hyperplasia present in rats treated with either 1250 or 2500 ppm of diuron but not 60 or 125 ppm. Comprehensive gene expression analyses of urothelial cell RNA were conducted using Affymetrix microarrays. The numbers of differentially expressed transcripts between each treatment group and control increased with diuron dose. Based on similar histology and gene expression responses, the treatment groups were regrouped into a high-dose (1250 and 2500 ppm) and low-dose group (60 and 125 ppm). These data suggest that persistent exposure to high dietary concentrations of diuron induces oxidative stress, increases cellular metabolism, and enhances cell death that is associated with sustained urothelial hyperplasia.

  2. Mode of action and safety of lactosporin, a novel antimicrobial protein produced by Bacillus coagulans ATCC 7050.

    Science.gov (United States)

    Riazi, S; Dover, S E; Chikindas, M L

    2012-09-01

    To determine the mechanism of action of antimicrobial protein, lactosporin, against Gardnerella vaginalis and to evaluate its safety in vitro. Bacillus coagulans ATCC 7050 was grown at 37°C for 18 h. The cell-free supernatant was concentrated 10-fold and screened for antimicrobial activity against indicator strain Micrococcus luteus. The mode of action of lactosporin was determined by measuring the potassium release and monitoring the changes in transmembrane potential (Δψ) and transmembrane pH (ΔpH) of the sensitive cells. Lactosporin caused the efflux of potassium ions from M. luteus cells and dissipation of ΔpH in G. vaginalis, while it had no effect on the Δψ. The safety of lactosporin was evaluated by using EpiVaginal(™) ectocervical (VEC-100) tissue model. Over 80% of the cells in the vaginal tissue remained viable after exposure to lactosporin for 24 h. Lactosporin potentially exerts its antimicrobial activity by selective dissipation of ΔpH and/or by causing leakage of ions from the sensitive cells. Safety studies suggest that lactosporin is a noncytotoxic antimicrobial for vaginal application. This study revealed that lactosporin is an effective and safe antimicrobial preparation with potential application for the control of bacterial vaginosis. No claim to US Government works Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  3. Biological approaches to characterize the mode of action of two 5-nitroindazolinone prototypes on Trypanosoma cruzi bloodstream trypomastigotes.

    Science.gov (United States)

    Fonseca-Berzal, Cristina; DA Silva, Cristiane França; Menna-Barreto, Rubem F S; Batista, Marcos Meuser; Escario, José A; Arán, Vicente J; Gómez-Barrio, Alicia; Soeiro, Maria DE Nazaré C

    2016-09-01

    The phenotypic activity of two 5-nitroindazolinones, i.e. 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives, previously proposed as anti-Trypanosoma cruzi prototypes, was presently assayed on bloodstream trypomastigotes (BT) of the moderately drug-resistant Y strain. Further exploration of putative targets and cellular mechanisms involved in their activity was also carried out. Therefore, transmission electron microscopy, high-resolution respirometry and flow cytometry procedures were performed on BT treated for up to 24 h with the respective EC50 value of each derivative. Results demonstrated that although 22 and 24 were not as active as benznidazole in this in vitro assay on BT, both compounds triggered important damages in T. cruzi that lead to the parasite death. Ultrastructural alterations included shedding events, detachment of plasma membrane and nuclear envelope, loss of mitochondrial integrity, besides the occurrence of a large number of intracellular vesicles and profiles of endoplasmic reticulum surrounding cytoplasmic organelles such as mitochondrion. Moreover, both derivatives affected mitochondrion leading to this organelle dysfunction, as reflected by the inhibition in oxygen consumption and the loss of mitochondrial membrane potential. Altogether, the findings exposed in the present study propose autophagic processes and mitochondrial machinery as part of the mode of action of both 5-nitroindazolinones 22 and 24 on T. cruzi trypomastigotes.

  4. Graphene-Borate as an Efficient Fire Retardant for Cellulosic Materials with Multiple and Synergetic Modes of Action.

    Science.gov (United States)

    Nine, Md J; Tran, Diana N H; Tung, Tran Thanh; Kabiri, Shervin; Losic, Dusan

    2017-03-22

    To address high fire risks of flamable cellulosic materials, that can trigger easy combustion, flame propagation, and release of toxic gases, we report a new fire-retardant approach using synergetic actions combining unique properties of reduced graphene oxide (rGO) and hydrated-sodium metaborates (SMB). The single-step treatment of cellulosic materials by a composite suspension of rGO/SMB was developed to create a barrier layer on sawdust surface providing highly effective fire retardant protection with multiple modes of action. These performances are designed considering synergy between properties of hydrated-SMB crystals working as chemical heat-sink to slow down the thermal degradation of the cellulosic particles and gas impermeable rGO layers that prevents access of oxygen and the release of toxic volatiles. The rGO outer layer also creates a thermal and physical barrier by donating carbon between the flame and unburnt wood particles. The fire-retardant performance of developed graphene-borate composite and mechanism of fire protection are demonstrated by testing of different forms of cellulosic materials such as pine sawdust, particle-board, and fiber-based structures. Results revealed their outstanding self-extinguishing behavior with significant resistance to release of toxic and flammable volatiles suggesting rGO/SMB to be suitable alternative to the conventional toxic halogenated flame-retardant materials.

  5. Meleagrin, a new FabI inhibitor from Penicillium chryosogenum with at least one additional mode of action.

    Directory of Open Access Journals (Sweden)

    Chang Ji Zheng

    Full Text Available Bacterial enoyl-acyl carrier protein reductase (FabI is a promising novel antibacterial target. We isolated a new class of FabI inhibitor from Penicillium chrysogenum, which produces various antibiotics, the mechanisms of some of them are unknown. The isolated FabI inhibitor was determined to be meleagrin by mass spectroscopy and nuclear magnetic resonance spectral analyses, and its more active and inactive derivatives were chemically prepared. Consistent with their selective inhibition of Staphylococcus aureus FabI, meleagrin and its more active derivatives directly bound to S. aureus FabI in a fluorescence quenching assay, inhibited intracellular fatty acid biosynthesis and growth of S. aureus, and increased the minimum inhibitory concentration for fabI-overexpressing S. aureus. The compounds that were not effective against the FabK isoform, however, inhibited the growth of Streptococcus pneumoniae that contained only the FabK isoform. Additionally no resistant mutant to the compounds was obtained. Importantly, fabK-overexpressing Escherichia coli was not resistant to these compounds, but was resistant to triclosan. These results demonstrate that the compounds inhibited another target in addition to FabI. Thus, meleagrin is a new class of FabI inhibitor with at least one additional mode of action that could have potential for treating multidrug-resistant bacteria.

  6. Efficacy of Combined Formulations of Fungicides with Different Modes of Action in Controlling Botrytis Gray Mold Disease in Chickpea

    Directory of Open Access Journals (Sweden)

    M. H. Rashid

    2014-01-01

    Full Text Available Botrytis gray mold (BGM caused by Botrytis cinerea Pers. Ex. Fr. is an extremely devastating disease of chickpea (Cicer arietinum L. and has a regional as well as an international perspective. Unfortunately, nonchemical methods for its control are weak and ineffective. In order to identify an effective control measure, six fungicides with different modes of action were evaluated on a BGM susceptible chickpea variety BARIchhola-1 at a high BGM incidence location (Madaripur in Bangladesh for three years (2008, 2009, and 2010. Among the six fungicides tested, one was protectant [Vondozeb 42SC, a.i. mancozeb (0.2%], two systemic [Bavistin 50 WP, a.i. carbendazim (0.2%, and Protaf 250EC, propiconazole (0.05%], and three combination formulations [Acrobat MZ690, dimethomorph 9% + mancozeb 60%, (0.2%; Secure 600 WG, phenomadone + mancozeb (0.2%; and Companion, mancozeb 63% + carbendazim 12% (0.2%]. The results showed superiority of combination formulations involving both protectant and systemic fungicides over the sole application of either fungicide separately. Among the combination fungicides, Companion was most effective, resulting in the lowest disease severity (3.33 score on 1–9 scale and the highest increase (38% of grain yield in chickpea. Therefore, this product could be preferred over the sole application of either solo protectant or systemic fungicides to reduce yield losses and avoid fungicide resistance.

  7. Efficacy of combined formulations of fungicides with different modes of action in controlling botrytis gray mold disease in chickpea.

    Science.gov (United States)

    Rashid, M H; Hossain, M Ashraf; Kashem, M A; Kumar, Shiv; Rafii, M Y; Latif, M A

    2014-01-01

    Botrytis gray mold (BGM) caused by Botrytis cinerea Pers. Ex. Fr. is an extremely devastating disease of chickpea (Cicer arietinum L.) and has a regional as well as an international perspective. Unfortunately, nonchemical methods for its control are weak and ineffective. In order to identify an effective control measure, six fungicides with different modes of action were evaluated on a BGM susceptible chickpea variety BARIchhola-1 at a high BGM incidence location (Madaripur) in Bangladesh for three years (2008, 2009, and 2010). Among the six fungicides tested, one was protectant [Vondozeb 42SC, a.i. mancozeb (0.2%)], two systemic [Bavistin 50 WP, a.i. carbendazim (0.2%), and Protaf 250EC, propiconazole (0.05%)], and three combination formulations [Acrobat MZ690, dimethomorph 9% + mancozeb 60%, (0.2%); Secure 600 WG, phenomadone + mancozeb (0.2%); and Companion, mancozeb 63% + carbendazim 12% (0.2%)]. The results showed superiority of combination formulations involving both protectant and systemic fungicides over the sole application of either fungicide separately. Among the combination fungicides, Companion was most effective, resulting in the lowest disease severity (3.33 score on 1-9 scale) and the highest increase (38%) of grain yield in chickpea. Therefore, this product could be preferred over the sole application of either solo protectant or systemic fungicides to reduce yield losses and avoid fungicide resistance.

  8. Combining QSAR Modeling and Text-Mining Techniques to Link Chemical Structures and Carcinogenic Modes of Action.

    Science.gov (United States)

    Papamokos, George; Silins, Ilona

    2016-01-01

    There is an increasing need for new reliable non-animal based methods to predict and test toxicity of chemicals. Quantitative structure-activity relationship (QSAR), a computer-based method linking chemical structures with biological activities, is used in predictive toxicology. In this study, we tested the approach to combine QSAR data with literature profiles of carcinogenic modes of action automatically generated by a text-mining tool. The aim was to generate data patterns to identify associations between chemical structures and biological mechanisms related to carcinogenesis. Using these two methods, individually and combined, we evaluated 96 rat carcinogens of the hematopoietic system, liver, lung, and skin. We found that skin and lung rat carcinogens were mainly mutagenic, while the group of carcinogens affecting the hematopoietic system and the liver also included a large proportion of non-mutagens. The automatic literature analysis showed that mutagenicity was a frequently reported endpoint in the literature of these carcinogens, however, less common endpoints such as immunosuppression and hormonal receptor-mediated effects were also found in connection with some of the carcinogens, results of potential importance for certain target organs. The combined approach, using QSAR and text-mining techniques, could be useful for identifying more detailed information on biological mechanisms and the relation with chemical structures. The method can be particularly useful in increasing the understanding of structure and activity relationships for non-mutagens.

  9. Mode of action of cupping--local metabolism and pain thresholds in neck pain patients and healthy subjects.

    Science.gov (United States)

    Emerich, M; Braeunig, M; Clement, H W; Lüdtke, R; Huber, R

    2014-02-01

    Cupping worldwide has been part of traditional medicine systems and is in the western world used as CAM therapy mainly for treating pain syndromes. The mode of action is up to now unclear. In order to investigate its mechanism we measured in parallel metabolic changes in the tissue under the cupping glass and pressure pain thresholds. In 12 volunteers (6 healthy subjects and 6 patients with chronic neck pain) a microdialysis system was implanted subcutaneously on both sides (left and right) above the trapezius muscle. After baseline measures cupping was performed at one randomly selected side (left or right), the other side served as control. Every 20 min during baseline measures and for 280 min after cupping, microdialysis probes for detection of lactate, pyruvate, glucose and glycerin were taken. In addition, pain thresholds were measured before and after cupping with algometry. Cupping resulted in a strong increase of lactate (beginning 160 min after cupping until the end of the measurements) and the lactate/pyruvate ratio, indicating an anaerobe metabolism in the surrounding tissue. Baseline pain thresholds were non-significantly lower in neck pain patients compared to healthy controls and slightly increased immediately after cupping (ppain patients). After 280 min no more significant changes of pain thresholds were detected. Cupping induces >280 min lasting anaerobe metabolism in the subcutaneous tissue and increases immediate pressure pain thresholds in some areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Use of Electroencephalography (EEG) to Assess CNS Changes Produced by Pesticides with different Modes of Action: Effects of Permethrin, Deltamethrin, Fipronil, Imidacloprid, Carbaryl, and Triadimefon

    Science.gov (United States)

    The electroencephalogram (EEG) is an apical measure, capable of detecting changes in brain neuronal activity produced by internal or external stimuli. We assessed whether pesticides with different modes of action produced different changes in the EEG of adult male Long-Evans rats...

  11. Meta-Analysis of Fish Early Life Stage Tests - Association of Toxic Ratios and Acute-To-Chronic Ratios with Modes of Action

    DEFF Research Database (Denmark)

    Scholz, Stefan; Schreiber, Rene; Armitage, James

    2018-01-01

    Fish early life stage (FELS) tests (OECD test guideline 210) are widely conducted to estimate chronic fish toxicity. In these tests, fish are exposed from the embryonic to the juvenile life stage. In order to analyse whether certain modes of action are related to high toxic ratios (TR, i.e., rati...

  12. Developmental Triclosan Exposure Decreases Maternal,Fetal, and Early Neonatal Thyroxine: Dynamic and Kinetic Data Support for a Mode-of-Action

    Science.gov (United States)

    This work tests the mode-of-action (MOA) hypothesis that perinatal triclosan (TCS) exposure decreases circulating thyroxine (T4) concentrations via activation of pregnane X and/or constitutive androstane receptors (PXR, CAR), resulting in up-regulation of hepatic catabolism and e...

  13. Meta-Analysis of Fish Early Life Stage Tests - Association of Toxic Ratios and Acute-To-Chronic Ratios with Modes of Action

    DEFF Research Database (Denmark)

    Scholz, Stefan; Schreiber, Rene; Armitage, James

    2018-01-01

    Fish early life stage (FELS) tests (OECD test guideline 210) are widely conducted to estimate chronic fish toxicity. In these tests, fish are exposed from the embryonic to the juvenile life stage. In order to analyse whether certain modes of action are related to high toxic ratios (TR, i.e., ratios...

  14. The Mode of Action of Isocyanide in Three Aquatic Organisms, Balanus amphitrite, Bugula neritina and Danio rerio

    KAUST Repository

    Zhang, Yi-Fan

    2012-09-18

    Isocyanide is a potential antifouling compound in marine environments. In this study, we investigated its mode of action in three aquatic organisms. Two of them, the bryozoan Bugula neritina and the barnacle Balanus amphitrite, are major marine fouling invertebrates, and the other organism is the non-target species zebrafish Danio rerio. In the swimming larvae of B. neritina, isocyanide did not affect the total attachment rate (≤50 µg ml^(−1)), but it did change the attachment site by increasing the percentage of attachment on the bottom of the container rather than on the wall or air-water inter-surface. Isocyanide binds several proteins in B. neritina as identified via SDS-PAGE-LC-MS/MS: 1) a 30 kD protein band containing two proteins similar to voltage dependent anion channels (VDAC), which control the direct coupling of the mitochondrial matrix to the energy maintenance of the cytosol and the release of apoptogenic factors from mitochondria of mammalian cells; and 2) an unknown 39 kD protein. In B. amphitrite cyprids, the isocyanide binding protein were 1) a protein similar to NADH-ubiquinone oxidoreductase, which is the “entry enzyme” of oxidative phosphorylation in mitochondria; and 2) cytochrome P450. In Danio rerio embryos, isocyanide caused “wavy” notochords, hydrocephalus, pericardial edema, poor blood circulation, and defects in pigmentation and hematopoiesis, which phenocopied copper deficiency. This is the first report on isocyanide binding proteins in fouling organisms, as well as the first description of its phenotype and potential toxicology in zebrafish.

  15. Antifungal activity, mode of action and anti-biofilm effects of Laurus nobilis Linnaeus essential oil against Candida spp.

    Science.gov (United States)

    Peixoto, Larissa Rangel; Rosalen, Pedro Luiz; Ferreira, Gabriela Lacet Silva; Freires, Irlan Almeida; de Carvalho, Fabíola Galbiatti; Castellano, Lúcio Roberto; de Castro, Ricardo Dias

    2017-01-01

    The present study demonstrated the antifungal potential of the chemically characterized essential oil (EO) of Laurus nobilis L. (bay laurel) against Candida spp. biofilm adhesion and formation, and further established its mode of action on C. albicans. L. nobilis EO was obtained and tested for its minimum inhibitory and fungicidal concentrations (MIC/MFC) against Candida spp., as well as for interaction with cell wall biosynthesis and membrane ionic permeability. Then we evaluated its effects on the adhesion, formation, and reduction of 48hC. albicans biofilms. The EO phytochemical profile was determined by gas chromatography coupled to mass spectrometry (GC/MS). The MIC and MFC values of the EO ranged from (250 to 500) μg/mL. The MIC values increased in the presence of sorbitol (osmotic protector) and ergosterol, which indicates that the EO may affect cell wall biosynthesis and membrane ionic permeability, respectively. At 2 MIC the EO disrupted initial adhesion of C. albicans biofilms (p0.05). When applied for 1min, every 8h, for 24h and 48h, the EO reduced the amount of C. albicans mature biofilm with no difference in relation to nystatin (p>0.05). The phytochemical analysis identified isoeugenol as the major compound (53.49%) in the sample. L. nobilis EO has antifungal activity probably due to monoterpenes and sesquiterpenes in its composition. This EO may affect cell wall biosynthesis and membrane permeability, and showed deleterious effects against C. albicans biofilms. Copyright © 2016. Published by Elsevier Ltd.

  16. Cytotoxicity and regenerative proliferation as the mode of action for diuron-induced urothelial carcinogenesis in the rat.

    Science.gov (United States)

    da Rocha, Mitscheli S; Nascimento, Merielen G; Cardoso, Ana Paula F; de Lima, Patrícia L A; Zelandi, Edneia A; de Camargo, João Lauro V; de Oliveira, Maria Luiza C S

    2010-01-01

    Diuron, a substituted urea herbicide, is carcinogenic to the urinary bladder of rats at high dietary levels. Its proposed carcinogenic mode of action (MOA) includes urothelial cytotoxicity and necrosis followed by regenerative cell proliferation and sustained urothelial hyperplasia. Cytotoxicity could be induced either by urinary solids or by chemical toxicity by diuron and/or metabolites excreted in the urine. Diuron was not genotoxic in a previous single-cell gel (comet) assay, but possible cross-linking activity remained to be evaluated. The present study explored the MOA of diuron and the effect of urinary acidification on the development of urothelial lesions. Male Wistar rats were fed diuron (2500 ppm, about 130 mg/kg of body weight) either with or without NH(4)Cl 10,000 ppm to acidify the urine. Reversibility of urothelial changes was also examined. The animals were euthanized after 15, 25, or 30 weeks. Diuron-fed rats had urinary amorphous precipitate and magnesium ammonium phosphate crystals similar to control animals. Groups treated with diuron + NH(4)Cl showed decreased urinary pH and reduced amounts of urinary crystals and precipitate. Urothelial necrosis and simple hyperplasia were observed by light microscopy and scanning electron microscopy both in diuron- and in diuron + NH(4)Cl-treated groups. Cytotoxicity and proliferative changes were mostly reversible. A modified comet assay developed in vitro with Chinese hamster ovary cells showed that diuron did not induce DNA cross-links. These data suggest that cytotoxicity with consequent regenerative cell proliferation is the predominant MOA for diuron rat urothelial carcinogenesis, the cytotoxicity being chemically induced and not due to urinary solids.

  17. Toward Understanding the Cold, Hot, and Neutral Nature of Chinese Medicines Using in Silico Mode-of-Action Analysis.

    Science.gov (United States)

    Fu, Xianjun; Mervin, Lewis H; Li, Xuebo; Yu, Huayun; Li, Jiaoyang; Mohamad Zobir, Siti Zuraidah; Zoufir, Azedine; Zhou, Yang; Song, Yongmei; Wang, Zhenguo; Bender, Andreas

    2017-03-27

    One important, however, poorly understood, concept of Traditional Chinese Medicine (TCM) is that of hot, cold, and neutral nature of its bioactive principles. To advance the field, in this study, we analyzed compound-nature pairs from TCM on a large scale (>23 000 structures) via chemical space visualizations to understand its physicochemical domain and in silico target prediction to understand differences related to their modes-of-action (MoA) against proteins. We found that overall TCM natures spread into different subclusters with specific molecular patterns, as opposed to forming coherent global groups. Compounds associated with cold nature had a lower clogP and contain more aliphatic rings than the other groups and were found to control detoxification, heat-clearing, heart development processes, and have sedative function, associated with "Mental and behavioural disorders" diseases. While compounds associated with hot nature were on average of lower molecular weight, have more aromatic ring systems than other groups, frequently seemed to control body temperature, have cardio-protection function, improve fertility and sexual function, and represent excitatory or activating effects, associated with "endocrine, nutritional and metabolic diseases" and "diseases of the circulatory system". Compounds associated with neutral nature had a higher polar surface area and contain more cyclohexene moieties than other groups and seem to be related to memory function, suggesting that their nature may be a useful guide for their utility in neural degenerative diseases. We were hence able to elucidate the difference between different nature classes in TCM on the molecular level, and on a large data set, for the first time, thereby helping a better understanding of TCM nature theory and bridging the gap between traditional medicine and our current understanding of the human body.

  18. Assessment of possible carcinogenicity of oxyfluorfen to humans using mode of action analysis of rodent liver effects.

    Science.gov (United States)

    Stagg, Nicola J; LeBaron, Matthew J; Eisenbrandt, David L; Gollapudi, B Bhaskar; Klaunig, James E

    2012-08-01

    Oxyfluorfen is a herbicide that is not genotoxic and produces liver toxicity in rodents, following repeated administration at high dose levels. Lifetime rodent feeding studies reported in 1977 with low-purity oxyfluorfen (85%) showed no increase in any tumor type in rats (800 ppm, high dose) and only a marginally increased incidence of hepatocellular tumors in male CD-1 mice at the highest dose (200 ppm). To evaluate the potential carcinogenicity of the currently registered oxyfluorfen (> 98% purity), we conducted a series of short-term liver mode of action (MOA) toxicology studies in male CD-1 mice administered dietary doses of 0, 40, 200, 800, and 1600 ppm for durations of 3, 7, 10, or 28 days. MOA endpoints examined included liver weight, histopathology, cell proliferation, nuclear receptor-mediated gene expression, and other peroxisome proliferator-specific endpoints and their reversibility. Minimal liver effects were observed in mice administered doses at or below 200 ppm for up to 28 days. Increased liver weight, single-cell necrosis, cell proliferation, and peroxisomal acyl-CoA oxidase (ACO) were observed at 800 ppm after 28 days, but there was no increase in peroxisomes. Expression of Cyp2b10 and Cyp4a10 transcripts, markers of constitutive androstane receptor and peroxisome proliferator activated receptor α nuclear receptor activation, respectively, were increased at 800 and 1600 ppm after 3 or 10 days. Collectively, these data along with the negative genotoxicity demonstrate that oxyfluorfen (> 98% purity) has the potential to induce mouse liver tumors through a nongenotoxic, mitogenic MOA with a clear threshold and is not predicted to be carcinogenic in humans at relevant exposure levels.

  19. The mode of action of isocyanide in three aquatic organisms, Balanus amphitrite, Bugula neritina and Danio rerio.

    Directory of Open Access Journals (Sweden)

    Yi-Fan Zhang

    Full Text Available Isocyanide is a potential antifouling compound in marine environments. In this study, we investigated its mode of action in three aquatic organisms. Two of them, the bryozoan Bugula neritina and the barnacle Balanus amphitrite, are major marine fouling invertebrates, and the other organism is the non-target species zebrafish Danio rerio. In the swimming larvae of B. neritina, isocyanide did not affect the total attachment rate (≤50 µg ml(-1, but it did change the attachment site by increasing the percentage of attachment on the bottom of the container rather than on the wall or air-water inter-surface. Isocyanide binds several proteins in B. neritina as identified via SDS-PAGE-LC-MS/MS: 1 a 30 kD protein band containing two proteins similar to voltage dependent anion channels (VDAC, which control the direct coupling of the mitochondrial matrix to the energy maintenance of the cytosol and the release of apoptogenic factors from mitochondria of mammalian cells; and 2 an unknown 39 kD protein. In B. amphitrite cyprids, the isocyanide binding protein were 1 a protein similar to NADH-ubiquinone oxidoreductase, which is the "entry enzyme" of oxidative phosphorylation in mitochondria; and 2 cytochrome P450. In Danio rerio embryos, isocyanide caused "wavy" notochords, hydrocephalus, pericardial edema, poor blood circulation, and defects in pigmentation and hematopoiesis, which phenocopied copper deficiency. This is the first report on isocyanide binding proteins in fouling organisms, as well as the first description of its phenotype and potential toxicology in zebrafish.

  20. Role of iodine in diiodomethyl-p-tolylsulfone induced reproductive toxicity in rats: proposed mode of action.

    Science.gov (United States)

    Saghir, Shakil A; Yano, Barry L; Zablotny, Carol L; Carney, Edward W

    2012-04-01

    The biocide diiodomethyl-p-tolylsulfone (DIMPTS) caused dystocia, decreased neonatal survival and hypothyroidism in rat reproduction studies resembling the effects caused by iodine. One molecule of DIMPTS contains two iodine moieties that are hydrolyzed upon ingestion and systemically absorbed, suggesting iodine toxicity as a probable mode of action for the effects observed in rats. This study compared the effects induced by DIMPTS and an equimolar concentration of its de-iodinated analogue, methyl-p-tolylsulfone (MPTS). Groups of 20 female Sprague Dawley rats were fed diets supplying 80 mg DIMPTS/kg/day, 32 mg MPTS/kg/day or control feed from prior to breeding through lactation and gonadal function, mating performance, conception, gestation, parturition, lactation, survival, growth and development of pups evaluated through postnatal day 7. Serum thyroid hormones and iodine levels in milk and sera were also determined. Females given DIMPTS had increased incidence of vulvar discharge and dystocia, decreased litter size, decreased body weights and feed consumption, increased thyroid weights, thyroid follicular cell hypertrophy with decreased colloid, decreased triidothyronine, and increased thyroid stimulating hormone levels. DIMPTS pups had decreased neonatal survival and body weights. These effects were associated with elevated levels of iodine in milk and sera. In contrast, MPTS did not produce similar effects in adult females or their offspring. These data support the hypothesis that the dystocia, altered neonatal survival and hypothyroidism following repeated dietary administration of DIMPTS were due to excessive iodine released from DIMPTS during absorption and metabolism. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Synergistic activity of luteolin and amoxicillin combination against amoxicillin-resistant Escherichia coli and mode of action.

    Science.gov (United States)

    Eumkeb, G; Siriwong, S; Thumanu, K

    2012-12-05

    The purpose of this research was to investigate whether luteolin has antibacterial and synergistic activity against amoxicillin-resistant Escherichia coli (AREC) when use singly and in combination with amoxicillin. The primarily mode of action is also investigated. The susceptibility assay (minimum inhibitory concentration and checkerboard determination) was carried out by the broth macrodilution method's in Müeller-Hinton medium. MIC and checkerboard determination were carried out after 20 h of incubation at 35°C by observing turbidity. The MICs of amoxicillin and luteolin against all AREC strains were >1000 and ≥ 200 μg/ml respectively. Synergistic activity were observed on amoxicillin plus luteolin against these strains. Viable count of this combination showed synergistic effect by reducing AREC cell numbers. The results indicated that this combination altered both outer and inner membrane permeabilisation. Enzyme assay showed that luteolin had an inhibitory activity against penicillinase. Fourier Transform-Infrared (FT-IR) spectroscopy exhibited that luteolin alone and when combined with amoxicillin caused increase in fatty acid and nucleic acid, but decrease in amide I of proteins in bacterial envelops compared with control. These results indicated that luteolin has the potential to reverse bacterial resistance to amoxicillin in AREC and may operate via three mechanisms: inhibition of proteins and peptidoglycan synthesis, inhibition of the activity of certain extended-spectrum β-lactamases and alteration of outer and inner membrane permeability. These findings offer the potential to develop a new generation of phytopharmaceuticals to treat AREC. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Cardiac disorders and mode of action of the Egyptian scorpion venom Androctonus bicolor on isolated toad’s heart

    Directory of Open Access Journals (Sweden)

    Mohamed A. Abdel-Rahman

    2015-10-01

    Full Text Available Scorpion venom is a complex mixture of components with various pharmacological and toxicological effects. It is characterized by the presence of a large number of toxins that specifically interact with ion channels of excitable cells. The Egyptian scorpion Androctonus bicolor belongs to the family of Buthidae and until now no information is available about the effect of its venom on cardiac muscles. Using an in vitro approach, cardiotoxicity and mode of action of A. bicolor venom on isolated toad’s heart were investigated. Direct application of scorpion venom (0.5 μg/ml into isolated toad’s heart induced a remarkable bradycardia concomitant with a protraction in the conduction time (P–R interval. In the meantime, a significant increase in the R-wave amplitude (ventricular contraction was noticed after 5 min of venom perfusion. Various cases of cardiac disorders were recorded such as sinus arrhythmias, ectopic beats and different degrees of heart block. Through using different autonomic and ion channel blockers, the possible mechanism of action of A. bicolor venom on isolated toad’s heart was revealed. The application of both atropine (4 μg/ml and verapamil (5 μg/ml could not alleviate the pronounced negative chronotropic and positive inotropic effects. Meanwhile, a significant decrease in the R-wave amplitude was observed after propranolol (5 μg/ml application. In conclusion, our findings indicate that the venom of A. bicolor directly influenced the cardiac electrical activity of toads through β-adrenergic receptors. The direct effect of this venom on cardiac tissues may significantly contribute in the development of several cardiotoxic effects following scorpion sting.

  3. Coexpression of nuclear receptors and histone methylation modifying genes in the testis: implications for endocrine disruptor modes of action.

    Directory of Open Access Journals (Sweden)

    Alison M Anderson

    Full Text Available BACKGROUND: Endocrine disruptor chemicals elicit adverse health effects by perturbing nuclear receptor signalling systems. It has been speculated that these compounds may also perturb epigenetic mechanisms and thus contribute to the early origin of adult onset disease. We hypothesised that histone methylation may be a component of the epigenome that is susceptible to perturbation. We used coexpression analysis of publicly available data to investigate the combinatorial actions of nuclear receptors and genes involved in histone methylation in normal testis and when faced with endocrine disruptor compounds. METHODOLOGY/PRINCIPAL FINDINGS: The expression patterns of a set of genes were profiled across testis tissue in human, rat and mouse, plus control and exposed samples from four toxicity experiments in the rat. Our results indicate that histone methylation events are a more general component of nuclear receptor mediated transcriptional regulation in the testis than previously appreciated. Coexpression patterns support the role of a gatekeeper mechanism involving the histone methylation modifiers Kdm1, Prdm2, and Ehmt1 and indicate that this mechanism is a common determinant of transcriptional integrity for genes critical to diverse physiological endpoints relevant to endocrine disruption. Coexpression patterns following exposure to vinclozolin and dibutyl phthalate suggest that coactivity of the demethylase Kdm1 in particular warrants further investigation in relation to endocrine disruptor mode of action. CONCLUSIONS/SIGNIFICANCE: This study provides proof of concept that a bioinformatics approach that profiles genes related to a specific hypothesis across multiple biological settings can provide powerful insight into coregulatory activity that would be difficult to discern at an individual experiment level or by traditional differential expression analysis methods.

  4. Anticancer drug mithramycin interacts with core histones: An additional mode of action of the DNA groove binder

    Directory of Open Access Journals (Sweden)

    Amrita Banerjee

    2014-01-01

    Full Text Available Mithramycin (MTR is a clinically approved DNA-binding antitumor antibiotic currently in Phase 2 clinical trials at National Institutes of Health for treatment of osteosarcoma. In view of the resurgence in the studies of this generic antibiotic as a human medicine, we have examined the binding properties of MTR with the integral component of chromatin – histone proteins – as a part of our broad objective to classify DNA-binding molecules in terms of their ability to bind chromosomal DNA alone (single binding mode or both histones and chromosomal DNA (dual binding mode. The present report shows that besides DNA, MTR also binds to core histones present in chromatin and thus possesses the property of dual binding in the chromatin context. In contrast to the MTR–DNA interaction, association of MTR with histones does not require obligatory presence of bivalent metal ion like Mg2+. As a consequence of its ability to interact with core histones, MTR inhibits histone H3 acetylation at lysine 18, an important signature of active chromatin, in vitro and ex vivo. Reanalysis of microarray data of Ewing sarcoma cell lines shows that upon MTR treatment there is a significant down regulation of genes, possibly implicating a repression of H3K18Ac-enriched genes apart from DNA-binding transcription factors. Association of MTR with core histones and its ability to alter post-translational modification of histone H3 clearly indicates an additional mode of action of this anticancer drug that could be implicated in novel therapeutic strategies.

  5. QSAR analysis and specific endpoints for classifying the physiological modes of action of biocides in synchronous green algae.

    Science.gov (United States)

    Neuwoehner, Judith; Junghans, Marion; Koller, Mirjam; Escher, Beate I

    2008-10-20

    We propose the use of additional physiological endpoints in the 24h growth inhibition test with synchronous cultures of Scenedesmus vacuolatus for the classification of physiological modes of toxic action of chemicals in green algae. The classification scheme is illustrated on the example of one baseline toxicant (3-nitroaniline) and five biocides (irgarol, diuron, Sea-Nine, tributyltin (TBT) and norflurazon). The well-established endpoint of inhibition of reproduction is used for an analysis of the degree of specificity of toxicity by comparing the experimental data with predictions from a quantitative structure-activity relationship (QSAR) for baseline toxicity (narcosis). For those compounds with a toxic ratio greater than 10, i.e. a 10 times higher effect in reproduction than predicted by baseline toxicity, additionally the physiological endpoints inhibition of photosynthesis, cell division and cell volume growth were experimentally assessed. Depending on the relative sensitivity of the different endpoints the chemicals were classified into five different classes of modes of toxic action using a flow chart that was developed in the present study. The advantage of the novel classification scheme is the simplicity of the experimental approach. For the determination of the inhibition of reproduction, the cell size and numbers are quantified with a particle analyzer. This information can be used to derive also the physiological endpoints of cell volume growth and inhibition of cell division. The only additional measurement is the inhibition of the photosynthesis efficiency, which can be easily performed using the non-invasive saturation pulse method and pulse-modulated chlorophyll fluorometry with the Tox-Y-PAM instrument. This mechanistic approach offers a great future potential in ecotoxicology for the physiological mode of action classification of chemicals in algae, which should be a crucial step considered in the risk assessment of chemicals.

  6. Differential Gel Electrophoresis (DIGE Evaluation of Naphthoimidazoles Mode of Action: A Study in Trypanosoma cruzi Bloodstream Trypomastigotes.

    Directory of Open Access Journals (Sweden)

    Giselle Villa Flor Brunoro

    2016-08-01

    Full Text Available The obligate intracellular protozoan Trypanosoma cruzi is the causative agent of Chagas disease, a neglected illness affecting millions of people in Latin America that recently entered non-endemic countries through immigration, as a consequence of globalization. The chemotherapy for this disease is based mainly on benznidazole and nifurtimox, which are very efficient nitroderivatives against the acute stage but present limited efficacy during the chronic phase. Our group has been studying the trypanocidal effects of naturally occurring quinones and their derivatives, and naphthoimidazoles derived from β-lapachone N1, N2 and N3 were the most active. To assess the molecular mechanisms of action of these compounds, we applied proteomic techniques to analyze treated bloodstream trypomastigotes, which are the clinically relevant stage of the parasite.The approach consisted of quantification by 2D-DIGE followed by MALDI-TOF/TOF protein identification. A total of 61 differentially abundant protein spots were detected when comparing the control with each N1, N2 or N3 treatment, for 34 identified spots. Among the differentially abundant proteins were activated protein kinase C receptor, tubulin isoforms, asparagine synthetase, arginine kinase, elongation factor 2, enolase, guanine deaminase, heat shock proteins, hypothetical proteins, paraflagellar rod components, RAB GDP dissociation inhibitor, succinyl-CoA ligase, ATP synthase subunit B and methionine sulfoxide reductase.Our results point to different modes of action for N1, N2 and N3, which indicate a great variety of metabolic pathways involved and allow for novel perspectives on the development of trypanocidal agents.

  7. Mechanistic insights into mode of action of potent natural antagonists of BACE-1 for checking Alzheimer’s plaque pathology

    Energy Technology Data Exchange (ETDEWEB)

    Dhanjal, Jaspreet Kaur [School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067 (India); Goyal, Sukriti [Apaji Institute of Mathematics and Applied Computer Technology, Banasthali University, Tonk 304022, Rajasthan (India); Sharma, Sudhanshu [Department of Biotechnology, Delhi Technological University, New Delhi 110042 (India); Hamid, Rabia [Department of Biochemistry, University of Kashmir, Srinagar 190006 (India); Grover, Abhinav, E-mail: abhinavgr@gmail.com [School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067 (India)

    2014-01-17

    Highlights: •Accumulation of Aβ plaques is one of the major pathology associated with Alzheimer’s disease. •Inhibition of β-Secretase or BACE-1 offers a viable prospect to check the growth of these plaques. •A large virtual dataset of natural compounds was screened against BACE-1. •Top two hits were analyzed for thermodynamic and structural stability using MD simulations. •Their detailed binding mode of actions were elucidated. -- Abstract: Alzheimer’s is a neurodegenerative disorder resulting in memory loss and decline in cognitive abilities. Accumulation of extracellular beta amyloidal plaques is one of the major pathology associated with this disease. β-Secretase or BACE-1 performs the initial and rate limiting step of amyloidic pathway in which 37–43 amino acid long peptides are generated which aggregate to form plaques. Inhibition of this enzyme offers a viable prospect to check the growth of these plaques. Numerous efforts have been made in recent years for the generation of BACE-1 inhibitors but many of them failed during the preclinical or clinical trials due to drug related or drug induced toxicity. In the present work, we have used computational methods to screen a large dataset of natural compounds to search for small molecules having BACE-1 inhibitory activity with low toxicity to normal cells. Molecular dynamics simulations were performed to analyze molecular interactions between the screened compounds and the active residues of the enzyme. Herein, we report two natural compounds of inhibitory nature active against β-secretase enzyme of amyloidic pathway and are potent lead molecules against Alzheimer’s disease.

  8. Mode of action associated with development of hemangiosarcoma in mice given pregabalin and assessment of human relevance.

    Science.gov (United States)

    Criswell, Kay A; Cook, Jon C; Wojcinski, Zbigniew; Pegg, David; Herman, James; Wesche, David; Giddings, John; Brady, Joseph T; Anderson, Timothy

    2012-07-01

    Pregabalin increased the incidence of hemangiosarcomas in carcinogenicity studies of 2-year mice but was not tumorigenic in rats. Serum bicarbonate increased within 24 h of pregabalin administration in mice and rats. Rats compensated appropriately, but mice developed metabolic alkalosis and increased blood pH. Local tissue hypoxia and increased endothelial cell proliferation were also confirmed in mice alone. The combination of hypoxia and sustained increases in endothelial cell proliferation, angiogenic growth factors, dysregulated erythropoiesis, and macrophage activation is proposed as the key event in the mode of action (MOA) for hemangiosarcoma formation. Hemangiosarcomas occur spontaneously in untreated control mice but occur only rarely in humans. The International Programme on Chemical Safety and International Life Sciences Institute developed a Human Relevance Framework (HRF) analysis whereby presence or absence of key events can be used to assess human relevance. The HRF combines the MOA with an assessment of biologic plausibility in humans to assess human relevance. This manuscript compares the proposed MOA with Hill criteria, a component of the HRF, for strength, consistency, specificity, temporality, and dose response, with an assessment of key biomarkers in humans, species differences in response to disease conditions, and spontaneous incidence of hemangiosarcoma to evaluate human relevance. Lack of key biomarker events in the MOA in rats, monkeys, and humans supports a species-specific process and demonstrates that the tumor findings in mice are not relevant to humans at the clinical dose of pregabalin. Based on this collective dataset, clinical use of pregabalin would not pose an increased risk for hemangiosarcoma to humans.

  9. A Microplate Growth Inhibition Assay for Screening Bacteriocins against Listeria monocytogenes to Differentiate Their Mode-of-Action

    Directory of Open Access Journals (Sweden)

    Paul Priyesh Vijayakumar

    2015-06-01

    Full Text Available Lactic acid bacteria (LAB have historically been used in food fermentations to preserve foods and are generally-recognized-as-safe (GRAS by the FDA for use as food ingredients. In addition to lactic acid; some strains also produce bacteriocins that have been proposed for use as food preservatives. In this study we examined the inhibition of Listeria monocytogenes 39-2 by neutralized and non-neutralized bacteriocin preparations (Bac+ preps produced by Lactobacillus curvatus FS47; Lb. curvatus Beef3; Pediococcus acidilactici Bac3; Lactococcus lactis FLS1; Enterococcus faecium FS56-1; and Enterococcus thailandicus FS92. Activity differences between non-neutralized and neutralized Bac+ preps in agar spot assays could not readily be attributed to acid because a bacteriocin-negative control strain was not inhibitory to Listeria in these assays. When neutralized and non-neutralized Bac+ preps were used in microplate growth inhibition assays against L. monocytogenes 39-2 we observed some differences attributed to acid inhibition. A microplate growth inhibition assay was used to compare inhibitory reactions of wild-type and bacteriocin-resistant variants of L. monocytogenes to differentiate bacteriocins with different modes-of-action (MOA whereby curvaticins FS47 and Beef3, and pediocin Bac3 were categorized to be in MOA1; enterocins FS92 and FS56-1 in MOA2; and lacticin FLS1 in MOA3. The microplate bacteriocin MOA assay establishes a platform to evaluate the best combination of bacteriocin preparations for use in food applications as biopreservatives against L. monocytogenes.

  10. Mechanistic insights into mode of action of potent natural antagonists of BACE-1 for checking Alzheimer’s plaque pathology

    International Nuclear Information System (INIS)

    Dhanjal, Jaspreet Kaur; Goyal, Sukriti; Sharma, Sudhanshu; Hamid, Rabia; Grover, Abhinav

    2014-01-01

    Highlights: •Accumulation of Aβ plaques is one of the major pathology associated with Alzheimer’s disease. •Inhibition of β-Secretase or BACE-1 offers a viable prospect to check the growth of these plaques. •A large virtual dataset of natural compounds was screened against BACE-1. •Top two hits were analyzed for thermodynamic and structural stability using MD simulations. •Their detailed binding mode of actions were elucidated. -- Abstract: Alzheimer’s is a neurodegenerative disorder resulting in memory loss and decline in cognitive abilities. Accumulation of extracellular beta amyloidal plaques is one of the major pathology associated with this disease. β-Secretase or BACE-1 performs the initial and rate limiting step of amyloidic pathway in which 37–43 amino acid long peptides are generated which aggregate to form plaques. Inhibition of this enzyme offers a viable prospect to check the growth of these plaques. Numerous efforts have been made in recent years for the generation of BACE-1 inhibitors but many of them failed during the preclinical or clinical trials due to drug related or drug induced toxicity. In the present work, we have used computational methods to screen a large dataset of natural compounds to search for small molecules having BACE-1 inhibitory activity with low toxicity to normal cells. Molecular dynamics simulations were performed to analyze molecular interactions between the screened compounds and the active residues of the enzyme. Herein, we report two natural compounds of inhibitory nature active against β-secretase enzyme of amyloidic pathway and are potent lead molecules against Alzheimer’s disease

  11. Dopamine receptor antagonists as new mode-of-action insecticide leads for control of Aedes and Culex mosquito vectors.

    Science.gov (United States)

    Nuss, Andrew B; Ejendal, Karin F K; Doyle, Trevor B; Meyer, Jason M; Lang, Emma G; Watts, Val J; Hill, Catherine A

    2015-03-01

    New mode-of-action insecticides are sought to provide continued control of pesticide resistant arthropod vectors of neglected tropical diseases (NTDs). We previously identified antagonists of the AaDOP2 D1-like dopamine receptor (DAR) from the yellow fever mosquito, Aedes aegypti, with toxicity to Ae. aegypti larvae as leads for novel insecticides. To extend DAR-based insecticide discovery, we evaluated the molecular and pharmacological characteristics of an orthologous DAR target, CqDOP2, from Culex quinquefasciatus, the vector of lymphatic filariasis and West Nile virus. CqDOP2 has 94.7% amino acid identity to AaDOP2 and 28.3% identity to the human D1-like DAR, hD1. CqDOP2 and AaDOP2 exhibited similar pharmacological responses to biogenic amines and DAR antagonists in cell-based assays. The antagonists amitriptyline, amperozide, asenapine, chlorpromazine and doxepin were between 35 to 227-fold more selective at inhibiting the response of CqDOP2 and AaDOP2 in comparison to hD1. Antagonists were toxic to both C. quinquefasciatus and Ae. aegypti larvae, with LC50 values ranging from 41 to 208 μM 72 h post-exposure. Orthologous DOP2 receptors identified from the African malaria mosquito, Anopheles gambiae, the sand fly, Phlebotomus papatasi and the tsetse fly, Glossina morsitans, had high sequence similarity to CqDOP2 and AaDOP2. DAR antagonists represent a putative new insecticide class with activity against C. quinquefasciatus and Ae. aegypti, the two most important mosquito vectors of NTDs. There has been limited change in the sequence and pharmacological properties of the DOP2 DARs of these species since divergence of the tribes Culicini and Aedini. We identified antagonists selective for mosquito versus human DARs and observed a correlation between DAR pharmacology and the in vivo larval toxicity of antagonists. These data demonstrate that sequence similarity can be predictive of target potential. On this basis, we propose expanded insecticide discovery around

  12. Evaluation of genotoxic effects of surface waters using a battery of bioassays indicating different mode of action.

    Science.gov (United States)

    Han, Yingnan; Li, Na; Oda, Yoshimitsu; Ma, Mei; Rao, Kaifeng; Wang, Zijian; Jin, Wei; Hong, Gang; Li, Zhiguo; Luo, Yi

    2016-11-01

    With the burgeoning contamination of surface waters threatening human health, the genotoxic effects of surface waters have received much attention. Because mutagenic and carcinogenic compounds in water cause tumors by different mechanisms, a battery of bioassays that each indicate a different mode of action (MOA) is required to evaluate the genotoxic effects of contaminants in water samples. In this study, 15 water samples from two source water reservoirs and surrounding rivers in Shijiazhuang city of China were evaluated for genotoxic effects. Target chemical analyses of 14 genotoxic pollutants were performed according to the Environmental quality standards for surface water of China. Then, the in vitro cytokinesis-block micronucleus (CBMN) assay, based on a high-content screening technique, was used to detect the effect of chromosome damage. The SOS/umu test using strain TA1535/pSK1002 was used to detect effects on SOS repair of gene expression. Additionally, two other strains, NM2009 and NM3009, which are highly sensitive to aromatic amines and nitroarenes, respectively, were used in the SOS/umu test to avoid false negative results. In the water samples, only two of the genotoxic chemicals listed in the water standards were detected in a few samples, with concentrations that were below water quality standards. However, positive results for the CBMN assay were observed in two river samples, and positive results for the induction of umuC gene expression in TA1535/pSK1002 were observed in seven river samples. Moreover, positive results were observed for NM2009 with S9 and NM3009 without S9 in some samples that had negative results using the strain TA1535/pSK1002. Based on the results with NM2009 and NM3009, some unknown or undetected aromatic amines and nitroarenes were likely in the source water reservoirs and the surrounding rivers. Furthermore, these compounds were most likely the causative pollutants for the genotoxic effect of these water samples. Therefore

  13. Dopamine Receptor Antagonists as New Mode-of-Action Insecticide Leads for Control of Aedes and Culex Mosquito Vectors

    Science.gov (United States)

    Nuss, Andrew B.; Ejendal, Karin F. K.; Doyle, Trevor B.; Meyer, Jason M.; Lang, Emma G.; Watts, Val J.; Hill, Catherine A.

    2015-01-01

    Background New mode-of-action insecticides are sought to provide continued control of pesticide resistant arthropod vectors of neglected tropical diseases (NTDs). We previously identified antagonists of the AaDOP2 D1-like dopamine receptor (DAR) from the yellow fever mosquito, Aedes aegypti, with toxicity to Ae. aegypti larvae as leads for novel insecticides. To extend DAR-based insecticide discovery, we evaluated the molecular and pharmacological characteristics of an orthologous DAR target, CqDOP2, from Culex quinquefasciatus, the vector of lymphatic filariasis and West Nile virus. Methods/Results CqDOP2 has 94.7% amino acid identity to AaDOP2 and 28.3% identity to the human D1-like DAR, hD1. CqDOP2 and AaDOP2 exhibited similar pharmacological responses to biogenic amines and DAR antagonists in cell-based assays. The antagonists amitriptyline, amperozide, asenapine, chlorpromazine and doxepin were between 35 to 227-fold more selective at inhibiting the response of CqDOP2 and AaDOP2 in comparison to hD1. Antagonists were toxic to both C. quinquefasciatus and Ae. aegypti larvae, with LC50 values ranging from 41 to 208 μM 72 h post-exposure. Orthologous DOP2 receptors identified from the African malaria mosquito, Anopheles gambiae, the sand fly, Phlebotomus papatasi and the tsetse fly, Glossina morsitans, had high sequence similarity to CqDOP2 and AaDOP2. Conclusions DAR antagonists represent a putative new insecticide class with activity against C. quinquefasciatus and Ae. aegypti, the two most important mosquito vectors of NTDs. There has been limited change in the sequence and pharmacological properties of the DOP2 DARs of these species since divergence of the tribes Culicini and Aedini. We identified antagonists selective for mosquito versus human DARs and observed a correlation between DAR pharmacology and the in vivo larval toxicity of antagonists. These data demonstrate that sequence similarity can be predictive of target potential. On this basis, we propose

  14. Cytotoxicity and modes of action of five Cameroonian medicinal plants against multi-factorial drug resistance of tumor cells.

    Science.gov (United States)

    Kuete, Victor; Tankeo, Simplice B; Saeed, Mohamed E M; Wiench, Benjamin; Tane, Pierre; Efferth, Thomas

    2014-04-11

    Beilschmiedia acuta Kosterm, Clausena anisata (Willd) Hook, Fagara tessmannii Engl., Newbouldia laevis Seem., and Polyscias fulva (Hiern) Harms. are medicinal plants used in Cameroonian traditional medicine in the treatment of various types of cancers. The present study aims at investigating 11 methanolic extracts from the above Cameroonian medicinal plants on a panel of human cancer cell lines, including various drug-resistant phenotypes. Possible modes of action were analyzed for two extracts from Beilschmiedia acuta and Polyscia fulva and alpha-hederin, the representative constituent of Polyscia fulva. Cytotoxicity was determined using a resazurin assay. Cell cycle, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were measured by flow cytometry. Cellular response to alpha-hederin was investigated by a mRNA microarray approach. Prescreening of extracts (40µg/mL) showed that three of eleven plant extracts inhibited proliferation of CCRF-CEM cells by more than 50%, i.e. BAL (73.65%), the bark extract of Beilschmiedia acuta (78.67%) and PFR (68.72%). Subsequent investigations revealed IC50 values below or around 30µg/mL of BAL and PFR in 10 cell lines, including drug-resistant models, i.e. P-glycoprotein-overexpressing CEM/ADR5000, breast cancer resistance protein-transfected MDA-MB-231-BCRP, TP53 knockout cells (HCT116 p53(-/-)), and mutation-activated epidermal growth factor receptor-transfected U87MG.ΔEGFR cells. IC50 values below 5µg/mL of BAL were obtained for HCT116 (p53(-/-)) cells. IC50 values below 10µM of alpha-hederin were found for sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 cells. The BAL and PFR extracts induced cell cycle arrest between G0/G1 and S phases. PFR-induced apoptosis was associated with increased ROS generation and MMP breakdown. Microarray-based cluster analysis revealed a gene expression profile that predicted cellular response to alpha-hederin. BAL, PFL and alpha-hederin, an

  15. A Bayesian network model for predicting aquatic toxicity mode of action using two dimensional theoretical molecular descriptors

    Energy Technology Data Exchange (ETDEWEB)

    Carriger, John F. [U.S. Environmental Protection Agency, Office of Research and Development, Gulf Ecology Division, Gulf Breeze, FL, 32561 (United States); Martin, Todd M. [U.S. Environmental Protection Agency, Office of Research and Development, Sustainable Technology Division, Cincinnati, OH, 45220 (United States); Barron, Mace G., E-mail: barron.mace@epa.gov [U.S. Environmental Protection Agency, Office of Research and Development, Gulf Ecology Division, Gulf Breeze, FL, 32561 (United States)

    2016-11-15

    Highlights: • A Bayesian network was developed to classify chemical mode of action (MoA). • The network was based on the aquatic toxicity MoA for over 1000 chemicals. • A Markov blanket algorithm selected a subset of theoretical molecular descriptors. • Sensitivity analyses found influential descriptors for classifying the MoAs. • Overall precision of the Bayesian MoA classification model was 80%. - Abstract: The mode of toxic action (MoA) has been recognized as a key determinant of chemical toxicity, but development of predictive MoA classification models in aquatic toxicology has been limited. We developed a Bayesian network model to classify aquatic toxicity MoA using a recently published dataset containing over one thousand chemicals with MoA assignments for aquatic animal toxicity. Two dimensional theoretical chemical descriptors were generated for each chemical using the Toxicity Estimation Software Tool. The model was developed through augmented Markov blanket discovery from the dataset of 1098 chemicals with the MoA broad classifications as a target node. From cross validation, the overall precision for the model was 80.2%. The best precision was for the AChEI MoA (93.5%) where 257 chemicals out of 275 were correctly classified. Model precision was poorest for the reactivity MoA (48.5%) where 48 out of 99 reactive chemicals were correctly classified. Narcosis represented the largest class within the MoA dataset and had a precision and reliability of 80.0%, reflecting the global precision across all of the MoAs. False negatives for narcosis most often fell into electron transport inhibition, neurotoxicity or reactivity MoAs. False negatives for all other MoAs were most often narcosis. A probabilistic sensitivity analysis was undertaken for each MoA to examine the sensitivity to individual and multiple descriptor findings. The results show that the Markov blanket of a structurally complex dataset can simplify analysis and interpretation by

  16. Structural modification of resveratrol leads to increased anti-tumor activity, but causes profound changes in the mode of action

    Energy Technology Data Exchange (ETDEWEB)

    Scherzberg, Maria-Christina; Kiehl, Andreas; Zivkovic, Aleksandra; Stark, Holger [Institute of Pharmaceutical Chemistry, Biozentrum, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main (Germany); Stein, Jürgen [Institute of Pharmaceutical Chemistry, Biozentrum, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main (Germany); Department of Internal Medicine, Sachsenhausen Hospital, Frankfurt am Main (Germany); Fürst, Robert [Institute of Pharmaceutical Biology, Biozentrum, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main (Germany); Steinhilber, Dieter [Institute of Pharmaceutical Chemistry, Biozentrum, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main (Germany); Ulrich-Rückert, Sandra, E-mail: sandra.ulrich@em.uni-frankfurt.de [Institute of Pharmaceutical Chemistry, Biozentrum, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main (Germany)

    2015-08-15

    (Z)-3,5,4′-Trimethoxystilbene (Z-TMS) is a resveratrol analog with increased antiproliferative activity towards a number of cancer cell lines compared to resveratrol, which has been shown to inhibit tubulin polymerization in vitro. The purpose of this study was to investigate if Z-TMS still shows potential for the prevention of metabolic diseases as known for resveratrol. Cell growth inhibition was determined with IC{sub 50} values for Z-TMS between 0.115 μM and 0.473 μM (resveratrol: 110.7 μM to 190.2 μM). Flow cytometric analysis revealed a G{sub 2}/M arrest after Z-TMS treatment, whereas resveratrol caused S phase arrest. Furthermore, Z-TMS was shown to impair microtubule polymerization. Beneficial effects on lipid accumulation were observed for resveratrol, but not for Z-TMS in an in vitro steatosis model. (E)-Resveratrol was confirmed to elevate cAMP levels, and knockdown of AMPK attenuated the antiproliferative activity, while Z-TMS did not show significant effects in these experiments. SIRT1 and AMPK activities were further measured indirectly via induction of the target gene small heterodimer partner (SHP). Thereby, (E)-resveratrol, but not Z-TMS, showed potent induction of SHP mRNA levels in an AMPK- and SIRT1-dependent manner, as confirmed by knockdown experiments. We provide evidence that Z-TMS does not show beneficial metabolic effects, probably due to loss of activity towards resveratrol target genes. Moreover, our data support previous findings that Z-TMS acts as an inhibitor of tubulin polymerization. These findings confirm that the methylation of resveratrol leads to profound changes in the mode of action, which should be taken into consideration when conducting lead structure optimization approaches. - Highlights: • Methylation of resveratrol leads to profound changes in biologic activity. • Z-TMS does not prevent hepatic steatosis, but inhibits tubulin polymerization. • Resveratrol analog Z-TMS does not influence known targets like

  17. Structure-activity relationships of the antimicrobial peptide arasin 1 - and mode of action studies of the N-terminal, proline-rich region.

    Directory of Open Access Journals (Sweden)

    Victoria S Paulsen

    Full Text Available Arasin 1 is a 37 amino acid long proline-rich antimicrobial peptide isolated from the spider crab, Hyas araneus. In this work the active region of arasin 1 was identified through structure-activity studies using different peptide fragments derived from the arasin 1 sequence. The pharmacophore was found to be located in the proline/arginine-rich NH(2 terminus of the peptide and the fragment arasin 1(1-23 was almost equally active to the full length peptide. Arasin 1 and its active fragment arasin 1(1-23 were shown to be non-toxic to human red blood cells and arasin 1(1-23 was able to bind chitin, a component of fungal cell walls and the crustacean shell. The mode of action of the fully active N-terminal arasin 1(1-23 was explored through killing kinetic and membrane permeabilization studies. At the minimal inhibitory concentration (MIC, arasin 1(1-23 was not bactericidal and had no membrane disruptive effect. In contrast, at concentrations of 5×MIC and above it was bactericidal and interfered with membrane integrity. We conclude that arasin 1(1-23 has a different mode of action than lytic peptides, like cecropin P1. Thus, we suggest a dual mode of action for arasin 1(1-23 involving membrane disruption at peptide concentrations above MIC, and an alternative mechanism of action, possibly involving intracellular targets, at MIC.

  18. Thymus vulgaris essential oil and thymol against Alternaria alternata (Fr.) Keissler: effects on growth, viability, early infection and cellular mode of action.

    Science.gov (United States)

    Perina, Fabiano J; Amaral, Douglas C; Fernandes, Rafael S; Labory, Claudia Rg; Teixeira, Glauco A; Alves, Eduardo

    2015-10-01

    In initial assays, Thymus vulgaris essential oil (TEO) has demonstrated activity against several plant-pathogenic fungi and has reduced the fungal diseases to levels comparable with commercial fungicides. Thus, the goal of this work was to identify the mode of action in fungi of TEO and its major compound thymol (TOH) at the cellular level using an ultrastructure approach. TEO from leaves and TOH had minimum inhibitory concentrations (MICs) of 500 and 250 µg mL(-1) respectively against A. alternata; under the same conditions, MIC for a commercial fungicide was 1250 µg mL(-1) . Ultrastructure analysis showed that TOH phenolic substance prevented fungal growth, reduced fungal viability and prevented the penetration in fruits by a cell wall/plasma membrane interference mode of action with organelles targeted for destruction in the cytoplasm. Such mode of action differs from protective and preventive-curative commercial fungicides used as pattern control. These findings suggest that TOH was responsible for the antifungal activity of TEO. Therefore, both the essential oil and its major substance have potential for use in the development of new phenolic structures and analogues to control Alternaria brown spot disease caused by Alternaria alternata. © 2014 Society of Chemical Industry.

  19. Raman spectroscopy, electronic microscopy and SPME-GC-MS to elucidate the mode of action of a new antimicrobial food packaging material.

    Science.gov (United States)

    Clemente, Isabel; Aznar, Margarita; Salafranca, Jesús; Nerín, Cristina

    2017-02-01

    One critical challenge when developing a new antimicrobial packaging material is to demonstrate the mode of action of the antimicrobials incorporated into the packaging. For this task, several analytical techniques as well as microbiology are required. In this work, the antimicrobial properties of benzyl isothiocyanate, allyl isothiocyanate and essential oils of cinnamon and oregano against several moulds and bacteria have been evaluated. Benzyl isothiocyanate showed the highest antimicrobial activity and it was selected for developing the new active packaging material. Scanning electron microscopy and Raman spectroscopy were successfully used to demonstrate the mode of action of benzyl isothiocyanate on Escherichia coli. Bacteria exhibited external modifications such as oval shape and the presence of septum surface, but they did not show any disruption or membrane damage. To provide data on the in vitro action of benzyl isothiocyanate and the presence of inhibition halos, the transfer mechanism to the cells was assessed using solid-phase microextraction-gas chromatography-mass spectrometry. Based on the transfer system, action mechanism and its stronger antimicrobial activity, benzyl isothiocyanate was incorporated to two kinds of antimicrobial labels. The labels were stable and active for 140 days against two mould producers of ochratoxin A; Penicillium verrucosum is more sensitive than Aspergillus ochraceus. Details about the analytical techniques and the results obtained are shown and discussed. Graphical Abstract Antimicrobial evaluation of pure compounds, incorporation in the packaging and study for mode of action on S. coli by Raman, SEM and SPME-GC-MS.

  20. The genus Macrostemum Kolenati 1859 (Trichoptera: Hydropsychidae) in the Neotropical Region: Description of two new species, taxonomic notes, distributional records and key to males.

    Science.gov (United States)

    França, Diogo; Paprocki, Henrique; Calor, Adolfo R

    2013-01-01

    The genus Macrostemum Kolenati contains 105. described species, with 15 valid species in the Neotropical region. The Adults are recognized principally by wing membranes strongly marked with dark and light colors. The Neotropical species Of Macrostemum were described based on the wing colors patterns and body morphology. In this paper we present a taxonomic study of the Neotropical species, descriptions of two new species from Brazil, distributional records and a key to males. The male of Macrostemum negrense Flint 1978 is described for the first time, Names of three Neotropical species, M. ramosum (Navás 1916), M. trigramma (Navás 1916), and M. triste (Navás 1916) are designated nomina dubia.

  1. New taxonomic and distributional information on hermit crabs (Crustacea: Anomura: Paguroidea) from the Gulf of Mexico, Caribbean Sea, and Atlantic coast of South America.

    Science.gov (United States)

    Lemaitre, Rafael; Tavares, Marcos

    2015-08-04

    A collection of Paguroidea recently obtained during deep-water expeditions along the coast of Brazil, forms the basis of this report. Of the 14 species reported from Brazil, 11 represent range extensions to the south, and one, Michelopagurus atlanticus (Bouvier, 1922), is a first record for the western Atlantic. The specimens were compared with types and western Atlantic materials deposited in various major museums. A diagnosis and illustrations are presented for each of seven species found to be poorly or insufficiently known. New material and information is reported for two additional species that occur in Brazil but not found in the recent deep-water collections: Clibanarius symmetricus (Randall, 1840) and Mixtopagurus paradoxus A. Milne-Edwards, 1880. Remarkable and unique color photographs of live or fresh specimens of Allodardanus bredini Haig & Provenzano, 1965, Bathynarius anomalus (A. Milne-Edwards & Bouvier, 1893), Pylopagurus discoidalis (A. Milne-Edwards, 1880), Paguristes spinipes A. Milne-Edwards, 1880, Parapagurus pilosimanus Smith, 1876, and P. alaminos Lemaitre, 1986, are presented. A review of published records and museum collections of the terrestrial Coenobita clypeatus (Fabricius, 1787), has shown that the southern range limit of this species does not extend beyond the southern Caribbean and Trinidad and Tobago, and thus does not occur on the Brazilian coast as previously believed. A distribution map of C. clypeatus is provided based on specimens in the collections of the National Museum of Natural History, Smithsonian Institution. New distribution records in the Gulf of Mexico and southern Caribbean, and morphological information, are included for Pagurus rotundimanus Wass, 1963, a species originally described from the Florida Keys but rarely reported since. Relevant remarks on the taxonomy, morphology, and distribution of all these species are included. The revised list of Paguroidea known from Brazil is updated, and now includes a total of

  2. Mode of Action: Oxalate Crystal-Induced Renal Tubule Degeneration and Glycolic Acid-Induced Dysmorphogenesis—Renal and Developmental Effects of Ethylene Glycol

    Energy Technology Data Exchange (ETDEWEB)

    Corley, Rick A.; Meek, M E.; Carney, E W.

    2005-10-01

    Ethylene glycol can cause both renal and developmental toxicity, with metabolism playing a key role in the mode of action (MOA) for each form of toxicity. Renal toxicity is ascribed to the terminal metabolite oxalic acid, which precipitates in the kidney in the form of calcium oxalate crystals and is believed to cause physical damage to the renal tubules. The human relevance of the renal toxicity of ethylene glycol is indicated by the similarity between animals and humans of metabolic pathways, the observation of renal oxalate crystals in toxicity studies in experimental animals and human poisonings, and cases of human kidney and bladder stones related to dietary oxalates and oxalate precursors. High-dose gavage exposures to ethylene glycol also cause axial skeletal defects in rodents (but not rabbits), with the intermediary metabolite, glycolic acid, identified as the causative agent. However, the mechanism by which glycolic acid perturbs development has not been investigated sufficiently to develop a plausible hypothesis of mode of action, nor have any cases of ethylene glycol-induced developmental effects been reported in humans. Given this, and the variations in sensitivity between animal species in response, the relevance to humans of ethylene glycol-induced developmental toxicity in animals is unknown at this time.

  3. Biological control of the cucurbit powdery mildew pathogen Podosphaera xanthii by means of the epiphytic fungus Pseudozyma aphidis and parasitism as a mode of action

    Directory of Open Access Journals (Sweden)

    Aviva eGafni

    2015-03-01

    Full Text Available Epiphytic yeasts, which colonize plant surfaces, may possess activity that can be harnessed to help plants defend themselves against various pathogens. Due to their unique characteristics, epiphytic yeasts belonging to the genus Pseudozyma hold great potential for use as biocontrol agents. We identified a unique, biologically active isolate of the epiphytic yeast Pseudozyma aphidis that is capable of inhibiting Botrytis cinerea via a dual mode of action, namely induced resistance and antibiosis. Here, we show that strain L12 of P. aphidis can reduce the severity of powdery mildew caused by Podosphaera xanthii on cucumber plants with an efficacy of 75%. Confocal and scanning electron microscopy analyses demonstrated P. aphidis proliferation on infected tissue and its production of long hyphae that parasitize the powdery mildew hyphae and spores as an ectoparasite. We also show that crude extract of P. aphidis metabolites can inhibit P. xanthii spore germination in planta. Our results suggest that in addition to its antibiosis mode of action, P. aphidis may also act as an ectoparasite on P. xanthii. These results indicate that P. aphidis strain L12 has the potential to control powdery mildew.

  4. Partial Purification and Characterization of the Mode of Action of Enterocin S37: A Bacteriocin Produced by Enterococcus faecalis S37 Isolated from Poultry Feces

    Directory of Open Access Journals (Sweden)

    Y. Belguesmia

    2010-01-01

    Full Text Available The aim of this research was to purify and characterize the mode of action of enterocin S37, a bacteriocin produced by Enterococcus faecalis S37, a strain recently isolated from the chicken feces. Enterocin S37 has a molecular weight comprised between 4 and 5 kDa. It remained active after 1 h at 80oC and at pH values ranging from 4.0 to 9.0. Furthermore, cell-free supernatant of Enterococcus faecalis S37 and purified enterocin S37 were active against Gram-positive bacteria including Listeria monocytogenes EGDe, L. innocua F, Enterococcus faecalis JH2-2, and Lactobacillus brevis F145. The purification of enterocin S37 was performed by ammonium sulfate precipitation followed up by hydrophobic-interaction chromatography procedures. Treatment of enterocin S37 with proteinase K, -chymotrypsin, and papain confirmed its proteinaceous nature, while its treatment with lysozyme and lipase resulted in no alteration of activity. Enterocin S37 is hydrophobic, anti-Listeria and likely acting by depletion of intracellular K+ ions upon action on KATP channels. This study contributed to gain more insights into the mode of action of enterocins.

  5. The economic importance of acaricides in the control of phytophagous mites and an update on recent acaricide mode of action research.

    Science.gov (United States)

    Van Leeuwen, Thomas; Tirry, Luc; Yamamoto, Atsushi; Nauen, Ralf; Dermauw, Wannes

    2015-06-01

    Acaricides are one of the cornerstones of an efficient control program for phytophagous mites. An analysis of the global acaricide market reveals that spider mites such as Tetranychus urticae, Panonychus citri and Panonychus ulmi are by far the most economically important species, representing more than 80% of the market. Other relevant mite groups are false spider mites (mainly Brevipalpus), rust and gall mites and tarsonemid mites. Acaricides are most frequently used in vegetables and fruits (74% of the market), including grape vines and citrus. However, their use is increasing in major crops where spider mites are becoming more important, such as soybean, cotton and corn. As revealed by a detailed case study of the Japanese market, major shifts in acaricide use are partially driven by resistance development and the commercial availability of compounds with novel mode of action. The importance of the latter cannot be underestimated, although some compounds are successfully used for more than 30 years. A review of recent developments in mode of action research is presented, as such knowledge is important for devising resistance management programs. This includes spirocyclic keto-enols as inhibitors of acetyl-CoA carboxylase, the carbazate bifenazate as a mitochondrial complex III inhibitor, a novel class of complex II inhibitors, and the mite growth inhibitors hexythiazox, clofentezine and etoxazole that interact with chitin synthase I. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Insecticidal genes of Yersinia spp.: taxonomical distribution, contribution to toxicity towards Manduca sexta and Galleria mellonella, and evolution

    Directory of Open Access Journals (Sweden)

    Schachtner Joachim

    2008-12-01

    Full Text Available Abstract Background Toxin complex (Tc proteins termed TcaABC, TcdAB, and TccABC with insecticidal activity are present in a variety of bacteria including the yersiniae. Results The tc gene sequences of thirteen Yersinia strains were compared, revealing a high degree of gene order conservation, but also remarkable differences with respect to pseudogenes, sequence variability and gene duplications. Outside the tc pathogenicity island (tc-PAIYe of Y. enterocolitica strain W22703, a pseudogene (tccC2'/3' encoding proteins with homology to TccC and similarity to tyrosine phosphatases at its C-terminus was identified. PCR analysis revealed the presence of the tc-PAIYe and of tccC2'/3'-homologues in all biotype 2–5 strains tested, and their absence in most representatives of biotypes 1A and 1B. Phylogenetic analysis of 39 TccC sequences indicates the presence of the tc-PAIYe in an ancestor of Yersinia. Oral uptake experiments with Manduca sexta revealed a higher larvae lethality of Yersinia strains harbouring the tc-PAIYe in comparison to strains lacking this island. Following subcutaneous infection of Galleria mellonella larvae with five non-human pathogenic Yersinia spp. and four Y. enterocolitica strains, we observed a remarkable variability of their insecticidal activity ranging from 20% (Y. kristensenii to 90% (Y. enterocolitica strain 2594 dead larvae after five days. Strain W22703 and its tcaA deletion mutant did not exhibit a significantly different toxicity towards G. mellonella. These data confirm a role of TcaA upon oral uptake only, and suggest the presence of further insecticidal determinants in Yersinia strains formerly unknown to kill insects. Conclusion This study investigated the tc gene distribution among yersiniae and the phylogenetic relationship between TccC proteins, thus contributing novel aspects to the current discussion about the evolution of insecticidal toxins in the genus Yersinia. The toxic potential of several Yersinia

  7. Diversidade taxonômica e distribuição geográfica das Orchidaceae brasileiras Taxonomic diversity and geographic distribution of the Brazilian Orchidaceae

    Directory of Open Access Journals (Sweden)

    Fábio de Barros

    1990-07-01

    Full Text Available Orchidaceae é uma das maiores famílias do Reino Vegetal, e sua distribuição geográfica obedece a limites definidos já a nivel de sub-famílias. O genero Laelia, com 7 seções das quais 5 ocorrentes no Brasil, apresenta características evolutivas interessantes, principalmente a sect. Parviflorae, que ocorre predominantemente em Minas Gerais e que representa um exemplo de "evolução explosiva" ainda em andamento. Os tratamentos taxonómicos dados a cada diferente grupo dentro da família não se apresentam uniformes, o que leva à aceitação de um grande número de gêneros pequenos em alguns grupos e de poucos gêneros grandes e complexos, em outros grupos.Orchidaceae is one of the largest plant families, and each of its subfamilies have a delimited distribution. The genus Laelia, with 7 subsections, 5 of which occuring in Brazil, shows interestingly evolutionary characteristics. Laelia sect. Parviflorae, which occurs mainly in Minas Gerais (Brazil is an example of "explosive evolution" still in process. The taxonomic treatment of the orchid family is not uniform from taxa to taxa which leads to many small genera in some groups and few large genera in some other groups.

  8. Identifying the Enzymatic Mode of Action for Cellulase Enzymes by Means of Docking Calculations and a Machine Learning Algorithm

    Directory of Open Access Journals (Sweden)

    Somisetti V. Sambasivarao

    2014-01-01

    Full Text Available Docking calculations have been conducted on 36 cellulase enzymes and the results were evaluated by a machine learning algorithm to determine the nature of the enzyme (i.e. endo- or exo- enzymatic activity. The docking calculations have also been used to identify crucial substrate-enzyme interactions, and establish structure-function relationships. The use of carboxymethyl cellulose as a docking substrate is found to correctly identify the endo- or exo- behavior of cellulase enzymes with 92% accuracy while cellobiose docking calculations resulted in an 86% predictive accuracy. The binding distributions for cellobiose have been classified into two distinct types; distributions with a single maximum or distributions with a bi-modal structure. It is found that the uni-modal distributions correspond to exo- type enzyme while a bi-modal substrate docking distribution corresponds to endo- type enzyme. These results indicate that the use of docking calculations and machine learning algorithms are a fast and computationally inexpensive method for predicting if a cellulase enzyme possesses primarily endo- or exo- type behavior, while also revealing critical enzyme-substrate interactions.

  9. Use of electroencephalography (EEG) to assess CNS changes produced by pesticides with different modes of action: Effects of permethrin, deltamethrin, fipronil, imidacloprid, carbaryl, and triadimefon

    Energy Technology Data Exchange (ETDEWEB)

    Freeborn, Danielle L., E-mail: Freeborn.danielle@epa.gov; McDaniel, Katherine L., E-mail: McDaniel.kathy@epa.gov; Moser, Virginia C., E-mail: Moser.ginger@epa.gov; Herr, David W., E-mail: Herr.david@epa.gov

    2015-01-15

    The electroencephalogram (EEG) is an apical measure, capable of detecting changes in brain neuronal activity produced by internal or external stimuli. We assessed whether pesticides with different modes of action produced different changes in the EEG of adult male Long–Evans rats. The EEG was recorded using two montages (visual cortex referenced to the cerebellum and to the frontal cortex) in unrestrained rats at the time of peak behavioral effects. Pesticides included: permethrin and deltamethrin (Type I and Type II pyrethroids; 2 h), fipronil (single and repeated doses; phenylpyrazole; 6 h), imidacloprid (neonicotinoid; 2 h), carbaryl (carbamate; 0.5 h), and triadimefon (triazole; 1 h), using dosages that produced approximately an ED{sub 30} or an ED{sub 50}–ED{sub 80} change in motor activity. Permethrin (43, 100 mg/kg) increased amplitudes or areas (delta, alpha, or gamma bands) in the EEG. Deltamethrin (2.5, 5.5 mg/kg) reduced the amplitudes or areas of the delta, theta, alpha, beta, and gamma bands, but the changes were not dose-related. A single treatment with fipronil (25, 50 mg/kg, but not 5, 10 mg/kg) decreased gamma band area. Additional changes in the delta, theta, and gamma bands were observed when fipronil (5, 10 mg/kg) was administered for 14 days. Imidacloprid (50, 100 mg/kg) did not alter the EEG. Carbaryl (10, 50 mg/kg) decreased theta area, and decreased delta and increased beta frequency. Triadimefon (75, 150 mg/kg) produced minimal changes in the EEG. The results show that the EEG is affected differently by approximately equipotent doses of pesticides with different modes of action. - Highlights: • Pesticides with different modes of action have different effects on in vivo rodent EEG. • The EEG was also changed differently after single vs. repeated treatment with fipronil. • The data suggest that EEG may be used as an apical measure for detecting chemical effects on the central nervous system.

  10. Southern distributional limits of Meliponini bees (Hymenoptera, Apidae) in the Neotropics: taxonomic notes and distribution of Plebeia droryana and P. emerinoides in Argentina.

    Science.gov (United States)

    Roig-Alsina, Arturo; Alvarez, Leopoldo J

    2017-03-19

    The southern distribution of stingless bees in the Neotropics reaches the province of Buenos Aires, Argentina, up to 34°51' S in latitude, where two species of Plebeia are found on the west margin of the Río de La Plata: P. emerinoides (Silvestri), and P. droryana (Friese). In this area some relicts of gallery forest occur and the climate is moderated by the large water mass of the river. The taxonomy of both species is discussed. Diagnoses, updated distribution, and illustrations of some morphological features are given for both species.

  11. Diuron-induced rat urinary bladder carcinogenesis: mode of action and human relevance evaluations using the International Programme on Chemical Safety framework.

    Science.gov (United States)

    Da Rocha, Mitscheli Sanches; Arnold, Lora L; De Oliveira, Maria Luiza Cotrim Sartor; Catalano, Shadia M Ihlaseh; Cardoso, Ana Paula Ferragut; Pontes, Merielen G N; Ferrucio, Bianca; Dodmane, Puttappa R; Cohen, Samuel M; De Camargo, João Lauro V

    2014-05-01

    Diuron, a high volume substituted urea herbicide, induced high incidences of urinary bladder carcinomas and low incidences of kidney pelvis papillomas and carcinomas in rats exposed to high doses (2500 ppm) in a 2-year bioassay. Diuron is registered for both occupational and residential uses and is used worldwide for more than 30 different crops. The proposed rat urothelial mode of action (MOA) for this herbicide consists of metabolic activation to metabolites that are excreted and concentrated in the urine, leading to cytotoxicity, urothelial cell necrosis and exfoliation, regenerative hyperplasia, and eventually tumors. We show evidence for this MOA for diuron using the International Programme on Chemical Safety (IPCS) conceptual framework for evaluating an MOA for chemical carcinogens, and the United States Environmental Protection Agency (USEPA) and IPCS framework for assessing human relevance.

  12. Physiology of inactivation of microbial cells by near-ultraviolet light: mode of action and application for the enrichment of mutants of Escherichia coli and saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Peters, J.

    1976-01-01

    The mode of action of near-ultraviolet (NUV) light was studied in Escherichia coli. NUV light (maximum emission at 365 nm) caused the photodestruction of ribonucleoside diphosphate (RDP) reductase activity in vivo. Evidence was presented for a model suggesting that the loss of RDP-reductase resulted in a metabolic state analogous to that produced during starvation for thymine. Some important properties of cells irradiated by NUV light, cell death, loss of the ability to support the replication of DNA phages and a delay in the onset of cell division in sublethally irradiated cells, were accounted for in terms of photoinactivation of RDP-reductase. Conditions were described under which NUV light was an effective counterselective agent for the enrichment of mutants of Escherichia coli and Saccharomyces cerevisiae

  13. Probable neuro sexual mode of action of Casimiroa edulis seed extract versus [correction of verses] sildenafil citrate (Viagra(tm)) on mating behavior in normal male rats.

    Science.gov (United States)

    Ali, Syed Tabrez; Rakkah, Nabeeh I

    2008-01-01

    The present study deals with the aphrodisiac actions of the aqueous extract of the seeds of the hypotensive plant Casimiroa edulis on the sexual behavior of normal male rats. In this investigation 30 healthy male Wister strain white albino rats showing the brisk sexual activity age 15 weeks, weighing 400-450 grams were included. Female rats were artificially brought into estrous by hormonal treatment. Receptivity was checked by exposing them to the male rats and the most receptive females were selected for the stud The mating responses including Mounting Frequency (MF), Intromission Frequency (IF), Mounting Latency (ML), Intromission Latency (IL), Ejaculatory Latency in first and second series (EL1 and EL2) and Post Ejaculatory Interval (PEI) were recorded after treating the animals with 250 mg/kg casimiroa edulis extract (test reference) and 5 mg/kg sildenafil citrate (standard reference) respectively orally per day for 7 days. Both the groups exhibited a significant increase in Mounting Frequency, Intromission Frequency, and first and second ejaculatory latencies, where as Mounting and Intromission latencies and the Post Ejaculatory Interval showed a significant reduction than the controls. Although a similar pattern of mating behavior was observed among the test and the standard groups, however in all the cases as expected, sildenafil produced greater activity than the casimiroa edulis extract. These results suggest the possibility of a similar mode of action of casimiroa edulis and sildenafil citrate on mating behavior in these animals. Our work reported in this research thus provide preliminary evidence that the aqueous seed extract of casimiroa edulis possesses alphrodisiac activity and may be used as an alternative drug therapy to restore sexual functions probably via a neurogenic mode of action.

  14. Cogena, a novel tool for co-expressed gene-set enrichment analysis, applied to drug repositioning and drug mode of action discovery.

    Science.gov (United States)

    Jia, Zhilong; Liu, Ying; Guan, Naiyang; Bo, Xiaochen; Luo, Zhigang; Barnes, Michael R

    2016-05-27

    Drug repositioning, finding new indications for existing drugs, has gained much recent attention as a potentially efficient and economical strategy for accelerating new therapies into the clinic. Although improvement in the sensitivity of computational drug repositioning methods has identified numerous credible repositioning opportunities, few have been progressed. Arguably the "black box" nature of drug action in a new indication is one of the main blocks to progression, highlighting the need for methods that inform on the broader target mechanism in the disease context. We demonstrate that the analysis of co-expressed genes may be a critical first step towards illumination of both disease pathology and mode of drug action. We achieve this using a novel framework, co-expressed gene-set enrichment analysis (cogena) for co-expression analysis of gene expression signatures and gene set enrichment analysis of co-expressed genes. The cogena framework enables simultaneous, pathway driven, disease and drug repositioning analysis. Cogena can be used to illuminate coordinated changes within disease transcriptomes and identify drugs acting mechanistically within this framework. We illustrate this using a psoriatic skin transcriptome, as an exemplar, and recover two widely used Psoriasis drugs (Methotrexate and Ciclosporin) with distinct modes of action. Cogena out-performs the results of Connectivity Map and NFFinder webservers in similar disease transcriptome analyses. Furthermore, we investigated the literature support for the other top-ranked compounds to treat psoriasis and showed how the outputs of cogena analysis can contribute new insight to support the progression of drugs into the clinic. We have made cogena freely available within Bioconductor or https://github.com/zhilongjia/cogena . In conclusion, by targeting co-expressed genes within disease transcriptomes, cogena offers novel biological insight, which can be effectively harnessed for drug discovery and

  15. Inhibitory effect and mode of action of chitosan solution against rice bacterial brown stripe pathogen Acidovorax avenae subsp. avenae RS-1.

    Science.gov (United States)

    Yang, Chunlan; Li, Bin; Ge, Mengyu; Zhou, Kaile; Wang, Yanli; Luo, Ju; Ibrahim, Muhammad; Xie, Guanlin; Sun, Guochang

    2014-06-04

    Inhibitory effect and mode of action of chitosan solution against rice bacterial brown stripe pathogen Acidovorax avenae subsp. avenae (Aaa) strain RS-1 was examined in this study. Result from this study indicated that chitosan solutions at 0.10, 0.20, and 0.40mg/mL inhibited the in vitro growth of Aaa strain RS-1, and in general the inhibitory efficiency increased with the increase of both chitosan concentration and the incubation time. Antibacterial activity of chitosan in this study may be mainly due to the damage of cell membrane, which was evidenced by both the cell lysis observed by transmission electron microscopy, and the increased release of cell materials based on the measurement of cell membrane integrity. Furthermore, chitosan solutions at concentrations of 0.1, 0.2, and 0.4mg/mL markedly inhibited bacterial biofilm formation compared to the control, and the inhibitory effect increased with the increase of chitosan concentration. In addition, quantitative real-time PCR of the 10 secretion system related genes revealed the differential expression of genes in particular ompA/motB, emphasizing the importance of this gene in the response of Aaa strain RS-1 to chitosan stress. These results indicated that the antibacterial mode of action of chitosan may be mainly due to membrane disruption and lysis, reduction of biofilm formation, and gene expression change. Overall, the results clearly indicated that chitosan had the potential to control bacterial brown stripe of rice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Coriandrum sativum L. (Coriander) essential oil: antifungal activity and mode of action on Candida spp., and molecular targets affected in human whole-genome expression.

    Science.gov (United States)

    Freires, Irlan de Almeida; Murata, Ramiro Mendonça; Furletti, Vivian Fernandes; Sartoratto, Adilson; Alencar, Severino Matias de; Figueira, Glyn Mara; de Oliveira Rodrigues, Janaina Aparecida; Duarte, Marta Cristina Teixeira; Rosalen, Pedro Luiz

    2014-01-01

    Oral candidiasis is an opportunistic fungal infection of the oral cavity with increasingly worldwide prevalence and incidence rates. Novel specifically-targeted strategies to manage this ailment have been proposed using essential oils (EO) known to have antifungal properties. In this study, we aim to investigate the antifungal activity and mode of action of the EO from Coriandrum sativum L. (coriander) leaves on Candida spp. In addition, we detected the molecular targets affected in whole-genome expression in human cells. The EO phytochemical profile indicates monoterpenes and sesquiterpenes as major components, which are likely to negatively impact the viability of yeast cells. There seems to be a synergistic activity of the EO chemical compounds as their isolation into fractions led to a decreased antimicrobial effect. C. sativum EO may bind to membrane ergosterol, increasing ionic permeability and causing membrane damage leading to cell death, but it does not act on cell wall biosynthesis-related pathways. This mode of action is illustrated by photomicrographs showing disruption in biofilm integrity caused by the EO at varied concentrations. The EO also inhibited Candida biofilm adherence to a polystyrene substrate at low concentrations, and decreased the proteolytic activity of Candida albicans at minimum inhibitory concentration. Finally, the EO and its selected active fraction had low cytotoxicity on human cells, with putative mechanisms affecting gene expression in pathways involving chemokines and MAP-kinase (proliferation/apoptosis), as well as adhesion proteins. These findings highlight the potential antifungal activity of the EO from C. sativum leaves and suggest avenues for future translational toxicological research.

  17. Mode of action human relevance (species concordance) framework: Evolution of the Bradford Hill considerations and comparative analysis of weight of evidence

    Science.gov (United States)

    Meek, M E (Bette); Palermo, Christine M; Bachman, Ammie N; North, Colin M; Jeffrey Lewis, R

    2014-01-01

    The mode of action human relevance (MOA/HR) framework increases transparency in systematically considering data on MOA for end (adverse) effects and their relevance to humans. This framework continues to evolve as experience increases in its application. Though the MOA/HR framework is not designed to address the question of “how much information is enough” to support a hypothesized MOA in animals or its relevance to humans, its organizing construct has potential value in considering relative weight of evidence (WOE) among different cases and hypothesized MOA(s). This context is explored based on MOA analyses in published assessments to illustrate the relative extent of supporting data and their implications for dose–response analysis and involved comparisons for chemical assessments on trichloropropane, and carbon tetrachloride with several hypothesized MOA(s) for cancer. The WOE for each hypothesized MOA was summarized in narrative tables based on comparison and contrast of the extent and nature of the supporting database versus potentially inconsistent or missing information. The comparison was based on evolved Bradford Hill considerations rank ordered to reflect their relative contribution to WOE determinations of MOA taking into account increasing experience in their application internationally. This clarification of considerations for WOE determinations as a basis for comparative analysis is anticipated to contribute to increasing consistency in the application of MOA/HR analysis and potentially, transparency in separating science judgment from public policy considerations in regulatory risk assessment. Copyright © 2014. The Authors. Journal of Applied Toxicology Published by John Wiley & Sons Ltd. The potential value of the mode of action (MOA)/human relevance (species concordance) framework in considering relative weight of evidence (WOE) amongst different cases and hypothesized MOA(s) is explored based on the content of several published assessments

  18. Comparative Effect of Three Neurotoxic Insecticides With Different Modes of Action on Adult Males and Females of Three Tortricid Moth Pests.

    Science.gov (United States)

    Navarro-Roldán, Miguel A; Avilla, Jesús; Bosch, Dolors; Valls, Joan; Gemeno, César

    2017-08-01

    Insecticides are the dominant pest management method in fruit and vegetable crops worldwide owing to their quick effect, low cost, and relatively easy application, but they bear negative effects on human health and the environment. Insecticide mode of action (MoA), target species, and sex are variables that could affect insecticide-induced mortality. We recorded the mortality caused by three neurotoxic insecticides with different modes of action (chlorpyrifos [organophosphate, acetylcholinesterase inhibitor], λ-cyhalothrin [pyrethroid, sodium channel modulator], and thiacloprid [neonicotinoid, nicotinic acetylcholinesterase receptor agonist]) applied topically to adult males and females of three economically important tortricid species [Cydia pomonella (L.), Grapholita molesta (Busck), and Lobesia botrana (Denis & Schiffermüller)] that strongly depend on insecticide use for their control. Concentration and dose-mortality curves were recorded at 24 and 48 h postapplication. Large mortality differences between insecticides (maximum 7,800-fold for LD50) were followed by much lower, yet important, differences between species (maximum 115-fold), and sexes (maximum 41.5-fold). Significant interactions between the three factors indicate that they are not independent from each other. Interestingly, with the organophosphate chlorpyrifos, males of the three species were less susceptible than females, which was unexpected, as females are larger than males. Higher female sensitivity to organophosphates has been reported previously but only in G. molesta, not in other moth species. Our results highlight the importance of taking into account sex in dose-mortality studies with adult moths. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Acute toxicities of pharmaceuticals toward green algae. mode of action, biopharmaceutical drug disposition classification system and quantile regression models.

    Science.gov (United States)

    Villain, Jonathan; Minguez, Laetitia; Halm-Lemeille, Marie-Pierre; Durrieu, Gilles; Bureau, Ronan

    2016-02-01

    The acute toxicities of 36 pharmaceuticals towards green algae were estimated from a set of quantile regression models representing the first global quantitative structure-activity relationships. The selection of these pharmaceuticals was based on their predicted environmental concentrations. An agreement between the estimated values and the observed acute toxicity values was found for several families of pharmaceuticals, in particular, for antidepressants. A recent classification (BDDCS) of drugs based on ADME properties (Absorption, Distribution, Metabolism and Excretion) was clearly correlated with the acute ecotoxicities towards algae. Over-estimation of toxicity from our QSAR models was observed for classes 2, 3 and 4 whereas our model results were in agreement for the class 1 pharmaceuticals. Clarithromycin, a class 3 antibiotic characterized by weak metabolism and high solubility, was the most toxic to algae (molecular stability and presence in surface water). Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Intracellular Diagnostics: Hunting for the Mode of Action of Redox-Modulating Selenium Compounds in Selected Model Systems

    Directory of Open Access Journals (Sweden)

    Dominika Mániková

    2014-08-01

    Full Text Available Redox-modulating compounds derived from natural sources, such as redox active secondary metabolites, are currently of considerable interest in the field of chemoprevention, drug and phytoprotectant development. Unfortunately, the exact and occasionally even selective activity of such products, and the underlying (bio-chemical causes thereof, are often only poorly understood. A combination of the nematode- and yeast-based assays provides a powerful platform to investigate a possible biological activity of a new compound and also to explore the “redox link” which may exist between its activity on the one side and its chemistry on the other. Here, we will demonstrate the usefulness of this platform for screening several selenium and tellurium compounds for their activity and action. We will also show how the nematode-based assay can be used to obtain information on compound uptake and distribution inside a multicellular organism, whilst the yeast-based system can be employed to explore possible intracellular mechanisms via chemogenetic screening and intracellular diagnostics. Whilst none of these simple and easy-to-use assays can ultimately substitute for in-depth studies in human cells and animals, these methods nonetheless provide a first glimpse on the possible biological activities of new compounds and offer direction for more complicated future investigations. They may also uncover some rather unpleasant biochemical actions of certain compounds, such as the ability of the trace element supplement selenite to induce DNA strand breaks.

  1. Mode of Action Analyses of Neferine, a Bisbenzylisoquinoline Alkaloid of Lotus (Nelumbo nucifera against Multidrug-Resistant Tumor Cells

    Directory of Open Access Journals (Sweden)

    Onat Kadioglu

    2017-05-01

    Full Text Available Neferine, a bisbenzylisoquinoline alkaloid isolated from the green seed embryos of Lotus (Nelumbo nucifera Gaertn, has been previously shown to have various anti-cancer effects. In the present study, we evaluated the effect of neferine in terms of P-glycoprotein (P-gp inhibition via in vitro cytotoxicity assays, R123 uptake assays in drug-resistant cancer cells, in silico molecular docking analysis on human P-gp and in silico absorption, distribution, metabolism, and excretion (ADME, quantitative structure activity relationships (QSAR and toxicity analyses. Lipinski rule of five were mainly considered for the ADME evaluation and the preset descriptors including number of hydrogen bond donor, acceptor, hERG IC50, logp, logD were considered for the QSAR analyses. Neferine revealed higher toxicity toward paclitaxel- and doxorubicin-resistant breast, lung or colon cancer cells, implying collateral sensitivity of these cells toward neferine. Increased R123 uptake was observed in a comparable manner to the control P-gp inhibitor, verapamil. Molecular docking analyses revealed that neferine still interacts with P-gp, even if R123 was pre-bound. Bioinformatical ADME and toxicity analyses revealed that neferine possesses the druggability parameters with no predicted toxicity. In conclusion, neferine may allocate the P-gp drug-binding pocket and prevent R123 binding in agreement with P-gp inhibition experiments, where neferine increased R123 uptake.

  2. Investigation into the intracellular fates, speciation and mode of action of selenium-containing neuroprotective agents using XAS and XFM.

    Science.gov (United States)

    Wedding, Jason L; Lai, Barry; Vogt, Stefan; Harris, Hugh H

    2018-04-06

    A variety of selenium compounds have been observed to provide protection against oxidative stress, presumably by mimicking the mechanism of action of the glutathione peroxidases. However, the selenium chemistry that underpins the action of these compounds has not been unequivocally established. The synchrotron based techniques, X-ray absorption spectroscopy and X-ray fluorescence microscopy were used to examine the cellular speciation and distribution of selenium in SH-SY5Y cells pretreated with one of two diphenyl diselenides, or ebselen, followed by peroxide insult. Bis(2-aminophenyl)diselenide was shown to protect against oxidative stress conditions which mimic ischemic strokes, while its nitro analogue, bis(2-nitrophenyl)diselenide did not. This protective activity was tentatively assigned to the reductive cleavage of bis(2-aminophenyl)diselenide inside human neurocarcinoma cells, SH-SY5Y, while bis(2-nitrophenyl)diselenide remained largely unchanged. The distinct chemistries of the related compounds were traced by the changes in selenium speciation in bulk pellets of treated SH-SY5Y cells detected by X-ray absorption spectroscopy. Further, bis(2-aminophenyl)diselenide, like the known stroke mitigation agent ebselen, was observed by X-ray fluorescence imaging to penetrate into the nucleus of SH-SY5Y cells while bis(2-nitrophenyl)diselenide was observed to be excluded from the nuclear region. The differences in activity were thus attributed to the varied speciation and cellular localisation of the compounds, or their metabolites, as detected by X-ray absorption spectroscopy and X-ray fluorescence microscopy. The work is significant as it links, for the first time, the protective action of selenium compounds against redox stress with particular chemical speciation using a direct measurement approach. Copyright © 2018. Published by Elsevier B.V.

  3. Pharmacokinetics and pharmacodynamics of orally administered acetylenic tricyclic bis(cyanoenone), a highly potent Nrf2 activator with a reversible covalent mode of action

    Energy Technology Data Exchange (ETDEWEB)

    Kostov, Rumen V.; Knatko, Elena V.; McLaughlin, Lesley A.; Henderson, Colin J. [Jacqui Wood Cancer Centre, Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee, DD1 9SY, Scotland (United Kingdom); Zheng, Suqing [Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY, 11794 (United States); Huang, Jeffrey T.-J. [Jacqui Wood Cancer Centre, Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee, DD1 9SY, Scotland (United Kingdom); Honda, Tadashi [Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY, 11794 (United States); Dinkova-Kostova, Albena T., E-mail: a.dinkovakostova@dundee.ac.uk [Jacqui Wood Cancer Centre, Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee, DD1 9SY, Scotland (United Kingdom); Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205 (United States); Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205 (United States)

    2015-09-25

    The acetylenic tricyclic bis(cyanoenone) TBE-31 is a highly potent cysteine targeting compound with a reversible covalent mode of action; its best-characterized target being Kelch-like ECH-associated protein-1 (Keap1), the cellular sensor for oxidants and electrophiles. TBE-31 reacts with cysteines of Keap1, impairing its ability to target nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) for degradation. Consequently, Nrf2 accumulates and orchestrates cytoprotective gene expression. In this study we investigated the pharmacokinetic and pharmacodynamic properties of TBE-31 in C57BL/6 mice. After a single oral dose of 10 μmol/kg (∼200 nmol/animal), the concentration of TBE-31 in blood exhibited two peaks, at 22.3 nM and at 15.5 nM, 40 min and 4 h after dosing, respectively, as determined by a quantitative stable isotope dilution LC-MS/MS method. The AUC{sub 0–24h} was 195.5 h/nmol/l, the terminal elimination half-life was 10.2 h, and the k{sub el} was 0.068 h{sup −1}. To assess the pharmacodynamics of Nrf2 activation by TBE-31, we determined the enzyme activity of its prototypic target, NAD(P)H:quinone oxidoreductase 1 (NQO1) and found it elevated by 2.4- and 1.5-fold in liver and heart, respectively. Continuous feeding for 18 days with diet delivering the same daily doses of TBE-31 under conditions of concurrent treatment with the immunosuppressive agent azathioprine had a similar effect on Nrf2 activation without any indications of toxicity. Together with previous reports showing the cytoprotective effects of TBE-31 in animal models of carcinogenesis, our results demonstrate the high potency, efficacy and suitability for chronic administration of cysteine targeting reversible covalent drugs. - Highlights: • TBE-31 is a cysteine targeting compound with a reversible covalent mode of action. • After a single oral dose, the blood concentration of TBE-31 exhibits two peaks. • Oral TBE-31 is a potent activator of Nrf2-dependent enzymes in

  4. A Novel Methodology for Bioenergetic Analysis of Plasmodium falciparum Reveals a Glucose-Regulated Metabolic Shift and Enables Mode of Action Analyses of Mitochondrial Inhibitors.

    Science.gov (United States)

    Sakata-Kato, Tomoyo; Wirth, Dyann F

    2016-12-09

    Given that resistance to all drugs in clinical use has arisen, discovery of new antimalarial drug targets is eagerly anticipated. The Plasmodium mitochondrion has been considered a promising drug target largely based on its significant divergence from the host organelle as well as its involvement in ATP production and pyrimidine biosynthesis. However, the functions of Plasmodium mitochondrial protein complexes and associated metabolic pathways are not fully characterized. Here, we report the development of novel and robust bioenergetic assay protocols for Plasmodium falciparum asexual parasites utilizing a Seahorse Bioscience XFe24 Extracellular Flux Analyzer. These protocols allowed us to simultaneously assess the direct effects of metabolites and inhibitors on mitochondrial respiration and glycolytic activity in real-time with the readout of oxygen consumption rate and extracellular acidification rate. Using saponin-freed parasites at the schizont stage, we found that succinate, malate, glycerol-3-phosphate, and glutamate, but not pyruvate, were able to increase the oxygen consumption rate and that glycerol-3-phosphate dehydrogenase had the largest potential as an electron donor among tested mitochondrial dehydrogenases. Furthermore, we revealed the presence of a glucose-regulated metabolic shift between oxidative phosphorylation and glycolysis. We measured proton leak and reserve capacity and found bioenergetic evidence for oxidative phosphorylation in erythrocytic stage parasites but at a level much lower than that observed in mammalian cells. Lastly, we developed an assay platform for target identification and mode of action studies of mitochondria-targeting antimalarials. This study provides new insights into the bioenergetics and metabolomics of the Plasmodium mitochondria.

  5. Mode of action human relevance (species concordance) framework: Evolution of the Bradford Hill considerations and comparative analysis of weight of evidence.

    Science.gov (United States)

    Meek, M E Bette; Palermo, Christine M; Bachman, Ammie N; North, Colin M; Jeffrey Lewis, R

    2014-06-01

    The mode of action human relevance (MOA/HR) framework increases transparency in systematically considering data on MOA for end (adverse) effects and their relevance to humans. This framework continues to evolve as experience increases in its application. Though the MOA/HR framework is not designed to address the question of "how much information is enough" to support a hypothesized MOA in animals or its relevance to humans, its organizing construct has potential value in considering relative weight of evidence (WOE) among different cases and hypothesized MOA(s). This context is explored based on MOA analyses in published assessments to illustrate the relative extent of supporting data and their implications for dose-response analysis and involved comparisons for chemical assessments on trichloropropane, and carbon tetrachloride with several hypothesized MOA(s) for cancer. The WOE for each hypothesized MOA was summarized in narrative tables based on comparison and contrast of the extent and nature of the supporting database versus potentially inconsistent or missing information. The comparison was based on evolved Bradford Hill considerations rank ordered to reflect their relative contribution to WOE determinations of MOA taking into account increasing experience in their application internationally. This clarification of considerations for WOE determinations as a basis for comparative analysis is anticipated to contribute to increasing consistency in the application of MOA/HR analysis and potentially, transparency in separating science judgment from public policy considerations in regulatory risk assessment. Copyright © 2014. The Authors. Journal of Applied Toxicology Published by John Wiley & Sons Ltd.

  6. Application of benchmark dose modeling to protein expression data in the development and analysis of mode of action/adverse outcome pathways for testicular toxicity.

    Science.gov (United States)

    Chepelev, Nikolai L; Meek, M E Bette; Yauk, Carole Lyn

    2014-11-01

    Reliable quantification of gene and protein expression has potential to contribute significantly to the characterization of hypothesized modes of action (MOA) or adverse outcome pathways for critical effects of toxicants. Quantitative analysis of gene expression by benchmark dose (BMD) modeling has been facilitated by the development of effective software tools. In contrast, protein expression is still generally quantified by a less robust effect level (no or lowest [adverse] effect levels) approach, which minimizes its potential utility in the consideration of dose-response and temporal concordance for key events in hypothesized MOAs. BMD modeling is applied here to toxicological data on testicular toxicity to investigate its potential utility in analyzing protein expression relevant to the proposed MOA to inform human health risk assessment. The results illustrate how the BMD analysis of protein expression in animal tissues in response to toxicant exposure: (1) complements other toxicity data, and (2) contributes to consideration of the empirical concordance of dose-response relationships, as part of the weight of evidence for hypothesized MOAs to facilitate consideration and application in regulatory risk assessment. Lack of BMD analysis in proteomics has likely limited its use for these purposes. This paper illustrates the added value of BMD modeling to support and strengthen hypothetical MOAs as a basis to facilitate the translation and uptake of the results of proteomic research into risk assessment. Copyright © 2014 Her Majesty the Queen in Right of Canada. Journal of Applied Toxicology © 2014 John Wiley & Sons, Ltd.

  7. Mode of action and in vitro susceptibility of mastitis pathogens to macedocin ST91KM and preparation of a teat seal containing the bacteriocin

    Directory of Open Access Journals (Sweden)

    Renee Pieterse

    2010-03-01

    Full Text Available Mastitis is considered to be the most economically costly disease affecting the dairy industry. Regular dosage of animals with antibiotics, including use of prophylactic concentrations, may select for resistant strains. The purpose of this study was to determine the mode of action of a new bacteriocin (macedocin ST91KM, to evaluate the antimicrobial resistance of mastitis pathogens to antibiotics commonly used in treatment remedies, and to introduce the possible use of an alternative antimicrobial agent. The bacteriocin macedocin ST91KM, produced by Streptococcus gallolyticus subsp. macedonicus ST91KM, is bactericidal to Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis and Staphylococcus aureus associated with mastitis infections, including strains resistant to methicillin and oxacillin. Sensitive cells were deformed and secreted nucleotides, K+ and β-galactosidase when exposed to macedocin ST91KM. Adsorption of the peptide to target cells decreased in the presence of solvents, suggesting that receptors on the cell surfaces have lipid moieties. No adsorption was recorded in the presence of MgCl2, KI and Na2CO3, suggesting that ionic strength plays an important role. A teat seal preparation containing macedocin ST91KM effectively released the peptide and inhibited the growth of S. agalactiae. Macedocin ST91KM could form the basis for alternative dry cow therapy to prevent mastitis infections in dairy cows as it is effective against pathogens that display resistance to conventional antibiotic therapy.

  8. Comparing the potency of chemicals with multiple modes of action in aquatic toxicology: Acute toxicity due to narcosis versus reactive toxicity of acrylic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Freidig, A.P.; Verhaar, H.J.M.; Hermens, J.L.M. [Utrecht Univ. (Netherlands). Research Inst. of Toxicology

    1999-09-01

    A series of acrylates and methacrylates was used to illustrate a strategy to compare the importance of two modes of action (MOA) and thereby identify the predominant cause of acute fish toxicity. Acrylic compounds are known to be Michael acceptors and may therefore react with glutathione (GSH), causing GSH-depletion in vivo (reactive mechanism). On the other hand, acrylates may also act by a nonspecific mechanism (narcosis). The following two, physiologically meaningful parameters were calculated in order to estimate the contribution of these two mechanisms to the overall acute toxicity: (i) a lipid normalized body burden for narcosis and (ii) the potential degree of GSH depletion by chemical reactivity. The degree of GSH depletion was found to be related to the product of the reactivity toward GSH and the exposure concentration. This model was validated with four model compounds and an in vivo study. For both MOA, toxic ratios were calculated and compared for all chemicals in the series. The approach enables the comparison of the contribution to toxicity of chemicals with more than on MOA.

  9. Assessment of the mode of action underlying development of rodent small intestinal tumors following oral exposure to hexavalent chromium and relevance to humans

    Science.gov (United States)

    Proctor, Deborah M.; Suh, Mina; Haws, Laurie C.; Kirman, Christopher R.; Harris, Mark A.

    2013-01-01

    Chronic exposure to high concentrations of hexavalent chromium (Cr(VI)) in drinking water causes intestinal adenomas and carcinomas in mice, but not in rats. Cr(VI) causes damage to intestinal villi and crypt hyperplasia in mice after only one week of exposure. After two years of exposure, intestinal damage and crypt hyperplasia are evident in mice (but not rats), as are intestinal tumors. Although Cr(VI) has genotoxic properties, these findings suggest that intestinal tumors in mice arise as a result of chronic mucosal injury. To better understand the mode of action (MOA) of Cr(VI) in the intestine, a 90-day drinking water study was conducted to collect histological, biochemical, toxicogenomic and pharmacokinetic data in intestinal tissues. Using MOA analyses and human relevance frameworks proposed by national and international regulatory agencies, the weight of evidence supports a cytotoxic MOA with the following key events: (a) absorption of Cr(VI) from the intestinal lumen, (b) toxicity to intestinal villi, (c) crypt regenerative hyperplasia and (d) clonal expansion of mutations within the crypt stem cells, resulting in late onset tumorigenesis. This article summarizes the data supporting each key event in the MOA, as well as data that argue against a mutagenic MOA for Cr(VI)-induced intestinal tumors. PMID:23445218

  10. Synergistic activity and mode of action of flavonoids isolated from smaller galangal and amoxicillin combinations against amoxicillin-resistant Escherichia coli.

    Science.gov (United States)

    Eumkeb, G; Siriwong, S; Phitaktim, S; Rojtinnakorn, N; Sakdarat, S

    2012-01-01

    The smaller galangal is extracted, purified and identified the bioactive compounds. The purpose of this research was to investigate whether these isolated compounds have antibacterial and synergistic activity against amoxicillin-resistant Escherichia coli (AREC) when used singly and in combination with amoxicillin. The primarily mode of action is also studied. The galangin, kaempferide and kaempferide-3-O-β-d-glucoside were isolated. The minimum inhibitory concentrations(MIC) of amoxicillin and these flavonoids against AREC were between 500 and >1000 μg ml(-1). Synergistic activity was observed on combining amoxicillin with these flavonoids. The combinations of amoxicillin and these flavonoids exhibited a synergistic effect, reducing AREC cell numbers. Electron microscopy showed that these combinations damaged the ultrastructure of AREC cells. The results indicated that these combinations altered outer membrane permeability but not affecting cytoplasmic membrane. Enzyme assays showed that these flavonoids had an inhibitory activity against penicillinase. These results indicated that these flavonoids have the potential to reverse bacterial resistance to amoxicillin in AREC and may operate via three mechanisms: inhibition of peptidoglycan and ribosome synthesis, alteration of outer membrane permeability, and interaction with β-lactamases. These findings offer the potential to develop a new generation of phytopharmaceuticals to treat AREC. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  11. Effect of mitochondrially targeted carboxy proxyl nitroxide on Akt-mediated survival in Daudi cells: Significance of a dual mode of action.

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    Gokul Variar

    Full Text Available Vicious cycles of mutations and reactive oxygen species (ROS generation contribute to cancer progression. The use of antioxidants to inhibit ROS generation promotes cytostasis by affecting the mutation cycle and ROS-dependent survival signaling. However, cancer cells select mutations to elevate ROS albeit maintaining mitochondrial hyperpolarization (Δψm, even under hypoxia. From this perspective, the use of drugs that disrupt both ROS generation and Δψm is a viable anticancer strategy. Hence, we studied the effects of mitochondrially targeted carboxy proxyl nitroxide (Mito-CP and a control ten carbon TPP moiety (Dec-TPP+ in the human Burkitt lymphoma cell line (Daudi and normal peripheral blood mononuclear cells under hypoxia and normoxia. We found preferential localization, Δψm and adenosine triphosphate loss, and significant cytotoxicity by Mito-CP in Daudi cells alone. Interestingly, ROS levels were decreased and maintained in hypoxic and normoxic cancer cells, respectively, by Mito-CP but not Dec-TPP+, therefore preventing any adaptive signaling. Moreover, dual effects on mitochondrial bioenergetics and ROS by Mito-CP curtailed the cancer survival via Akt inhibition, AMPK-HIF-1α activation and promoted apoptosis via increased BCL2-associated X protein and poly (ADP-ribose polymerase expression. This dual mode of action by Mito-CP provides a better explanation of the application of antioxidants with specific relevance to cancerous transformation and adaptations in the Daudi cell line.

  12. Sources and modes of action of invasive knotweed allelopathy: the effects of leaf litter and trained soil on the germination and growth of native plants

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    Madalin Parepa

    2012-05-01

    Full Text Available Invasive knotweeds, native to Eastern Asia, are among the most dominant plant invaders of European and North American temperate ecosystems. Recent studies indicate that one cause of this dominance might be allelopathy, but the possible sources and modes of action of this allelopathy are insufficiently understood. Here, we asked whether the invasive knotweed Fallopia × bohemica can exert allelopathic effects on native plants also through its leaf litter, or through persistent soil contaminants, and whether these affect the germination or growth of native plants. In a germination experiment with nine native species neither litter leachate, an aqueous extract of knotweed leaves added to the soil, nor trained soil with a history of Fallopia pre-cultivation suppressed the germination or early growth of natives. A mesocosm study with experimental native communities showed that the presence of F. × bohemica, although not a dominant in these communities, caused significant shifts of life-history strategy in two dominant natives, and that similar effects could be elicited through litter leachates or trained soil alone. However, there were hardly any effects on the biomass of natives. Our study indicates that knotweed allelopathy acts on the growth rather than germination of natives, and that soil contamination through persistent allelochemicals may not be a significant problem in habitat restoration. It also shows that allelopathic effects can sometimes be subtle changes in life-history and allocation patterns of the affected species.

  13. Mode of Action Temu Kunci (Kaempferia pandurata Essential Oil on E. coli K1.1 Cell Determined by Leakage of Material Cell and Salt Tolerance Assays

    Directory of Open Access Journals (Sweden)

    MIKSUSANTI

    2008-06-01

    Full Text Available The essential oil of Kaempferia pandurata consist of terpen and oxygenated terpen that exhibits broad-spectrum antimicrobial activity. It's mode of action against the gram-negative bacterium E. coli K1.1 has been investigated using a range of treatments. The mode action of the essential oil were analyzed by it's ability to leakage E. coli K1.1 cell, to change permeability of the cell, and to alter salt tolerance of the cell. Ion leakage from the cell were analyzed by atomic absorption spectrophotometer. Salt tolerance assays was conducted by investigating the ability of E. coli K1.1 treated with temu kunci essential oil to grow on NA supplemented with NaCl. Protein and acid nucleic leakage were analyzed by UV spectrophotometer. There were inorganic compound leakage (potassium, calcium ion and organic compound leakage (nucleic acid, protein from cytoplasmic membrane, after exposing this organism to essential oil of Kaempferia pandurata. The more concentration of oil added, the more leakage was observed due to the loss of absorbing material such as nucleic acid (260 nm and protein (280 nm, the loss of potassium and calcium ion, and loss of the salt tolerance of E. coli K1.1.

  14. Evaluation of Antifungal Activity and Mode of Action of New Coumarin Derivative, 7-Hydroxy-6-nitro-2H-1-benzopyran-2-one, against Aspergillus spp.

    Science.gov (United States)

    Guerra, Felipe Queiroga Sarmento; de Araújo, Rodrigo Santos Aquino; de Sousa, Janiere Pereira; Pereira, Fillipe de Oliveira; Mendonça-Junior, Francisco J. B.; Barbosa-Filho, José M.; de Oliveira Lima, Edeltrudes

    2015-01-01

    Aspergillus spp. produce a wide variety of diseases. For the treatment of such infections, the azoles and Amphotericin B are used in various formulations. The treatment of fungal diseases is often ineffective, because of increases in azole resistance and their several associated adverse effects. To overcome these problems, natural products and their derivatives are interesting alternatives. The aim of this study was to examine the effects of coumarin derivative, 7-hydroxy-6-nitro-2H-1-benzopyran-2-one (Cou-NO2), both alone and with antifungal drugs. Its mode of action against Aspergillus spp. Cou-NO2 was tested to evaluate its effects on mycelia growth and germination of fungal conidia of Aspergillus spp. We also investigated possible Cou-NO2 action on cell walls (0.8 M sorbitol) and on Cou-NO2 to ergosterol binding in the cell membrane. The study shows that Cou-NO2 is capable of inhibiting both the mycelia growth and germination of conidia for the species tested, and that its action affects the structure of the fungal cell wall. At subinhibitory concentration, Cou-NO2 enhanced the in vitro effects of azoles. Moreover, in combination with azoles (voriconazole and itraconazole) Cou-NO2 displays an additive effect. Thus, our study supports the use of coumarin derivative 7-hydroxy-6-nitro-2H-1-benzopyran-2-one as an antifungal agent against Aspergillus species. PMID:26175794

  15. Tissue Distribution of Polychlorinated Biphenyls and Organochlorine Pesticides and Potential Toxicity to Alaskan Northern Fur Seals Assessed Using PCBs Congener Specific Mode of Action Schemes

    Science.gov (United States)

    The concentrations of 145 polychlorinated biphenyl (PCB) congeners were measured using gas chromatography-ion trap mass spectrometry in 8 different tissues (blubber, brain, heart, kidney, liver, lung, muscle, and reproductive tissues) of 10 Alaskan northern fur seals. The mean concentrations of bot...

  16. Toxicity assessment of four insecticides with different modes of action on pupae and adults of Eriopis connexa (Coleoptera: Coccinellidae), a relevant predator of the Neotropical Region.

    Science.gov (United States)

    Fogel, Marilina Noelia; Schneider, Marcela Inés; Rimoldi, Federico; Ladux, Lorena Sabrina; Desneux, Nicolas; Ronco, Alicia Estela

    2016-08-01

    Pesticides can be toxic to nontarget organisms including the natural enemies of agricultural pests, thus reducing the biodiversity of agroecosystems. The lethal and sublethal effects of four insecticides with different modes of action-pyriproxyfen, teflubenzuron, acetamiprid, and cypermethrin-were evaluated on pupae and adults of Eriopis connexa, an effective predator in horticultural crops. Pupal survival was reduced by pyriproxyfen (26 %) and cypermethrin (41 %). Malformations in adults emerged from treated pupae were observed after acetamiprid (82.7 and 100 % for 100 and 200 mg a.i./l, respectively), pyriproxyfen (48.6 %), and cypermethrin (13.3 %) treatments. A longer mean oviposition time was also observed in adults emerged from pupae treated with cypermethrin. Moreover, the latter insecticide as well as teflubenzuron did not reduce reproductive parameters, whereas females emerged from pyriproxyfen-treated pupae were not be able to lay eggs even when females showed large abdomens. Upon exposure of adults, survival was reduced to approximately 90 % by acetamiprid, but no reduction occurred with pyriproxyfen, teflubenzuron, or cypermethrin though the fecundity at fifth oviposition time of the female survivors was reduced. Pyriproxyfen decreased the hatching at all the oviposition times tested, whereas fertility was reduced in the fourth and fifth ovipositions by teflubenzuron and in the first and third ovipositions by cypermethrin. In conclusion, all four insecticides tested exhibited lethal or sublethal effects, or both, on E. connexa. The neurotoxic insecticides were more harmful than the insect-growth regulators, and pupae were more susceptible than adults. The toxicity of insecticides on the conservation of predators in agroecosystems of the Neotropical Region is discussed.

  17. The anti-adhesive mode of action of a purified mushroom (Lentinus edodes) extract with anticaries and antigingivitis properties in two oral bacterial phatogens.

    Science.gov (United States)

    Signoretto, Caterina; Marchi, Anna; Bertoncelli, Anna; Burlacchini, Gloria; Papetti, Adele; Pruzzo, Carla; Zaura, Egija; Lingström, Peter; Ofek, Itzhak; Pratten, Jonathan; Spratt, David A; Wilson, Michael; Canepari, Pietro

    2014-02-24

    In previous works we have shown that a low-molecular-mass (LMM) fraction from mushroom (Lentinus edodes) homogenate interferes with binding of Streptococcus mutans to hydroxyapatite and Prevotella intermedia to gingival cells. Additionally, inhibition of biofilm formation of both odonto- and periodonto-pathogenic bacteria and detachment from preformed biofilms have been described for this compound. Further purification of mushroom extract has been recently achieved and a sub-fraction (i.e. # 5) has been identified as containing the majority of the mentioned biological activities. The aim of this study was to characterise the bacterial receptors for the purified mushroom sub-fraction #5 in order to better elucidate the mode of action of this compound when interfering with bacterial adhesion to host surfaces or with bacteria-bacteria interactions in the biofilm state. Candidate bacterial molecules to act as target of this compound were bacterial surface molecules involved in cell adhesion and biofilm formation, and, thus, we have considered cell wall associated proteins (CWPs), teichoic acid (TA) and lipoteichoic acid (LTA) of S. mutans, and outer membrane proteins (OMPs) and lipopolysaccharide (LPS) of P. intermedia. Fifteen S. mutans CWPs and TA were capable of binding sub-fraction #5, while LTA did not. As far as P. intermedia is concerned, we show that five OMPs interact with sub-fraction # 5. Capacity of binding to P. intermedia LPS was also studied but in this case negative results were obtained. Binding sub-fraction # 5 to surface molecules of S. mutans or P. intermedia may result in inactivation of their physiological functions. As a whole, these results indicate, at molecular level, the bacterial surface alterations affecting adhesion and biofim formation. For these antimicrobial properties, the compound may find use in daily oral hygiene.

  18. A comparative study on the modes of action of TAK-438, a novel potassium-competitive acid blocker, and lansoprazole in primary cultured rabbit gastric glands.

    Science.gov (United States)

    Matsukawa, Jun; Hori, Yasunobu; Nishida, Haruyuki; Kajino, Masahiro; Inatomi, Nobuhiro

    2011-05-01

    TAK-438 is a novel potassium-competitive acid blocker (P-CAB) type antisecretory agent that reversibly inhibits gastric H+, K+-ATPase. Previously, we showed that TAK-438 has superior efficacy compared to lansoprazole, a proton pump inhibitor, in the inhibition of acid secretion in vivo. In this study, we investigated the differences in the mode of actions of the two drugs using primary cultured rabbit gastric glands. TAK-438 and lansoprazole inhibited gastric acid formation in acutely isolated gastric glands (IC₅₀) values, 0.30 and 0.76 μM, respectively). In cultured gastric glands that were preincubated with TAK-438, the inhibitory effect on forskolin-stimulated acid formation was augmented over the incubation period, whereas the inhibitory effect of lansoprazole was not affected by time of incubation. Next, we evaluated the durations of the actions of TAK-438 and lansoprazole after gastric glands were incubated with either drug for 2h followed by washout. Even 8h after the drug washout, TAK-438 at higher concentrations inhibited acid formation, but the inhibitory effect of lansoprazole disappeared immediately after washout. Additionally, only a small amount of [¹⁴C] lansoprazole accumulated in resting glands, and this accumulation was enhanced by treatment with 1 μM of forskolin. In contrast, high levels of [¹⁴C] TAK-438 accumulated in both resting and forskolin-treated glands. Furthermore, a 2-h preincubation followed by washout demonstrated a slow clearance of [¹⁴C] TAK-438 from the glands. These findings suggest that TAK-438 exerts a longer and more potent antisecretory effect than lansoprazole as a result of its high accumulation and slow clearance from the gastric glands. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. New insights into the structure and mode of action of Mo-CBP3, an antifungal chitin-binding protein of Moringa oleifera seeds.

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    Adelina B Batista

    Full Text Available Mo-CBP3 is a chitin-binding protein purified from Moringa oleifera Lam. seeds that displays inhibitory activity against phytopathogenic fungi. This study investigated the structural properties and the antifungal mode of action of this protein. To this end, circular dichroism spectroscopy, antifungal assays, measurements of the production of reactive oxygen species and microscopic analyses were utilized. Mo-CBP3 is composed of 30.3% α-helices, 16.3% β-sheets, 22.3% turns and 30.4% unordered forms. The Mo-CBP3 structure is highly stable and retains its antifungal activity regardless of temperature and pH. Fusarium solani was used as a model organism for studying the mechanisms by which this protein acts as an antifungal agent. Mo-CBP3 significantly inhibited spore germination and mycelial growth at 0.05 mg.mL-1. Mo-CBP3 has both fungistatic and fungicidal effects, depending on the concentration used. Binding of Mo-CBP3 to the fungal cell surface is achieved, at least in part, via electrostatic interactions, as salt was able to reduce its inhibitory effect. Mo-CBP3 induced the production of ROS and caused disorganization of both the cytoplasm and the plasma membrane in F. solani cells. Based on its high stability and specific toxicity, with broad-spectrum efficacy against important phytopathogenic fungi at low inhibitory concentrations but not to human cells, Mo-CBP3 has great potential for the development of new antifungal drugs or transgenic crops with enhanced resistance to phytopathogens.

  20. BRCA-Monet: a breast cancer specific drug treatment mode-of-action network for treatment effective prediction using large scale microarray database

    Science.gov (United States)

    2013-01-01

    Background Connectivity map (cMap) is a recent developed dataset and algorithm for uncovering and understanding the treatment effect of small molecules on different cancer cell lines. It is widely used but there are still remaining challenges for accurate predictions. Method Here, we propose BRCA-MoNet, a network of drug mode of action (MoA) specific to breast cancer, which is constructed based on the cMap dataset. A drug signature selection algorithm fitting the characteristic of cMap data, a quality control scheme as well as a novel query algorithm based on BRCA-MoNet are developed for more effective prediction of drug effects. Result BRCA-MoNet was applied to three independent data sets obtained from the GEO database: Estrodial treated MCF7 cell line, BMS-754807 treated MCF7 cell line, and a breast cancer patient microarray dataset. In the first case, BRCA-MoNet could identify drug MoAs likely to share same and reverse treatment effect. In the second case, the result demonstrated the potential of BRCA-MoNet to reposition drugs and predict treatment effects for drugs not in cMap data. In the third case, a possible procedure of personalized drug selection is showcased. Conclusions The results clearly demonstrated that the proposed BRCA-MoNet approach can provide increased prediction power to cMap and thus will be useful for identification of new therapeutic candidates. Website: The web based application is developed and can be access through the following link http://compgenomics.utsa.edu/BRCAMoNet/ PMID:24564956

  1. Investigation of the Mode of Action Underlying the Tumorigenic Response Induced in B6C3F1 Mice Exposed Orally to Hexavalent Chromium

    Science.gov (United States)

    Thompson, Chad M.; Proctor, Deborah M.; Haws, Laurie C.; Hébert, Charles D.; Grimes, Sheila D.; Shertzer, Howard G.; Kopec, Anna K.; Hixon, J.Gregory; Zacharewski, Timothy R.; Harris, Mark A.

    2011-01-01

    Chronic ingestion of high concentrations of hexavalent chromium [Cr(VI)] in drinking water induces intestinal tumors in mice. To investigate the mode of action (MOA) underlying these tumors, a 90-day drinking water study was conducted using similar exposure conditions as in a previous cancer bioassay, as well as lower (heretofore unexamined) drinking water concentrations. Tissue samples were collected in mice exposed for 7 or 90 days and subjected to histopathological, biochemical, toxicogenomic, and toxicokinetic analyses. Described herein are the results of toxicokinetic, biochemical, and pathological findings. Following 90 days of exposure to 0.3–520 mg/l of sodium dichromate dihydrate (SDD), total chromium concentrations in the duodenum were significantly elevated at ≥ 14 mg/l. At these concentrations, significant decreases in the reduced-to-oxidized glutathione ratio (GSH/GSSG) were observed. Beginning at 60 mg/l, intestinal lesions were observed including villous cytoplasmic vacuolization. Atrophy, apoptosis, and crypt hyperplasia were evident at ≥ 170 mg/l. Protein carbonyls were elevated at concentrations ≥ 4 mg/l SDD, whereas oxidative DNA damage, as assessed by 8-hydroxydeoxyguanosine, was not increased in any treatment group. Significant decreases in the GSH/GSSG ratio and similar histopathological lesions as observed in the duodenum were also observed in the jejunum following 90 days of exposure. Cytokine levels (e.g., interleukin-1β) were generally depressed or unaltered at the termination of the study. Overall, the data suggest that Cr(VI) in drinking water can induce oxidative stress, villous cytotoxicity, and crypt hyperplasia in the mouse intestine and may underlie the MOA of intestinal carcinogenesis in mice. PMID:21712504

  2. Control of postharvest soft rot caused by Erwinia carotovora of vegetables by a strain of Bacillus amyloliquefaciens and its potential modes of action.

    Science.gov (United States)

    Zhao, Yancun; Li, Pengxia; Huang, Kaihong; Wang, Yuning; Hu, Huali; Sun, Ya

    2013-03-01

    Erwinia carotovora subsp. carotovora (Ecc), the causal agent of bacterial soft rot, is one of the destructive pathogens of postharvest vegetables. In this study, a bacterial isolate (BGP20) from the vegetable farm soil showed strong antagonistic activity against Ecc in vitro, and its twofold cell-free culture filtrate showed excellent biocontrol effect in controlling the postharvest bacterial soft rot of potatoes at 25 °C. The anti-Ecc metabolites produced by the isolate BGP20 had a high resistance to high temperature, UV-light and protease K. Based on the colonial morphology, cellular morphology, sporulation, and partial nucleotide sequences of 16S rRNA and gyrB gene, the isolate BGP20 was identified as Bacillus amyloliquefaciens subsp. plantarum. Further in vivo assays showed that the BGP20 cell culture was more effective in controlling the postharvest bacterial soft rot of green peppers and Chinese cabbages than its twofold cell-free culture filtrate. In contrast, the biocontrol effect and safety of the BGP20 cell culture were very poor on potatoes. In the wounds of potatoes treated with both the antagonist BGP20 and the pathogen Ecc, the viable count of Ecc was 31,746 times that of BGP20 at 48 h of incubation at 25 °C. But in the wounds of green peppers, the viable count of BGP20 increased 182.3 times within 48 h, and that of Ecc increased only 51.3 %. In addition, the treatment with both BGP20 and Ecc induced higher activity of phenylalanine ammonia-lyase (PAL) than others in potatoes. But the same treatment did not induce an increase of PAL activity in green peppers. In conclusion, the present study demonstrated that the isolate BGP20 is a promising candidate in biological control of postharvest bacterial soft rot of vegetables, but its main mode of action is different among various vegetables.

  3. Modeling shows that the NS5A inhibitor daclatasvir has two modes of action and yields a shorter estimate of the hepatitis C virus half-life.

    Science.gov (United States)

    Guedj, Jeremie; Dahari, Harel; Rong, Libin; Sansone, Natasha D; Nettles, Richard E; Cotler, Scott J; Layden, Thomas J; Uprichard, Susan L; Perelson, Alan S

    2013-03-05

    The nonstructural 5A (NS5A) protein is a target for drug development against hepatitis C virus (HCV). Interestingly, the NS5A inhibitor daclatasvir (BMS-790052) caused a decrease in serum HCV RNA levels by about two orders of magnitude within 6 h of administration. However, NS5A has no known enzymatic functions, making it difficult to understand daclatasvir's mode of action (MOA) and to estimate its antiviral effectiveness. Modeling viral kinetics during therapy has provided important insights into the MOA and effectiveness of a variety of anti-HCV agents. Here, we show that understanding the effects of daclatasvir in vivo requires a multiscale model that incorporates drug effects on the HCV intracellular lifecycle, and we validated this approach with in vitro HCV infection experiments. The model predicts that daclatasvir efficiently blocks two distinct stages of the viral lifecycle, namely viral RNA synthesis and virion assembly/secretion with mean effectiveness of 99% and 99.8%, respectively, and yields a more precise estimate of the serum HCV half-life, 45 min, i.e., around four times shorter than previous estimates. Intracellular HCV RNA in HCV-infected cells treated with daclatasvir and the HCV polymerase inhibitor NM107 showed a similar pattern of decline. However, daclatasvir treatment led to an immediate and rapid decline of extracellular HCV titers compared to a delayed (6-9 h) and slower decline with NM107, confirming an effect of daclatasvir on both viral replication and assembly/secretion. The multiscale modeling approach, validated with in vitro kinetic experiments, brings a unique conceptual framework for understanding the mechanism of action of a variety of agents in development for the treatment of HCV.

  4. Toxicity ranking and toxic mode of action evaluation of commonly used agricultural adjuvants on the basis of bacterial gene expression profiles.

    Directory of Open Access Journals (Sweden)

    Ingrid Nobels

    used agricultural adjuvants based on toxicity and toxic mode of action data.

  5. A Reexamination of the PPAR-α Activation Mode of Action as a Basis for Assessing Human Cancer Risks of Environmental Contaminants

    Science.gov (United States)

    Guyton, Kathryn Z.; Chiu, Weihsueh A.; Bateson, Thomas F.; Jinot, Jennifer; Scott, Cheryl Siegel; Brown, Rebecca C.; Caldwell, Jane C.

    2009-01-01

    Background Diverse environmental contaminants, including the plasticizer di(2-ethylhexyl)phthalate (DEHP), are hepatocarcinogenic peroxisome proliferators in rodents. Peroxisome proliferator–activated receptor-α (PPAR-α) activation and its sequelae have been proposed to constitute a mode of action (MOA) for hepatocarcinogenesis by such agents as a sole causative factor. Further, based on a hypothesized lower sensitivity of humans to this MOA, prior reviews have concluded that rodent hepatocarcinogenesis by PPAR-α agonists is irrelevant to human carcinogenic risk. Data synthesis Herein, we review recent studies that experimentally challenge the PPAR-α activation MOA hypothesis, providing evidence that DEHP is hepatocarcinogenic in PPAR-α–null mice and that the MOA but not hepatocarcinogenesis is evoked by PPAR-α activation in a transgenic mouse model. We further examine whether relative potency for PPAR-α activation or other steps in the MOA correlates with tumorigenic potency. In addition, for most PPAR-α agonists of environmental concern, available data are insufficient to characterize relative human sensitivity to this rodent MOA or to induction of hepatocarcinogenesis. Conclusions Our review and analyses raise questions about the hypothesized PPAR-α activation MOA as a sole explanation for rodent hepatocarcinogenesis by PPAR-α agonists and therefore its utility as a primary basis for assessing human carcinogenic risk from the diverse compounds that activate PPAR-α. These findings have broad implications for how MOA hypotheses are developed, tested, and applied in human health risk assessment. We discuss alternatives to the current approaches to these key aspects of mechanistic data evaluation. PMID:20049115

  6. A network pharmacology study of Chinese medicine QiShenYiQi to reveal its underlying multi-compound, multi-target, multi-pathway mode of action.

    Directory of Open Access Journals (Sweden)

    Xiang Li

    Full Text Available Chinese medicine is a complex system guided by traditional Chinese medicine (TCM theories, which has proven to be especially effective in treating chronic and complex diseases. However, the underlying modes of action (MOA are not always systematically investigated. Herein, a systematic study was designed to elucidate the multi-compound, multi-target and multi-pathway MOA of a Chinese medicine, QiShenYiQi (QSYQ, on myocardial infarction. QSYQ is composed of Astragalus membranaceus (Huangqi, Salvia miltiorrhiza (Danshen, Panax notoginseng (Sanqi, and Dalbergia odorifera (Jiangxiang. Male Sprague Dawley rat model of myocardial infarction were administered QSYQ intragastrically for 7 days while the control group was not treated. The differentially expressed genes (DEGs were identified from myocardial infarction rat model treated with QSYQ, followed by constructing a cardiovascular disease (CVD-related multilevel compound-target-pathway network connecting main compounds to those DEGs supported by literature evidences and the pathways that are functionally enriched in ArrayTrack. 55 potential targets of QSYQ were identified, of which 14 were confirmed in CVD-related literatures with experimental supporting evidences. Furthermore, three sesquiterpene components of QSYQ, Trans-nerolidol, (3S,6S,7R-3,7,11-trimethyl-3,6-epoxy-1,10-dodecadien-7-ol and (3S,6R,7R-3,7,11-trimethyl-3,6-epoxy-1,10-dodecadien-7-ol from Dalbergia odorifera T. Chen, were validated experimentally in this study. Their anti-inflammatory effects and potential targets including extracellular signal-regulated kinase-1/2, peroxisome proliferator-activated receptor-gamma and heme oxygenase-1 were identified. Finally, through a three-level compound-target-pathway network with experimental analysis, our study depicts a complex MOA of QSYQ on myocardial infarction.

  7. Some notes on taxonomic methodology

    NARCIS (Netherlands)

    Hammen, van der L.

    1986-01-01

    The present paper constitutes an introduction to taxonomic methodology. After an analysis of taxonomic practice, and a brief survey of kinds of attributes, the paper deals with observation, description, comparison, arrangement and classification, hypothesis construction, deduction, model,

  8. Taxonomic revision of Geesinkorchis (Coelogyninae; Epidendroideae; Orchidaceae)

    NARCIS (Netherlands)

    Hsu, Shih-Chung; Gravendeel, B.; Vogel, de E.F.

    2005-01-01

    An updated taxonomic description of the orchid genus Geesinkorchis and a new identification key are given in addition to a distribution map, photographs and analytical drawings. Two new species (G. quadricarinata and G. breviunguiculata) are described from Borneo and Sumatra, respectively.

  9. Analysis of the anti-inflammatory and chemopreventive potential and description of the antimutagenic mode of action of the Annona crassiflora methanolic extract.

    Science.gov (United States)

    Rocha, Roberta Schroder; Kassuya, Candida Aparecida Leite; Formagio, Anelise Samara Nazari; Mauro, Mariana de Oliveira; Andrade-Silva, Magaiver; Monreal, Antonio Carlos Duenhas; Cunha-Laura, Andréa Luiza; Vieira, Maria do Carmo; Oliveira, Rodrigo Juliano

    2016-01-01

    Annona crassiflora Mart. (Annonaceae) is a medicinal plant that is widely used in folk medicine, which leads to its investigation as a potential source of new pharmacological principles. This study describes the anti-inflammatory, antiallodynic, and antimutagenic/chemopreventive activities of the leaves A. crassiflora methanolic extract. Its antimutagenic mode of action was analyzed in a plant or animal experimental model. Total flavonoids were quantified by spectrophotometry at 415 nm and its composition was analyzed by (1)H NMR spectra. Animals received orally, 30, 100, and 300 mg/kg of extract in both tests, carrageenan-induced paw edema and myeloperoxidase activity. Animals were treated with 100 and 300 mg/kg, in all the analyzed tests, pleural cell migration and protein exudation, carrageenan-induced cell migration into the pouch, induction of joint inflammation and carrageenan-induced allodynia response in the mouse paw. To evaluate the antimutagenic/chemopreventive activity through the Allium cepa test, we used 5, 10, and 15 mg/L of extract, and for the micronucleus test in the peripheral blood, we used the dose of 15 mg/kg. The fractionation of the ethyl acetate (EA) fraction, resulting from the partition of the methanol extract of the A. crassiflora, afforded through chromatographic methods resulted in the isolation of kaempferol 3-O-β-glucoside and kaempferol 3-O-β-diglucoside. Oral treatment with 100 and 300 mg/kg of extract significantly inhibited the carrageenan-induced edema formation, with inhibitions of 53 ± 7% and 47 ± 10%; in MPO activity, the observed inhibitions were 60 ± 7% for 100 mg/kg treatment and 63 ± 7% for 300 mg/kg. The ACME reduced significantly the total leukocytes (an inhibition of 78 ± 9% with 100 mg/kg and 90 ± 7% with 300 mg/kg) and protein levels (approximately 100% inhibition with both doses) in the pleurisy model. In carrageenan-induced leukocyte migration into the pouch, the extract inhibited leukocyte migration only

  10. Taxonomic distribution, repeats, and functions of the S1 domain-containing proteins as members of the OB-fold family.

    Science.gov (United States)

    Deryusheva, Evgeniia I; Machulin, Andrey V; Selivanova, Olga M; Galzitskaya, Oxana V

    2017-04-01

    Proteins of the nucleic acid-binding proteins superfamily perform such functions as processing, transport, storage, stretching, translation, and degradation of RNA. It is one of the 16 superfamilies containing the OB-fold in protein structures. Here, we have analyzed the superfamily of nucleic acid-binding proteins (the number of sequences exceeds 200,000) and obtained that this superfamily prevalently consists of proteins containing the cold shock DNA-binding domain (ca. 131,000 protein sequences). Proteins containing the S1 domain compose 57% from the cold shock DNA-binding domain family. Furthermore, we have found that the S1 domain was identified mainly in the bacterial proteins (ca. 83%) compared to the eukaryotic and archaeal proteins, which are available in the UniProt database. We have found that the number of multiple repeats of S1 domain in the S1 domain-containing proteins depends on the taxonomic affiliation. All archaeal proteins contain one copy of the S1 domain, while the number of repeats in the eukaryotic proteins varies between 1 and 15 and correlates with the protein size. In the bacterial proteins, the number of repeats is no more than 6, regardless of the protein size. The large variation of the repeat number of S1 domain as one of the structural variants of the OB-fold is a distinctive feature of S1 domain-containing proteins. Proteins from the other families and superfamilies have either one OB-fold or change slightly the repeat numbers. On the whole, it can be supposed that the repeat number is a vital for multifunctional activity of the S1 domain-containing proteins. Proteins 2017; 85:602-613. © 2016 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Distributional data and taxonomic notes on the flea Strepsylla (Siphonaptera: Ctenophthalmidae: Neopsyllinae: Phalacropsyllini Datos de distribución y notas taxonómicas de las especies de Strepsylla (Siphonaptera: Ctenophthalmidae: Neopsyllinae: Phalacropsyllini

    Directory of Open Access Journals (Sweden)

    Roxana Acosta

    2011-12-01

    Full Text Available Strepsylla Traub, 1950 is considered a New World flea genus, parasitizing, in most cases, species of Muridae, particularly peromyscines. Thirteen species of Strepsylla are addressed with respect to their taxonomic characters, host preferences and geographic distribution. A detailed list of material is included.Strepsylla Traub, 1950 es considerado un género de pulgas del nuevo mundo, que en la mayoría de los casos parasitan múridos, particularmente peromisinos. Se comentan algunos de los caracteres taxonómicos, preferencia de huéspedes, distribución geográfica y el material examinado de las 13 especies del género.

  12. A taxonomic synopsis of Altingiaceae with nine new combinations

    OpenAIRE

    Ickert-Bond, Stefanie M.; Wen, Jun

    2013-01-01

    Abstract A taxonomic synopsis of the Altingiaceae is presented, including the taxonomic enumeration and distribution of 15 recognized species based on studies of 1,500 specimens from 24 herbaria throughout the distributional range of the taxa. Previous phylogenetic analyses based on several molecular markers have shown that Altingia and Semiliquidambar are nested within Liquidambar. All Altingia and Semiliquidambar species are now formally transferred to Liquidambar, which has the nomenclatur...

  13. Whole genome mRNA transcriptomics analysis reveals different modes of action of the diarrheic shellfish poisons okadaic acid and dinophysis toxin-1 versus azaspiracid-1 in Caco-2 cells.

    Science.gov (United States)

    Bodero, Marcia; Hoogenboom, Ron L A P; Bovee, Toine F H; Portier, Liza; de Haan, Laura; Peijnenburg, Ad; Hendriksen, Peter J M

    2018-02-01

    A study with DNA microarrays was performed to investigate the effects of two diarrhetic and one azaspiracid shellfish poison, okadaic acid (OA), dinophysistoxin-1 (DTX-1) and azaspiracid-1 (AZA-1) respectively, on the whole-genome mRNA expression of undifferentiated intestinal Caco-2 cells. Previously, the most responding genes were used to develop a dedicated array tube test to screen shellfish samples on the presence of these toxins. In the present study the whole genome mRNA expression was analyzed in order to reveal modes of action and obtain hints on potential biomarkers suitable to be used in alternative bioassays. Effects on key genes in the most affected pathways and processes were confirmed by qPCR. OA and DTX-1 induced almost identical effects on mRNA expression, which strongly indicates that OA and DTX-1induce similar toxic effects. Biological interpretation of the microarray data indicates that both compounds induce hypoxia related pathways/processes, the unfolded protein response (UPR) and endoplasmic reticulum (ER) stress. The gene expression profile of AZA-1 is different and shows increased mRNA expression of genes involved in cholesterol synthesis and glycolysis, suggesting a different mode of action for this toxin. Future studies should reveal whether identified pathways provide suitable biomarkers for rapid detection of DSPs in shellfish. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Does taxonomic diversity in indicator groups influence their effectiveness in identifying priority areas for species conservation?

    DEFF Research Database (Denmark)

    Bladt, Jesper Stentoft; Larsen, Frank Wugt; Rahbek, Carsten

    2008-01-01

    the taxonomic diversity in species indicator groups influence their effectiveness in the identification of priority areas for species conservation. We tested whether indicator groups comprising a higher taxonomic diversity (i.e. indicator groups consisting of species from many different taxonomic groups...... not consistently increase the coverage of target species than when using less taxonomically diverse indicator groups. However, indicator groups chosen solely from one taxon were outperformed by taxonomically diverse groups. Second, we found that taxonomic diversity of the indicator did not influence the taxonomic...... diversity of the covered target species (in terms of number of represented families, orders, etc.) Thus, taxonomic diversity per se only had a marginal influence on the performance of indicator groups. Distributional characteristics, such as the proportion of species with narrow range sizes, had a larger...

  15. Distribution and Taxonomic Significance of Secondary Metabolites Occurring in the Methanol Extracts of the Stonecrops (Sedum L., Crassulaceae) from the Central Balkan Peninsula.

    Science.gov (United States)

    Stojanovic, Gordana S; Jovanović, Snežana C; Zlatković, Bojan K

    2015-06-01

    The present study is engaged in the chemical composition of methanol extracts of Sedum taxa from the central part of the Balkan Peninsula, and representatives from other genera of Crassulaceae (Crassula, Echeveria and Kalanchoe) considered as out-groups. The chemical composition of extracts was determined by HPLC analysis, according to retention time of standards and characteristic absorption spectra of components. Identified components were considered as original variables with possible chemotaxonomic significance. Relationships of examined plant samples were investigated by agglomerative hierarchical cluster analysis (AHC). The obtained results showed how the distribution of methanol extract components (mostly phenolics) affected grouping of the examined samples. The obtained clustering showed satisfactory grouping of the examined samples, among which some representatives of the Sedum series, Rupestria and Magellensia, are the most remote. The out-group samples were not clearly singled out with regard to Sedum samples as expected; this especially applies to samples of Crassula ovata and Echeveria lilacina, while Kalanchoe daigremontiana was more separated from most of the Sedum samples.

  16. A Taxonomic Search Engine: Federating taxonomic databases using web services

    Directory of Open Access Journals (Sweden)

    Page Roderic DM

    2005-03-01

    Full Text Available Abstract Background The taxonomic name of an organism is a key link between different databases that store information on that organism. However, in the absence of a single, comprehensive database of organism names, individual databases lack an easy means of checking the correctness of a name. Furthermore, the same organism may have more than one name, and the same name may apply to more than one organism. Results The Taxonomic Search Engine (TSE is a web application written in PHP that queries multiple taxonomic databases (ITIS, Index Fungorum, IPNI, NCBI, and uBIO and summarises the results in a consistent format. It supports "drill-down" queries to retrieve a specific record. The TSE can optionally suggest alternative spellings the user can try. It also acts as a Life Science Identifier (LSID authority for the source taxonomic databases, providing globally unique identifiers (and associated metadata for each name. Conclusion The Taxonomic Search Engine is available at http://darwin.zoology.gla.ac.uk/~rpage/portal/ and provides a simple demonstration of the potential of the federated approach to providing access to taxonomic names.

  17. A Taxonomic Search Engine: federating taxonomic databases using web services.

    Science.gov (United States)

    Page, Roderic D M

    2005-03-09

    The taxonomic name of an organism is a key link between different databases that store information on that organism. However, in the absence of a single, comprehensive database of organism names, individual databases lack an easy means of checking the correctness of a name. Furthermore, the same organism may have more than one name, and the same name may apply to more than one organism. The Taxonomic Search Engine (TSE) is a web application written in PHP that queries multiple taxonomic databases (ITIS, Index Fungorum, IPNI, NCBI, and uBIO) and summarises the results in a consistent format. It supports "drill-down" queries to retrieve a specific record. The TSE can optionally suggest alternative spellings the user can try. It also acts as a Life Science Identifier (LSID) authority for the source taxonomic databases, providing globally unique identifiers (and associated metadata) for each name. The Taxonomic Search Engine is available at http://darwin.zoology.gla.ac.uk/~rpage/portal/ and provides a simple demonstration of the potential of the federated approach to providing access to taxonomic names.

  18. Bacteriocins from Lactobacillus plantarum production, genetic organization and mode of action: produção, organização genética e modo de ação Bacteriocinas de Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Svetoslav D. Todorov

    2009-06-01

    Full Text Available Bacteriocins are biologically active proteins or protein complexes that display a bactericidal mode of action towards usually closely related species. Numerous strains of bacteriocin producing Lactobacillus plantarum have been isolated in the last two decades from different ecological niches including meat, fish, fruits, vegetables, and milk and cereal products. Several of these plantaricins have been characterized and the aminoacid sequence determined. Different aspects of the mode of action, fermentation optimization and genetic organization of the bacteriocin operon have been studied. However, numerous of bacteriocins produced by different Lactobacillus plantarum strains have not been fully characterized. In this article, a brief overview of the classification, genetics, characterization, including mode of action and production optimization for bacteriocins from Lactic Acid Bacteria in general, and where appropriate, with focus on bacteriocins produced by Lactobacillus plantarum, is presented.Bacteriocinas são proteínas ou complexos protéicos biologicamente ativos que apresentam atividade bactericida contra espécies relacionadas. Nas ultimas duas décadas, várias cepas de Lactobacillus plantarum produtoras de bacteriocinas foram isoladas de diferentes nichos ecológicos como carnes, peixes, frutas, vegetais e produtos lácteos e de cereais. Várias plantaricinas foram caracterizadas e suas seqüências de aminoácidos determinadas. Diferentes aspectos do modo de ação, otimização da fermentação e organização genética já foram estudados. Entretanto, muitas bacteriocinas produzidas por diferentes cepas de Lactobacillus plantarum ainda não foram completamente caracterizadas.Nesse artigo, apresenta-se uma breve revisão sobre a classificação, genética, caracterização, modo de ação, e otimização da produção de bacteriocinas de bactérias láticas em geral, e, quando apropriado, de bacteriocinas de Lactobacillus plantarum.

  19. Composición taxonómica, distribución y bionomía de la familia Noteridae (Coleoptera: Adephaga en Cuba Taxonomic composition, distribution and bionomics of the family Noteridae (Coleoptera: Adephaga in Cuba

    Directory of Open Access Journals (Sweden)

    Yoandri S. Megna

    2006-07-01

    Full Text Available La presente investigación analiza la composición taxonómica, distribución y bionomía de los notéridos registrados en Cuba, y se brinda una clave para su identificación. El estudio se realizó sobre la base de datos bibliográficos a nivel regional y nacional, así como del material colectado en diferentes localidades del país. Este trabajo permitió definir la lista de especies, su distribución por distritos fitogeográficos y los aspectos más generales de su bionomía. Se determinó que la familia Noteridae está compuesta por cinco géneros ( Hydrocanthus Say, Mesonoterus Sharp , Suphis Aubé , Suphisellus Crotch y Notomicrus Sharp y 10 especies, de las cuales Suphisellus tenuicornis (Chevrolat es endémica, e Hydrocanthus advena Sharp no está confirmada. Las especies registradas están distribuidas en 11 (28,2% de los 39 distritos fitogeográficos establecidos. El distrito de mayor riqueza de especies es el Nº 15 (Planicie Centro-Occidental, con ocho especies. La especie más ampliamente distribuida es Notomicrus sharpi J. Balfour-Browne, reportada para seis (15,4% distritos. Los datos bionómicos muestran que los notéridos tienen preferencia por los hábitats lénticos y permanentes, de aguas dulces y turbias, ubicados en zonas bajas y soleadas con abundante vegetación acuática.The present work deals with the taxonomic composition, distribution, and bionomics of noterids from Cuba . Our research is based both on local and regional references on this family found in the literature, and on the identification of specimens collected from several localities of the country. We present a taxonomical list and a key to identify the species occurring in Cuba , along with their distribution regarding phytogeographic districts, and bionomical information. In Cuba , the family Noteridae is composed of five genera ( Hydrocanthus Say, Mesonoterus Sharp, Suphis Aubé , Suphisellus Crotch, and Notomicrus Sharp and 10 species, of which

  20. Partitioning taxonomic diversity of aquatic insect assemblages ...

    Science.gov (United States)

    Biological diversity can be divided into: alpha (α, local), beta (β, difference in assemblage composition among locals), and gamma (γ, total diversity). We assessed the partitioning of taxonomic diversity of Ephemeroptera, Plecoptera and Trichoptera (EPT) and of functional feeding groups (FFG) in Neotropical Savanna (southeastern Brazilian Cerrado) streams. To do so, we considered three diversity components: stream site (α), among stream sites (β1), and among hydrologic units (β2). We also evaluated the association of EPT genera composition with heterogeneity in land use, instream physical habitat structure, and instream water quality variables. The percent of EPT taxonomic α diversity (20.7%) was lower than the β1 and β2 diversities (53.1% and 26.2%, respectively). The EPT FFG α diversity (26.5%) was lower than the β1 diversity (55.8%) and higher than the β2 (17.7%) diversity. The collector-gatherer FFG was predominant and had the greatest β diversity among stream sites (β1, 55.8%). Our findings support the need for implementing regional scale conservation strategies in the Cerrado biome, which has been degraded by anthropogenic activities. Using adaptations of the US EPA’s National Aquatic Resource Survey (NARS) designs and methods, Ferreira and colleagues examined the distribution of taxonomic and functional diversity of aquatic insects among basins, stream sites within basins, and within stream sample reaches. They sampled 160 low-order stre

  1. Distribution patterns of Chilean shallow-water sea anemones (Cnidaria: Anthozoa: Actiniaria, Corallimorpharia; with a discussion of the taxonomic and zoogeographic relationships between the actinofauna of the South East Pacific, the South West Atlantic and the Antarctic

    Directory of Open Access Journals (Sweden)

    Verena Häussermann

    2005-12-01

    Full Text Available The first complete zoogeographical analysis of Chilean shallow water sea anemones (Actiniaria and Corallimorpharia and their taxonomic relations with neighbouring faunas is provided, based on extensive recent sampling in combination with a literature review. Between 1994 and 2004, we collected more than 1000 specimens of 32 distinct species of Actiniaria and Corallimorpharia at more than 100 sites along the Chilean coast between Arica (18°30’S; 70°19’W and the Straits of Magellan (53°36’S 70°56’W. Sampling was done in the intertidal during low tides and in the subtidal by means of SCUBA diving down to depths of 40 m. The northern part of the Chilean fjord region showed the highest number of species (23. Our results contradict an abrupt general change in the marine faunal composition at 42°S, instead showing the continuation of species of the exposed coast and the joining of fjord species due to the availability of additional habitats in the richly structured fjord region south of 42°S, and also to eurybathy. The southern distribution limits of the species we found in northern and central Chile show only one significant concentration around the Peninsula Taitao (approx. 48°S. This either indicates a zoogeographic barrier for shallow water species at the Peninsula Taitao, or is a sampling artifact caused by poor data from the region between the Peninsula Taitao and the Straits of Magellan. According to the literature, 18 of the 63 described Chilean sea anemones (Pacific Ocean can also be found in Argentina (Atlantic Ocean and 13 in the Antarctic. However, many records and statuses of the common species of the South East Pacific and the South West Atlantic/Antarctic are uncertain or doubtful and need revision or confirmation.

  2. Taxonomic and thematic semantic systems.

    Science.gov (United States)

    Mirman, Daniel; Landrigan, Jon-Frederick; Britt, Allison E

    2017-05-01

    Object concepts are critical for nearly all aspects of human cognition, from perception tasks like object recognition, to understanding and producing language, to making meaningful actions. Concepts can have 2 very different kinds of relations: similarity relations based on shared features (e.g., dog-bear), which are called "taxonomic" relations, and contiguity relations based on co-occurrence in events or scenarios (e.g., dog-leash), which are called "thematic" relations. Here, we report a systematic review of experimental psychology and cognitive neuroscience evidence of this distinction in the structure of semantic memory. We propose 2 principles that may drive the development of distinct taxonomic and thematic semantic systems: differences between which features determine taxonomic versus thematic relations, and differences in the processing required to extract taxonomic versus thematic relations. This review brings together distinct threads of behavioral, computational, and neuroscience research on semantic memory in support of a functional and neural dissociation, and defines a framework for future studies of semantic memory. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. Significando o risco sanitário: modos de atuação sobre o risco na vigilância sanitária / Meaning the health risk: modes of action on the risk in health surveillance

    Directory of Open Access Journals (Sweden)

    Ana Valesca Fernandes GIlson Silva

    2014-05-01

    Full Text Available Este estudo qualitativo, que utiliza o Interacionismo Simbólico como referencial teórico e a Teoria Fundamentada nos Dados como método, buscou compreender os modos de atuação sobre o risco. Sintetiza os significados do risco para os profissionais da Vigilância Sanitária (VISA e analisa os modos de atuação para o seu controle. A síntese é a sistematização das interpretações e significados do risco. A análise apresenta a existência de dois modos de atuação, permitindo empreender a aplicação do significado de risco no âmbito do domínio de um saber específico. Entre a identificação do risco e a intervenção existem processos que mesclam a racionalidade à subjetividade, a autoridade ao controle, a experiência ao conhecimento formal adquirido. O agir do profissional da VISA é constituído por conhecimentos, pela experiência adquirida, pelos contextos socioculturais e pelas interações que definem e redefinem os modos de atuar. As ações são baseadas nos significados do risco que se deslocam no plano da objetividade e da subjetividade, e a legislação é um importante instrumento de decisão e de persuasão. Embora ocorra um deslocamento para o uso do conhecimento e da experiência, é o arcabouço legal que imprime o que deve ou não ser controlado. ------------------------------------------------------------------------- This qualitative study that utilizes Symbolic Interactionism as a theoretical background and Grounded Theory as a method, sought to understand the modes of action about risk. It summarizes the meanings of risk to the professionals of Health Surveillance (HS, and analyses the modes of action to control it. The summary is the systematization of the in-terpretations and meanings of risk. The analysis shows the existence of two modes of ac-tion, allowing to undertake the application of the meaning of risk in the scope of domain of an specific knowledge. Between the risk identification and the

  4. Nacellidae limpets of the southern end of South America: taxonomy and distribution Lapas Nacellidae del extremo sur de Sudamérica: taxonomía y distribución

    Directory of Open Access Journals (Sweden)

    CLAUDIO VALDOVINOS

    2005-09-01

    Full Text Available Taxonomically, the Mollusca of the southern end of South America are moderately well known, but the literature is scattered, there is little information on their habitats, and distributional records are scarce for the Chilean archipelago lying between Chiloé Island (42° S and Tierra del Fuego (55° S. Although much is known about the biology and ecology of of some species of Nacellidae, the taxonomy of the group have been partially neglected, particularly in remote areas of the world such as the Chilean fjords. Therefore, this study aims to clarify the nomenclatural status, and establish the morphological characteristics and distribution of the Chilean Nacellidae. Especially, the following three objectives are pursued: (i to clarify the correct identity of existing species; (ii to describe of morphological details, highlighting the clear diagnostic characters of each species, and (iii to delimitate and discuss their geographical range in Chile. The examination of the Nacellidae of the Chilean fiords has resulted in the recognition of one species of Nacella (Nacella and seven species of Nacella (Patinigera, wherein the principal specific differences are in the shell (shape, thickness and color and in radular teeth morphology. The genus Nacella and its subgenus Patinigera are cold-water limpets, and are exclusively inhabitants of Subantarctic and Antarctic waters. The greater part of their range being subantarctic, but extending to the Antarctic by way of the Scotia Arc, and also ranging northward up the Chilean coast to at least Valparaiso at 33° S (only N. (P. clypeater. They apparently have their centre of distribution in the Magellanic Province of southern South America, corresponding to an area with a high degree of diversification (N. (N. mytilina, N. (P. chiloensis, N. (P. deaurata, N. (P. delicatissima, N. (P. flammea, N. (P. magellanica, N. (P. venosa, wherefrom the species tends to spread eastward, with a larval transport probably

  5. Bactericidal mode of action of plantaricin C

    NARCIS (Netherlands)

    González, Beatriz; Glaasker, Erwin; Kunji, Edmund R.S.; Driessen, Arnold J.M.; Suárez, Juan E.; Konings, Wil N.

    Plantaricin C is a bacteriocin produced by Lactobacillus plantarum LL441 that kills sensitive cells by acting on the cytoplasmic membrane. In contrast to its lack of impact on immune cells, plantaricin C dissipates the proton motive force and inhibits amino acid transport in sensitive cells. In

  6. Azelaic acid: Properties and mode of action.

    Science.gov (United States)

    Sieber, M A; Hegel, J K E

    2014-01-01

    Acne is a common skin disorder that can be problematic for adults as well as for adolescents. It has several key pathophysiological features such as follicular hyperkeratosis, elevated Propionibacterium acnes proliferation, and reactive inflammation, all of which should be targeted for an optimal outcome. Azelaic acid (AzA) has profound anti-inflammatory, antioxidative effects, and is bactericidal against a range of Gram-negative and Gram-positive microorganisms as well, including antibiotic-resistant bacterial strains. In addition, AzA's antikeratinizing effects are inhibitory toward comedones. AzA is effective overall in targeting multiple causes of acne and has been proven to be well tolerated in numerous clinical trials. © 2013 S. Karger AG, Basel.

  7. Chemical pesticides: mode of action and toxicology

    National Research Council Canada - National Science Library

    Stenersen, Jørgen

    2004-01-01

    ... responsibility for the validity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or me...

  8. Lactococcins : Mode of action, immunity and secretion

    NARCIS (Netherlands)

    Venema, K; Kok, J; Venema, Gerhardus

    1995-01-01

    Lactococcus lactis subsp. cremoris 9B4 produces three small (around 5kDa), heat-stable, non-lanthionine containing, membrane active bacteriocins. Amino acid uptake experiments and proton motive force measurements have indicated that these peptides most probably form pores in the cytoplasmic membrane

  9. Mode of action of nanoparticles against insects.

    Science.gov (United States)

    Benelli, Giovanni

    2018-04-03

    The employment of nanoparticles obtained through various synthesis routes as novel pesticides recently attracted high research attention. An impressive number of studies have been conducted to test their toxic potential against a wide number of arthropod pests and vectors, with major emphasis on mosquitoes and ticks. However, precise information on the mechanisms of action of nanoparticles against insects and mites are limited, with the noteworthy exception of silica, alumina, silver, and graphene oxide nanoparticles on insects, while no information is available for mites. Here, I summarize current knowledge about the mechanisms of action of nanoparticles against insects. Both silver and graphene oxide nanoparticles have a significant impact on insect antioxidant and detoxifying enzymes, leading to oxidative stress and cell death. Ag nanoparticles also reduced acetylcholinesterase activity, while polystyrene nanoparticles inhibited CYP450 isoenzymes. Au nanoparticles can act as trypsin inhibitors and disrupt development and reproduction. Metal nanoparticles can bind to S and P in proteins and nucleic acids, respectively, leading to a decrease in membrane permeability, therefore to organelle and enzyme denaturation, followed by cell death. Besides, Ag nanoparticles up- and downregulate key insect genes, reducing protein synthesis and gonadotrophin release, leading to developmental damages and reproductive failure. The toxicity of SiO 2 and Al 2 O 3 nanoparticles is due to their binding to the insect cuticle, followed by physico-sorption of waxes and lipids, leading to insect dehydration. In the final section, insect nanotoxicology research trends are critically discussed, outlining major challenges to predict the ecotoxicological consequences arising from the real-world use of nanoparticles as pesticides.

  10. Nanoscaled boehmites' modes of action in a polymer and its carbon fiber reinforced plastic under compression load; Wirkungsweisen nanoskaliger Boehmite in einem Polymer und seinem Kohlenstofffaserverbund unter Druckbelastung

    Energy Technology Data Exchange (ETDEWEB)

    Arlt, Christine

    2011-07-01

    Increasing ecological awareness as well as quality and safety demands, which are present, for instance, in the aerospace and automotive sectors, lead to the need to use more sophisticated and more effective materials. For that purpose, laminates of carbon fiber reinforced plastic (CFRP), which are manufactured by injection technology, are reinforced with boehmite particles. This doping strengthens the laminates, whose original properties are weaker than prepregs. Besides the shear strength, compression strength and the damage tolerance, the mode of action of the nanoparticles in resin and in CRFP is also analyzed. It thereby reveals that the hydroxyl groups and even more a taurine modification of the boehmites' surface after the elementary polymer morphology. Consequently a new flow and reaction comportment, lower glass transition temperatures and shrinkage, as well as a changed mechanical behavior occur. Due to a structural upgrading of the matrix (higher shear stiffness, reduced residual stress), a better fiber-matrix adhesion, and differing crack paths, the boehmite nanoparticles move the degradation barrier of the material to higher loadings, thus resulting in considerably upgraded new CFRP. (orig.)

  11. Identification and mode of action of 5-hydroxymethyl-2-furfural (5-hmf) and 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) as potent xanthine oxidase inhibitors in vinegars.

    Science.gov (United States)

    Lin, Shu-Mei; Wu, Jin-Yi; Su, Chien; Ferng, Sophia; Lo, Chih-Yu; Chiou, Robin Y-Y

    2012-10-03

    Vinegars have been used as an alternative remedy for treating gout, but the scientific basis remains to be elucidated. In this study, seven commercial vinegars and one laboratory-prepared red-koji vinegar were evaluated for the inhibitory activity of xanthine oxidase (XO), a critical enzyme catalyzing uric acid formation. Red-koji vinegar exhibited potent xanthine oxidase inhibitory (XOI) activity and was used for isolating active compounds. The substances under two peaks with XOI activity from HPLC were identified as 5-hydroxymethyl-2-furfural (5-HMF) and 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA), by LC-MS-MS and NMR. The XO half-maximal inhibitory concentrations (IC(50)) of 5-HMF and MTCA were 168 and 860 μg/mL, respectively. In further mode-of-action analysis, the inhibitory mechanism of each compound was elucidated at the IC(50) level in the presence of various concentrations of xanthine as the substrate. The following Michaelis-Menten kinetics analysis of XO inhibition revealed uncompetitive and competitive patterns for 5-HMF and MTCA, respectively.

  12. A taxonomic revision of Germainia (Andropogoneae: Poaceae) in Thailand

    NARCIS (Netherlands)

    Teerawatananon, A.; Sungkaew, S.; Boontia, V.; Hodkinson, T.R.

    2012-01-01

    A taxonomic revision of the genus Germainia (Andropogoneae, Poaceae) in Thailand is presented based on herbarium and field studies, including evidence from morphology, habitats and geographical distribution. Six of the nine recognized Germainia species are found in Thailand. We include a key to the

  13. Taxonomic studies of nodulated leguminous weeds from the flora of ...

    African Journals Online (AJOL)

    Taxonomic studies of nodulated leguminous weeds from the flora of North Western part (Dera Ismail Khan) of Pakistan. ... Results were systematically arranged by alphabetic order of botanical names, followed by synonyms (if any), description of the plant, flowering and fruiting period, type, local and general distribution.

  14. NODC Standard Product: NODC Taxonomic Code on CD-ROM (NODC Accession 0050418)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The content of the NODC Taxonomic Code, Version 8 CD-ROM (CD-ROM NODC-68) distributed by NODC is archived in this accession. Version 7 of the NODC Taxonomic Code...

  15. Global taxonomic diversity of living reptiles.

    Directory of Open Access Journals (Sweden)

    Daniel Pincheira-Donoso

    Full Text Available Reptiles are one of the most ecologically and evolutionarily remarkable groups of living organisms, having successfully colonized most of the planet, including the oceans and some of the harshest and more environmentally unstable ecosystems on earth. Here, based on a complete dataset of all the world's diversity of living reptiles, we analyse lineage taxonomic richness both within and among clades, at different levels of the phylogenetic hierarchy. We also analyse the historical tendencies in the descriptions of new reptile species from Linnaeus to March 2012. Although (non-avian reptiles are the second most species-rich group of amniotes after birds, most of their diversity (96.3% is concentrated in squamates (59% lizards, 35% snakes, and 2% amphisbaenians. In strong contrast, turtles (3.4%, crocodilians (0.3%, and tuataras (0.01% are far less diverse. In terms of species discoveries, most turtles and crocodilians were described early, while descriptions of lizards, snakes and amphisbaenians are multimodal with respect to time. Lizard descriptions, in particular, have reached unprecedented levels during the last decade. Finally, despite such remarkably asymmetric distributions of reptile taxonomic diversity among groups, we found that the distributions of lineage richness are consistently right-skewed, with most clades (monophyletic families and genera containing few lineages (monophyletic genera and species, respectively, while only a few have radiated greatly (notably the families Colubridae and Scincidae, and the lizard genera Anolis and Liolaemus. Therefore, such consistency in the frequency distribution of richness among clades and among phylogenetic levels suggests that the nature of reptile biodiversity is fundamentally fractal (i.e., it is scale invariant. We then compared current reptile diversity with the global reptile diversity and taxonomy known in 1980. Despite substantial differences in the taxonomies (relative to 2012, the

  16. Global Taxonomic Diversity of Living Reptiles

    Science.gov (United States)

    Pincheira-Donoso, Daniel; Bauer, Aaron M.; Meiri, Shai; Uetz, Peter

    2013-01-01

    Reptiles are one of the most ecologically and evolutionarily remarkable groups of living organisms, having successfully colonized most of the planet, including the oceans and some of the harshest and more environmentally unstable ecosystems on earth. Here, based on a complete dataset of all the world’s diversity of living reptiles, we analyse lineage taxonomic richness both within and among clades, at different levels of the phylogenetic hierarchy. We also analyse the historical tendencies in the descriptions of new reptile species from Linnaeus to March 2012. Although (non-avian) reptiles are the second most species-rich group of amniotes after birds, most of their diversity (96.3%) is concentrated in squamates (59% lizards, 35% snakes, and 2% amphisbaenians). In strong contrast, turtles (3.4%), crocodilians (0.3%), and tuataras (0.01%) are far less diverse. In terms of species discoveries, most turtles and crocodilians were described early, while descriptions of lizards, snakes and amphisbaenians are multimodal with respect to time. Lizard descriptions, in particular, have reached unprecedented levels during the last decade. Finally, despite such remarkably asymmetric distributions of reptile taxonomic diversity among groups, we found that the distributions of lineage richness are consistently right-skewed, with most clades (monophyletic families and genera) containing few lineages (monophyletic genera and species, respectively), while only a few have radiated greatly (notably the families Colubridae and Scincidae, and the lizard genera Anolis and Liolaemus). Therefore, such consistency in the frequency distribution of richness among clades and among phylogenetic levels suggests that the nature of reptile biodiversity is fundamentally fractal (i.e., it is scale invariant). We then compared current reptile diversity with the global reptile diversity and taxonomy known in 1980. Despite substantial differences in the taxonomies (relative to 2012), the patterns of

  17. Alleviative Effects of a Kampo (a Japanese Herbal Medicine “Maoto (Ma-Huang-Tang” on the Early Phase of Influenza Virus Infection and Its Possible Mode of Action

    Directory of Open Access Journals (Sweden)

    Takayuki Nagai

    2014-01-01

    Full Text Available A Kampo medicine, maoto, has been prescribed in an early phase of influenza-like illness and used for a treatment of influenza clinically in Japan these days. However, the efficacy of maoto against the virus infection remains to be elucidated. This study was conducted to evaluate the alleviative effects of maoto against early phase of influenza virus infection and its preliminary mode of actions through immune systems. When maoto (0.9 and 1.6 g/kg/day was orally administered to A/J mice on upper respiratory tract infection of influenza virus A/PR/8/34 from 4 hours to 52 hours postinfection (p.i. significant antipyretic effect was shown in comparison with water-treated control. Administration of maoto (0.8 and 1.3 g/kg/day significantly decreased the virus titers in both nasal (NLF and bronchoalveolar lavage fluids (BALF at 52 hours p.i., and significantly increased the anti-influenza virus IgM, IgA, and IgG1 antibody titers in NLF, BALF, and serum, respectively. Maoto also increased significantly the influenza virus-bound IgG1 and IgM antibody titers in serum and the virus-bound IgM antibody titer in even the BALF of uninfected A/J mice. These results indicate that maoto exerts antipyretic activity in influenza virus-infected mice and virus reducing effect at an early phase of the infection through probably augmentation of the virus-bound natural antibodies.

  18. The mode of action of 2-(thiazol-2-ylthio)-1beta-methylcarbapenems against Pseudomonas aeruginosa: the impact of outer membrane permeability and the contribution of MexAB-OprM efflux system.

    Science.gov (United States)

    Eguchi, Ken; Ueda, Yutaka; Kanazawa, Katsunori; Sunagawa, Makoto; Gotoh, Naomasa

    2007-02-01

    The mode of action of a series of 2-(4-dihydropyrrolylthiazol-2-ylthio) and 2-(4-tetrahydropyridinylthiazol-2-ylthio)-1beta-methylcarbapenem analogues against Pseudomonas aeruginosa was investigated with regard to contributions of the affinity for penicillin binding proteins (PBPs), the outer membrane permeability, and the effect of the MexAB-OprM efflux system. In this series of carbapenems, the introduction of a substituent in C-2 side chain with a change in physicochemical properties affected the antipseudomonal activity depending on the molecular weight. However, these structural modifications did not affect the affinity for pseudomonal PBPs significantly. It was confirmed that the affinity for PBPs was not an important determinant of the antipseudomonal activity of this series of carbapenems. OprD porin-deficiency did not affect antipseudomonal activity either. On the other hand, the MIC of these carbapenems against P. aeruginosa significantly decreased in the presence of outer membrane permeabilizer. This result strongly suggests that the cause of the relatively low antipseudomonal activity of these carbapanems is their low permeability through the outer membrane of P. aeruginosa. And also, in the presence of outer membrane permeabilizer, the MICs against MexAB-OprM deficient mutants remarkably decreased and were very close to the value of the IC(50) for pseudomonal PBPs. From this result, it was clear that the effect of the MexAB-OprM efflux system was also an important determinant of antipseudomonal activity of these carbapenems. In conclusion, the major determinants of the antipseudomonal activity of the 2-(thiazol-2-ylthio)-1beta-methylcarbapenems are the outer membrane permeability and the effect of the MexAB-OprM efflux system, not the affinity for pseudomonal PBPs.

  19. Exploring historical trends using taxonomic name metadata

    Directory of Open Access Journals (Sweden)

    Schenk Ryan

    2008-05-01

    Full Text Available Abstract Background Authority and year information have been attached to taxonomic names since Linnaean times. The systematic structure of taxonomic nomenclature facilitates the ability to develop tools that can be used to explore historical trends that may be associated with taxonomy. Results From the over 10.7 million taxonomic names that are part of the uBio system 4, approximately 3 million names were identified to have taxonomic authority information from the years 1750 to 2004. A pipe-delimited file was then generated, organized according to a Linnaean hierarchy and by years from 1750 to 2004, and imported into an Excel workbook. A series of macros were developed to create an Excel-based tool and a complementary Web site to explore the taxonomic data. A cursory and speculative analysis of the data reveals observable trends that may be attributable to significant events that are of both taxonomic (e.g., publishing of key monographs and societal importance (e.g., world wars. The findings also help quantify the number of taxonomic descriptions that may be made available through digitization initiatives. Conclusion Temporal organization of taxonomic data can be used to identify interesting biological epochs relative to historically significant events and ongoing efforts. We have developed an Excel workbook and complementary Web site that enables one to explore taxonomic trends for Linnaean taxonomic groupings, from Kingdoms to Families.

  20. Exploring historical trends using taxonomic name metadata.

    Science.gov (United States)

    Sarkar, Indra Neil; Schenk, Ryan; Norton, Catherine N

    2008-05-13

    Authority and year information have been attached to taxonomic names since Linnaean times. The systematic structure of taxonomic nomenclature facilitates the ability to develop tools that can be used to explore historical trends that may be associated with taxonomy. From the over 10.7 million taxonomic names that are part of the uBio system 4, approximately 3 million names were identified to have taxonomic authority information from the years 1750 to 2004. A pipe-delimited file was then generated, organized according to a Linnaean hierarchy and by years from 1750 to 2004, and imported into an Excel workbook. A series of macros were developed to create an Excel-based tool and a complementary Web site to explore the taxonomic data. A cursory and speculative analysis of the data reveals observable trends that may be attributable to significant events that are of both taxonomic (e.g., publishing of key monographs) and societal importance (e.g., world wars). The findings also help quantify the number of taxonomic descriptions that may be made available through digitization initiatives. Temporal organization of taxonomic data can be used to identify interesting biological epochs relative to historically significant events and ongoing efforts. We have developed an Excel workbook and complementary Web site that enables one to explore taxonomic trends for Linnaean taxonomic groupings, from Kingdoms to Families.

  1. Flexible taxonomic assignment of ambiguous sequencing reads

    Directory of Open Access Journals (Sweden)

    Jansson Jesper

    2011-01-01

    Full Text Available Abstract Background To characterize the diversity of bacterial populations in metagenomic studies, sequencing reads need to be accurately assigned to taxonomic units in a given reference taxonomy. Reads that cannot be reliably assigned to a unique leaf in the taxonomy (ambiguous reads are typically assigned to the lowest common ancestor of the set of species that match it. This introduces a potentially severe error in the estimation of bacteria present in the sample due to false positives, since all species in the subtree rooted at the ancestor are implicitly assigned to the read even though many of them may not match it. Results We present a method that maps each read to a node in the taxonomy that minimizes a penalty score while balancing the relevance of precision and recall in the assignment through a parameter q. This mapping can be obtained in time linear in the number of matching sequences, because LCA queries to the reference taxonomy take constant time. When applied to six different metagenomic datasets, our algorithm produces different taxonomic distributions depending on whether coverage or precision is maximized. Including information on the quality of the reads reduces the number of unassigned reads but increases the number of ambiguous reads, stressing the relevance of our method. Finally, two measures of performance are described and results with a set of artificially generated datasets are discussed. Conclusions The assignment strategy of sequencing reads introduced in this paper is a versatile and a quick method to study bacterial communities. The bacterial composition of the analyzed samples can vary significantly depending on how ambiguous reads are assigned depending on the value of the q parameter. Validation of our results in an artificial dataset confirm that a combination of values of q produces the most accurate results.

  2. Mediated effect of ultrasound treated Diclofenac on mussel hemocytes: First evidence for the involvement of respiratory burst enzymes in the induction of DCF-mediated unspecific mode of action.

    Science.gov (United States)

    Toufexi, Eirini; Dailianis, Stefanos; Vlastos, Dimitris; Manariotis, Ioannis D

    2016-06-01

    The present study investigates the toxic behavior of diclofenac (DCF) before and after its ultrasound (US) treatment, as well as the involvement of intracellular target molecules, such as NADPH oxidase and NO synthase, in the DCF-induced adverse effects on hemocytes of mussel Mytilus galloprovincialis. In this context, appropriate volumes (350 and 500mL) of DCF solutions (at concentrations of 2, 2.5, 5 and 10mgL(-1)) were treated under different ultrasound operating conditions (frequency at 582 and 862kHz, electric power density at 133 and 167W) for assessing US method efficiency. In parallel, DCF and US DCF-mediated cytotoxic (in terms of cell viability measured with the use of neutral red uptake/NRU method), oxidative (in terms of superoxide anions/(.)O2(-), nitric oxides such as NO2(-) and lipid peroxidation products, such as malondialdehyde/MDA content) and genotoxic (DNA damage measured by the use of Comet assay method) effects were investigated in hemocytes exposed for 1h to 5, 10 and 100ngL(-1) and 1, 10 and 20μgL(-1) of DCF. The involvement of NADPH oxidase and NO synthase to the DCF-induced toxicity was further investigated by the use of 10μΜ L-NAME, a NO synthase inhibitor and 10μΜ DPI, a NADPH oxidase inhibitor. According to the results, 350mL of 2mgL(-1) DCF showed higher degradation (>50%) under 167W electric power density and frequency at 862kHz for 120min, compared to degradation in all other cases, followed by a significant elimination of its toxicity. Specifically, US DCF-treated hemocytes showed a significant attenuation of DCF-mediated cytotoxic, oxidative and genotoxic effects, which appeared to be caused by NADPH oxidase and NO synthase activation, since their inhibition was followed by a significant elimination of (.)O2(-) and NO2(-) generation and the concomitant oxidative damage within cells. The results of the present study showed for the first time that unspecific mode of action of DCF, associated with the induction of NADPH oxidase

  3. A taxonomic synopsis of Altingiaceae with nine new combinations.

    Science.gov (United States)

    Ickert-Bond, Stefanie M; Wen, Jun

    2013-01-01

    A taxonomic synopsis of the Altingiaceae is presented, including the taxonomic enumeration and distribution of 15 recognized species based on studies of 1,500 specimens from 24 herbaria throughout the distributional range of the taxa. Previous phylogenetic analyses based on several molecular markers have shown that Altingia and Semiliquidambar are nested within Liquidambar. All Altingia and Semiliquidambar species are now formally transferred to Liquidambar, which has the nomenclatural priority. The following nine new combinations are herein made: Liquidambar cambodiana(Lecomte) Ickert-Bond & J. Wen, Liquidambar caudata (H. T. Chang) Ickert-Bond & J. Wen, Liquidambar chingii (Metcalf) Ickert-Bond & J. Wen, Liquidambar gracilipes (Hemsl.) Ickert-Bond & J. Wen, Liquidambar multinervis(Cheng) Ickert-Bond & J. Wen, Liquidambar obovata (Merrill & Chun) Ickert-Bond & J. Wen, Liquidambar poilanei (Tardieu) Ickert-Bond & J. Wen, Liquidambar siamensis (Craib) Ickert-Bond & J. Wen, and Liquidambar yunnanensis (Rehder & Wilson) Ickert-Bond & J. Wen.

  4. A taxonomic synopsis of Altingiaceae with nine new combinations

    Directory of Open Access Journals (Sweden)

    Stefanie Ickert-Bond

    2013-12-01

    Full Text Available A taxonomic synopsis of the Altingiaceae is presented, including the taxonomic enumeration and distribution of 15 recognized species based on studies of 1,500 specimens from 24 herbaria throughout the distributional range of the taxa. Previous phylogenetic analyses based on several molecular markers have shown that Altingia and Semiliquidambar are nested within Liquidambar. All Altingia and Semiliquidambar species are now formally transferred to Liquidambar, which has the nomenclatural priority. The following nine new combinations are herein made: Liquidambar cambodiana (Lecomte Ickert-Bond & J. Wen, L. caudata (H. T. Chang Ickert-Bond & J. Wen, L. chingii (Metcalf Ickert-Bond & J. Wen, L. gracilipes (Hemsl. Ickert-Bond & J. Wen, L. multinervis (Cheng Ickert-Bond & J. Wen, L. obovata (Merrill & Chun Ickert-Bond & J. Wen, L. poilanei (Tardieu Ickert-Bond & J. Wen, L. siamensis (Craib Ickert-Bond & J. Wen, and L. yunnanensis (Rehder & Wilson Ickert-Bond & J. Wen.

  5. Taxonomic Studies on the Genus Arnebia Forssk. (Boraginaceae in India

    Directory of Open Access Journals (Sweden)

    Kumar Ambrish

    2014-12-01

    Full Text Available The genus Arnebia Forssk. in India is taxonomically studied based on field surveys, collection of live plants, consultation of herbarium and literature. The genus is represented in India by 10 taxa including 8 species and 2 varieties viz., Arnebia bhattacharyyae K. Ambrish & S.K. Srivast., A. benthamii (Wall. ex G. Don I.M. Johnst., A. euchroma ( Royle I.M. Johnst., A. guttata Bunge, A. hispidissima (Sieber ex Lehm. A.DC., A. linearifolia A.DC., A. griffithii Boiss., A. nandadeviensis K. Chandra Sek. & R.S. Rawal , A. euchroma var. grandis (Bornm. Kazmi and A. guttata var. thomsonii (C.B. Clarke Kazmi, distributed in Jammu & Kashmir, Himachal Pradesh and Uttarakhand in North-West Himalaya to Uttar Pradesh, Punjab and Rajasthan in India. Dichotomous keys to all the species in India along with taxonomic description, distribution, illustrations and images of most of the species including type and their economic importance are provided.

  6. Taxonomic names, metadata, and the Semantic Web

    Directory of Open Access Journals (Sweden)

    Roderic D. M. Page

    2006-01-01

    Full Text Available Life Science Identifiers (LSIDs offer an attractive solution to the problem of globally unique identifiers for digital objects in biology. However, I suggest that in the context of taxonomic names, the most compelling benefit of adopting these identifiers comes from the metadata associated with each LSID. By using existing vocabularies wherever possible, and using a simple vocabulary for taxonomy-specific concepts we can quickly capture the essential information about a taxonomic name in the Resource Description Framework (RDF format. This opens up the prospect of using technologies developed for the Semantic Web to add ``taxonomic intelligence" to biodiversity databases. This essay explores some of these ideas in the context of providing a taxonomic framework for the phylogenetic database TreeBASE.

  7. Taxonomical problems of family Tricholomataceae (Agaricales

    Directory of Open Access Journals (Sweden)

    Halina Komorowska

    2014-08-01

    Full Text Available On the ground of the latest approachable literature the taxonomical and nomenclatural problems of family Tricholomataceae and same critical genus such as: Arrhenia, Armillaria, Clitocybe, Lepista, Gloiocephala, Hemimycena, Helotium, Mycena, Laccaria, Oudemansiella, Xirula, Xeromphalia (Xeromphalina was introduced.

  8. A taxonomic revision of Lamium (Lamiaceae)

    OpenAIRE

    Mennema, J.

    1989-01-01

    The present study deals with the systematics and taxonomy of the genus Lamium (Lamiaceae). The taxonomic revision is mainly based on the study of herbarium collections, and to a smaller degree on field observations and abstracts from literature. The research was done at the Rijksherbarium, Leyden, while many other Herbaria were shortly visited. As the genus Lamium was never before monographed, a short survey is given of the taxonomic history of Lamium, which goes back as far as Linnaeus (1753...

  9. Wing-Pigments of Butterflies as Reviewed from the Systematic and Taxonomic Points of View

    OpenAIRE

    梅鉢, 幸重; Yoshishige, UMEBACHI; 金沢大学理学部生物学教室; Department of Biology, Faculty of Science, Kanazawa University

    1988-01-01

    Wing-pigments of butterflies are reviewed especially from the standpoint of distribution. The pigments include pteridine pigments, ommochromes, papiliochromes, tetrapyrrolic pigments, flavonoids, and others. Chemistry and biochemistry of these pigments are briefly described, and their distributions are described in detail, especially in the Pieridae, Papilionidae, Nymphalidae, and Satyridae. Interestingly, some pigments are characteristic of some taxonomic groups such as family, subsfamily, a...

  10. Converting Taxonomic Descriptions to New Digital Formats

    Directory of Open Access Journals (Sweden)

    Hong Cui

    2008-01-01

    Full Text Available Abstract.--The majority of taxonomic descriptions is currently in print format. The majority of digital descriptions are in formats such as DOC, HTML, or PDF and for human readers. These formats do not convey rich semantics in taxonomic descriptions for computer-aided process. Newer digital formats such as XML and RDF accommodate semantic annotations that allow computers to process the rich semantics on human's behalf, thus open up opportunities for a wide range of innovative usages of taxonomic descriptions, such as searching in more precise and flexible ways, integrating with gnomic and geographic information, generating taxonomic keys automatically, and text data mining and information visualization etc. This paper discusses the challenges in automated conversion of multiple collections of descriptions to XML format and reports an automated system, MARTT. MARTT is a machine-learning system that makes use of training examples to tag new descriptions into XML format. A number of utilities are implemented as solutions to the challenges. The utilities are used to reduce the effort for training example preparation, to facilitate the creation of a comprehensive schema, and to predict system performance on a new collection of descriptions. The system has been tested with several plant and alga taxonomic publications including Flora of China and Flora of North America.

  11. Taxonomic turnover and abundance in Cretaceous to Tertiary wood floras of Antarctica: implications for changes in forest ecology

    NARCIS (Netherlands)

    Cantrill, David J.; Poole, I.J.

    2004-01-01

    Based on the temporal distribution, abundance, and taxonomic composition of wood floras, four phases of vegetation development are recognized through the Cretaceous to Early Tertiary of the Antarctic Peninsula: (1) Aptian to Albian communities dominated by podocarpaceous, araucarian, and minor

  12. Taxonomic status of Anastrepha fraterculus

    International Nuclear Information System (INIS)

    Steck, G.J.

    1999-01-01

    There has long been speculation that nominal Anastrepha fraterculus comprises more than a single biological species. Herein is a review of data supporting the hypothesis that multiple cryptic species are present. Evidence includes unusual variation in pest status, morphology, karyotypes, isozymes, mitochondrial DNA and cuticular hydrocarbon. The data strongly support the notion of multiple cryptic species. However, it is not yet possible to state how many species may be involved or to delineate them by diagnostic morphology, distribution, host plants or behavior. A combination of methodologies will be needed to resolve the complex. (author)

  13. A taxonomic revision of Lamium (Lamiaceae)

    NARCIS (Netherlands)

    Mennema, J.

    1989-01-01

    The present study deals with the systematics and taxonomy of the genus Lamium (Lamiaceae). The taxonomic revision is mainly based on the study of herbarium collections, and to a smaller degree on field observations and abstracts from literature. The research was done at the Rijksherbarium, Leyden,

  14. Polyphasic taxonomic characterization of lactic acid bacteria ...

    African Journals Online (AJOL)

    Polyphasic taxonomic characterization of lactic acid bacteria isolated from spontaneous sorghum fermentations used to produce ting, a traditional South African food. ... The results of these analyses showed that ting fermentation involved at least three different species of LAB, i.e. Lactobacillus fermentum, L. plantarum

  15. A taxonomic revision of Plagiogyriaceae (Pteridophyta)

    NARCIS (Netherlands)

    Zhang, Xian-Chun; Nooteboom, H.P.

    1998-01-01

    A taxonomic revision of Plagiogyriaceae is presented. One genus and 11 species are recognised. One species, P. egenolfioides, is subdivided into four varieties. Only one species, P. pectinata, occurs in the New World, all others in the Old World. One species, P. glauca, and one variety, P.

  16. Taxonomía y distribución del género Leptoscelis en Costa Rica (Hemiptera: Heteroptera: Coreidae: Leptoscelini Taxonomy and distribution of the genus Leptoscelis in Costa Rica (Hemiptera: Heteroptera: Coreidae: Leptoscelini

    Directory of Open Access Journals (Sweden)

    Harry Brailovsky

    2012-03-01

    Full Text Available Se revisa el género Leptoscelis Laporte (Coreidae: Leptoscelini para Costa Rica y se describe una especie nueva, L. conspicuus. Se discuten sus relaciones con L. quadrisignatus (Distant y L. tricolor Westwood. Leptoscelis bisbimaculata Breddin es sinonimizada con L. quadrisignatus. Se cita por primera vez L. tricolor para Costa Rica. El trabajo incluye nuevos datos de distribución para el género, ilustraciones de las especies y de los parámeros y una clave para la identificación de las especies costarricenses.The genus Leptoscelis Laporte (Coreidae: Leptoscelini from Costa Rica is revised. One new species, L. conspicuus, is described and compared with L. quadrisignatus (Distant and L. tricolor Westwood. Leptoscelis bisbimaculata Breddin is synonymized with L. quadrisignatus. Leptoscelis tricolor is recorded for the first time from Costa Rica. New distribution records are presented. Habitus illustrations and drawings of parameres are provided. A key to the known Costarican species is presented.

  17. Taxonomic Studies on Thai Anthocerotophyta I. The Genera Dendroceros and Megaceros (Dendrocerotaceae

    Directory of Open Access Journals (Sweden)

    Sahut Chantanaorrapint

    2014-12-01

    Full Text Available A taxonomic review of the hornwort genera Dendroceros Nees and Megaceros Campb. in Thailand is presented, based on herbarium specimens and field surveys. Three species are recognized, namely D. cucullatus Steph., D. suplanus Steph. and M. flagellaris (Mitt. Steph. A key, descriptions and line drawings and notes on the ecology and geographical distribution of the species are provided.

  18. Chrysomya albiceps and C. rufifacies (Diptera: Calliphoridae): contribution to an ongoing taxonomic problem.

    Science.gov (United States)

    Tantawi, T I; Greenberg, B

    1993-05-01

    Until recently, the two biologically equivalent blow flies Chrysomya albiceps (Wiedemann) and Chrysomya rufifacies (Macquart) had disjunct distributions outside the Americas; the former was Palaearctic, the latter Australasian and Oriental. The two species are now spreading throughout the Americas and coexist in Argentina. The predatory "hairy" larvae of both species are difficult to separate, which could result in taxonomic errors. New diagnostic characters are presented to differentiate the third instars of the two species. The usefulness of the prostigmatic bristle as a diagnostic taxonomic character in distinguishing adults of these species is questioned.

  19. Taxonomic, spatial and adaptive genetic variation of Beta section Beta.

    Science.gov (United States)

    Andrello, Marco; Henry, Karine; Devaux, Pierre; Desprez, Bruno; Manel, Stéphanie

    2016-02-01

    The genetic variation of Beta section Beta is structured into four taxonomic and spatial clusters. There are significant associations between molecular markers and environmental variables. We investigated the genetic diversity of Beta section Beta, which includes the wild and cultivated relatives of the sugar beet. The taxa included in the study were: Beta vulgaris subsp. maritima, B. vulgaris subsp. adanensis, B. macrocarpa, B. patula and B. vulgaris subsp. vulgaris (garden beet, leaf beet and swiss chards). We collected 1264 accessions originating from the entire distribution area of these taxa and genotyped them for 4436 DArT markers (DArTs). We showed that the genetic variation of these accessions is structured into four taxonomic and spatial clusters: (1) samples of Beta macrocarpa, (2) samples of Beta vulgaris subsp. adanensis, (3) Mediterranean and Asian samples and (4) Atlantic and Northern European samples. These last two clusters were mainly composed of samples of Beta vulgaris subsp. maritima. We investigated in deeper detail the genetic structure of B. vulgaris subsp. maritima, which constituted the majority (80%) of the wild samples. This subspecies exhibited a clinal genetic variation from South-East to North-West. We detected some markers significantly associated to environmental variables in B. vulgaris subsp. maritima. These associations are interpreted as results of natural selection. The variable most often involved in the associations was annual mean temperature. Therefore, these markers can be useful for the development of frost-tolerant winter beets and drought-tolerant rain-fed beets.

  20. Phylogenetic analysis and taxonomic revision of Physodactylinae (Coleoptera, Elateridae

    Directory of Open Access Journals (Sweden)

    Simone Policena Rosa

    2014-01-01

    Full Text Available A phylogeny based on male morphological characters and taxonomic revision of the Physodactylinae genera are presented. The phylogenetic analysis based on 66 male characters resulted in the polyphyly of Physodactylinae which comprises four independent lineages. Oligostethius and Idiotropia from Africa were found to be sister groups. Teslasena from Brazil was corroborated as belonging to Cardiophorinae clade. The South American genera Physodactylus and Dactylophysus were found to be sister groups and phylogenetically related to Heterocrepidius species. The Oriental Toxognathus resulted as sister group of that clade plus (Dicrepidius ramicornis (Lissomus sp, Physorhynus erythrocephalus. Taxonomic revisions include diagnoses and redescriptions of genera and distributional records and illustrations of species. Key to species of Teslasena, Toxognathus, Dactylophysus and Physodactylus are also provided. Teslasena lucasi is synonymized with T. femoralis. A new species of Dactylophysus is described, D. hirtus sp. nov., and lectotypes are designated to non-conspecific D. mendax sensu Fleutiaux and Heterocrepidius mendax Candèze. Physodactylus niger is removed from synonymy under P. oberthuri; P. carreti is synonymized with P. niger; P. obesus and P. testaceus are synonymized with P. sulcatus. Nine new species are described in Physodactylus: P. asper sp. nov., P. brunneus sp. nov., P. chassaini sp. nov., P. flavifrons sp. nov., P. girardi sp. nov., P. gounellei sp. nov., P. latithorax sp. nov., P. patens sp. nov. and P. tuberculatus sp. nov.

  1. Eco-taxonomic distribution of plant species around motor mechanic ...

    African Journals Online (AJOL)

    A survey of plant species and their families present in auto mechanic workshops in Benin City and Asaba was carried out. The frequency of occurrence of plants in the sites visited was used to determine prevalence. Peperomia pellucida occurred most in all the sites visited with a 55% frequency. The high rate of occurrence ...

  2. Dung Beetles along a Tropical Altitudinal Gradient: Environmental Filtering on Taxonomic and Functional Diversity.

    Science.gov (United States)

    Nunes, Cássio Alencar; Braga, Rodrigo Fagundes; Figueira, José Eugênio Cortes; Neves, Frederico de Siqueira; Fernandes, G Wilson

    2016-01-01

    Mountains provide an interesting context in which to study the many facets of biodiversity in response to macroclimate, since environmental conditions change rapidly due to elevation. Although the decrease in biodiversity with increasing elevation is generally accepted, our understanding of the variation of functional diversity along altitudinal gradients is still poorly known. The partitioning of diversity into spatial components can help to understand the processes that influence the distribution of species, and these studies are urgently needed in face of the increasing threats to mountain environments throughout the world. We describe the distribution of dung beetle diversity along an altitudinal gradient on a tropical mountain in southeastern Brazil, including the spatial partitioning of taxonomic and functional diversities. The altitudinal gradient ranged from 800 up to 1400 m a.s.l. and we collected dung beetles at every 100 m of altitude. We used the Rao Index to calculate γ, α and β diversity for taxonomic and functional diversity of dung beetles. Climatic, soil and vegetation variables were used to explain variation in community attributes along the altitudinal gradient. Dung beetle richness declined with altitude and was related to climatic and vegetation variables, but functional diversity did not follow the same pattern. Over 50% of γ taxonomic diversity was caused by among altitudes diversity (β), while almost 100% of functional diversity was due to the α component. Contrasting β taxonomic with β functional diversity, we suggest that there is ecological redundancy among communities and that the environment is filtering species in terms of the Grinnellian niche, rather than the Eltonian niche. β taxonomic diversity is caused mainly by the turnover component, reinforcing the hypothesis of environmental filtering. Global warming may have strong effects on mountain communities due to upslope range shifts and extinctions, and these events will

  3. Colombian coca plants. A critical discussion on taxonomic aspects of cultivated Erythroxylum species (Erythroxylaceae)

    International Nuclear Information System (INIS)

    Galindo Bonilla, Aida; Fernandez Alonzo, Jose Luis

    2010-01-01

    Forensic botany is in high demand in Colombia in connection with plant material, mainly coca from illicit crops. The taxonomic study of the two species and four varieties of Erythroxylum P. Browne (Erythroxylaceae) cultivated in Colombia was carried out. Hybridization between E. coca and E. novogranatense and between the two varieties of E. coca is suggested, and important changes in the geographic distribution of all taxa are described. Both, hybridization and changes in distribution patterns are due to anthropic intervention.

  4. Extrafloral nectaries in Combretaceae: morphology, anatomy and taxonomic significance

    Directory of Open Access Journals (Sweden)

    P. M. Tilney

    2004-09-01

    Full Text Available Extrafloral nectaries (EFNs in members of the Combretaceae are nectaries not involved with pollination and occurring on vegetative structures; they are believed to attract ants to protect plants against herbivorv by other insects. In the Combretaceae EFNs are reported in species of Terminalia L. and Pteleopsis Engl., putative EFNs in Meiostemon Exell & Stace and Quisqualis L., and an absence of EFNs in Combretum Loefl. and Lumnitzera Willd. EFNs in the family are generally spherical in shape and may be raised, level with the surface or somewhat concave. They are similar in the Terminalia and  Pteleopsis species where they display varying degrees of internal zonation and are composed of small cells; those species observed in the field were all found to have functional EFNs. In Meiostemon tetrandrum (Exell Exell & Stace, Quisqualis indica L.. Q. littorea (Engl. Exell and Q. paviflora Gerrard ex Sond.. apparent EFNs lack internal zonation and are composed of enlarged cells; confirmation is required as to whether these are functional . The formation of EFNs appears to be highly flexible. They are usually essentially associated with new growth but their occurrence is sporadic and they do not appear on every leaf or every' branch of a plant. The distribution of EFNs on leaves, when present, is of taxonomic significance to separate species of Pteleopsis and Terminalia: otherwise the presence or absence and distribution of EFNs are too variable and sporadic in occurrence to be of taxonomic significance at the species level. Indiscriminate use of the terms gland and domatium instead of EFN. and possible confusion with damage caused by other organisms, has probably con­tributed to many of these structures not previously being recorded as EFNs. Floral and extrafloral nectar samples of T. phanerophlebia Engl. & Diels differed in sugar composition.

  5. Taxonomic studies on Indian Pseudolepicoleaceae (Marchantiophyta: Jungermanniales

    Directory of Open Access Journals (Sweden)

    Devendra Singh

    2014-03-01

    Full Text Available The Indian taxa of family Pseudolepicoleaceae Fulford & J.Taylor are morpho-taxonomically investigated and four species, viz. Blepharostoma trichophyllum (L. Dumort., Pseudolepicolea fryei (Perss. Grolle & Ando, Pseudolepicolea trollii (Herzog Grolle & Ando and Temnoma setigerum (Lindenb. R.M.Schust. have been recognized in the bryoflora of the country. Pseudolepicolea fryei, a species so far known from Russia and North America, is reported here for the first time from India. Whereas, P. trollii subsp. andoi (R.M.Schust. S.Hatt. & Mizut. and P. trolli var. darjeelingensis S.Hatt. & Mizut., earlier recorded from the country, have not been found morphologically distinct from the typical taxon.

  6. Taxonomic novelties within the genus Columnea (Gesneriaceae)

    International Nuclear Information System (INIS)

    Amaya Marquez, Marisol

    2010-01-01

    A new species of Columnea and a new variety of Columnea lanata (Seem.) Kuntze belonging to section Collandra (Gesneriaceae) are described and illustrated. The new species was found in the Pacific slopes of the Cordillera Occidental in the Department of Choco in Colombia; the new variety comes from the Pacific slopes of the Cordillera Occidental, in the region of Murri located at the North West of the Department of Antioquia . A taxonomic key to distinguish the new species from the morphologically closer species is presented.

  7. Lactobacillus species: taxonomic complexity and controversial susceptibilities.

    Science.gov (United States)

    Goldstein, Ellie J C; Tyrrell, Kerin L; Citron, Diane M

    2015-05-15

    The genus Lactobacillus is a taxonomically complex and is composed of over 170 species that cannot be easily differentiated phenotypically and often require molecular identification. Although they are part of the normal human gastrointestinal and vaginal flora, they can also be occasional human pathogens. They are extensively used in a variety of commercial products including probiotics. Their antimicrobial susceptibilities are poorly defined in part because of their taxonomic complexity and are compounded by the different methods recommended by Clinical Laboratory Standards Institute and International Dairy Foundation. Their use as probiotics for prevention of Clostridium difficile infection is prevalent among consumers worldwide but raises the question of will the use of any concurrent antibiotic effect their ability to survive. Lactobacillus species are generally acid resistant and are able to survive ingestion. They are generally resistant to metronidazole, aminoglycosides and ciprofloxacin with L. acidophilus being susceptible to penicillin and vancomycin, whereas L. rhamnosus and L. casei are resistant to metronidazole and vancomycin. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. TaxMan: a taxonomic database manager

    Directory of Open Access Journals (Sweden)

    Blaxter Mark

    2006-12-01

    Full Text Available Abstract Background Phylogenetic analysis of large, multiple-gene datasets, assembled from public sequence databases, is rapidly becoming a popular way to approach difficult phylogenetic problems. Supermatrices (concatenated multiple sequence alignments of multiple genes can yield more phylogenetic signal than individual genes. However, manually assembling such datasets for a large taxonomic group is time-consuming and error-prone. Additionally, sequence curation, alignment and assessment of the results of phylogenetic analysis are made particularly difficult by the potential for a given gene in a given species to be unrepresented, or to be represented by multiple or partial sequences. We have developed a software package, TaxMan, that largely automates the processes of sequence acquisition, consensus building, alignment and taxon selection to facilitate this type of phylogenetic study. Results TaxMan uses freely available tools to allow rapid assembly, storage and analysis of large, aligned DNA and protein sequence datasets for user-defined sets of species and genes. The user provides GenBank format files and a list of gene names and synonyms for the loci to analyse. Sequences are extracted from the GenBank files on the basis of annotation and sequence similarity. Consensus sequences are built automatically. Alignment is carried out (where possible, at the protein level and aligned sequences are stored in a database. TaxMan can automatically determine the best subset of taxa to examine phylogeny at a given taxonomic level. By using the stored aligned sequences, large concatenated multiple sequence alignments can be generated rapidly for a subset and output in analysis-ready file formats. Trees resulting from phylogenetic analysis can be stored and compared with a reference taxonomy. Conclusion TaxMan allows rapid automated assembly of a multigene datasets of aligned sequences for large taxonomic groups. By extracting sequences on the basis of

  9. Advances in the mode of action of pyrethroids.

    Science.gov (United States)

    Clark, J Marshall; Symington, Steven B

    2012-01-01

    The ability to clone, express, and electrophysiologically measure currents carried by voltage-gated ion channels has allowed a detailed assessment of the action of pyrethroids on various target proteins.Recently, the heterologous expression of various rat brain voltage-gated sodium channel isoforms in Xenopus laevis oocytes has determined a wide range of sensitivities to the pyrethroids, with some channels virtually insensitive and others highly sensitive. Furthermore, some isoforms show selective sensitivity to certain pyrethroids and this selectivity can be altered in a state-dependent manner. Additionally, some rat brain isoforms are apparently more sensitive to pyrethroids than the corresponding human isoform. These finding may have significant relevance in judging the merit and value of assessing the risk of pyrethroid exposures to humans using toxicological studies done in rat.Other target sites for certain pyrethroids include the voltage-gated calcium and chloride channels. Of particular interest is the increased effect of Type II pyrethroids on certain phosphoforms of the N-type Ca(v)2.2 calcium channel following post-translational modification and its relationship to enhanced neurotransmitter release seen in vivo.Lastly, parallel neurobehavioral and mechanistic studies on three target sites suggest that a fundamental difference exists between the action of Types I and II pyrethroids, both on a functional and molecular level. These differences should be considered in any future risk evaluation of the pyrethroids.

  10. Neurotoxicological effects and the mode of action of pyrethroid insecticides

    NARCIS (Netherlands)

    Vijverberg, H.P.M.; Bercken, Joep van den

    1990-01-01

    Neuroexcitatory symptoms of acute poisoning of vertebrates by pyrethroids are related to the ability of these insecticides to modify electrical activity in various parts of the nervous system. Repetitive nerve activity, particularly in the sensory nervous system, membrane depolarization, and

  11. Furocoumarins, biophysical investigations on their modes of action

    International Nuclear Information System (INIS)

    Kittler, L.; Loeber, G.

    1983-01-01

    Investigation of the combined effect of furocoumarins and ultraviolet light of 365 nm wavelength (UV light) on cellular constituents are important for they have clearly increased the knowledge on basic processes involved in PUVA therapy. Studies of the action on nucleic acids both in isolated state and in situ led to the following conclusions, when 8-methoxypsoralen (8-MOP) and angelicin were used as sensitizers: Crosslinking between the drug and the nucleic acid bases is preferred in A-T rich or A-U rich sites with the nucleic acid being in B conformation. In situ crosslinked DNA does not influence the adsorption of phage lambda on the surface of E. coli. There are probably three types of furocoumarins mediated crosslinks inside the phage: Type I, corresponding to crosslinking between complementary strands of the DNA duplex, type II, corresponding to crosslinks between adjacent sites in the folded DNA structure (hair pin crosslinks) and DNA protein crosslinks. Type I does not prevent the DNA from getting into the host cell, while the two latter do. PUVA treatment of human lymphocyte cultures is manifested by chromosomal aberrations such as premature centromere division and major coiling. However, treatment with 8-MOP or UV light alone do produce the same kind of aberrations. Under the action of UV light, 8-MOP or trimethylpsoralen become covalently bound to unsaturated fatty acids. The photoreaction preceeds without essential contribution of singlet oxygen and hydroperoxides. (author)

  12. Vasodilatation with pinacidil. Mode of action in rat resistance vessels

    International Nuclear Information System (INIS)

    Videbaek, L.M.; Aalkjaer, C.; Mulvany, M.J.

    1988-01-01

    Pinacidil is a newly developed antihypertensive vasodilator, proposed to belong to the new group of smooth muscle relaxants, the K+ channel openers. The in vitro effects of pinacidil on induced tone, smooth muscle membrane potential and 86 Rb and 42 K efflux from rat resistance vessels (internal diameter about 200 microns) were studied. Tone induced with noradrenaline was concentration-dependently inhibited by pinacidil. Responses to electrical field stimulation were also inhibited. However, tone induced with high K+ depolarization, noradrenaline in the presence of high K+, caffeine-induced contractions and noradrenaline contractions in the presence of felodipine were little affected by pinacidil. Pinacidil caused concentration-dependent hyperpolarisation of the resting smooth muscle. Pinacidil caused only a small and transient increase of the 86 Rb efflux rate constant, while the same concentrations of pinacidil produced a significant increase in the 42 K efflux rate constant. Our results seem to indicate that the relaxant effect of pinacidil is the result of an increase in K+ permeability, thus causing hyperpolarisation and relaxation. The opened K+ channels appear to be selective for K+ over Rb+

  13. [Mode of action of microbial anti-MRSA agents].

    Science.gov (United States)

    Tomoda, Hiroshi

    2012-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is known as a major nosocomial pathogen that has also developed resistance to many antibiotics. Moreover, MRSA resistance to a last-resort antibiotic, vancomycin, has been reported. Therefore, new anti-infectious agents to prevent and treat MRSA infection are needed. Based on this background, our group has focused on the discovery of new microbial agents active against MRSA infection. Viridicatumtoxin and spirohexaline, produced by Penicillium sp. FKI-3368, were isolated as inhibitors of undecaprenyl pyrophosphate (UPP) synthase of Staphylococcus aureus, which was involved in cell wall synthesis. Viridicatumtoxin and spirohexaline with a pentacyclic spiro skeleton inhibited UPP synthase activity with an IC(50) value of 4.0 and 9.0 µM, respectively. Actually, the growth of gram-positive bacteria including MRSA was strongly inhibited by the compounds. Our computational modeling experiments indicated that spirohexaline A was inserted into the substrate pocket of UPP synthase and interacted with Glu(88) via a carbamoyl group of the compound, with Ala(76), Met(54) and Asn(35) via three hydroxyl groups, and with certain hydrophobic amino acids via a spiro ring. Cyslabdan, produced by Streptomyces sp. K04-0144, was isolated as a potentiator of β-lactam imipenem activity against MRSA. The compound consisted of a labdan skeleton and an N-acetylcysteine. Cyslabdan potentiated imipenem activity by over 1000 fold, drastically reducing the MIC value of imipenem against MRSA from 16 to 0.03 µg/mL. The binding proteins of cyslabdan were investigated in the lysate of MRSA to identify FemA, which was involved in the formation of the pentaglycine interpeptide bridge in MRSA peptidoglycan.

  14. Mode of Action and Synergy of Ceftazidime and Baicalein against ...

    African Journals Online (AJOL)

    Purpose: To investigate the antibacterial activity of baicalein used alone, or in combination with ceftazidime, against Streptococcus pyogenes. ... Results: The MIC of ceftazidime and baicalein against all the S. pyogenes strains were 0.50 and >. 256.0 µg/ml, respectively. .... shaking water bath for 4 h. The cell pellets were.

  15. Peptide antibiotics: discovery, modes of action, and applications

    National Research Council Canada - National Science Library

    Dutton, Christopher J

    2002-01-01

    ... and the application of biotechnology to many aspects of their development. While the origins of the peptides covered in this book are diverse, common themes can be readily identified. Peptides originally found in frogs and insects are now produced by bacterial fermentation, and site-directed mutagenesis has been brought to bear to produce novel ...

  16. Biostimulation of grapevine : mode of action and possible agronomic uses

    OpenAIRE

    Krzyzaniak, Yuko; Trouvelot, Sophie; Heloir, Marie-Claire; Fourquez, P.; Magnin-Robert, Jean-Bernard; Randoux, B.; Siah, A.; Halama, Patrice; Moreau, Emmanuelle; Adrian, Marielle

    2016-01-01

    Although there is a growing interest for the use of biostimulants in agriculture, only few methods allowing a precise description of their effects on plants have been reported. In the IRIS+ FUI project, two major and highly different worldwide crops, wheat (annual, monocotyledon) and grapevine (perennial, broadleaf), were chosen to deepen our knowledge of such compounds and explore their potential additional interest. The first objective is to develop in greenhouse conditions, a panel of tool...

  17. Mini Review: Mode of Action of Mosquito Repellents

    Science.gov (United States)

    2013-01-01

    Mosquitoes vector numerous diseases including malaria , den- gue, west nile virus and yellow fever. Even in the absence of disease, mosquitoes are an...labellum of the fly responded to both DEET and other bitter feeding deterrents such as quinine . These ef- fects were determined to be mediated by direct...activated by sucrose (Fig. 3D), while the smallest amplitude action potential was activated by the feeding deterrent, quinine (Fig. 3E). This neuron with

  18. Mode of Action and Synergy of Ceftazidime and Baicalein against ...

    African Journals Online (AJOL)

    Cytoplasmic membrane (CM) permeability technique, enzyme assays, transmission electron microscopy and Fourier transforminfrared microspectroscopy were used to investigate the changes in the bacterial biomolecules. Results: The MIC of ceftazidime and baicalein against all the S. pyogenes strains were 0.50 and ...

  19. Ecdysone Agonist: New Insecticides with Novel Mode of Action

    Directory of Open Access Journals (Sweden)

    Y. Andi Trisyono

    2002-12-01

    Full Text Available Development of insect resistance to insecticide has been the major driving force for the development of new insecticides. Awareness and demand from public for more environmentally friendly insecticides have contributed in shifting the trend from using broad spectrum to selective insecticides. As a result, scientists have looked for new target sites beyond the nervous system. Insect growth regulators (IGRs are more selective insecticides than conventional insecticides, and ecdysone agonists are the newest IGRs being commercialized, e.g. tebufenozide, methoxyfenozide, and halofenozide. Ecdysone agonists bind to the ecdysteroid receptors, and they act similarly to the molting hormone 20-hydroxyecdysone. The binding provides larvae or nymphs with a signal to enter a premature and lethal molting cycle. In addition, the ecdysone agonists cause a reduction in the number of eggs laid by female insects. The ecdysone agonists are being developed as selective biorational insecticides. Tebufenozide and methoxyfenozide are used to control lepidopteran insect pests, whereas halofenozide is being used to control coleopteran insect pests. Their selectivity is due to differences in the binding affinity between these compounds to the receptors in insects from different orders. The selectivity of these compounds makes them candidates to be used in combinations with other control strategies to develop integrated pest management programs in agricultural ecosystems. Key words: new insecticides, selectivity, ecdysone agonists

  20. Mode of action of new organic ammonium salts

    International Nuclear Information System (INIS)

    Miko, M.; Gulasova, A.; Devinsky, F.

    1998-01-01

    The aim of this paper was primary biochemical screening of cytotoxic activity. The measure of the cytotoxic effect was the degree of inhibition of 14 C-adenine and 14 C-valine incorporation into TCA-insoluble fraction of Ehrlich ascites carcinoma (EAC) cells. The primary biochemical screening was carried out with the 12 new organic ammonium salts (OAS), from a homologous series of N-alkyl-(N 2 -dodekanoylethyl)-dimethylammonium bromide. In a first approach to determine the model of action of the cytotoxic active compounds, the kinetics of DNA, RNA and protein synthesis inhibition were examined using isotope incorporation. On the basis of primary screening, one of the most active compounds, namely N-octyl-N 2 -dodekanoylethyl)-dimethylammonium bromide was chosen for further biochemical studies. Selected OAS inhibited biosynthesis of nucleic acids indicated by incorporation of 14 C-adenine and biosynthesis of protein indicated by incorporation of 14 C-valine. From the results, it is obvious, that the biosynthesis of DNA, indicated by the incorporation of 14 -thymidine, was more sensitive than biosynthesis of RNA indicated by the incorporation of 14 C-uridine. OAS at the lower concentrations stimulated aerobic glycolysis of tumor cells. Such a stimulation of glycolysis at lower concentrations of OAS indicated a potential interference with respiratory processes in tumor cells, or in isolated mitochondria. We assumed that the cytotoxic effect of OAS could be consequence of cytolytic activity of OAS. (authors)

  1. Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol ...

    African Journals Online (AJOL)

    Purpose: To evaluate the antibacterial effect of ethanol extract of Mentha arvensis against multi-drug resistant Acinetobacter baumannii using liquid chromatography–mass spectrometry (LC-ESI-MS). Methods: Disc diffusion and microdilution assays were used to evaluate the antibacterial effect of the extract by measuring ...

  2. Mosquitocidal Activity and Mode of Action of the Isoxazoline Fluralaner

    Directory of Open Access Journals (Sweden)

    Shiyao Jiang

    2017-02-01

    Full Text Available Mosquitoes, such as Aedes aegypti and Anopheles gambiae, are important vectors of human diseases. Fluralaner, a recently introduced parasiticide, was evaluated as a mosquitocide in this study. On Ae. aegypti and An. gambiae fourth-instar larvae, fluralaner had 24-h LC50 (lethal concentration for 50% mortality values of 1.8 ppb and 0.4 ppb, respectively. Following topical application to adult Ae. aegypti, fluralaner toxicity reached a plateau in about 3 days, with 1- and 3-day LD50 (lethal dose for 50% mortality values of 1.3 ng/mg and 0.26 ng/mg, suggesting a slowly developing toxicity. Fipronil outperformed fluralaner by up to 100-fold in adult topical, glass contact, and feeding assays on Ae. aegypti. These data show that fluralaner does not have exceptional toxicity to mosquitoes in typical exposure paradigms. In electrophysiological recordings on Drosophila melanogaster larval central nervous system, the effectiveness of fluralaner for restoring nerve firing after gamma-aminobutyric acid (GABA treatment, a measure of GABA antagonism, was similar in susceptible Oregon-R and cyclodiene-resistant rdl-1675 strains, with EC50 (half maximal effective concentration values of 0.34 µM and 0.29 µM. Although this finding suggests low cross resistance in the presence of rdl, the moderate potency, low contact activity, and slow action of fluralaner argue against its use as an adult mosquitocide for vector control.

  3. Mosquitocidal Activity and Mode of Action of the Isoxazoline Fluralaner

    OpenAIRE

    Jiang, Shiyao; Tsikolia, Maia; Bernier, Ulrich R.; Bloomquist, Jeffrey R.

    2017-01-01

    Mosquitoes, such as Aedes aegypti and Anopheles gambiae, are important vectors of human diseases. Fluralaner, a recently introduced parasiticide, was evaluated as a mosquitocide in this study. On Ae. aegypti and An. gambiae fourth-instar larvae, fluralaner had 24-h LC50 (lethal concentration for 50% mortality) values of 1.8 ppb and 0.4 ppb, respectively. Following topical application to adult Ae. aegypti, fluralaner toxicity reached a plateau in about 3 days, with 1- and 3-day LD50 (lethal do...

  4. Mosquitocidal Activity and Mode of Action of the Isoxazoline Fluralaner.

    Science.gov (United States)

    Jiang, Shiyao; Tsikolia, Maia; Bernier, Ulrich R; Bloomquist, Jeffrey R

    2017-02-06

    Mosquitoes, such as Aedes aegypti and Anopheles gambiae , are important vectors of human diseases. Fluralaner, a recently introduced parasiticide, was evaluated as a mosquitocide in this study. On Ae. aegypti and An. gambiae fourth-instar larvae, fluralaner had 24-h LC 50 (lethal concentration for 50% mortality) values of 1.8 ppb and 0.4 ppb, respectively. Following topical application to adult Ae. aegypti , fluralaner toxicity reached a plateau in about 3 days, with 1- and 3-day LD 50 (lethal dose for 50% mortality) values of 1.3 ng/mg and 0.26 ng/mg, suggesting a slowly developing toxicity. Fipronil outperformed fluralaner by up to 100-fold in adult topical, glass contact, and feeding assays on Ae. aegypti . These data show that fluralaner does not have exceptional toxicity to mosquitoes in typical exposure paradigms. In electrophysiological recordings on Drosophila melanogaster larval central nervous system, the effectiveness of fluralaner for restoring nerve firing after gamma-aminobutyric acid (GABA) treatment, a measure of GABA antagonism, was similar in susceptible Oregon-R and cyclodiene-resistant rdl -1675 strains, with EC 50 (half maximal effective concentration) values of 0.34 µM and 0.29 µM. Although this finding suggests low cross resistance in the presence of rdl , the moderate potency, low contact activity, and slow action of fluralaner argue against its use as an adult mosquitocide for vector control.

  5. 4-Alkynylphenylsilatranes: Insecticidal activity, mammalian toxicity, and mode of action

    International Nuclear Information System (INIS)

    Horsham, M.A.; Palmer, C.J.; Cole, L.M.; Casida, J.E.

    1990-01-01

    4-Ethynyl- and 4-(prop-1-ynyl)phenylsilatranes [N(CH 2 CH 2 O) 3 SiR, R = C 6 H 4 -4-C triple-bond CH or C 6 H 4 -4-C triple-bond CCH 3 ] are highly toxic to houseflies (pretreated with piperonyl butoxide) and milkweed bugs (topical LD 50 s 3-14 μg/g) and to mice (intraperitoneal LD 50 s 0.4-0.9 mg/kg), and they are moderately potent inhibitors of the [ 35 S]-tert-butylbicyclophosphorothionate or TBPS binding site (GABA-gated chloride channel) of mouse brain membranes. Scatchard analysis indicates noncompetitive interaction of 4-ethynylphenylsilatrane with the TBPS binding site. Phenylsilatrane analogues with 4-substituents of H, CH 3 , Cl, Br, and C triple-bond CSi(CH 3 ) 3 are highly toxic to mice but have little or no activity in the insect and receptor assays. Radioligand binding studies with [4- 3 H]phenylsilatrane failed to reveal a specific binding site in mouse brain. Silatranes with R = H, CH 3 , CH 2 Cl, CH double-bond CH 2 , OCH 2 CH 3 , and C 6 H 4 -4-CH 2 CH 3 are of little or no activity in the insect and mouse toxicity and TBPS binding site assays as are the trithia and monocyclic analogues of phenylsilatrane. 4-Alkynylphenylsilatranes are new probes to examine the GABA receptor-ionophore complex of insects and mammals

  6. Digital food activism: Values, expertise and modes of action

    OpenAIRE

    Eli, Karin; Schneider, Tanja; Dolan, Catherine; Ulijaszek, Stanley

    2018-01-01

    New information and communication technologies (ICTs) increasingly enable social action and civic organisation, on both local and global scales. Ranging from social media platforms such as Facebook and Twitter, to mobile apps such as Buycott, and to data sharing wiki platforms and hacktivist projects, the activist landscape is rapidly shifting, collapsing geographic boundaries to form new issue publics and fast, sometimes mercurial, collective action. Within these emerging digital platforms f...

  7. Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol ...

    African Journals Online (AJOL)

    Reactive oxygen species (ROS) generation and protein leakage from the bacterial cells induced by the extract were also evaluated. .... Bacterial strain and culture media. A. baumannii strain ATCC 10545 was used in the current study. ... culture was then analyzed by SEM (Hitachi, Japan) at magnifications of 4,000 x.

  8. Germination inhibitors of fungal spores: identification and mode of action

    NARCIS (Netherlands)

    Chitarra, G.S.

    2003-01-01

    Fungi can be found in a wide variety of environments, such as seeds, plants, soil, water, insects, and food products. Fungi and their toxic metabolites cause losses of food products, and diseases in plants and animals, and may have adverse effects on human health. A crucial step in fungal

  9. [Modes of action of agrochemicals against plant pathogenic organisms].

    Science.gov (United States)

    Leroux, Pierre

    2003-01-01

    The chemical control of plant pathogens concerns mainly fungal diseases of crops. Most of the available fungicides act directly on essential fungal functions such as respiration, sterol biosynthesis or cell division. Consequently, these compounds can exhibit undesirable toxicological and environmental effects and sometimes select fungal resistant strains. Plant activators are expected to provide sustainable disease management in several crops because the development of resistance is not expected. Considering the future, the discovery of novel antifungal molecules will reap advantage from throughput screening methodologies and functional genomics.

  10. The mode of action of carbon tetrachloride on Fasciola hepatica

    Science.gov (United States)

    Khalidi, A.; Zaki, Saniha Amin

    1969-01-01

    1. A biliary fistula was prepared in twelve sheep. 2. Each animal was given 2 ml. of 14C-carbon tetrachloride (specific activity 15 mc/m-mole) and bile collected at 2, 4, 24 and 48 hr. 3. Specific activity was measured by liquid scintillation counting before and after each specimen had been heated to 75° C for 10 min to drive off volatile content (carbon tetrachloride). 4. Only traces of activity were present in the bile and heating did not alter this. 5. There was no difference in the survival times of adult Fasciola hepatica incubated in Hedon Flieg medium with and without 25% bile from non-medicated sheep, or with carbon tetrachloride in a concentration of 0·03%, but 25% of bile from sheep given 2 ml. of carbon tetrachloride 24 hr before greatly increased lethality in vitro. 6. The anthelmintic action of carbon tetrachloride on F. hepatica does not result from a direct action due to excretion in bile of unchanged carbon tetrachloride but of an unidentified toxic element not necessarily derived from the drug but which arises as a result of its administration. PMID:5815150

  11. Genetics, Biosynthesis, Structure, and Mode of Action of Lantibiotics

    Science.gov (United States)

    Kuipers, Anneke; Rink, Rick; Moll, Gert N.

    Lantibiotics are lanthionine-containing peptide antibiotics. They are characterized by having meso-lanthionine(s) and/or β-methyllanthionine(s) or both. These intramolecular monosulfide cross-links render the peptide resistant against breakdown by peptidases. Moreover, in several cases, the (methyl)lanthionines are essential for interaction with the so-called docking molecule lipid II. The best known lantibiotic, nisin, highly effectively inhibits growth of target cells via two mechanisms: (1) abduction of the cell wall precursor lipid II from the septum and (2) formation of pores composed of lipid II and nisin. (Methyl)lanthionines result from two enzyme-catalyzed posttranslational modifications: dehydration of serines/threonines and coupling of the resulting dehydro amino acids to cysteines. Besides the localization of the thioether bridges and dehydro amino acids in the lantibiotics, also the three-dimensional structure of some lantibiotics has been resolved by NMR. Genes encoding proteins involved in the biosynthesis of lantibiotics are present in clusters and may comprise combinations of the following genes in varying order: a structural gene that encodes a leader peptide and the lantibiotic propeptide, modification enzyme(s), a transporter responsible for the export of the lantibiotic and in some cases for cleavage of the leader peptide, a leader peptidase, a so-called immunity protein involved in self-protection of the host cell, components of a transporter also involved in self-protection, and two components of an autoinduction system.

  12. Modes of action of aspirin-like drugs.

    OpenAIRE

    Abramson, S; Korchak, H; Ludewig, R; Edelson, H; Haines, K; Levin, R I; Herman, R; Rider, L; Kimmel, S; Weissmann, G

    1985-01-01

    Current dogma holds that nonsteroidal anti-inflammatory drugs (NSAIDs) act by inhibition of the synthesis and release of prostaglandins. However, NSAIDs also inhibit the activation of neutrophils, which provoke inflammation by releasing products other than prostaglandins. We now report that NSAIDs (e.g., indomethacin, piroxicam) inhibit activation of neutrophils by inflammatory stimuli, such as C5-derived peptides and leukotriene B4, even when cyclooxygenase products generated in suspensions ...

  13. Artemisinin inhibits chloroplast electron transport activity: mode of action.

    Directory of Open Access Journals (Sweden)

    Adyasha Bharati

    Full Text Available Artemisinin, a secondary metabolite produced in Artemisia plant species, besides having antimalarial properties is also phytotoxic. Although, the phytotoxic activity of the compound has been long recognized, no information is available on the mechanism of action of the compound on photosynthetic activity of the plant. In this report, we have evaluated the effect of artemisinin on photoelectron transport activity of chloroplast thylakoid membrane. The inhibitory effect of the compound, under in vitro condition, was pronounced in loosely and fully coupled thylakoids; being strong in the former. The extent of inhibition was drastically reduced in the presence of uncouplers like ammonium chloride or gramicidin; a characteristic feature described for energy transfer inhibitors. The compound, on the other hand, when applied to plants (in vivo, behaved as a potent inhibitor of photosynthetic electron transport. The major site of its action was identified to be the Q(B; the secondary quinone moiety of photosystemII complex. Analysis of photoreduction kinetics of para-benzoquinone and duroquinone suggest that the inhibition leads to formation of low pool of plastoquinol, which becomes limiting for electron flow through photosystemI. Further it was ascertained that the in vivo inhibitory effect appeared as a consequence of the formation of an unidentified artemisinin-metabolite rather than by the interaction of the compound per se. The putative metabolite of artemisinin is highly reactive in instituting the inhibition of photosynthetic electron flow eventually reducing the plant growth.

  14. Allergen immunotherapy: routes, safety,efficacy, and mode of action

    Directory of Open Access Journals (Sweden)

    Hochfelder JL

    2013-07-01

    Full Text Available Jillian Leigh Hochfelder, Punita PondaDivision of Allergy and Immunology, North Shore–Long Island Jewish Health System, New Hyde Park, NY, USAAbstract: Allergic rhinitis, allergic conjunctivitis, and allergic asthma have been steadily increasing in prevalence in recent years. These allergic diseases have a major impact on quality of life and are a major economic burden in the US. Although allergen avoidance and pharmacotherapy are currently the mainstays of therapy, they are not always successful in treating patients’ symptoms effectively. If a patient fails allergen avoidance and medical therapy, immunotherapy may be indicated. Furthermore, immunotherapy is the only therapy that may change the course of the disease and induce long-term remission. Though subcutaneous administration has been the standard route for immunotherapy for many decades, there are several other routes of administration that have been and are currently being studied. The goal of utilizing alternative routes of immunotherapy is to improve safety without decreasing the efficacy of treatment. This paper will review the novel routes of immunotherapy, including sublingual, oral, local nasal, epicutaneous, and intralymphatic.Keywords: immunotherapy, allergic rhinitis, allergic asthma, sublingual, intralymphatic

  15. Taxonomic etymology – in search of inspiration

    Directory of Open Access Journals (Sweden)

    Piotr Jozwiak

    2015-07-01

    Full Text Available We present a review of the etymology of zoological taxonomic names with emphasis on the most unusual examples. The names were divided into several categories, starting from the most common – given after morphological features – through inspiration from mythology, legends, and classic literature but also from fictional and nonfictional pop-culture characters (e.g., music, movies or cartoons, science, and politics. A separate category includes zoological names created using word-play and figures of speech such as tautonyms, acronyms, anagrams, and palindromes. Our intention was to give an overview of possibilities of how and where taxonomists can find the inspirations that will be consistent with the ICZN rules and generate more detail afterthought about the naming process itself, the meaningful character of naming, as well as the recognition and understanding of names.

  16. Comparative analysis of pharmaceuticals versus industrial chemicals acute aquatic toxicity classification according to the United Nations classification system for chemicals. Assessment of the (Q)SAR predictability of pharmaceuticals acute aquatic toxicity and their predominant acute toxic mode-of-action.

    Science.gov (United States)

    Sanderson, Hans; Thomsen, Marianne

    2009-06-01

    Pharmaceuticals have been reported to be ubiquitously present in surface waters prompting concerns of effects of these bioactive substances. Meanwhile, there is a general scarcity of publicly available ecotoxicological data concerning pharmaceuticals. The aim of this paper was to compile a comprehensive database based on OECD's standardized measured ecotoxicological data and to evaluate if there is generally cause of greater concern with regards to pharmaceutical aquatic toxicological profiles relative to industrial chemicals. Comparisons were based upon aquatic ecotoxicity classification under the United Nations Global Harmonized System for classification and labeling of chemicals (GHS). Moreover, we statistically explored whether the predominant mode-of-action (MOA) for pharmaceuticals is narcosis. We found 275 pharmaceuticals with 569 acute aquatic effect data; 23 pharmaceuticals had chronic data. Pharmaceuticals were found to be more frequent than industrial chemicals in GHS category III. Acute toxicity was predictable (>92%) using a generic (Q)SAR ((Quantitative) Structure Activity Relationship) suggesting a narcotic MOA. Analysis of model prediction error suggests that 68% of the pharmaceuticals have a non-specific MOA. Additionally, the acute-to-chronic ratio (ACR) for 70% of the analyzed pharmaceuticals was below 25 further suggesting a non-specific MOA. Sub-lethal receptor-mediated effects may however have a more specific MOA.

  17. A Falsification of the Citation Impediment in the Taxonomic Literature.

    Science.gov (United States)

    Steiner, Florian M; Pautasso, Marco; Zettel, Herbert; Moder, Karl; Arthofer, Wolfgang; Schlick-Steiner, Birgit C

    2015-09-01

    Current science evaluation still relies on citation performance, despite criticisms of purely bibliometric research assessments. Biological taxonomy suffers from a drain of knowledge and manpower, with poor citation performance commonly held as one reason for this impediment. But is there really such a citation impediment in taxonomy? We compared the citation numbers of 306 taxonomic and 2291 non-taxonomic research articles (2009-2012) on mosses, orchids, ciliates, ants, and snakes, using Web of Science (WoS) and correcting for journal visibility. For three of the five taxa, significant differences were absent in citation numbers between taxonomic and non-taxonomic papers. This was also true for all taxa combined, although taxonomic papers received more citations than non-taxonomic ones. Our results show that, contrary to common belief, taxonomic contributions do not generally reduce a journal's citation performance and might even increase it. The scope of many journals rarely featuring taxonomy would allow editors to encourage a larger number of taxonomic submissions. Moreover, between 1993 and 2012, taxonomic publications accumulated faster than those from all biological fields. However, less than half of the taxonomic studies were published in journals in WoS. Thus, editors of highly visible journals inviting taxonomic contributions could benefit from taxonomy's strong momentum. The taxonomic output could increase even more than at its current growth rate if: (i) taxonomists currently publishing on other topics returned to taxonomy and (ii) non-taxonomists identifying the need for taxonomic acts started publishing these, possibly in collaboration with taxonomists. Finally, considering the high number of taxonomic papers attracted by the journal Zootaxa, we expect that the taxonomic community would indeed use increased chances of publishing in WoS indexed journals. We conclude that taxonomy's standing in the present citation-focused scientific landscape could

  18. Contrasting responses of functional diversity to major losses in taxonomic diversity.

    Science.gov (United States)

    Edie, Stewart M; Jablonski, David; Valentine, James W

    2018-01-23

    Taxonomic diversity of benthic marine invertebrate shelf species declines at present by nearly an order of magnitude from the tropics to the poles in each hemisphere along the latitudinal diversity gradient (LDG), most steeply along the western Pacific where shallow-sea diversity is at its tropical maximum. In the Bivalvia, a model system for macroevolution and macroecology, this taxonomic trend is accompanied by a decline in the number of functional groups and an increase in the evenness of taxa distributed among those groups, with maximum functional evenness (FE) in polar waters of both hemispheres. In contrast, analyses of this model system across the two era-defining events of the Phanerozoic, the Permian-Triassic and Cretaceous-Paleogene mass extinctions, show only minor declines in functional richness despite high extinction intensities, resulting in a rise in FE owing to the persistence of functional groups. We hypothesize that the spatial decline of taxonomic diversity and increase in FE along the present-day LDG primarily reflect diversity-dependent factors, whereas retention of almost all functional groups through the two mass extinctions suggests the operation of diversity-independent factors. Comparative analyses of different aspects of biodiversity thus reveal strongly contrasting biological consequences of similarly severe declines in taxonomic diversity and can help predict the consequences for functional diversity among different drivers of past, present, and future biodiversity loss.

  19. Taxonomic and chemical assessment of exceptionally abundant rock mine biofilm

    Directory of Open Access Journals (Sweden)

    Karolina Tomczyk-Żak

    2017-08-01

    Full Text Available Background An exceptionally thick biofilm covers walls of ancient gold and arsenic Złoty Stok mine (Poland in the apparent absence of organic sources of energy. Methods and Results We have characterized this microbial community using culture-dependent and independent methods. We sequenced amplicons of the 16S rRNA gene obtained using generic primers and additional primers targeted at Archaea and Actinobacteria separately. Also, we have cultured numerous isolates from the biofilm on different media under aerobic and anaerobic conditions. We discovered very high biodiversity, and no single taxonomic group was dominant. The majority of almost 4,000 OTUs were classified above genus level indicating presence of novel species. Elemental analysis, performed using SEM-EDS and X-ray, of biofilm samples showed that carbon, sulphur and oxygen were not evenly distributed in the biofilm and that their presence is highly correlated. However, the distribution of arsenic and iron was more flat, and numerous intrusions of elemental silver and platinum were noted, indicating that microorganisms play a key role in releasing these elements from the rock. Conclusions Altogether, the picture obtained throughout this study shows a very rich, complex and interdependent system of rock biofilm. The chemical heterogeneity of biofilm is a likely explanation as to why this oligotrophic environment is capable of supporting such high microbial diversity.

  20. Taxonomic significance of leaf epidermal anatomy of selected ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... Taxonomic significance of leaf epidermal anatomy of selected Persicaria Mill. species of family ... characters are comparable over a wide taxonomic range and quite reliable. Comprehensive foliar anatomy .... characteristics of the plants growing in humid conditions. (Stace, 1965; Ayodele and Olwokudejo, ...

  1. Predicting taxonomic and functional structure of microbial communities in acid mine drainage.

    Science.gov (United States)

    Kuang, Jialiang; Huang, Linan; He, Zhili; Chen, Linxing; Hua, Zhengshuang; Jia, Pu; Li, Shengjin; Liu, Jun; Li, Jintian; Zhou, Jizhong; Shu, Wensheng

    2016-06-01

    Predicting the dynamics of community composition and functional attributes responding to environmental changes is an essential goal in community ecology but remains a major challenge, particularly in microbial ecology. Here, by targeting a model system with low species richness, we explore the spatial distribution of taxonomic and functional structure of 40 acid mine drainage (AMD) microbial communities across Southeast China profiled by 16S ribosomal RNA pyrosequencing and a comprehensive microarray (GeoChip). Similar environmentally dependent patterns of dominant microbial lineages and key functional genes were observed regardless of the large-scale geographical isolation. Functional and phylogenetic β-diversities were significantly correlated, whereas functional metabolic potentials were strongly influenced by environmental conditions and community taxonomic structure. Using advanced modeling approaches based on artificial neural networks, we successfully predicted the taxonomic and functional dynamics with significantly higher prediction accuracies of metabolic potentials (average Bray-Curtis similarity 87.8) as compared with relative microbial abundances (similarity 66.8), implying that natural AMD microbial assemblages may be better predicted at the functional genes level rather than at taxonomic level. Furthermore, relative metabolic potentials of genes involved in many key ecological functions (for example, nitrogen and phosphate utilization, metals resistance and stress response) were extrapolated to increase under more acidic and metal-rich conditions, indicating a critical strategy of stress adaptation in these extraordinary communities. Collectively, our findings indicate that natural selection rather than geographic distance has a more crucial role in shaping the taxonomic and functional patterns of AMD microbial community that readily predicted by modeling methods and suggest that the model-based approach is essential to better understand natural

  2. Taxonomic significance of trichomes micromorphology in cucurbits

    Science.gov (United States)

    Ali, Mohammad Ajmal; Al-Hemaid, Fahad M.A.

    2010-01-01

    Studies on trichomes micromorphology using Scanning Electron Microscope (SEM) were undertaken in 23 species with one variety under 13 genera of the family Cucurbitaceae (viz., Benincasa hispida (Thunb.) Cogn., Citrullus lanatus (Thunb.) Matsum. & Nakai, Cucumis melo var. agrestis Naudin, Cucumis sativus L., Diplocyclos palmatus (L.) C. Jeffrey, Edgaria dargeelingensis C.B. Clarke, Gynostemma burmanicum King ex Chakr., Gynostemma pentaphyllum (Thunb.) Makino, Gynostemma pubescens (Gagnep.) C.Y. Wu, Hemsleya dipterygia Kuang & A.M. Lu, Lagenaria siceraria (Molina) Standl., Luffa acutangula (L.) Roxb., Luffa cylindrica M. Roem., Luffa echinata Roxb., Melothria heterophylla (Lour.) Cogn., Melothria leucocarpa (Blume) Cogn., Melothria maderspatana (L.) Cogn., Sechium edule (Jacq.) Sw., Thladiantha cordifolia (Blume) Cogn., Trichosanthes cucumerina L., T. cucumerina var. anguina (L.) Haines, Trichosanthes dioica Roxb., Trichosanthes lepiniana (Naudin) Cogn. and T. tricuspidata Lour.). The trichomes in the family Cucurbitaceae vary from unicellular to multicellular, conical to elongated, smooth to ridges, with or without flattened disk at base and cyctolithic appendages, thin to thick walled, curved at apices to blunt. Trichomes micromorphology in the family Cucurbitaceae was found significant taxonomically. PMID:23961108

  3. Taxonomic significance of trichomes micromorphology in cucurbits.

    Science.gov (United States)

    Ali, Mohammad Ajmal; Al-Hemaid, Fahad M A

    2011-01-01

    Studies on trichomes micromorphology using Scanning Electron Microscope (SEM) were undertaken in 23 species with one variety under 13 genera of the family Cucurbitaceae (viz., Benincasa hispida (Thunb.) Cogn., Citrullus lanatus (Thunb.) Matsum. & Nakai, Cucumis melo var. agrestis Naudin, Cucumis sativus L., Diplocyclos palmatus (L.) C. Jeffrey, Edgaria dargeelingensis C.B. Clarke, Gynostemma burmanicum King ex Chakr., Gynostemma pentaphyllum (Thunb.) Makino, Gynostemma pubescens (Gagnep.) C.Y. Wu, Hemsleya dipterygia Kuang & A.M. Lu, Lagenaria siceraria (Molina) Standl., Luffa acutangula (L.) Roxb., Luffa cylindrica M. Roem., Luffa echinata Roxb., Melothria heterophylla (Lour.) Cogn., Melothria leucocarpa (Blume) Cogn., Melothria maderspatana (L.) Cogn., Sechium edule (Jacq.) Sw., Thladiantha cordifolia (Blume) Cogn., Trichosanthes cucumerina L., T. cucumerina var. anguina (L.) Haines, Trichosanthes dioica Roxb., Trichosanthes lepiniana (Naudin) Cogn. and T. tricuspidata Lour.). The trichomes in the family Cucurbitaceae vary from unicellular to multicellular, conical to elongated, smooth to ridges, with or without flattened disk at base and cyctolithic appendages, thin to thick walled, curved at apices to blunt. Trichomes micromorphology in the family Cucurbitaceae was found significant taxonomically.

  4. Taxonomical analysis of Spanish journalism portals

    Directory of Open Access Journals (Sweden)

    Rosana López Carreño

    2004-01-01

    Full Text Available Internet has made the structures of the traditional mass media to stagger, having generated new communicative models among which the journalistic portals outstand as the most relevant examples. The present situation is the result of an evolutionary process, although the popularity of the Internet has recently caused a true outbreak. It is advisable, however, to carry out an exhaustive revision of the whole evolution of Digital Journalism up to today’s standards, with the journalistic portals turning into the new and independent mass media. A sensible perception of the this fact calls for a taxonomic analysis of the components of the portals: informative products, documentary products and added value services. This analysis will enable us to define the degree of development of these portals. The final result of this revision should provide a model of reference for the designing and developing of Journalistic Portals, based upon a series of development levels that will grant a methodology background for future projects in this field

  5. Controlling the taxonomic variable: Taxonomic concept resolution for a southeastern United States herbarium portal

    Directory of Open Access Journals (Sweden)

    Nico Franz

    2016-09-01

    Full Text Available Overview. Taxonomic names are imperfect identifiers of specific and sometimes conflicting taxonomic perspectives in aggregated biodiversity data environments. The inherent ambiguities of names can be mitigated using syntactic and semantic conventions developed under the taxonomic concept approach. These include: (1 representation of taxonomic concept labels (TCLs: name sec. source to precisely identify name usages and meanings, (2 use of parent/child relationships to assemble separate taxonomic perspectives, and (3 expert provision of Region Connection Calculus articulations (RCC–5: congruence, [inverse] inclusion, overlap, exclusion that specify how data identified to different-sourced TCLs can be integrated. Application of these conventions greatly increases trust in biodiversity data networks, most of which promote unitary taxonomic 'syntheses' that obscure the actual diversity of expert-held views. Better design solutions allow users to control the taxonomic variable and thereby assess the robustness of their biological inferences under different perspectives. A unique constellation of prior efforts – including the powerful Symbiota collections software platform, the Euler/X multi-taxonomy alignment toolkit, and the "Weakley Flora" which entails 7,000 concepts and more than 75,000 RCC–5 articulations – provides the opportunity to build a first full-scale concept resolution service for SERNEC, the SouthEast Regional Network of Expertise and Collections, currently with 60 member herbaria and 2 million occurrence records. Intellectual merit. We have developed a multi-dimensional, step-wise plan to transition SERNEC's data culture from name- to concept-based practices. (1 We will engage SERNEC experts through annual, regional workshops and follow-up interactions that will foster buy-in and ultimately the completion of 12 community-identified use cases. (2. We will leverage RCC–5 data from the Weakley Flora and further development of

  6. Efeito e modo de ação das bacteriocinas produzidas por Lactococcus lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 contra Listeria innocua LIN 11 Effect and mode of action of the bacterioncin produced by Lactococcus. lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 against Listeria innocua LIN 11

    Directory of Open Access Journals (Sweden)

    Izildinha MORENO

    1999-01-01

    Full Text Available O efeito e o modo de ação das bacteriocinas produzidas por L. lactis subsp. lactis ITAL 383 e CNRZ 150 são similares à nisina de L. lactis subsp. lactis ATCC 11454. Estas bacteriocinas apresentaram um modo de ação bactericida, causando a lise de células de L. innocua LIN 11, associada ao decréscimo da absorbância e da viabilidade celular. O efeito letal foi maior para células em fase exponencial comparativamente à fase estacionária de crescimento. A adsorção dessas bacteriocinas às células de L. innocua LIN 11 foi muito rápida e influenciada pelo pH do meio de suspensão; adsorção máxima foi verificada a pH 6,0 e logo após o contato inicial. Perda completa de adsorção ocorreu em pH 2,0.The effect and mode of action of the bacteriocin produced by L. lactis subsp. lactis ITAL 383 and CNRZ 150 are similar to the nisin produced by L. lactis subsp. lactis ATCC 11454. It was clearly bactericidal, and caused lysis of a strain of L. innocua LIN 11 detected by the decrease of absorbance values and the cell viability. Their lethal effect was considerably higher during the logarithmic growth when compared to the stationary phase. Adsorption developed rapidly and was influenced by the pH value of the suspension medium. Maximum adsorption was observed at pH 6,0 and immediately after initial contact and loss at pH 2,0.

  7. Taxonomic chauvinism revisited: insight from parental care research.

    Directory of Open Access Journals (Sweden)

    Zachary R Stahlschmidt

    Full Text Available Parental care (any non-genetic contribution by a parent that appears likely to increase the fitness of its offspring is a widespread trait exhibited by a broad range of animal taxa. In addition to influencing the fitness of parent(s and offspring, parental care may be inextricably involved in other evolutionary processes, such as sexual selection and the evolution of endothermy. Yet, recent work has demonstrated that bias related to taxonomy is prevalent across many biological disciplines, and research in parental care may be similarly burdened. Thus, I used parental care articles published in six leading journals of fundamental behavioral sciences (Animal Behaviour, Behavioral Ecology, Behavioral Ecology and Sociobiology, Ethology, Hormones and Behavior, and Physiology & Behavior from 2001-2010 (n = 712 to examine the year-to-year dynamics of two types of bias related to taxonomy across animals: (1 taxonomic bias, which exists when research output is not proportional to the frequency of organisms in nature, and (2 taxonomic citation bias, which is a proxy for the breadth of a given article-specifically, the proportion of articles cited that refer solely to the studied taxon. I demonstrate that research on birds likely represents a disproportionate amount of parental care research and, thus, exhibits taxonomic bias. Parental care research on birds and mammals also refers to a relatively narrow range of taxonomic groups when discussing its context and, thus, exhibits taxonomic citation bias. Further, the levels of taxonomic bias and taxonomic citation bias have not declined over the past decade despite cautionary messages about similar bias in related disciplines--in fact, taxonomic bias may have increased. As in Bonnet et al. (2002, my results should not be interpreted as evidence of an 'ornithological Mafia' conspiring to suppress other taxonomic groups. Rather, I generate several rational hypotheses to determine why bias persists and to

  8. Concordant Biogeographic Patterns among Multiple Taxonomic Groups in the Mexican Freshwater Biota

    Science.gov (United States)

    Quiroz-Martínez, Benjamín; Álvarez, Fernando; Espinosa, Héctor; Salgado-Maldonado, Guillermo

    2014-01-01

    In this paper we analyse the degree of concordance in species richness and taxonomic distinctness (diversity) patterns among different freshwater taxonomic groups in order to test three long held patterns described in Mexican freshwater biogeography: 1. The aquatic biota of Mexico includes two distinct faunas, a rich Neotropical component in the south and a south-eastern region and a less rich Nearctic component towards central and northern latitudes of the country. 2. A hotspot of species richness and diversity has been recorded in the Usumacinta, including the Yucatan Peninsula. 3. The presence of two distinct biotas in Mexico, an eastern one distributed along the Gulf of Mexico slope, and a western one associated to the Pacific versant. We use species richness and taxonomic distinctness to explore patterns of diversity and how these patterns change between zoogeographical regions. This paper points out a clear separation between Neotropical and Nearctic drainage basins but also between eastern (Gulf of Mexico) and western (Pacific) drainage basins. Present data gives additional empirical support from freshwater biota for three long held beliefs regarding distributional patterns of the Mexican biota. The neotropical basins of Mexico are generally host to a richest and more diversified fauna, that includes more families, genera and species, compared to the less rich and less diverse fauna in the nearctic basins. PMID:25136979

  9. A taxonomic study on the diversity of Indian Knema Lour. (Myristicaceae

    Directory of Open Access Journals (Sweden)

    Dipanwita Banik

    2016-06-01

    Full Text Available A taxonomic study on the diversity of the genus Knema Lour. belonging to the family Myristicaceae R. Br. in India revealed the distribution of the ten taxa under four series in North East and Peninsular India and Andaman and Nicobar Islands including two endemic species. Knema ser. Obovoideae W.J. de Wilde is synonymised here under ser. Knema. Series Knema is represented by two species and ser. Glaucae W.J. de Wilde by one species in North East India, while ser. Laurinae W.J. de Wilde is represented by three species and two subspecies in North East India and Andaman and Nicobar Island, and ser. Glomeratae W.J. de Wilde by 2 species in South and NE India. This is the first taxonomic study on the genus in India. All the taxa are cited with updated nomenclature, diagnostic characters, distribution, phonological data, vernacular names, line drawings, photo plates and specimens examined in various herbaria. Taxonomic keys are provided for easy identification of these taxa.

  10. Genome-Based Taxonomic Classification of Bacteroidetes

    Science.gov (United States)

    Hahnke, Richard L.; Meier-Kolthoff, Jan P.; García-López, Marina; Mukherjee, Supratim; Huntemann, Marcel; Ivanova, Natalia N.; Woyke, Tanja; Kyrpides, Nikos C.; Klenk, Hans-Peter; Göker, Markus

    2016-01-01

    The bacterial phylum Bacteroidetes, characterized by a distinct gliding motility, occurs in a broad variety of ecosystems, habitats, life styles, and physiologies. Accordingly, taxonomic classification of the phylum, based on a limited number of features, proved difficult and controversial in the past, for example, when decisions were based on unresolved phylogenetic trees of the 16S rRNA gene sequence. Here we use a large collection of type-strain genomes from Bacteroidetes and closely related phyla for assessing their taxonomy based on the principles of phylogenetic classification and trees inferred from genome-scale data. No significant conflict between 16S rRNA gene and whole-genome phylogenetic analysis is found, whereas many but not all of the involved taxa are supported as monophyletic groups, particularly in the genome-scale trees. Phenotypic and phylogenomic features support the separation of Balneolaceae as new phylum Balneolaeota from Rhodothermaeota and of Saprospiraceae as new class Saprospiria from Chitinophagia. Epilithonimonas is nested within the older genus Chryseobacterium and without significant phenotypic differences; thus merging the two genera is proposed. Similarly, Vitellibacter is proposed to be included in Aequorivita. Flexibacter is confirmed as being heterogeneous and dissected, yielding six distinct genera. Hallella seregens is a later heterotypic synonym of Prevotella dentalis. Compared to values directly calculated from genome sequences, the G+C content mentioned in many species descriptions is too imprecise; moreover, corrected G+C content values have a significantly better fit to the phylogeny. Corresponding emendations of species descriptions are provided where necessary. Whereas most observed conflict with the current classification of Bacteroidetes is already visible in 16S rRNA gene trees, as expected whole-genome phylogenies are much better resolved. PMID:28066339

  11. The cost of switching between taxonomic and thematic semantics.

    Science.gov (United States)

    Landrigan, Jon-Frederick; Mirman, Daniel

    2018-02-01

    Current models and theories of semantic knowledge primarily capture taxonomic relationships (DOG and WOLF) and largely do not address the role of thematic relationships in semantic knowledge (DOG and LEASH). Recent evidence suggests that processing or representation of thematic relationships may be distinct from taxonomic relationships. If taxonomic and thematic relations are distinct, then there should be a cost associated with switching between them even when the task remains constant. This hypothesis was tested using two different semantic-relatedness judgment tasks: Experiment 1 used a triads task and Experiment 2 used an oddball task. In both experiments, participants were faster to respond when the same relationship appeared on consecutive trials than when the relationship types were different, even though the task remained the same and the specific relations were different on each trial. These results are consistent with the theory that taxonomic and thematic relations rely on distinct processes or representations.

  12. Taxonomic and phylogenetic utility of variation in advertising calls of ...

    African Journals Online (AJOL)

    Taxonomic and phylogenetic utility of variation in advertising calls of francolins and spurfowls (Galliformes: Phasianidae). Tshifhiwa G. Mandiwana-Neudani, Rauri C.K. Bowie, Martine Hausberger, Laurence Henry, Timothy M. Crowe ...

  13. Taxonomic colouring of phylogenetic trees of protein sequences

    Directory of Open Access Journals (Sweden)

    Andrade-Navarro Miguel A

    2006-02-01

    Full Text Available Abstract Background Phylogenetic analyses of protein families are used to define the evolutionary relationships between homologous proteins. The interpretation of protein-sequence phylogenetic trees requires the examination of the taxonomic properties of the species associated to those sequences. However, there is no online tool to facilitate this interpretation, for example, by automatically attaching taxonomic information to the nodes of a tree, or by interactively colouring the branches of a tree according to any combination of taxonomic divisions. This is especially problematic if the tree contains on the order of hundreds of sequences, which, given the accelerated increase in the size of the protein sequence databases, is a situation that is becoming common. Results We have developed PhyloView, a web based tool for colouring phylogenetic trees upon arbitrary taxonomic properties of the species represented in a protein sequence phylogenetic tree. Provided that the tree contains SwissProt, SpTrembl, or GenBank protein identifiers, the tool retrieves the taxonomic information from the corresponding database. A colour picker displays a summary of the findings and allows the user to associate colours to the leaves of the tree according to any number of taxonomic partitions. Then, the colours are propagated to the branches of the tree. Conclusion PhyloView can be used at http://www.ogic.ca/projects/phyloview/. A tutorial, the software with documentation, and GPL licensed source code, can be accessed at the same web address.

  14. Taxonomic revision of Beilschmiedia (Lauraceae) in Borneo

    NARCIS (Netherlands)

    Nishida, S.

    2008-01-01

    A revision of Beilschmiedia Nees (Lauraceae) in Borneo is given. Descriptions, distribution maps, illustrations of leaves, terminal buds, and flowers, and a key to the species are provided. Twenty-six species were recognized, including one newly described species. The new species is distinguished

  15. Taxonomic distinctness and richness of helminth parasite assemblages of freshwater fishes in Mexican hydrological basins.

    Directory of Open Access Journals (Sweden)

    Benjamín Quiroz-Martínez

    Full Text Available In this paper, we analyse the distributional patterns of adult helminth parasites of freshwater fishes with respect to the main hydrological basins of Mexico. We use the taxonomic distinctness and the variation in taxonomic distinctness to explore patterns of parasite diversity and how these patterns change between zoogeographical regions. We address questions about the factors that determine the variation of observed diversity of helminths between basins. We also investigate patterns of richness, taxonomic distinctness and distance decay of similarity amongst basins. Our analyses suggest that the evolution of the fauna of helminth parasites in Mexico is mostly dominated by independent host colonization events and that intra--host speciation could be a minor factor explaining the origin of this diversity. This paper points out a clear separation between the helminth faunas of northern--nearctic and southern--neotropical components in Mexican continental waters, suggesting the availability of two distinct taxonomic pools of parasites in Mexican drainage basins. Data identifies Mexican drainage basins as unities inhabited by freshwater fishes, hosting a mixture of neotropical and nearctic species, in addition, data confirms neotropical and neartic basins/helminth faunas. The neotropical basins of Mexico are host to a richest and more diversified helminth fauna, including more families, genera and species, compared to the less rich and less diverse helminth fauna in the nearctic basins. The present analysis confirms distance--decay as one of the important factors contributing to the patterns of diversity observed. The hypothesis that helminth diversity could be explained by the ichthyological diversity of the basin received no support from present analysis.

  16. Marine actinomycetes from Madeira Archipelago preliminary taxonomic studies

    Directory of Open Access Journals (Sweden)

    Ilda Santos Sanches

    2014-06-01

    region and suggesting a more globally distribution of this genus than previously supposed (unplublished results. In this study further 82 strains from Madeira Archipelago (out of 421 were selected for taxonomic identification, taking into account small groups of strains (1-4 evidencing very diverse morphological appearances, as exemplified in Figure 2. Using the same experimental microbiology identification tools, 8 genera were identified. However it was perceived that, the genera Streptomyces, Nocardiopsis and Actinomycetospora were predominant (93%, Figure 3. The phylogenetic trees built for the 82 taxonomically identified strains performed in this study are presented in Figures 4, 5 and 6. To date, having into account the present work and previous studies, our research group have identified from the actinomycetes isolated from Madeira´s ocean sediments, genera Streptomyces, Micromonospora, Salinispora, Nocardiopsis, Verrucosispora, Kocuria, Nonomuraea, Nocardia, Brevibacterium, Mycobacterium, Marinobacter, Actinomadura, Micrococcus, Actinomycetospora, Pseudonocardia, Gordonia and Millisia. From which genera Streptomyces, Micromonospora, Salinispora evidence a major representation. Crude extracts were obtained from all 421 strains and tested for their ability to produce natural products with bioactive properties: (i antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA, vancomycin-resistant Enterococcus faecalis (VRE and Candida albicans strains; and (ii cytotoxic activity against the HCT-116 cell line. A screening positive rate of 2.4% for antimicrobial MRSA and VRE assays and 3.2% for cytotoxic HCT-116 assay was obtained (submitted manuscripts. These studies demonstrate that the Macaronesian Atlantic Ocean region is a rich source of marine actinomycete biodiversity with potential industrial applications. Figure 1. Marine actinomycetes sediment sampling locations at Madeira Archipelago. Figure 2. Morphological diversity characteristics of

  17. Taxonomic bias in biodiversity data and societal preferences.

    Science.gov (United States)

    Troudet, Julien; Grandcolas, Philippe; Blin, Amandine; Vignes-Lebbe, Régine; Legendre, Frédéric

    2017-08-22

    Studying and protecting each and every living species on Earth is a major challenge of the 21 st century. Yet, most species remain unknown or unstudied, while others attract most of the public, scientific and government attention. Although known to be detrimental, this taxonomic bias continues to be pervasive in the scientific literature, but is still poorly studied and understood. Here, we used 626 million occurrences from the Global Biodiversity Information Facility (GBIF), the biggest biodiversity data portal, to characterize the taxonomic bias in biodiversity data. We also investigated how societal preferences and taxonomic research relate to biodiversity data gathering. For each species belonging to 24 taxonomic classes, we used the number of publications from Web of Science and the number of web pages from Bing searches to approximate research activity and societal preferences. Our results show that societal preferences, rather than research activity, strongly correlate with taxonomic bias, which lead us to assert that scientists should advertise less charismatic species and develop societal initiatives (e.g. citizen science) that specifically target neglected organisms. Ensuring that biodiversity is representatively sampled while this is still possible is an urgent prerequisite for achieving efficient conservation plans and a global understanding of our surrounding environment.

  18. A taxonomic review of the dry-fruited species of Anemone (Ranunculaceae in southern Africa

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2013-01-01

    Full Text Available The three dry-fruited species of Anemone sect. Pulsatilloides subsect. Alchemillifoliae (Ranunculaceae from southern Africa are reviewed, with full descriptions and nomenclature, including complete synonomy, taxonomic history with nomenclatural corrections, ecological notes, and distribution. A. tenuifolia (L.f. DC. from the Cape Floristic Region is segregated as ser. Pinnatifoliae from the two summer rainfall species, A. caffra (Eckl. & Zeyh. Harv. and A. fanninnii Harv. ex Masters, which remain in ser. Alchemillifoliae, emphasising the strong vegetative differences between the two series.

  19. Three reciprocally monophyletic mtDNA lineages elucidate the taxonomic status of Grant's gazelles

    DEFF Research Database (Denmark)

    Lorenzen, Eline Deidre; Arctander, Peter; Siegismund, Hans Redlef

    2008-01-01

    are discussed in reference to the four currently recognised subspecies. We suggest Grant's gazelles be raised to the superspecies Nanger (granti) comprising three taxonomic units corresponding to the three mtDNA lineages. There was no evidence of gene flow between the notata and granti lineages, despite...... their geographic proximity, suggesting reproductive isolation. These constitute evolutionary significant units within the adaptive evolutionary framework. Due to its restricted geographic distribution and genetic and morphological distinctiveness, we suggest the petersii lineage be raised to the species Nanger...

  20. Taxonomic study of Festuca L. subgenus Schedonorus (P. Beauv. Peterm. in Iran

    Directory of Open Access Journals (Sweden)

    Sayed Zabihollah Hosseini

    2013-11-01

    Full Text Available This study was based upon a taxonomic review of the subgenus Schedonorus in Iran. A collection of 30 specimens belonging to the herbaria: W, B and HUI (herbarium of the University of Isfahan were studied. Based on the results of this study, this subgenus included three species: Festuca arundinacea, F. gigantea and F. pratensis in Iran. Furthermore, this study showed that F. arundinacea, occured in this country with two subspecies: orientalis (Hack. Tzvelev and fenas (Lag. Arcang. with the greatest area of distribution compared to the other two species. Our examination of the type specimen of F. elatior subsp. pratensis var. elbursiana confirmed its synonymy with F. arundinacea.

  1. Taxonomic revision of Galeocharax (Characiformes: Characidae: Characinae

    Directory of Open Access Journals (Sweden)

    Victor Giovannetti

    2017-03-01

    Full Text Available ABSTRACT The taxonomy of Galeocharax, a genus of freshwater fishes distributed in most South American cis-Andean river systems, except the rio Negro, rio São Francisco and rio Xingu basins and the eastern drainages of Brazil, is herein revised. A total of 1229 specimens were examined from which 680 had meristic and morphometric data taken. Osteological and morphological features were also examined through radiographs, scanning electron microscopy and in cleared and stained specimens. Three of the four species previously considered as valid are herein recognized: Galeocharax humeralis from rio Paraguay and lower rio Paraná basins; Galeocharax goeldii, from rio Madeira basin, with records of geographical distribution expanded to the río Madre de Dios, río Beni, rio Mamoré and rio Guaporé basins and Galeocharax gulo, which is widespread throughout rio Amazonas, río Orinoco, rio Tocantins, and upper rio Paraná basins. Galeocharax knerii is herein considered a junior synonym of Galeocharax gulo. A key to species of Galeocharax is presented.

  2. Hypothesis testing and power calculations for taxonomic-based human microbiome data.

    Science.gov (United States)

    La Rosa, Patricio S; Brooks, J Paul; Deych, Elena; Boone, Edward L; Edwards, David J; Wang, Qin; Sodergren, Erica; Weinstock, George; Shannon, William D

    2012-01-01

    This paper presents new biostatistical methods for the analysis of microbiome data based on a fully parametric approach using all the data. The Dirichlet-multinomial distribution allows the analyst to calculate power and sample sizes for experimental design, perform tests of hypotheses (e.g., compare microbiomes across groups), and to estimate parameters describing microbiome properties. The use of a fully parametric model for these data has the benefit over alternative non-parametric approaches such as bootstrapping and permutation testing, in that this model is able to retain more information contained in the data. This paper details the statistical approaches for several tests of hypothesis and power/sample size calculations, and applies them for illustration to taxonomic abundance distribution and rank abundance distribution data using HMP Jumpstart data on 24 subjects for saliva, subgingival, and supragingival samples. Software for running these analyses is available.

  3. Hypothesis testing and power calculations for taxonomic-based human microbiome data.

    Directory of Open Access Journals (Sweden)

    Patricio S La Rosa

    Full Text Available This paper presents new biostatistical methods for the analysis of microbiome data based on a fully parametric approach using all the data. The Dirichlet-multinomial distribution allows the analyst to calculate power and sample sizes for experimental design, perform tests of hypotheses (e.g., compare microbiomes across groups, and to estimate parameters describing microbiome properties. The use of a fully parametric model for these data has the benefit over alternative non-parametric approaches such as bootstrapping and permutation testing, in that this model is able to retain more information contained in the data. This paper details the statistical approaches for several tests of hypothesis and power/sample size calculations, and applies them for illustration to taxonomic abundance distribution and rank abundance distribution data using HMP Jumpstart data on 24 subjects for saliva, subgingival, and supragingival samples. Software for running these analyses is available.

  4. Taxonomic Significance of Some Vernacular names of Okra ...

    African Journals Online (AJOL)

    The aim of this study was to examine the folk criteria used by farmers to name their local okra varieties and also to assess the taxonomic significance of vernacular names in the identification and classification of these okra varieties in Ghana. Forty two okra accessions and their vernacu-lar names were obtained from PGRRI, ...

  5. Taxonomic status of the melanistic forms of the Cordylus cordylus ...

    African Journals Online (AJOL)

    The taxonomic status of the two melanistic morphotypes belonging to the Cordylus cordylus complex in the south-western Cape, South Africa, is considered. It is proposed that the coastal melanistic form, previously described as subspecies of C. cordylus,be considered a separate species, while the previously unknown ...

  6. Taxonomic status and conservation importance of the avifauna of ...

    African Journals Online (AJOL)

    Democratic Republic of Congo) focussed on the status of 56 taxa, to reveal a high endemism (14 species of a total of at least 642). In addition, 33 taxa were also revealed as possible south-central African endemics but need thorough taxonomic ...

  7. Taxonomic studies of nodulated leguminous weeds from the flora of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... Taxonomic studies of nodulated leguminous weeds from the flora of North Western part (Dera Ismail Khan) of Pakistan. Sarfaraz Khan Marwat*, Mir Ajab Khan, Mushtaq Ahmad, Muhammad Zafar, Farooq Ahmad and Abdul Nazir. Department of Plant Sciences, Quaid-i-Azam University Islamabad, Pakistan.

  8. Taxonomical and functional microbial community selection in soybean rhizosphere

    NARCIS (Netherlands)

    Mendes, L.W.; Kuramae, E.E.; Navarrete, A.A.; Van Veen, J.A.; Tsai, S.M.

    2014-01-01

    This study addressed the selection of the rhizospheric microbial community from the bulk soil reservoir under agricultural management of soybean in Amazon forest soils. We used a shotgun metagenomics approach to investigate the taxonomic and functional diversities of microbial communities in the

  9. The biology and taxonomic status of an estuarine population of ...

    African Journals Online (AJOL)

    The biology and taxonomic status of an estuarine population of Pranesus pinguis (Lacépède) (Teleostei: Atherinidae) in south east Africa. ... The structure and dimensions of the gill rakers related to the diet indicate that, although P. pinguis feeds mainly by capturing individual prey, it is also a facultative filter feeder.

  10. Revolving SEM images visualising 3D taxonomic characters

    DEFF Research Database (Denmark)

    Akkari, Nesrine; Cheung, David Koon-Bong; Enghoff, Henrik

    2013-01-01

    A novel illustration technique based on scanning electron microscopy is used for the first time to enhance taxonomic descriptions. The male genitalia (gonopods) of six species of millipedes are used for construction of interactive imaging models. Each model is a compilation of a number of SEM ima...

  11. Taxonomic significance of leaf epidermal anatomy of selected ...

    African Journals Online (AJOL)

    Leaf epidermal anatomy of selected Persicaria Mill. species of the family Polygonaceae revealed variation in size and shape of epidermal cells, stomata, glandular and non glandular trichomes. This study proves to be taxonomically important tool in the delimitation of taxa. Epidermal cell shapes are variable but mostly ...

  12. A taxonomic revision of the Continental African Bulbophyllinae

    NARCIS (Netherlands)

    Vermeulen, J.J.

    1987-01-01

    This paper contains a taxonomic revision of the Bulbophyllinae, with the genera Bulbophyllum (including Cirrhopetalum and Megaclinium) and Chaseella, from continental Africa (including Bioko (Fernando Poo), Sao Tome, Principe, Annobon and Zanzibar). Keys are given to the genera and species. For each

  13. Developing green supply chain management strategies: A taxonomic approach

    Directory of Open Access Journals (Sweden)

    Michael Mutingi

    2013-06-01

    Full Text Available Purpose: The objective of this research is to explore the empirical green supply chain activities found in literature, and to develop a taxonomic framework that can be used for formulating appropriate strategies for green supply chains, based on characteristic dimensions for the green supply chain. Design/methodology/approach: The taxonomic framework is developed through (i analysis of green supply chain activities found in existing empirical work or case studies recorded in literature, (ii identification of key dimensions that influence green supply chain management strategies, and (iii development of a taxonomic scheme for selecting or developing green strategies. Findings: The paper finds that this study yielded: a set of three characteristic dimensions that influence strategic green supply chain management, and a guided structured approach selecting appropriate green strategies, providing managerial insights. Research limitations/implications: This paper shows that future work includes development of specific performance management indices according to the taxonomy of green strategies developed in this study. Practical implications: This research provided a practical guided approach that enhances appropriate formulation of green strategies for green supply chain management, while providing sound managerial insights for the supply chain decision maker. The choice of supply chain strategy directly impacts the overall environmental, economic and operations performance of the supply chain. Originality/value: This study presents to supply chain decision makers a new taxonomic framework that simplifies and enhances the formulation of green strategies, and to researchers a comparative understanding of various strategies applicable to green supply chains.

  14. The taxonomic status of giant sengis ( genus Rhynchocyon ) in ...

    African Journals Online (AJOL)

    The sengis (elephant-shrews) of Mozambique are poorly known, especially the taxonomic status of the giant sengis, genus Rhynchocyon. Currently, Rhynchocyon from Mozambique are thought to be chequered sengis, R. cirnei with specimens from the central coastal areas being placed in the subspecies R. c. cirnei, while ...

  15. Taxonomic Knowledge of Children with and without Cochlear Implants

    Science.gov (United States)

    Lund, Emily; Dinsmoor, Jessica

    2016-01-01

    Purpose: The purpose of this study was to compare the taxonomic vocabulary knowledge and organization of children with cochlear implants to (a) children with normal hearing matched for age, and (b) children matched for vocabulary development. Method: Ten children with cochlear implants, 10 age-matched children with normal hearing, and 10…

  16. The biology and taxonomic status of an estuarine population of ...

    African Journals Online (AJOL)

    The biology and taxonomic status of Pranesus pinguis in the sub- tropical Kosi estuary in south east Africa were investigated. Data from. Kosi specimens support the view that P. pinguis is a highly variable species in terms of fin, spines, rays and body ratios. Nearly ali the variations reported for P. pinguis by Smith (1965) ...

  17. The karyotype and taxonomic status of Cryptomys hottentotus darlingi

    African Journals Online (AJOL)

    The karyotype and taxonomic status of. Cryptomys hottentotus darlingi (Rodentia: Bath yergid ae). G.H, Aguilar. Department of ZOOlogy, University of Cape Town, Ronde- ..... Classification of southern African mammals. Transvaal Mus. MOflogr. 5: 1-359. NEVO. E .. CAP ANNA. E .. CORTI. M .. JARVIS. LU.M. &. HICKMAN.

  18. Taxonomic perspective of plant species yielding vegetable oils used ...

    African Journals Online (AJOL)

    A search conducted to determine the plants yielding vegetable oils resulted in 78 plant species with potential use in cosmetics and skin care products. The taxonomic position of these plant species is described with a description of vegetable oils from these plants and their use in cosmetic and skin care products.

  19. Taxonomic Composition of the Diet of Hawksbill Turtles ...

    African Journals Online (AJOL)

    The taxonomic composition of the diet of hawksbill turtles was determined at five locations in the Republic of Seychelles (Inner Islands, Amirantes Group, Farquhar Atoll, Cosmoledo Atoll and Aldabra Atoll) using a combination of gut samples taken from salvaged dead animals, oesophageal lavages and in-water ...

  20. Taxonomic Study of Endemic Species of Astragalus L. (Fabaceae of India

    Directory of Open Access Journals (Sweden)

    Lal Babu Chaudhary

    2007-09-01

    Full Text Available The goal of the study is to provide a comprehensive taxonomic account of 12 endemic species of Astragalus occurring in India. The north-west Himalayan region harbors more endemic species (11 spp. than eastern Himalaya where only two species have been noticed from Sikkim. Jammu & Kashmir with seven species occupies first position in the list of endemic species. Five species are strictly confined to Jammu & Kashmir, while two species to Uttaranchal and one species to Sikkim. Only one species (A. tenuicaulis is found in both the Himalayas, otherwise the elements of both the Himalayas are quite distinct from each other. Most of the endemic species of Astragalus have been observed quite rare in the nature except A. uttaranchalensis. In the present investigation, A. turgidus, a newly described species from Jammu & Kashmir, has been found conspecific to A. kashmirensis. For each species nomenclature, description, distribution, phenology, taxonomic notes, list of the investigated materials, distribution map and figures are given. A new combination A. falconeri var. pilosus (Ali Chaudhary has been proposed based on A. hoffmeisteri var. pilosus Ali. A new endemic species A. nainitalensis from Kumaon Himalaya has also been described here along with illustrations.

  1. Phi Class of Glutathione S-transferase Gene Superfamily Widely Exists in Nonplant Taxonomic Groups.

    Science.gov (United States)

    Munyampundu, Jean-Pierre; Xu, You-Ping; Cai, Xin-Zhong

    2016-01-01

    Glutathione S-transferases (GSTs) constitute a superfamily of enzymes involved in detoxification of noxious compounds and protection against oxidative damage. GST class Phi (GSTF), one of the important classes of plant GSTs, has long been considered as plant specific but was recently found in basidiomycete fungi. However, the range of nonplant taxonomic groups containing GSTFs remains unknown. In this study, the distribution and phylogenetic relationships of nonplant GSTFs were investigated. We identified GSTFs in ascomycete fungi, myxobacteria, and protists Naegleria gruberi and Aureococcus anophagefferens. GSTF occurrence in these bacteria and protists correlated with their genome sizes and habitats. While this link was missing across ascomycetes, the distribution and abundance of GSTFs among ascomycete genomes could be associated with their lifestyles to some extent. Sequence comparison, gene structure, and phylogenetic analyses indicated divergence among nonplant GSTFs, suggesting polyphyletic origins during evolution. Furthermore, in silico prediction of functional partners suggested functional diversification among nonplant GSTFs.

  2. Clarification of the taxonomic relationship of the extant and extinct ovibovids, Ovibos, Praeovibos, Euceratherium and Bootherium

    Science.gov (United States)

    Campos, Paula F.; Sher, Andrei; Mead, Jim I.; Tikhonov, Alexei; Buckley, Michael; Collins, Matthew; Willerslev, Eske; Gilbert, M. Thomas P.

    2010-08-01

    During the late Pleistocene, a large number of species colonized North America from Eurasia through the Bering Land Bridge. At least four different genera within the tribe Ovibovini are known from this time, the holarctically distributed Ovibos moschatus (the extant musk ox) and Praeovibos, and the nearctically distributed Bootherium and Euceratherium. Questions about the taxonomic relationships of the four North American musk oxen arose soon after their description and continue to be unresolved at the present. In this study we present the first DNA and protein analyses, of the four mentioned genera. Phylogenetic analysis at the mitochondrial level indicates that Praeovibos falls within the diversity of modern Ovibos, which might indicate that Praeovibos is simply an earlier morphotype of the extant species O. moschatus. In contrast Euceratherium and Bootherium are clearly distinct genera, in agreement with the findings of previous morphological studies.

  3. Leaf epidermal characters of Solanum sect. polytrichum (Solanaceae) as taxonomic evidence.

    Science.gov (United States)

    Nurit-Silva, Kiriaki; De Fátima Agra, Maria

    2011-12-01

    The morphological similarities among the species of Solanum are remarkable, and are often very difficult one clear distinction between them. This paper presents a comparative anatomical study of the leaf epidermis of five Brazilian species of Solanum sect. Polytrichum, carried out using light and scanning electron microscopy. The leaf epidermis surfaces were investigated to evaluate their taxonomic significance to be used for separation and delimitation of the species of the section. As results, some micro-morphological characters of the leaf epidermis, such as density, distribution and type of stellate trichomes, and the anticlinal walls of epidermal cells, and also the type and distribution of stomata proved to be the most useful and distinctive characters for the separation and delimitation of the species, and also may contribute as an additional support to the interspecific taxonomy and systematic of Solanum sect. Polytrichum. Copyright © 2011 Wiley Periodicals, Inc.

  4. Beta Diversity in a Highly Heterogeneous Area: Disentangling Species and Taxonomic Dissimilarity for Terrestrial Vertebrates

    Science.gov (United States)

    Calderón-Patrón, Jaime M.; Goyenechea, Irene; Ortiz-Pulido, Raúl; Castillo-Cerón, Jesús; Manriquez, Norma; Ramírez-Bautista, Aurelio; Rojas-Martínez, Alberto E.; Sánchez-Rojas, Gerardo; Zuria, Iriana

    2016-01-01

    Quantifying differences in species composition among communities provides important information related to the distribution, conservation and management of biodiversity, especially when two components are recognized: dissimilarity due to turnover, and dissimilarity due to richness differences. The ecoregions in central Mexico, within the Mexican Transition Zone, have outstanding environmental heterogeneity and harbor huge biological richness, besides differences in the origin of the biota. Therefore, biodiversity studies in this area require the use of complementary measures to achieve appropriate information that may help in the design of conservation strategies. In this work we analyze the dissimilarity of terrestrial vertebrates, and the components of turnover and richness differences, among six ecoregions in the state of Hidalgo, central Mexico. We follow two approaches: one based on species level dissimilarity, and the second on taxonomic dissimilarity. We used databases from the project “Biodiversity in the state of Hidalgo”. Our results indicate that species dissimilarity is higher than taxonomic dissimilarity, and that turnover contributes more than richness differences, both for species and taxonomic total dissimilarity. Moreover, total dissimilarity, turnover dissimilarity and the dissimilarity due to richness differences were positively related in the four vertebrate groups. Reptiles had the highest values of dissimilarity, followed by mammals, amphibians and birds. For reptiles, birds, and mammals, species turnover was the most important component, while richness differences had a higher contribution for amphibians. The highest values of dissimilarity occurred between environmentally contrasting ecoregions (i.e., tropical and temperate forests), which suggests that environmental heterogeneity and differences in the origin of biotas are key factors driving beta diversity of terrestrial vertebrates among ecoregions in this complex area. PMID:27500934

  5. Analysis of diversification: combining phylogenetic and taxonomic data.

    Science.gov (United States)

    Paradis, Emmanuel

    2003-12-07

    The estimation of diversification rates using phylogenetic data has attracted a lot of attention in the past decade. In this context, the analysis of incomplete phylogenies (e.g. phylogenies resolved at the family level but unresolved at the species level) has remained difficult. I present here a likelihood-based method to combine partly resolved phylogenies with taxonomic (species-richness) data to estimate speciation and extinction rates. This method is based on fitting a birth-and-death model to both phylogenetic and taxonomic data. Some examples of the method are presented with data on birds and on mammals. The method is compared with existing approaches that deal with incomplete phylogenies. Some applications and generalizations of the approach introduced in this paper are further discussed.

  6. Analysis of diversification: combining phylogenetic and taxonomic data.

    OpenAIRE

    Paradis, Emmanuel

    2003-01-01

    The estimation of diversification rates using phylogenetic data has attracted a lot of attention in the past decade. In this context, the analysis of incomplete phylogenies (e.g. phylogenies resolved at the family level but unresolved at the species level) has remained difficult. I present here a likelihood-based method to combine partly resolved phylogenies with taxonomic (species-richness) data to estimate speciation and extinction rates. This method is based on fitting a birth-and-death mo...

  7. La confusa taxonomía de Cryptosporidium

    Directory of Open Access Journals (Sweden)

    Gregorio Pérez-Cordón

    2006-10-01

    Full Text Available Los últimos descubrimientos en la biología y filogenética de Cryptosporidium refuerzan la necesidad de una exhaustiva revisión del ciclo de vida y la taxonomía de este parásito. Tanto futuros estudios de cultivo in vitro e in vivo así como estudios moleculares y genéticos permitirán avanzar en el profundo conocimiento de este interesante parásito.

  8. Standardizing metadata and taxonomic identification in metabarcoding studies.

    Science.gov (United States)

    Tedersoo, Leho; Ramirez, Kelly S; Nilsson, R Henrik; Kaljuvee, Aivi; Kõljalg, Urmas; Abarenkov, Kessy

    2015-01-01

    High-throughput sequencing-based metabarcoding studies produce vast amounts of ecological data, but a lack of consensus on standardization of metadata and how to refer to the species recovered severely hampers reanalysis and comparisons among studies. Here we propose an automated workflow covering data submission, compression, storage and public access to allow easy data retrieval and inter-study communication. Such standardized and readily accessible datasets facilitate data management, taxonomic comparisons and compilation of global metastudies.

  9. Taxonomic Classification for Living Organisms Using Convolutional Neural Networks

    OpenAIRE

    Khawaldeh, Saed; Pervaiz, Usama; Elsharnoby, Mohammed; Alchalabi, Alaa Eddin; Al-Zubi, Nayel

    2017-01-01

    Taxonomic classification has a wide-range of applications such as finding out more about evolutionary history. Compared to the estimated number of organisms that nature harbors, humanity does not have a thorough comprehension of to which specific classes they belong. The classification of living organisms can be done in many machine learning techniques. However, in this study, this is performed using convolutional neural networks. Moreover, a DNA encoding technique is incorporated in the algo...

  10. Rapid evolution in lekking grouse: Implications for taxonomic definitions

    Science.gov (United States)

    Oyler-McCance, Sara J.; St. John, Judy; Quinn, Thomas W.

    2010-01-01

    Species and subspecies delineations were traditionally defined by morphological and behavioral traits, as well as by plumage characteristics. Molecular genetic data have more recently been used to assess these classifications and, in many cases, to redefine them. The recent practice of utilizing molecular genetic data to examine taxonomic questions has led some to suggest that molecular genetic methods are more appropriate than traditional methods for addressing taxonomic uncertainty and management units. We compared the North American Tetraoninae—which have been defined using plumage, morphology, and behavior—and considered the effects of redefinition using only neutral molecular genetic data (mitochondrial control region and cytochrome oxidase subunit 1). Using the criterion of reciprocal monophyly, we failed to recognize the five species whose mating system is highly polygynous, with males displaying on leks. In lek-breeding species, sexual selection can act to influence morphological and behavioral traits at a rate much faster than can be tracked genetically. Thus, we suggest that at least for lek-breeding species, it is important to recognize the possibility that morphological and behavioral changes may occur at an accelerated rate compared with the processes that led to reciprocal monophyly of putatively neutral genetic markers. Therefore, it is particularly important to consider the possible disconnect between such lines of evidence when making taxonomic revisions and definitions of management units.

  11. Species of Adialytus Förster, 1862 (Hymenoptera, Braconidae, Aphidiinae in Iran: taxonomic notes and tritrophic associations

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    Ehsan Rakhshani

    2012-09-01

    Full Text Available The species of Adialytus Förster in Iran are taxonomically studied and new data on distribution and host associations are presented. The existence of a species complex, in the case of A. ambiguus (Haliday, and the morphological variability in commonly used taxonomic characters has been discussed. In total, four valid species belonging to the genus Adialytus including A. ambiguus (Haliday, A. salicaphis (Fitch, A. thelaxis (Starý and A. veronicaecola (Starý have been identified and recorded from Iran. Also, we recognized two additional phenotypes: “A. arvicola” (Starý and “Adialytus cf. ambiguus” (Haliday. These phenotypes and A. veronicaecola are newly recorded from Iran in association with Sipha and Aphis species, respectively. An illustrated key for identification of the species and two variable phenotypes is presented.

  12. A taxonomic survey of Saudi Arabian Red Sea octocorals (Cnidaria: Alcyonacea)

    KAUST Repository

    Haverkort-Yeh, Roxanne D.

    2013-05-04

    A preliminary survey of Saudi Arabian Alcyonacea is presented, which combines classical taxonomy, multilocus molecular barcodes, and in situ photographs. We explored 14 locations along the west coast of the Kingdom of Saudi Arabia to assess the regional taxonomic diversity of non-gorgonian alcyonaceans. We collected samples from a total of 74 colonies, distributed among four families: 18 colonies of Alcyoniidae, 14 of Nephtheidae, 9 of Tubiporidae, and 33 of Xeniidae. We sequenced the octocorals using multiple nuclear [ribosomal Internal Transcribed Spacers (ITS) and ATP Synthetase Subunit α (ATPSα)] and mitochondrial [MutS homolog (mtMutS) and Cytochrome C Oxidase subunit one (COI)] loci, providing molecular barcodes which will: (1) allow direct comparison of biodiversity from this location to others for which molecular data are available, and (2) facilitate future identifications of these taxa. Finally, this preliminary phylogeny of sampled taxa provides insights on the resolution of mitochondrial versus nuclear loci, and highlights octocoral taxa that require further taxonomic attention. © 2013 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg.

  13. Taxonomic richness and abundance of cryptic peracarid crustaceans in the Puerto Morelos Reef National Park, Mexico

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    Luz Veronica Monroy-Velázquez

    2017-06-01

    Full Text Available Background and Aims Cryptic peracarids are an important component of the coral reef fauna in terms of diversity and abundance, yet they have been poorly studied. The aim of this study was to evaluate the taxonomic richness and abundance of cryptic peracarids in coral rubble in the Puerto Morelos Reef National Park, Mexico (PMRNP, and their relationship with depth. Methods Three reef sites were selected: (1 Bonanza, (2 Bocana, and (3 Jardines. At each site six kilograms of coral rubble were collected over four sampling periods at three depths: 3 m (back-reef, 6–8 m (fore-reef, and 10–12 m (fore-reef. Results A total of 8,887 peracarid crustaceans belonging to 200 taxa distributed over five orders and 63 families was obtained; 70% of the taxa were identified to species and 25% to genus level. Fifty species of those collected represent new records for the Mexican Caribbean Sea. Isopoda was the most speciose order while Tanaidacea was the most abundant. Discussion Cryptic peracarid taxonomic richness and abundance were related to depth with higher values of both parameters being found in the shallow (3 m back-reef, possibly due to a higher reef development and a greater accumulation of coral rubble produced during hurricanes. Peracarid data obtained in the present study can be used as a baseline for future monitoring programs in the PMRNP.

  14. Taxonomic account of genus Scylla (de Haan, 1833 from Gujarat State, India with two new records of species

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    J. N. Trivedi

    2013-12-01

    Full Text Available The present study describes the taxonomic account of genus Scylla from Gujarat state, India. Specimens of crab were collected from 11 different marine sites/ habitats along the coastal region of the state. Of the several specimens examined on site, 30 morphologically distinct samples were selected for the study, and total 47 different morphological characters were measured. Three different species of genus Scylla were identified viz. Scylla serrata, Scylla tranquebarica and Scylla Olivacea. We report Scylla tranquebarica and Scylla Olivacea for the first time from the state. In general, S. serrata is reported as a dominant species with wide spread distribution while rest of the species show patchy distribution.

  15. A taxonomical review on impact assessment of optimally placed DGs and FACTS controllers in power systems

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    Bindeshwar Singh

    2017-11-01

    Full Text Available In the present scenario of all over the world like develops and undeveloped countries are fastly used Distributed Generations (DGs and Flexible Alternating Current Transmission Systems (FACTS controllers in power systems for reactive power supports so that the overall power system performances are improved such as minimization of real and reactive power losses, environmental pollutions and maximization of loadability of system, power system stability, the short circuit capacity of the line and also enhancement of voltage profile, available power transfer capacity of the system, reliability as well as security of the system and more flexible operations of the system. This survey paper presents a taxonomical review on impact assessment of DGs and FACTS controllers in power systems from different power system performance viewpoints and reveals the current status of research work in this field.

  16. Taxonomic review of Colombian Parodon (Characiformes: Parodontidae, with descriptions of three new species

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    Alejandro Londoño-Burbano

    Full Text Available We review species of Parodon Valenciennes, 1850 from the Magdalena, Cauca, Orinoco, Amazonas, Atrato and Caribbean-Guajira River basins of Colombia using meristic and morphological characters. We recognize eight valid species, five previously described: P. apolinari Myers, from the Orinoco River basin; P. buckleyi Boulenger and P. pongoensis (Allen from the upper Amazon; P. caliensis Boulenger, from the upper Cauca River drainage; and P. suborbitalis Valenciennes, from Lake Maracaibo basin. Three new species are described: P. alfonsoi, from the lower Magdalena River drainage; P. magdalenensis, from the middle Magdalena and upper Cauca River drainages; and P. atratoensis, from the Atrato River basin. We redescribe Parodon suborbitalis using type specimens and topotypes, and designate lectotypes. A taxonomic key is included for identification of the species, as well as geographic distribution maps.

  17. Pigmentary and photonic coloration mechanisms reveal taxonomic relationships of the Cattlehearts (Lepidoptera: Papilionidae: Parides).

    Science.gov (United States)

    Wilts, Bodo D; IJbema, Natasja; Stavenga, Doekele G

    2014-07-27

    The colorful wing patterns of butterflies, a prime example of biodiversity, can change dramatically within closely related species. Wing pattern diversity is specifically present among papilionid butterflies. Whether a correlation between color and the evolution of these butterflies exists so far remained unsolved. We here investigate the Cattlehearts, Parides, a small Neotropical genus of papilionid butterflies with 36 members, the wings of which are marked by distinctly colored patches. By applying various physical techniques, we investigate the coloration toolkit of the wing scales. The wing scales contain two different, wavelength-selective absorbing pigments, causing pigmentary colorations. Scale ridges with multilayered lamellae, lumen multilayers or gyroid photonic crystals in the scale lumen create structural colors that are variously combined with these pigmentary colors. The pigmentary and structural traits strongly correlate with the taxonomical distribution of Parides species. The experimental findings add crucial insight into the evolution of butterfly wing scales and show the importance of morphological parameter mapping for butterfly phylogenetics.

  18. Taxonomic information exchange and copyright: the Plazi approach

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    Egloff Willi

    2009-03-01

    Full Text Available Abstract Background A large part of our knowledge on the world's species is recorded in the corpus of biodiversity literature with well over hundred million pages, and is represented in natural history collections estimated at 2 – 3 billion specimens. But this body of knowledge is almost entirely in paper-print form and is not directly accessible through the Internet. For the digitization of this literature, new territories have to be chartered in the fields of technical, legal and social issues that presently impede its advance. The taxonomic literature seems especially destined for such a transformation. Discussion Plazi was founded as an association with the primary goal of transforming both the printed and, more recently, "born-digital" taxonomic literature into semantically enabled, enhanced documents. This includes the creation of a test body of literature, an XML schema modeling its logic content (TaxonX, the development of a mark-up editor (GoldenGATE allowing also the enhancement of documents with links to external resources via Life Science Identifiers (LSID, a repository for publications and issuance of bibliographic identifiers, a dedicated server to serve the marked up content (the Plazi Search and Retrieval Server, SRS and semantic tools to mine information. Plazi's workflow is designed to respect copyright protection and achieves extraction by observing exceptions and limitations existent in international copyright law. Conclusion The information found in Plazi's databases – taxonomic treatments as well as the metadata of the publications – are in the public domain and can therefore be used for further scientific research without any restriction, whether or not contained in copyrighted publications.

  19. Taxonomic and thematic organisation of proper name conceptual knowledge.

    Science.gov (United States)

    Crutch, Sebastian J; Warrington, Elizabeth K

    2011-01-01

    We report the investigation of the organisation of proper names in two aphasic patients (NBC and FBI). The performance of both patients on spoken word to written word matching tasks was inconsistent, affected by presentation rate and semantic relatedness of the competing responses, all hallmarks of a refractory semantic access dysphasia. In a series of experiments we explored the semantic relatedness effects within their proper name vocabulary, including brand names and person names. First we demonstrated the interaction between very fine grain organisation and personal experience, with one patient with a special interest in the cinema demonstrating higher error rates when identifying the names of actors working in a similar film genre (e.g., action movies: Arnold Schwarzenegger, Bruce Willis, Sylvester Stallone, Mel Gibson) than those working in different genres (e.g., Arnold Schwarzenegger, Gregory Peck, Robin Williams, Gene Kelly). Second we compared directly two potential principles of semantic organisation - taxonomic and thematic. Furthermore we considered these principles of organisation in the context of the individuals' personal knowledge base. We selected topics matching the interests and experience of each patient, namely cinema and literature (NBC) and naval history (FBI). The stimulus items were arranged in taxonomic arrays (e.g., Jane Austen, Emily Bronte, Agatha Christie), thematic arrays (e.g., Jane Austen, Pride and Prejudice, Mr Darcy), and unrelated arrays (e.g., Jane Austen, Wuthering Heights, Hercule Poirot). We documented that different patterns of taxonomic and thematic organisation were constrained by whether the individual has limited knowledge, moderate knowledge or detailed knowledge of a particular vocabulary. It is suggested that moderate proper name knowledge is primarily organised by taxonomy whereas extensive experience results in a more detailed knowledge base in which theme is a powerful organising principle.

  20. Taxonomic and Thematic Organisation of Proper Name Conceptual Knowledge

    Directory of Open Access Journals (Sweden)

    Sebastian J. Crutch

    2011-01-01

    Full Text Available We report the investigation of the organisation of proper names in two aphasic patients (NBC and FBI. The performance of both patients on spoken word to written word matching tasks was inconsistent, affected by presentation rate and semantic relatedness of the competing responses, all hallmarks of a refractory semantic access dysphasia. In a series of experiments we explored the semantic relatedness effects within their proper name vocabulary, including brand names and person names. First we demonstrated the interaction between very fine grain organisation and personal experience, with one patient with a special interest in the cinema demonstrating higher error rates when identifying the names of actors working in a similar film genre (e.g. action movies: Arnold Schwarzenegger, Bruce Willis, Sylvester Stallone, Mel Gibson than those working in different genres (e.g. Arnold Schwarzenegger, Gregory Peck, Robin Williams, Gene Kelly. Second we compared directly two potential principles of semantic organisation – taxonomic and thematic. Furthermore we considered these principles of organisation in the context of the individuals' personal knowledge base. We selected topics matching the interests and experience of each patient, namely cinema and literature (NBC and naval history (FBI. The stimulus items were arranged in taxonomic arrays (e.g. Jane Austen, Emily Bronte, Agatha Christie, thematic arrays (e.g. Jane Austen, Pride and Prejudice, Mr Darcy, and unrelated arrays (e.g. Jane Austen, Wuthering Heights, Hercule Poirot. We documented that different patterns of taxonomic and thematic organisation were constrained by whether the individual has limited knowledge, moderate knowledge or detailed knowledge of a particular vocabulary. It is suggested that moderate proper name knowledge is primarily organised by taxonomy whereas extensive experience results in a more detailed knowledge base in which theme is a powerful organising principle.

  1. Species delimitation in taxonomically difficult fungi: the case of Hymenogaster.

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    Benjamin Stielow

    2011-01-01

    Full Text Available False truffles are ecologically important as mycorrhizal partners of trees and evolutionarily highly interesting as the result of a shift from epigeous mushroom-like to underground fruiting bodies. Since its first description by Vittadini in 1831, inappropriate species concepts in the highly diverse false truffle genus Hymenogaster has led to continued confusion, caused by a large variety of prevailing taxonomical opinions.In this study, we reconsidered the species delimitations in Hymenogaster based on a comprehensive collection of Central European taxa comprising more than 140 fruiting bodies from 20 years of field work. The ITS rDNA sequence dataset was subjected to phylogenetic analysis as well as clustering optimization using OPTSIL software.Among distinct species concepts from the literature used to create reference partitions for clustering optimization, the broadest concept resulted in the highest agreement with the ITS data. Our results indicate a highly variable morphology of H. citrinus and H. griseus, most likely linked to environmental influences on the phenology (maturity, habitat, soil type and growing season. In particular, taxa described in the 19(th century frequently appear as conspecific. Conversely, H. niveus appears as species complex comprising seven cryptic species with almost identical macro- and micromorphology. H. intermedius and H. huthii are described as novel species, each of which with a distinct morphology intermediate between two species complexes. A revised taxonomy for one of the most taxonomically difficult genera of Basidiomycetes is proposed, including an updated identification key. The (semi-automated selection among species concepts used here is of importance for the revision of taxonomically problematic organism groups in general.

  2. [Review on taxonomical studies of Chinese inland-water fish].

    Science.gov (United States)

    Xing, Ying-Chun; Zhao, Ya-Hui; Zhang, Chun-Guang; Yang, Jun-Xing; Tang, Wen-Qiao; Fan, En-Yuan

    2013-08-01

    We reviewed the taxonomy and systematics research history of freshwater fish in China based on 1 236 taxonomic literature records on Chinese freshwater fish. The research was divided into five research periods according to specific historical events: (1) period by foreign scholars, (2) period with Chinese scholars, (3) period during World War II and Civil War, (4) recovery period and (5) period of rapid development. There were representative studies and innovations in all periods. We also discuss here the characteristics of each period on the basis of literature analysis.

  3. Taxonomic Classification for Living Organisms Using Convolutional Neural Networks.

    Science.gov (United States)

    Khawaldeh, Saed; Pervaiz, Usama; Elsharnoby, Mohammed; Alchalabi, Alaa Eddin; Al-Zubi, Nayel

    2017-11-17

    Taxonomic classification has a wide-range of applications such as finding out more about evolutionary history. Compared to the estimated number of organisms that nature harbors, humanity does not have a thorough comprehension of to which specific classes they belong. The classification of living organisms can be done in many machine learning techniques. However, in this study, this is performed using convolutional neural networks. Moreover, a DNA encoding technique is incorporated in the algorithm to increase performance and avoid misclassifications. The algorithm proposed outperformed the state of the art algorithms in terms of accuracy and sensitivity, which illustrates a high potential for using it in many other applications in genome analysis.

  4. Triterpene glycosides of sea cucumbers (Holothuroidea, Echinodermata) as taxonomic markers.

    Science.gov (United States)

    Kalinin, Vladimir I; Avilov, Sergey A; Silchenko, Alexandra S; Stonik, Valentin A

    2015-01-01

    Triterpene glycosides are characteristic metabolites of sea cucumbers (Holothurioidea, Echinodermata). The majority of the glycosides belong to the holostane type {lanostane derivatives with an 18(20)-lactone}. Carbohydrate chains of these glycosides contain xylose, glucose, quinovose, 3-O-methylglucose, and, rarely, 3-O-methylxylose, 3-O-methylglucuronic acid, 3-O-methylquinovose, and 6-O-acetyl-glucose. The glycosides are specific for genera, groups of genera and even for species. The advantages and problems in the use of triterpene glycosides as taxonomic markers in the systematics of sea cucumbers are discussed.

  5. Taxonomic revision of Asian genus Glyptopetalum Thwaites (Celastraceae R. Br.

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    Ivan A. Savinov

    2014-12-01

    Full Text Available Taxonomic survey of Asian genus Glyptopetalum Thwaites (Celastraceae R. Br. is presented. Thirty five species taxa of Glyptopetalum are accepted, including one new species, G.  vidalii I. Savinov (Laos, Thailand, a new record for China, G. tonkinense Pitard (SE Yunnan and a new record for Cambodia,               G. quadrangulare Prain ex King, a new record for Indonesia – G. euonymoides Merr. and a new record for Philippines, Mindanao island – G. loheri Merr. 

  6. Una taxonomía de modelos de desarrollo sustentable

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    Darcy Tetreault

    2004-01-01

    Full Text Available Este ensayo pretende ayudar a desenmarañar una parte del discurso sobre desarrollo sustentable mediante la construcción de una taxonomía de modelos de desarrollo sustentable. La misma taxonomía se basa en una revisión literaria extensiva que en cierta medida privilegia la experiencia mexicana. De este modo, el ensayo presenta y compara tanto modelos normativos como positivos. Los modelos incluidos son el modelo dominante, el cual corresponde con la estrategia esbozada en el Informe Bruntland y Agenda 21; la ecología política, un modelo desarrollado por el economista francés Alain Lipietz; el modelo comunitario de desarrollo sustentable, cuyas raíces se encuentran en una escuela de pensamiento de la década de los setenta conocida como el “otro desarrollo”; el comercio justo, una experiencia cuyas raíces se encuentran en las comunidades indígenas de Oaxaca; la producción forestal industrial comunitaria, que ha sido puesta en práctica por varias comunidades forestales en el sur y el centro del país; el activismo ambiental, sobre todo respecto a los con- fl ictos locales que giran en torno al control de los recursos naturales; y la conservación basada en la comunidad, cuya manifestación principal es la reserva de la biosfera

  7. Variance Component Selection With Applications to Microbiome Taxonomic Data

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    Jing Zhai

    2018-03-01

    Full Text Available High-throughput sequencing technology has enabled population-based studies of the role of the human microbiome in disease etiology and exposure response. Microbiome data are summarized as counts or composition of the bacterial taxa at different taxonomic levels. An important problem is to identify the bacterial taxa that are associated with a response. One method is to test the association of specific taxon with phenotypes in a linear mixed effect model, which incorporates phylogenetic information among bacterial communities. Another type of approaches consider all taxa in a joint model and achieves selection via penalization method, which ignores phylogenetic information. In this paper, we consider regression analysis by treating bacterial taxa at different level as multiple random effects. For each taxon, a kernel matrix is calculated based on distance measures in the phylogenetic tree and acts as one variance component in the joint model. Then taxonomic selection is achieved by the lasso (least absolute shrinkage and selection operator penalty on variance components. Our method integrates biological information into the variable selection problem and greatly improves selection accuracies. Simulation studies demonstrate the superiority of our methods versus existing methods, for example, group-lasso. Finally, we apply our method to a longitudinal microbiome study of Human Immunodeficiency Virus (HIV infected patients. We implement our method using the high performance computing language Julia. Software and detailed documentation are freely available at https://github.com/JingZhai63/VCselection.

  8. A numerical phenotypic taxonomic study of the genus Neisseria.

    Science.gov (United States)

    Barrett, S J; Sneath, P H

    1994-10-01

    A numerical phenotypic taxonomic study of 315 strains of Neisseria and some allied bacteria examined for 155 phenotypic tests showed 31 groups, most of which were reasonably distinct. These fell into four major areas. Areas A, B and C contained species of Neisseria, whereas area D contained the organisms known as 'false neisserias' together with Branhamella, Moraxella and Kingella species. Area A contained N. gonorrhoeae (which showed two subgroups), N. meningitidis (with two subgroups, and N. cinerea closely associated), N. polysaccharea, N. elongata subsp, glycolytica and N. lactamica. Area B contained mainly organisms from the human nasopharynx, and the nine groups were not very distinct: only three, N. mucosa, N. perflava and N. sicca could be recognized by the presence of type strains, and there was little relationship between taxonomic position and species epithets. Area C contained several groups from animals, N. animalis, N. canis and two phenons that may be justified as new species of Neisseria, one from lizards and the other from dental plaque of herbivores. Area C also contained N. elongata, N. subflava (with N. flavescens), type strain of Morococcus cerebrosis and the CDC groups M-5 (N. weaveri) and EF-4. Area D contained Branhamella catarrhalis, a combined group which consists of strains of the 'false neisserias' N. caviae and N. cuniculi, the 'false neisseria' N. ovis, and a group of Moraxella strains. A small group representing Kingella kingae is included in area D. Mean test error was 1.7%.

  9. The taxonomic foundation, species circumscription and continental endemisms of Singerocybe: evidence from morphological and molecular data.

    Science.gov (United States)

    Qin, Jiao; Feng, Bang; Yang, Zhu L; Li, Yan-Chun; Ratkowsky, David; Gates, Genevieve; Takahashi, Haruki; Rexer, Karl-Heinz; Kost, Gerhard W; Karunarathna, Samantha C

    2014-01-01

    The genus Singerocybe (Tricholomataceae, Agaricales, Basidiomycota) has been the subject of controversy since its proposal in 1988. Its taxonomic foundation, species circumscription and geographical distribution have not yet been examined with molecular sequence data. In this study phylogenetic analyses on this group of fungi were conducted based on collections from Europe, eastern Asia, southern Asia, North America and Australia, with four nuclear markers, ITS, nrLSU, tef1-α and rpb2. Molecular phylogenetic analyses, together with morphological observations, strongly support Singerocybe as a monophyletic group and identify the vesicles in the pileal and stipe cuticle as a synapomorphy of this genus. Seven species are recognized in the genus, including one new species and four new combinations. Clitocybe trogioides and Clitocybe trogioides var. odorifera are synonyms of Singerocybe humilis and Singerocybe alboinfundibuliformis respectively. Most of these species are geographically restricted in their distributions. Furthermore our study expands the distribution range of Singerocybe from the North Temperate Zone to Australia (Tasmania) and tropical southern Asia. © 2014 by The Mycological Society of America.

  10. A taxonomic study of Albizia (Leguminosae: Mimosoideae: Ingeae in Mexico and Central America

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    Rico Arce, María de Lourdes

    2008-12-01

    Full Text Available The genus Albizia is economically and environmentally important because many elements are multipurpose trees. A taxonomic study of 12 Central American and Mexican Albizia species is presented. Identification keys, illustrations and ecological information are provided together with some taxonomic comments. Distribution maps and conservation status are given for each native species in the area. Three epithets are lectotypyfied and three new name combinations are made. An interactive identification electronic key is available from the authors if requested. Full specimen records are available at www.kew.org/herbcat .El género Albizia tiene importancia económica y ecológica porque en su mayoría está integrado por árboles con usos múltiples. Se presenta un estudio taxonómico para 12 especies con distribución en México y Centro América, se incluyen claves para la identificación de las especies, ilustraciones, mapas de distribución, estados de conservación de las especies nativas del área y comentarios ecológicos y taxonómicos. Se formaliza la lectipificacion de tres epítetos y se proponen tres nuevas combinaciones. Una clave electrónica interactiva para la identificación de las especies se puede solicitar a los autores. Finalmente el conjunto completo de los ejemplares de herbario puede ser consultado en el sitio Web de los Jardines Reales de Kew: www.kew.org/herbcat.

  11. Estudos taxonômicos em Philacra Dwyer (Ochnaceae = Taxonomic studies on Philacra Dwyer (Ochnaceae

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    Fabíola Feres

    2006-07-01

    Full Text Available As espécies de Philacra são encontradas principalmente na fronteira Brasil-Venezuela, e dentre outros gêneros de Ochnaceae, é o mais próximo a Luxemburgia, cujas espécies ocorrem somente no Brasil, especialmente na Cadeia do Espinhaço. A análise taxonômica das espécies de Philacra foi realizada com base no material tipo e em espécimes depositados em herbários. O trabalho objetivou a redescrição do gênero, a elaboração da chave taxonômica e a redescrição das espécies. É apresentada a redescrição do gênero, suadistribuição geográfica, a chave de identificação e a redescrição das espécies. Atualmente, são reconhecidas quatro espécies de Philacra: P. auriculata Dwyer, P. duidae (Gleason Dwyer, P. longifolia (Gleason Dwyer e, P. steyermarkii Maguire.The species of Philacra are found mainly at the Brazil-Venezuela border. Among other Ochnaceae genera, this is the most closely related to Luxemburgia, which occurs only in Brazil, especially at theEspinhaço Range. The taxonomic analysis of Philacra species was based on the type material and herbarium specimens. This work aimed to redescribe the genus, to prepare a taxonomic key and to redescribe the species. The genus redescription and the geographical distribution, a key to the species and species redescription, are presented. Currently, four Philacra species are recognized: P. auriculata Dwyer, P. duidae (Gleason Dwyer, P. longifolia (Gleason Dwyer, and P. steyermarkii Maguire.

  12. XML schemas and mark-up practices of taxonomic literature.

    Science.gov (United States)

    Penev, Lyubomir; Lyal, Christopher Hc; Weitzman, Anna; Morse, David R; King, David; Sautter, Guido; Georgiev, Teodor; Morris, Robert A; Catapano, Terry; Agosti, Donat

    2011-01-01

    We review the three most widely used XML schemas used to mark-up taxonomic texts, TaxonX, TaxPub and taXMLit. These are described from the viewpoint of their development history, current status, implementation, and use cases. The concept of "taxon treatment" from the viewpoint of taxonomy mark-up into XML is discussed. TaxonX and taXMLit are primarily designed for legacy literature, the former being more lightweight and with a focus on recovery of taxon treatments, the latter providing a much more detailed set of tags to facilitate data extraction and analysis. TaxPub is an extension of the National Library of Medicine Document Type Definition (NLM DTD) for taxonomy focussed on layout and recovery and, as such, is best suited for mark-up of new publications and their archiving in PubMedCentral. All three schemas have their advantages and shortcomings and can be used for different purposes.

  13. Effects of land use on taxonomic and functional diversity

    DEFF Research Database (Denmark)

    Hevia, Violeta; Carmona, Carlos P.; Azcárate, Francisco M.

    2016-01-01

    Land-use change is the major driver of biodiversity loss. However, taxonomic diversity (TD) and functional diversity (FD) might respond differently to land-use change, and this response might also vary depending on the biotic group being analysed. In this study, we compare the TD and FD of four......: the sampling unit scale and the site scale. Land-use intensity effects on TD and FD were quite different and highly varied among the four biotic groups, with no single clear pattern emerging that could be considered general for all organisms. Additive partitioning of species diversity revealed clear...... contrasting patterns between TD and FD in the percentage of variability observed at each spatial scale. While most variability in TD was found at the larger scales, irregardless of organism group and land-use type, most variability in FD was found at the smallest scale, indicating that species turnover among...

  14. Taxonomic investigations of bacteriophage sensitive bacteria isolated from marine waters

    Science.gov (United States)

    Moebus, K.; Nattkemper, H.

    1983-12-01

    Based on 28 criteria the taxonomy of 366 phage sensitive bacterial strains isolated from marine waters (Atlantic between European continental shelf and Sargasso Sea, Bay of Biscay, North Sea near Helgoland) was investigated. Seventy-eight phage-intensity strains derived from the same Atlantic Ocean regions as the sensitive ones were tested for comparison. While in the latter considerable diversity was observed, the results obtained with the phage-sensitive bacteria are characterized by stupendous uniformity. 362 of the 366 strains are assigned to the family Vibrionaceae, some 280 of which belong to the genus Vibrio. As discussed, this taxonomic uniformity among the phage-sensitive bacteria is assumed to be an artifact mainly caused by the type of enrichment culture employed for the isolation of all but a few bacteriophage strains used and, to a lesser degree, by characteristics of the bacterial populations encountered.

  15. Memory systems, processes, and tasks: taxonomic clarification via factor analysis.

    Science.gov (United States)

    Bruss, Peter J; Mitchell, David B

    2009-01-01

    The nature of various memory systems was examined using factor analysis. We reanalyzed data from 11 memory tasks previously reported in Mitchell and Bruss (2003). Four well-defined factors emerged, closely resembling episodic and semantic memory and conceptual and perceptual implicit memory, in line with both memory systems and transfer-appropriate processing accounts. To explore taxonomic issues, we ran separate analyses on the implicit tasks. Using a cross-format manipulation (pictures vs. words), we identified 3 prototypical tasks. Word fragment completion and picture fragment identification tasks were "factor pure," tapping perceptual processes uniquely. Category exemplar generation revealed its conceptual nature, yielding both cross-format priming and a picture superiority effect. In contrast, word stem completion and picture naming were more complex, revealing attributes of both processes.

  16. Flora of the city of Podgorica, Montenegro: Taxonomic analysis

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    Stešević Danijela

    2008-01-01

    Full Text Available In this paper we present the taxonomic segment of a floristic study undertaken in the city of Podgorica in the period of 2002-2007. The check-list of spontaneously growing vascular plants includes 1227 species and subspecies belonging to 545 genera and 118 families. The dominant families are Poaceae (11.7%, asteraceae (11.2% and Fabaceae (9.2%. The most abundant genera are Trifolium (2.1%, Euphorbia (1.5%, Carex (1.5%, Bromus (1.3% and Vicia (1.2%. Analysis of the flora of Podgorica in comparison with some other european cities showed that the flora of Podgorica is most similar to that of Rome (Q/S= 0,7.

  17. Taxonomic Classification for Living Organisms Using Convolutional Neural Networks

    Directory of Open Access Journals (Sweden)

    Saed Khawaldeh

    2017-11-01

    Full Text Available Taxonomic classification has a wide-range of applications such as finding out more about evolutionary history. Compared to the estimated number of organisms that nature harbors, humanity does not have a thorough comprehension of to which specific classes they belong. The classification of living organisms can be done in many machine learning techniques. However, in this study, this is performed using convolutional neural networks. Moreover, a DNA encoding technique is incorporated in the algorithm to increase performance and avoid misclassifications. The algorithm proposed outperformed the state of the art algorithms in terms of accuracy and sensitivity, which illustrates a high potential for using it in many other applications in genome analysis.

  18. Taxonomic status of two morphotypes of Coryphaena hippurus (Perciformes: Coryphaenidae

    Directory of Open Access Journals (Sweden)

    Alan Bonner

    2017-03-01

    Full Text Available ABSTRACT Two Coryphaena hippurus morphotypes (dourado and palombeta are found along the Brazilian coast and are considered by Rio de Janeiro’s fisherman and fishmongers as two different species. Furthermore, these morphotypes are commercialized under different values and suffer different fishing pressure. Therefore, a definition of their taxonomic status is an important economic and biological matter. In order to investigate this problem, allozyme electrophoresis method was undertaken for seventeen loci on 117 individuals of C. hippurus sampled at Cabo Frio/RJ (Brazil. The data indicate homogeneity between the morphotypes gene pools. Nevertheless, differences were found for genetic variation among dourado and palombeta, especially due to alcohol dehydrogenase locus. Natural selection hypothesis is discussed in explaining these findings.

  19. Seed morphology and its taxonomic significance in the family malvaceae

    International Nuclear Information System (INIS)

    Abid, R.; Ather, A.

    2016-01-01

    The seed morphological studies of 75 taxa belonging to 6 sub-families of the family Malvaceae were carried out from Pakistan. In Pakistan the family Malvaceae is represented by 6 sub-families viz., Byttnerioideae, Dombeyoideae, Malvoideae, Bombacoideae, Helicteroideae and Sterculioideae. The seed macro and micro morphological characters are examined, using light (LM) and scanning electron microscopy (SEM). Detailed seed morphological descriptions, micrographs and keys based on seed characters are also provided. A variety in various quantitative and qualitative seed characters was observed. The micro-morphological characters of seeds are quite significant to strengthen the taxonomic decisions within the family Malvaceae at various levels. The data obtained from the seed morphological characters were analyzed numerically to trace out the phylogenetic affinities for the taxa within the family Malvaceae from Pakistan. (author)

  20. Fossil struthionid eggshells from Laetoli, Tanzania: Taxonomic and biostratigraphic significance

    Science.gov (United States)

    Harrison, Terry; Msuya, Charles P.

    2005-04-01

    Recent paleontological investigations at Laetoli and neighboring localities in northern Tanzania have produced a large collection of fossil ostrich eggshells from the Pliocene-aged Laetolil Beds (˜3.5-4.5 Ma) and Ndolanya Beds (˜2.6-2.7 Ma). A detailed analysis of the morphology of the eggshells and their taxonomic affinities indicates that two different species of Struthio are represented. In the Lower Laetolil Beds and in the Upper Laetolil Beds below Tuff 3 a new species is recognized— Struthio kakesiensis. This is replaced in the Upper Laetolil Beds by Struthio camelus, the modern species of ostrich. Since radiometric age determinations are available for the stratigraphic sequence at Laetoli, it is possible to precisely date the first appearance of S. camelus at ˜3.6-3.8 Ma. Comparisons of the Laetoli material with specimens from the well-dated sequences at Lothagam and Kanapoi in northern Kenya, allow the taxonomic and biochronological analysis to be extended back in time to the late Miocene. At about 6.5 Ma, Diamantornis and elephant birds were replaced in East Africa by ostriches belonging to the genus Struthio. Three time-successive species of ostriches are identified in the fossil record of East Africa, beginning with Struthio. cf. karingarabensis (˜6.5-4.2 Ma), followed by S. kakesiensis (˜4.5-3.6 Ma) and then S. camelus (˜3.8 Ma onwards). A similar sequence of taxa has previously been recorded from localities in Namibia, but at these sites there is no possibility to precisely calibrate the ages of the different species using radiometric dating. Nevertheless, the broadly similar evolutionary sequence and the close correspondence in inferred ages for the succession of species in East Africa and Namibia suggest that ostrich eggshells are a very useful tool for biochronological correlation of paleontological sites in sub-Saharan Africa.

  1. Is Homo sapiens polytypic? Human taxonomic diversity and its implications.

    Science.gov (United States)

    Woodley, Michael A

    2010-01-01

    The term race is a traditional synonym for subspecies, however it is frequently asserted that Homo sapiens is monotypic and that what are termed races are nothing more than biological illusions. In this manuscript a case is made for the hypothesis that H. sapiens is polytypic, and in this way is no different from other species exhibiting similar levels of genetic and morphological diversity. First it is demonstrated that the four major definitions of race/subspecies can be shown to be synonymous within the context of the framework of race as a correlation structure of traits. Next the issue of taxonomic classification is considered where it is demonstrated that H. sapiens possesses high levels morphological diversity, genetic heterozygosity and differentiation (F(ST)) compared to many species that are acknowledged to be polytypic with respect to subspecies. Racial variation is then evaluated in light of the phylogenetic species concept, where it is suggested that the least inclusive monophyletic units exist below the level of species within H. sapiens indicating the existence of a number of potential human phylogenetic species; and the biological species concept, where it is determined that racial variation is too small to represent differentiation at the level of biological species. Finally the implications of this are discussed in the context of anthropology where an accurate picture of the sequence and timing of events during the evolution of human taxa are required for a complete picture of human evolution, and medicine, where a greater appreciation of the role played by human taxonomic differences in disease susceptibility and treatment responsiveness will save lives in the future.

  2. Taxonomic composition of phytoplankton in the Vakh River (Western Siberia)

    Science.gov (United States)

    Skorobogatova, O. N.

    2018-03-01

    This paper provides data on the hydrological and hydrochemical parameters of the Vakh River in the Middle Ob region. In 2005-2008 we have identified 404 taxonomic units represented by 463 species, types and forms of algae, belonging to 140 genera, 52 families, 13 classes and 7 divisions. 386 species were identified for the first time, 141 taxa were identified as rare and 22 taxa as new for Western Siberia. Leading divisions, Bacillariophyta and Chlorophyta, make up for 78.9% of total phytoplankton diversity. Cyanobacteria, Chrysophyta and Euglenophyta form a community of 88 taxonomic units having a rank lower than genus level, and represent 19.0% of the total number. The floral role of Xanthophyta and Dinophyta is insignificant (2.1%). The main structure-forming species are 14: vegetating throughout the year (Aulacoseira italica, Asterionella formosa), summer taxa (Microcystis aeruginosa, Melosira varians, Aulacoseira granulata, Pandorina morum, Pediastrum boryanum, P. duplex, Lacunastrum gracillimum, Scenedesmus quadricauda) and summer-autumn (Microcystis pulverea, Tabellaria fenestrata, T. flocculosa, Mucidosphaerium pulchellum). The Vakh River demonstrates specific characteristics of boreal flowing waterways. The northern composition is represented in a big rate of families (44.2%) and genera (109 77.9) with one to three species. The richest genera Closterium (31 taxa), Eunotia (27 taxa), Pinnularia (22 taxa), Desmidium (11 taxa) and the family Desmidiaceae (45 taxa) ensure diversity of phytoplankton. Ecological and geographical analysis demonstrates predominance of cosmopolitan algae (56.6%). Plankton represents 44.7% of all algae, oligogalobs - 78.8% and indifferent algae – 36.7%. Water meets the requirements for β-mezosaprobian pollution zone, class of satisfactory purity (III class).

  3. Review: Taxonomic Contribution For Ecotourism Development In Indonesia

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    Nurul Chairiyah

    2013-09-01

    Full Text Available This paper describes about the role of taxonomic in ecotourism development in Indonesia. Development and management of ecotourism in Indonesia recently are still quite slow and inadequate. It is due to the lack of knowledge of local community about the information of flora and fauna which is used as ecotourism attraction. Therefore the taxonomical science needs to be applied to the development of ecotourism in Indonesia. In addition, some species which are used as tourist attractions needs to be identified and classified to preserve the resource. Implementation of taxonomy related to survey, documentation, data collection, identification and classification to establish the identity of a species for ecotourism attraction. Methods are commonly used for the implementation of taxonomy in the ecotourism development, i.e. (1 morphological observation, (2 vocalizations and (3 molecular analysis. Morphological observations can be applied by qualitative and quantitative observations. Qualitative observation is an observation of a species, which is related to morphology and coloration, and comparison with other species which are suspected related. Quantitative observation is a morphometric analysis, which is a concept of quantitative analysis of the species that related to the size and shape of a species. Vocalization method is applied by determining the vocal character of a species, by comparing the data, which has obtained, with the data vocals from other species which are suspected related. Molecular analysis is commonly used to support the identification of morphological and vocalization of the species. Molecular methods, which are commonly applied for species identification, are usually hybridization, DNA sequencing, restriction mapping, chromosome banding and immunological method Keywords: taxonomy, ecotourism, Indonesia, morphological observation, vocalization, molecular identification

  4. Lago Maggiore oligotrophication as seen from the long-term evolution of its phytoplankton taxonomic size structure

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    Giuseppe MORABITO

    2009-02-01

    Full Text Available Due to the rapid and common deterioration of aquatic ecosystems, scientists and environmental protection organizations acutely need means capable of producing quantitative estimates for structural deformations of natural communities. Recently, very common biomass size spectra ignore community taxonomic composition, i.e., one of the most important kinds of biological information. Therefore, another very old, but rare in planktonology, method – the traditional taxonomic size spectrum (TTSS – can be helpful. TTSS, a specific form of size-frequency distribution of taxonomic units, reveals repeating patterns of deep subalpine Lago Maggiore (Italy phytoplankton taxonomic structure. The general TTSS pattern was safeguarded during 22 annual cycles (1984-2005, when many principal environmental characteristics were changed considerably during the lake oligotrophication. At the same time, the fine structure deformations of this pattern helped us divide the total oligotrophication process into several stages characterized by notable changes of TTSS peaks' proportions. These peak-height alterations were caused by pronounced changes in the species list and overall taxonomic diversity of the lake phytoplankton. The average cell volume decline was found. It was significantly correlated with the total phosphorus descending trend. This cell volume decline was produced by the addition of numerous species into the medium-and-small size fractions. Typical patterns of the stable and transitory stages were differentiated, which could be valuable for environmental protection and diagnostic applications. The central peak height difference between the stable and the transitory periods was statistically significant. Oligotrophication process decomposition into several more homogenous groups of years was supported by quantitative estimators produced by hierarchical cluster analysis. The highest level of the similarity measure (Pearson r in pairs of annual TTSS was

  5. Evolution of microgastropods (Ellobioidea, Carychiidae): integrating taxonomic, phylogenetic and evolutionary hypotheses

    Science.gov (United States)

    2013-01-01

    Background Current biodiversity patterns are considered largely the result of past climatic and tectonic changes. In an integrative approach, we combine taxonomic and phylogenetic hypotheses to analyze temporal and geographic diversification of epigean (Carychium) and subterranean (Zospeum) evolutionary lineages in Carychiidae (Eupulmonata, Ellobioidea). We explicitly test three hypotheses: 1) morphospecies encompass unrecognized evolutionary lineages, 2) limited dispersal results in a close genetic relationship of geographical proximally distributed taxa and 3) major climatic and tectonic events had an impact on lineage diversification within Carychiidae. Results Initial morphospecies assignments were investigated by different molecular delimitation approaches (threshold, ABGD, GMYC and SP). Despite a conservative delimitation strategy, carychiid morphospecies comprise a great number of unrecognized evolutionary lineages. We attribute this phenomenon to historic underestimation of morphological stasis and phenotypic variability amongst lineages. The first molecular phylogenetic hypothesis for the Carychiidae (based on COI, 16S and H3) reveals Carychium and Zospeum to be reciprocally monophyletic. Geographical proximally distributed lineages are often closely related. The temporal diversification of Carychiidae is best described by a constant rate model of diversification. The evolution of Carychiidae is characterized by relatively few (long distance) colonization events. We find support for an Asian origin of Carychium. Zospeum may have arrived in Europe before extant members of Carychium. Distantly related Carychium clades inhabit a wide spectrum of the available bioclimatic niche and demonstrate considerable niche overlap. Conclusions Carychiid taxonomy is in dire need of revision. An inferred wide distribution and variable phenotype suggest underestimated diversity in Zospeum. Several Carychium morphospecies are results of past taxonomic lumping. By collecting

  6. Using hand proportions to test taxonomic boundaries within the Tupaia glis species complex (Scandentia, Tupaiidae)

    Science.gov (United States)

    Sargos, Eric J.; Woodman, Neal; Reese, Aspen T.; Olson, Link E.

    2013-01-01

    Treeshrews (order Scandentia) comprise 2 families of squirrel-sized terrestrial, arboreal, and scansorial mammals distributed throughout much of tropical South and Southeast Asia. The last comprehensive taxonomic revision of treeshrews was published in 1913, and a well-supported phylogeny clarifying relationships among all currently recognized extant species within the order has only recently been published. Within the family Tupaiidae, 2 widely distributed species, the northern treeshrew, Tupaia belangeri (Wagner, 1841), and the common treeshrew, T. glis (Diard, 1820), represent a particularly vexing taxonomic complex. These 2 species are currently distinguished primarily based on their respective distributions north and south of the Isthmus of Kra on the Malay Peninsula and on their different mammae counts. This problematic species complex includes 54 published synonyms, many of which represent putative island endemics. The widespread T. glis and T. belangeri collectively comprise a monophyletic assemblage representing the sister lineage to a clade composed of the golden-bellied treeshrew, T. chrysogaster Miller, 1903 (Mentawai Islands), and the long-footed treeshrew, T. longipes (Thomas, 1893) (Borneo). As part of a morphological investigation of the T. glis–T. belangeri complex, we studied the proportions of hand bones, which have previously been shown to be useful in discriminating species of soricids (true shrews). We measured 38 variables from digital X-ray images of 148 museum study skins representing several subspecies of T. glis, T. belangeri, T. chrysogaster, and T. longipes and analyzed these data using principal components and cluster analyses. Manus proportions among these 4 species readily distinguish them, particularly in the cases of T. chrysogaster and T. longipes. We then tested the distinctiveness of several of the populations comprising T. glis and T. longipes. T. longipes longipes and T. l. salatana Lyon, 1913, are distinguishable from each

  7. Reproductive strategies, karyology, parasites, and taxonomic status of Dugesia populations from Yemen (Platyhelminthes: Tricladida: Dugesiidae).

    Science.gov (United States)

    Harrath, Abdul Halim; Sluys, Ronald; Aldahmash, Waleed; Al-Razaki, Abdulkarim; Alwasel, Saleh

    2013-06-01

    We present new data on the distribution, reproductive strategies, karyology, and taxonomic status of populations of freshwater planarians from Yemen. Nine populations were sampled and significant differences in their reproductive strategies and karyology are reported. The present study presents the first fully documented record of a naturally sexual, diploid (2n = 18) population of a Dugesia species in the eastern part of the Afrotropical region. Morphological characters combined with karyological data suggest that these Dugesia populations from Yemen represent a new species, which is herein described as Dugesia arabica Harrath and Sluys, sp. nov. This new species is mainly distinguishable from other Dugesia species that are distributed exclusively in the Mediterranean basin and in the eastern part of the Afrotropical region by the presence of the following features: well-developed and cone-shaped penis papilla, housing an ejaculatory duct that runs ventrally and has a subterminal and ventral opening; a considerably expanded and folded section of the bursal canal at the level of the oviducal openings; absence of a layer of longitudinal muscles on the copulatory bursa and the bursal canal. Specimens from two populations from Yemen were infested with a gregarine Protozoon.

  8. Proteogenomics of rare taxonomic phyla: A prospective treasure trove of protein coding genes.

    Science.gov (United States)

    Kumar, Dhirendra; Mondal, Anupam Kumar; Kutum, Rintu; Dash, Debasis

    2016-01-01

    Sustainable innovations in sequencing technologies have resulted in a torrent of microbial genome sequencing projects. However, the prokaryotic genomes sequenced so far are unequally distributed along their phylogenetic tree; few phyla contain the majority, the rest only a few representatives. Accurate genome annotation lags far behind genome sequencing. While automated computational prediction, aided by comparative genomics, remains a popular choice for genome annotation, substantial fraction of these annotations are erroneous. Proteogenomics utilizes protein level experimental observations to annotate protein coding genes on a genome wide scale. Benefits of proteogenomics include discovery and correction of gene annotations regardless of their phylogenetic conservation. This not only allows detection of common, conserved proteins but also the discovery of protein products of rare genes that may be horizontally transferred or taxonomy specific. Chances of encountering such genes are more in rare phyla that comprise a small number of complete genome sequences. We collated all bacterial and archaeal proteogenomic studies carried out to date and reviewed them in the context of genome sequencing projects. Here, we present a comprehensive list of microbial proteogenomic studies, their taxonomic distribution, and also urge for targeted proteogenomics of underexplored taxa to build an extensive reference of protein coding genes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Polysemy and the Taxonomic Constraint: Children's Representation of Words That Label Multiple Kinds

    Science.gov (United States)

    Srinivasan, Mahesh; Snedeker, Jesse

    2014-01-01

    How do children resolve the problem of indeterminacy when learning a new word? By one account, children adopt a "taxonomic assumption" and expect the word to denote only members of a particular taxonomic category. According to one version of this constraint, young children should represent polysemous words that label multiple kinds--for…

  10. Taxonomic status of the roses (Rosa) described by S.G. Dimitrov from Bulgaria

    DEFF Research Database (Denmark)

    Zielinski, J.; Petrova, A; Tan, Kit

    2004-01-01

    The original herbarium vouchers for six species of Rosa (Rosaceae) described by S. G. Dimitrov from Bulgaria are taxonomically evaluated. Two species (R. balcanica, R. orphei) are considered hybrids, four other names (R. bulgarica, R. parilica, R. pontica and R. rhodopaea) are taxonomic synonyms...

  11. Taxonomic delimitation and drivers of speciation in the Ibero-North African Carex sect. Phacocystis river-shore group (Cyperaceae).

    Science.gov (United States)

    Jiménez-Mejías, Pedro; Escudero, Marcial; Guerra-Cárdenas, Samuel; Lye, Kåre A; Luceño, Modesto

    2011-11-01

    The Ibero-North African Carex sect. Phacocystis river-shore group is a set of perennial helophytic species with poorly defined taxonomic boundaries. In the present study, we delimited the different taxonomic units, addressed the phylogeographic history, and evaluated the drivers of differentiation that have promoted diversification of these plants. We analyzed molecular data using statistical parsimony for plastid sequences (26 samples from 26 populations) and principal coordinate analysis, neighbor joining, and Bayesian analysis of population structure for AFLPs (186 samples from 26 populations). Chromosome numbers from 14 samples (9 populations) are newly reported. Three species can be distinguished (C. acuta, C. elata, and C. reuteriana). Unexpectedly for rhizome-growing helophytes, the vegetative reproduction detected was incidental. The widespread C. elata was found to be a genetically poorly differentiated taxon, whereas the local C. reuteriana displayed geographical structuring. Geographical factors seem to be the main driver of differentiation for both taxa. Despite apparent morphological and ecological similarities, C. elata and C. reuteriana have disparate genetic structures and evolutionary histories, which may have originated from small ecological differences. Carex elata is broadly distributed throughout Europe, and its northern populations were recently founded, probably after the last glacial maximum. In contrast, C. reuteriana is an Ibero-North African endemic, with long-standing populations affected by isolation and limited gene flow. It is likely that high-density blocking effects and different gene-flow barriers act together to delimit its distribution and promote its relatively high population differentiation.

  12. Taxonomic reassessment of two subspecies of Chinese skink in Taiwan based on morphological and molecular investigations (Squamata, Scincidae).

    Science.gov (United States)

    Kurita, Kazuki; Nakamura, Yukiko; Okamoto, Taku; Lin, Si-Min; Hikida, Tsutomu

    2017-01-01

    The Chinese skink, Plestiodon chinensis (Gray, 1838), is widely distributed across continental China, Taiwan, the Korean Peninsula, and offshore islets, and consists of several subspecies. Here morphological and molecular methods have been used to reassess the taxonomic status and distributions of P. c. formosensis (Van Denburgh, 1912) and P. c. leucostictus (Hikida, 1988), which are endemic to Taiwan and Green Island (an islet off the east coast of Taiwan), respectively. It can be confirmed that the eastern Taiwanese populations of P. c. formosensis exhibit similar juvenile color patterning and genetic composition to the islet subspecies P. c. leucostictus , and are distinct from consubspecific populations in western Taiwan. Therefore, the eastern Taiwanese populations are assigned to P. c. leucostictus , and this subspecies is recognized as a distinct species, Plestiodon leucostictus (Hikida, 1988), based on their unique juvenile coloration and highly divergent DNA sequences. Our results also revealed that P. c. formosensis in western Taiwan is close to nominotypical subspecies from the continent, suggesting the necessity of a comprehensive taxonomic analysis in the future.

  13. Nuclear genome size and genomic distribution of ribosomal DNA in Musa and Ensete (Musaceae): taxonomic implications

    Czech Academy of Sciences Publication Activity Database

    Bartoš, Jan; Alkhimova, Olena; Kubaláková, Marie; De Langhe, E.; Doležel, Jaroslav

    2005-01-01

    Roč. 109, - (2005), s. 50-57 ISSN 1424-8581 R&D Projects: GA AV ČR IAA6038204 Grant - others:IAEA Research Contract 12230/RBF Institutional research plan: CEZ:AV0Z50380511 Keywords : Musa and Ensete * nuclear genome size * FISH Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.076, year: 2005

  14. Taxonomic relationships among Phenacomys voles as inferred by cytochrome b

    Science.gov (United States)

    Bellinger, M.R.; Haig, S.M.; Forsman, E.D.; Mullins, T.D.

    2005-01-01

    Taxonomic relationships among red tree voles (Phenacomys longicaudus longicaudus, P. l. silvicola), the Sonoma tree vole (P. pomo), the white-footed vole (P. albipes), and the heather vole (P. intermedius) were examined using 664 base pairs of the mitochondrial cytochrome b gene. Results indicate specific differences among red tree voles, Sonoma tree voles, white-footed voles, and heather voles, but no clear difference between the 2 Oregon subspecies of red tree voles (P. l. longicaudus and P. l. silvicola). Our data further indicated a close relationship between tree voles and albipes, validating inclusion of albipes in the subgenus Arborimus. These 3 congeners shared a closer relationship to P. intermedius than to other arvicolids. A moderate association between porno and albipes was indicated by maximum parsimony and neighbor-joining phylogenetic analyses. Molecular clock estimates suggest a Pleistocene radiation of the Arborimus clade, which is concordant with pulses of diversification observed in other murid rodents. The generic rank of Arborimus is subject to interpretation of data.

  15. Taxonomic reappraisal of Antithamnion sparsum Tokida (Ceramiaceae, Rhodophyta).

    Science.gov (United States)

    Kim, Gwang Hoon; Han, He Kyong; Lim, Kook Jin

    2008-07-01

    The taxonomic criterion of Antithamnion sparsum was reappraised in comparison with A. densum and A. defectum based on crossing experiments, morphological observation, chromosome study and Random Amplified Polymorphic DNA (RAPD) analysis. These species had a very similar morphology but were sexually isolated. The chromosome number was n = ca. 24 for A. densum, n = ca. 21 for A. defectum, and n = ca. 44 for A. sparsum. All isolates of A. sparsum and A. densum showed polysiphonia-type life history Asexual reproduction was induced by favorable environmental conditions. In A. sparsum, 1-2% of male plants developed mitotic tetrasporangia together with spermatangia. In A. densum, 5-10% of tetraspores developed into asexual tetrasporophytes. Phylogenetic relationships between these species were examined using RAPD analysis, and A. glanduliferum was used as an outgroup. A total of 167 polymorphic RAPD markers amplified from 15 different primers were analyzed. Results suggested that these species were closely related, with A. defectum placed in the middle of A. sparsum and A. densum. Chromosome study and RAPD analysis implied that A. sparsum first separated from A. defectum through polyploidization and later A. densum evolved. These species may present another example of the narrow species concept in the genus Antithamnion.

  16. Recent progress in floristic and taxonomic studies in Bulgaria

    Directory of Open Access Journals (Sweden)

    Ana Petrova

    2018-02-01

    Full Text Available An overview of floristic and taxonomic research on vascular plants in Bulgaria during the period of 2005-2016 has been made. The Bulgarian flora currently comprises 4064 species, belonging to 921 genera and 159 families. About 490 published papers were checked, in which 127 species were reported for the first time for the country by Bulgarian or foreign botanists, 11 of these taxa being ones new to science, while 51 are aliens. In the papers checked, 17 subspecies (two of them new to science and 18 hybrids (four of them new to science were also reported for the first time for the country, nine species were confirmed, and another 78 were unconfirmed, synonymised, or erroneously reported. In numerous papers, new localities for various species in different floristic regions in Bulgaria were reported. The books Flora of the Republic of Bulgaria Vol. 11, Red Data Book of the Republic of Bulgaria Vol. 1. Plants and Fungi, Atlas of Endemic Plants in Bulgaria, Invasive Alien Species of Vascular Plants in Bulgaria, Proceedings of Balkan Botanical Congress IV, etc., were published during the given period.

  17. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    Energy Technology Data Exchange (ETDEWEB)

    Dees, C.; Ringleberg, D.; Scott, T.C. [Oak Ridge National Lab., TN (United States); Phelps, T. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  18. The epidermis in Passerina/ (Thymelaeaceae: structure, function and taxonomic significance

    Directory of Open Access Journals (Sweden)

    C. L. Bredenkamp

    2000-02-01

    Full Text Available Epidermal features were studied in all 17 species of Passerina, a genus endemic to southern Africa. Leaves in Passerina are inversely ericoid, the adaxial surface concave and the abaxial surface convex. Leaves are inversely dorsiventral and epistomatic. The adaxial epidermis is villous, with unicellular, uniseriate trichomes and relatively small thin-walled cells, promoting flexibility of leaf margins owing to turgor changes. In common with many other Thymelaeaceae, abaxial epidermal cells are large and tanniniferous with mucilaginous cell walls. The cuticle is adaxially thin, but abaxially well devel­oped, probably enabling the leaf to restrict water loss and to tolerate high light intensity and UV-B radiation. Epicuticular waxes, present in all species, comprise both soft and plate waxes. Epidermal structure proves to be taxonomically impor­tant at family, genus and species levels. Interspecific differences include arrangement of stomata and presence or absence of abaxial epidermal hair. Other diagnostic characters of the abaxial epidermal cells are arrangement,size and shape, cutic- ular ornamentation and presence or absence of wax platelets. Two groups of species on the basis of abaxial epidermal cell orientation are recognised. Many leaf epidermal features in Passerina are interpreted as structural adaptations to the Mediterranean climate of the Cape.

  19. Epidermal characters of Tamarix L. (Tamaricaceae from Northwest China and their taxonomic and palaeogeographic implications

    Directory of Open Access Journals (Sweden)

    Jian-Wei Zhang

    2018-04-01

    Full Text Available The taxonomical position of species of the genus Tamarix (Tamaricaceae has been criticized because of their gross morphological similarities (such as slender, smooth and reddish–brown branches, grey–green foliage and scale leaves, and their systematic relationships remain unclear. In this paper, the leaf epidermal features of 17 species from China are studied based on the micro-morphological characters of the epidermal cells, stomata, salt glands, papillae and epidermal hairs. According to the studies, the leaf epidermal features, together with the character of the flower, are taxonomically clearly distinct. The establishment of Tamarix albiflonum is consolidated. Tamarix korolkowi and Tamarix ramosissima have minimal differences in epidermal characters, and the former is suggested to be a junior synonym. Tamarix ramosissima, Tamarix tarimensis, Tamarix arceuthoides and Tamarix hohenackeri are most similar with respect to their leaf epidermis; considering the common morphological features, habit, distribution and especially the hybridization, it is suggested that these four species are closely genetically related and that the variations among them are probably intraspecific. The new taxonomical evidence indicates the occurrence of 13 species and four variants in China. Presently, Tamarix is a typical plant of arid and semi-arid regions, but its Eocene ancestors lived in warm and humid climates in the coastal areas of the ancient Mediterranean Sea. Thus, the papillae or epidermal hairs, which are outgrowths of the outer epidermal cells facilitating the leaf to respond to water stress and commonly seen in the plants growing in arid or semi-arid areas rather than the plants in warm and humid climates, are of relatively recent origin in Tamarix. The primitive species lack papillae or epidermal hairs, while in evolved species these structures are abundant. Based on the ecological adaptations of the epidermal features, the palaeogeographic

  20. Host and habitat filtering in seedling root-associated fungal communities: taxonomic and functional diversity are altered in 'novel' soils.

    Science.gov (United States)

    Pickles, Brian J; Gorzelak, Monika A; Green, D Scott; Egger, Keith N; Massicotte, Hugues B

    2015-10-01

    Climatic and land use changes have significant consequences for the distribution of tree species, both through natural dispersal processes and following management prescriptions. Responses to these changes will be expressed most strongly in seedlings near current species range boundaries. In northern temperate forest ecosystems, where changes are already being observed, ectomycorrhizal fungi contribute significantly to successful tree establishment. We hypothesised that communities of fungal symbionts might therefore play a role in facilitating, or limiting, host seedling range expansion. To test this hypothesis, ectomycorrhizal communities of interior Douglas-fir and interior lodgepole pine seedlings were analysed in a common greenhouse environment following growth in five soils collected along an ecosystem gradient. Currently, Douglas-fir's natural distribution encompasses three of the five soils, whereas lodgepole pine's extends much further north. Host filtering was evident amongst the 29 fungal species encountered: 7 were shared, 9 exclusive to Douglas-fir and 13 exclusive to lodgepole pine. Seedlings of both host species formed symbioses with each soil fungal community, thus Douglas-fir did so even where those soils came from outside its current distribution. However, these latter communities displayed significant taxonomic and functional differences to those found within the host distribution, indicative of habitat filtering. In contrast, lodgepole pine fungal communities displayed high functional similarity across the soil gradient. Taxonomic and/or functional shifts in Douglas-fir fungal communities may prove ecologically significant during the predicted northward migration of this species; especially in combination with changes in climate and management operations, such as seed transfer across geographical regions for forestry purposes.

  1. CONSTAX: a tool for improved taxonomic resolution of environmental fungal ITS sequences.

    Science.gov (United States)

    Gdanetz, Kristi; Benucci, Gian Maria Niccolò; Vande Pol, Natalie; Bonito, Gregory

    2017-12-06

    One of the most crucial steps in high-throughput sequence-based microbiome studies is the taxonomic assignment of sequences belonging to operational taxonomic units (OTUs). Without taxonomic classification, functional and biological information of microbial communities cannot be inferred or interpreted. The internal transcribed spacer (ITS) region of the ribosomal DNA is the conventional marker region for fungal community studies. While bioinformatics pipelines that cluster reads into OTUs have received much attention in the literature, less attention has been given to the taxonomic classification of these sequences, upon which biological inference is dependent. Here we compare how three common fungal OTU taxonomic assignment tools (RDP Classifier, UTAX, and SINTAX) handle ITS fungal sequence data. The classification power, defined as the proportion of assigned OTUs at a given taxonomic rank, varied among the classifiers. Classifiers were generally consistent (assignment of the same taxonomy to a given OTU) across datasets and ranks; a small number of OTUs were assigned unique classifications across programs. We developed CONSTAX (CONSensus TAXonomy), a Python tool that compares taxonomic classifications of the three programs and merges them into an improved consensus taxonomy. This tool also produces summary classification outputs that are useful for downstream analyses. Our results demonstrate that independent taxonomy assignment tools classify unique members of the fungal community, and greater classification power is realized by generating consensus taxonomy of available classifiers with CONSTAX.

  2. Molecular recircumscription of Broussonetia (Moraceae) and the identity and taxonomic status of B. kaempferi var. australis.

    Science.gov (United States)

    Chung, Kuo-Fang; Kuo, Wen-Hsi; Hsu, Yi-Hsuan; Li, Yi-Hsuan; Rubite, Rosario Rivera; Xu, Wei-Bin

    2017-12-01

    Despite being a relatively small genus, the taxonomy of the paper mulberry genus Broussonetia remains problematic. Much of the controversy is related to the identity and taxonomic status of Broussonetia kaempferi var. australis, a name treated as a synonym in the floras of Taiwan and yet accepted in the floras of China. At the generic level, the monophyly of Corner (Gard Bull Singap 19:187-252, 1962)'s concept of Broussonetia has not been tested. In recent studies of Broussonetia of Japan, lectotypes of the genus were designated and three species (B. kaempferi, Broussonetia monoica, and Broussonetia papyrifera) and a hybrid (B. ×kazinoki) were recognized. Based on the revision and molecular phylogenetic analyses, this article aims to clarify these issues. Herbarium studies, field work, and molecular phylogenetic analyses indicate that all Taiwanese materials identifiable to B. kaempferi var. australis are conspecific with B. monoica of Japan and China. Molecular phylogenetic analyses showed that Broussonetia sensu Corner (Gard Bull Singap 19:187-252, 1962) contains two clades corresponding to sect. Broussonetia and sect. Allaeanthus, with Malaisia scandens sister to sect. Broussonetia. Based on our analyses, B. kaempferi var. australis is treated as a synonym of B. monoica and that B. kaempferi is not distributed in Taiwan. To correct the non-monophyly of Broussonetia sensu Corner (Gard Bull Singap 19:187-252, 1962), Broussonetia is recircumscribed to contain only sect. Broussonetia and the generic status of Allaeanthus is reinstated.

  3. Unbalanced Bilinguals’ Asymmetric Associations Between L2 Words for Taxonomic Categories of Basic and Superordinate Levels

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    Bohua Chen

    2016-03-01

    Full Text Available The revised hierarchical model seems different from the distributed conceptual feature model in predicting how unbalanced bilinguals would be aware of semantic relations between words for taxonomic categories of basic level (exemplar words and words for those of superordinate level (category names in L2. We did a series of four experiments to compare unbalanced bilinguals’ awareness of conceptual relations between exemplar words and between exemplar words and category names in their first (L1 and second language (L2. A priming task of semantic categorization was adopted, and the participants were 72 college students, who began to learn L2 in classroom settings at a late age and achieved an L2 proficiency between intermediate and advanced levels. The reaction times indicated that the participants could automatically process not only the exemplar-word but also the category-name primes in L2. Activations of semantic representations for the category names in L2 seemed to spread to those for the exemplar words in L1 and L2, but activations of semantic presentations for the exemplar words in L2 spread only to those for the example words in L1 for the participants. It was concluded that unbalanced bilinguals appear to have developed asymmetric associations between category names and exemplar words in L2. The implication is that L2 learners should learn L2 words mainly by means of using the language and not taking rote memory of isolated words.

  4. A taxonomic review of the Neoserica (sensu lato) abnormis group (Coleoptera, Scarabaeidae, Sericini)

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    Ahrens, Dirk; Liu, Wan-Gang; Fabrizi, Silvia; Bai, Ming; Yang, Xing-Ke

    2014-01-01

    Abstract The present paper revises the species belonging to the Neoserica (sensu lato) abnormis group, so far known only with two nominal species. Twenty new species are herein described from Indochina and southern China: N. abnormoides sp. n. (Vietnam, China), N. allolaotica sp. n., N. namthaensis sp. n., N. simplicissima sp. n. (Laos), N. thailandensis sp. n. (Thailand), N. alloputaoana sp. n., N. kanphantensis sp. n., N. natmatoungensis sp. n., N. putaoana sp. n., N. taunggyiana sp. n. (Myanmar), N. lamellosa sp. n., N. tonkinea sp. n. (Vietnam), N. bairailingshanica sp. n., N. euyunnanica sp. n., N. huangi sp. n., N. jiangxiensis sp. n., N. trifida sp. n., N. yaoi sp. n., N. yingjiangensis sp. n. (China), N. cardamomensis sp. n. (Indochina and southern China). One new combination is established: Neoserica ponderosa Arrow, 1946, comb. n. The lectotypes of Neoserica abnormis Moser, 1908 and the taxonomically uncertain N. inclinata Brenske, 1898, which very likely also belongs to this species group, are designated herein. A key to the species and to species groups is given, the genitalia of all species including their habitus are illustrated. Maps of species distribution are included. PMID:25317056

  5. A taxonomic review of the Neoserica (sensu lato abnormis group (Coleoptera, Scarabaeidae, Sericini

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    Dirk Ahrens

    2014-09-01

    Full Text Available The present paper revises the species belonging to the Neoserica (sensu lato abnormis group, so far known only with two nominal species. Twenty new species are herein described from Indochina and southern China: N. abnormoides sp. n. (Vietnam, China, N. allolaotica sp. n., N. namthaensis sp. n., N. simplicissima sp. n. (Laos, N. thailandensis sp. n. (Thailand, N. alloputaoana sp. n., N. kanphantensis sp. n., N. natmatoungensis sp. n., N. putaoana sp. n., N. taunggyiana sp. n. (Myanmar, N. lamellosa sp. n., N. tonkinea sp. n. (Vietnam, N. bairailingshanica sp. n., N. euyunnanica sp. n., N. huangi sp. n., N. jiangxiensis sp. n., N. trifida sp. n., N. yaoi sp. n., N. yingjiangensis sp. n. (China, N. cardamomensis sp. n. (Indochina and southern China. One new combination is established: Neoserica ponderosa Arrow, 1946, comb. n. The lectotypes of Neoserica abnormis Moser, 1908 and the taxonomically uncertain N. inclinata Brenske, 1898, which very likely also belongs to this species group, are designated herein. A key to the species and to species groups is given, the genitalia of all species including their habitus are illustrated. Maps of species distribution are included.

  6. Taxonomic and Functional Diversity of a Quercus pyrenaica Willd. Rhizospheric Microbiome in the Mediterranean Mountains

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    José F. Cobo-Díaz

    2017-10-01

    Full Text Available Altitude significantly affects vegetation growth and distribution, including the developmental stages of a forest. We used shotgun Illumina sequencing to analyze microbial community composition and functional potential in melojo-oak (Quercus pyrenaica Willd. rhizospheric soil for three different development stages along an altitudinal gradient: (a a low altitude, non-optimal site for forest maintenance; (b an intermediate altitude, optimal site for a forest; and (c a high altitude, expansion site with isolated trees but without a real forest canopy. We observed that, at each altitude, the same microbial taxa appear both in the taxonomic analysis of the whole metagenome and in the functional analysis of the methane, sulfur and nitrogen metabolisms. Although there were no major differences at the functional level, there were significant differences in the abundance of each taxon at the phylogenetic level between the rhizospheres of the forest (low and intermediate altitudes and the expansion site. Proteobacteria and Actinobacteria were the most differentially abundant phyla in forest soils compared to the expansion site rhizosphere. Moreover, Verrucomicrobia, Bacteroidetes and Nitrospirae phyla were more highly represented in the non-forest rhizosphere. Our study suggests that rhizospheric microbial communities of the same tree species may be affected by development stage and forest canopy cover via changes in soil pH and the C/N ratio.

  7. Taxonomic revision and phylogenetic position of Osteocephalus festae (Anura, Hylidae) with description of its larva

    Science.gov (United States)

    Ron, Santiago R.; Toral, Eduardo; Venegas, Pablo J.; Barnes, Charles W.

    2010-01-01

    Abstract Osteocephalus festae is an Amazonian species recently resurrected from a synonymy with Osteocephalus buckleyi. Because few specimens are known, its morphological variation, diagnostic characters, and distribution are poorly understood. Herein we determine its phylogenetic relationships and provide a complete taxonomic account based on recently collected specimens (adults and larvae) from nine localities in Ecuador and Peru. Osteocephalus festae is most similar to Osteocephalus verruciger from which it differs in having less tuberculate dorsal skin on males, smaller tympanum, and more tooth rows in the oral disk of larvae. A phylogeny based on mitochondrial DNA sequences, genes 12S and ND1, shows that Osteocephalus festae is closely related to Osteocephalus buckleyi, Osteocephalus mutabor and Osteocephalus verruciger. A clade consisting of Osteocephalus festae, Osteocephalus verruciger, and Osteocephalus buckleyi is characterized by stream dwelling tadpoles. Surprisingly, we found paraphyly among Ecuadorian populations of Osteocephalus buckleyi and Osteocephalus verruciger. The causes for paraphyly are unknown but in Osteocephalus buckleyi may result from the existence of cryptic species. PMID:21594044

  8. Taxonomic revision of Stigmatomma Roger (Hymenoptera: Formicidae) in the Malagasy region

    Science.gov (United States)

    Fisher, Brian L.

    2016-01-01

    Abstract In this study we present the first taxonomic revision of the ant genus Stigmatomma in the Malagasy biogeographic region, re­describe the previously known S. besucheti Baroni-Urbani, and describe seven new species to science (S. bolabola sp. n., S. irayhady sp. n., S. janovitsika sp. n., S. liebe sp. n., S. roahady sp. n., S. sakalava sp. n., and S. tsyhady sp. n.). The revision is based on the worker caste, but we provide brief descriptions of gynes and males for some species. Species descriptions, diagnosis, character discussion, identification key, and glossary are illustrated with 360 high-quality montage and SEM images. The distribution of Stigmatomma species in Madagascar are mapped and discussed within the context of the island’s biomes and ecoregions. We also discuss how some morphometric variables describe the differences among the species in the bioregion. Open science is supported by providing access to R scripts, raw measurement data, and all specimen data used. All specimens used in this study were given unique identifies, and holotypes were imaged. Specimens and images are made accessible on AntWeb.org. PMID:27433124

  9. Taxonomic notes on the afrotropical genera Hapalogenius Hagedorn, Hylesinopsis Eggers, and Rhopalopselion Hagedorn (Coleoptera, Curculionidae, Scolytinae

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    Roger Beaver

    2010-09-01

    Full Text Available Taxonomic confusion among the afrotropical scolytine genera Hapalogenius Hagedorn, Hylesinopsis Eggers and Rhopalopselion Hagedorn, and their synonyms is discussed with especial reference to the catalogues of Wood and Bright (1992, and Alonso-Zarazaga and Lyal (2009. A key is given to separate the three genera recognised, and the species considered to be included in each genus are listed. Hylesinopsis is resurrected from synonymy with Hapalogenius, and shown not to be closely related to it. Chilodendron Schedl is considered to be a synonym of Hylesinopsis and not of Xylechinus Chapuis. The following new synonymy is proposed at specific level: Hapalogenius africanus (Eggers (= Hapalogenius lesnei Eggers, = Metahylesinus brincki Schedl; Hapalogenius fuscipennis (Chapuis (= Hapalogenius bimaculatus Eggers; Hapalogenius oblongus (Eggers (= Metahylesinus striatus Schedl; Hylesinopsis fasciata (Hagedorn (= Kissophagus punctatus Eggers; Phrixosoma niger Eggers (= Hapalogenius niger Schedl. The following species are returned to Hylesinopsis from Hapalogenius to which they were transferred by Alonso-Zarazaga and Lyal (2009: Hylesinopsis alluaudi (Lepesme, H. angolensis (Schedl, H. arabiae (Schedl, H. atra (Nunberg, H. confusa (Eggers, H. decellei (Nunberg, H. dubia Eggers, H. emarginata (Nunberg, H. fasciata (Hagedorn, H. ficus (Schedl, H. granulata (Lepesme, H. hirsuta (Schedl, H. joveri (Schedl, H. pauliani (Lepesme, H. punctata (Eggers, H. saudiarabiae (Schedl. The following new combination is given: Hylesinopsis leprosula (Browne from Cryphalus Erichson. New distributional records are given for some species.

  10. Taxonomic hypotheses regarding the genus Gerbillus (Rodentia, Muridae, Gerbillinae) based on molecular analyses of museum specimens

    Science.gov (United States)

    Ndiaye, Arame; Tatard, Caroline; Stanley, William; Granjon, Laurent

    2016-01-01

    Abstract Methodological improvements now allow routine analyses of highly degraded DNA samples as found in museum specimens. Using these methods could be useful in studying such groups as rodents of the genus Gerbillus for which i) the taxonomy is still highly debated, ii) collection of fresh specimens may prove difficult. Here we address precise taxonomic questions using a small portion of the cytochrome b gene obtained from 45 dry skin/skull museum samples (from 1913 to 1974) originating from two African and three Asian countries. The specimens were labelled Gerbillus gerbillus, Gerbillus andersoni, Gerbillus nanus, Gerbillus amoenus, Gerbillus perpallidus and Gerbillus pyramidum, and molecular results mostly confirmed these assignations. The close relationship between Gerbillus nanus (Asian origin) and Gerbillus amoenus (African origin) confirmed that they represent vicariant sibling species which differentiated in allopatry on either side of the Red Sea. In the closely related Gerbillus perpallidus and Gerbillus pyramidum, specimens considered as belonging to one Gerbillus pyramidum subspecies (Gerbillus pyramidum floweri) appeared closer to Gerbillus perpallidus suggesting that they (Gerbillus pyramidum floweri and Gerbillus perpallidus) may represent a unique species, distributed on both sides of the Nile River, for which the correct name should be Gerbillus floweri. Furthermore, the three other Gerbillus pyramidum subspecies grouped together with no apparent genetic structure suggesting that they may not yet represent genetically differentiated lineages. This study confirms the importance of using these methods on museum samples, which can open new perspectives in this particular group as well as in other groups of interest. PMID:27047247

  11. Taxonomic revision of the fossil pulmonate mollusks of Itaboraí Basin (Paleocene, Brazil

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    Rodrigo Brincalepe Salvador

    2013-01-01

    Full Text Available The limestones of Itaboraí Basin (Middle Paleocene, Rio de Janeiro, Brazil, harbor a rich fossil molluscan fauna consisting exclusively of pulmonate snails, both terrestrial and freshwater. An extensive taxonomic revision of this paleofauna is conducted here. A new genus, Cortana, is described as well as two new species, Eoborus fusiforme and Gastrocopta itaboraiensis. The revised classification is as follows: Austrodiscus lopesi (Charopidae; Biomphalaria itaboraiensis (Planorbidae; "Brachypodella" britoi (Urocoptidae; Brasilennea arethusae, Brasilennea guttula, Brasilennea minor (Cerionidae; Bulimulus fazendicus, Bulimulus trindadeae, Cortana carvalhoi, Cyclodontina coelhoi, Itaborahia lamegoi, Leiostracus ferreirai, Plagiodontes aff. dentatus (Orthalicidae; Cecilioides sommeri (Ferussaciidae; Eoborus rotundus, Eoborus sanctijosephi, Eoborus fusiforme (Strophocheilidae; Gastrocopta mezzalirai, Gastrocopta itaboraiensis (Gastrocoptidae; Temesa magalhaesi (Clausiliidae. The species Strobilopsis mauryae was considered a synonym of Brasilennea arethusae; Bulimulus sommeri a synonym of Itaborahia lamegoi; and Vorticifex fluminensis a synonym of Eoborus sanctijosephi. Itaboraí Basin has the most ancient records of the families Orthalicidae, Gastrocoptidae, Ferussaciidae and Strophocheilidae. Moreover, the basin's records of Charopidae, Clausiliidae, Cerionidae, and Urocoptidae are among the most ancient in the world and, among these, those of Cerionidae, Clausiliidae and Urocoptidae deserve special attention since they are greatly removed from these families' current distribution. Additionally, Itaboraí has the most ancient records for the genera Austrodiscus, Brachypodella, Bulimulus, Cecilioides, Cyclodontina, Eoborus, Gastrocopta, Leiostracus, Plagiodontes and Temesa. There are three endemic genera in the basin: Brasilennea, Cortana and Itaborahia. Further discussion on paleobiogeography and evolution of this paleofauna is also provided.

  12. Taxonomic revision of the species of Colletes Latreille, 1802 (Hymenoptera: Colletidae: Colletinae) found in Chile.

    Science.gov (United States)

    Ferrari, Rafael R

    2017-12-13

    A taxonomic revision of Colletes Latreille species with known geographic distribution in Chile is presented. In addition to the traditional morphological approach to taxonomy, DNA barcoding was employed to facilitate sexual association and cryptic species recognition. I provide diagnoses, synonymies, geographic and floral records, and a fully-illustrated key for 31 recognized species, 23 of them previously described: C. alocochila Moure, C. atacamensis Janvier, C. atripes Smith, C. bicolor Smith, C. chusmiza Rojas & Toro, C. cognatus Spinola, C. cyanescens (Haliday), C. cyaniventris Spinola n. stat., C. flaminii Moure, C. fulvipes Spinola, C. gilvus Vachal, C. guanta Rojas & Toro, C. longiceps Friese, C. lucens Vachal, C. mastochila Moure, C. murinus Friese, C. musculus Friese, C. nigritulus Friese, C. patagonicus Schrottky, C. quelu Rojas & Toro, C. rutilans Vachal, C. sulcatus Vachal, and C. vicugnensis Rojas & Toro. In addition, eight new species are described: C. arthuri n. sp., C. coquimbensis n. sp., C. flavipilosus n. sp., C. kuhlmanni n. sp., C. nigropilosus n. sp., C. simulatus n. sp., C. toroi n. sp., and C. ventricarinatus n. sp. Lectotypes for the following species are designated: Andrena cyanescens, Colletes bicolor, C. campoi Herbst, C. chubutensis Cockerell, C. gilvus, C. lucens, C. patagonicus, C. rufosignatus Cockerell, and C. viridans Vachal. Colletes seminitidus Spinola and C. viridans are both proposed as junior synonyms of C. cyanescens, and C. araucariae Friese is considered a junior synonym of C. sulcatus. Colletes cyaniventris n. stat. is resurrected from synonymy.

  13. TAXONOMIC REVISION OF THE TIGRINA LEOPARDUS TIGRINUS (SCHREBER, 1775 SPECIES GROUP (CARNIVORA, FELIDAE

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    FABIO OLIVEIRA DO NASCIMENTO

    Full Text Available ABSTRACT The tigrina Leopardus tigrinus (Schreber, 1775 is a small-sized Neotropical spotted cat found from northern Argentina and southern Brazil to Costa Rica. Four subspecies are traditionally recognized: L. t. tigrinus (Schreber, 1775 from northern Brazil, the Guianas and eastern Venezuela; L. t. pardinoides (Gray, 1867 from western Venezuela, Colombia, Ecuador and Peru; L. t. guttulus (Hensel, 1872 from southern Brazil, Paraguay and northern Argentina; and L. t. oncillus (Thomas, 1903 from Costa Rica. We studied external and craniodental morphology in quantitative and qualitative terms from 250 specimens in order to clarify the taxonomic status of tigrina. Based on the characters analyzed in this study, we recognize three diagnosable morphogroups, each with a distinct geographic distribution: northern/northwestern/west (samples from northern Brazil, the Guianas, Venezuela, Colombia, Ecuador, Peru, northwestern Argentina and Costa Rica, eastern (samples from northeastern and central Brazil, and southern (samples from southern Brazil, Paraguay and northeastern Argentina. Taking into account the morphologic evidence presented here, supported by biogeographic data and molecular studies available, we recognize three full species for tigrinas: L. tigrinus (including the putative subspecies L. t. pardinoides and L. t. oncillus as junior synonyms for northern/northwestern/west group; L. emiliae (Thomas, 1914 for eastern group; and L. guttulus for southern group.

  14. Taxonomic formula of geoecological hazard for the cadastral districts of Moscow city

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    Karfidova E.A.

    2018-01-01

    Full Text Available the article proposes a method for calculating the taxonomic formula for the geoecological hazard of the cadastral district. The engineering-geological zoning map uses for calculating the balance of the territory by the hazard index – the basis of the taxonomic formula. The taxonomic formula as an open data set makes it possible to characterize the geoecological hazards of the territory of a district. The geoenvironmental hazard map of cadastral districts is necessary for regional model of spatial planning at the municipal level.

  15. Testing the taxonomic integrity of Paranthropus boisei sensu stricto.

    Science.gov (United States)

    Silverman, N; Richmond, B; Wood, B

    2001-06-01

    The craniodental hypodigm of Paranthropus boisei sensu stricto is morphologically distinctive, but it has been suggested that the substantial variation in mandibular and dental size in that hypodigm may exceed that which is reasonable to subsume within a single hominin species. In this study, Fligner and Killeen, coefficient of variation (CV)-based and average taxonomic distance (ATD)-based bootstrap tests, were used to compare variation in size and shape of the mandibular corpus remains attributed to P. boisei s.s. with the variation observed in samples of great apes and modern humans. The degree of size variation in the P. boisei s.s. mandibular hypodigm is never observed in human and chimpanzee samples, is rare in gorillas, but is not uncommon in orangutans. However, the shape variation in the fossil group is comparable to the variation in the extant reference groups. Although the size variation in P. boisei s.s. is substantial, it is exaggerated by the effects of taphonomy. The small mandibles are more often abraded, whereas the large mandibles are more likely to have been infiltrated with matrix. On the basis of the results of this investigation of the mandibular corpus, there are no grounds for rejecting the "single-species" hypothesis for P. boisei s.s. When Sokal and Braumann's adjusted CV values were used to predict the index of sexual dimorphism (ISD) for the P. boisei s.s., despite the substantial geological time embraced by the mandibular corpus hypodigm, the predicted value of lnISD, when corrected for taphonomic factors, is comparable to the sexual dimorphism observed within Gorilla. Copyright 2001 Wiley-Liss, Inc.

  16. EAU standardised medical terminology for urologic imaging: a taxonomic approach.

    Science.gov (United States)

    Loch, Tillmann; Carey, Brendan; Walz, Jochen; Fulgham, Pat Fox

    2015-05-01

    The terminology and abbreviations used in urologic imaging have generally been adopted on an ad hoc basis by different speciality groups; however, there is a need for shared nomenclature to facilitate clinical communication and collaborative research. This work reviews the current nomenclature for urologic imaging used in clinical practice and proposes a taxonomy and terminology for urologic imaging studies. A list of terms used in urologic imaging were compiled from guidelines published by the European Association of Urology and the American Urological Association and from the American College of Radiology Appropriateness Criteria. Terms searched were grouped into broad categories based on technology, and imaging terms were further stratified based on the anatomic extent, contrast or phases, technique or modifiers, and combinations or fusions. Terms that had a high degree of utilisation were classified as accepted. We propose a new taxonomy to define a more useful and acceptable nomenclature model acceptable to all health professionals involved in urology. The major advantage of a taxonomic approach to the classification of urologic imaging studies is that it provides a flexible framework for classifying the modifications of current imaging modalities and allows the incorporation of new imaging modalities. The adoption of this hierarchical classification model ranging from the most general to the most detailed descriptions should facilitate hierarchical searches of the medical literature using both general and specific terms. This work is limited in its scope, as it is not currently all-inclusive. This will hopefully be addressed by future modification as others embrace the concept and work towards uniformity in nomenclature. This paper provides a noncomprehensive list of the most widely used terms across different specialties. This list can be used as the basis for further discussion, development, and enhancement. In this paper we describe a classification system

  17. Phanoceroides Hinton, 1939: description of new species, morphology of larvae, and revised taxonomic position of the genus (Coleoptera: Elmidae) based on molecular evidence.

    Science.gov (United States)

    Čiampor, Fedor Jr; Laššová, Kristína; Maier, Crystal A; Čiamporová-Zaťovičová, Zuzana; Kodada, Ján

    2016-05-31

    The monotypic genus Phanoceroides was initially classified within the subfamily Elminae, based solely on the distribution and type of pubescence on the body surface. Although a close relationship with Larainae was suggested (Hinton 1939, Maier 2013), its taxonomic position and phylogeny remained unresolved. Based on newly collected material, we describe here P. fernandesi sp. n. and document morphological characters and differences of adults and larvae of P. aquaticus Hinton, 1939 and P. fernandesi sp. n. To clarify the taxonomic position of Phanoceroides within Elmidae, we used molecular data (cox1 and mtDNA). The results support position of the genus within the subfamily Larainae with Hypsilara Maier & Spangler, 2011 as a close relative.

  18. A taxonomic, functional, and phylogenetic perspective on the community assembly of passerine birds along an elevational gradient in southwest China.

    Science.gov (United States)

    He, Xuelian; Luo, Kang; Brown, Calum; Lin, Luxiang

    2018-03-01

    Integrating multiple facets of biodiversity to describe spatial and temporal distribution patterns is one way of revealing the mechanisms driving community assembly. We assessed the species, functional, and phylogenetic composition and structure of passerine bird communities along an elevational gradient both in wintering and breeding seasons in the Ailao Mountains, southwest China, in order to identify the dominant ecological processes structuring the communities and how these processes change with elevation and season. Our research confirms that the highest taxonomic diversity, and distinct community composition, was found in the moist evergreen broadleaf forest at high elevation in both seasons. Environmental filtering was the dominant force at high elevations with relatively cold and wet climatic conditions, while the observed value of mean pairwise functional and phylogenetic distances of low elevation was constantly higher than expectation in two seasons, suggested interspecific competition could play the key role at low elevations, perhaps because of relative rich resource result from complex vegetation structure and human-induced disturbance. Across all elevations, there was a trend of decreasing intensity of environmental filtering whereas increasing interspecific competition from wintering season to breeding season. This was likely due to the increased resource availability but reproduction-associated competition in the summer months. In general, there is a clear justification for conservation efforts to protect entire elevational gradients in the Ailao Mountains, given the distinct taxonomic, functional, and phylogenetic compositions and also elevational migration pattern in passerine bird communities.

  19. Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

    Science.gov (United States)

    Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

    2015-01-01

    The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation.

  20. Taxonomic and functional patterns of macrobenthic communities on a high-Arctic shelf: A case study from the Laptev Sea

    Science.gov (United States)

    Kokarev, V. N.; Vedenin, A. A.; Basin, A. B.; Azovsky, A. I.

    2017-11-01

    The studies of functional structure of high-Arctic Ecosystems are scarce. We used data on benthic macrofauna from 500-km latitudinal transect in the eastern Laptev Sea, from the Lena delta to the continental shelf break, to describe spatial patterns in species composition, taxonomic and functional structure in relation to environmental factors. Both taxonomy-based approach and Biological Trait analysis yielded similar results and showed general depth-related gradient in benthic diversity and composition. This congruence between taxonomical and functional dimensions of community organization suggests that the same environmental factors (primarily riverine input and regime of sedimentation) have similar effect on both community structure and functioning. BTA also revealed a distinct functional structure of stations situated at the Eastern Lena valley, with dominance of motile, burrowing sub-surface deposit-feeders and absence of sedentary tube-dwelling forms. The overall spatial distribution of benthic assemblages corresponds well to that described there in preceding decades, evidencing the long-term stability of bottom ecosystem. Strong linear relationship between species and traits diversity, however, indicates low functional redundancy, which potentially makes the ecosystem susceptible to a species loss or structural shifts.

  1. Functional diversification within bacterial lineages promotes wide functional overlapping between taxonomic groups in a Mediterranean forest soil.

    Science.gov (United States)

    Curiel Yuste, Jorge; Fernandez-Gonzalez, Antonio José; Fernandez-Lopez, Manuel; Ogaya, Romá; Penuelas, Josep; Lloret, Francisco

    2014-10-01

    We investigated the relationship between taxonomy and functioning of soil bacterial communities in soils from a Mediterranean holm oak forest using a high-throughput DNA pyrosequencing technique. We used nonparametric tests (Mann-Whitney U-test) to evaluate the sensitivity of each single bacterial genus within the community to the fluctuations of plant physiological and environmental abiotic variables, as well as to fluctuations in soil microbial respiration. Within-lineage (phylum/class) functional similarities were evaluated by the distribution of the Mann-Whitney U-test standardized coefficients (z) obtained for all genera within a given lineage. We further defined different ecological niches and within-lineage degree of functional diversification based on multivariate analyses (principal component analyses, PCA). Our results indicate that strong within-lineage functional diversification causes extensive functional overlapping between lineages, which hinders the translation of taxonomic diversity into a meaningful functional classification of bacteria. Our results further suggest a widespread colonization of possible ecological niches as taxonomic diversity increases. While no strong functional differentiation could be drawn from the analyses at the phylum/class level, our results suggest a strong ecological niche differentiation of bacteria based mainly on the distinct response of Gram-positive and Gram-negative bacteria to fluctuations in soil moisture. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  2. Taxonomic study of Hoplias microlepis (Günther, 1864, a trans-Andean species of trahiras (Ostariophysi: Characiformes: Erythrinidae

    Directory of Open Access Journals (Sweden)

    George M. T. Mattox

    Full Text Available The Hoplias malabaricus species group represents one of the most complexes taxonomical problems in the systematics of Neotropical fishes, including specimens widely distributed in most drainages of South America and part of Central America with great variation or overlap of putative diagnostic characters. The large number of nominal species, many of which without known type material, renders the problem more complicated. Currently, at least three nominal species can be included in the Hopliasmalabaricusspecies group based on the form of the medial margins of dentaries and presence of tooth plates on the tongue: Hoplias malabaricus, H. teres, and H. microlepis, the latter representing the only exclusively trans-Andean known species of the genus. We present herein a taxonomic study of Hoplias microlepis based on examination of syntypes and recently collected specimens, including a redescription of the species. Hoplias microlepisoccurs in the Pacific drainages of Panama and Southwestern Costa Rica, in addition to the río Guayas basin in Ecuador and the region near its mouth (río Tumbes, Northwestern Peru. Records of the species on the Atlantic coast of Panama are restricted to the Canal Zone, suggesting dispersal through the Panama Canal. We also designate lectotype and paralectotypes.

  3. Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa

    Science.gov (United States)

    Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

    2015-01-01

    The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation. PMID:25978319

  4. Palyno-morphological characteristics of gymnosperm flora of pakistan and its taxonomic implications with LM and SEM methods.

    Science.gov (United States)

    Khan, Raees; Ul Abidin, Sheikh Zain; Ahmad, Mushtaq; Zafar, Muhammad; Liu, Jie; Amina, Hafiza

    2018-01-01

    The present study is intended to assess gymnosperms pollen flora of Pakistan using Light Microscope (LM) and Scanning Electron Microscopy (SEM) for its taxonomic significance in identification of gymnosperms. Pollens of 35 gymnosperm species (12 genera and five families) were collected from its various distributional sites of gymnosperms in Pakistan. LM and SEM were used to investigate different palyno-morphological characteristics. Five pollen types (i.e., Inaperturate, Monolete, Monoporate, Vesiculate-bisaccate and Polyplicate) were observed. Six In equatorial view seven types of pollens were observed, in which ten species were sub-angular, nine species were Traingular, six species were Perprolate, three species were Rhomboidal, three species were semi-angular, two species were rectangular and two species were prolate. While five types of pollen were observed in polar view, in which ten species were Spheroidal, nine species were Angular, eight were Interlobate, six species were Circular, two species were Elliptic. Eighteen species has rugulate and 17 species has faveolate ornamentation. Eighteen species has verrucate and 17 have gemmate type sculpturing. The data was analysed through cluster analysis. The study showed that these palyno-morphological features have significance value in classification and identification of gymnosperms. Based on these different palyno-morphological features, a taxonomic key was proposed for the accurate and fast identifications of gymnosperms from Pakistan. © 2017 Wiley Periodicals, Inc.

  5. Taxonomic revision of Eoalligator (Crocodylia, Brevirostres and the paleogeographic origins of the Chinese alligatoroids

    Directory of Open Access Journals (Sweden)

    Yan-yin Wang

    2016-08-01

    Full Text Available Background. The primarily Neotropical distribution of living alligatoroids raises questions as to when and how the ancestors of Alligator sinensis migrated to China. As phylogeny provides a necessary framework for historical biogeographic issues, determining the phylogenetic positions of the Chinese alligatoroids is a crucial step towards understanding global alligatoroid paleobiogeography. Besides the unnamed alligatoroids from the Eocene of Guangdong Province, three Chinese fossil taxa have been referred to Alligatoroidea: Alligator luicus, Eoalligator chunyii and Eoalligator huiningensis. However, none of these fossil taxa has been included in a phylogenetic analysis. The genus Eoalligator was established to accommodate E. chunyii from Guangdong Province. E. huiningensis from Anhui Province was later erected as a second species, despite no distinctive similarities with E. chunyii. By contrast, the putative crocodyline Asiatosuchus nanlingensis was established based on material from Guangdong Province, close to the E. chunyii specimens geographically and stratigraphically. Furthermore, specimens of A. nanlingensis and E. chunyii share four distinctive characters, but display no evident differences. As a result, the taxonomic relationships of these three species require restudy. Methods. In this paper, all specimens of E. chunyii and E. huiningensis are reassessed in detail, and compared to specimens of A. nanlingensis. Detailed re-descriptions and revised diagnoses are provided, and a cladistic analysis is carried out to assess the phylogenetic positions of E. chunyii, E. huiningensis and A. nanlingensis. Results. The analysis recovers E. chunyii and A. nanlingensis as sister taxa among basal Crocodylidae, while P. huiningensis is posited as an alligatoroid. Two key characters support the monophyly E. chunyii + A. nanlingensis: sulcus within surangular, and anteroposteriorly oriented surangular-articular suture. The former character is unique

  6. Chaetopteryx bucari sp. n., a new species from the Chaetopteryx rugulosa group from Croatia (Insecta, Trichoptera, Limnephilidae) with molecular, taxonomic and ecological notes on the group.

    Science.gov (United States)

    Kučinić, Mladen; Szivák, Ildikó; Pauls, Steffen U; Bálint, Miklós; Delić, Antun; Vučković, Ivan

    2013-01-01

    We describe a new autumnal caddisfly species Chaetopteryx bucari sp. n. from 8 localities in the Banovina region of Croatia. We also present molecular, taxonomic and ecological notes (emergence, sex ratio and seasonal dynamics) on the new species and discuss the distribution of Chaetopteryx species in general and the Chaetopteryx rugulosa group in particular. Based on Bayesian phylogenetic analysis Chaetopteryx rugulosa schmidi was separated from the clade containing the other subspecies of Chaetopteryx rugulosa. Thus the subspecies Chaetopteryx rugulosa schmidi is here raised to species level, Chaetopteryx schmidi, as it was described originally. We further present distribution data on rare species in the genus Chaetopteryx in Croatia.

  7. Chaetopteryx bucari sp. n., a new species from the Chaetopteryx rugulosa group from Croatia (Insecta, Trichoptera, Limnephilidae with molecular, taxonomic and ecological notes on the group

    Directory of Open Access Journals (Sweden)

    Mladen Kučinić

    2013-07-01

    Full Text Available We describe a new autumnal caddisfly species Chaetopteryx bucari sp. n. from 8 localities in the Banovina region of Croatia. We also present molecular, taxonomic and ecological notes (emergence, sex ratio and seasonal dynamics on the new species and discuss the distribution of Chaetopteryx species in general and the C. rugulosa group in particular. Based on Bayesian phylogenetic analysis C. rugulosa schmidi was separated from the clade containing the other subspecies of C. rugulosa. Thus the subspecies C. r. schmidi is here raised to species level, C. schmidi, as it was described originally. We further present distribution data on rare species in the genus Chaetopteryx in Croatia.

  8. Asian longhorned beetle complicates the relationship between taxonomic diversity and pest vulnerability in street tree assemblages

    Data.gov (United States)

    U.S. Environmental Protection Agency — Urban foresters routinely emphasise the importance of taxonomic diversity to reduce the vulnerability of tree assemblages to invasive pests, but it is unclear to...

  9. Taxonomic utility of female copulation organs in Sericini chafers (Coleoptera, Scarabaeidae), with special reference to asymmetry

    NARCIS (Netherlands)

    Özgül-Siemund, A.; Ahrens, D.

    2015-01-01

    Female genitalia are widely underrepresented in taxonomic studies. Here we investigate the morphological variation among female copulation organs for a group of scarab beetles (Sericini) with similar ecology, external morphology and copulation mechanics. We examined traits qualitatively and

  10. Partitioning taxonomic diversity of aquatic insect assemblages and functional feeding groups in Neotropical Savanna headwater streams

    Science.gov (United States)

    Biological diversity can be divided into: alpha (α, local), beta (β, difference in assemblage composition among locals), and gamma (γ, total diversity). We assessed the partitioning of taxonomic diversity of Ephemeroptera, Plecoptera and Trichoptera (EPT) and of functional feedin...

  11. Partitioning taxonomic diversity of aquatic insect assemblages and functional feeding groups in Neotropical Savanna headwater streams

    Science.gov (United States)

    Biological diversity can be divided into: alpha (α, local), beta (β, difference in assemblage composition among locals), and gamma (γ, total diversity). We assessed the partitioning of taxonomic diversity of Ephemeroptera, Plecoptera and Trichoptera (EPT) and of ...

  12. Analysing taxonomic structures and local ecological processes in temperate forests in North Eastern China.

    Science.gov (United States)

    Fan, Chunyu; Tan, Lingzhao; Zhang, Chunyu; Zhao, Xiuhai; von Gadow, Klaus

    2017-10-30

    One of the core issues of forest community ecology is the exploration of how ecological processes affect community structure. The relative importance of different processes is still under debate. This study addresses four questions: (1) how is the taxonomic structure of a forest community affected by spatial scale? (2) does the taxonomic structure reveal effects of local processes such as environmental filtering, dispersal limitation or interspecific competition at a local scale? (3) does the effect of local processes on the taxonomic structure vary with the spatial scale? (4) does the analysis based on taxonomic structures provide similar insights when compared with the use of phylogenetic information? Based on the data collected in two large forest observational field studies, the taxonomic structures of the plant communities were analyzed at different sampling scales using taxonomic ratios (number of genera/number of species, number of families/number of species), and the relationship between the number of higher taxa and the number of species. Two random null models were used and the "standardized effect size" (SES) of taxonomic ratios was calculated, to assess possible differences between the observed and simulated taxonomic structures, which may be caused by specific ecological processes. We further applied a phylogeny-based method to compare results with those of the taxonomic approach. As expected, the taxonomic ratios decline with increasing grain size. The quantitative relationship between genera/families and species, described by a linearized power function, showed a good fit. With the exception of the family-species relationship in the Jiaohe study area, the exponents of the genus/family-species relationships did not show any scale dependent effects. The taxonomic ratios of the observed communities had significantly lower values than those of the simulated random community under the test of two null models at almost all scales. Null Model 2 which

  13. A review of the taxonomic status and biology of the Cape Parrot ...

    African Journals Online (AJOL)

    A review of the taxonomic status and biology of the Cape Parrot Poicephalus robustus , with reference to the Brown-necked Parrot P. fuscicollis fuscicollis and the Grey-headed Parrot P. f. suahelicus.

  14. Taxonomic and ecological studies of actinomycetes from Vietnam: isolation and genus-level diversity.

    Science.gov (United States)

    Hop, Duong Van; Sakiyama, Yayoi; Binh, Chu Thi Thanh; Otoguro, Misa; Hang, Dinh Thuy; Miyadoh, Shinji; Luong, Dao Thi; Ando, Katsuhiko

    2011-09-01

    Actinomycetes were isolated from 109 soil and 93 leaf-litter samples collected at five sites in Vietnam between 2005 and 2008 using the rehydration-centrifugation (RC) method, sodium dodecyl sulfate-yeast extract dilution method, dry-heating method and oil-separation method in conjunction with humic acid-vitamin agar as an isolation medium. A total of 1882 strains were identified as Vietnamese (VN)-actinomycetes including 1080 (57%) streptomycetes (the genus Streptomyces isolates) and 802 (43%) non-streptomycetes. The 16S ribosomal RNA gene sequences of the VN-actinomycetes were analyzed using BLAST searches. The results showed that these isolates belonged to 53 genera distributed among 21 families. Approximately 90% of these strains were members of three families: Streptomycetaceae (1087 strains, 58%); Micromonosporaceae (516 strains, 27%); and Streptosporangiaceae (89 strains, 5%). Motile actinomycetes of the genera Actinoplanes, Kineosporia and Cryptosporangium, which have quite common morphological characteristics, were frequently isolated from leaf-litter samples using the RC method. It is possible that these three genera acquired common properties during a process of convergent evolution. By contrast, strains belonging to the suborder Streptosporangineae were exclusively isolated from soils. A comparison of the sampling sites revealed no significant difference in taxonomic diversity between these sites. Among the non-streptomycetes, 156 strains (19%) were considered as new taxa distributed into 21 genera belonging to 12 families. Interestingly, the isolation of actinomycetes from leaf-litter samples using the RC method proved to be the most efficient way to isolate new actinomycetes in Vietnam, especially the Micromonosporaceae species.

  15. Human impacts on functional and taxonomic homogenization of plateau fish assemblages in Yunnan, China

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    Guohuan Su

    2015-07-01

    Full Text Available Human activities and the consequent extinctions of native species and invasions of non-native species have been changing the composition of species assemblages worldwide. These anthropogenic impacts alter not only the richness of assemblages but also the biological dissimilarity among them. However, much of the research effort to date has focused on changes in taxonomic dissimilarity (i.e. accounting for species composition whether assessments of functional dissimilarity (i.e. accounting for the diversity of biological traits are much more scarce, despite revealing important complimentary information by accounting for changes in the diversity of biological traits. Here, we assess the temporal (1950s against 2000s changes in both taxonomic and functional dissimilarities of freshwater fish assemblages across lakes from the Yunnan Plateau in China. The Jaccard index to quantify the changes in both taxonomic and functional dissimilarity. We then partitioned dissimilarity to extract its turnover component and measured the changes in the contribution of turnover to dissimilarity. We found that functional and taxonomic homogenization occurred simultaneously. However, patterns between these two processes differed for some lakes. Taxonomic and functional homogenizations were stronger when the historical level of taxonomic dissimilarity among assemblages was high. The impact of extinctions of native species and invasions of non-native species on homogenization was otherwise complex to disentangle with no significant effect of any of the studied environmental factors. In agreement with other studies, our study proved that change in taxonomic dissimilarity cannot be used to predict changes in functional dissimilarity and, as an indicator of ecosystem functioning, functional dissimilarity should be used together with taxonomic dissimilarity to attain a more holistic understanding of human impacts on natural ecosystems.

  16. Taxonomic research priorities for the conservation of the South African flora

    Directory of Open Access Journals (Sweden)

    Lize von Staden

    2013-04-01

    Full Text Available Taxonomic revisions, monographs and floras are the most important, and often the only source of data for assessing the extinction risk of plants, with recent revisions contributing to more accurate assessments. The recently completed Red List of South African plants involved an overview of the taxonomic literature pertaining to the South African flora, providing an opportunity to identify critical gaps in taxonomic coverage. In this study we identified taxonomic research priorities for effective conservation of South African plants. Priorities were identified at genus level, according to time since last revision, level of endemism, collecting effort, proportion of taxa included in revisions, and specimen identification confidence. Although the results indicate that 62% of the flora has been recently revised, revisionary taxonomic output has declined drastically, particularly in the past 10 years. This decline is a result of a decrease in revisionary productivity per taxonomist and not a result of a decline in the number of working taxonomists. The family Aizoaceae is the top priority for taxonomic research with 55% of taxa in need of revision, followed by Hyacinthaceae with 34% of taxa not yet revised. Ericaceae, Euphorbiaceae, Rutaceae, Malvaceae, Asteraceae and Acanthaceae are also priorities with over 30% of taxa last revised before 1970. We recommend the reinstatement of the Flora of Southern Africa project in an online format in order to centralise South Africa's existing taxonomic information and reinvigorate revisionary taxonomic study. This project will allow South Africa to fulfil its commitments to the Convention on Biodiversity by achieving Target 1 of the Global Strategy for Plant Conservation.

  17. Illustrated Taxonomic Keys to Genera and Species of Mosquito Larvae of Korea. Part 2

    Science.gov (United States)

    1987-08-01

    Culicine Mosquito Larva Key to the Genera of Culicidae. . . Genus Anopheles . Genus Toxorhynchites . Genus Tripteroides. Genus Mansonia. . Genus...ILLUSTRATED TAXONOMIC KEYS TO GENERA AND SPECIES OF MOSQUITO LARVAE OF KOREA PART II DEPARTMENT OF THE ARMY BY 5TH PREVENTIVE MEDICINE UNIT...1987 4. TITLE AND SUBTITLE Illustrated Taxonomic Keys to Genera and Species of Mosquito Larvae of Korea. Part II 5a. CONTRACT NUMBER 5b. GRANT

  18. Avibase – a database system for managing and organizing taxonomic concepts

    Directory of Open Access Journals (Sweden)

    Denis Lepage

    2014-06-01

    Full Text Available Scientific names of biological entities offer an imperfect resolution of the concepts that they are intended to represent. Often they are labels applied to entities ranging from entire populations to individual specimens representing those populations, even though such names only unambiguously identify the type specimen to which they were originally attached. Thus the real-life referents of names are constantly changing as biological circumscriptions are redefined and thereby alter the sets of individuals bearing those names. This problem is compounded by other characteristics of names that make them ambiguous identifiers of biological concepts, including emendations, homonymy and synonymy. Taxonomic concepts have been proposed as a way to address issues related to scientific names, but they have yet to receive broad recognition or implementation. Some efforts have been made towards building systems that address these issues by cataloguing and organizing taxonomic concepts, but most are still in conceptual or proof-of-concept stage. We present the on-line database Avibase as one possible approach to organizing taxonomic concepts. Avibase has been successfully used to describe and organize 844,000 species-level and 705,000 subspecies-level taxonomic concepts across every major bird taxonomic checklist of the last 125 years. The use of taxonomic concepts in place of scientific names, coupled with efficient resolution services, is a major step toward addressing some of the main deficiencies in the current practices of scientific name dissemination and use.

  19. Global diversity and distribution of macrofungi

    Science.gov (United States)

    Gregory M. Mueller; John P. Schmit; Patrick R. Leacock; Bart Buyck; Joaquin Cifuentes; Dennis E. Desjardin; Roy E. Halling; Kurt Hjortstam; Teresa Iturriaga; Karl-Henrik Larsson; D. Jean Lodge; Tom W. May; David Minter; Mario Rajchenberg; Scott A. Redhead; Leif Ryvarden; James M. Trappe; Roy Watling; Qiuxin Wu

    2007-01-01

    Data on macrofungal diversity and distribution patterns were compiled for major geographical regions of the world. Macrofungi are defined here to include ascomycetes and basidiomycetes with large, easily observed spore-bearing structures that form above or below ground. Each coauthor either provided data on a particular taxonomic group of macrofungi or information on...

  20. Redescription of Phalotris labiomaculatus (Serpentes, Dipsadidae, Elapomorphini), with notes on the taxonomic boundaries within the nasutus group.

    Science.gov (United States)

    Hamdan, Breno; Da Silva, Nelson Jorge; Silva, Helder Lucio Rodrigues; Cintra, Carlos Eduardo D; De Lema, Thales

    2013-01-01

    Phalotris labiomaculatus Lema, 2002 was described based on a single specimen from Porto Franco, south of the Brazilian state of Maranhão, being rediscovered three years later in Mateiros, a municipality in the north of the state of Tocantins, attesting to its occurrence in the cerrado of both banks of the Tocantins River. The discovery of 28 new specimens from other localities during field expeditions (2009-2011) allowed a redescription of the species, adding new data on meristic and morpho-qualitative traits. These results enable a better diagnosis of intraspecific, ontogenetic and sexual variation, consolidating its taxonomic relationships with other species belonging to the nasutus group. The distribution map of P. labiomaculatus, as well as an identification key to the species of the natusus group, are provided. The type-locality is fixed to the municipality of Porto Franco, state of Maranhão.

  1. A multi-taxonomic indicator of acidification: isolating the effects of pH from other water-chemistry variables

    Energy Technology Data Exchange (ETDEWEB)

    Lonergan, S. P.; Rasmussen, J. B.

    1996-08-01

    A multi-taxonomic indicator of acidification was developed using the littoral benthic community. The objective was to isolate the effects of pH on this community from the effects of measured environmental co-variables. Multivariate direct gradient analysis was one of the tools used. The approach was then contrasted with the more general approach of identifying single- species indicators whose distributions indirectly reflect pH variations while ignoring known co-variables. Results indicated that many zoobenthic taxa, frequently cited as being negatively affected by acidification, reflect instead changes along a water-hardness gradient. The study indicated also that the management of pollutants cannot be based on laboratory studies of single-species responses; it is essential to include ecosystem-level information. 62 refs., 3 tabs., 3 figs.

  2. Gergithoides Schumacher, 1915 in Vietnam, with two new species, and taxonomic notes on the genus (Hemiptera: Fulgoromorpha: Issidae

    Directory of Open Access Journals (Sweden)

    Jérôme Constant

    2017-03-01

    Full Text Available Two new species of the genus Gergithoides Schumacher, 1915 (Issinae, Hemisphaeriini, G. gnezdilovi sp. nov. from Bidoup-Nui Ba National Park in Central Vietnam and G. nui sp. nov. from Pia-Oac National Park in North Vietnam, are described. These are the only species of the genus formally recorded from Vietnam to date. Habitus, details and male genitalia are illustrated and a distribution map is provided. Four females representing three or four additional species, known from females only, are mentioned and illustrated. Taxonomic and biogeographical updates based on a thorough review of the literature are proposed and discussed for G. carinatifrons Schumacher, 1915, G. rugulosus (Melichar, 1906 and G. undulatus Wang & Che, 2003.

  3. PROBIOTICS, PREBIOTICS AND SNYBIOTICS IN POULTRY MODE OF ACTION, LIMITATION, AND ACHIEVEMENTS

    Directory of Open Access Journals (Sweden)

    Agata DANKOWIAKOWSKA

    2013-03-01

    Full Text Available The withdrawal of antibiotic growth promoters from poultry industry have forced farmers to seek alternatives for the posing a risk factors of cross-resistance acquisition by harmful bacteria. A particular nuisance became salmonellosis and campylobacteriosis forcing to the elimination of whole poultry flocks as well as causing dangerous zoonotic diseases in humans. An excellent replacement for antibiotics have become the pro-, pre-and synbiotic substances which have a beneficial effect on the host organism through the development intensification of healthy intestinal microbial strains and the elimination of pathogenic strains. Such preparations may be administered both in the water spray as well as in feed. Excellent and promising method appears to be their injection directly into the egg air chamber in the 12th day of incubation. However, further studies are required to determine the appropriate doses as well as combinations of bioactive substances and to determine the optimal way for their delivery.

  4. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Directory of Open Access Journals (Sweden)

    María José Grande Burgos

    2014-12-01

    Full Text Available Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria. The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure.

  5. [Antifreeze glycoproteins in fishes: structure, mode of action and possible applications].

    Science.gov (United States)

    Wöhrmann, A

    1996-02-01

    Two types of antifreezes have been isolated from polar and northern temperate fishes so far. They are either glycopeptides or peptides. Whereas these proteins have only a very small effect on the melting temperature of ice, the temperature of these fish can fall to nearly 1 degree below the melting point before ice crystals grow. This phenomenon is called thermal hysteresis, in contrast to the normal colligative effect of solutes. All Antarctic notothenioids (perches) investigated so far have the typical antifreeze glycoproteins (AFGP) with the tripeptide Ala-Ala-Thr and the disaccharide Gal-GalNAc. In the Antarctic silverfish Pleuragramma antarcticum there could be found a novel GlcNAc containing antifreeze glycoprotein, the PAGP. The antifreezes not only lower the freezing temperature, but they also retard recrystallization on frozen storage. Antifreeze proteins thus could be useful for biotechnology and cryomedicine in the future. Since some are now synthesized chemically or by genetic engineering, they no longer have to be isolated from fish blood.

  6. Flavonols and fertilization in Petunia hybrida: localization and mode of action during pollen tube growth

    NARCIS (Netherlands)

    Ylstra, B.; Busscher, J.; Franken, J.; Hollman, P.C.H.; Mol, J.N.M.; Tunen, van A.J.

    1995-01-01

    Flavonols form an important class of flavonoids which serve an essential function during plant reproduction. Flavonoid biosynthesis is initiated by the enzyme chalcone synthase (CHS). A high abundance of flavonols and chs mRNA was demonstrated in male and female reproductive organs of Petunia

  7. Bioefficacy and mode-of-action of some limonoids of salannin group ...

    Indian Academy of Sciences (India)

    Unknown

    In nutritional assays, all three compounds reduced growth and consumption when fed to larvae without any effect on efficiency of conversion of ingested food (ECI), suggesting antifeedant activity alone. No toxicity was observed nor was there any significant affect on nutritional indices following topical appli- cation, further ...

  8. Characterization and mode of action of enzymes degrading galactan structures of arabinogalactans

    NARCIS (Netherlands)

    Vis, van de J.W.

    1994-01-01

    Agricultural biomass consisting mainly of cellulose, hemicellulose and lignin, is a renewable source of fuels and chemicals. An interesting option is enzymic conversion of biomass to readily usable material. To improve the overall economics of enzymic conversion of biomass not only

  9. Highly Selective Phosphatidylinositol 4-Kinase III beta Inhibitors and Structural Insight into Their Mode of Action

    Czech Academy of Sciences Publication Activity Database

    Mejdrová, Ivana; Chalupská, Dominika; Kögler, Martin; Šála, Michal; Plačková, Pavla; Bäumlová, Adriana; Hřebabecký, Hubert; Procházková, Eliška; Dejmek, Milan; Guillon, Rémi; Strunin, Dmytro; Weber, Jan; Lee, G.; Birkuš, G.; Mertlíková-Kaiserová, Helena; Bouřa, Evžen; Nencka, Radim

    2015-01-01

    Roč. 58, č. 9 (2015), s. 3767-3793 ISSN 0022-2623 R&D Projects: GA MŠk LO1302; GA ČR GA15-09310S; GA ČR GJ15-21030Y EU Projects: European Commission(XE) 333916 - STARPI4K Institutional support: RVO:61388963 Keywords : phosphatidylinositol 4-kinase III beta * broad-spectrum antiviral agents * positive-sense RNA viruses Subject RIV: CC - Organic Chemistry Impact factor: 5.589, year: 2015

  10. Elucidating antimalarial drug targets/mode-of-action by application of system biology technologies

    CSIR Research Space (South Africa)

    Becker, J

    2008-11-01

    Full Text Available . Eradication efforts are hampered by two major drawbacks-the absence of an effective vaccine coupled with the widespread occurrence of drug-resistant strains to frontline antimalarials and, of late, the emergence of resistance to current antimalarials of choice...

  11. Proceedings of the 2006 Toxicology and Risk Assessment Conference: Applying Mode of Action in Risk Assessment

    Science.gov (United States)

    2006-07-01

    neurophysiological function during and after exposure. The data suggest that the brain concentration of TCE at the moment of assessment is...Pharmacokinetics of Perchlorate and Its Effect on the Hypothalamus -Pituitary-Thyroid Axis in the Male Rat. Toxicol. Appl. Pharmacol. 182, 148- 159

  12. Genus Bupleurum: a review of its phytochemistry, pharmacology and modes of action.

    Science.gov (United States)

    Ashour, Mohamed L; Wink, Michael

    2011-03-01

    Radix Bupleuri represents one of the most successful and widely used herbal drugs in Asia for treatment of many diseases over the past 2000 years. Thorough studies have been carried out on many species of this genus and have generated immense data about the chemical composition and corresponding biological activity of extracts and isolated secondary metabolites. In this work, we review the chemistry and pharmacology of the genus Bupleurum and explore the relationships between the pharmacological effects and the chemical composition of these drugs. Early studies on the genus Bupleurum had focused only on the traditional uses of the plants in the treatment of inflammatory disorders and infectious diseases. After chemical profiling, several groups of secondary metabolites were characterized with relevant biological activity: triterpene saponins (saikosaponins), lignans, essential oils and polysaccharides. As a result, present interest is now focused on the bioactivity of the isolated triterpene saponins acting as immunomodulatory, anti-inflammatory and antiviral agents, as well as on the observed ant-iulcer activity of the polysaccharides and anti-proliferative activity of different lignans. Many saikosaponins exhibited very potent anti-inflammatory, hepatoprotective and immunomodulatory activities both in vivo and in vitro. Further investigations and screenings are required to explore other Bupleurum species, to evaluate the clinical safety and possible interactions with other drugs or herbs. Standardization of Bupleuri extracts is crucial for them being integrated into conventional medicine due to large chemical and biological variations between different species and varieties. © 2010 The Authors. JPP © 2010 Royal Pharmaceutical Society.

  13. Mode of Action (MOA) Assignment Classifications for Ecotoxicology: An Evaluation of approaches

    Science.gov (United States)

    The mode of toxic action (MOA) is recognized as a key determinant of chemical toxicity and as an alternative to chemical class-based predictive toxicity modeling. However, MOA classification has never been standardized in ecotoxicology, and a comprehensive comparison of classific...

  14. Riboflavin analogs as antiinfectives: occurrence, mode of action, metabolism and resistance.

    Science.gov (United States)

    Pedrolli, Danielle Biscaro; Jankowitsch, Frank; Schwarz, Julia; Langer, Simone; Nakanishi, Shinobu; Frei, Eva; Mack, Matthias

    2013-01-01

    Antimetabolites are molecules, which are structurally similar to molecules needed to carry out primary metabolic reactions.The inhibitory activity of an antimetabolite depends on its successful competition with the natural substrate, ligand, modulator or cofactor of a given biomolecule. Antimetabolites are indispensable as molecular tools in order to understand biological processes. Beyond that,antimetabolites have a large variety of applications in the pharmaceutical and food industries. The identification of the structural riboflavin(vitamin B2) analog roseoflavin in Streptomyces davawensis demonstrates that anti-vitamins/cofactor analogs may serve as lead structures for the development of novel antibiotics. The latter is supported by the recent finding that roseoflavin had a profound inhibiting effect on the growth and infectivity of the human bacterial pathogen Listeria monocytogenes at very low concentrations. Roseoflavin is studied in our laboratory as a model compound. We investigate the biosynthesis, the possible large-scale production, the metabolization,the mechanism of action and the resistance mechanism of the producer organism in order to pave the way for the structured analysis of other vitamin analogs yet to be discovered. These compounds hopefully will help to replenish the arsenal of antimicrobials urgently needed to fight multiresistant bacterial pathogens.

  15. Odorant Receptor Modulation: Ternary Paradigm for Mode of Action of Insect Repellents

    Science.gov (United States)

    2012-01-01

    attractants for Culex quinquefasciatus from fermented Bermuda grass infusions. J. Am. Mosq. Control Assoc. 8, 11e17. Mombaerts, P., 1999. Molecular...VUAA1 Mosquito Olfaction Agonist OrcoRAM a b s t r a c t The modulation of insect behavior for the purpose of controlling the spread of infectious...and hyperactivation will be fundamental to the development of novel strategies for the control of mosquito behavior. Published by Elsevier Ltd. 1

  16. Biogenic silver nanoparticles synthesized with rhamnogalacturonan gum: Antibacterial activity, cytotoxicity and its mode of action

    Directory of Open Access Journals (Sweden)

    Aruna Jyothi Kora

    2018-03-01

    Full Text Available Silver nanoparticles synthesized from gum kondagogu (5 nm were used to evaluate the antibacterial activity against Gram-positive and Gram-negative bacteria. To decipher the mode of antibacterial action of nanoparticles, a comprehensive study was carried out employing a variety of susceptibility assays: micro-broth dilution, antibiofilm activity, growth kinetics, cytoplasmic content leakage, membrane permeabilization, etc. The production of reactive oxygen species (ROS and cell surface damage during bacterial nanoparticle interaction were also demonstrated using dichlorodihydrofluorescein diacetate, N-acetylcysteine; and scanning electron microscopy and energy dispersive X-ray spectra. Further, the biocompatibility with HeLa cell line was also evaluated. Compared to earlier reports, the minimum inhibitory concentration values were lower by 3.2- and 16-folds for Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli strains, respectively. The minimum bactericidal concentration values were lower by 4 and 50-folds. Thus, the biogenic silver nanoparticles were found to be more potent bactericidal agents in terms of concentration. The nanoparticles exhibited significant antibiofilm activity against test strains at 2 μg mL−1, which can have implications in the treatment of drug resistant bacterial infections caused by biofilms. Growth curve in nanoparticle supplemented indicated a faster inhibition in Gram-negative bacteria as compared to Gram-positive. Treatment with nanoparticles caused cytoplasmic content leakage and membrane permeabilization in a dose dependent manner, an evidence for membrane damage. The observations noted in our study substantiated the association of ROS and membrane damage in the antibacterial action of silver nanoparticles. The promising antibacterial activity enables these nanoparticles as potential bactericidal material for various environmental and biomedical applications.

  17. Differences in Mode of Action of Cochinchinenin A and B on ...

    African Journals Online (AJOL)

    Purpose: To explore the mechanism of antagonistic interaction between cochinchinenin A and B in modulating tetrodotoxin-resistant (TTR-X) sodium currents. Methods: The time variation of the effects induced by cochinchinenin A and B on the TTX-R sodium currents in dorsal root ganglion (DRG) neurons of rats were ...

  18. Mode of Action Frameworks in Toxicity Testing and Chemical Risk Assessment

    NARCIS (Netherlands)

    Meek, B.

    2009-01-01

    Recently, legislative mandates worldwide are requiring systematic consideration of much larger numbers of chemicals. This necessitates more efficient and effective toxicity testing, as a basis to be more predictive in a risk assessment context. This in turn requires much more emphasis early in the

  19. Bioefficacy and mode-of-action of some limonoids of salannin group ...

    Indian Academy of Sciences (India)

    In nutritional assays, all three compounds reduced growth and consumption when fed to larvae without any effect on efficiency of conversion of ingested food (ECI), suggesting antifeedant activity alone. No toxicity was observed nor was there any significant affect on nutritional indices following topical application, further ...

  20. Antidepressant-like effects of aniracetam in aged rats and its mode of action.

    Science.gov (United States)

    Nakamura, K; Tanaka, Y

    2001-11-01

    Aniracetam has been reported to be efficacious for treating poststroke depression, but no studies that basically examined the antidepressive effects have been made. We aimed to test the antidepressant-like property of aniracetam in rats and to clarify the mechanisms of action through the interaction studies with some receptor antagonists. Antidepressant-like effects of aniracetam and various classes of compounds including different antidepressants were examined in a forced swim test with young (9 weeks old) and aged (25-30 months old) rats. Rats were exposed to a 5-min swim in a test session on day 2 following a 15-min swim in a training session on day 1, and immobility time during the period on day 2 was measured. The test compounds were administered subacutely (three doses over 2 days) or acutely (0.5 h before the testing). Standard antidepressants except for tandospirone significantly reduced immobility time in both young and aged rats. Aniracetam (10-100 mg/kg PO) failed to decrease immobility time in young rats, but it (100 mg/kg PO) significantly shortened immobility in aged rats, the effects of which were mainly mimicked by combined treatment of the metabolites, 2-pyrrolidinone and N-anisoyl-GABA. The effects of aniracetam was reversed completely by mecamylamine (10 mg/kg IP) or haloperidol (0.1 mg/kg IP) and slightly by ketanserin (1 m/kg IP) but was potentiated by scopolamine (0.03 mg/kg IP). These results indicate that aniracetam acts more effective when the forced swim stress-induced immobility is accompanied with brain dysfunction that occurs with aging. The antidepressant-like activity of aniracetam, which is probably due to the combined effects of 2-pyrrolidinone and N-anisoyl-GABA, may be mediated by mainly facilitating dopaminergic transmission (dopamine release and dopamine D2 receptor activation) through nicotinic acetylcholine receptor stimulation.

  1. PA01.33. Mode of action of medhya drugs: A review

    OpenAIRE

    Mehra, Bhawana; Dwivedi, K. N.

    2012-01-01

    Purpose: Memory is combination of power of acquisition (Grahan), retention (Dharan) and recollection (Smaran). Vata, pitta, and kapha are the three psychobiological dimensions (energy) or biological rhythms regulating the entire functioning of the human body. Pitta is responsible for understanding and attaining knowledge due to its Satva, Aashukari and Tikshna property. Vata is responsible for association of ideas. Kapha provides stability which is necessary for retention of memory. Several C...

  2. Understanding the Biosynthesis SF2575: A Potent Antitumor Compound With Novel Modes of Action

    Science.gov (United States)

    2009-09-01

    695 ([M+H]+ at m/z 696, RT = 23.2 min), in addition to the parent compound SF2575 ([M+H]+ at m/z 778, RT = 30.1 min) (Figure 3). The UV spectrum of...however OxyI was found to be uninvolved in the biosynthesis of oxytetracycline7. In an attempt to fully reconstitute the biosynthesis of 6...assay mixture was analyzed by LCMS. The result showed the presence the parent compound SF2575 and a second compound with mass corresponding to the

  3. Prion Protein-Specific Antibodies-Development, Modes of Action and Therapeutics Application

    Directory of Open Access Journals (Sweden)

    Tihana Lenac Rovis

    2014-10-01

    Full Text Available Prion diseases or Transmissible Spongiform Encephalopathies (TSEs are lethal neurodegenerative disorders involving the misfolding of the host encoded cellular prion protein, PrPC. This physiological form of the protein is expressed throughout the body, and it reaches the highest levels in the central nervous system where the pathology occurs. The conversion into the pathogenic isoform denoted as prion or PrPSc is the key event in prion disorders. Prominent candidates for the treatment of prion diseases are antibodies and their derivatives. Anti-PrPC antibodies are able to clear PrPSc from cell culture of infected cells. Furthermore, application of anti-PrPC antibodies suppresses prion replication in experimental animal models. Major drawbacks of immunotherapy are immune tolerance, the risks of neurotoxic side effects, limited ability of compounds to cross the blood-brain barrier and their unfavorable pharmacokinetic. The focus of this review is to recapitulate the current understanding of the molecular mechanisms for antibody mediated anti-prion activity. Although relevant for designing immunotherapeutic tools, the characterization of key antibody parameters shaping the molecular mechanism of the PrPC to PrPSc conversion remains elusive. Moreover, this review illustrates the various attempts towards the development of anti-PrP antibody compounds and discusses therapeutic candidates that modulate PrP expression.

  4. A fast kinetics study of the modes of action of some different radiosensitizers in bacteria

    International Nuclear Information System (INIS)

    Michael, B.D.; Harrop, H.A.; Maughan, R.L.; Patel, K.B.

    1978-01-01

    Using a fast mixing and irradiation technique, the gas explosion method, with Serratia marcescens, the decay of oxygen-dependent damage is found to consist of a fast and a slow stage, each of which is associated with a subcomponent of this damage. In the present work, the interactions of these components with radiosensitizers are examined. At low concentrations, O 2 , TAN (a nitroxyl) and misonidazole all preferentially sensitize the slow-stage damage. At higher concentrations, O 2 and TAN sensitize the fast-stage damage by a fixation reaction that competes with its repair; in contrast, misonidazole appears mainly to operate by reaction with an earlier, even shorter lived form of oxygen-dependent damage. (author)

  5. Mode of action of Bacillus licheniformis pectin methylesterase on highly methylesterified and acetylated pectins

    NARCIS (Netherlands)

    Remoroza, C.A.; Wagenknecht, M.; Buchholt, H.C.; Moerschbacher, B.M.; Gruppen, H.; Schols, H.A.

    2015-01-01

    A gene encoding a putative pectinesterase from Bacillus licheniformis DSM13 was cloned and expressed in Escherichia coli. The resulting recombinant enzyme (BliPME) was purified and characterized as a pectin methylesterase. The enzyme showed maximum activity at pH 8.0 and 50 °C. BliPME is able to

  6. The Mode of Action of Silver and Silver Halides Nanoparticles against Saccharomyces cerevisiae Cells

    Directory of Open Access Journals (Sweden)

    A. A. Kudrinskiy

    2014-01-01

    Full Text Available Silver and silver halides nanoparticles (NPs (Ag, AgCl, AgBr, and AgI capped with two different stabilizers (sodium citrate and nonionic surfactant Tween 80 were obtained via sodium borohydride reduction of silver nitrate in an aqueous solution. The effect of the biocidal action of as-prepared synthesized materials against yeast cells Saccharomyces cerevisiae was compared to the effect produced by silver nitrate and studied through the measurement of cell loss and kinetics of K+ efflux from the cells depending on concentration of silver. The results clearly indicate that the silver ions either remained in the dispersion of silver NPs and silver halides NPs after their synthesis or were generated afterwards by dissolving silver and silver halides particles playing a major part in the cytotoxic activity of NPs against yeast cells. It was also supposed that this activity most likely does not relate to the damage of cell membrane.

  7. Solubilization of lipids and membrane proteins into nanodiscs : Mode of action and applications of SMA copolymers

    NARCIS (Netherlands)

    Scheidelaar, S.

    2016-01-01

    Cell membranes separate the inside and outside of cells. Membrane proteins in the cell membrane control the traffic of molecules across the membrane and are therefore targets for a lot of drugs: about 50 % of all approved drugs target a membrane protein! Unfortunately, scientists only know little

  8. Structure and mode of action of cyclic lipopeptide pseudofactin II with divalent metal ions.

    Science.gov (United States)

    Janek, Tomasz; Rodrigues, Lígia R; Gudiña, Eduardo J; Czyżnikowska, Żaneta

    2016-10-01

    The interaction of natural lipopeptide pseudofactin II with a series of doubly charged metal cations was examined by matrix-assisted laser-desorption ionization-time of flight (MALDI-TOF) mass spectrometry and molecular modelling. The molecular modelling for metal-pseudofactin II provides information on the metal-peptide binding sites. Overall, Mg(2+), Ca(2+) and Zn(2+) favor the association with oxygen atoms spanning the peptide backbone, whereas Cu(2+) is coordinated by three nitrogens. Circular dichroism (CD) results confirmed that Zn(2+) and Cu(2+) can disrupt the secondary structure of pseudofactin II at high concentrations, while Ca(2+) and Mg(2+) did not essentially affect the structure of the lipopeptide. Interestingly, our results showed that the addition of Zn(2+) and Cu(2+) helped smaller micelles to form larger micellar aggregates. Since pseudofactin II binds metals, we tested whether this phenomena was somehow related to its antimicrobial activity against Staphylococcus epidermidis and Proteus mirabilis. We found that the antimicrobial effect of pseudofactin II was increased by supplementation of culture media with all tested divalent metal ions. Finally, by using Gram-positive and Gram-negative bacteria we showed that the higher antimicrobial activity of metal complexes of pseudofactin II is attributed to the disruption of the cytoplasmic membrane. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Relative value and mode of action of some fungicides used as seed disinfectants and protectants

    NARCIS (Netherlands)

    Samra, A.S.

    1956-01-01

    The first part of this paper deals with investigations at the Phytopathological Laboratory, Wageningen, into the control of Alternaria spp. (mainly A . raphani) on radish seed by chemicals. Organic mercury compounds proved better than thiram products and were more

  10. Tribendimidine: Mode of Action and nAChR Subtype Selectivity in Ascaris and Oesophagostomum

    Science.gov (United States)

    Robertson, Alan P.; Puttachary, Sreekanth; Buxton, Samuel K.; Martin, Richard J.

    2015-01-01

    The cholinergic class of anthelmintic drugs is used for the control of parasitic nematodes. One of this class of drugs, tribendimidine (a symmetrical diamidine derivative, of amidantel), was developed in China for use in humans in the mid-1980s. It has a broader-spectrum anthelmintic action against soil-transmitted helminthiasis than other cholinergic anthelmintics, and is effective against hookworm, pinworms, roundworms, and Strongyloides and flatworm of humans. Although molecular studies on C. elegans suggest that tribendimidine is a cholinergic agonist that is selective for the same nematode muscle nAChR as levamisole, no direct electrophysiological observations in nematode parasites have been made to test this hypothesis. Also the hypothesis that levamisole and tribendimine act on the same receptor, does not explain why tribendimidine is effective against some nematode parasites when levamisole is not. Here we examine the effects of tribendimidine on the electrophysiology and contraction of Ascaris suum body muscle and show that tribendimidine produces depolarization antagonized by the nicotinic antagonist mecamylamine, and that tribendimidine is an agonist of muscle nAChRs of parasitic nematodes. Further pharmacological characterization of the nAChRs activated by tribendimidine in our Ascaris muscle contraction assay shows that tribendimidine is not selective for the same receptor subtypes as levamisole, and that tribendimidine is more selective for the B-subtype than the L-subtype of nAChR. In addition, larval migration inhibition assays with levamisole-resistant Oesophagostomum dentatum isolates show that tribendimidine is as active on a levamisole-resistant isolate as on a levamisole-sensitive isolate, suggesting that the selectivity for levamisole and tribendimidine is not the same. It is concluded that tribendimidine can activate a different population of nematode parasite nAChRs than levamisole, and is more like bephenium. The different nAChR subtype selectivity of tribendimidine may explain why the spectrum of action of tribendimidine is different to that of other cholinergic anthelmintics like levamisole. PMID:25679515

  11. Differences in Mode of Action of Cochinchinenin A and B on ...

    African Journals Online (AJOL)

    HP

    Science and Technology (Grade SPF, SCXK. (Hubei) 2010-0007) were stunned by heavy blow on the head and decapitated. DRG were taken out and placed in 4 ℃ saturated. Dulbecco's Modified Eagle Medium (DMEM,. Sigma) solution gassed with 100 % oxygen. DRG neuron suspensions were obtained by.

  12. Etiology of bromate-induced cancer and possible modes of action-studies in Japan

    International Nuclear Information System (INIS)

    Umemura, Takashi; Kurokawa, Yuji

    2006-01-01

    Renal cell tumors were significantly increased in male and female rats given potassium bromate at 250 and 500 mg/L in drinking water. In at least one other study renal cell tumors were produced in male rats at 125 mg/L. Among male mice given 750 mg/L of potassium bromate, there were no significant differences in renal cell tumors between treated and control groups after 88 weeks on test. In oxidative DNA damage tests 8-oxodeoxyguanosine (8-oxodG also referred to as 8-OH-dG) was induced in DNA in the male rat kidney in 1 week, and in females after 3 weeks at 500 mg/L, and also in both male and female rats at 250 mg/L, but not at 125 mg/L. DNA adducts are considered to be an initial step in the carcinogenesis process, however, the administered doses are not always sufficient to cause mutations, possibly due to DNA repair. In the two-step rat renal carcinogenesis model using N-ethyl-N-hydroxyethylnitrosamine (EHEN) as initiator, promotion activity by potassium bromate was measured using the BrdU labeling index. The promoting activity of bromate in male rats was much greater and extended to doses as low as 60 mg/L in male rats, whereas in females the response was limited to 250 and 500 mg/L. Therefore, it was concluded that the mechanisms contributing to cancer in the male rat were more complex than in the female rat. The accumulation of α 2μ -globulin in the kidneys of male rats exposed to potassium bromate probably accounts for the greater labeling index in the male rat relative to the female rat. Accumulation of α 2μ -globulin as a result of treatment with chemicals is unique to the male rat and does contribute to carcinogenic responses. Neither humans nor female rats display this response. Nevertheless, bromate must be considered carcinogenic because of the response of the female rats. The better correlation between 8-oxodG formation and tumor response indicates that dose-response information from the female rat would be much more relevant to human risk assessment. The fact that an elevation of BrdU-LI in the kidney of the female rat is consistent with the possibility that cell proliferation observed in female rats resulted from oxidative stress and/or cytotoxic responses in the kidney. Therefore, oxidative stress is most likely the mechanism of interest for cancer risk in humans

  13. Antimicrobial compounds targeting Gram-negative bacteria in food: Their mode of action and combinational effects

    DEFF Research Database (Denmark)

    Hyldgaard, Morten

    2015-01-01

    they interact with bacterial cells to exert their mechanism of inhibition or killing. Furthermore, natural antimicrobials are often not potent enough as single compounds, and may cause unwanted sensory side-effects, which limit the quantities that can be applied to food. These problems might be circumvented......Gram-negative bacteria are a major cause of food spoilage and foodborne illnesses. However, finding effective solutions against Gram-negative bacteria are complicated because of increasing consumer demands for more natural, minimally processed, and fresh high quality food products without...... that isoeugenol permeabilized the cytoplasmic membrane, and probably inhibited intracellular esterases. We proposed that isoeugenol interacted with cytoplasmic membranes of E. coli in a reversible fashion, which destabilized membranes to become leaky in a non-disruptive detergent-like mechanism. In the third...

  14. SLAMF6 and 2B4: Roles and modes of action in normal immunity ...

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

    A functioning immune system is critical for successful treatment of cancer. Recent studies have shown an improvement of the immune response against cancer triggered by new drugs that block the function of certain types of receptors at the surface of immune cells. This project seeks to understand the role of two new ...

  15. Silage extracts used to study the mode of action of silage inoculants in ruminants

    Science.gov (United States)

    Alfalfa and two corn crops were ensiled with and without Lactobacillus plantarum MTD/1 silage inoculant and fermented for 4 or 60 d to assess the effect of the inoculant on in vitro rumen fermentation of the resulting silages. Water and 80% ethanol extracts of the silages with added glucose were als...

  16. Comparing the mode of action of intraocular lutein-based dyes with synthetic dyes.

    Science.gov (United States)

    Sousa-Martins, Diogo; Caseli, Luciano; Figueiredo, Mafalda C; Sa E Cunha, Claudia; Mota-Filipe, Helder; Souza-Lima, Acácio; Belfort, Rubens; Rodrigues, Eduardo; Maia, Mauricio

    2015-02-19

    To investigate and compare the mechanism by which lutein-based and synthetic intraocular dyes interact with their target membranes during ophthalmic surgeries. Surrogate membrane models were used in order to simulate the different intraocular membranes: internal limiting membrane (ILM), vitreous, anterior capsule (AC), and epiretinal membrane (ERM). Different lutein-based dyes, such as Phacodyne, Retidyne, Retidyne Plus, and Vitreodyne were tested, as well as Trypan Blue (TB), Indocyanine Green (ICG), Brilliant Blue (BB), and Triamcinolone Acetonide (TA). The interactions between the film components occurring at the air-water interface were investigated with surface pressure-area isotherms and polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS). With the exception of TA and ICG, none of the tested dyes revealed toxicity to the analyzed membranes. The interaction of TA with the vitreous model affected deeply the biointerface structure of the model. A significant condensation of the monolayer is noted when ICG contacted with ILM by the isotherms or even a solubilization of part of the monolayer toward the aqueous subphase. Retidyne Plus may provide the fluidization of the membrane, but maintains intact the structure of proteins present in the model. The present study demonstrates for the first time that lutein-based dyes interact through a physical mechanism of action with membrane models of structures present in human eye. On the other hand, the chemical interaction of synthetic dyes TA and ICG resulted in an alteration of the membrane models. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  17. Mode of Action of Membrane Perturbing Agents: Snake Venom Cardiotoxins and Phospholipases A

    Science.gov (United States)

    1989-07-15

    phospholipids preradiolabeled by feeding the cells 1.4C-fatty acids overnight. To develop potential prophylactic and therapeutic agents, pharmacological studies...PLAz neurotoxins. Experimental Methods: Materials. Vencm from 1 nAjA atra, CTX from Naja n9ja kaouthia venom (Lots 125F-4007), bee venom PLAz ( Apis ... mellifera ), melittin, B-bungarotoxin, Tris base, Hepes (4-(2-hydroxyethyl)-l-piperazineethanesulfonic acid), Mes (4- morpholineethanesulfonic acid), bovine

  18. Hydrogen peroxide induced cell death: One or two modes of action?

    Science.gov (United States)

    Uhl, Lionel; Gerstel, Audrey; Chabalier, Maialène; Dukan, Sam

    2015-12-01

    Imlay and Linn show that exposure of logarithmically growing Escherichia coli to hydrogen peroxide (H2O2) leads to two kinetically distinguishable modes of cell killing. Mode one killing is pronounced near 1 mM concentration of H2O2 and is caused by DNA damage, whereas mode-two killing requires higher concentration ([Formula: see text]). The second mode seems to be essentially due to damage to all macromolecules. This phenomenon has also been observed in Fenton in vitro systems with DNA nicking caused by hydroxyl radical ([Formula: see text]). To our knowledge, there is currently no mathematical model for predicting mode one killing in vitro or in vivo after H2O2 exposure. We propose a simple model, using Escherichia coli as a model organism and a set of ordinary differential equations. Using this model, we show that available iron and cell density, two factors potentially involved in ROS dynamics, play a major role in the prediction of the experimental results obtained by our team and in previous studies. Indeed the presence of the mode one killing is strongly related to those two parameters. To our knowledge, mode-one death has not previously been explained. Imlay and Linn (Imlay and Linn, 1986) suggested that perhaps the amount of the toxic species was reduced at high concentrations of H2O2 because hydroxyl (or other) radicals might be quenched directly by hydrogen peroxide with the concomitant formation of superoxide anion (a less toxic species). We demonstrate (mathematically and numerically) that free available iron decrease is necessary to explain mode one killing which cannot appear without it and that H2O2 quenching or consumption is not responsible for mode-one death. We are able to follow ROS concentration (particularly responsible for mode one killing) after exposure to H2O2. This model therefore allows us to understand two major parameters involved in the presence or not of the first killing mode.

  19. Cold atmospheric-pressure plasma and bacteria: understanding the mode of action using vibrational microspectroscopy

    International Nuclear Information System (INIS)

    Kartaschew, Konstantin; Mischo, Meike; Bründermann, Erik; Havenith, Martina; Baldus, Sabrina; Awakowicz, Peter

    2016-01-01

    Cold atmospheric-pressure plasma show promising antimicrobial effects, however the detailed biochemical mechanism of the bacterial inactivation is still unknown. We investigated, for the first time, plasma-treated Gram-positive Bacillus subtilis and Gram-negative Escherichia coli bacteria with Raman and infrared microspectroscopy. A dielectric barrier discharge was used as a plasma source. We were able to detect several plasma-induced chemical modifications, which suggest a pronounced oxidative effect on the cell envelope, cellular proteins and nucleotides as well as a generation of organic nitrates in the treated bacteria. Vibrationa