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Sample records for almidones resistentes sphagnum

  1. LOS ALMIDONES RESISTENTES Y LA SALUD

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    Carmen Carla Quiroga Ledezma

    2009-01-01

    Para una mejor comprensión de los almidones resistentes y su efecto en la salud se hizo una revisión bibliográfica de los trabajos publicados: estructura del almidón, tipos de modificaciones a la estructura del almidón, digestión del almidón, tipos de almidones, consecuencias fisiológicas del almidón resistente y tendencias futuras.

  2. Efecto de la concentración de almidones resistentes de la papa común (Solanum tuberosum) y criolla (Solanum phureja) sobre la digestibilidad de nutrientes, energía metabolizable e integridad del tracto gastrointestinal de pollos de engorde

    OpenAIRE

    Rodríguez Aguilar, Daniel Eduardo

    2013-01-01

    El almidón resistente retrogradado (AR3) de las variedades Pastusa (Solanum tuberosum grupo andigena) y Guaneña (Solanum tuberosum grupo phureja) fue evaluado como aditivo funcional con características similares a la fibra dietaria. En un primer experimento se comparó con manano oligosacáridos (MOS) a tres niveles de inclusión (0.5%, 1.0% y 1.5%) y un control sin suplementar, donde 600 pollos machos Ross de un día de edad fueron repartidos aleatoriamente a 10 tratamientos ex...

  3. La estructura resistente

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    Manterola, J.

    1968-09-01

    Full Text Available A structure, as a whole, consists of an organised set of material parts, whose structural significance depends both on their topological nature and on the external forces acting on them. This duality, that is typical of a structure, is related on the one hand to the structural forms that man can construct, and on the other to progressive adaptation of the structural topology to the external forces acting on it. The integrated study of the constructive process and of the theory of structures does not exhaust the problem of structures. The characteristics of the materials are still to be considered. The effect of these three factors on the cost depends on the dynamic evolution of these factors themselves: their importance being greater or smaller according to the evolutionary stage that is considered and the purpose of the structure. Furthermore, the structural significance of an object is influenced by the changes in the surrounding structural elements. Thus, a form, whose development might be determined strictly by structural motives at a given period, at another stage may no longer depend on structural factors. Hence structure is only a relative concept.En la estructura resistente, tomada como un todo, subyace una organización de elementos materiales, cuyo valor de posición viene condicionado tanto por las condiciones mecánicas de trabajo resistente que se establece entre ellas como por la posibilidad de manejar y colocar en su sitio el peso y volumen que determinan. Esta partición, contenido mismo de lo estructural, nos remite, por un lado, a las condiciones variables en que se concretan las posibilidades energéticas de la humanidad, y por otro, sitúa la estructura enfrentada a las acciones exteriores en una serie de etapas intermedias que para ser resistidas va a ser construida, lo que le proporciona la operatividad que reside en todo proceso de crecimiento. La integración del proceso constructivo y la teoría de lo resistente no agota

  4. PROPIEDADES FUNCIONALES DEL ALMIDON DE SAGU (Maranta arundinacea

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    CLEMENTE GRANADOS C

    Full Text Available El sagú (Maranta arundinacea cuyo rizoma es utilizado en algunas zonas de Colombia para la elaboración de productos destinados a la alimentación humana. Se extrajo el almidón y se determinaron las propiedades funcionales, los almidones presentaron alta capacidad de retención de agua% CRA (162,8% para el sagú, respecto al 226% de la yuca, un alto índice de absorción de lípidos, % I.A.L (51% para sagú, respecto al 82,25% del almidón de yuca. La temperatura de gelatinización esrelativamente baja (65-75°C a 10 minutos para sagú respecto al almidón de yuca con 70-75°C en 20 minutos, posee un alto porcentaje de amilopectina (77% para el almidón de sagú, en comparación con 83,3% para el almidón de yuca por tanto es un gel que no retrograda y forma una pasta estable. Por lo que se concluye que se puede usar como alternativa promisoria en la industria alimentaria.

  5. CARACTERIZACIÓN DE ALMIDONES DE YUCA NATIVOS Y MODIFICADOS PARA LA ELABORACIÓN DE EMPAQUES BIODEGRADABLES

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    MARIO ENRÍQUEZ C.

    Full Text Available Se estudiaron las propiedades fisicoquímicas de tres variedades de almidón de yuca (Manihot sculenta Crantz nativas y modificadas por hidroxipropilación.Las variedades estudiadas estaban nombradas con los códigos CM 7138-7, CUMBRE 3 y SM 707-17.Se determinó el grado de modificación de los almidones, se desarrollaron curvas de empastamiento de almidones, se obtuvieron propiedades térmicas mediante calorimetría de barrido diferencial (DSC y termogravimetría (TGA y se generaron espectros de absorción de los almidones por espectroscopía infrarroja con transformada de Fourier (FT-IR. Respecto a los almidones nativos, se identificaron diferencias entre éstos en las curvas de empastamiento, en la temperatura de transición vítrea (Tg y en la temperatura de fusión (Tm;en cuanto a los almidones modificados, se identificaron diferencias entre éstos en el grado de sustitución molar, en las curvas de empastamiento, en la Tg, la Tm y en los espectros obtenidos mediante FT-IR; en ambos casos estas diferencias fueron atribuidas al contenido de amilosa y amilopectina de los almidones. Respecto a las diferencias entre almidones nativos y modificados, el proceso de hidroxipropilación generó cambios en las propiedades estudiadas. Debido a su contenido de amilosa, menor viscosidad y Tg de su almidón modificado, la variedad CM 7138-7fue aquella que posiblemente presentó mejor potencial para ser empleada en la elaboración de empaques biodegradables.

  6. ANÁLISIS QUÍMICO Y DE ALMIDONES EN LA DETERMINACIÓN DE USOS DE TINAJAS ARQUEOLÓGICAS EN EL SITIO GUACHIMONTONES (MÉXICO (Starch and Chemical Analyses in Determining Uses of Archaeological Jars from the Guachimontones Site, Mexico

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    Miguel Ángel Novillo Verdugo

    2016-03-01

    Full Text Available La cerámica, por sus características constitutivas, es resistente al paso del tiempo y, por ende, es un recurso propicio para la generación de datos que permiten conocer el uso que desempeñaban los objetos arqueológicos. Así, se analizó un conjunto cerámico correspondiente a ocho tinajas registradas en el sitio arqueológico Guachimontones, por medio de análisis químicos y de almidones. Las pruebas aplicadas estuvieron enfocadas a reconocer residuos orgánicos e inorgánicos. Dichos análisis, que se realizaron en la cerámica, se complementan, pues la química representa una aproximación al uso particular de un artefacto, mientras que los almidones corroboraron dicho uso en prácticas alimentarias, medicinales o ceremoniales. ENGLISH: Ceramics, by their constituent features, are resistant to degradation over time and thus are suitable for generating data that provide insight into their use. Thus, chemical and starch analyses were conducted on a set of eight ceramic jars registered at the archaeological site of Guachimontones. The tests applied were chosen in order to identify evidence of organic and inorganic waste. These analyses are complimentary because chemistry indicates the particular use of an artifact while starches corroborate their use in such things as food, medicinal, or ceremonial practices.

  7. Caracterización funcional de almidones nativos obtenidos de papas (Solanum phureja nativas peruanas

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    P. Martínez

    2015-01-01

    Full Text Available Existen muchas variedades de papas nativas cultivadas en diferentes localidades del Perú, generalmente para el auto consumo del agricultor. Sin embargo, la posibilidad de su uso comercial ha originado este trabajo con el fin de darles un valor agregado. Para evaluar la posibilidad de uso del almidón nativo proveniente de estas papas, como ingrediente en la industria alimentaria, se planteó como objetivo determinar las propiedades funcionales de almidones obtenidos de papas nativas procedentes de Pampacorral (Cusco, Perú: Puka Ambrosio (PA, Combe (CO, Perwanita (PER, Kalis qero (KQ, Qello virondos (QEV, Yana churos (YACH, Pitikiña (PI, Yana kusi (YAKU y Solischa (SOL. Con este fin se prepararon geles con el almidón nativo, por dispersión y calentamiento. El poder de hinchamiento, el índice de absorción y la solubilidad mostraron estar correlacionados con el incremento de la temperatura. A 90 °C, el almidón de la variedad PI mostró los mayores valores de poder de hinchamiento (28,47%, capacidad de absorción de agua (22,70 y solubilidad (20,24%. La menor sinéresis, a 4 °C, la presentaron los almidones de las variedades CO y YACH, 3,8 y 4,6; respectivamente. Los geles de almidón de todas las variedades mostraron un comportamiento pseudoplástico (n G”.

  8. pH Lowering Ability of Sphagnum.

    Science.gov (United States)

    Glime, Janice M.; Li, Yenhung

    1998-01-01

    States that the ecological role of Sphagnum species in peatlands is enormous. Presents a cation exchange experiment and background information on the characteristics and economic importance of Sphagnum. Contains 42 references. (DDR)

  9. Caracterización estructural y térmica de almidones provenientes de diferentes variedades de papa

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    Oscar Hernando Pardo C

    2013-12-01

    Full Text Available Utilizando análisis fisicoquímico, estructural y térmico, se evaluaron almidones de las variedades de papa Parda Pastusa (P, Tuquerreña (T, ICA Huila (IH, ICA Puracé (IP, ICA Única (IU, Criolla Latina (C y R-12 (R, cultivadas en el departamento de Boyacá, Colombia. En cada una de ellas se determinaron los contenidos de ceniza y proteína siguiendo métodos de la AOAC, humedad utilizando un analizador, estructura cristalina mediante difracción de rayos-X (DRX y propiedades térmicas utilizando calorimetría diferencial de barrido (DSC. Se encontraron diferencias significativas (P < 0.05 entre los contenidos de humedad en almidones. El almidón de la variedad IU presentó el mayor contenido de ceniza y el de la variedad T, el menor. Los difractogramas mostraron para todas las variedades patrones de cristalinidad tipo B; no obstante el almidón de las variedades IP, P, IU, T y IH presentó un patrón más cristalino que el de las variedades C y R. Los termogramas de los almidones mostraron el primer y segundo pico endotérmico, entre 123 y 163 J/g y entre 141 y 213.3 J/g, respectivamente, para las variedades IP, P, IU, T y IH; mientras que para los almidones de las variedades C y R estos valores fueron entre 68 y 77 J/g y entre 334 y 358 J/g, respectivamente.

  10. Residuos de almidones y el uso de plantas durante el holoceno medio en el cauca medio (colombia)

    OpenAIRE

    Aceituno, Francisco; Lalinde, Veronica

    2012-01-01

    En este artículo se presentan datos de almidones que sugieren el uso de plantas porgrupos forrajeros que ocuparon el río San Eugenio (Cauca medio) durante la primeramitad del Holoceno medio. Se logró recuperar una gran cantidad de granos dealmidón (325) de instrumentos de molienda (manos y placas) procedentes de nivelesprecerámicos del sitio arqueológico La Pochola. Los datos indican el aprovechamientode plantas ricas en carbohidratos, entre las que se encuentra una variedad de Phaseolus(silv...

  11. Eindrapportage onderzoek naar ontwikkeling Verticillium resistente Acer

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    Hiemstra, J.A.; Sluis, van der B.J.

    2013-01-01

    Dit project is de laatste fase in het onderzoek naar de ontwikkeling van Verticillium-resistente Acer platanoides (Noorse esdoorn) onderstammen wat in 1993 van start ging op het toenmalige CPRO-DLO (nu PRI) met grootschalige selectie-experimenten. PPO-Bomen heeft vanaf 1999 onderzoek gedaan naar

  12. Ecophysiological adaptations of coexisting Sphagnum mosses

    OpenAIRE

    HÁJEK, Tomáš

    2008-01-01

    I studied ecological and physiological adaptations of peat misses (Sphagnum species) coexisting along the environmental gradients in mires. Production, decomposition, water relations, desiccation tolerance and nutrient economy of Sphagnum species were evaluates along the hummock-hollow gradient of water table, while the light adaptations were assessed in an open and forested mire

  13. Evaporation from a sphagnum moss surface

    Science.gov (United States)

    D.S. Nichols; J.M. Brown

    1980-01-01

    Peat cores, 45 cm in diameter, were collected from a sphagnum bog in northern Minnesota, and used to measure the effects of different temperatures and water levels on evaporation from a sphagnum moss surface in a growth chamber. Under all conditions, evaporation from the moss surface was greater than that from a free-water surface. Evaporation from the moss increased...

  14. Restoration techniques for Sphagnum-dominated peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Ferland, C.; Rochefort, L. [Laval University, Sainte-Foy, PQ (Canada). Department of Phytology

    1997-07-01

    After peat harvesting, peat mosses do not usually recolonize the abandoned site. The purpose of this study is to develop techniques for restoring peatlands. Sphagnum diaspores from natural peatlands were introduced to exploited peatlands. The influence of microrelief, of planting companion species with the Sphagnum, and of light phosphorus fertilization on establishment of a peat moss carpet are examined. The results show that Sphagnum diaspores can be reintroduced on bare peat surfaces. The restoration method is combined with techniques to improve substrata moisture conditions, such as creation of surface roughness and the use of companion plant species. 32 refs., 6 figs., 3 tabs.

  15. Sphagnum farming on cut-over bog in NW Germany: Long-term studies on Sphagnum growth

    OpenAIRE

    G. Gaudig; M. Krebs; H. Joosten

    2017-01-01

    Sphagnum farming allows sustainable and climate-friendly land use on bogs while producing a renewable substitute for peat in horticultural growing media. We studied Sphagnum productivity on an experimental Sphagnum culture established on a cut-over bog in Germany with strongly humified peat at the surface. Preparation of the site included levelling of the peat surface, construction of an irrigation system, spreading of Sphagnum papillosum fragments, covering them with straw, and finally rewet...

  16. Sphagnum moss disperses spores with vortex rings.

    Science.gov (United States)

    Whitaker, Dwight L; Edwards, Joan

    2010-07-23

    Sphagnum spores, which have low terminal velocities, are carried by turbulent wind currents to establish colonies many kilometers away. However, spores that are easily kept aloft are also rapidly decelerated in still air; thus, dispersal range depends strongly on release height. Vascular plants grow tall to lift spores into sufficient wind currents for dispersal, but nonvascular plants such as Sphagnum cannot grow sufficiently high. High-speed videos show that exploding capsules of Sphagnum generate vortex rings to efficiently carry spores high enough to be dispersed by turbulent air currents. Spores launched ballistically at similar speeds through still air would travel a few millimeters and not easily reach turbulent air. Vortex rings are used by animals; here, we report vortex rings generated by plants.

  17. Nitrogen deposition does not enhance Sphagnum decomposition.

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    Manninen, S; Kivimäki, S; Leith, I D; Leeson, S R; Sheppard, L J

    2016-11-15

    Long-term additions of nitrogen (N) to peatlands have altered bryophyte growth, species dominance, N content in peat and peat water, and often resulted in enhanced Sphagnum decomposition rate. However, these results have mainly been derived from experiments in which N was applied as ammonium nitrate (NH4NO3), neglecting the fact that in polluted areas, wet deposition may be dominated either by NO3(-) or NH4(+). We studied effects of elevated wet deposition of NO3(-) vs. NH4(+) alone (8 or 56kgNha(-1)yr(-1) over and above the background of 8kgNha(-1)yr(-1) for 5 to 11years) or combined with phosphorus (P) and potassium (K) on Sphagnum quality for decomposers, mass loss, and associated changes in hummock pore water in an ombrotrophic bog (Whim). Adding N, especially as NH4(+), increased N concentration in Sphagnum, but did not enhance mass loss from Sphagnum. Mass loss seemed to depend mainly on moss species and climatic factors. Only high applications of N affected hummock pore water chemistry, which varied considerably over time. Overall, C and N cycling in this N treated bog appeared to be decoupled. We conclude that moss species, seasonal and annual variation in climatic factors, direct negative effects of N (NH4(+) toxicity) on Sphagnum production, and indirect effects (increase in pH and changes in plant species dominance under elevated NO3(-) alone and with PK) drive Sphagnum decomposition and hummock C and N dynamics at Whim. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Growth of sphagnum: methods of measurement

    Energy Technology Data Exchange (ETDEWEB)

    Clymo, R S

    1970-01-01

    The results presented here show that the growth of sphagnum is at least comparable with other communities from the same area. It seems desirable to know more about the field microenvironment and about the response of the plants. It is not possible, for example, to account satisfactorily for such obvious features of bog topography as hummocks and pools.

  19. Sphagnum bogs of Kelantan, Peninsular Malaysia

    NARCIS (Netherlands)

    Yao, T.L.; Kamarudin, S.; Chew, M.Y.; Kiew, R.

    2009-01-01

    Sphagnum bog, a unique plant community for Peninsular Malaysia was encountered on Padang Ragut, Kelantan. Its topographical features and flora are described, and compared with padang and upper montane floras. It is postulated that the community is derived from upper montane forest and is the result

  20. [Methanotrophic bacteria of acid sphagnum bogs].

    Science.gov (United States)

    Dedysh, S N

    2002-01-01

    Acid sphagnum bogs cover a considerable part of the territory of Russia and are an important natural source of biogenic methane, which is formed in their anaerobic layers. A considerable portion of this methane is consumed in the aerobic part of the bog profile by acidophilic methanotrophic bacteria, which comprise the methane filter of sphagnum bogs and decrease CH4 emission to the atmosphere. For a long time, these bacteria escaped isolation, which became possible only after the elucidation of the optimal conditions of their functioning in situ: pH 4.5 to 5.5; temperature, from 15 to 20 degrees C; and low salt concentration in the solution. Reproduction of these conditions and rejection of earlier used media with a high content of biogenic elements allowed methanotrophic bacteria of two new genera and species--Methylocella palustris and Methylocapsa acidophila--to be isolated from the peat of sphagnum bogs of the northern part of European Russia and West Siberia. These bacteria are well adapted to the conditions in cold, acid, oligotrophic sphagnum bogs. They grow in a pH range of 4.2-7.5 with an optimum at 5.0-5.5, prefer moderate temperatures (15-25 degrees C) and media with a low content of mineral salts (200-500 mg/l), and are capable of active nitrogen fixation. Design of fluorescently labeled 16S rRNA-targeted oligonucleotide probes for the detection of Methylocella palustris and Methylocapsa acidophila and their application to the analysis of sphagnum peat samples showed that these bacteria represent dominant populations of methanotrophs with a density of 10(5)-10(6) cells/g peat. In addition to Methylocella and Methylocapsa populations, one more abundant population of methanotrophs was revealed (10(6) cells/g peat), which were phylogenetically close to the genus Methylocystis.

  1. Sphagnum growth and ecophysiology during mire succession.

    Science.gov (United States)

    Laine, Anna M; Juurola, Eija; Hájek, Tomáš; Tuittila, Eeva-Stiina

    2011-12-01

    Sphagnum mosses are widespread in areas where mires exist and constitute a globally important carbon sink. Their ecophysiology is known to be related to the water level, but very little is currently known about the successional trend in Sphagnum. We hypothesized that moss species follow the known vascular plant growth strategy along the successional gradient (i.e., decrease in production and maximal photosynthesis while succession proceeds). To address this hypothesis, we studied links between the growth and related ecophysiological processes of Sphagnum mosses from a time-since-initiation chronosequence of five wetlands. We quantified the rates of increase in biomass and length of different Sphagnum species in relation to their CO(2) assimilation rates, their photosynthetic light reaction efficiencies, and their physiological states, as measured by the chlorophyll fluorescence method. In agreement with our hypothesis, increase in biomass and CO(2) exchange rate of Sphagnum mosses decreased along the successional gradient, following the tactics of more intensely studied vascular plants. Mosses at the young and old ends of the chronosequence showed indications of downregulation, measured as a low ratio between variable and maximum fluorescence (F(v)/F(m)). Our study divided the species into three groups; pioneer species, hollow species, and ombrotrophic hummock formers. The pioneer species S. fimbriatum is a ruderal plant that occurred at the first sites along the chronosequence, which were characterized by low stress but high disturbance. Hollow species are competitive plants that occurred at sites with low stress and low disturbance (i.e., in the wet depressions in the middle and at the old end of the chronosequence). Ombrotrophic hummock species are stress-tolerant plants that occurred at sites with high stress and low disturbance (i.e., at the old end of the chronosequence). The three groups along the mire successional gradient appeared to be somewhat analogous

  2. Symbiosis revisited : Phosphorus and acid buffering stimulate N2 fixation but not Sphagnum growth

    NARCIS (Netherlands)

    Van Den Elzen, Eva; Kox, Martine A R; Harpenslager, Sarah F.; Hensgens, Geert; Fritz, Christian; Jetten, Mike S M; Ettwig, Katharina F.; Lamers, Leon P M

    2017-01-01

    In pristine Sphagnum-dominated peatlands, (di)nitrogen (N2) fixing (diazotrophic) microbial communities associated with Sphagnum mosses contribute substantially to the total nitrogen input, increasing carbon sequestration. The rates of symbiotic nitrogen fixation reported for Sphagnum peatlands,

  3. Sphagnum farming on cut-over bog in NW Germany: Long-term studies on Sphagnum growth

    Directory of Open Access Journals (Sweden)

    G. Gaudig

    2017-05-01

    Full Text Available Sphagnum farming allows sustainable and climate-friendly land use on bogs while producing a renewable substitute for peat in horticultural growing media. We studied Sphagnum productivity on an experimental Sphagnum culture established on a cut-over bog in Germany with strongly humified peat at the surface. Preparation of the site included levelling of the peat surface, construction of an irrigation system, spreading of Sphagnum papillosum fragments, covering them with straw, and finally rewetting. Provided there was an adequate (95 % initial cover of Sphagnum fragments, the most relevant variables for Sphagnum productivity were found to be water supply and regular mowing of vascular plants. As long as sufficient water was supplied, the dry biomass accumulation of the established Sphagnum lawn remained high, reaching 3.7 t ha-1 yr-1 between 2007 and 2011. Annual dry Sphagnum biomass productivity over the period 2010–2011 was up to 6.9 t ha-1. During periods when high water table could not be maintained, substantial decomposition of the previously accumulated biomass occurred. After nine years the net accumulated dry mass per hectare was on average 19.5 t of pure Sphagnum and 0.7 t of subsurface vascular-plant biomass. Nitrogen deposition in the study region is apparently sufficient to support fast Sphagnum growth, whereas phosphorus and potassium may be limiting.

  4. Comprobaciones resistentes de elementos constructivos de tierra

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    Estrada, Enrique

    1986-11-01

    Full Text Available This work has the purpose to compare, by means of different tests on adobe bricks and masonry, the obtained resistant properties and those of other similar works carried out in countries having a wide tradition and knowledge about earth as construction material. Elements (adobe bricks and blocks have been tested to compression and bending, and masonry made of those elements to compression and diagonal compression.El presente trabajo pretende comparar, por medio de distintos ensayos sobre elementos y fábricas de mampostería de tierra, las propiedades resistentes obtenidas con las de otros trabajos similares realizados en países con dilatada tradición y conocimiento de la tierra como material de construcción. Se han ensayado elementos (adobes y bloques a compresión y flexotracción y fábricas formadas por conjuntos de los mismos a compresión y a compresión diagonal.

  5. Sphagnum farming in Germany – a review of progress

    OpenAIRE

    G. Gaudig; F. Fengler; M. Krebs; A. Prager; J. Schulz; S. Wichmann; H. Joosten

    2014-01-01

    In ombrotrophic, nutrient-poor peatlands, the cultivation of peatmoss (Sphagnum spp.) is a promising paludiculture option. Since 2001 we have been studying peatmoss cultivation (‘Sphagnum farming’) in greenhouse and field experiments, paying special attention to propagation, propagule storage, establishment, productivity and regeneration. Our studies show that Sphagnum farming in Germany may provide a sustainable high-quality alternative to fossil white peat as a raw material for horticultural...

  6. Sphagnum farming in Germany – a review of progress

    Directory of Open Access Journals (Sweden)

    G. Gaudig

    2014-02-01

    Full Text Available In ombrotrophic, nutrient-poor peatlands, the cultivation of peatmoss (Sphagnum spp. is a promising paludiculture option. Since 2001 we have been studying peatmoss cultivation (‘Sphagnum farming’ in greenhouse and field experiments, paying special attention to propagation, propagule storage, establishment, productivity and regeneration. Our studies show that Sphagnum farming in Germany may provide a sustainable high-quality alternative to fossil white peat as a raw material for horticultural growing media. Sphagnum farming is, furthermore, a climate-friendly and sustainable land use option for abandoned cut-over bogs and degraded bog grassland.

  7. AMIDO RESISTENTE EM FARINHAS DE BANANA VERDE

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    Dayana Portes RAMOS

    2010-03-01

    Full Text Available

    Este trabalho teve por objetivo avaliar o teor de amido resistente (AR em farinhas de banana verde produzidas a partir de treze genótipos de bananeira. Para a produção da farinha foram separadas a 1ª, 3ª e 5ª pencas de cada genótipo, na qual cada penca correspondeu a uma repetição. Os frutos de cada penca no estádio 1 (casca completamente verde de maturação foram descascados manualmente, cortados em fatias circulares de 0,5 cm e desidratados em estufa com circulação de ar a 40ºC por 48 horas, sendo em seguida moídos. A análise de AR consistiu em um processo enzimático, calculando-se o conteúdo final pela concentração de glicose liberada. Os resultados foram submetidos à análise estatística e mostraram diferenças significativas para o teor de AR nas farinhas obtidas dos genótipos de bananeira, sendo que a farinha com maior teor de AR foi a produzida a partir do cultivar ‘Nam’ (40,25% e a menor pelo híbrido ‘Fhia 01’ (10,01%. Pode-se concluir que o conteúdo de AR varia em relação ao genótipo utilizado para a confecção da farinha e que a banana pode ser uma boa opção de estudo de alimento funcional.

  8. A comparative study of lipids in Sphagnum species

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Baas, M.; Pancost, R.D.; Geel, B. van

    2000-01-01

    The free lipid compositions of twelve species of Sphagnum were determined by capillary gas chromatography/mass spectrometry as part of a study to identify characteristic lipids for Sphagnum in peat bogs. Complex mixtures of lipids, comprised of C28 C29 sterols, C30 triterpenoids, C16 C30 fatty

  9. The Sphagnum microbiome: new insights from an ancient plant lineage

    Science.gov (United States)

    Joel E. Kostka; David J. Weston; Jennifer B. Glass; Erik A. Lilleskov; A. Jonathan Shaw; Merritt Turetsky

    2016-01-01

    Peat mosses of the genus Sphagnum play a major role in global carbon storage and dominate many northern peatland ecosystems, which are currently being subjected to some of the most rapid climate changes on Earth.Arapidly expanding database indicates that a diverse community of microorganisms is intimately associated with Sphagnum...

  10. Organellar phylogenomics of an emerging model system: Sphagnum (peatmoss).

    Science.gov (United States)

    Jonathan Shaw, A; Devos, Nicolas; Liu, Yang; Cox, Cymon J; Goffinet, Bernard; Flatberg, Kjell Ivar; Shaw, Blanka

    2016-08-01

    Sphagnum-dominated peatlands contain approx. 30 % of the terrestrial carbon pool in the form of partially decomposed plant material (peat), and, as a consequence, Sphagnum is currently a focus of studies on biogeochemistry and control of global climate. Sphagnum species differ in ecologically important traits that scale up to impact ecosystem function, and sequencing of the genome from selected Sphagnum species is currently underway. As an emerging model system, these resources for Sphagnum will facilitate linking nucleotide variation to plant functional traits, and through those traits to ecosystem processes. A solid phylogenetic framework for Sphagnum is crucial to comparative analyses of species-specific traits, but relationships among major clades within Sphagnum have been recalcitrant to resolution because the genus underwent a rapid radiation. Herein a well-supported hypothesis for phylogenetic relationships among major clades within Sphagnum based on organellar genome sequences (plastid, mitochondrial) is provided. We obtained nucleotide sequences (273 753 nucleotides in total) from the two organellar genomes from 38 species (including three outgroups). Phylogenetic analyses were conducted using a variety of methods applied to nucleotide and amino acid sequences. The Sphagnum phylogeny was rooted with sequences from the related Sphagnopsida genera, Eosphagnum and Flatbergium Phylogenetic analyses of the data converge on the following subgeneric relationships: (Rigida (((Subsecunda) (Cuspidata)) ((Sphagnum) (Acutifolia))). All relationships were strongly supported. Species in the two major clades (i.e. Subsecunda + Cuspidata and Sphagnum + Acutifolia), which include >90 % of all Sphagnum species, differ in ecological niches and these differences correlate with other functional traits that impact biogeochemical cycling. Mitochondrial intron presence/absence are variable among species and genera of the Sphagnopsida. Two new nomenclatural combinations are made

  11. Greenhouse gas balance of an establishing Sphagnum culture on a former bog grassland in Germany

    OpenAIRE

    A. Günther; G. Jurasinski; K. Albrecht; G. Gaudig; M. Krebs; S. Glatzel

    2017-01-01

    The cultivation of Sphagnum mosses on re-wetted peat bogs for use in horticulture is a new land use strategy. We provide the first greenhouse gas balances for a field-scale Sphagnum farming experiment on former bog grassland, in its establishment phase. Over two years we used closed chambers to make measurements of GHG exchange on production strips of Sphagnum palustre L. and Sphagnum papillosum Lindb. and on irrigation ditches. Methane fluxes of both Sphagnum species showed a significant dec...

  12. The Sphagnum microbiome: new insights from an ancient plant lineage.

    Science.gov (United States)

    Kostka, Joel E; Weston, David J; Glass, Jennifer B; Lilleskov, Erik A; Shaw, A Jonathan; Turetsky, Merritt R

    2016-07-01

    57 I. 57 II. 58 III. 59 IV. 59 V. 61 VI. 62 63 References 63 SUMMARY: Peat mosses of the genus Sphagnum play a major role in global carbon storage and dominate many northern peatland ecosystems, which are currently being subjected to some of the most rapid climate changes on Earth. A rapidly expanding database indicates that a diverse community of microorganisms is intimately associated with Sphagnum, inhabiting the tissues and surface of the plant. Here we summarize the current state of knowledge regarding the Sphagnum microbiome and provide a perspective for future research directions. Although the majority of the microbiome remains uncultivated and its metabolic capabilities uncharacterized, prokaryotes and fungi have the potential to act as mutualists, symbionts, or antagonists of Sphagnum. For example, methanotrophic and nitrogen-fixing bacteria may benefit the plant host by providing up to 20-30% of Sphagnum carbon and nitrogen, respectively. Next-generation sequencing approaches have enabled the detailed characterization of microbiome community composition in peat mosses. However, as with other ecologically or economically important plants, our knowledge of Sphagnum-microbiome associations is in its infancy. In order to attain a predictive understanding of the role of the microbiome in Sphagnum productivity and ecosystem function, the mechanisms of plant-microbiome interactions and the metabolic potential of constituent microbial populations must be revealed. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  13. Studies on sphagnum peat. III. A quantitative study on the carbohydrate constituents of sphagnum mosses and sphagnum peat

    Energy Technology Data Exchange (ETDEWEB)

    Theander, O

    1954-01-01

    A qualitative and a quantitative investigation of the carbohydrates in two sphagnum mosses and five samples of sphagnum peat of different age and degree of huminosity has been performed. The two mosses investigated showed no significant differences. Samples of very different age but with the same degree of physical huminosity were very similar, indicating that the chief changes occur at the top of the bog and/or are determined by the conditions at the start of the humification. The total amount of carbohydrates was about 90% of the organic material in the mosses and about 65% and 35% in peats with a degree of huminosity of 3-4 and 6-7 respectively. Of the constituent sugars, fructose which occurred in the mosses, was completely absent in the peat. Another sugar, which occurs in nature as a furanoside, arabinose, disappeared almost completely during the humification. The uronic acids and galactose decreased faster, while ylose and glucose decreased at about the same rate as the total carbohydrates. Mannose and probably also rhamnose are the most stable components and accumulate during the humification. The polysaccharides in mosses and peat seem to constitute a very complex mixture. The presence of a fructan in the living moss, of a polyuronide (pectin) and a large amount of more complex polysaccharides built up of galactose, xylose, rhamnose and uronic acids is indicated. The glucose, the most important constituent, probably occurs chiefly as cellulose, the presence of which has been demonstrated by other workers. Finally the behaviour of mannose during the humification indicates the presence of a stable mannan. There is no evidence of polysaccharides formed by microorganisms in the peat.

  14. Vortex rings from Sphagnum moss capsules

    Science.gov (United States)

    Whitaker, Dwight; Strassman, Sam; Cha, Jung; Chang, Emily; Guo, Xinyi; Edwards, Joan

    2010-11-01

    The capsules of Sphagnum moss use vortex rings to disperse spores to suitable habitats many kilometers away. Vortex rings are created by the sudden release of pressurized air when the capsule ruptures, and are an efficient way to carry the small spores with low terminal velocities to heights where they can be carried by turbulent wind currents. We will present our computational model of these explosions, which are carried out using a 2-D large eddy simulation (LES) on FLUENT. Our simulations can reproduce the observed motion of the spore clouds observed from moss capsules with high-speed videos, and we will discuss the roles of bursting pressure, cap mass, and capsule morphology on the formation and quality of vortex rings created by this plant.

  15. In vitro decomposition of Sphagnum by some microfungi resembles white rot of wood.

    Science.gov (United States)

    Rice, Adrianne V; Tsuneda, Akihiko; Currah, Randolph S

    2006-06-01

    The abilities of some ascomycetes (Myxotrichaceae) from a Sphagnum bog in Alberta to degrade cellulose, phenolics, and Sphagnum tissue were compared with those of two basidiomycetes. Most Myxotrichaceae degraded cellulose and tannic acid, and removed cell-wall components simultaneously from Sphagnum tissues, whereas the basidiomycetes degraded cellulose and insoluble phenolics, and preferentially removed the polyphenolic matrix from Sphagnum cell walls. Mass losses from Sphagnum varied from up to 50% for some ascomycetes to a maximum of 35% for the basidiomycetes. The decomposition of Sphagnum by the Myxotrichaceae was analogous to the white rot of wood and indicates that these fungi have the potential to cause significant mineralization of carbon in bogs.

  16. High nitrogen availability reduces polyphenol content in Sphagnum peat.

    Science.gov (United States)

    Bragazza, Luca; Freeman, Chris

    2007-05-15

    Peat mosses of the genus Sphagnum constitute the bulk of living and dead biomass in bogs. These plants contain peculiar polyphenols which hamper litter peat decomposition through their inhibitory activity on microbial breakdown. In the light of the increasing availability of biologically active nitrogen in natural ecosystems, litter derived from Sphagnum mosses is an ideal substrate to test the potential effects of increased atmospheric nitrogen deposition on polyphenol content in litter peat. To this aim, we measured total nitrogen and soluble polyphenol concentration in Sphagnum litter peat collected in 11 European bogs under a chronic gradient of atmospheric nitrogen deposition. Our results demonstrate that increasing nitrogen concentration in Sphagnum litter, as a consequence of increased exogenous nitrogen availability, is accompanied by a decreasing concentration of polyphenols. This inverse relationship is consistent with reports that in Sphagnum mosses, polyphenol and protein biosynthesis compete for the same precursor. Our observation of modified Sphagnum litter chemistry under chronic nitrogen eutrophication has implications in the context of the global carbon balance, because a lower content of decay-inhibiting polyphenols would accelerate litter peat decomposition.

  17. Tecidos moles (não resistentes: como se fossilizam?

    Directory of Open Access Journals (Sweden)

    Silvia Regina Gobbo

    2015-06-01

    Full Text Available A preservação de tecidos moles (não resistentes desperta atenção pela qualidade dos fósseis preservados, e pela raridade. Este trabalho faz ampla revisão do assunto, desfaz alguns dos mitos correntes sobre fossilização destes materiais, como anaerobiose e soterramento rápido, bem como assinala a relevância do papel da replicagem de estruturas morfológicas por colônias microbianas. No âmbito dos fatores que influenciam a preservação de tecidos não resistentes estão pH, processos de decomposição, soterramento rápido e mineralização rápida por meio de carbonatos ou fosfatos. É possível citar exemplos de fácies sedimentares nas quais há preservação de tecidos não resistentes, como os folhelhos pirobetuminosos, calcários litográficos, folhelhos e diatomitos. Destaca-se o papel das colônias microbianas, tanto na forma de microesferas, como aquelas não-esferulíticas. Os três mitos principais que se procurou desfazer no artigo são: (1 a presença de oxigênio; (2 o soterramento rápido e (3 as colônias microbianas.

  18. Efecto de la acetilación sobre las propiedades funcionales y nutricionales de almidones de haba (VICIA FABA

    Directory of Open Access Journals (Sweden)

    Constanza López

    2011-03-01

    Full Text Available Se analizaron algunas propiedades funcionales del almidón de haba (Vicia faba, con dos niveles de proteína -12,89% y 4,41%-, obtenido por fraccionamiento por vía húmeda de las semillas secas. Se comparan el secado en rodillos y la liofilización como métodos para deshidratar la muestra, así como las propiedades funcionales del almidón antes y después de acetilarlo con anhídrido acético. También se investigaron ciertas propiedades de interés nutricional con el fin de observar la influencia de la modificación química en la biodisponibilidad del almidón de haba. Se realizó la determinación de almidón total, almidón resistente por retrogradación (AR3, almidón disponible y la velocidad de hidrólisis enzimática en el almidón nativo y en el modificado.

  19. Desiccation tolerance of Sphagnum revisited: a puzzle resolved.

    Science.gov (United States)

    Hájek, T; Vicherová, E

    2014-07-01

    As ecosystem engineers, Sphagnum mosses control their surroundings through water retention, acidification and peat accumulation. Because water retention avoids desiccation, sphagna are generally intolerant to drought; however, the literature on Sphagnum desiccation tolerance (DT) provides puzzling results, indicating the inducible nature of their DT. To test this, various Sphagnum species and other mesic bryophytes were hardened to drought by (i) slow drying; (ii) ABA application and (iii) chilling or frost. DT tolerance was assessed as recovery of chlorophyll fluorescence parameters after severe desiccation. We monitored the seasonal course of DT in bog bryophytes. Under laboratory conditions, following initial de-hardening, untreated Sphagnum shoots lacked DT; however, DT was induced by all hardening treatments except chilling, notably by slow drying, and in Sphagnum species of the section Cuspidata. In the field, sphagna in hollows and lawns developed DT several times during the growing season, responding to reduced precipitation and a lowered water table. Hummock and aquatic species developed DT only in late autumn, probably as a response to frost. Sphagnum protonemata failed to develop DT; hence, desiccation may limit Sphagnum establishment in drier habitats with suitable substrate chemistry. Desiccation avoiders among sphagna form compact hummocks or live submerged; thus, they do not develop DT in the field, lacking the initial desiccation experience, which is frequent in hollow and lawn habitats. We confirmed the morpho-physiological trade-off: in contrast to typical hollow sphagna, hummock species invest more resources in water retention (desiccation avoidance), while they have a lower ability to develop physiological DT. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Sphagnum moss as a growing media constituent: some effects of harvesting, processing and storage

    OpenAIRE

    S. Kumar

    2017-01-01

    The Sphagnum material used in horticulture so far has been harvested manually, and most of the available data about Sphagnum properties have been obtained from this material. A question that remains unanswered is how changes during harvesting and processing, as well as the use of mechanical methods, affect the important properties of Sphagnum moss as a growing media constituent. Some of the effects have been evaluated in Sphagnum farming projects in Germany during the past ten years, and are ...

  1. The importance of groundwater-derived carbon dioxide in the restoration of small Sphagnum bogs

    NARCIS (Netherlands)

    Patberg, Wouter; Baaijens, Gert Jan; Smolders, Alfons J. P.; Grootjans, Ab P.; Elzenga, J. Theo M.

    Essential for successful bog restoration is the reestablishment of Sphagnum mosses. High carbon dioxide availability has been shown to be of great importance for the growth of Sphagnum mosses. In well-developed Sphagnum bogs large amounts of carbon dioxide are produced by (an)aerobic decomposition

  2. Biophysical drivers of seasonal variability in Sphagnum gross primary production in a northern temperate bog

    Science.gov (United States)

    Walker, Anthony P.; Carter, Kelsey R.; Gu, Lianhong; Hanson, Paul J.; Malhotra, Avni; Norby, Richard J.; Sebestyen, Stephen D.; Wullschleger, Stan D.; Weston, David J.

    2017-05-01

    Sphagnum mosses are the keystone species of peatland ecosystems. With rapid rates of climate change occurring in high latitudes, vast reservoirs of carbon accumulated over millennia in peatland ecosystems are potentially vulnerable to rising temperature and changing precipitation. We investigate the seasonal drivers of Sphagnum gross primary production (GPP)—the entry point of carbon into wetland ecosystems. Continuous flux measurements and flux partitioning show a seasonal cycle of Sphagnum GPP that peaked in the late summer, well after the peak in photosynthetically active radiation. Wavelet analysis showed that water table height was the key driver of weekly variation in Sphagnum GPP in the early summer and that temperature was the primary driver of GPP in the late summer and autumn. Flux partitioning and a process-based model of Sphagnum photosynthesis demonstrated the likelihood of seasonally dynamic maximum rates of photosynthesis and a logistic relationship between the water table and photosynthesizing tissue area when the water table was at the Sphagnum surface. The model also suggested that variability in internal resistance to CO2 transport, a function of Sphagnum water content, had minimal effect on GPP. To accurately model Sphagnum GPP, we recommend the following: (1) understanding seasonal photosynthetic trait variation and its triggers in Sphagnum; (2) characterizing the interaction of Sphagnum photosynthesizing tissue area with water table height; (3) modeling Sphagnum as a "soil" layer for consistent simulation of water dynamics; and (4) measurement of Sphagnum "canopy" properties: extinction coefficient (k), clumping (Ω), and maximum stem area index (SAI).

  3. Evolution of niche preference in Sphagnum peat mosses.

    Science.gov (United States)

    Johnson, Matthew G; Granath, Gustaf; Tahvanainen, Teemu; Pouliot, Remy; Stenøien, Hans K; Rochefort, Line; Rydin, Håkan; Shaw, A Jonathan

    2015-01-01

    Peat mosses (Sphagnum) are ecosystem engineers-species in boreal peatlands simultaneously create and inhabit narrow habitat preferences along two microhabitat gradients: an ionic gradient and a hydrological hummock-hollow gradient. In this article, we demonstrate the connections between microhabitat preference and phylogeny in Sphagnum. Using a dataset of 39 species of Sphagnum, with an 18-locus DNA alignment and an ecological dataset encompassing three large published studies, we tested for phylogenetic signal and within-genus changes in evolutionary rate of eight niche descriptors and two multivariate niche gradients. We find little to no evidence for phylogenetic signal in most component descriptors of the ionic gradient, but interspecific variation along the hummock-hollow gradient shows considerable phylogenetic signal. We find support for a change in the rate of niche evolution within the genus-the hummock-forming subgenus Acutifolia has evolved along the multivariate hummock-hollow gradient faster than the hollow-inhabiting subgenus Cuspidata. Because peat mosses themselves create some of the ecological gradients constituting their own habitats, the classic microtopography of Sphagnum-dominated peatlands is maintained by evolutionary constraints and the biological properties of related Sphagnum species. The patterns of phylogenetic signal observed here will instruct future study on the role of functional traits in peatland growth and reconstruction. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  4. Detection, isolation, and characterization of acidophilic methanotrophs from Sphagnum mosses.

    Science.gov (United States)

    Kip, Nardy; Ouyang, Wenjing; van Winden, Julia; Raghoebarsing, Ashna; van Niftrik, Laura; Pol, Arjan; Pan, Yao; Bodrossy, Levente; van Donselaar, Elly G; Reichart, Gert-Jan; Jetten, Mike S M; Damsté, Jaap S Sinninghe; Op den Camp, Huub J M

    2011-08-15

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphaproteobacterial methanotrophs was found. With Sphagnum mosses as the inoculum, alpha- and gammaproteobacterial acidophilic methanotrophs were isolated using established and newly designed media. The 16S rRNA, pmoA, pxmA, and mmoX gene sequences showed that the alphaproteobacterial isolates belonged to the Methylocystis and Methylosinus genera. The Methylosinus species isolated are the first acid-tolerant members of this genus. Of the acidophilic gammaproteobacterial strains isolated, strain M5 was affiliated with the Methylomonas genus, and the other strain, M200, may represent a novel genus, most closely related to the genera Methylosoma and Methylovulum. So far, no acidophilic or acid-tolerant methanotrophs in the Gammaproteobacteria class are known. All strains showed the typical features of either type I or II methanotrophs and are, to the best of our knowledge, the first isolated (acidophilic or acid-tolerant) methanotrophs from Sphagnum mosses.

  5. Contrasting phylogeographic patterns in Sphagnum fimbriatum and Sphagnum squarrosum (Bryophyta, Sphagnopsida) in Europe.

    Science.gov (United States)

    Szövényi, Péter; Hock, Zsófia; Urmi, Edwin; Schneller, Jakob J

    2006-01-01

    The chloroplast phylogeography of two peat mosses (Sphagnum fimbriatum and Sphagnum squarrosum) with similar distributions but different life history characteristics was investigated in Europe. Our main aim was to test whether similar distributions reflect similar phylogeographic and phylodemographic processes. Accessions covering the European distributions of the species were collected and approx. 2000 bp of the chloroplast genome of each species was sequenced. Maximum parsimony, statistical parsimony and phylodemographic analyses were used to address the question of whether these species with similar distributions show evidence of similar phylogeographic and phylodemographic processes. The chloroplast haplotypes of the currently spreading species S. fimbriatum showed strong geographic structure, whereas those of S. squarrosum, which has stable historical population sizes, showed only very weak geographic affinity and were widely distributed. We hypothesize that S. fimbriatum survived the last glaciations along the Atlantic coast of Europe, whereas S. squarrosum had numerous, scattered refugia in Europe. The dominance of one haplotype of S. fimbriatum across almost all of Europe suggests rapid colonization after the last glacial maximum. We hypothesize that high colonizing ability is an inherent characteristic of the species and its recent expansion in Europe is a response to climate change.

  6. Antibacterial activity of sphagnum acid and other phenolic compounds found in Sphagnum papillosum against food-borne bacteria.

    Science.gov (United States)

    Mellegård, H; Stalheim, T; Hormazabal, V; Granum, P E; Hardy, S P

    2009-07-01

    To identify the phenolic compounds in the leaves of Sphagnum papillosum and examine their antibacterial activity at pH appropriate for the undissociated forms. Bacterial counts of overnight cultures showed that whilst growth of Staphylococcus aureus 50084 was impaired in the presence of milled leaves, the phenol-free fraction of holocellulose of S. papillosum had no bacteriostatic effect. Liquid chromatography-mass spectrometry analysis of an acetone-methanol extract of the leaves detected eight phenolic compounds. Antibacterial activity of the four dominating phenols specific to Sphagnum leaves, when assessed in vitro as minimal inhibitory concentrations (MICs), were generally >2.5 mg ml(-1). MIC values of the Sphagnum-specific compound 'sphagnum acid' [p-hydroxy-beta-(carboxymethyl)-cinnamic acid] were >5 mg ml(-1). No synergistic or antagonistic effects of the four dominating phenols were detected in plate assays. Sphagnum-derived phenolics exhibit antibacterial activity in vitro only at concentrations far in excess of those found in the leaves. We have both identified the phenolic compounds in S. papillosum and assessed their antibacterial activity. Our data indicate that phenolic compounds in isolation are not potent antibacterial agents and we question their potency against food-borne pathogens.

  7. Swift recovery of Sphagnum nutrient concentrations after excess supply.

    Science.gov (United States)

    Limpens, Juul; Heijmans, Monique M P D

    2008-08-01

    Although numerous studies have addressed the effects of increased N deposition on nutrient-poor environments such as raised bogs, few studies have dealt with to what extent, and on what time-scale, reductions in atmospheric N supply would lead to recovery of the ecosystems in question. Since a considerable part of the negative effects of elevated N deposition on raised bogs can be related to an imbalance in tissue nutrient concentrations of the dominant peat-former Sphagnum, changes in Sphagnum nutrient concentration after excess N supply may be used as an early indicator of ecosystem response. This study focuses on the N and P concentrations of Sphagnum magellanicum and Sphagnum fallax before, during and after a factorial fertilization experiment with N and P in two small peatlands subject to a background bulk deposition of 2 g N m(-2) year(-1). Three years of adding N (4.0 g N m(-2) year(-1)) increased the N concentration, and adding P (0.3 g P m(-2) year(-1)) increased the P concentration in Sphagnum relative to the control treatment at both sites. Fifteen months after the nutrient additions had ceased, N concentrations were similar to the control whereas P concentrations, although strongly reduced, were still slightly elevated. The changes in the N and P concentrations were accompanied by changes in the distribution of nutrients over the capitulum and the stem and were congruent with changes in translocation. Adding N reduced the stem P concentration, whereas adding P reduced the stem N concentration in favor of the capitulum. Sphagnum nutrient concentrations quickly respond to reductions in excess nutrient supply, indicating that a management policy aimed at reducing atmospheric nutrient input to bogs can yield results within a few years.

  8. Experiments on the effect of sphagnum on the pH of salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Williams, K T; Thompson, T G

    1936-01-01

    Addition of sphagnum to salt solutions produced marked increases in the concentrations of the hydrogen ions, as measured both electrometrically and colorimetrically. The greater the concentration of the salt solution, the greater the increase in hydrogen ion concentration upon the addition of sphagnum. With a given salt concentration, the hydrogen ion concentration increased with increase in quantity of sphagnum added. The divalent cations produced greater increases in the hydrogen concentration than the monovalent cations for equal weights of sphagnum. Divalent anions, while showing an increase in hydrogen ions, upon the addition of sphagnum were far less effective in increasing the hydrogen ion concentrations. Sphagnum may be a useful reagent for regulating the acidity of salt solutions for many types of scientific work. It seems probable that the adsorption of metallic and hydroxyl ions explains, at least in part, the acidity of the water of sphagnum bogs.

  9. The role of Sphagnum mosses in the methane cycling of a boreal mire.

    Science.gov (United States)

    Larmola, Tuula; Tuittila, Eeva-Stiina; Tiirola, Marja; Nykänen, Hannu; Martikainen, Pertti J; Yrjälä, Kim; Tuomivirta, Tero; Fritze, Hannu

    2010-08-01

    Peatlands are a major natural source of atmospheric methane (CH4). Emissions from Sphagnum-dominated mires are lower than those measured from other mire types. This observation may partly be due to methanotrophic (i.e., methane-consuming) bacteria associated with Sphagnum. Twenty-three of the 41 Sphagnum species in Finland can be found in the peatland at Lakkasuo. To better understand the Sphagnum-methanotroph system, we tested the following hypotheses: (1) all these Sphagnum species support methanotrophic bacteria; (2) water level is the key environmental determinant for differences in methanotrophy across habitats; (3) under dry conditions, Sphagnum species will not host methanotrophic bacteria; and (4) methanotrophs can move from one Sphagnum shoot to another in an aquatic environment. To address hypotheses 1 and 2, we measured the water table and CH4 oxidation for all Sphagnum species at Lakkasuo in 1-5 replicates for each species. Using this systematic approach, we included Sphagnum spp. with narrow and broad ecological tolerances. To estimate the potential contribution of CH4 to moss carbon, we measured the uptake of delta13C supplied as CH4 or as carbon dioxide dissolved in water. To test hypotheses 2-4, we transplanted inactive moss patches to active sites and measured their methanotroph communities before and after transplantation. All 23 Sphagnum species showed methanotrophic activity, confirming hypothesis 1. We found that water level was the key environmental factor regulating methanotrophy in Sphagnum (hypothesis 2). Mosses that previously exhibited no CH4 oxidation became active when transplanted to an environment in which the microbes in the control mosses were actively oxidizing CH4 (hypothesis 4). Newly active transplants possessed a Methylocystis signature also found in the control Sphagnum spp. Inactive transplants also supported a Methylocystis signature in common with active transplants and control mosses, which rejects hypothesis 3. Our

  10. Peatmoss (Sphagnum) diversification associated with Miocene Northern Hemisphere climatic cooling?

    Science.gov (United States)

    Shaw, A Jonathan; Devos, Nicolas; Cox, Cymon J; Boles, Sandra B; Shaw, Blanka; Buchanan, Alex M; Cave, Lynette; Seppelt, Rodney

    2010-06-01

    Global climate changes sometimes spark biological radiations that can feed back to effect significant ecological impacts. Northern Hemisphere peatlands dominated by living and dead peatmosses (Sphagnum) harbor almost 30% of the global soil carbon pool and have functioned as a net carbon sink throughout the Holocene, and probably since the late Tertiary. Before that time, northern latitudes were dominated by tropical and temperate plant groups and ecosystems. Phylogenetic analyses of mosses (phylum Bryophyta) based on nucleotide sequences from the plastid, mitochondrial, and nuclear genomes indicate that most species of Sphagnum are of recent origin (ca. Sphagnum species are not only well-adapted to boreal peatlands, they create the conditions that promote development of peatlands. The recent radiation that gave rise to extant diversity of peatmosses is temporally associated with Miocene climatic cooling in the Northern Hemisphere. The evolution of Sphagnum has had profound influences on global biogeochemistry because of the unique biochemical, physiological, and morphological features of these plants, both while alive and after death. 2010 Elsevier Inc. All rights reserved.

  11. Sphagnum distribution patterns along environmental gradients in Bulgaria

    Czech Academy of Sciences Publication Activity Database

    Hájková, Petra; Hájek, Michal

    2007-01-01

    Roč. 29, č. 1 (2007), s. 18-26 ISSN 0373-6687 Grant - others:GA AV ČR(CZ) KJB6163302 Institutional research plan: CEZ:AV0Z60050516 Keywords : Sphagnum * the Balkans * ecology Subject RIV: EF - Botanics Impact factor: 1.218, year: 2007

  12. The disappearance of Sphagnum imbricatum from Butterburn Flow, UK

    NARCIS (Netherlands)

    McClymont, E.L.; Mauquoy, D.; Yeloff, D.; Broekens, P.; van Geel, B.; Charman, D.J.; Pancost, R.D.; Chambers, F.M.; Evershed, R.P.

    2008-01-01

    The disappearance of the previously abundant moss species Sphagnum imbricatum has been investigated at Butterburn Flow, northern England, using organic geochemical, elemental, macrofossil, pollen and testate amoebae analyses. Variations in the assemblage of peat-forming plants were tracked using the

  13. Revival of Dutch Sphagnum bogs: a reasonable perspective?

    NARCIS (Netherlands)

    Tomassen, H.B.M.

    2004-01-01

    In the Netherlands, the area of raised bogs has been virtually lost during two millennia of human impact. Much effort has been invested in rewetting these cut-over bogs, but the recovery of Sphagnum-dominated vegetation often failed. The work presented includes research on the role of hydrochemistry

  14. Evaluación de estructuras de muros resistentes

    Directory of Open Access Journals (Sweden)

    Lewicki, Bohdan

    1988-12-01

    Full Text Available The author of this article, who is one of the main International personalities in the field of the structural engineering, point out the importance of intuition as a component of the creative capacity of the engineer, as well as its necessity within de evaluation process of structures. The article includes also some Indications about the general principles on reliability of masonry structures.

    El autor del presente artículo, una de las máximas autoridades mundiales en el campo de la Ingeniería estructural, señala la importancia de la intuición como componente de la capacidad creadora del ingeniero y su necesidad en el proceso de evaluación de las estructuras. En el artículo se dan también unas indicaciones referentes a principios generales sobre fiabilidad de las estructuras de muros resistentes.

  15. The Sphagnum microbiome supports bog ecosystem functioning under extreme conditions.

    Science.gov (United States)

    Bragina, Anastasia; Oberauner-Wappis, Lisa; Zachow, Christin; Halwachs, Bettina; Thallinger, Gerhard G; Müller, Henry; Berg, Gabriele

    2014-09-01

    Sphagnum-dominated bogs represent a unique yet widely distributed type of terrestrial ecosystem and strongly contribute to global biosphere functioning. Sphagnum is colonized by highly diverse microbial communities, but less is known about their function. We identified a high functional diversity within the Sphagnum microbiome applying an Illumina-based metagenomic approach followed by de novo assembly and MG-RAST annotation. An interenvironmental comparison revealed that the Sphagnum microbiome harbours specific genetic features that distinguish it significantly from microbiomes of higher plants and peat soils. The differential traits especially support ecosystem functioning by a symbiotic lifestyle under poikilohydric and ombrotrophic conditions. To realise a plasticity-stability balance, we found abundant subsystems responsible to cope with oxidative and drought stresses, to exchange (mobile) genetic elements, and genes that encode for resistance to detrimental environmental factors, repair and self-controlling mechanisms. Multiple microbe-microbe and plant-microbe interactions were also found to play a crucial role as indicated by diverse genes necessary for biofilm formation, interaction via quorum sensing and nutrient exchange. A high proportion of genes involved in nitrogen cycle and recycling of organic material supported the role of bacteria for nutrient supply. 16S rDNA analysis indicated a higher structural diversity than that which had been previously detected using PCR-dependent techniques. Altogether, the diverse Sphagnum microbiome has the ability to support the life of the host plant and the entire ecosystem under changing environmental conditions. Beyond this, the moss microbiome presents a promising bio-resource for environmental biotechnology - with respect to novel enzymes or stress-protecting bacteria. © 2014 John Wiley & Sons Ltd.

  16. Effects of elevated atmospheric CO2 concentration and increased nitrogen deposition on growth and chemical composition of ombrotrophic Sphagnum balticum and oligo-mesotrophic Sphagnum papillosum

    NARCIS (Netherlands)

    Van der Heijden, E; Jauhiainen, J; Silvola, J; Vasander, H; Kuiper, PJC

    2000-01-01

    The ombrotrophic Sphagnum balticum (Russ.) C. Jens. and the oligo-mesotrophic Sphagnum papillosum Lindb. were grown at ambient (360 mu l l(-1)) and at elevated (720 mu l l(-1)) atmospheric CO2 concentrations and at different nitrogen deposition rates, varying between 0 and 30kg N ha(-1) yr(-1), The

  17. Preferential degradation of polyphenols from Sphagnum – 4-Isopropenylphenol as a proxy for past hydrological conditions in Sphagnum-dominated peat

    NARCIS (Netherlands)

    Schellekens, J.; Bindler, R.; Martinez Cortizas, A.; McClymont, E.L.; Abbott, G.D.; Biester, H.; Pontevedra Pombal, X.; Buurman, P.

    2015-01-01

    The net accumulation of remains of Sphagnum spp. is fundamental to the development of many peatlands. The effect of polyphenols from Sphagnum on decomposition processes is frequently cited but has barely been studied. The central area of the Rödmossamyran peatland (Sweden) is an open lawn that

  18. Efecto de la Adición de dos Tipos de Almidones en las Propiedades Texturales de Queso Análogo / Effect of the Addition of Two Types of Starch in the Textural Properties of Analogue Cheese

    Directory of Open Access Journals (Sweden)

    Jacqueline Agudelo Chaparro

    2014-12-01

    Full Text Available Resumen. Se estudió el efecto que tienen dos tipos de almidónmodificado, maíz ceroso y papa, en las propiedades texturalesde un queso análogo con fibra prebiótica soluble. Se elaboraronquesos semiblandos, con humedad de 48%, reemplazando el10% de proteína por los almidones modificados, dando lugar atres tratamientos: Formulación control (FC, formulación maízceroso (FMC y formulación papa (FP. Se observó que la adiciónde los almidones afecta significativamente (P<0,05 la dureza, laadhesividad, la gomosidad, la elasticidad y la masticabilidad delproducto. /  Abstract. The effect they have two types of modified starch (waxycorn and potato in the textural properties of an analogue cheesewas studied. Semi-soft cheeses were made with 48% moisture,replacing the 10% protein by modified starches, resulting in threetreatments: Control formulation (CF, waxy corn formulation(WCF and potato formulation (PF. The study allowed note thatthe addition of starches significantly affect (P<0.05 the hardness,adhesiveness, gumminess, elasticity and chewiness of the product

  19. Sphagnum moss as a growing media constituent: some effects of harvesting, processing and storage

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2017-09-01

    Full Text Available The Sphagnum material used in horticulture so far has been harvested manually, and most of the available data about Sphagnum properties have been obtained from this material. A question that remains unanswered is how changes during harvesting and processing, as well as the use of mechanical methods, affect the important properties of Sphagnum moss as a growing media constituent. Some of the effects have been evaluated in Sphagnum farming projects in Germany during the past ten years, and are described in this article. Different possibilities for drying, screening and cleaning the Sphagnum material are described. The results obtained indicate that Sphagnum moss can be dried and processed using mechanical methods without negative impacts on its quality as a growing media constituent.

  20. Arquitectura sismo-resistente: respuesta morfológica

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    Giulani, Hugo

    1994-12-01

    Full Text Available In the previous reports (1 and (2 we raised the question of the necessity to develop an Earthquake-Resistant Architecture which would make the integral solution of the seismic problem in buildings possible. We established the grounds, objectives, basic principles and methodology for defining the guidelines to be followed in making the architectural design and structural earthquake-resistant design compatible. The present report brings the proposal of an architectural response from the morphological point of view, allowing us to reach an adequate final form which consists of eliminating all the incompatibilities produced by the seismic demands and determining factors, in other words, we search for an architectural design which, owing to its very morphology, is able to satisfy the said conditions; an "Adequate Final Form" which in itself avoids the bothersome guidelines for making the structural and architectural designs compatible, transforming them into morphological responses to each seismic determining factor.

    En informes anteriores (1 y (2 planteamos la necesidad de desarrollar una Arquitectura Sismo-resistente, que posibilite la solución integral del problema sísmico de los edificios. Se establecieron los fundamentos, objetivos, principios básicos y metodología para deducir las pautas de compatibilización del diseño arquitectónico con el diseño estructural sismo-resistente. En el presente informe se propone una respuesta arquitectónica desde la morfología, que permite llegar a una forma final ajustada, en el sentido de eliminar toda incompatibilidad respecto de las exigencias o condicionantes sísmicos. Es decir, un proyecto arquitectónico que por su propia morfología satisfaga dichos condicionantes. Una "Forma Final Ajustada" que evita, por sí misma, las engorrosas pautas de compatibilización del diseño estructural con el diseño arquitectónico, transformándolas en respuestas morfológicas a cada condicionante sísmico.

  1. Sphagnum growth in floating cultures: Effect of planting design

    Directory of Open Access Journals (Sweden)

    Y. Hoshi

    2017-11-01

    Full Text Available To establish rapid and stable Sphagnum growth, capitulum culture of a selected strain of S. palustre was carried out using a floating culture method. Four planting treatments were tested at mountain and urban sites in Kumamoto Prefecture on Kyushu Island, south-west Japan. Capitula were planted in colonies of different sizes on 30 cm square floating rafts, but with strict control of the number (75–77 of capitula per raft. The initial cover of live green Sphagnum ranged from 15 to 20 %. Growth of the colonies was followed throughout the growing season (April to November of 2008. After three months, green coverage rates reached 40–50 % in all planting treatments. At the end of the growing season, the highest Sphagnum cover (almost 90 % at the urban site was recorded in the planting treatment with eleven re-introduced colonies of seven capitula (‘11×7cap’, while the highest capitulum number and biomass (dry weight gain occurred in the ‘4×19cap’ planting treatment. Average stem elongation ranged from 5 cm to 7 cm in the ‘77×1cap’ and ‘4×19cap’planting treatments, respectively, indicating that the larger sized colony grew longer stems. However, contrary to expectation, the ‘4×19cap’planting treatment - which had the largest colony size - did not deliver the highest number of newly formed side shoots.

  2. Cell-wall polysaccharides play an important role in decay resistance of Sphagnum and actively depressed decomposition in vitro

    NARCIS (Netherlands)

    Hajek, T.; Ballance, S.; Limpens, J.; Verhoeven, J.T.A.; Zijlstra, M.J.

    2011-01-01

    Sphagnum-dominated peatlands head the list of ecosystems with the largest known reservoirs of organic carbon (C). The bulk of this C is stored in decomposition-resistant litter of one bryophyte genus: Sphagnum. Understanding how Sphagnum litter chemistry controls C mineralization is essential for

  3. The effect of temperature on growth and competition between Sphagnum species

    NARCIS (Netherlands)

    Breeuwer, A.J.G.; Heijmans, M.M.P.D.; Robroek, B.J.M.; Berendse, F.

    2008-01-01

    Peat bogs play a large role in the global sequestration of C, and are often dominated by different Sphagnum species. Therefore, it is crucial to understand how Sphagnum vegetation in peat bogs will respond to global warming. We performed a greenhouse experiment to study the effect of four

  4. Photosynthetic performance in Sphagnum transplanted along a latitudinal nitrogen deposition gradient

    NARCIS (Netherlands)

    Granath, G.; Strengbom, J.; Breeuwer, A.J.G.; Heijmans, M.M.P.D.; Berendse, F.; Rydin, H.

    2009-01-01

    Increased N deposition in Europe has affected mire ecosystems. However, knowledge on the physiological responses is poor. We measured photosynthetic responses to increasing N deposition in two peatmoss species (Sphagnum balticum and Sphagnum fuscum) from a 3-year, north-south transplant experiment

  5. Sphagnum re-introduction in degraded peatlands: the effects of aggregation, species and water table

    NARCIS (Netherlands)

    Robroek, B.J.M.; Ruijven, van J.; Schouten, M.G.C.; Breeuwer, A.J.G.; Crushell, P.H.; Berendse, F.; Limpens, J.

    2009-01-01

    In European peatlands which have been drained and cut-over in the past, re-vegetation often stagnates after the return of a species-poor Sphagnum community. Re-introduction of currently absent species may be a useful tool to restore a typical, and more diverse, Sphagnum vegetation and may ultimately

  6. Sphagnum mosses limit total carbon consumption during fire in Alaskan black spruce forests

    Science.gov (United States)

    G. Shetler; .R. Turetsky; E. Kane; E. Kasischke

    2008-01-01

    The high water retention of hummock-forming Sphagnum species minimizes soil moisture fluctuations and might protect forest floor organic matter from burning during wildfire. We hypothesized that Sphagnum cover reduces overall forest floor organic matter consumption during wildfire compared with other ground-layer vegetation. We...

  7. Greenhouse gas balance of an establishing Sphagnum culture on a former bog grassland in Germany

    Directory of Open Access Journals (Sweden)

    A. Günther

    2017-04-01

    Full Text Available The cultivation of Sphagnum mosses on re-wetted peat bogs for use in horticulture is a new land use strategy. We provide the first greenhouse gas balances for a field-scale Sphagnum farming experiment on former bog grassland, in its establishment phase. Over two years we used closed chambers to make measurements of GHG exchange on production strips of Sphagnum palustre L. and Sphagnum papillosum Lindb. and on irrigation ditches. Methane fluxes of both Sphagnum species showed a significant decrease over the study period. This trend was stronger for S. papillosum. In contrast, the estimated CO2 fluxes did not show a significant temporal trend over the study period. The production strips of both Sphagnum species were net GHG sinks of 5–9 t ha 1 a 1 (in CO2-equivalents during the establishment phase of the moss carpets. In comparison, the ditches were a CO2 source instead of a CO2 sink and emitted larger amounts of CH4, resulting in net GHG release of ~11 t ha 1 a 1 CO2-equivalents. We conclude that Sphagnum farming fields should be designed to minimise the area covered by irrigation ditches. Overall, Sphagnum farming on bogs has lower on-field GHG emissions than low-intensity agriculture.

  8. Biophysical drivers of seasonal variability in Sphagnum gross primary production in a northern temperate bog

    Science.gov (United States)

    Anthony P. Walker; Kelsey R. Carter; Lianhong Gu; Paul J. Hanson; Avni Malhotra; Richard J. Norby; Stephen D. Sebestyen; Stan D. Wullschleger; David J. Weston

    2017-01-01

    Sphagnum mosses are the keystone species of peatland ecosystems. With rapid rates of climate change occurring in high latitudes, vast reservoirs of carbon accumulated over millennia in peatland ecosystems are potentially vulnerable to rising temperature and changing precipitation. We investigate the seasonal drivers of Sphagnum...

  9. Mixing ratio and species affect the use of substrate-derived CO2 by Sphagnum

    NARCIS (Netherlands)

    Limpens, J.; Robroek, B.J.M.; Heijmans, M.M.P.D.; Tomassen, H.B.M.

    2008-01-01

    Question: Can mixing ratio and species affect the use of substrate-derived CO2 by Sphagnum? Location: Poor fen in south Sweden and greenhouse in Wageningen, The Netherlands. Methods: Two mixing ratios of Sphagnum cuspidatum and S. magellanicum were exposed to two levels of CO2 by pumping CO2

  10. Peatland restoration in Canada by the sphagnum moss layer transfer method

    Energy Technology Data Exchange (ETDEWEB)

    Rochefort, L.; Boismenu, C. [Laval Univ., Quebec City, PQ (Canada). Dept. de Phytologie, Peatland Ecology and Research Group; Quinty, F. [SNC-Lavalin, Montreal, PQ (Canada)

    2009-04-01

    This article described a peatland restoration approach that has received international recognition for restoring the ecological functions of cutover sphagnum dominated peatlands. The Peatland Ecology Research Group (PERG) conducted a long-term study at the Bois-des-Bel (BDB) peatland site in Quebec to restore plant composition to a peat accumulating ecosystem. The sphagnum moss layer transfer restoration method includes 5 obligatory steps and one optional. These include planning; surface preparation; plant collection and spreading; straw mulch spreading; blocking drainage ditches; and fertilization if needed. Variable moisture conditions throughout the restoration site contribute to the spatial variability in the development of the sphagnum layer. The site has been monitored each year since its restoration. sphagnum cover reached 60 per cent in the restored zone in 2005, a value close to the range of sphagnum cover found in natural sites. In addition, a new moss layer has developed with an average of 25 cm in thickness. 27 refs., 4 figs.

  11. Effects of bryophytes on succession from alkaline marsh to Sphagnum bog

    Energy Technology Data Exchange (ETDEWEB)

    Glime, J.M.; Wetzel, R.G.; Kennedy, B.J.

    1982-10-01

    The alkaline eastern marsh of Lawrence Lake, a marl lake in southwestern Michigan, was sampled by randomly placed line transects to determine the bryophyte cover and corresponding vascular plant zones. Cluster analysis indicated three distinct bryophyte zones which correspond with the recognized vascular plant zones. Mosses occupied over 50% of the surface in some areas. Invasion of Sphagnum, vertical zonation of the mosses on hummocks, zonation with distance from the lake, the abundance of non-Sphagnum moss hummocks, and the ability of the non-Sphagnum species to lower the pH of marsh water during laboratory incubations are evidence that non-Sphagnum mosses facilitate succession from alkaline marsh to Sphagnum bog.

  12. Ocorrência de fungos filamentosos termo-resistentes em polpa de tomate envasada assepticamente

    Directory of Open Access Journals (Sweden)

    BAGLIONI Flávio

    1999-01-01

    Full Text Available Este trabalho teve como objetivo principal determinar a ocorrência de fungos filamentosos termo-resistentes durante o processamento asséptico de polpa de tomate (8° BRIX. Durante o período de safra de tomate foram feitas amostragens em 9 lotes (3 no início, 3 no pico e 3 em fim de safra e no período de entresafra em 5 lotes. Foi feita a enumeração de fungos termo-resistentes nas amostras coletadas durante as diferentes etapas do processo asséptico de cada lote. Foram obtidas contagens médias relativamente baixas, variando entre <1 e 8UFC/100mL de amostra. As maiores contagens foram obtidas na matéria prima e na água de pré lavagem e transporte. Cinqüenta linhagens de fungos termo-resistentes detectadas no procedimento de enumeração foram isoladas, codificadas e estocadas. Os esporos de cada isolado com 1 mês de cultivo foram submetidos a diferentes choques térmicos para selecionar a linhagem de fungo mais termo-resistente. O isolado de fungo mais termo-resistente (sobrevivência ao choque à 100° C/25 minutos foi identificado como Neosartorya fischeri.

  13. Investigations of the structure and function of bacterial communities associated with Sphagnum mosses.

    Science.gov (United States)

    Opelt, Katja; Chobot, Vladimir; Hadacek, Franz; Schönmann, Susan; Eberl, Leo; Berg, Gabriele

    2007-11-01

    High acidity, low temperature and extremely low concentration of nutrients form Sphagnum bogs into extreme habitats for organisms. Little is known about the bacteria associated with living Sphagnum plantlets, especially about their function for the host. Therefore, we analysed the endo- and ectophytic bacterial populations associated with two widely distributed Sphagnum species, Sphagnum magellanicum and Sphagnum fallax, by a multiphasic approach. The screening of 1222 isolates for antagonistic activity resulted in 326 active isolates. The bacterial communities harboured a high proportion of antifungal (26%) but a low proportion of antibacterial isolates (0.4%). Members of the genus Burkholderia (38%) were found to be the most dominant group of antagonistic bacteria. The finding that a large proportion (89%) of the antagonistic bacteria produced antifungal compounds may provide an explanation for the well-known antimicrobial activity of certain Sphagnum species. The secondary metabolites of the Sphagnum species themselves were analysed by HPLC-PDA. The different spectra of detected compounds may not only explain the antifungal activity but also the species specificity of the microbial communities. The latter was analysed using cultivation-independent single-stranded conformation polymorphism (SSCP) analysis. Using Burkholderia-specific primers we found a high diversity of Burkholderia isolates in the endophytic and ectophytic habitats of Sphagnum. Furthermore, a high diversity of nitrogen-fixing bacteria was detected by using nifH-specific primers, especially inside Sphagnum mosses. In conclusion, this study provides evidence that both Sphagnum species were colonized by characteristic bacterial populations, which appear to be important for pathogen defence and nitrogen fixation.

  14. Outstanding accumulation of Sphagnum palustre in central-southern Italy

    Science.gov (United States)

    Casella, Laura; Zaccone, Claudio

    2017-04-01

    Lake Fibreno is a site where some outstanding anomalies for the flora and vegetation of the wetlands of peninsular Italy are concentrated. Here one the southernmost European population of Sphagnum palustre occurs, and is restricted on the surface of a free-floating island, i.e., a round-shaped portion of fen (with a core of Sphagnum), erratically floating on the surface of a submerged sinkhole. Geological evidences point out the existence in the area of a large lacustrine basin since Late Pleistocene. The progressive filling of the lake, caused by changing in climatic conditions and neotectonic events, resulted in the formation of peat deposits in the area, following different depositional cycles in a swampy environment. So that, the studied free-floating island, probably originated around lake margins in the waterlogged area, was somehow isolated from the bank and started to float. Once the separation occurred, sedge peat stopped to accumulate, thus enhancing the role of S. palustre as the main peat-forming plant. The vegetation occurring at the moment of the isolation of the island was a coverage of Salix cinerea/Populus tremula stands below which cushions of moss and, in a lower extent, Thelypteris palustris/Equisetum palustre accumulated resulting in the formation of 2-3 meters of peat dominated by reeds and sedges. This vegetation has been partially degraded by grazing until 1970s, while in 1980s the lake became a nature reserve. Since then, the succession could resume in a spontaneous and natural way and it was possible for the vegetation to recover to natural dynamics and growing rate. The Sphagnum tussocks were measured in an empirical way at a distance of about 60 years after the last signaling and the result was a measurement of an accretion open to about 70 cm thick. Moreover, in a recent study, a 4-m deep peat core was collected from the centre of the island and results were surprising. In fact, 14C age dating, confirmed using 210Pb and 137Cs, showed

  15. Characteristics of Eastern Canadian cultivated Sphagnum and potential use as a substitute for perlite and vermiculite in peat-based horticultural substrates

    OpenAIRE

    M. Aubé; M. Quenum; L.L. Ranasinghe

    2015-01-01

    Sphagnum cultivation on harvested peatlands to meet wetland restoration objectives could be an economically feasible activity since cultivated Sphagnum has potential horticultural applications. We compared the characteristics of cultivated Sphagnum from Shippagan (Canada) with those of non-cultivated Sphagnum products from Chile, New Zealand and Canada, and assessed its potential as a perlite and vermiculite substitute in horticultural peat-based substrates. Shippagan cultivated Sphagnum was ...

  16. Cassava, yam, sweet potato and ñampi starch: functional properties and possible applications in the food industry. Harinas y almidones de yuca, ñame, camote y ñampí: propiedades funcionales y posibles aplicaciones en la industria alimentaria.

    Directory of Open Access Journals (Sweden)

    Pedro Vargas Aguilar

    2013-03-01

    Full Text Available A technical review was conducted to related physical and chemical properties of flours and starches from cassava, yams, taro and sweet potato. Amyloseamylopectin content, viscosity, nutritional value and fiber, were studied to relate them with starch functional properties. A relationship was obtained between amylose-amylopectin, viscosity and fiber content with the digestibility of those starches and the glycemic index values. The use of fermentation to enhance the nutritional value of these starches is known. Starch fermentation allows the production of gluten-free bread and energy drinks as an option to diversify products. It was also observed the relationship between the starch viscosity and the fat absorption in fried foods.Se realizó una revisión de las características fisicoquímicas de las harinas y almidones de yuca, ñame, ñampí y camote, tales como el contenido de amilosa-amilopectina, la viscosidad, el valor nutricional y la fibra, con el fin de relacionarlas con sus propiedades funcionales y técnico-funcionales. Se obtuvo una relación entre el contenido de amilosa-amilopectina, viscosidad y contenido de fibra en la digestibilidad de estos almidones y los valores de índice glicémico. Se encontró que es posible introducir modificaciones por medio de la fermentación para mejorar el valor funcional de estos almidones. La fermentación permite elaborar pan sin gluten y bebidas energéticas como nuevas opciones de productos. También se encontró que existe una relación entre la viscosidad de los almidones y la disminución de absorción de la grasa en frituras.

  17. Spatio-temporal trends of nitrogen deposition and climate effects on Sphagnum productivity in European peatlands

    International Nuclear Information System (INIS)

    Granath, Gustaf; Limpens, Juul; Posch, Maximilian; Mücher, Sander; Vries, Wim de

    2014-01-01

    To quantify potential nitrogen (N) deposition impacts on peatland carbon (C) uptake, we explored temporal and spatial trends in N deposition and climate impacts on the production of the key peat forming functional group (Sphagnum mosses) across European peatlands for the period 1900–2050. Using a modelling approach we estimated that between 1900 and 1950 N deposition impacts remained limited irrespective of geographical position. Between 1950 and 2000 N deposition depressed production between 0 and 25% relative to 1900, particularly in temperate regions. Future scenarios indicate this trend will continue and become more pronounced with climate warming. At the European scale, the consequences for Sphagnum net C-uptake remained small relative to 1900 due to the low peatland cover in high-N areas. The predicted impacts of likely changes in N deposition on Sphagnum productivity appeared to be less than those of climate. Nevertheless, current critical loads for peatlands are likely to hold under a future climate. - Highlights: • We model the effect of N deposition combined with climate on production of Sphagnum between 1900 and 2050. • Spatially explicit projections are indicated on an updated European peatland distribution map. • Results stress the vulnerability of temperate Sphagnum peatlands to current and future N deposition. • Future impacts of N deposition on Sphagnum productivity likely depend more on climate change than on N deposition rate. - Temperate Sphagnum peatlands are vulnerable to current and future N deposition and current critical loads for peatlands are likely to hold under a future climate

  18. Sphagnum mosses harbour highly specific bacterial diversity during their whole lifecycle.

    Science.gov (United States)

    Bragina, Anastasia; Berg, Christian; Cardinale, Massimiliano; Shcherbakov, Andrey; Chebotar, Vladimir; Berg, Gabriele

    2012-04-01

    Knowledge about Sphagnum-associated microbial communities, their structure and their origin is important to understand and maintain climate-relevant Sphagnum-dominated bog ecosystems. We studied bacterial communities of two cosmopolitan Sphagnum species, which are well adapted to different abiotic parameters (Sphagnum magellanicum, which are strongly acidic and ombrotrophic, and Sphagnum fallax, which are weakly acidic and mesotrophic), in three Alpine bogs in Austria by a multifaceted approach. Great differences between bacterial fingerprints of both Sphagna were found independently from the site. This remarkable specificity was confirmed by a cloning and a deep sequencing approach. Besides the common Alphaproteobacteria, we found a discriminative spectrum of bacteria; although Gammaproteobacteria dominated S. magellanicum, S. fallax was mainly colonised by Verrucomicrobia and Planctomycetes. Using this information for fluorescent in situ hybridisation analyses, corresponding colonisation patterns for Alphaproteobacteria and Planctomycetes were detected. Bacterial colonies were found in high abundances inside the dead big hyalocytes, but they were always connected with the living chlorocytes. Using multivariate statistical analysis, the abiotic factors nutrient richness and pH were identified to modulate the composition of Sphagnum-specific bacterial communities. Interestingly, we found that the immense bacterial diversity was transferred via the sporophyte to the gametophyte, which can explain the high specificity of Sphagnum-associated bacteria over long distances. In contrast to higher plants, which acquire their bacteria mainly from the environment, mosses as the phylogenetically oldest land plants maintain their bacterial diversity within the whole lifecycle.

  19. A phylogenetic delimitation of the "Sphagnum subsecundum complex" (Sphagnaceae, Bryophyta).

    Science.gov (United States)

    Shaw, A Jonathan; Boles, Sandra; Shaw, Blanka

    2008-06-01

    A seemingly obvious but sometimes overlooked premise of any evolutionary analysis is delineating the group of taxa under study. This is especially problematic in some bryophyte groups because of morphological simplicity and convergence. This research applies information from nucleotide sequences for eight plastid and nuclear loci to delineate a group of northern hemisphere peat moss species, the so-called Sphagnum subsecundum complex, which includes species known to be gametophytically haploid or diploid (i.e., sporophytically diploid-tetraploid). Despite the fact that S. subsecundum and several species in the complex have been attributed disjunct ranges that include all major continents, phylogenetic analyses suggest that the group is actually restricted to Europe and eastern North America. Plants from western North America, from California to Alaska, which are morphologically similar to species of the S. subsecundum complex in eastern N. America and Europe, actually belong to a different deep clade within Sphagnum section Subsecunda. One species often considered part of the S. subsecundum complex, S. contortum, likely has a reticulate history involving species in the two deepest clades within section Subsecunda. Nucleotide sequences have a strong geographic structure across the section Subsecunda, but shallow tip clades suggest repeated long-distance dispersal in the section as well.

  20. Symbiosis revisited: phosphorus and acid buffering stimulate N2 fixation but not Sphagnum growth

    Science.gov (United States)

    van den Elzen, Eva; Kox, Martine A. R.; Harpenslager, Sarah F.; Hensgens, Geert; Fritz, Christian; Jetten, Mike S. M.; Ettwig, Katharina F.; Lamers, Leon P. M.

    2017-03-01

    In pristine Sphagnum-dominated peatlands, (di)nitrogen (N2) fixing (diazotrophic) microbial communities associated with Sphagnum mosses contribute substantially to the total nitrogen input, increasing carbon sequestration. The rates of symbiotic nitrogen fixation reported for Sphagnum peatlands, are, however, highly variable, and experimental work on regulating factors that can mechanistically explain this variation is largely lacking. For two common fen species (Sphagnum palustre and S. squarrosum) from a high nitrogen deposition area (25 kg N ha-1 yr-1), we found that diazotrophic activity (as measured by 15 - 15N2 labeling) was still present at a rate of 40 nmol N gDW-1 h-1. This was surprising, given that nitrogen fixation is a costly process. We tested the effects of phosphorus availability and buffering capacity by bicarbonate-rich water, mimicking a field situation in fens with stronger groundwater or surface water influence, as potential regulators of nitrogen fixation rates and Sphagnum performance. We expected that the addition of phosphorus, being a limiting nutrient, would stimulate both diazotrophic activity and Sphagnum growth. We indeed found that nitrogen fixation rates were doubled. Plant performance, in contrast, did not increase. Raised bicarbonate levels also enhanced nitrogen fixation, but had a strong negative impact on Sphagnum performance. These results explain the higher nitrogen fixation rates reported for minerotrophic and more nutrient-rich peatlands. In addition, nitrogen fixation was found to strongly depend on light, with rates 10 times higher in light conditions suggesting high reliance on phototrophic organisms for carbon. The contrasting effects of phosphorus and bicarbonate on Sphagnum spp. and their diazotrophic communities reveal strong differences in the optimal niche for both partners with respect to conditions and resources. This suggests a trade-off for the symbiosis of nitrogen fixing microorganisms with their Sphagnum

  1. Effect of mechanical fragmentation of sphagnum on population density and structure of micromycete communities

    Science.gov (United States)

    Semenova, T. A.; Golovchenko, A. V.

    2017-07-01

    The population density and taxonomic structure of micromycetes were monitored for six months in a model experiment with natural and mechanically fragmented (fine and coarse) samples of sphagnum. Sphagnum fragmentation favored an increase in the number of micromycetes only during the first week of the experiment. On the average, the number of micromycetes in fine-fragmented samples was two times greater than that in the coarse-fragmented samples. The diversity of micromycetes increased in the fragmented samples of sphagnum owing to the activation of some species, which remained in the inactive state as spores in the peat before fragmentation.

  2. Reintroduction of Sphagnum into harvested peatlands: evaluation of various methods for protection against dessication

    Energy Technology Data Exchange (ETDEWEB)

    Rochefort, L.; Bastien, D.F. [Laval University, Sainte-Foy, PQ (Canada). Dept. of Phytology

    1998-09-01

    In order to restore peatlands after peat harvesting operations, Sphagnum diaspores were introduced in combination with 1) physical protection devices or 2) an irrigating system. The response of five Sphagnum species was investigated in relation to two types of peat substrates for two growing seasons. The physical protections consisting of plastic shade cloth (40% and 60% shade) improved the development of a greater number of capitula compared with control surfaces without protection or surfaces covered with a perforated polyethylene sheet. This stimulating effect could be caused by higher humidity created by a shale screen. Irrigation also enhanced the establishment success of Sphagnum but the effect was less successful than expected.

  3. Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe

    Energy Technology Data Exchange (ETDEWEB)

    Jirousek, Martin, E-mail: machozrut@mail.muni.c [Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno (Czech Republic); Hajek, Michal [Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno (Czech Republic); Bragazza, Luca [WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Site Lausanne, Station 2, Case Postale 96, CH-1015 Lausanne (Switzerland); Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory of Ecological Systems - ECOS, Batiment GR, Station 2, CH-1015 Lausanne (Switzerland); Department of Biology and Evolution, University of Ferrara, Corso Ercole I d' Este 32, I-44100 Ferrara (Italy)

    2011-02-15

    We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m{sup -2} year{sup -1} in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient. - Research highlights: Despite high atmopsheric nitrogen deposition, Sphagnum mosses still have rather low N:P ratio. Regional climate and landscape management can enhance P and K availability in bogs. Sphagnum species of the Cuspidata section were characterised by lower N:P ratio. - Regional climate and local forestry practices are expected to alter nutrient stoichiometry in Sphagnum mosses at high atmospheric N deposition in Central-East Europe.

  4. Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe

    International Nuclear Information System (INIS)

    Jirousek, Martin; Hajek, Michal; Bragazza, Luca

    2011-01-01

    We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m -2 year -1 in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient. - Research highlights: → Despite high atmopsheric nitrogen deposition, Sphagnum mosses still have rather low N:P ratio.→ Regional climate and landscape management can enhance P and K availability in bogs. → Sphagnum species of the Cuspidata section were characterised by lower N:P ratio. - Regional climate and local forestry practices are expected to alter nutrient stoichiometry in Sphagnum mosses at high atmospheric N deposition in Central-East Europe.

  5. Effect of repeated mowing to reduce graminoid plant cover on the moss carpet at a Sphagnum farm in North America

    Directory of Open Access Journals (Sweden)

    M. Guêné-Nanchen

    2017-09-01

    Full Text Available Sphagnum farming is defined as the sustainable production of non-decomposed Sphagnum biomass on a cyclical and renewable basis. In this article, the influence and necessity of mowing graminoid plants to optimise Sphagnum growth in Sphagnum farming basins are examined. Repeated mowing was applied to reduce graminoid plant cover at two different stages of the production cycle (one-year-old and seven-year-old Sphagnum moss carpet at the beginning of the experiment at an experimental Sphagnum farm in eastern Canada. Sphagnum growth (cover, biomass, moss layer thickness was measured after three years of mowing. In addition, a greenhouse experiment was carried out to determine whether there is a threshold for graminoid plant cover beyond which mowing becomes necessary. Sphagnum cover and biomass were not affected by repeated mowing, even if mowing reduced the cover of graminoid plants. Thus, it appears that mowing is unnecessary if the dominant vascular species is a graminoid plant such as Eriophorum angustifolium, which accumulates minimal amounts of litter. Furthermore, high cover of Eriophorum angustifolium (up to 85 % did not affect Sphagnum cover in a density-controlled greenhouse experiment. When the specific goal is Sphagnum fibre production, decisions about control of graminoid plants should be made after considering the cover, life form and litter accumulation potentials of the dominant graminoid species involved.

  6. Seasonal pattern of metal bioaccumulation and their toxicity on Sphagnum squarrosum.

    Science.gov (United States)

    Saxena, Anuj

    2006-01-01

    Present study was undertaken as an attempt to study the effect of pollutants on biological responses of Sphagnum growing at Kainchi, Kumaon hills (Uttranchal). Sphagnum plants of almost identical size, collected from the marked sites of Kainchi in different seasons viz., monsoon, winter, summer and again in monsoon, were analysed for chlorophyll, protein, shoot length and nitrate reductase and peroxidase activities. Maximum chlorophyll, protein, shoots length and nitrate reductase activities were observed during the monsoon while minimum in summers. The abundance of Sphagnum and two other bryophytes, Marchantia and Plagiochasma was also higher in monsoon than in other seasons. The study also indicated that Sphagnum has more bioaccumulation and tolerance potential for heavy metals than Marchantia and Plagiochasma.

  7. Response of Sphagnum fuscum to Nitrogen Deposition: A Case Study of Ombrogenous Peatlands in Alberta, Canada

    Science.gov (United States)

    Vitt, D.H.; Wieder, K.; Halsey, L.A.; Turetsky, M.

    2003-01-01

    Peatlands cover about 30% of northeastern Alberta and are ecosystems that are sensitive to nitrogen deposition. In polluted areas of the UK, high atmospheric N deposition (as a component of acid deposition) has been considered among the causes of Sphagnum decline in bogs (ombrogenous peatlands). In relatively unpolluted areas of western Canada and northern Sweden, short-term experimental studies have shown that Sphagnum responds quickly to nutrient loading, with uptake and retention of nitrogen and increased production. Here we examine the response of Sphagnum fuscum to enhanced nitrogen deposition generated during 34 years of oil sands mining through the determination of net primary production (NPP) and nitrogen concentrations in the upper peat column. We chose six continental bogs receiving differing atmospheric nitrogen loads (modeled using a CALPUFF 2D dispersion model). Sphagnum fuscum net primary production (NPP) at the high deposition site (Steepbank - mean of 600 g/m2; median of 486 g/m2) was over three times as high than at five other sites with lower N deposition. Additionally, production of S. fuscum may be influenced to some extent by distance of the moss surface from the water table. Across all sites, peat nitrogen concentrations are highest at the surface, decreasing in the top 3 cm with no significant change with increasing depth. We conclude that elevated N deposition at the Steepbank site has enhanced Sphagnum production. Increased N concentrations are evident only in the top 1-cm of the peat profile. Thus, 34 years after mine startup, increased N-deposition has increased net primary production of Sphagnum fuscum without causing elevated levels of nitrogen in the organic matter profile. A response to N-stress for Sphagnum fuscum is proposed at 14-34 kg ha-1 yr-1. A review of N-deposition values reveals a critical N-deposition value of between 14.8 and 15.7 kg ha -1 yr-1 for NPP of Sphagnum species.

  8. Interferences between Sphagnum and vascular plants: effects on plant community structure and peat formation

    OpenAIRE

    Malmer, Nils; Albinsson, C; Svensson, B M; Wallén, Bo

    2003-01-01

    The interference between vascular plants and peat mosses with respect to nitrogen and phosphorus was studied in a fertilization experiment and with respect to competition for light in a removal experiment in poor fens with either soligenous or topogenous hydrology using Narthecium ossifragum (L.) Huds. and three species of Sphagnum sect. Sphagnum as targets. Adding fertilizer either on the moss surface or below it confirmed the hypotheses of an asymmetric competition for nutrients, viz. that ...

  9. Factors controlling sulfur gas exchange in Sphagnum-dominated wetlands

    Science.gov (United States)

    Demello, William Zamboni; Hines, Mark E.; Bayley, Suzanne E.

    1992-01-01

    Atmosphere-peatland exchange of reduced sulfur gases was determined seasonally in fen in NH, and in an artificially-acidified fen at the Experimental Lakes Area (ELA) in Canada. Dimethyl sulfide (DMS) dominated gas fluxes at rates as high as 400 nmol/m(sup -2)hr(sup -1). DMS fluxes measured using enclosures were much higher than those calculated using a stagnant-film model, suggesting that Sphagnum regulated efflux. Temperature controlled diel and seasonal variability in DMS emissions. Use of differing enclosure techniques indicated that vegetated peatlands consume atmospheric carbonyl sulfide. Sulfate amendments caused DMS and methane thiol concentrations in near-surface pore waters to increase rapidly, but fluxes of these gases to the atmosphere were not affected. However, emission data from sites experiencing large differences in rates of sulfate deposition from the atmosphere suggested that chronic elevated sulfate inputs enhance DMS emissions from northern wetlands.

  10. Ecophysiological adjustment of two Sphagnum species in response to anthropogenic nitrogen deposition.

    Science.gov (United States)

    Wiedermann, Magdalena M; Gunnarsson, Urban; Ericson, Lars; Nordin, Annika

    2009-01-01

    Here, it was investigated whether Sphagnum species have adjusted their nitrogen (N) uptake in response to the anthropogenic N deposition that has drastically altered N-limited ecosystems, including peatlands, worldwide. A lawn species, Sphagnum balticum, and a hummock species, Sphagnum fuscum, were collected from three peatlands along a gradient of N deposition (2, 8 and 12 kg N ha(-1) yr(-1)). The mosses were subjected to solutions containing a mixture of four N forms. In each solution one of these N forms was labeled with (15)N (namely (15)NH(+)(4), (15)NO(-)(3) and the amino acids [(15)N]alanine (Ala) and [(15)N]glutamic acid (Glu)). It was found that for both species most of the N taken up was from , followed by Ala, Glu, and very small amounts from NO(-)(3). At the highest N deposition site N uptake was reduced, but this did not prevent N accumulation as free amino acids in the Sphagnum tissues. The reduced N uptake may have been genetically selected for under the relatively short period with elevated N exposure from anthropogenic sources, or may have been the result of plasticity in the Sphagnum physiological response. The negligible Sphagnum NO(-)(3) uptake may make any NO(-)(3) deposited readily available to co-occurring vascular plants.

  11. Cell-wall polysaccharides play an important role in decay resistance of Sphagnum and actively depressed decomposition in vitro

    OpenAIRE

    Hajek, T.; Ballance, S.; Limpens, J.; Verhoeven, J.T.A.; Zijlstra, M.J.

    2011-01-01

    Sphagnum-dominated peatlands head the list of ecosystems with the largest known reservoirs of organic carbon (C). The bulk of this C is stored in decomposition-resistant litter of one bryophyte genus: Sphagnum. Understanding how Sphagnum litter chemistry controls C mineralization is essential for understanding potential interactions between environmental changes and C mineralization in peatlands. We aimed to separate the effects of phenolics from structural polysaccharides on decay of Sphagnu...

  12. Sphagnum restoration on degraded blanket and raised bogs in the UK using micropropagated source material: a review of progress

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    S.J.M Caporn

    2018-05-01

    Full Text Available There is a growing demand for a supply of Sphagnum to re-introduce to degraded peatlands. However, available supplies of Sphagnum of the desired species are often limited. We describe the propagation of Sphagnum from vegetative material in sterile tissue culture and the introduction of juvenile mosses into the field. Sphagnum produced in the laboratory in three different forms (beads, gel and plugs was introduced to different peatland surfaces on upland degraded blanket bog and lowland cut-over peatland in northern England. On degraded blanket bog, the establishment of mixed-species Sphagnum plugs was typically 99 % while the survival of beads was much lower, ranging from little above zero on bare eroding peat to a maximum of 12 % on stabilised peat surfaces. On lowland cut-over peatland, all trials took place on peat with an expanding cover of Eriophorum angustifolium and tested Sphagnum gel as well as beads and plugs. This work showed that survival and establishment of plugs was high (99 % and greater than for beads. Sphagnum gel reached a cover of 95 % in two years. The vegetative micropropagation of Sphagnum offers an effective source of Sphagnum for re-introduction to degraded peatlands.

  13. Nuevas perspectivas sobre las culturas botánicas precolombinas de Puerto Rico: implicaciones del estudio de almidones en herramientas líticas, cerámicas y de concha

    Directory of Open Access Journals (Sweden)

    Jaime R. Pagán Jiménez

    2009-11-01

    Full Text Available El presente artículo muestra una síntesis de la información arqueobotánica más reciente para Puerto Rico proveniente del estudio de granos de almidón recuperados en artefactos arqueológicos. Dichos artefactos, así como los almidones antiguos presentes en ellos debido a la maceración, a la molienda o a la cocción de órganos vegetales, se ubican cronológicamente en casi todos los períodos culturales precolombinos hasta ahora definidos para la isla. Se discuten brevemente las implicaciones de los resultados arqueobotánicos logrados en torno a tres tópicos altamente generalizados y aceptados en nuestra región, pero actualmente cuestionados: a el carácter de las culturas botánicas de los llamados cazadores-pescadores-recolectores, b la atribuida importancia de la yuca para los pueblos agroceramistas antillanos de origen continental y c la generalizada percepción que se tiene acerca del protagonismo que tuvieron plantas como la yuca y el maíz en el desarrollo de las complejidades culturales tardías de las islas antillanas.

  14. Staphylococcus aureus Meticilina Resistente (MRSA e Infecções Nosocomiais

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    CRISTINA PAIVA SOUSA

    2009-12-01

    Full Text Available Um número crescente de cepas de Staphylococcus aureus meticilina resistente (MRSA apresentam resistência a múltiplos agentes antimicrobianos e são implicadas como causas de infecções hospitalares. S. aureus podem ser isolados de ambiente hospitalar e profissionais da saúde, revelando o risco de transmissão desses microrganismos pelo contato direto ou indireto com pacientes hospitalizados. Objetivou-se nesta revisão correlacionar este microrganismo com infecções hospitalares e avaliar as possíveis fontes de infecção, bem como enfatizar a importância do investimento em ações de educação em saúde que culminem em minimização de infecções hospitalares. Palavras-chave: Staphylococcus aureus meticilina resistente. Infecções nosocomiais.

  15. Three-genome mosses: complex double allopolyploid origins for triploid gametophytes in Sphagnum.

    Science.gov (United States)

    Karlin, Eric F; Boles, S B; Ricca, M; Temsch, E M; Greilhuber, J; Shaw, A J

    2009-04-01

    This paper documents the occurrence of allotriploidy (having three differentiated genomes) in gametophytes of two Southern Hemisphere Sphagnum species (S. australe, S. falcatulum). The pattern of microsatellite alleles indicates that both species are composed of a complex of allodiploid and allotriploid gametophytes, with the latter resulting from two allopolyploidization events. No haploid (n = x) gametophytes were found for either species. The ploidal levels suggested by the pattern of microsatellite alleles were confirmed by flow cytometry and Feulgen DNA image densitometry. For both S. australe and S. falcatulum, the respective allodiploid plants (or their ancestors) are one of the parent species of the allotriploid plants. This is the first report of triploidy in Sphagnum gametophytes occurring in nature and also the first report of the presence of three differentiated genomes in any bryophyte. It is also the first report of intersectional allopolyploidy in Sphagnum, with S. australe appearing to have parental species from Sphagnum sections Rigida and Sphagnum, and S. falcatulum having parental species from Sphagnum sections Cuspidata and Subsecunda. In both species, the allotriploid cytotypes were the most prevalent cytotype on the South Island of New Zealand. The pattern of microsatellite alleles shows the presence of two genetically distinct populations of allodiploid S. australe, possibly indicating multiple origins of polyploidy for that allodiploid cytotype. Morphological evidence is also highly indicative of recurrent polyploidy in the allotriploid cytotype of S. falcatulum. Allopolyploidy has clearly played a major evolutionary role in these two Southern Hemisphere taxa. This study, in conjunction with other recent research, indicates that allopolyploidy is a common, if not the predominant, form of polyploidy in Sphagnum.

  16. Similar diversity of Alphaproteobacteria and nitrogenase gene amplicons on two related Sphagnum mosses

    Directory of Open Access Journals (Sweden)

    Anastasia eBragina

    2012-01-01

    Full Text Available Sphagnum mosses represent a main component in ombrotrophic wetlands. They harbor a specific and diverse microbial community with essential functions for the host. To understand extend and degree of host specificity, Sphagnum fallax and S. angustifolium, two phylogenetically closely related species, which show distinct habitat preference with respect to the nutrient level, were analyzed by a multifaceted approach. Microbial fingerprints obtained by PCR-SSCP (single-strand conformation polymorphism using universal, group-specific and functional primers were highly similar. Similarity was confirmed for colonization patterns obtained by fluorescence in situ hybridization (FISH coupled with confocal laser scanning microscopy (CLSM: Alphaproteobacteria were the main colonizers inside the hyaline cells of Sphagnum leaves. A deeper survey of Alphaproteobacteria by 16S rRNA gene amplicon sequencing reveals a high diversity with Acidocella, Acidisphaera, Rhodopila and Phenylobacterium as major genera for both mosses. Pathogen defense and nitrogen fixation are important functions of Sphagnum-associated bacteria, which are fulfilled by microbial communities of both Sphagna in a similar way. NifH libraries of Sphagnum-associated microbial communities were characterized by high diversity and abundance of Alphaproteobacteria but contained also diverse amplicons of other taxa, e.g. Cyanobacteria, Geobacter and Spirochaeta. Statistically significant differences between the microbial communities of both Sphagnum species could not be discovered in any of the experimental approach. Our results show that the same close relationship, which exists between the physical, morphological and chemical characteristics of Sphagnum mosses and the ecology and function of bog ecosystems, also connects moss plantlets with their associated bacterial communities.

  17. Genotipos de frijol (Phaseolus Vulgaris l. resistentes a Xanthomonas campestris pv. phaseoli de Mexico

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    Rosa Navarrete

    2000-01-01

    Full Text Available Genotipos de frijol (Phaseolus vulgaris L. resistentes a Xanthomonas campestris pv. phaseoli de México. Durante 1995 se evaluó la reacción de genotipos de frijol de diversos origenes a Xcp, bajo condiciones de invernadero en el Campo Experimental del Valle de México, del INIFAP. Se realizaron tres experimentos con a120, b44 y csiete genotipos de frijol. Las plantas se inocularon por corte con navajas en la etapa V3, a y b con una mezcla de nueve cepas de Xcp y el c, con cada una de siete cepas con diferente grado de patogenicidad. La severidad se evaluó 20 días después de la inoculación, por comparación con una escala visual de nueve grados. Los datos se analizaron bajo un diseño completamente al azar. En a, los genotipos que mostraron reacción de resistencia a Xcp fueron: A 36, A 475, G 5686, G 11867, Harowood, SEA 14, XAN 266, MCD 4012 y REN 27. En b los genotipos resistentes fueron: Sequía Durango, Taylor y XAN 30. En los experimentos anteriores la severidad de la enfermedad mostró una distribución normal, con el máximo número de genotipos en el grado de severidad cinco en a y seis en b. Los resultados obtenidos indican que el uso de mezclas de cepas de bacterias con diferente patogenicidad es eficiente para identificar genotipos de frijol resistentes a Xcp. Los genotipos resistentes identificados en el último experimento, mostraron respuesta diferencial e interacciones genotipo por cepa. REN 27 y SEA 14 mostraron resistencia a las cepas utilizadas

  18. Staphylococcus aureus resistente a meticilina asociado a la comunidad: aspectos epidemiológicos y moleculares

    Directory of Open Access Journals (Sweden)

    Daniel Angel Luján Roca

    2013-01-01

    Full Text Available El Staphylococcus aureus resistente a meticilina asociado a la comunidad (SARM-AC está ampliamente diseminado en el mundo. Es epidémico en algunos países y posee dos marcadores moleculares característicos: el SCCmec IV y la leucocidina de Panton-Valentine, ambos escasamente encontrados en el SARM asociado a la asistencia médica.

  19. SOJA IAC/IAS-5: CULTIVAR RESISTENTE AO CANCRO DA HASTE

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    MASCARENHAS HIPÓLITO ASSUNÇÃO ANTONIO

    1998-01-01

    Full Text Available Há aproximadamente oito anos, o cancro da haste (Phomopsis phaseoli f. sp. meridionalis/Diaporthe phaseolorum f. sp. meridionalis da soja tem sido o principal fator limitante da produtividade em áreas de manifestação da doença. O seu controle mediante cultivares resistentes é o método mais econômico. Num ensaio em casa de vegetação, visando avaliar o efeito de doses de potássio no controle do cancro da haste, no cultivar IAS-5, moderadamente resistente, verificou-se haver plantas altamente resistentes, comprovadas em três gerações, todas inoculadas com o fungo causador da doença. A importância da obtenção do IAS-5 e de sua multiplicação deve-se a ser o mais cultivado no Estado de São Paulo e apresentar resistência ao cancro da haste.

  20. Biological N2 fixation mainly controlled by Sphagnum tissue N:P ratio in ombrotrophic bogs

    Science.gov (United States)

    Zivkovic, Tatjana; Moore, Tim R.

    2017-04-01

    Most of the 18 Pg nitrogen (N) accumulated in northern nutrient-poor and Sphagnum-dominated peatlands (bogs and fens) can be attributed to N2-fixation by diazotrophs either associated with the live Sphagnum or non-symbiotically in the deeper peat such as through methane consumption close to the water table. Where atmospheric N deposition is low (Sphagnum, suggested by the increase in tissue N:P to >16. It is unclear how Sphagnum-hosted diazotrophic activity may be affected by N deposition and thus changes in N:P ratio. First, we investigated the effects of long-term addition of different sources of nitrogen (0, 1.6, 3.2 and 6.4 g N m-2 y-1as NH4Cl and NaNO3), and phosphorus (5 g P m-2 y-1as KH2PO4) on Sphagnum nutrient status (N, P and N:P ratio), net primary productivity (NPP) and Sphagnum-associated N2fixation at Mer Bleue, a temperate ombrotrophic bog. We show that N concentration in Sphagnum tissue increased with larger rates of N addition, with a stronger effect on Sphagnum from NH4 than NO3. The addition of P created a 3.5 fold increase in Sphagnum P content compared to controls. Sphagnum NPP decreased linearly with the rise in N:P ratio, while linear growth declined exponentially with increase in Sphagnum N content. Rates of N2-fixation determined in the laboratory significantly decreased in response to even the smallest addition of both N species. In contrast, the addition of P increased N2 fixation by up to 100 times compared to N treatments and up to 5-30 times compared to controls. The change in N2-fixation was best modeled by the N:P ratio, across all experimental treatments. Secondly, to test the role of N:P ratio on N2-fixation across a range of bogs, eight study sites along the latitudinal gradient from temperate, boreal to subarctic zone in eastern Canada were selected. From each bog, two predominant microptopographies, hummocks and hollows, were tested for both N2-fixation activity in the laboratory and Sphagnum tissue concentrations of N, P and N

  1. Tangled history of the European uses of Sphagnum moss and sphagnol.

    Science.gov (United States)

    Drobnik, Jacek; Stebel, Adam

    2017-09-14

    Sphagnum mosses and peat could have been utilized as wound dressings for centuries, however reliable data on this subject are ambiguous; sometimes even no distinction between peat moss (Sphagnum spp.) and peat is made or these terms become confused. The first scientific account on surgical use of peat comes from 1882: a peat digger who successfully, by himself and in the way unknown to the then medicine, cured an open fracture of his forearm with peat. The peat, and very soon the peat moss itself (which is the major constituent of peat) drew attention of the 19th-century surgeons. We search for reliable information on: (1) inspirations for Sphagnum usage for medical purposes and its beginnings in the 19th century, (2) substances or products named sphagnol and their connections with (1); (3) on the origin of this name, (4) and on the occurrence of this name in medical sources. We have identified and studied published sources on the uses of peat-based and Sphagnum-based preparations and products of any processing level (including herbal stock, distillate, isolated pure or impure active principle, or a mixture of such) in surgery, pharmacy or cosmetics. A special attention was paid to the name sphagnol, which appeared many a time, in more than one context since 1899. Source publications were critically analysed from the taxonomical, pharmacognostical and ethnopharmacological points of view. Gathered data were cross-checked with the modern knowledge of the biologically active principles of Sphagnum and the prospects of their medical use. The application of peat in surgery started 1882. The use of peat moss as dressings was developed in the 1880's. It returned to surgical practice during WW1. The name sphagnol has two meanings: (1) A chemical substance isolated from the cell walls of Sphagnum mosses in 1899. A post-1950 research showed it to be a mixture of phenols dominated by sphagnum acid. (2) A product of dry distillation of peat contains solid and liquid fractions

  2. Detection, Isolation, and Characterization of Acidophilic Methanotrophs from Sphagnum Mosses ▿ †

    Science.gov (United States)

    Kip, Nardy; Ouyang, Wenjing; van Winden, Julia; Raghoebarsing, Ashna; van Niftrik, Laura; Pol, Arjan; Pan, Yao; Bodrossy, Levente; van Donselaar, Elly G.; Reichart, Gert-Jan; Jetten, Mike S. M.; Sinninghe Damsté, Jaap S.; Op den Camp, Huub J. M.

    2011-01-01

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphaproteobacterial methanotrophs was found. With Sphagnum mosses as the inoculum, alpha- and gammaproteobacterial acidophilic methanotrophs were isolated using established and newly designed media. The 16S rRNA, pmoA, pxmA, and mmoX gene sequences showed that the alphaproteobacterial isolates belonged to the Methylocystis and Methylosinus genera. The Methylosinus species isolated are the first acid-tolerant members of this genus. Of the acidophilic gammaproteobacterial strains isolated, strain M5 was affiliated with the Methylomonas genus, and the other strain, M200, may represent a novel genus, most closely related to the genera Methylosoma and Methylovulum. So far, no acidophilic or acid-tolerant methanotrophs in the Gammaproteobacteria class are known. All strains showed the typical features of either type I or II methanotrophs and are, to the best of our knowledge, the first isolated (acidophilic or acid-tolerant) methanotrophs from Sphagnum mosses. PMID:21724892

  3. Holocene climate variability revealed by oxygen isotope analysis of Sphagnum cellulose from Walton Moss, northern England

    Science.gov (United States)

    Daley, T. J.; Barber, K. E.; Street-Perrott, F. A.; Loader, N. J.; Marshall, J. D.; Crowley, S. F.; Fisher, E. H.

    2010-07-01

    Stable isotope analyses of Sphagnum alpha-cellulose, precipitation and bog water from three sites across northwestern Europe (Raheenmore, Ireland, Walton Moss, northern England and Dosenmoor, northern Germany) over a total period of 26 months were used to investigate the nature of the climatic signal recorded by Sphagnum moss. The δ18O values of modern alpha-cellulose tracked precipitation more closely than bog water, with a mean isotopic fractionation factor αcellulose-precipitation of 1.0274 ± 0.001 (1 σ) (≈27‰). Sub-samples of isolated Sphagnum alpha-cellulose were subsequently analysed from core WLM22, Walton Moss, northern England yielding a Sphagnum-specific isotope record spanning the last 4300 years. The palaeo-record, calibrated using the modern data, provides evidence for large amplitude variations in the estimated oxygen isotope composition of precipitation during the mid- to late Holocene. Estimates of palaeotemperature change derived from statistical relationships between modern surface air temperatures and δ18O precipitation values for the British Isles give unrealistically large variation in comparison to proxies from other archives. We conclude that use of such relationships to calibrate mid-latitude palaeo-data must be undertaken with caution. The δ18O record from Sphagnum cellulose was highly correlated with a palaeoecologically-derived index of bog surface wetness (BSW), suggesting a common climatic driver.

  4. Interploidal hybridization and mating patterns in the Sphagnum subsecundum complex.

    Science.gov (United States)

    Ricca, M; Szövényi, P; Temsch, E M; Johnson, M G; Shaw, A J

    2011-08-01

    Polyploidization is thought to result in instant sympatric speciation, but several cases of hybrid zones between one of the parental species and its polyploid derivative have been documented. Previous work showed that diploid Sphagnum lescurii is an allopolyploid derived from the haploids S. lescurii (maternal progenitor) and S. subsecundum (paternal progenitor). Here, we report the results from analyses of a population where allodiploid and haploid S. lescurii co-occur and produce sporophytes. We tested (i) whether haploids and diploids form hybrid triploid sporophytes; (ii) how hybrid and nonhybrid sporophytes compare in fitness; (iii) whether hybrid sporophytes form viable spores; (iv) the ploidy of any viable gametophyte offspring from hybrid sporophytes; (v) the relative viability of sporelings derived from hybrid and nonhybrid sporophytes; and (vi) if interploidal hybridization results in introgression between the allopolyploid and its haploid progenitor. We found that triploid hybrid sporophytes do occur and are larger than nonhybrid sporophytes, but exhibit very low germination percentages and produce sporelings that develop more slowly than those from nonhybrid sporophytes. All sporophytes attached to haploid gametophytes were triploid and were sired by diploid males, but all sporophytes attached to diploid gametophytes were tetraploid. This asymmetric pattern of interploidal hybridization is related to an absence of haploid male gametophytes in the population. Surprisingly, all sporelings from triploid sporophytes were triploid, yet were genetically variable, suggesting some form of aberrant meiosis that warrants further study. There was limited (but some) evidence of introgression between allodiploid and haploid S. lescurii. © 2011 Blackwell Publishing Ltd.

  5. Nutrient additions in pristine Patagonian Sphagnum bog vegetation : can phosphorus addition alleviate (the effects of) increased nitrogen loads

    NARCIS (Netherlands)

    Fritz, C.; Dijk, G. van; Smolders, A.J.P.; Pancotto, V.A.; Elzenga, J.T.M.; Roelofs, J.G.M.; Grootjans, A.P.

    Sphagnum-bog ecosystems have a limited capability to retain carbon and nutrients when subjected to increased nitrogen (N) deposition. Although it has been proposed that phosphorus (P) can dilute negative effects of nitrogen by increasing biomass production of Sphagnum mosses, it is still unclear

  6. Methanotrophic activity and diversity in different Sphagnum magellanicum dominated habitats in the southernmost peat bogs of Patagonia

    NARCIS (Netherlands)

    Kip, N.; Fritz, C.; Langelaan, E. S.; Pan, Y.; Bodrossy, L.; Pancotto, V.; Jetten, M. S. M.; Smolders, A. J. P.; den Camp, H. J. M. Op

    2012-01-01

    Sphagnum peatlands are important ecosystems in the methane cycle. Methanotrophs living inside the dead hyaline cells or on the Sphagnum mosses are able to act as a methane filter and thereby reduce methane emissions. We investigated in situ methane concentrations and the corresponding activity and

  7. Regeneration and vegetative propagation of Sphagnum palustre as factor of population stability

    Directory of Open Access Journals (Sweden)

    Dygna Sobotka

    2015-01-01

    Full Text Available The stability of the Sphagnum palustre populations on the meadows of the Kampinos National Park situated north-west of Warsaw was investigated in the period 1971-1974. Laboratory cultures were also started to establish the regenerative ability of various gametophyte parts of Sphagnum: the main stem, branches, leaves and spore germination. The green stems and apical branches of the plants showed the highest regeneration ability. Brown stems and white branches developed less intensively. Leaves showed no tendency to develop into new plants. Gametophores were found to form quicker and more effectively by way of regeneration than from spores. In natural conditions more intensive growth of branchings (new shoots from the apical and green parts of Sphagnum was also observed, whereas the brown parts did not exhibit this ability.

  8. Sphagnum can 'filter' N deposition, but effects on the plant and pore water depend on the N form.

    Science.gov (United States)

    Chiwa, Masaaki; Sheppard, Lucy J; Leith, Ian D; Leeson, Sarah R; Tang, Y Sim; Cape, J Neil

    2016-07-15

    The ability of Sphagnum moss to efficiently intercept atmospheric nitrogen (N) has been assumed to be vulnerable to increased N deposition. However, the proposed critical load (20kgNha(-1)yr(-1)) to exceed the capacity of the Sphagnum N filter has not been confirmed. A long-term (11years) and realistic N manipulation on Whim bog was used to study the N filter function of Sphagnum (Sphagnum capillifolium) in response to increased wet N deposition. On this ombrotrophic peatland where ambient deposition was 8kgNha(-1)yr(-1), an additional 8, 24, and 56kgNha(-1)yr(-1) of either ammonium (NH4(+)) or nitrate (NO3(-)) has been applied for 11years. Nutrient status of Sphagnum and pore water quality from the Sphagnum layer were assessed. The N filter function of Sphagnum was still active up to 32kgNha(-1)yr(-1) even after 11years. N saturation of Sphagnum and subsequent increases in dissolved inorganic N (DIN) concentration in pore water occurred only for 56kgNha(-1)yr(-1) of NH4(+) addition. These results indicate that the Sphagnum N filter is more resilient to wet N deposition than previously inferred. However, functionality will be more compromised when NH4(+) dominates wet deposition for high inputs (56kgNha(-1)yr(-1)). The N filter function in response to NO3(-) uptake increased the concentration of dissolved organic N (DON) and associated organic anions in pore water. NH4(+) uptake increased the concentration of base cations and hydrogen ions in pore water though ion exchange. The resilience of the Sphagnum N filter can explain the reported small magnitude of species change in the Whim bog ecosystem exposed to wet N deposition. However, changes in the leaching substances, arising from the assimilation of NO3(-) and NH4(+), may lead to species change. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Epidemia de tuberculosis multidrogo resistente y extensivamente resistente a drogas (TB MDR/XDR en el Perú: situación y propuestas para su control

    Directory of Open Access Journals (Sweden)

    Hernán Del Castillo

    2009-07-01

    Full Text Available En este artículo se describe el estado actual de las epidemias de tuberculosis multidrogo resitente (TB MDR y tuberculosis extensivamente resistente a drogas (TB XDR en el Perú. Se realiza un análisis de nuestra situación con respecto al resto de Latinoamérica, y de la distribución temporo espacial de los casos de TB XDR en Lima. También presentamos nuestra reflexión de lo que está pasando y debe cambiar; lo que se resume en darle la importancia debida a un problema que nos está rebasando y anteponer a nuestros propios intereses, los intereses de la humanidad; por consiguiente no podemos callar, y debemos declarar a la tuberculosis como emergencia sanitaria nacional. Eso constituye una respuesta, esperamos, aún viable para el Perú.

  10. Carbon balance modification in Sphagnum-dominated peat mesocosms invaded by Molinia caerulea

    Science.gov (United States)

    Leroy, Fabien; Gogo, Sébastien; Guimbaud, Christophe; Bernard-Jannin, Léonard; Laggoun-Défarge, Fatima

    2017-04-01

    Plant communities have a key role in regulating greenhouse gas (GHG) emissions in peatland ecosystems and thus on their capacity to act as carbon (C) sink. However, in response to global change, boreal and temperate peatlands may shift from Sphagnum to vascular plant-dominated peatlands that may alter their C-sink function. We set up a mesocosm experiment to investigate how the main GHG fluxes (CO2 and CH4) are affected by plant community modification from Sphagnum mosses to Molinia caerulea dominance. Gross primary production (GPP), ecosystem respiration (ER) and CH4 emissions models were used to compare the C balance and global warming potential under both vegetation cover. While the annual CO2 and CH4 emissions modeling estimated an output of respectively 652 and 18 gC m-2 y-1 in Sphagnum mesocosms, it represented a release of 1473 and 50 gC m-2 y-1 with Molinia caerulea occurrence. Annual modeled GPP was respectively -495 and -1968 gC m-2 y-1 in Sphagnum and Molinia mesocosms leading to a net ecosystem carbon balance (NECB) of 175 g gC m-2 y-1 in Sphagnum mesocosms (i.e., a C-source) and of -445 gC m-2 y-1 for Molinia ones (i.e., a C-sink). Even if CH4 emission accounted for a small part of the gaseous C efflux ( 3%), its global warming potential value to get CO2 equivalent makes both plant communities acting as a warming climate effect. The vegetation shift from Sphagnum mosses to Molinia caerulea seems beneficial for C sequestration regarding the gaseous pool. However, roots and litters of Molinia caerulea could further provide substrates for C emissions and dissolved organic C release.

  11. Bioaccumulation and glutathione-mediated detoxification of copper and cadmium in Sphagnum squarrosum Crome Samml.

    Science.gov (United States)

    Saxena, Anuj; Saxena, Anjali

    2012-07-01

    Physiological and biochemical responses, metal bioaccumulation and tolerance potential of Sphagnum squarrosum Crome Samml. to Cu and Cd were studied to determine its bioindication and bioremediation potential. Results suggest that glutathione treatment increases the metal accumulation potential and plays a definite role in heavy metal scavenging. High abundance of Sphagnum in metal-rich sites strongly suggests its high metal tolerance capabilities. This experiment demonstrates that S. squarrosum is able to accumulate and tolerate a high amount of metals and feasibility of its application as bioindicator and remediator test species of metal-contaminated environment.

  12. Alternative substrates to the sphagnum moss in the acclimatization of arundina graminifolia “alba”(Orchidaceae)

    OpenAIRE

    Ana Paula Zandoná; Ricardo Tadeu de Faria; Alessandro Borini Lone; Rodrigo Thibes Hoshino

    2014-01-01

    The Arundina graminifolia, is popularly known as bamboo orchid, by having their stems quite extensive. It is widely used in the business landscape, with a very rustic plant. Sphagnum moss is the most widely used substrate in the acclimatization of orchids, but environmental issues have led to an increase in the search for alternative substrates. The objective of this study was to evaluate substrates that can replace all or part of the use of sphagnum moss on the acclimatization of A. graminif...

  13. Water flow in Sphagnum hummocks: Mesocosm measurements and modelling

    Science.gov (United States)

    Price, Jonathan S.; Whittington, Peter N.

    2010-02-01

    SummaryThe internal water fluxes within Sphagnum mosses critically affect the rate of evaporation and the wetness of the living upper few centimetres of moss (capitula) and the physiological processes (e.g. photosynthesis) that support them. To quantify water fluxes and stores in Sphagnum rubellum hummocks we used a 30 cm high column (mesocosm) of undisturbed hummock moss including the capitula, and applied a number of experiments to investigate (1) staged lowering (and raising) of the water table ( wt) with a manometer tube; (2) pumped seepage of about 0.7 cm d -1 to produce a wt drop of 1.5 cm day -1; and (3) evaporation averaging 3.2 mm d -1. Water content ( θ) at saturation ( θ s) was ˜0.9 cm 3 cm -3 for all depths. Residual water content ( θ r) was 0.2 cm 3 cm -3 at 5 cm depth, increasing to 0.47 cm 3 cm -3 at 25 cm depth. Hydraulic conductivity ( K) of the same top 5 cm layer ranged from 1.8 × 10 -3 m s -1 at θ s to 4 × 10 -8 m s -1 at θ r. By comparison K at 25 cm depth had a much more limited range from 2.3 × 10 -4 m s -1 at θ s to 1.1 × 10 -5 m s -1 at θ r. Staged wt lowering from -10 cm to -30 cm (no evaporation allowed) resulted in an abrupt change in θ that reached a stable value generally within an hour, indicating the responsiveness of moss to drainage. Staged increases also resulted in an abrupt rise in θ, but in some cases several days were required for θ to equilibrate. Pumped seepage resulted in a sequential decline of θ, requiring about 10 days for each layer to reach θ r after the water table dropped below the sensor at the respective depths. Evaporation resulted in a similar pattern of decline but took almost three times as long. The computer simulation Hydrus 1D was used to model the fluxes and provided a good fit for the staged lowering and pumped seepage experiments, but overestimated the water loss by evaporation. We believe the reason for this is that over the longer evaporation experiment, the monolith underwent

  14. Ion exchange in sphagnum and its relation to bog ecology

    Energy Technology Data Exchange (ETDEWEB)

    Clymo, R S

    1963-01-01

    In sphagnum cuspidatum unesterified polyuronic acids form 12 percent of the dry weight; in S. acutifolium 25 percent of the dry weight. A good correlation has been found for sphagna between the content of unesterified polyuronic acid and the cation exchange ability, and between cation exchange ability and height of normal habitat above the water table. Anion exchange ability in sphagna is less than 0.0026 m.eq./g. d.w. compared with about 1.2 m.eq./g. d.w. for cations at pH values above 7. In natural conditions the exchange sites are, however, only partly dissociated. The production of new plant material in a bog dependent on rainwater for nurients can be sufficient to maintain the pH below 4.5, but on other than H/sup +/ could be retained in exchangeable form. A greater proportion of polyvalent cations could be retained. The kinetics of cation exchange are consistent with a heterogeneous exchange phase containing regions of high charge density and regions with lower charge density. At equilibrium the proportions of different cations in the exchange phase are largely explicable by a Donnan distribution, but there are notable exceptions. Two estimates based on donnan distribution suggest that with low external pH and/or low cation concentration the apparent concentration of exchange sites may be 2-3 eq./l., falling with rise in pH and/or increase in cation concentration to 0.9 -1.5 eq./l. The apparent dissociation coefficient also varies in these conditions from 2 x 10/sup -3/ to 1 x 10/sup -4/.

  15. Characteristics of Eastern Canadian cultivated Sphagnum and potential use as a substitute for perlite and vermiculite in peat-based horticultural substrates

    Directory of Open Access Journals (Sweden)

    M. Aubé

    2015-03-01

    Full Text Available Sphagnum cultivation on harvested peatlands to meet wetland restoration objectives could be an economically feasible activity since cultivated Sphagnum has potential horticultural applications. We compared the characteristics of cultivated Sphagnum from Shippagan (Canada with those of non-cultivated Sphagnum products from Chile, New Zealand and Canada, and assessed its potential as a perlite and vermiculite substitute in horticultural peat-based substrates. Shippagan cultivated Sphagnum was shorter than the Chilean and New Zealand products with which it was compared, yet more similar to them than to the Canadian product currently on the market. Laboratory tests on physical properties and greenhouse growth trials indicated that 50–100 % of the perlite or vermiculite of a peat-based substrate can be successfully replaced with cultivated Sphagnum. Non-sieved coarsely shredded Sphagnum or the large (> 6.3 mm fragments of sieved coarsely shredded Sphagnum best replicated the aeration provided by perlite and vermiculite in the substrates that were tested. Decomposition tests and comparisons of changes in physical properties of substrates containing Sphagnum after six weeks of growth trials indicated that Sphagnum degradation leading to reduced substrate performance is not likely to be an issue. Therefore, cultivated Sphagnum has great potential as a substitute for perlite and vermiculite.

  16. Susceptibilidad antimicrobiana de Staphylococcus aureus sensible, con sensibilidad "BORDERLINE" y resistentes a la meticilina

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Mendoza Ticona

    2003-10-01

    Full Text Available Objetivo: Determinar las susceptibilidad a diversos antibacterianos de tres categorías de S. aureus según su sensibilidad a la meticilina. Materiales y Métodos: Se aislaron 76 cepas de S. aureus que colonizaban pacientes y personal de salud de tres servicios del Hospital Honorio Delgado de Arequipa, de los cuales 36 fueron sensibles a meticilina (MSSA, 15 con susceptibilidad "borderline" (BORSA y 25 fueron resistentes a la meticilina (MRSA. Se les sometió a antibiograma a 14 antibacterianos. Resultados: El único antibiótico al cual todas los aislamientos fueron sensibles fue vancomicina. Los MRSA fueron resistentes a todos los b-lactámicos excepto imipenem que obtuvo 64% de susceptibilidad. Los BORSA mantuvieron un 80% de sensibilidad a cefalotina y un 100% al imipenem. Los antibióticos cefalotina, imipenem, ciprofloxacina, cotrimoxazol, rifampicina, eritromicina, tetraciclina, cloranfenicol, lincomicina y gentamicina tuvieron sensibilidades variables (p<0.01 entre las tres categorías; una mayor proporción de MSSA fue sensible a estos antibióticos, luego los BORSA y finalmente los MRSA. Las cepas multi-resistentes fueron mucho más frecuentes en los MRSA que en los otros dos grupos (p <0.01. Conclusión: Existe en nuestro medio cepas de S. aureus con resistencia "borderline" a meticilina. Hay diferencias entre la sensibilidad a diversos antimicrobianos entre los tres grupos de S. aureus. Esta diferenciación podría beneficiar una terapia antimicrobiana más racional. Se debe aplicar en todo aislamiento de S. aureus las recomendaciones internacionales para la detección de meticilino resistencia.

  17. Obras de fábrica resistentes. Consideraciones generales de cálculo

    Directory of Open Access Journals (Sweden)

    Jenaro Garrido, José María

    1986-10-01

    Full Text Available This work studies de resisting capacity of the non reinforced masonry works to normal requirements from the knowledge of the nominal value to compressive resistance of its elements, or from the results from compression tests carried out on masses or on masonry samples. The obtained expressions for homogeneous sections are also valid for sections that, because of their cavities, they can be considered heterogeneous, allowing a determination of its resistant behaviour by means of the introduction of the conceipt of resistant homogeneous equivalent section. Finaly it includes a study on deforming and buckling of the masonry works to which diverse expressions gathered already in the Model Code CEB-FIP and in the Instruction in force EH'82 for Concrete Works are applied.El presente artículo recoge un estudio de la capacidad resistente de las obras de fábrica no armadas ante las solicitaciones normales, a partir del conocimiento del valor nominal de la resistencia a compresión de los elementos componentes o de los resultados de ensayos a compresión realizados sobre macizos o probetas de obra de fábrica. Las expresiones obtenidas para secciones homogéneas se extienden a secciones que por comprender cavidades hayan de considerarse heterogéneas, haciendo posible una determinación de su comportamiento resistente mediante la introducción del concepto de sección resistente homogénea equivalente. Finalmente se incluye un estudio sobre la deformabilidad y pandeo de las obras de fábrica a los que se aplican diversas expresiones ya recogidas en el Código Modelo CEB-FIP y en la vigente Instrucción EH-82 para obras de hormigón.

  18. Clonal in vitro propagation of peat mosses (Sphagnum L.) as novel green resources for basic and applied research.

    Science.gov (United States)

    Beike, Anna K; Spagnuolo, Valeria; Lüth, Volker; Steinhart, Feray; Ramos-Gómez, Julia; Krebs, Matthias; Adamo, Paola; Rey-Asensio, Ana Isabel; Angel Fernández, J; Giordano, Simonetta; Decker, Eva L; Reski, Ralf

    As builders and major components of peatlands, Sphagnopsida (peat mosses) are very important organisms for ecosystems and world's climate. Nowadays many Sphagnum species as well as their habitats are largely protected, while their scientific and economic relevance remains considerable. Advanced methods of in vitro cultivation provide the potential to work in a sustainable way with peat mosses and address aspects of basic research as well as biotechnological and economical topics like biomonitoring or the production of renewable substrates for horticulture ( Sphagnum farming). Here, we describe the establishment of axenic in vitro cultures of the five peat moss species Sphagnum fimbriatum Wils. and Hook., Sphagnum magellanicum Brid., Sphagnum palustre L., Sphagnum rubellum Wils. and Sphagnum subnitens Russ. and Warnst. with specific focus on large-scale cultivation of S. palustre in bioreactors. Axenic, clonal cultures were established to produce high quantities of biomass under standardized laboratory conditions. For advanced production of S. palustre we tested different cultivation techniques, growth media and inocula, and analyzed the effects of tissue disruption. While cultivation on solid medium is suitable for long term storage, submerse cultivation in liquid medium yielded highest amounts of biomass. By addition of sucrose and ammonium nitrate we were able to increase the biomass by around 10- to 30-fold within 4 weeks. The morphology of in vitro-cultivated gametophores showed similar phenotypic characteristics compared to material from the field. Thus the tested culture techniques are suitable to produce S. palustre material for basic and applied research.

  19. Nutrient additions in pristine Patagonian Sphagnum bog vegetation: can phosphorus addition alleviate (the effects of) increased nitrogen loads.

    Science.gov (United States)

    Fritz, C; van Dijk, G; Smolders, A J P; Pancotto, V A; Elzenga, T J T M; Roelofs, J G M; Grootjans, A P

    2012-05-01

    Sphagnum-bog ecosystems have a limited capability to retain carbon and nutrients when subjected to increased nitrogen (N) deposition. Although it has been proposed that phosphorus (P) can dilute negative effects of nitrogen by increasing biomass production of Sphagnum mosses, it is still unclear whether P-addition can alleviate physiological N-stress in Sphagnum plants. A 3-year fertilisation experiment was conducted in lawns of a pristine Sphagnum magellanicum bog in Patagonia, where competing vascular plants were practically absent. Background wet deposition of nitrogen was low (≈ 0.1-0.2 g · N · m(-2) · year(-1)). Nitrogen (4 g · N · m(-2) · year(-1)) and phosphorus (1 g · P · m(-2) · year(-1)) were applied, separately and in combination, six times during the growing season. P-addition substantially increased biomass production of Sphagnum. Nitrogen and phosphorus changed the morphology of Sphagnum mosses by enhancing height increment, but lowering moss stem density. In contrast to expectations, phosphorus failed to alleviate physiological stress imposed by excess nitrogen (e.g. amino acid accumulation, N-saturation and decline in photosynthetic rates). We conclude that despite improving growth conditions by P-addition, Sphagnum-bog ecosystems remain highly susceptible to nitrogen additions. Increased susceptibility to desiccation by nutrients may even worsen the negative effects of excess nitrogen especially in windy climates like in Patagonia. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe.

    Science.gov (United States)

    Jiroušek, Martin; Hájek, Michal; Bragazza, Luca

    2011-02-01

    We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m(-2) year(-1) in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Long-term interactive effects of N addition with P and K availability on N status of Sphagnum.

    Science.gov (United States)

    Chiwa, Masaaki; Sheppard, Lucy J; Leith, Ian D; Leeson, Sarah R; Tang, Y Sim; Neil Cape, J

    2018-06-01

    Little information exists concerning the long-term interactive effect of nitrogen (N) addition with phosphorus (P) and potassium (K) on Sphagnum N status. This study was conducted as part of a long-term N manipulation on Whim bog in south Scotland to evaluate the long-term alleviation effects of phosphorus (P) and potassium (K) on N saturation of Sphagnum (S. capillifolium). On this ombrotrophic peatland, where ambient deposition was 8 kg N ha -1 yr -1 , 56 kg N ha -1 yr -1 of either ammonium (NH 4 + , N red ) or nitrate (NO 3 - , N ox ) with and without P and K, were added over 11 years. Nutrient concentrations of Sphagnum stem and capitulum, and pore water quality of the Sphagnum layer were assessed. The N-saturated Sphagnum caused by long-term (11 years) and high doses (56 kg N ha -1 yr -1 ) of reduced N was not completely ameliorated by P and K addition; N concentrations in Sphagnum capitula for N red 56 PK were comparable with those for N red 56, although N concentrations in Sphagnum stems for N red 56 PK were lower than those for N red 56. While dissolved inorganic nitrogen (DIN) concentrations in pore water for N red 56 PK were not different from N red 56, they were lower for N ox 56 PK than for N ox 56 whose stage of N saturation had not advanced compared to N red 56. These results indicate that increasing P and K availability has only a limited amelioration effect on the N assimilation of Sphagnum at an advanced stage of N saturation. This study concluded that over the long-term P and K additions will not offset the N saturation of Sphagnum. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Response of a Sphagnum bog plant community to elevated CO2 and N supply

    NARCIS (Netherlands)

    Heijmans, M.M.P.D.; Klees, H.; Visser, de W.; Berendse, F.

    2002-01-01

    The response of plant growth to rising CO2 levels appears to depend on nutrient availability, but it is not known whether the growth of bog plants reacts similarly. We therefore studied the effects of elevated CO2 in combination with N supply on the growth of Sphagnum mosses and vascular plants in

  3. Sphagnum mosses : Masters of efficient N-uptake while avoiding intoxication

    NARCIS (Netherlands)

    Fritz, Christian; Lamers, Leon P.M.; Riaz, Muhammed; van den Berg, Leon J.L.; Elzenga, Theo J.T.M.

    2014-01-01

    Peat forming Sphagnum mosses are able to prevent the dominance of vascular plants under ombrotrophic conditions by efficiently scavenging atmospherically deposited nitrogen (N). N-uptake kinetics of these mosses are therefore expected to play a key role in differential N availability, plant

  4. Sphagnum modifies climate-change impacts on subarctic vascular bog plants.

    NARCIS (Netherlands)

    Dorrepaal, E.; Aerts, R.; Cornelissen, J.H.C.; van Logtestijn, R.S.P; Callaghan, T.V.

    2006-01-01

    1. Vascular plant growth forms in northern peatlands differ in their strategies to cope with the harsh climate, low nutrient availability and progressively increasing height of the Sphagnum carpet in which they grow. Climate change may therefore affect growth forms differentially, both directly and

  5. [Analysis of the bacterial community developing in the course of Sphagnum moss decomposition].

    Science.gov (United States)

    Kulichevskaia, I S; Belova, S E; Kevbrin, V V; Dedysh, S N; Zavarzin, G A

    2007-01-01

    Slow degradation of organic matter in acidic Sphagnum peat bogs suggests a limited activity of organotrophic microorganisms. Monitoring of the Sphagnum debris decomposition in a laboratory simulation experiment showed that this process was accompanied by a shift in the water color to brownish due to accumulation of humic substances and by the development of a specific bacterial community with a density of 2.4 x 10(7) cells ml(-1). About half of these organisms are metabolically active and detectable with rRNA-specific oligonucleotide probes. Molecular identification of the components of this microbial community showed the numerical dominance of bacteria affiliated with the phyla Alphaproteobacteria, Actinobacteria, and Phanctomycetes. The population sizes of Firmicutes and Bacteroidetes, which are believed to be the main agents of bacterially-mediated decomposition in eutrophic wetlands, were low. The numbers of planctomycetes increased at the final stage of Sphagnum decomposition. The representative isolates of Alphaproteobacteria were able to utilize galacturonic acid, the only low-molecular-weight organic compound detected in the water samples; the representatives of Planctomycetes were able to decompose some heteropolysaccharides, which points to the possible functional role of these groups of microorganisms in the community under study. Thus, the composition of the bacterial community responsible for Sphagnum decomposition in acidic and low-mineral oligotrophic conditions seems to be fundamentally different from that of the bacterial community which decomposes plant debris in eutrophic ecosystems at neutral pH.

  6. The trapping of fly-ash particles in the surface layers of Sphagnum-dominated peat

    International Nuclear Information System (INIS)

    Punning, J.-M.; Alliksaar, T.

    1997-01-01

    The movement of fly-ash particles in a sequence of Sphagnum moss was studied in laboratory experiments and field investigations. Fly ash was obtained from the electrostatic precipitators of the Estonian Thermal Power Plant operating on oil shale. The data obtained in the laboratory show that only 0.8% of particles, placed on the surface of a 6-10 cm thick Sphagnum layer, were washed out with water (700-750 mm) during the 241 days of the experiment. The majority of added particles were fixed in the upper part (90% in 1-3 cm) of the moss layer. A SEM study indicates that sorption is slightly species-dependent due to the micromorphological parameters of the Sphagnum species. The storage of particles by Sphagnum mosses allows the use of natural sequences to study the history of atmospheric pollution. The distribution of particles in the upper part of moss layers in Viru Bog (50 km east of Tallinn, North Estonia) shows good agreement with the known air pollution history in Tallinn. 13 refs., 6 figs., 2 tabs

  7. The interaction between epiphytic algae, a parasitic fungus and Sphagnum as affected by N. and P.

    NARCIS (Netherlands)

    Limpens, J.; Jeffrey, T.A.G.; Baar, J.; Berendse, F.; Zijlstra, J.D.

    2003-01-01

    We report the effects of fertilisation with N and P on the infection of Sphagnum by its fungal parasite Lyophyllum palustre, the expansion of epiphytic algae and the interaction between the latter two from 1998 to 2001. We added 40 kg N ha(-1) yr(-1) or 3 kg P ha(-1) yr(-1) in a full factorial

  8. Exploding a myth: the capsule dehiscence mechanism and the function of pseudostomata in Sphagnum.

    Science.gov (United States)

    Duckett, Jeffrey G; Pressel, Silvia; P'ng, Ken M Y; Renzaglia, Karen S

    2009-01-01

    The nineteenth century air-gun explanation for explosive spore discharge in Sphagnum has never been tested experimentally. Similarly, the function of the numerous stomata ubiquitous in the capsule walls has never been investigated. Both intact and pricked Sphagnum capsules, that were allowed to dry out, all dehisced over an 8-12 h period during which time the stomatal guard cells gradually collapsed and their potassium content, measured by X-ray microanalysis in a cryoscanning electron microscope, gradually increased. By contrast, guard cell potassium fell in water-stressed Arabidopsis. The pricking experiments demonstrate that the air-gun notion for explosive spore discharge in Sphagnum is inaccurate; differential shrinkage of the capsule walls causes popping off the rigid operculum. The absence of evidence for a potassium-regulating mechanism in the stomatal guard cells and their gradual collapse before spore discharge indicates that their sole role is facilitation of sporophyte desiccation that ultimately leads to capsule dehiscence. Our novel functional data on Sphagnum, when considered in relation to bryophyte phylogeny, suggest the possibility that stomata first appeared in land plants as structures that facilitated sporophyte drying out before spore discharge and only subsequently acquired their role in the regulation of gaseous exchange.

  9. Decomposition of Carex and Sphagnum litter in two mesotrophic fens differing in dominant plant species

    NARCIS (Netherlands)

    Scheffer, R.A.; Van Logtestijn, R. S P; Verhoeven, J. T A

    2001-01-01

    Peatlands can be classified into fens and bogs based on their hydrology. Development of fens to bogs is accompanied by the invasion of Sphagnum species. The purpose of this study was to determine how the decomposition process in fens is influenced by the transition from a vascular plant-dominated

  10. Ecohydrology of a Sphagnum peatland in transitional climate - an interdysciplinary study

    Science.gov (United States)

    Słowińska, S.; Słowiński, M.; Lamentowicz, M.; Skrzypek, G.

    2012-04-01

    Sphagnum peatlands of the Central Europe are regarded as the valuable and endangered habitats. Their existence depends on the complex climatic, hydrological, topographical and botanical conditions. Good understanding of peatlands' ecohydrology is crucial for the appropriate environmental management. Our long-term ecological study is focused on a poor fen located in Northern Poland - a unique floristic nature reserve and Nature 2000 area. Main aims of the research were to: a) understand an influence of the temperature and precipitation on the ground water, b) explain an impact of the local climate and the groundwater table level on testate amoebae communities, Sphagnum mosses growth and stable carbon, nitrogen and oxygen isotope compositions, c) use the neo- ecological data for the quantitative palaeoecological reconstructions. We have been conducting the monitoring of the growth of Sphagnum mosses in five plots. Vegetation was sampled three times during the growing season for the stable isotope and testate amoebae analyses (July, September and December 2009). Temperature of the air and acrotelm, air humidity, precipitation and groundwater table were recorded using automatic data loggers. Our research confirmed that even small fluctuation of temperature, precipitation and annual distribution of precipitation have a very strong impact on the hydrology of the peatland. Testate amoeba communities and stable isotopes from Sphagnum clearly indicated the hydrological response of the mire in the different parts of the peatland. The next step is a detailed seasonal study supported by the manipulative warming experiment.

  11. Response of Sphagnum species mixtures to increased temperature and nitrogen availability

    NARCIS (Netherlands)

    Breeuwer, A.J.G.; Heijmans, M.M.P.D.; Berendse, F.; Gleichman, J.M.; Robroek, B.J.M.; Limpens, J.

    2009-01-01

    To predict the role of ombrotrophic bogs as carbon sinks in the future, it is crucial to understand how Sphagnum vegetation in bogs will respond to global change. We performed a greenhouse experiment to study the effects of two temperature treatments (17.5 and 21.7°C) and two N addition treatments

  12. Expansion of Sphagnum fallax in bogs: striking the ballance between N and P availability

    NARCIS (Netherlands)

    Limpens, J.; Tomassen, H.B.M.; Berendse, F.

    2003-01-01

    Nitrogen deposition may cause shifts in the Sphagnum species composition of bogs, ultimately affecting the conservation value of these systems. We studied the effects of N and P on the expansion of S. fallax and S. flexuosum in bogs. We related historical census data of S. fallax, S. flexuosum, and

  13. Major and trace elements in Sphagnum moss from four southern German bogs, and comparison with available moss monitoring data

    OpenAIRE

    KEMPTER HEIKE; KRACHLER MICHAEL; SHOTYK W.; ZACCONE CLAUDIO

    2017-01-01

    In this paper, we present concentrations of an array of major and trace elements (Ag, Al, As, Ba, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Rb, Sb, Sc, Sr, Th, Tl, U, V, Zn) in living Sphagnum mosses from four southern German bogs and compare them with moss monitoring data of the respective regions. To do this, Sphagnum mosses were collected in Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and, one year la...

  14. Sphagnum mosses--masters of efficient N-uptake while avoiding intoxication.

    Science.gov (United States)

    Fritz, Christian; Lamers, Leon P M; Riaz, Muhammad; van den Berg, Leon J L; Elzenga, Theo J T M

    2014-01-01

    Peat forming Sphagnum mosses are able to prevent the dominance of vascular plants under ombrotrophic conditions by efficiently scavenging atmospherically deposited nitrogen (N). N-uptake kinetics of these mosses are therefore expected to play a key role in differential N availability, plant competition, and carbon sequestration in Sphagnum peatlands. The interacting effects of rain N concentration and exposure time on moss N-uptake rates are, however, poorly understood. We investigated the effects of N-concentration (1, 5, 10, 50, 100, 500 µM), N-form ((15)N-ammonium or nitrate) and exposure time (0.5, 2, 72 h) on uptake kinetics for Sphagnum magellanicum from a pristine bog in Patagonia (Argentina) and from a Dutch bog exposed to decades of N-pollution. Uptake rates for ammonium were higher than for nitrate, and N-binding at adsorption sites was negligible. During the first 0.5 h, N-uptake followed saturation kinetics revealing a high affinity (Km 3.5-6.5 µM). Ammonium was taken up 8 times faster than nitrate, whereas over 72 hours this was only 2 times. Uptake rates decreased drastically with increasing exposure times, which implies that many short-term N-uptake experiments in literature may well have overestimated long-term uptake rates and ecosystem retention. Sphagnum from the polluted site (i.e. long-term N exposure) showed lower uptake rates than mosses from the pristine site, indicating an adaptive response. Sphagnum therefore appears to be highly efficient in using short N pulses (e.g. rainfall in pristine areas). This strategy has important ecological and evolutionary implications: at high N input rates, the risk of N-toxicity seems to be reduced by lower uptake rates of Sphagnum, at the expense of its long-term filter capacity and related competitive advantage over vascular plants. As shown by our conceptual model, interacting effects of N-deposition and climate change (changes in rainfall) will seriously alter the functioning of Sphagnum peatlands.

  15. Sphagnum Mosses - Masters of Efficient N-Uptake while Avoiding Intoxication

    Science.gov (United States)

    Fritz, Christian; Lamers, Leon P. M.; Riaz, Muhammad; van den Berg, Leon J. L.; Elzenga, Theo J. T. M.

    2014-01-01

    Peat forming Sphagnum mosses are able to prevent the dominance of vascular plants under ombrotrophic conditions by efficiently scavenging atmospherically deposited nitrogen (N). N-uptake kinetics of these mosses are therefore expected to play a key role in differential N availability, plant competition, and carbon sequestration in Sphagnum peatlands. The interacting effects of rain N concentration and exposure time on moss N-uptake rates are, however, poorly understood. We investigated the effects of N-concentration (1, 5, 10, 50, 100, 500 µM), N-form (15N - ammonium or nitrate) and exposure time (0.5, 2, 72 h) on uptake kinetics for Sphagnum magellanicum from a pristine bog in Patagonia (Argentina) and from a Dutch bog exposed to decades of N-pollution. Uptake rates for ammonium were higher than for nitrate, and N-binding at adsorption sites was negligible. During the first 0.5 h, N-uptake followed saturation kinetics revealing a high affinity (Km 3.5–6.5 µM). Ammonium was taken up 8 times faster than nitrate, whereas over 72 hours this was only 2 times. Uptake rates decreased drastically with increasing exposure times, which implies that many short-term N-uptake experiments in literature may well have overestimated long-term uptake rates and ecosystem retention. Sphagnum from the polluted site (i.e. long-term N exposure) showed lower uptake rates than mosses from the pristine site, indicating an adaptive response. Sphagnum therefore appears to be highly efficient in using short N pulses (e.g. rainfall in pristine areas). This strategy has important ecological and evolutionary implications: at high N input rates, the risk of N-toxicity seems to be reduced by lower uptake rates of Sphagnum, at the expense of its long-term filter capacity and related competitive advantage over vascular plants. As shown by our conceptual model, interacting effects of N-deposition and climate change (changes in rainfall) will seriously alter the functioning of Sphagnum peatlands

  16. Fagotipagem de cepas de Staphylococcus aureus resistentes a antibióticos, isoladas de leite

    Directory of Open Access Journals (Sweden)

    Wanderley Pereira de Araújo

    1998-01-01

    Full Text Available A partir de amostras de leite cru foram isoladas 201 cepas de S. aureus, as quais foram submetidas a provas de resistência a antibióticos pelo método dos discos impregnados com os seguintes antibacterianos: amicacina, ampicilina, cefalotina, cefoxitina, cloranfenicol, clindamicina, oxacilina, penicilina, tetraciclina, tobramicina e vancomicina. Com exceção de 88 (43,8%, 90 (44,8%, 24 (11,9% e 40 (19,9% cepas resistentes à penicilina, ampicilina, cloranfenicol e tetraciclina, respectivamente, a maioria das 201 cepas (95% ou mais foi sensível aos antibióticos utilizados. As cepas resistentes a estes quatro antibióticos foram fagotipadas, empregando-se os Conjuntos Básicos Internacionais de bacteriófagos para cepas de origem humana e bovina, verificando-se que houve predomínio de cepas sensíveis a fagos dos grupos III e III/NC do conjunto básico humano e a fagos dos grupos III, IV e da associação III/IV do conjunto bovino.

  17. Estrategias de afrontamiento y personalidad resistente en pacientes de cuidados paliativos. Un estudio preliminar

    Directory of Open Access Journals (Sweden)

    CECILIA PEÑACOBA PUENTE

    2005-01-01

    Full Text Available La medicina paliativa se dedica al cuidado de los pacientes con enfermedades en fase terminal. En España, existen varias unidades de cuidados paliativos, sin embargo, no en todas se lleva a cabo una intervención multidisciplinaria lo cual es esencial para conseguir que una persona muera en una situación de bienestar y con la mejor calidad posible. El objetivo de este estudio es analizar las estrategias de afrontamiento existentes en los enfermos ingresados en unidades de cuidados paliativos en fase de aceptación y su relación con la personalidad resistente. Para ello, se administró un instrumento corto en forma de entrevista. Los resultados encontrados muestran que este tipo de pacientes utilizan estrategias de afrontamiento positivas como acción para resolver problemas, búsqueda de recompensas alternativas y reevaluación positiva. Por otro lado, un aspecto de la personalidad resistente encontrada en estos pacientes es el reto lo cual indica que estos pacientes viven esta experiencia como una oportunidad de desarrollo personal.

  18. TERAPIA FOTODINÂMICA COM AZUL DE METILENO SOBRE CEPA DE Staphylococcus aureus RESISTENTE À METICILINA

    Directory of Open Access Journals (Sweden)

    Mirian Alves Freitas

    2017-01-01

    Full Text Available S. aureus é o agente etiológico de maior importância associado às infecções adquiridas tanto em âmbito comunitário ou hospitalar, devido a sua capacidade de desenvolver resistência às terapias convencionais. A Terapia Fotodinâmica (TFD surge como alternativa a ser utilizada no controle de cepas resistentes aos antibioticos. O objetivo do presente estudo é avaliar os efeitos da TFD com Azul de Metileno (AM sobre cepas de S. aureus resistente à meticilina (MRSA. As amostras foram diluídas em PBS estéril de acordo com a escala 0,5 de MacFarland. Os grupos foram compostos com diferentes concentrações de AM, incubados no escuro durante 15 minutos e irradiados por LED Biopdi/Irrad-Led5 em 660nm com fluência de 10 J/cm². Posteriormente, foram semeadas e incubadas à 37ºC por 24 horas. A contagem de Unidades Formadoras de Colônias (UFCs demonstrou que a TFD foi eficaz na menor concentração testada de AM sobre cepas de MRSA.

  19. Physiological responses to nitrogen and sulphur addition and raised temperature in Sphagnum balticum.

    Science.gov (United States)

    Granath, Gustaf; Wiedermann, Magdalena M; Strengbom, Joachim

    2009-09-01

    Sphagnum, the main genus which forms boreal peat, is strongly affected by N and S deposition and raised temperature, but the physiological mechanisms behind the responses are largely unknown. We measured maximum photosynthetic rate (NP(max)), maximum efficiency of photosystem II [variable fluorescence (F (v))/maximum fluorescence yield (F (m))] and concentrations of N, C, chlorophyll and carotenoids as responses to N and S addition and increased temperature in Sphagnum balticum (a widespread species in the northern peatlands) in a 12-year factorial experiment. NP(max) did not differ between control (0.2 g N m(-2) year(-1)) and high N (3.0 g N m(-2) year(-1)), but was higher in the mid N treatment (1.5 g N m(-2) year(-1)). N, C, carotenoids and chlorophyll concentration increased in shoot apices after N addition. F (v)/F (m) did not differ between N treatments. Increased temperature (+3.6 degrees C) had a small negative effect on N concentration, but had no significant effect on NP(max) or F (v)/F (m). Addition of 2 g S m(-2) year(-1) showed a weak negative effect on NP(max) and F (v)/F (m). Our results suggest a unimodal response of NP(max) to N addition and tissue N concentration in S. balticum, with an optimum N concentration for photosynthetic rate of ~13 mg N g(-1). In conclusion, high S deposition may reduce photosynthetic capacity in Sphagnum, but the negative effects may be relaxed under high N availability. We suggest that previously reported negative effects on Sphagnum productivity under high N deposition are not related to negative effects on the photosynthetic apparatus, but differences in optimum N concentration among Sphagnum species may affect their competitive ability under different N deposition regimes.

  20. Metal and proton adsorption capacities of natural and cloned Sphagnum mosses.

    Science.gov (United States)

    Gonzalez, Aridane G; Pokrovsky, Oleg S; Beike, Anna K; Reski, Ralf; Di Palma, Anna; Adamo, Paola; Giordano, Simonetta; Angel Fernandez, J

    2016-01-01

    Terrestrial mosses are commonly used as bioindicators of atmospheric pollution. However, there is a lack of standardization of the biomonitoring preparation technique and the efficiency of metal adsorption by various moss species is poorly known. This is especially true for in vitro-cultivated moss clones, which are promising candidates for a standardized moss-bag technique. We studied the adsorption of copper and zinc on naturally grown Sphagnum peat moss in comparison with in vitro-cultivated Sphagnum palustre samples in order to provide their physico-chemical characterization and to test the possibility of using cloned peat mosses as bioindicators within the protocol of moss-bag technique. We demonstrate that in vitro-grown clones of S. palustre exhibit acid-base properties similar to those of naturally grown Sphagnum samples, whereas the zinc adsorption capacity of the clones is approx. twice higher than that of the samples from the field. At the same time, the field samples adsorbed 30-50% higher amount of Cu(2+) compared to that of the clones. This contrast may be related to fine differences in the bulk chemical composition, specific surface area, morphological features, type and abundance of binding sites at the cell surfaces and in the aqueous solution of natural and cloned Sphagnum. The clones exhibited much lower concentration of most metal pollutants in their tissues relative to the natural samples thus making the former better indicators of low metal loading. Overall, in vitro-produced clones of S. palustre can be considered as an adequate, environmentally benign substitution for protected natural Sphagnum sp. samples to be used in moss-bags for atmospheric monitoring. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Alternative substrates to the sphagnum moss in the acclimatization of arundina graminifolia “alba”(Orchidaceae

    Directory of Open Access Journals (Sweden)

    Ana Paula Zandoná

    2014-09-01

    Full Text Available The Arundina graminifolia, is popularly known as bamboo orchid, by having their stems quite extensive. It is widely used in the business landscape, with a very rustic plant. Sphagnum moss is the most widely used substrate in the acclimatization of orchids, but environmental issues have led to an increase in the search for alternative substrates. The objective of this study was to evaluate substrates that can replace all or part of the use of sphagnum moss on the acclimatization of A. graminifolia. The substrates used were: sphagnum moss, rice hulls, rice hulls + coir 1:1 (v / v sphagnum + carbonized rice husk, 1:1 (v / v. Seedlings were kept in a greenhouse and after seven months were evaluated for survival rate (%, shoot height (cm, average root length (cm, number of leaves and roots, dry leaves, pseudobulbs and roots (g and leaf area (mm2. Also evaluated were pH, conductivity (uS.cm-1, density (g.cm-3 and water holding capacity (mL.L-1 were evaluated. The results showed high levels of survival (80% and the number of leaves (4.3 grown plants in rice hulls + coconut fiber 1:1 (v / v. The same with respect to pH (5.9 within the optimal range of nutrient availability. It is concluded that the mixture of rice hulls + coconut fiber 1:1 (v / v, is a suitable substrate for plant growth A. graminifolia during the acclimatization phase, which may replace the sphagnum, and the use of carbonized rice husk alone unfeasible during this period.

  2. A Novel Framework for Quantifying past Methane Recycling by Sphagnum-Methanotroph Symbiosis Using Carbon and Hydrogen Isotope Ratios of Leaf Wax Biomarkers

    Science.gov (United States)

    Nichols, Jonathan E.; Isles, Peter D. F.; Peteet, Dorothy M.

    2014-01-01

    The concentration of atmospheric methane is strongly linked to variations in Earth's climate. Currently, we can directly reconstruct the total atmospheric concentration of methane, but not individual terms of the methane cycle. Northern wetlands, dominated by Sphagnum, are an important contributor of atmospheric methane, and we seek to understand the methane cycle in these systems. We present a novel method for quantifying the proportion of carbon Sphagnum assimilates from its methanotrophic symbionts using stable isotope ratios of leaf-wax biomarkers. Carbon isotope ratios of Sphagnum compounds are determined by two competing influences, water content and the isotope ratio of source carbon. We disentangled these effects using a combined hydrogen and carbon isotope approach. We constrained Sphagnum water content using the contrast between the hydrogen isotope ratios of Sphagnum and vascular plant biomarkers. We then used Sphagnum water content to calculate the carbon isotope ratio of Sphagnum's carbon pool. Using a mass balance equation, we calculated the proportion of recycled methane contributed to the Sphagnum carbon pool, 'PRM.' We quantified PRM in peat monoliths from three microhabitats in the Mer Bleue peatland complex. Modern studies have shown that water table depth and vegetation have strong influences on the peatland methane cycle on instrumental time scales. With this new approach, delta C-13 of Sphagnum compounds are now a useful tool for investigating the relationships among hydrology, vegetation, and methanotrophy in Sphagnum peatlands over the time scales of entire peatland sediment records, vital to our understanding of the global carbon cycle through the Late Glacial and Holocene.

  3. Validating modelled data on major and trace element deposition in southern Germany using Sphagnum moss

    Science.gov (United States)

    Kempter, Heike; Krachler, Michael; Shotyk, William; Zaccone, Claudio

    2017-10-01

    Sphagnum mosses were collected from four ombrotrophic bogs in two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and, one year later, plant matter was harvested and productivity determined. Major and trace element concentrations (Ag, Al, As, Ba, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Rb, Sb, Sc, Sr, Th, Ti, Tl, U, V, Zn) were determined in acid digests using sector field ICP-MS. Up to 12 samples (40 × 40 cm) were collected per site, and 6-10 sites investigated per bog. Variation in element accumulation rates within a bog is mostly the result of the annual production rate of the Sphagnum mosses which masks not only the impact of site effects, such as microtopography and the presence of dwarf trees, but also local and regional conditions, including land use in the surrounding area, topography, etc. The difference in productivity between peat bogs results in distinctly higher element accumulation rates at the NBF bogs compared to those from OB for all studied elements. The comparison with the European Monitoring and Evaluation Program (EMEP; wet-only and total deposition) and Modelling of Air Pollutants and Ecosystem Impact (MAPESI; total deposition) data shows that accumulation rates obtained using Sphagnum are in the same range of published values for direct measurements of atmospheric deposition of As, Cd, Cu, Co, Pb, and V in both regions. The accordance is very dependent on how atmospheric deposition rates were obtained, as different models to calculate the deposition rates may yield different fluxes even for the same region. In future studies of atmospheric deposition of trace metals, both Sphagnum moss and deposition collectors have to be used on the same peat bog and results compared. Antimony, however, shows considerable discrepancy, because it is either under-estimated by Sphagnum moss or over-estimated by both atmospheric deposition

  4. Factores de riesgo para bacteriemia por Pseudomonas aeruginosa resistente a carbapenémicos adquirida en un hospital colombiano

    Directory of Open Access Journals (Sweden)

    Sandra Liliana Valderrama

    2016-04-01

    Conclusión. Para el control de la aparición de P. aeruginosa resistente a carbapenémicos, se deben fortalecer los programas de control de antimicrobianos, promover el uso prudente de carbapenémicos y quinolonas, y vigilar el uso adecuado de la nutrición parenteral.

  5. Manejo de Conyza bonariensis resistente ao herbicida glyphosate Management of Glyphosate-resistant Conyza bonariensis

    Directory of Open Access Journals (Sweden)

    J.M. Paula

    2011-03-01

    Full Text Available C. bonariensis (Conyza bonariensis é uma planta daninha da família Asteraceae, amplamente distribuída no Brasil, com presença marcante nos Estados do Rio Grande do Sul e do Paraná. Biótipos de C. bonariensis resistentes ao glyphosate foram identificados nos Estados do Rio Grande do Sul, Paraná e São Paulo. O objetivo deste trabalho foi avaliar o efeito de diferentes manejos de inverno e na pré-semeadura da soja sobre a população de plantas de C. bonariensis resistente ao herbicida glyphosate. Os resultados evidenciaram que a população de C. bonariensis é maior em áreas mantidas sem cultivo (pousio do que naquelas áreas cultivadas com trigo ou aveia-preta durante o inverno. Observou-se que o trigo e a aveia-preta exercem efeito supressor sobre a população de C. bonariensis, proporcionando maior facilidade de controle com herbicida na pré-semeadura da cultura usada em sucessão. O controle de C. bonariensis resistente ao herbicida glyphosate foi satisfatório quando se utilizaram herbicidas pós-emergentes na cultura do trigo e glyphosate + 2,4-D ou glyphosate + diuron + paraquat na pré-semeadura da soja.Horseweed (Conyza bonariensis, which belongs to the Asteraceae family, is a weed species widely spread in Brazil. Horseweed biotypes resistant to glyphosate, the main herbicide used in Roundup Ready soybean fields, were identified in the states of Rio Grande do Sul and Parana. The aim of this study was to evaluate the effect of different winter and pre-sowing management techniques on soybean plant population of C. bonariensis resistant to glyphosate. The results showed that the population of C. bonariensis is larger in areas maintained fallow than in areas planted with wheat or oats during the winter. Wheat and oats were found to exert a suppressive effect on the population of C. bonariensis, providing greater ease of control with herbicide before seeding in the culture used in succession. The control of glyphosate-resistant C

  6. Establishing Sphagnum cultures on bog grassland, cut-over bogs, and floating mats: procedures, costs and area potential in Germany

    Directory of Open Access Journals (Sweden)

    S. Wichmann

    2017-04-01

    Full Text Available Sphagnum biomass is valued as a high-quality constituent of horticultural growing media. The cultivation of Sphagnum (peatmoss was tested successfully on peat soil and on artificial mats floating on acidic water bodies. But whether Sphagnum farming is economically feasible is unclear. Drawing on experience gained during four research projects in Germany we compared the procedures, costs and area potential for establishing large-scale Sphagnum cultures. Establishment costs were clearly lower for soil-based cultivation (€8.35 m-2 to €12.80 m 2 than for water-based cultivation (€17.34 m-2 to €21.43 m-2. Relating costs to the predicted dry mass yield over the total cultivation time resulted in values of €1,723 t-1 on cut-over bog, €2,646 t-1 on former bog grassland, €9,625 t -1 on floating mats without pre-cultivation and €11,833 t-1 on pre-cultivated Sphagnum mats. The high production costs of the mats (without pre-cultivation 54 % and with pre-cultivation 63 % of total costs resulted in the highest overall costs. In the case of soil-based Sphagnum cultures, the costs of purchasing Sphagnum diaspores were most influential (on bog grassland 46 % and on cut-over bog 71 % of total costs. The lowest costs relate to cut-over bog because of the smaller effort required for site preparation compared to taking off the topsoil of former bog grassland and the limited costs for the assumed irrigation system. In the case of former bog grassland, the high investment costs for the project-specific automatic water management boosted the establishment costs. Taking into account potential savings on the irrigation system and the high area potential, bog grassland emerges as the most promising land category for Sphagnum farming in Germany.

  7. Relative importance of local habitat complexity and regional factors for assemblages of oribatid mites (Acari: Oribatida) in Sphagnum peat bogs.

    Science.gov (United States)

    Minor, M A; Ermilov, S G; Philippov, D A; Prokin, A A

    2016-11-01

    We investigated communities of oribatid mites in five peat bogs in the north-west of the East European plain. We aimed to determine the extent to which geographic factors (latitude, separation distance), local environment (Sphagnum moss species, ground water level, biogeochemistry) and local habitat complexity (diversity of vascular plants and bryophytes in the surrounding plant community) influence diversity and community composition of Oribatida. There was a significant north-to-south increase in Oribatida abundance. In the variance partitioning, spatial factors explained 33.1 % of variability in abundance across samples; none of the environmental factors were significant. Across all bogs, Oribatida species richness and community composition were similar in Sphagnum rubellum and Sphagnum magellanicum, but significantly different and less diverse in Sphagnum cuspidatum. Sphagnum microhabitat explained 52.2 % of variability in Oribatida species richness, whereas spatial variables explained only 8.7 %. There was no distance decay in community similarity between bogs with increased geographical distance. The environmental variables explained 34.9 % of the variance in community structure, with vascular plants diversity, bryophytes diversity, and ground water level all contributing significantly; spatial variables explained 15.1 % of the total variance. Overall, only 50 % of the Oribatida community variance was explained by the spatial structure and environmental variables. We discuss relative importance of spatial and local environmental factors, and make general inferences about the formation of fauna in Sphagnum bogs.

  8. Effect of crustose lichen on soil CO2 efflux in sphagnum moss regime of tundra, west Alaska

    Science.gov (United States)

    Kim, Y.; Park, S. J.; Suzuki, R.; Lee, B. Y.

    2017-12-01

    Increasing ambient temperatures across the Arctic have induced changes in plant extent and phenology, degradation of permafrost, snow depth and covered extent, decomposition of soil organic matter, and subsequently, soil carbon emission to the atmosphere. However, there is fully not understood on the effect of crustose lichen on soil CO2 emission to the atmosphere. Although the spores of lichen are spread by wind and animals, the crustose lichen is infected to the only sphagnum moss widely distributed in the Arctic, and is terminally killed the moss. Here, we report the research findings on the soil CO2 efflux-measurement with forced diffusion (FD) chamber system that is continuously monitored in sphagnum moss regime of west Alaska for the growing season of 2016. The environmental parameters (e.g., soil temperature and moisture) were measured at intact and infected sphagnum moss regime. The FD chamber is measured at an interval of 10-min and 30-min, which is not significant difference between both intervals (R2 = 0.94; n = 1360; RMSE = 0.043; p sphagnum moss, and 0.27(0.47), 0.45(0.17), 0.50(0.22), and 0.31(0.49) in intact sphagnum moss, respectively. This finding demonstrates that 1) soil CO2 in infected sphagnum moss is one of atmospheric CO2 source in June and July, and 2) soil CO2 efflux is not significant difference between both regimes for August and September of 2016.

  9. Endocardite acuta da Staphylococcus haemolyticus meticillino sensibile, con recidiva dopo trattamento da ceppo meticillino resistente

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    Giacomo Magnani

    2005-03-01

    Full Text Available Le endocarditi su valvole native (NVE da Stafilococchi coagulasi negativi (CoNS presentano un andamento aggressivo simile a quello da Staphylococcus aureus e sono difficili da trattare per l’alta incidenza da parte dei CoNS di resistenza a oxacillina.Viene riportato un caso di NVE da Staphylococcus haemolyticus meticillino sensibile, con risposta iniziale favorevole al trattamento con oxacillina, ma con successiva recidiva a distanza di tre mesi legata comparsa di ceppo oxacillino-resistente. L’ipotesi è che l’infezione sia stata sostenuta da una popolazione batterica con fenotipo eteroresistente, che in seguito al trattamento antibiotico ha sviluppato resistenza omogenea a oxacillina. Nell’impostare un trattamento per infezioni gravi da Stafilococchi sensibili in vitro ad oxacillina è necessario considerare sempre la presenza di un eteroresistenza.

  10. Cepas de Campylobacter jejuni resistentes a quinolonas aisladas de humanos, gallinas y pollos

    Directory of Open Access Journals (Sweden)

    Rodolfo Notario

    2011-08-01

    Full Text Available Se compararon 8 aislamientos de Campylobacter jejuni provenientes de humanos con enfermedad diarreica aguda, con 23 aislamientos de cloaca de gallinas y pollos obtenidos de zonas próximas a la ciudad de Rosario, todos resistentes a la ciprofloxacina. Las muestras se sembraron en agar selectivo y se incubaron en microaerofilia a 42 °C. Las colonias se identificaron con el método tradicional. Los aislamientos se conservaron a -70 °C en caldo cerebro corazón con 17% v/v de glicerina. La clonalidad se determinó por RAPD-PCR, utilizando el primer 1254 (Stern NJ. Se interpretaron los aislamientos como clones distintos cuando diferían en una banda de amplificación. Se obtuvieron 5 clones diferentes. Los patrones I, II y V fueron aislados en criaderos industriales de pollos y en humanos (el II también en un establecimiento de gallinas ponedoras de huevos. En un gallinero familiar se obtuvo el patrón I. El patrón III sólo se obtuvo de humanos. El patrón IV se halló en uno de los criaderos pero no en humanos. Se pudo determinar que 93.5% de las cepas se aislaron tanto de animales como de humanos, por lo que se considera posible que la colonización de criaderos con cepas resistentes a los antimicrobianos pudiera ser el origen de la infección de humanos.

  11. Effect of fire on phosphorus forms in Sphagnum moss and peat soils of ombrotrophic bogs.

    Science.gov (United States)

    Wang, Guoping; Yu, Xiaofei; Bao, Kunshan; Xing, Wei; Gao, Chuanyu; Lin, Qianxin; Lu, Xianguo

    2015-01-01

    The effect of burning Sphagnum moss and peat on phosphorus forms was studied with controlled combustion in the laboratory. Two fire treatments, a light fire (250 °C) and a severe fire (600 °C), were performed in a muffle furnace with 1-h residence time to simulate the effects of different forest fire conditions. The results showed that fire burning Sphagnum moss and peat soils resulted in losses of organic phosphorus (Po), while inorganic phosphorus (Pi) concentrations increased. Burning significantly changed detailed phosphorus composition and availability, with severe fires destroying over 90% of organic phosphorus and increasing the availability of inorganic P by more than twofold. Our study suggest that, while decomposition processes in ombrotrophic bogs occur very slowly, rapid changes in the form and availability of phosphorus in vegetation and litter may occur as the result of forest fires on peat soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. [Effect of mechanical grinding of Sphagnum on the structure and physiological state of bacterial communities].

    Science.gov (United States)

    Dobrovol'skaya, T G; Golovchenko, A V; Yakushev, A V; Manucharova, N A; Yurchenko, E N

    2014-01-01

    The microcosm method was used to demonstrate an increase in bacterial numbers and drastic changes in the taxonomic structure of saprotrophic bacteria as a result of mechanical grinding of Sphagnum moss. Ekkrisotrophic agrobacteria predominant in untreated moss were replaced by hydrolytic bacteria. Molecular biological approaches revealed such specific hydrolytic bacteria as Janthinobacterium agaricum and Streptomyces purpurascens among the dominant taxa. The application of kinetic technique for determination of the physiological state of bacteria in situ revealed higher functional diversity of hydrolytic bacteria in ground moss than in untreated samples. A considerable decrease of the C/N ratio in ground samples of living Sphagnum incubated using the microcosm technique indicated decomposition of this substrate.

  13. The effect of elevated CO{sub 2} concentration on photosynthesis of Sphagnum fuscum

    Energy Technology Data Exchange (ETDEWEB)

    Jauhiainen, J; Silvola, J [Joensuu Univ. (Finland). Dept. of Biology

    1997-12-31

    The objectives of the research were to measure photosynthesis of Sphagnum fuscum in long term exposure to four CO{sub 2} levels at semi-natural conditions, to find out if there is an acclimation of net photosynthesis into prevailing CO{sub 2} concentrations and to measure the moisture dependent net photosynthesis at various CO{sub 2} concentrations of samples grown at different CO{sub 2} concentrations

  14. The effect of elevated CO{sub 2} concentration on photosynthesis of Sphagnum fuscum

    Energy Technology Data Exchange (ETDEWEB)

    Jauhiainen, J.; Silvola, J. [Joensuu Univ. (Finland). Dept. of Biology

    1996-12-31

    The objectives of the research were to measure photosynthesis of Sphagnum fuscum in long term exposure to four CO{sub 2} levels at semi-natural conditions, to find out if there is an acclimation of net photosynthesis into prevailing CO{sub 2} concentrations and to measure the moisture dependent net photosynthesis at various CO{sub 2} concentrations of samples grown at different CO{sub 2} concentrations

  15. Ozone effects on Sphagnum mosses, carbon dioxide exchange and methane emission in boreal peatland microcosms

    International Nuclear Information System (INIS)

    Niemi, Riikka; Holopainen, Toini; Martikainen, Pertti J.; Silvola, Jouko

    2002-01-01

    Microcosms of a boreal peatland originating from an oligotrophic fen in Eastern Finland were fumigated under four ozone concentrations (0, 50, 100 and 150 ppb O 3 ) in laboratory growth chambers during two separate experiments (autumn and summer) for 4 and 6 weeks, respectively. Ozone effects on Sphagnum mosses and the fluxes of carbon dioxide and methane were evaluated. In both experiments, the three Sphagnum species studied showed only a few significant responses to ozone. In the autumn experiment, membrane permeability of S. angustifolium, measured as conductivity and magnesium leakage, was significantly higher under ozone fumigation (P=0.005 and 2 exchange during the 6-week-long summer experiment, but dark ecosystem respiration was transiently increased by ozone concentration of 100 ppb after 14 days of exposure (P<0.05). Fumigation with 100 ppb of ozone, however, more than doubled (P<0.05) methane emission from the peatland monoliths. Our results suggest that increasing tropospheric ozone concentration may cause substantial changes in the carbon gas cycling of boreal peatlands, even though these changes are not closely associated with the changes in Sphagnum vegetation

  16. Spatio-temporal trends of nitrogen deposition and climate effects on Sphagnum productivity in European peatlands.

    Science.gov (United States)

    Granath, Gustaf; Limpens, Juul; Posch, Maximilian; Mücher, Sander; de Vries, Wim

    2014-04-01

    To quantify potential nitrogen (N) deposition impacts on peatland carbon (C) uptake, we explored temporal and spatial trends in N deposition and climate impacts on the production of the key peat forming functional group (Sphagnum mosses) across European peatlands for the period 1900-2050. Using a modelling approach we estimated that between 1900 and 1950 N deposition impacts remained limited irrespective of geographical position. Between 1950 and 2000 N deposition depressed production between 0 and 25% relative to 1900, particularly in temperate regions. Future scenarios indicate this trend will continue and become more pronounced with climate warming. At the European scale, the consequences for Sphagnum net C-uptake remained small relative to 1900 due to the low peatland cover in high-N areas. The predicted impacts of likely changes in N deposition on Sphagnum productivity appeared to be less than those of climate. Nevertheless, current critical loads for peatlands are likely to hold under a future climate. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Radiocarbon dating of Sphagnum cellulose from Mohos peat bog, East Carpathians

    Science.gov (United States)

    Hubay, Katalin; Braun, Mihály; Harangi, Sándor; Palcsu, László; Túri, Marianna; Rinyu, László; Molnár, Mihály

    2015-04-01

    This work focuses on building a high-resolution age-depth model for quantitative paleoclimate study from the Mohos peat bog, East Carpathians. Peats are important archives for Quaternary science, because they preserve environmental changes. To study the chronology of peat profiles the key is in the precise coring and reliable dating. However, many studies dealing with coring and radiocarbon dating of peat deposits they often shown problems with the proper methods and material. With our novel coring technique we reached undisturbed and uncompressed peat cores from the Mohos bog. A 10 meter deep peat profile was drilled in 2012 using a modified technique of a piston corer. The core presents a continuous peat profile from the last 11.500 cal. yr BP. The chronology was based on AMS radiocarbon analyses of the separated Sphagnum samples from different depths of the profile. The peat samples were wet sieved (40-280 μm) to avoid contamination by rootlets. Dry Sphagnum samples for AMS dating were prepared using the classical acid-base-acid (ABA) method completed with an oxidative bleaching step to get clean cellulose. Sphagnum cellulose samples were converted to CO2 and later graphite and measured by EnvironMICADAS accelerator mass spectrometry (AMS) in Hertelendi Laboratory (Debrecen, Hungary). Fine peat accumulation rate changes (sections with lowest accumulation values) were observed along the profile. Based on the chronology in further studies we want to focus special intervals to investigate environmental changes in the Holocene. Key words: peat, radiocarbon, cellulose

  18. Bacterial Abundance and Activity across Sites within Two Northern Wisconsin Sphagnum Bogs.

    Science.gov (United States)

    Fisher; Graham; Graham

    1998-11-01

    Abstract Bacterial abundance, temperature, pH, and dissolved organic carbon (DOC) concentration were compared across surface sites within and between two northern Wisconsin Sphagnum peatlands over the summer seasons in 1995 and 1996. Sites of interest were the Sphagnum mat surface, the water-filled moat (lagg) at the bog margin, and the bog lake littoral zone. Significant differences in both bacterial populations and water chemistry were observed between sites. pH was highest in the lake and lowest in the mat at both bogs; the opposite was true for DOC. Large populations of bacteria were present in surface interstitial water from the mat; abundance in this site was consistently higher than in the moat or lake. Bacterial abundance also increased across sites of increasing DOC concentration and declining pH. Bacterial activities (rates of [3H]leucine incorporation) and growth in dilution cultures (with grazers removed) were also assessed in lake, moat, and mat sites. Results using these measures generally supported the trends observed in abundance, although high rates of [3H]leucine incorporation were recorded in the moat at one of the bogs. Our results indicate that bacterial populations in Sphagnum peatlands are not adversely affected by acidity, and that DOC may be more important than pH in determining bacterial abundance in these environments.

  19. OCORRÊNCIA E CARACTERIZAÇÃO DO AMIDO RESISTENTE EM AMIDOS DE MILHO E DE BANANA

    Directory of Open Access Journals (Sweden)

    Teixeira Maria A.V.

    1998-01-01

    Full Text Available No presente trabalho foi estudada a ocorrência de Amido Resistente (AR em amidos de milho e de banana (naturalmente resistente e investigado o efeito das variáveis: umidade de condicionamento, tempo e temperatura de armazenamento dos géis, na formação do AR em amido normal de milho; além das características físico-químicas e a estrutura fina do AR de milho e de banana. Foi observado que o teor de AR em amidos de milho e banana (2,5% e 49,61%, respectivamente parece não estar relacionada com a composição química do grânulo. O amido de banana apresentou grânulos com certo poliformismo, padrão de raio-x tipo B, além de uma fração linear de DP 34 resistente à b-amilólise. A estrutura cristalina que mantém o grânulo do amido de banana coeso, por si só, não explicou o alto teor de AR encontrado. O amido de milho normal apresentou formas poliédricas e padrão difração em raio-x tipo A. Não foi observada a fração com DP 34 resistente à b-amilólise, apesar da sua maior coesividade quando comparado ao amido de banana. O tratamento hidrotérmico aplicado no amido normal de milho quase triplicou o teor de AR (7,15% devido à formação de estruturas cristalinas coesas. O AR de milho (7,15% de AR, constituído por fragmentos porosos, apresentou padrão de difração tipo C. A não significância do tempo de armazenamento dos géis na produção do AR e a fração linear com DP 34 resistente à b-amilólise presente nos cromatogramas, sugerem a participação da amilose na formação desta estrutura resistente.

  20. Sphagnum mosses as a microhabitat for invertebrates in acidified lakes and the colour adaptation and substrate preference in Leucorrhinia dubia (Odonata, Anisoptera)

    Energy Technology Data Exchange (ETDEWEB)

    Henrikson, B.-I. (Dept. of Zoology, Sect. of Animal Ecology, Univ. of Goeteborg, Goeteborg (Sweden))

    1993-01-01

    The increase of peat mosses, Sphagnum spp., in acidified lakes leads to a changed microhabitat structure for benthic invertebrates. The importance of this change was investigated for some benthic invertebrates. Comparisons between quantitative samples of Sphagnum and debris within the acidified Lake Stora Haestevatten, in the Lake Gaardsjoen catchment of SW Sweden, showed significantly higher abundances of Chironomidae, Ceratopogonidae, Odonata, Trichoptera, Cladocera and Argyroneta aquatica (Araneae) in Sphagnum. For chironomidae and Cladocera the differences were tenfold. Special reference was made to the libellulid Leucorrhinia dubia which is common in acid lakes. In a laboratory test, late instar larvae of L. dubia were shown to change colour to correspond to the brown and green colour of Sphagnum. This result was completed with a field test where larvae of L. dubia were significantly more common in Sphagnum of the same colour as the larvae. The ability to change colour may have an adaptive value when coexisting with visual predators. Small larvae were more prevalent in Sphagnum and they also showed a preference for this substrate in the laboratory test. Laboratory tests showed mediumsized larvae preferred Sphagnum. Larvae of L. dubia were more successful as predators on Asellus aquaticus in Sphagnum substrate than in debris in the laboratory test. Laboratory predation tests with notonecta glauca, Corixa dentipes, Acilius sulcatus, Hyphydrus ovatus and L. dubia showed that they could all feed on larvae of L. dubia. The complex habitat structure of Sphagnum is probably the reason for the high abundance of invertebrates since it may serve as both shelter against predation and as foraging sites. it is probably important as a key habitat for young instars of, for example, L. dubia. In lakes with large Sphagnum mats, L. dubia can coexist with fish. The expansion of Sphagnum due to acidification will probably benefit many acid-tolerant invertebrate species. (au)

  1. Nuevos genotipos de arroz resistentes a la Piriculariosis obtenidos por cultivo de anteras

    Directory of Open Access Journals (Sweden)

    Rodolfo I Castro

    2012-01-01

    Full Text Available Título en inglés: New blast resistant rice genotypes obtained by and anthers culture. Resumen: En la Estación Experimental del Arroz Los Palacios, perteneciente al Instituto Nacional de Ciencias Agrícolas de Cuba (INCA, se efectuaron cruzamientos entre cuatro cultivares resistentes a la Piriculariosis y seis de buen comportamiento agronómico y las anteras de las plantas F2 fueron cultivadas in vitro para evaluar la formación de callos en tres medios líquidos: N6-1, N6-m y NL, así como la regeneración de plantas verdes y albinas, en el medio MS. Las dos primeras generaciones de las nuevas líneas obtenidas fueron evaluadas para caracteres agronómicos y la segunda generación, además, para resistencia frente a la  Piriculariosis. Las líneas que combinaron resistencia a la Piriculariosis y buenos caracteres agronómicos fueron evaluadas en condiciones de infección natural, con alta presión del patógeno. La utilización de la técnica del cultivo de anteras mostró alta dependencia del genotipo y el medio de cultivo. Con el medio NL se lograron los valores más altos para la formación de callos. Se obtuvieron nuevos genotipos resistentes a la Piriculariosis y  de alto rendimiento agrícola. Palabras clave: Arroz; Mejoramiento genético; Cultivo in Vitro de anteras Summary: Crosses were made between four blast resistant and six rice varieties of good agronomic performance, at the Los Palacios Rice Research Station of the National Agricultural Sciences Institute of Cuba (INCA and the anthers from F2 plants were in vitro culture using three liquid media: N6-1, N6m, and NL, for callus formation and after plants regenerations using MS medium. The first two generations of breeding lines were evaluated for agronomic characters and the second generations, also, for Blast resistant. The lines that combined resistance to Blast and good agronomic performance were evaluated under high pressure of natural Blast infection conditions. The success

  2. Controle de plantas daninhas na cultura de soja resistente ao glyphosate

    Directory of Open Access Journals (Sweden)

    Núbia Maria Correia

    2010-01-01

    Full Text Available O objetivo da pesquisa foi avaliar o controle de plantas daninhas em área cultivada com soja resistente ao herbicida glyphosate, sem a utilização de práticas complementares de manejo de plantas daninhas. Foram desenvolvidos experimentos, em condições de campo, nos anos agrícolas 2005/2006 e 2006/2007 em Jaboticabal (SP. Foram avaliadas duas cultivares de soja resistentes ao glyphosate (CD 214 RR e M-SOY 8008 RR, oito tratamentos de herbicidas (glyphosate, em aplicação única, nas doses de 0,48; 0,72; 0,96 e 1,20 kg ha-1 de equivalente ácido, associadas ou não a aplicação sequencial na dose de 0,48 kg ha-1, além de duas testemunhas, uma capinada e outra mantida infestada. As cultivares de soja influenciaram na infestação das espécies de plantas daninhas na área. Sem a aplicação de glyphosate, houve o predomínio de X. strumarium na área, desfavorecendo a ocorrência de outras espécies. Quando utilizado glyphosate, independentemente da dose, a infestação contabilizada aos 35 e 40 dias após a primeira aplicação, no primeiro e segundo ano, respectivamente, foi baixa. O controle de plantas daninhas na cultura da soja transgênica é diretamente influenciado pela dose de glyphosate, havendo controle satisfatório com a aplicação única de 0,96 kg ha-1 ou a sequencial de 0,48 + 0,48 kg ha-1 de glyphosate. Em situação de menor infestação (2006/2007, a aplicação única de 0,48 kg ha-1 de glyphosate é suficiente para o controle das plantas daninhas. As cultivares de soja transgênica CD 214 RR e M-SOY 8008 RR influenciam diferencialmente a dinâmica das espécies de plantas daninhas, sendo o controle químico mais efetivo na situação de cultivo de M-SOY 8008 RR, em que houve menor diversidade e desenvolvimento das plantas daninhas.

  3. Light-stress avoidance mechanisms in a Sphagnum-dominated wet coastal Arctic tundra ecosystem in Alaska.

    Science.gov (United States)

    Zona, D; Oechel, Walter C; Richards, James H; Hastings, Steven; Kopetz, Irene; Ikawa, Hiroki; Oberbauer, Steven

    2011-03-01

    The Arctic experiences a high-radiation environment in the summer with 24-hour daylight for more than two months. Damage to plants and ecosystem metabolism can be muted by overcast conditions common in much of the Arctic. However, with climate change, extreme dry years and clearer skies could lead to the risk of increased photoxidation and photoinhibition in Arctic primary producers. Mosses, which often exceed the NPP of vascular plants in Arctic areas, are often understudied. As a result, the effect of specific environmental factors, including light, on these growth forms is poorly understood. Here, we investigated net ecosystem exchange (NEE) at the ecosystem scale, net Sphagnum CO2 exchange (NSE), and photoinhibition to better understand the impact of light on carbon exchange from a moss-dominated coastal tundra ecosystem during the summer season 2006. Sphagnum photosynthesis showed photoinhibition early in the season coupled with low ecosystem NEE. However, later in the season, Sphagnum maintained a significant CO2 uptake, probably for the development of subsurface moss layers protected from strong radiation. We suggest that the compact canopy structure of Sphagnum reduces light penetration to the subsurface layers of the moss mat and thereby protects the active photosynthetic tissues from damage. This stress avoidance mechanism allowed Sphagnum to constitute a significant percentage (up to 60%) of the ecosystem net daytime CO2 uptake at the end of the growing season despite the high levels of radiation experienced.

  4. Elevated atmospheric CO2 and increased nitrogen deposition : effects on C and N metabolism and growth of the peat moss Sphagnum recurvum P. Beauv. var. mucronatum (Russ.) Warnst

    NARCIS (Netherlands)

    van der Heijden, E; Verbeek, S.K.; Kuiper, P.J C

    Sphagnum bogs play an important role when considering the impacts of global change on global carbon and nitrogen cycles. Sphagnum recurvum P. Beauv. var. mucronatum (Russ.) was grown at 360 (ambient) and 700 mu L L-1 (elevated) atmospheric [CO2] in combination with different nitrogen deposition

  5. Haemonchus resistente a lactona macrocíclica em caprinos naturalmente parasitados

    Directory of Open Access Journals (Sweden)

    Mattos Mary Jane Tweedie de

    2004-01-01

    Full Text Available O ivermectin, antiparasitário amplamente utilizado em caprinos jovens, foi avaliado sobre nematódeos gastrintestinais, em todas as fases parasitárias. Doze caprinos jovens, naturalmente parasitados foram utilizados no experimento, sendo um grupo de seis animais medicado com ivermectin, na dose de 200µg.kg-1 v.o. e o outro grupo utilizado como controle. Para a avaliação, utilizou-se o teste de redução na contagem de ovos (FECR, redução de larvas infectantes e carga parasitária. Amostras fecais de caprinos foram coletadas no dia da medicação (dia zero, aos sete e catorze dias. No décimo quarto dia pós-medicação, todos os caprinos foram sacrificados, para a coleta de helmintos e cálculo da carga parasitária total. A redução do número de ovos (FECR e a eficácia sobre adultos foi de 42,10 % e 32,62 %, respectivamente.O gênero Haemonchus representou 100 % da população do grupo medicado e 99,58 % do grupo controle. Estes resultados indicam que os caprinos já estavam parasitados por Haemonchus resistente ao ivermectin.

  6. Environmental controls on δ13C variations of Sphagnum derived n-alkanes in the Dajiuhu peatland, central China

    Science.gov (United States)

    Huang, X.; Xue, J.; Wang, X.; WANG, H.; Meyers, P. A.; Qin, Y.; Gong, L.; Ding, W.

    2012-12-01

    Northern peatlands are one of the very important atmospheric carbon sinks and represent about 30% of the global soil organic carbon (Gorham, 1991). In peatland conditions, high water levels and consequent anoxia make them an important source of methane. A recent study revealed that methanotrophic bacteria growing on stems or in hyaline cells of Sphagnum can provide methane derived carbon for photosynthesis (Raghoebarsing et al., 2005). This interaction has been found to be globally prevalent in peat-moss ecosystems and can contribute up to 30% of carbon for Sphagnum photosynthesis (Kip et al., 2010). Due to the uptake of 13C-depleted methane-derived CO2 and the sensitivity of methane oxidizing bacteria to the surface wetness, the carbon isotopic signatures of Sphagnum derived lipids have the potential to be used as a proxy for the surface wetness in peatlands and hence as paleoclimate archives (Nichols et al., 2009). In this study, we report the δ13C variations of the Sphagnum derived n-C23 alkane in both fresh Sphagnum and surface peat samples in the Dajiuhu peatland, a small fen located in the Shennongjia forestry region, Hubei province, central China. The δ13C23 values of Sphagnum show a negative correlation with the water level, supporting the idea that that the carbon isotope fractionation of Sphagnum is mainly manifested by the diffusion resistance of CO2 in hyaline cells of Sphagnum. However, δ13C23 values of surface peats collected in Sphagnum dominated ecosystems display a positive relation with the water level when the water level is less than 30 cm. Such an inconsistency probably results from the higher potential for methane-oxidizing activity in the lower parts of Sphagnum in fen meadows. When the water level is higher than 30 cm, the influence of symbiotic methanotrophic bacteria on Sphagnum derived n-C23 alkane is weak or nearly absent. These findings provide direct evidence to support the hypothesis that the carbon isotopic signatures of Sphagnum

  7. The effect of temperature on growth and competition between Sphagnum species.

    Science.gov (United States)

    Breeuwer, Angela; Heijmans, Monique M P D; Robroek, Bjorn J M; Berendse, Frank

    2008-05-01

    Peat bogs play a large role in the global sequestration of C, and are often dominated by different Sphagnum species. Therefore, it is crucial to understand how Sphagnum vegetation in peat bogs will respond to global warming. We performed a greenhouse experiment to study the effect of four temperature treatments (11.2, 14.7, 18.0 and 21.4 degrees C) on the growth of four Sphagnum species: S. fuscum and S. balticum from a site in northern Sweden and S. magellanicum and S. cuspidatum from a site in southern Sweden. In addition, three combinations of these species were made to study the effect of temperature on competition. We found that all species increased their height increment and biomass production with an increase in temperature, while bulk densities were lower at higher temperatures. The hollow species S. cuspidatum was the least responsive species, whereas the hummock species S. fuscum increased biomass production 13-fold from the lowest to the highest temperature treatment in monocultures. Nutrient concentrations were higher at higher temperatures, especially N concentrations of S. fuscum and S. balticum increased compared to field values. Competition between S. cuspidatum and S. magellanicum was not influenced by temperature. The mixtures of S. balticum with S. fuscum and S. balticum with S. magellanicum showed that S. balticum was the stronger competitor, but it lost competitive advantage in the highest temperature treatment. These findings suggest that species abundances will shift in response to global warming, particularly at northern sites where hollow species will lose competitive strength relative to hummock species and southern species.

  8. Effect of N deposition on tree amino acid concentrations in two Sphagnum species

    Energy Technology Data Exchange (ETDEWEB)

    Karsisto, M; Kitunen, V [Finnish Forest Research Inst., Vantaa (Finland). Vantaa Research Centre; Jauhiainen, J [Joensuu Univ. (Finland). Dept. of Biology; Vasander, H [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1997-12-31

    Nitrogen saturation of ecosystems occurs when the availability of nitrogen is not a growth limiting factor. This situation can be reached through fertilisation or by nitrogen deposition. Prolonged nitrogen saturation may overload the ecosystem and cause changes in the vigour and eventually in the composition of plant communities. But before this stage is reached, certain changes in nitrogen metabolism occur. These changes can be used as an early warning of nitrogen overload to ecosystems. A change in the amino acid pool of plants has been used as an indication of various kind of stress, including, temperature, nutrient imbalance, shading, drought or excess water. It has been postulated that such stresses have an effect on protein synthesis but not on the nitrogen uptake of plants. The result is an increase in the concentration of NH{sub 4}{sup +} ions in plant cells, which may have toxic effects to the plant and the processes that assimilate the free NH{sub 4}{sup +} ions. One of such process is the synthesis of amino acids, especially those containing a significant proportion of nitrogen, e.g. arginine, glutamine and asparagine. This study about the quantification of amino acids in two species of Sphagnum mosses is part of a larger study, the aim of which is to clarify how a number of Sphagnum species will cope with climatic change and nitrogen deposition. Sphagna are the most important members of the peat forming communities in the boreal zone. Sphagnum communities are formed by species specialised to grow in conditions of low nutrient availability, mainly provided via deposition. The present structure and composition of mire communities may be endangered due to elevated levels of nitrogen deposition that have persisted over the last few decades. (20 refs.)

  9. Effects of shading on relative competitive advantage of three species of Sphagnum

    Directory of Open Access Journals (Sweden)

    J.Z. Ma

    2015-06-01

    Full Text Available (1 Sphagnum is an important genus of bryophytes holding 10–15 % of the terrestrial carbon stock. With climate change a drier surface may increase the abundance of vascular plants on peatlands, so shading of Sphagnum may increase. Here we describe growth cabinet experiments to reveal the effects of shading on interactions among mixtures of three species: S. capillifolium, S. palustre (hummock species, and S. fallax (a hollow species. We measured the six traits: growth in length, growth as increase in dry mass, side-shoot production, nitrogen and carbon proportion of the capitulum dry mass, and C:N ratio in the capitulum. (2 Shading had no effect on biomass production or side-shoot production but increased height increment in all three species. It also increased the C and N proportions of total dry mass but decreased C:N ratio in the capitula. (3 Neighbours of a different species reduced biomass and side-shoot production in the two hummock species but had no effect on the hollow species. (4 All three species showed interaction between shading and neighbour in two or more plant traits. S. fallax showed competitive advantage over S. palustre in no-shading treatments and over S. capillifolium in moderate shading treatments. In addition, under deep shading, S. fallax showed a competitive advantage over both hummock species. A clear competitive hierarchy S. fallax>S. capillifolium>S. palustre emerged which was consistent with the hierarchy of side-shoot production. (5 The results suggest that all the species appear to tolerate deep shade (for a few months at least. In a shaded environment, especially under deeply shaded conditions, S. fallax retains its dominance in hollow habitats (if water availability is guaranteed by virtue of its advantage in side-shoot production. (6 If shading increases then the abundance of different Sphagnum species is likely to change.

  10. Spatial Genetic Structure of the Abundant and Widespread Peatmoss Sphagnum magellanicum Brid.

    Directory of Open Access Journals (Sweden)

    Magni Olsen Kyrkjeeide

    Full Text Available Spore-producing organisms have small dispersal units enabling them to become widespread across continents. However, barriers to gene flow and cryptic speciation may exist. The common, haploid peatmoss Sphagnum magellanicum occurs in both the Northern and Southern hemisphere, and is commonly used as a model in studies of peatland ecology and peatmoss physiology. Even though it will likely act as a rich source in functional genomics studies in years to come, surprisingly little is known about levels of genetic variability and structuring in this species. Here, we assess for the first time how genetic variation in S. magellanicum is spatially structured across its full distribution range (Northern Hemisphere and South America. The morphologically similar species S. alaskense was included for comparison. In total, 195 plants were genotyped at 15 microsatellite loci. Sequences from two plastid loci (trnG and trnL were obtained from 30 samples. Our results show that S. alaskense and almost all plants of S. magellanicum in the northern Pacific area are diploids and share the same gene pool. Haploid plants occur in South America, Europe, eastern North America, western North America, and southern Asia, and five genetically differentiated groups with different distribution ranges were found. Our results indicate that S. magellanicum consists of several distinct genetic groups, seemingly with little or no gene flow among them. Noteworthy, the geographical separation of diploids and haploids is strikingly similar to patterns found within other haploid Sphagnum species spanning the Northern Hemisphere. Our results confirm a genetic division between the Beringian and the Atlantic that seems to be a general pattern in Sphagnum taxa. The pattern of strong genetic population structuring throughout the distribution range of morphologically similar plants need to be considered in future functional genomic studies of S. magellanicum.

  11. Photosynthetic performance in Sphagnum transplanted along a latitudinal nitrogen deposition gradient.

    Science.gov (United States)

    Granath, Gustaf; Strengbom, Joachim; Breeuwer, Angela; Heijmans, Monique M P D; Berendse, Frank; Rydin, Håkan

    2009-04-01

    Increased N deposition in Europe has affected mire ecosystems. However, knowledge on the physiological responses is poor. We measured photosynthetic responses to increasing N deposition in two peatmoss species (Sphagnum balticum and Sphagnum fuscum) from a 3-year, north-south transplant experiment in northern Europe, covering a latitudinal N deposition gradient ranging from 0.28 g N m(-2) year(-1) in the north, to 1.49 g N m(-2) year(-1) in the south. The maximum photosynthetic rate (NP(max)) increased southwards, and was mainly explained by tissue N concentration, secondly by allocation of N to the photosynthesis, and to a lesser degree by modified photosystem II activity (variable fluorescence/maximum fluorescence yield). Although climatic factors may have contributed, these results were most likely attributable to an increase in N deposition southwards. For S. fuscum, photosynthetic rate continued to increase up to a deposition level of 1.49 g N m(-2) year(-1), but for S. balticum it seemed to level out at 1.14 g N m(-2) year(-1). The results for S. balticum suggested that transplants from different origin (with low or intermediate N deposition) respond differently to high N deposition. This indicates that Sphagnum species may be able to adapt or physiologically adjust to high N deposition. Our results also suggest that S. balticum might be more sensitive to N deposition than S. fuscum. Surprisingly, NP(max) was not (S. balticum), or only weakly (S. fuscum) correlated with biomass production, indicating that production is to a great extent is governed by factors other than the photosynthetic capacity.

  12. Unsaturated hydraulic properties of Sphagnum moss and peat reveal trimodal pore-size distributions

    Science.gov (United States)

    Weber, Tobias K. D.; Iden, Sascha C.; Durner, Wolfgang

    2017-01-01

    In ombrotrophic peatlands, the moisture content of the vadose zone (acrotelm) controls oxygen diffusion rates, redox state, and the turnover of organic matter. Whether peatlands act as sinks or sources of atmospheric carbon thus relies on variably saturated flow processes. The Richards equation is the standard model for water flow in soils, but it is not clear whether it can be applied to simulate water flow in live Sphagnum moss. Transient laboratory evaporation experiments were conducted to observe evaporative water fluxes in the acrotelm, containing living Sphagnum moss, and a deeper layer containing decomposed moss peat. The experimental data were evaluated by inverse modeling using the Richards equation as process model for variably-saturated flow. It was tested whether water fluxes and time series of measured pressure heads during evaporation could be simulated. The results showed that the measurements could be matched very well providing the hydraulic properties are represented by a suitable model. For this, a trimodal parametrization of the underlying pore-size distribution was necessary which reflects three distinct pore systems of the Sphagnum constituted by inter-, intra-, and inner-plant water. While the traditional van Genuchten-Mualem model led to great discrepancies, the physically more comprehensive Peters-Durner-Iden model which accounts for capillary and noncapillary flow, led to a more consistent description of the observations. We conclude that the Richards equation is a valid process description for variably saturated moisture fluxes over a wide pressure range in peatlands supporting the conceptualization of the live moss as part of the vadose zone.

  13. Spatial Genetic Structure of the Abundant and Widespread Peatmoss Sphagnum magellanicum Brid.

    Science.gov (United States)

    Kyrkjeeide, Magni Olsen; Hassel, Kristian; Flatberg, Kjell Ivar; Shaw, A Jonathan; Yousefi, Narjes; Stenøien, Hans K

    2016-01-01

    Spore-producing organisms have small dispersal units enabling them to become widespread across continents. However, barriers to gene flow and cryptic speciation may exist. The common, haploid peatmoss Sphagnum magellanicum occurs in both the Northern and Southern hemisphere, and is commonly used as a model in studies of peatland ecology and peatmoss physiology. Even though it will likely act as a rich source in functional genomics studies in years to come, surprisingly little is known about levels of genetic variability and structuring in this species. Here, we assess for the first time how genetic variation in S. magellanicum is spatially structured across its full distribution range (Northern Hemisphere and South America). The morphologically similar species S. alaskense was included for comparison. In total, 195 plants were genotyped at 15 microsatellite loci. Sequences from two plastid loci (trnG and trnL) were obtained from 30 samples. Our results show that S. alaskense and almost all plants of S. magellanicum in the northern Pacific area are diploids and share the same gene pool. Haploid plants occur in South America, Europe, eastern North America, western North America, and southern Asia, and five genetically differentiated groups with different distribution ranges were found. Our results indicate that S. magellanicum consists of several distinct genetic groups, seemingly with little or no gene flow among them. Noteworthy, the geographical separation of diploids and haploids is strikingly similar to patterns found within other haploid Sphagnum species spanning the Northern Hemisphere. Our results confirm a genetic division between the Beringian and the Atlantic that seems to be a general pattern in Sphagnum taxa. The pattern of strong genetic population structuring throughout the distribution range of morphologically similar plants need to be considered in future functional genomic studies of S. magellanicum.

  14. The effect of temperature on growth and competition between Sphagnum species

    Science.gov (United States)

    Heijmans, Monique M. P. D.; Robroek, Bjorn J. M.; Berendse, Frank

    2008-01-01

    Peat bogs play a large role in the global sequestration of C, and are often dominated by different Sphagnum species. Therefore, it is crucial to understand how Sphagnum vegetation in peat bogs will respond to global warming. We performed a greenhouse experiment to study the effect of four temperature treatments (11.2, 14.7, 18.0 and 21.4°C) on the growth of four Sphagnum species: S. fuscum and S. balticum from a site in northern Sweden and S. magellanicum and S. cuspidatum from a site in southern Sweden. In addition, three combinations of these species were made to study the effect of temperature on competition. We found that all species increased their height increment and biomass production with an increase in temperature, while bulk densities were lower at higher temperatures. The hollow species S. cuspidatum was the least responsive species, whereas the hummock species S. fuscum increased biomass production 13-fold from the lowest to the highest temperature treatment in monocultures. Nutrient concentrations were higher at higher temperatures, especially N concentrations of S. fuscum and S. balticum increased compared to field values. Competition between S. cuspidatum and S. magellanicum was not influenced by temperature. The mixtures of S. balticum with S. fuscum and S. balticum with S. magellanicum showed that S. balticum was the stronger competitor, but it lost competitive advantage in the highest temperature treatment. These findings suggest that species abundances will shift in response to global warming, particularly at northern sites where hollow species will lose competitive strength relative to hummock species and southern species. PMID:18283501

  15. Effect of N deposition on tree amino acid concentrations in two Sphagnum species

    Energy Technology Data Exchange (ETDEWEB)

    Karsisto, M.; Kitunen, V. [Finnish Forest Research Inst., Vantaa (Finland). Vantaa Research Centre; Jauhiainen, J. [Joensuu Univ. (Finland). Dept. of Biology; Vasander, H. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    Nitrogen saturation of ecosystems occurs when the availability of nitrogen is not a growth limiting factor. This situation can be reached through fertilisation or by nitrogen deposition. Prolonged nitrogen saturation may overload the ecosystem and cause changes in the vigour and eventually in the composition of plant communities. But before this stage is reached, certain changes in nitrogen metabolism occur. These changes can be used as an early warning of nitrogen overload to ecosystems. A change in the amino acid pool of plants has been used as an indication of various kind of stress, including, temperature, nutrient imbalance, shading, drought or excess water. It has been postulated that such stresses have an effect on protein synthesis but not on the nitrogen uptake of plants. The result is an increase in the concentration of NH{sub 4}{sup +} ions in plant cells, which may have toxic effects to the plant and the processes that assimilate the free NH{sub 4}{sup +} ions. One of such process is the synthesis of amino acids, especially those containing a significant proportion of nitrogen, e.g. arginine, glutamine and asparagine. This study about the quantification of amino acids in two species of Sphagnum mosses is part of a larger study, the aim of which is to clarify how a number of Sphagnum species will cope with climatic change and nitrogen deposition. Sphagna are the most important members of the peat forming communities in the boreal zone. Sphagnum communities are formed by species specialised to grow in conditions of low nutrient availability, mainly provided via deposition. The present structure and composition of mire communities may be endangered due to elevated levels of nitrogen deposition that have persisted over the last few decades. (20 refs.)

  16. Plant diversity affects GHG fluxes in an ecological engineering experiment in a disturbed Sphagnum peatland (La Guette, France)

    Science.gov (United States)

    Gogo, Sébastien; Laggoun-Défarge, Fatima; Leroy, Fabien; Guimbaud, Christophe; Bernard-Jannin, Léonard

    2017-04-01

    Many Sphagnum peatlands are experiencing vegetation change caused mainly by hydrological disturbances. In the context of these direct and indirect modifications, greenhouse gases (GHG) fluxes are affected by peat oxygenation, changes in litter composition (and thus decomposition) and rhizospheric processes (such as root exudates). This could lead a C sink system to switch to a source. To restore peatland functioning, ecological engineering works can be undertaken. Our study site, La Guette peatland (central France) is invaded by Molinia caerulea because a drain at the output decreased the water table depth. It was shown that it functioned as a source of C. In 2014, hydrological works were undertaken: 8 dams were installed, ditches were dug perpendicular to the water flow and back-filled with a mixture of shales and bentonite. In addition, a biodiversity experiment with 2 identical experimental stations was implemented: "downstream", close to the hydraulic works (relatively wet), "upstream", (relatively dry), with types of 3 vegetation plot (2m x 2m, n=4): 1) "control": intact vegetation (Molinia caerulea, Erica tetralix), 2) "bare" peat: vegetation and 5cm of peat were removed, 3) "Sphagnum": bare peat+Sphagnum. Our study aims to assess the effect of the vegetation treatment on the GHG fluxes. CO2 (ecosystem respiration or ER, Gross Primary Production or GPP, and Net Ecosystem Exchange) and CH4 fluxes (manual accumulation chamber), air and soil temperature, water table level, soil moisture were measured. After 18 months, half of the surface of "bare" and "Sphagnum" plots were covered by vegetation (Eriophorum angustifolium, Rynchospora alba, Trichophorum cespitosum). With time, as succession unfolds in these 2 types of station, ER and GPP increased. The sensitivity of ER to temperature increased sharply in "bare" and "Sphagnum" plots with years and became higher than the sensitivity in "control" plots. GPP increased with the total vegetation percentage cover

  17. Mechanochemical treatment of amorphous carbon from brown sphagnum moss for the preparation of carbon nanotubes

    International Nuclear Information System (INIS)

    Onishchenko, D.V.

    2013-01-01

    Under consideration is the mechanism of multiwalled nanotubes formation during mechanical activation of amorphous carbon synthesized by pyrolysis of sphagnum moss. The formation of nanotubes has been shown to take place in the array of carbon particles. A complex study of the sorption characteristics of carbon nanotubes has been carried out. The dependence of the sorption capacity of carbon nanotubes on their storage time, as well as the effect of the process parameters of nanotubes formation on their ability for oxidative modification, is represented. (authors)

  18. The response of vegetation structure to active warming and precipitation reduction of the Sphagnum peatland

    Science.gov (United States)

    Łuców, Dominika; Basińska, Anna; Chojnicki, Bogdan; Gąbka, Maciej; Józefczyk, Damian; Juszczak, Radosław; Leśny, Jacek; Olejnik, Janusz; Reczuga, Monika; Samson, Mateusz; Silvennoinen, Hanna; Stróżecki, Marcin; Urbaniak, Marek; Zielińska, Małgorzata; Lamentowicz, Mariusz

    2017-04-01

    The recent climate change (e.g. increased temperature and decreased precipitation) is expected to affect biodiversity and vegetation structure of the European peatlands, as well as carbon fluxes. Our experimental study carried out in Western Poland, tests the hypothesis that the increased temperature, in particular in combination with rainfall reduction affects vegetation structure of the Sphagnum peatland, through changes in moss and vascular plants abundance. The innovative climate manipulation system was installed on the Rzecin peatland in 2014. The field site consists of four blocks: "drought" "warming and drought" "warming" and "control". The air and peat temperatures were increased in 2015 and 2016 by about 0.2 oC and 1.0 oC, respectively, using infrared radiators. Precipitation was reduced by automatic curtain operated only during the nights by about 37 % in both years. Data resulting from the analyses of digital pictures as well as Point Intercept method were used to identify changes in vegetation structure as a response to warming and drought. We observed increase in abundance of vascular plant and decrease in abundance of mosses during the very dry 2015 vegetation season. It appeared that Carex spp. (C. limosa and C. rostrata) abundance responded positively to warming, while Sphagnum spp. (S. angustifolium and S. teres) responded negatively. The "warming" block was characterized by an increase in abundance of Carex spp. by 8.3 % to 16.7 % and decreased abundance of Sphagnum spp. from 25 % to 19.4 %, whereas in the block of "warming and drought" 11.4 % to by 18.3 and 38 % to 26.9 %, respectively in the August 2015. However, we observed decrease in Sphagnum spp. abundance in the treatment with rainfall reduction in wetter 2016, and their increase in the control. Our results show how considerable changes in vegetation structure can be expected under the stress of warming and modified rainfall conditions, even after a short-term manipulation. However, it is

  19. Infeção por staphylococcus aureus meticilina-resistente da comunidade em Portugal

    Directory of Open Access Journals (Sweden)

    R. Nazareth

    2012-01-01

    Full Text Available Resumo: Recentemente assistiu-se à emergência de infeções na comunidade por Staphylococcus aureus meticilina-resistente (MRSA em indivíduos sem fatores de risco. O MRSA associado à comunidade (CA-MRSA parece ser mais virulento, causando desde infeções superficiais da pele e tecidos moles até fasceíte necrosante e, raramente, pneumonia.O CA-MRSA foi inicialmente identificado na Austrália no início da década de 80 e, após cerca de duas décadas, surgiu nos EUA e em vários países da Europa, Ásia e América do Sul. Não existe informação disponível acerca da prevalência em Portugal.Os autores reportam o primeiro caso de infeção por CA-MRSA em Portugal, num adulto jovem com pneumonia necrotizante grave complicada por empiema bilateral e insuficiência respiratória. Abstract: Methicillin-resistant Staphylococcus aureus (MRSA has recently emerged as a cause of community-acquired infections among individuals without risk factors. Community-associated MRSA (CA-MRSA appears to be more virulent, causing superficial mild skin and soft tissue infections to severe necrotizing fasciitis, and in rare cases, pneumonia.Community-associated MRSA was first reported in Australia in the early 80s, after almost two decades in the USA, and then in several countries in Europe, Asia and South America. No data exists in Portugal.We report the first case of CA-MRSA infection in Portugal, in a young adult with severe necrotizing pneumonia, complicated with bilateral empyema and respiratory failure. Palavras-chave: comunidade associada, MRSA, Staphylococcus aureus, pneumonia necrosante, empiema, Keywords: Community-associated, MRSA, Staphylococcus aureus, Necrotizing pneumonia, Empyema

  20. Amido resistente em diversas fontes não convencionais de amido

    Directory of Open Access Journals (Sweden)

    C. Fontinha

    2016-02-01

    Full Text Available Amido resistente (AR é aquele que não é digerido no intestino delgado, conduzindo a efeitos benéficos para a saúde, tal como a fibra dietética faz. Procedeu-se à determinação do AR em farinhas e amidos extraídos de duas variedades de castanha (Castanea sativa Mill, Longal e Martainha, da bolota de azinheira (Quercus rotundifolia e da glande do sobreiro (Quercus suber. As farinhas foram obtidas por moenda dos frutos após secagem a diferentes temperaturas, 40º C, 50º C, 60ºC e 70ºC. Posteriormente, procedeu-se ao isolamento dos amidos das farinhas, através da aplicação de dois métodos de extracção: um físico-químico e outro enzimático. Verificou-se que os teores de AR mais elevados foram os apresentados pelas farinhas dos frutos secos a 60ºC, sendo de 46,8%, 36,5%, 39,9% e 43,9%, respectivamente para as castanhas das variedades Longal e Martainha, para a bolota e para a glande. O método de extracção que apresentou valores mais elevados de AR para os amidos extraídos dos diferentes materiais foi o método físico-químico. Tudo indica que a secagem dos frutos a 60ºC e a aplicação do método de extracção do amido pelo processo físico-químico nas farinhas dos frutos secos a esta temperatura são aqueles que melhor preservam a estrutura dos amidos.

  1. Fagoterapia frente a infecciones por Staphylococcus aureus meticilino resistente en ratones

    Directory of Open Access Journals (Sweden)

    Jesús H Tamariz

    Full Text Available Objetivos: Evaluar la actividad de los bacteriófagos frente a infecciones localizadas y sistémicas producidas por Staphylococcus aureus resistente a meticilina (MRSA Materiales y métodos. Se realizó un estudio de tipo experimental en 45 ratones de la cepa Balb/c divididos en nueve grupos de cinco individuos. Se aislaron diez bacteriófagos nativos a partir de muestras clínicas y efluentes hospitalarios, se evaluó su capacidad lítica y su espectro de actividad, en base a lo cual se seleccionaron seis fagos para los ensayos de fagoterapia. Adicionalmente, se empleó un bacteriófago de origen comercial. La fagoterapia fue evaluada mediante profilaxis y terapia de infecciones localizadas y sistémicas causadas por la inoculación de MRSA por vía subcutánea y endovenosa respectivamente. Se probó la efectividad de tres esquemas terapéuticos: monoterapia, cóctel de fagos en múltiples dosis y de cóctel de fagos en una sola dosis. También se comparó la actividad terapéutica de los fagos frente a vancomicina y clindamicina. Resultados. El cóctel de fagos y la terapia a diversas dosis fueron efectivos para prevenir y controlar infecciones localizadas por MRSA, su actividad fue similar a la de vancomicina y clindamicina. La dosis única del cóctel de fagos no logró controlar la infección localizada; asimismo, la fagoterapia no resultó efectiva en infecciones sistémicas. Conclusiones. La fagoterapia se proyecta como una alternativa viable frente a infecciones causadas por MRSA. Se requieren estudios que evalúen aspectos relacionados con la inocuidad de los fagos frente al paciente

  2. Caracterización fisicoquímica de almidones de tubérculos cultivados en Yucatán, México Caracterização físico-química de amidos de tubérculos cultivados em Yucatán, México

    Directory of Open Access Journals (Sweden)

    Marilyn Hernández-Medina

    2008-09-01

    Full Text Available Se realizó la evaluación de las propiedades fisicoquímicas y funcionales de almidones de tubérculos: makal (Xanthosoma yucatanensis, camote (Ipomea batata, yuca (Manihot esculenta Crantz y sagú (Marantha arundinacea. El tamaño promedio de los gránulos de almidón varió de 10,6 a 16,5 µm. La amilosa fue de 23,6, 19,6, 17,0 y 22,7%, para el makal, camote, yuca y sagú. Las temperaturas de gelatinización fueron de 78,4, 61,3, 65,2 y 74,9 °C, respectivamente. El almidón de yuca fue el que presentó mayor poder de hinchamiento y solubilidad. La viscosidad máxima fue para el almidón de yuca. El almidón de camote presentó la mayor claridad de gel (51,8% y el de makal, la menor (10,9%. El almidón de yuca fue el más elástico (36,2%. Los almidones de makal y de sagú pueden ser utilizados en productos que requieren altas temperaturas de procesamiento. Los almidones de camote y de yuca pueden ser incluidos en sistemas alimenticios como espesantes, estabilizantes y gelificantes en alimentos refrigerados y congelados.Foram avaliadas as propriedades físico-químicas e funcionais de amidos dos seguintes tubérculos: makal (Xanthosoma yucatanensis, batata-doce (Ipomea batata, mandioca (Manihot esculenta Crantz e araruta (Marantha arundinacea. O tamanho médio dos grânulos de amido variou de 10,6 a 16,5 µm. A amilose foi de 23,6, 19,6, 17,0 e 22,7%, para makal, batata-doce, mandioca e araruta. As temperaturas de gelatinização foram de 78,4, 61,3, 65,2 e 74,9 °C, respectivamente. O amido de mandioca foi o que apresentou maior poder de inchamento e solubilidade. A viscosidade máxima foi para o amido de mandioca. O amido de batata-doce apresentou a maior claridade de gel (51,8% e o amido de makal, a menor (10,9%. O amido de mandioca foi o mais elástico (36,2%. Os amidos de makal e de araruta podem ser utilizados em produtos que requerem altas temperaturas de processamento. Os amidos de batata-doce e de mandioca podem ser incluídos em

  3. Effects of volume change on the unsaturated hydraulic conductivity of Sphagnum moss

    Science.gov (United States)

    Golubev, V.; Whittington, P.

    2018-04-01

    Due to the non-vascular nature of Sphagnum mosses, the capitula (growing surface) of the moss must rely solely on capillary action to receive water from beneath. Moss subsides and swells in accordance with water table levels, an effect called "mire-breathing", which has been thought to be a self-preservation mechanism, although no systematic studies have been done to demonstrate exactly how volume change affects hydrophysical properties of moss. In this study, the unsaturated hydraulic conductivity (Kunsat) and water content of two different species of Sphagnum moss were measured at different compression rates, up to the maximum of 77%. The findings show that the Kunsat increases by up to an order of magnitude (10×) with compression up to a certain bulk density of the moss, after which higher levels of compression result in lowered unsaturated hydraulic conductivity. This was coupled with an increase in soil water retention with increased compression. The increase of the Kunsat with compression suggests that the mire-breathing effect should be considered a self-preservation mechanism to provide sufficient amount of water to growing moss in times of low water availability.

  4. Seasonal changes in Sphagnum peatland testate amoeba communities along a hydrological gradient.

    Science.gov (United States)

    Marcisz, Katarzyna; Lamentowicz, Lukasz; Słowińska, Sandra; Słowiński, Michał; Muszak, Witold; Lamentowicz, Mariusz

    2014-10-01

    Testate amoebae are an abundant and functionally important group of protists in peatlands, but little is known about the seasonal patterns of their communities. We investigated the relationships between testate amoeba diversity and community structure and water table depth and light conditions (shading vs. insolation) in a Sphagnum peatland in Northern Poland (Linje mire) in spring and summer 2010. We monitored the water table at five sites across the peatland and collected Sphagnum samples in lawn and hummock micro-sites around each piezometer, in spring (3 May) and mid-summer (6 August) 2010. Water table differed significantly between micro-sites and seasons (Kruskal-Wallis test, p=0.001). The community structure of testate amoebae differed significantly between spring and summer in both hummock and lawn micro-sites. We recorded a small, but significant drop in Shannon diversity, between spring and summer (1.76 vs. 1.72). Strongest correlations were found between testate amoeba communities and water table lowering and light conditions. The relative abundance of mixotrophic species Hyalosphenia papilio, Archerella flavum and of Euglypha ciliata was higher in the summer. Copyright © 2014 Elsevier GmbH. All rights reserved.

  5. Sphagnum peatland development at their southern climatic range in West Siberia: trends and peat accumulation patterns

    International Nuclear Information System (INIS)

    Peregon, Anna; Uchida, Masao; Shibata, Yasuyuki

    2007-01-01

    A region of western Siberia is vulnerable to the predicted climatic change which may induce an important modification to the carbon balance in wetland ecosystems. This study focuses on the evaluation of both the long-term and contemporary trends of peat (carbon) accumulation and its patterns at the southern climatic range of Sphagnum peatlands in western Siberia. Visible and physical features of peat and detailed reconstructions of successional change (or sediment stratigraphies) were analysed at two types of forest-peatland ecotones, which are situated close to each other but differ by topography and composition of their plant communities. Our results suggest that Siberian peatlands exhibit a general trend towards being a carbon sink rather than a source even at or near the southern limit of their distribution. Furthermore, two types of peat accumulation were detected in the study area, namely persistent and intermittent. As opposed to persistent peat accumulation, the intermittent one is characterized by the recurrent degradation of the upper peat layers at the marginal parts of raised bogs. Persistent peat accumulation is the case for the majority of Sphagnum peatlands under current climatic conditions. It might be assumed that more peat will accumulate under the 'increased precipitation' scenarios of global warming, although intermittent peat accumulation could result in the eventual drying that may change peatlands from carbon sinks to carbon sources

  6. North American origin and recent European establishments of the amphi-Atlantic peat moss Sphagnum angermanicum.

    Science.gov (United States)

    Stenøien, Hans K; Shaw, A Jonathan; Shaw, Blanka; Hassel, Kristian; Gunnarsson, Urban

    2011-04-01

    Genetic and morphological similarity between populations separated by large distances may be caused by frequent long-distance dispersal or retained ancestral polymorphism. The frequent lack of differentiation between disjunct conspecific moss populations on different continents has traditionally been explained by the latter model, and has been cited as evidence that many or most moss species are extremely ancient and slowly diverging. We have studied intercontinental differentiation in the amphi-Atlantic peat moss Sphagnum angermanicum using 23 microsatellite markers. Two major genetic clusters are found, both of which occur throughout the distributional range. Patterns of genetic structuring and overall migration patterns suggest that the species probably originated in North America, and seems to have been established twice in Northern Europe during the past 40,000 years. We conclude that similarity between S. angermanicum populations on different continents is not the result of ancient vicariance and subsequent stasis. Rather, the observed pattern can be explained by multiple long-distance dispersal over limited evolutionary time. The genetic similarity can also partly be explained by incomplete lineage sorting, but this appears to be caused by the short time since separation. Our study adds to a growing body of evidence suggesting that Sphagnum, constituting a significant part of northern hemisphere biodiversity, may be more evolutionary dynamic than previously assumed. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  7. Effect of light Sphagnum peat on odour formation in the early stages of biowaste composting.

    Science.gov (United States)

    Kurola, Jukka M; Arnold, Mona; Kontro, Merja H; Talves, Matti; Romantschuk, Martin

    2010-05-01

    In the present study, we investigated the effects of two bulking materials, Sphagnum peat and pine wood chips, on the early stages of biowaste composting in two pilot-scale processes. Emphasis was placed on studying the formation conditions of malodorous compost gases in the initial phases of the processes. The results showed that gas emission leaving an open windrow and a closed drum composting system contained elevated concentrations of fermentative microbial metabolites when acid Sphagnum peat (pH 3.2) was used as a bulking material. Moreover, the gas emission of the peat amended drum composter contained a high concentration of odour (up to 450,000oum(-3) of air). The highest odour values in the outlet gas of peat amended composts coincided with the elevated concentrations of volatile organic compounds such as acetoin and buthanedion. We conclude that the acidifying qualities of composting substrates or bulking material may intensify odour emission from biowaste composts and prolong the early stages of the composting process. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  8. The use of Sphagnum cellulose oxygen isotope ratios in ombrotrophic peatlands as a proxy for paleoclimate.

    Science.gov (United States)

    Taylor, M.; Pendall, E.; Jackson, S.; Booth, R. K.; Nichols, J. E.; Huang, Y.

    2006-12-01

    Developing proxies for discerning paleoclimate that are independent of the pollen record can provide insight into various aspects of climate variability and improve confidence in the interpretation of climate-vegetation interactions. To date, proxies including plant macrofossils, humification indices, testate amoebae, and ratios of n-alkane abundances have been used to infer past climate variability from temperate ombrotrophic peatlands in upper Midwestern North America. These proxies are used to infer past changes in surface-moisture conditions, which in ombrotrophic peatlands is primarily a function of precipitation and temperature. This study investigates the potential uses of stable oxygen isotopes to complement hydrologic proxies. δ18O of surface water and Sphagnum moss cellulose from bogs throughout North America indicates a correlation between average growing season temperatures and δ18O-values. The existence of a modern temperature signal in moss cellulose suggests that δ18O-derived records will not only complement paleohydrological records, but also help assess relative changes in precipitation and temperature. Humification and testate amoebae data from two cores taken from Minden and Irwin Smith Bogs in central and northeastern Michigan have recorded several extreme drought events during the Holocene, including one at 1000 YBP. Comparison of δ18O-values of picked Sphagnum remains to down-core humification and testate amoebae data suggest good temporal correspondence, with the δ18O-values around 1000 YBP indicating a warmer growing season.

  9. Sensibilidad al benzonidazol de cepas de Trypanosoma cruzi sugiere la circulación de cepas naturalmente resistentes en Colombia

    Directory of Open Access Journals (Sweden)

    Ana María Mejía-Jaramillo

    2012-06-01

    Full Text Available Introducción. La enfermedad de Chagas, causada por Trypanosoma cruzi, es uno de los problemas más graves de salud pública en el continente americano. El benzonidazol es uno de los dos medicamentos utilizados para tratar la enfermedad de Chagas. Sin embargo, la variación de la sensibilidad del parásito a este medicamento es una de las principales causas del fracaso del tratamiento. Objetivo. Evaluar la sensibilidad in vitro al benzonidazol de cepas colombianas de T. cruzi de diferentes orígenes y procedencia geográfica. Materiales y métodos. Treinta y tres cepas colombianas de T. cruzi aisladas de humanos, vectores y mamíferos, se analizaron in vitro mediante el micrométodo enzimático de MTT para determinar la concentración inhibitoria 50 (CI50 al benzonidazol. Se estudió la correlación entre la sensibilidad in vitro al medicamento y diferentes parámetros biológicos y eco-epidemiológicos. Resultados. El análisis de sensibilidad al medicamento indicó que el 36 % de las cepas eran sensibles, el 48 %, parcialmente resistentes y, el 16 %, resistentes al benzonidazol. Los análisis de correlación entre las CI50 con algunos parámetros biológicos y eco-epidemiológicos, mostraron diferencias en cuanto a la sensibilidad según el origen biológico y el área geográfica de procedencia de la cepa. Conclusiones. Existe una gran variabilidad en cuanto a la sensibilidad al benzonidazol de las cepas circulantes de T. cruzi en Colombia, lo cual sugiere la presencia de cepas naturalmente resistentes en el país.   doi: http://dx.doi.org/10.7705/biomedica.v32i2.458

  10. Manejo de capim pé-de-galinha em lavouras de soja transgênica resistente ao glifosato

    Directory of Open Access Journals (Sweden)

    André da Rosa Ulguim

    2013-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a resistência de capim pé-de-galinha (Eleusine indica ao glifosato, em lavouras de soja transgênica; avaliar o efeito de aplicações de glifosato em diferentes estádios de desenvolvimento; identificar práticas agronômicas associadas à seleção de biótipos resistentes; e avaliar a eficiência dos herbicidas cletodim, fluazifope-P-butílico, clomazona, glufosinato de amônio e glifosato nas plantas resistentes. Plantas escapes ao tratamento com glifosato foram coletadas em 24 propriedades, no Rio Grande do Sul. As plantas foram cultivadas em casa de vegetação, tendo-se avaliado a sua resistência ao glifosato. Os acessos resistentes foram selecionados e avaliados quanto ao efeito da aplicação do glifosato em diferentes estádios de crescimento e quanto à sensibilidade aos herbicidas. Foi aplicado um questionário aos produtores para identificação das práticas agronômicas associadas às falhas no controle. O controle de E. indica pelo glifosato é mais efetivo com a aplicação em estádios iniciais de desenvolvimento. Práticas agronômicas, como uso contínuo de baixas doses do herbicida, aplicação em estádios de desenvolvimento avançados das plantas daninhas (mais de um afilho e a ausência de rotação de culturas foram relacionadas às falhas de controle observadas. Os herbicidas cletodim, fluazifope-P-butílico e glufosinato de amônio são alternativas eficientes para o controle de E. indica.

  11. Minor effects of long-term ozone exposure on boreal peatland species Eriophorum vaginatum and Sphagnum papillosum

    DEFF Research Database (Denmark)

    Mörsky, SK; Haapala, JK; Rinnan, Riikka

    2011-01-01

    The effects of long-term ozone fumigation on two common peatland plant species, a sedge Eriophorum vaginatum L. and a moss Sphagnum papillosum Lindb., were studied applying peatland microcosms. The peat cores with intact vegetation were cored from an oligotrophic pine fen and partially embedded...

  12. Fractionation of hydrogen, oxygen and carbon isotopes in n-alkanes and cellulose of three Sphagnum species

    NARCIS (Netherlands)

    Brader, A.V.; Winden, J.F.; Bohncke, S.J.P.; Beets, C.J.; Reichart, G.-J.; De Leeuw, J.W.

    2010-01-01

    Compound-specific isotope measurements of organic compounds are increasingly important in palaeoclimate reconstruction. Searching for more accurate peat-based palaeoenvironmental proxies, compound-specific fractionation of stable C, H and O isotopes of organic compounds synthesized by Sphagnum were

  13. Sphagnum-mediated successional pattern in the mixed mire in the Muránska planina Mts (Western Carpathians, Slovakia)

    Czech Academy of Sciences Publication Activity Database

    Hájková, P.; Hájek, Michal

    2004-01-01

    Roč. 59, č. 1 (2004), s. 65-74 ISSN 0006-3088 R&D Projects: GA AV ČR KSK6005114; GA ČR GA206/02/0568 Institutional research plan: CEZ:AV0Z6005908 Keywords : Sphagnum ecology * brown mosses * niche breadth Subject RIV: EF - Botanics Impact factor: 0.207, year: 2004

  14. Decreasing concentrations of metals in Sphagnum mosses in ombrotrophic mires of the Sudety mountains (SW Poland) since late 1980s.

    Science.gov (United States)

    Wojtuń, Bronisław; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Kempers, Alexander J

    2013-06-01

    In this investigation we focus on the evaluation of changes in metal pollution between 1986 until 2011 by Sphagnum species as bioindicators in 100 km part of the Sudety mountains influenced by the former Black Triangle Region. Concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in various Sphagnum species all from ombrotrophic bogs in the Sudety mountains (SW Poland). The tested hypothesis was that overall improvements in pollution control in the former Black Triangle Region between 1986 until recent reduced the amount of metals deposited and accumulated by these plants. Concentrations of Cd, Cr, Cu, Fe, Pb and Zn in Sphagnum species were very high in 1986 indicating a heavy pollution of the examined bogs in this period, and significantly higher than in samples collected in 2011. The PCCA ordination showed the similar pattern in all bogs. In 2011 concentration of the Co was significantly higher in hollow species and concentration of Mn was significantly higher in those from hummocks. Differences between hollow/hummock sites were more important than species-specific abilities of Sphagnum mosses to accumulate metals. Species from hollows were better bioindicators of Co and those from hummocks were better bioindicators of Mn pollution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Effect of a temperature gradient on Sphagnum fallax and its associated living microbial communities: a study under controlled conditions.

    Science.gov (United States)

    Jassey, Vincent E J; Gilbert, Daniel; Binet, Philippe; Toussaint, Marie-Laure; Chiapusio, Geneviève

    2011-03-01

    Microbial communities living in Sphagnum are known to constitute early indicators of ecosystem disturbances, but little is known about their response (including their trophic relationships) to climate change. A microcosm experiment was designed to test the effects of a temperature gradient (15, 20, and 25°C) on microbial communities including different trophic groups (primary producers, decomposers, and unicellular predators) in Sphagnum segments (0-3 cm and 3-6 cm of the capitulum). Relationships between microbial communities and abiotic factors (pH, conductivity, temperature, and polyphenols) were also studied. The density and the biomass of testate amoebae in Sphagnum upper segments increased and their community structure changed in heated treatments. The biomass of testate amoebae was linked to the biomass of bacteria and to the total biomass of other groups added and, thus, suggests that indirect effects on the food web structure occurred. Redundancy analysis revealed that microbial assemblages differed strongly in Sphagnum upper segments along a temperature gradient in relation to abiotic factors. The sensitivity of these assemblages made them interesting indicators of climate change. Phenolic compounds represented an important explicative factor in microbial assemblages and outlined the potential direct and (or) indirect effects of phenolics on microbial communities.

  16. The sensitivity of Sphagnum to surface layer conditions in a re-wetted bog: a simulation study of water stress

    NARCIS (Netherlands)

    Schouwenaars, J.M.; Gosen, A.M.

    2007-01-01

    The behaviour of the water table in re-wetted bogs varies widely between different locations so that recolonising Sphagnum is vulnerable to water stress, especially when the water table is drawn down in summer. It is important to understand how physical site conditions influence the occurrence of

  17. Competition between Sphagnum magellanicum and Eriophorum angustifolium as affected by raised CO2 and increased N deposition

    NARCIS (Netherlands)

    Heijmans, M.M.P.D.; Klees, H.; Berendse, F.

    2002-01-01

    The competition between peat mosses (Sphagnum) and vascular plants as affected by raised CO2 and increased N deposition was studied in a glasshouse experiment by exposing peat monoliths with monocultures and mixtures of Sphagnummagellanicum and Eriophorumangustifolium to ambient (350 ppmv) or raised

  18. The effects of water management on the CO2 uptake of Sphagnum moss in a reclaimed peatland

    Directory of Open Access Journals (Sweden)

    C.M. Brown

    2017-07-01

    Full Text Available To harvest Sphagnum on a cyclic basis and rapidly accumulate biomass, active water management is necessary. The goal of this study is to determine the hydrological conditions that will maximise CO2 uptake in Sphagnum farming basins following the moss-layer transfer technique. Plot CO2 uptake doubled from the first growing season to the second, but growth was not uniform across the site. Results indicate that the seasonal oscillations in water table (WT position were more important than actual WT position for estimating Sphagnum ground cover and CO2 uptake when the seasonal WT is shallow (< -25 cm. Plots with higher productivity had a WT range (seasonal maximum – minimum less than 15 cm, a WT position which did not fluctuate more than ± 7.5 cm, and a low WT standard deviation. Each basin was a CO2 source during the second growing season, and seasonal modelled NEE ranged from 107.1 to 266.8 g CO2 m-2. Decomposition from the straw mulch accounted for over half of seasonal respiration, and the site is expected to become a CO2 sink as the straw mulch decomposes and moss cover increases. This study highlights the importance of maintaining stable moisture conditions to increase Sphagnum growth and CO2 sink functions.

  19. Application of sphagnum peat, calcium carbonate and hydrated lime for immobilizing radioactive and hazardous contaminants in the subsurface

    International Nuclear Information System (INIS)

    Longmire, P.A.; Thomson, B.M.; Eller, P.G.; Barr, M.E.

    1991-01-01

    Batch experiments, mineralogical studies, and geochemical modeling were conducted to evaluate the effectiveness of sphagnum peat, calcium carbonate, and hydrated lime in removing dissolved concentrations of As, Mo, NO 3 , and U present in uranium-tailings pore water at Gunnison, Colorado. Amounts of As, Mo, and U removal by sphagnum peat, calcium carbonate, and hydrated lime at 5.0,2.5, and 2.5 wt.%, respectively, were typically above 97%. Nitrate removal ranged between 55 and 80%. Significant contaminant removal was achieved by sphagnum peat alone at pH 3.18. Results from base potentiometric titration and IR spectroscopy investigations suggest that U(VI) binds onto carboxylate and phenolate groups. Addition of 2.5 wt.% hydrated lime to the acidic tailings increased Mo concentrations by a factor of 2 under moderately alkaline conditions (pH 12). During neutralization of tailings-pore water, precipitation of ferric oxyhydroxides may provide additional removal of As, Mo, and U(VI) from solution through adsorption and coprecipitation processes. Sphagnum peat and other forms of solid organic matter effectively remove anthropogenic organic compounds from solution through hydrophobic sorption and partitioning processes

  20. Acidicapsa borealis gen. nov., sp. nov. and Acidicapsa ligni sp. nov., subdivision 1 Acidobacteria from Sphagnum peat and decaying wood

    NARCIS (Netherlands)

    Kulichevskaya, I.S.; Kostina, L.A.; Valášková, V.; Rijpstra, I.C.; Sinninghe Damsté, J.S.; De Boer, W.; Dedysh, S.N.

    2012-01-01

    Two strains of subdivision 1 Acidobacteria, namely the pink-pigmented bacterium KA1T and the colorless isolate WH120T, were obtained from acidic Sphagnum peat and wood under decay by the white-rot fungus Hyploma fasciculare, respectively. Cells of these isolates are Gram-negative, non-motile, short

  1. Singulisphaera rosea sp. nov., a planctomycete from acidic Sphagnum peat, and emended description of the genus Singulisphaera

    NARCIS (Netherlands)

    Kulichevskaya, I.S.; Detkova, E.N.; Bodelier, P.L.E.; Rijpstra, W.I.C.; Sinninghe Damsté, J.S.; Dedysh, S.N.

    2012-01-01

    A novel species, Singulisphaera rosea sp. nov., is proposed for aerobic, pink-pigmented, budding bacterium isolated from an acidic Sphagnum peat bog of northwestern Russia. This bacterium, designated strain S26T, has non-motile, spherical cells that occur singly, in pairs or in short chains and

  2. Electroconvulsive therapy in treatment-resistant mania: case reports A Eletroconvulsoterapia no tratamento da mania resistente: relatos de casos

    Directory of Open Access Journals (Sweden)

    Marcia Britto de Macedo Soares

    2002-02-01

    Full Text Available Electroconvulsive therapy is known to be effective in the treatment of mood disorders, more specifically for depression and mania. Although a large body of evidence confirms the efficacy of electroconvulsive therapy in the treatment of mania, few prospective studies have been done to assess its effectiveness in treatment-resistant manic episodes. These case reports describe the initial results of a study that is being conducted to evaluate the efficacy of Electroconvulsive therapy among treatment-resistant bipolar patients. METHODS: Three manic patients (according to DSM-IV criteria who were considered treatment-resistant underwent a series of 12 bilateral Electroconvulsive therapy sessions. Before the treatment and then weekly, they were evaluated with the following rating scales: Young Mania Rating Scale, Hamilton Rating Scale for Depression, Brief Psychiatric Rating Scale, and Clinical Global Impressions-Bipolar Version. RESULTS: The 3 patients showed a satisfactory response to Electroconvulsive therapy, although some differences in the course of response were observed. CONCLUSION: These case reports suggest that Electroconvulsive therapy needs further evaluation for the treatment of resistant bipolar patients.A Eletroconvulsoterapia é uma alternativa reconhecidamente eficaz no tratamento dos transtornos do humor. Embora vários estudos tenham confirmado a eficácia desta modalidade terapêutica no tratamento da mania aguda, poucos estudos foram realizados em pacientes maníacos resistentes à farmacoterapia. Esses relatos de casos descrevem resultados preliminares de um projeto de pesquisa que tem por objetivo avaliar a eficácia da Eletroconvulsoterapia no tratamento de transtornos bipolares resistentes. MÉTODOS: Três pacientes com diagnóstico de mania (de acordo com os critérios do DSM-IV, considerados resistentes ao tratamento medicamentoso, foram submetidos a 12 aplicações bilaterais de Eletroconvulsoterapia. Antes do tratamento e

  3. Aislamiento de Staphylococcus aureus meticilino resistente en abscesos de mama en una Maternidad Pública

    Directory of Open Access Journals (Sweden)

    Cristina Boccaccio

    2014-06-01

    Full Text Available La mastitis y los abscesos de mama representan un factor de riesgo para el abandono de la lactancia. Se incluyen dentro de las infecciones de piel y partes blandas y comparten los cambios epidemiológicos que llevan a replantear el tratamiento empírico inicial. Se estudiaron 137 casos de abscesos de mama desde enero de 2007 a diciembre de 2011. Se analizó incidencia, días postparto, factores de riesgo, datos microbiológicos y tratamiento antibiótico. Desde 2007a 2011 se observó un constante aumento de la incidencia de casos: 0.19 vs. 0.84% (p < 0.001. Días postparto de aparición del absceso 41.9 ± 35.8 días (Media ± DE, primiparidad 70.6%. Los factores de riesgo más frecuentemente encontrados fueron grietas del pezón e ingurgitación mamaria (95%. Staphylococcus aureus (SA fue el responsable de 82.3 a 95.0% de los abscesos según los años; la resistencia a oxacilina de las cepas de SA superó el 60%. Las cepas aisladas de SA meticilino resistentes (SAMR fueron sensibles a eritromicina clindamicina, gentamicina, rifampicina, ciprofloxacina y trimetroprima-sulfametoxasol en diferentes porcentajes según los años. Requirieron drenaje el 100% de los casos; en 60% el tratamiento empírico inicial fue inadecuado. Continuaron amamantando 90% de las madres. Estos datos enfatizan la necesidad de prevenir los factores de riesgo: grietas del pezón e ingurgitación mamaria. La modificación del tratamiento antibiótico inicial requiere el estudio bacteriológico de las infecciones de piel y partes blandas dado que la prevalencia de SAMR no es uniforme y varía en diferentes poblaciones y ubicaciones geográficas.

  4. Sistema de autoconstrucción sismorresistente: características resistentes y proceso constructivo

    Directory of Open Access Journals (Sweden)

    Orta, B.

    2016-06-01

    Full Text Available The dwelling construction with soil, adobe or brick without call for technical advice is very typical in countries in process of development that are in areas of high seismic risk. To give an answer to the problem of earthquake building using these materials, providing simplicity of construction, we have worked for years in the use of the Integral Masonry System (IMS. The IMS is a system that, used combined with native materials, has earthquake resistant properties and its ease of implementation makes it suitable for self-build earthquake-resistant dwellings. This article describes the IMS, develops the constructive process applied to a type of two storey houses, and shows the seismic behaviour by means of the results obtained in the three test campaigns. The originality of the system lies in the use of a single type of prefabricated trusses, intertwined in the three spatial directions allowing create a dimensional mesh.La autoconstrucción con tierra, adobe o ladrillo es muy habitual en los países en vías de desarrollo que están en zonas de alto riesgo sísmico. Ante la necesidad de dar respuesta al problema, aportando sencillez constructiva, hemos trabajado desde hace años en el empleo del Sistema de Albañilería Integral (SAI. El SAI es un sistema que, combinado con materiales autóctonos, aporta resistencia sísmica y su facilidad de ejecución lo hace adecuado para la autoconstrucción de viviendas antisísmicas. Este artículo describe el SAI, desarrolla el proceso constructivo aplicado a una vivienda tipo de dos alturas y muestra su comportamiento sismo-resistente mediante los resultados obtenidos en tres campañas de ensayos. La originalidad del sistema radica en el empleo de un solo tipo de armaduras prefabricadas en forma de cercha que se entrelazan entre si en las tres direcciones del espacio permitiendo crear una malla tridimensional.

  5. Mastite bovina causada por Staphylococcus spp. resistentes à meticilina: revisão de literatura

    Directory of Open Access Journals (Sweden)

    José Givanildo Silva

    Full Text Available RESUMO: Staphylococcus spp. são os micro-organismos mais relacionados a casos de mastite bovina. Algumas cepas destes micro-organismos têm apresentado fatores de virulência como genes de resistência a antimicrobianos com destaque para a resistência à meticilina que é um problema de saúde pública. Esta revisão de literatura tem o objetivo de compilar dados sobre a mastite bovina causada por Staphylococcus spp. resistente à meticilina (MRS. Apesar desse antimicrobiano não ser comumente utilizado no tratamento das mastites, a frequência de casos de infecção da glândula mamária causada por MRS tem variado entre 1,34 a 47,6%. Acredita-se que o contato dos humanos com animais positivos para MRS e vice-versa favoreça a transmissão deste patógeno entre as espécies, contribuindo para a variação nas taxas de infecção. A detecção de MRS pode ser realizada por meio de provas fenotípicas, moleculares ou sorológicas e as medidas de controle devem contemplar a identificação dos casos, segregação dos animais, estudo epidemiológico da fonte de infecção do rebanho, além da constante limpeza e higienização do ambiente de confinamento, equipamentos e utensílios de ordenha. Casos de mastite ocasionados por esse patógeno assumem relevância para a saúde pública, pois a ingestão de leite e/ou derivados contaminados podem desencadear a transferência de MRS para seres humanos. Com isso, é necessário um alerta constante quanto à vigilância epidemiológica em fazendas leiteiras.

  6. Estudio metabólico y molecular de cultivos bacterianos degradadores de hidrocarburos aromáticos policíclicos (PAH) y resistentes a metales pesados

    OpenAIRE

    Cecotti, Martina; Morelli, Irma Susana; Coppotelli, Bibiana

    2015-01-01

    La contaminación mixta con PAH y metales pesados conlleva dificultades debido a la potencial toxicidad del metal, limitando la supervivencia solo a los microorganismos que toleren ambos contaminantes. El estudio de cepas degradadoras de PAH y resistentes a metales pesados promete proporcionar herramientas claves para el proceso de biorremediación. Este trabajo tuvo como objetivos la selección, identificación y caracterización de cepas degradadoras de PAH y resistentes a metales pesados aislad...

  7. Phylogenetic or environmental control on the organo-chemical composition of Sphagnum mosses?

    Science.gov (United States)

    Limpens, Juul; Nilsson, Mats

    2014-05-01

    Decomposition of organic material is one of the key processes that determines the size of the soil-feedback to global warming, but it is also a process surrounded with one of the largest uncertainties, making understanding its mechanistic drivers of crucial importance. In organic soils decomposition is closely determined by the organo-chemical composition of the litter entering the soil. But what, in turn drives the organo-chemical composition? Is it an emergent feature of the environment the species producing the litter grow in, or is it an evolutionary trait that can be tracked through the species' phylogeny? We set out to answer this question for one of the most import peat-forming plants on earth: the genus Sphagnum. We sampled 18 Sphagnum species, about equally distributed over 6 sites spanning a wide range of environmental conditions: most species were collected at multiple sites. For all species we characterised the chemical composition, focussing on three functional chemistry groups: (i) mineral elements, (ii) carbohydrate polymers (iii) non-carbohydrate polymers (aromatic and aliphatic compounds) . For each group of compounds we used multivariate statistical techniques to derive the degree of variation explained by environment: (site, position within site) and phylogeny (sections within genus Sphagnum). We found that the variation in mineral element concentrations was mostly explained by environment, with the biggest differences in the concentrations of basic cat-ions calcium and magnesium. In contrast, the variation in carbohydrates was mostly explained by phylogeny, with clear associations between sections and monosaccharides. The monosaccharide rhamnose was associated with species from the Acutifolia section known for their poor degradability, whereas xylose and galactose were closely associated with degradable species from the Cuspidata section. The composition non-carbohydrate polymers took an intermediate position: both environment and phylogeny

  8. Staphylococcus aureus resistente a meticilina adquirido en la comunidad aislados en tres hospitales de Lima-Perú

    Directory of Open Access Journals (Sweden)

    Jesús Tamariz

    2010-01-01

    Full Text Available Staphylococcus aureus es un importante patógeno involucrado en una serie de infecciones e intoxicaciones, presenta múltiples factores de virulencia y su impacto se incrementa por su notable resistencia a los antimicrobianos. Objetivo: Determinar la frecuencia de Staphylococcus aureus meticilino resistente adquiridos en la comunidad, en hospitales de Lima- Perú. Material y métodos: Se realizó un estudio descriptivo multicéntrico. La resistencia a meticilina se determinó por el método Oxacillin Agar Screen. El origen de la cepa fue determinado mediante los criterios de los CDC; la Leucocidina de Panton Valentine fue identificada por métodos moleculares. Resultados: Se aislaron 276 cepas de Staphylococcus aureus, 160 fueron resistentes a meticilina (58%, 9 de ellas fueron identificadas como adquiridas en la comunidad (5,6%. La PVL fue identificada en 25 cepas (9,1%, 14 fueron MSSA y 11 MRSA, de éstas últimas solo 4 fueron MRSAcom, 7 fueron MRSAhosp (p<0,001. Conclusiones: El estudio revela niveles elevados de resistencia a meticilina, pero niveles bajos de MRSAcom. En nuestro medio la presencia de PVL no constituiría un marcador para la identificación de los MRSAcom. (Rev Med Hered 2010;21:4-10.

  9. Late Holocene palaeohydrological changes in a Sphagnum peat bog from NW Romania based on testate amoebae

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    Andrei-Cosmin Diaconu

    2016-04-01

    Full Text Available This paper investigates the possibility of reconstructing the palaeohydrological changes in an active Sphagnum peat bog from north-western Romania using testate amoebae fauna and organic matter content determined by loss on ignition (LOI. In total 28 taxa of testate amoebae were identified of which 11 were frequent enough to present a remarkable ecological significance. Based on the relative abundance of these taxa nine zones were identified, crossing from very wet to dry climate conditions. The wet periods identified are characterized by taxa like Centropyxis cassis, Amphitrema flavum and Hyalosphenia papilio, while in the dry periods Difflugia pulex and Nebela militaris thrive. We showed that combining qualitative information regarding hydrological preferences with the quantitative percentage data from the fossil record it is possible to obtain information regarding major surface moisture changes from the peat bog surface. Furthermore we identified a link between distribution of testate amoebae assemblages, organic matter variation and minerogenic material.

  10. Mineral content in Sphagnum mosses from ombrotrophic bogs of southwestern Poland: pattern in species and elements

    Directory of Open Access Journals (Sweden)

    Bronisław Wojtuń

    2014-01-01

    Full Text Available Major elements (N, P, K, Ca, Mg, Na, Fe were analyzed in 11 Sphagnum species from ombrotrophic bogs in southwestern Poland. The material included species from wet to dry microsites. The highest levels of elements were recorded for S. lindbergii, whereas S. balticum and S. cuspidatum were poorest in elements. The microhabitat gradient from hummock to hollow species is clearly reflected by decreasing concentrations of Ca and Mg, and increasing concentration of Na. Phosphorus, K and N were much more enriched into moss tissues than the remaining elements. These three nutrients were also accumulated in the upper green parts of mosses, while the concentrations of Na and Fe were higher in the bottom brown parts. There were no differences in Ca and Mg between the green and brown segments.

  11. Cultivable mycobacteria in sphagnum vegetation of moors in South Sweden and coastal Norway.

    Science.gov (United States)

    Kazda, J; Müller, K; Irgens, L M

    1979-04-01

    Intact sphagnum vegetation from moors in south Sweden and coastal areas of west Norway contained cultivable mycobacteria in 32% and 30% of the specimens, respectively. This frequency of specimens is lower than the 50% previously found in the partly altered moors of northwestern Germany, but the Scandinavian moors contained a larger variety of species. On both intact and altered moors M. chelonei and M. sphagni sp. nov. were found, the latter a homologous group of 151 strains. In south Sweden the highest frequency was found in S. balticum, S. recurvum. S. tenellum and S. compactum & molle. (40-65%). In coastal Norway the highest frequency was found in S. rubellum (48%) which offers favourable conditions for the accumulation of solar energy due to the red brown colour in the upper parts. Combined with a high humidity in coastal Norway in summer, this may contribute to the growth of mesophilic mycobacteria. A significant affinity of M. chelonei to S. tenellum was stated.

  12. [Effects of shading on two Sphagnum species growth and their interactions].

    Science.gov (United States)

    Ma, Jin-Ze; Bu, Zhao-Jun; Zheng, Xing-Xing; Li, Shan-Lin; Zeng, Jing; Zhao, Gao-Lin

    2012-02-01

    Taking Sphagnum palustre and S. fallax as test materials, this paper studied their growth and interactions under shading. In monoculture, shading promoted the height growth of S. palustre markedly, but had no effect on the growth of S. fallax and the biomass and branching of S. palustre. In mixed culture, S. fallax suppressed the increase of biomass and branching of S. palustre, while S. palustre had no effects on S. fallax. With the increase of shading stress, the competition of neighbour on S. fallax intensified. When the stress increased further, neighbor effect on S. fallax tended to be positive. However, the effect of neighbour on S. palustre was always competitive and did not change with the increase of shading stress.

  13. Inhibitory effect of Sphagnum palustre extract and its bioactive compounds on aromatase activity

    Directory of Open Access Journals (Sweden)

    Hee Jeong Eom

    2016-09-01

    Full Text Available Sphagnum palustre (a moss has been traditionally used in Korea for the cure of several diseases such as cardiac pain and stroke. In this research, the inhibitory effect of S. palustre on aromatase (cytochrome P450 19, CYP19 activity was studied. [1β-3H] androstenedione was used as a substrate and incubated with S. palustre extract and recombinant human CYP19 in the presence of NADPH. S. palustre extract inhibited aromatase in a concentration-dependent manner (IC50 value: 36.4 ± 8.1 µg/mL. To elucidate the major compounds responsible for the aromatase inhibitory effects of S. palustre extract, nine compounds were isolated from the extract and tested for their inhibition of aromatase activity. Compounds 1, 6, and 7 displayed aromatase inhibition, while the inhibition by the other compounds was negligible.

  14. Net ecosystem exchange in a sedge-sphagnum fen at the South of West Siberia, Russia

    Science.gov (United States)

    Dyukarev, Egor

    2017-04-01

    The model of net ecosystem exchange was used to study the influence of different environmental factors and to calculate daily and growing season carbon budget for minerotrophic fen at South of West Siberia, Russia. Minerotrophic sedge-sphagnum fen occupies the central part of the Bakcharskoe bog. The model uses air and soil temperature, incoming photosynthetically active radiation, and leaf area index as the explanatory factors for gross primary production, heterotrophic and autotrophic respiration. The model coefficients were calibrated using data collected by automated soil CO2 flux system with clear long-term chamber. The studied ecosystem is a sink of carbon according to modelling and observation results. This study was supported by Russian Foundation for Basic Researches (grant numbers 16-07-01205 and 16-45-700562.

  15. Differences in response of two Sphagnum species to elevated CO2 and nitrogen input

    International Nuclear Information System (INIS)

    Jauhiainen, J.; Vasander, H.; Silvola, J.

    1992-01-01

    Cushions of Sphagnum fuscum and S. angustifolium were grown in the laboratory in four different CO 2 concentrations (350, 700, 1000 and 2000 ppm) and N deposition levels (0, 10, 30 and 100 kg/ha - 1 a - 1). The same N deposition levels were also applied in the field. CO 2 concentration increases both the shoot density and dry mass of S. fuscum but decreased the length increment. There was no net effect on production. For S. angustifolium, shoot density did not alter with elevated CO 2 concentration but the CO 2 induced increment in dry mass and length caused increased production. S. angustifolium suffered from nutrient deficiency on the 0kg/ha - 1 a - 1 treatment and S. fuscum had difficulties to survive at heaviest N load. No clear trends in length increment or cover was noticed in the field study during the first year

  16. Acidity of sphagnum and its relation to chalk and mineral salts

    Energy Technology Data Exchange (ETDEWEB)

    Skene, M

    1915-01-01

    In addition to the criticism and elucidation of various other points, the chief conclusions which may be drawn from the preceding pages are: (1) There is a variation in acidity and in sensitiveness to chalk between the different species of sphagnum. (2) There is a correlation between degree of acidity and degree of sensitiveness. (3) The connection between the two is indirect, not direct. (4) The sphagna thrive in acid solutions: the injurious effect of chalk, and of alkalies in general, is due to the substitution of an alkaline for an acid reaction. (5) Mineral solutions are generally physiologically harmless, but may be ecologically harmful. (6) The sphagna do actually utilize in growth bases held absorbed by the acid compounds of the cell-walls.

  17. Novel insights on the structure and composition of pseudostomata of Sphagnum.

    Science.gov (United States)

    Merced, Amelia

    2015-03-01

    The occurrence of stomata on sporophytes of mosses and hornworts is congruent with a single origin in land plants. Although true stomata are absent in early-divergent mosses, Sphagnum has specialized epidermal cells, pseudostomata, that partially separate but do not open to the inside. This research examined two competing hypotheses that explain the origin of pseudostomata: (1) they are modified stomata, or (2) they evolved from epidermal cells independently from stomata.• Capsule anatomy and ultrastructure of pseudostomata were studied using light and electron microscopy, including immunolocalization of pectins.• Cell walls in pseudostomata are thin, two-layered, and rich in pectins, similar to young moss stomata, including the presence of cuticle on exterior walls. Outer and ventral walls have a thick cuticle that suggests that initial separation of ventral walls involves cuticle deposition as in true stomata. Further mechanical separation between ventral walls does not form a pore and occurs as the capsule dries.• As in moss stomata, pseudostomata wall architecture and behavior facilitate capsule dehydration, shape change, and dehiscence, supporting a common function. The divergent structure and fate of pseudostomata may be explained by the retention of Sphagnum sporophytes within protective leaves until nearly mature. Ultrastructural and immunocytological data suggest that pseudostomata are related to stomata but do not conclusively support either hypothesis. Solving the relationship of early land plants is critical to understanding stomatal evolution. Pseudostomata are structurally and anatomically unique, but their relationship to true stomata remains to be determined. © 2015 Botanical Society of America, Inc.

  18. Bacterial populations and environmental factors controlling cellulose degradation in an acidic Sphagnum peat.

    Science.gov (United States)

    Pankratov, Timofey A; Ivanova, Anastasia O; Dedysh, Svetlana N; Liesack, Werner

    2011-07-01

    Northern peatlands represent a major global carbon store harbouring approximately one-third of the global reserves of soil organic carbon. A large proportion of these peatlands consists of acidic Sphagnum-dominated ombrotrophic bogs, which are characterized by extremely low rates of plant debris decomposition. The degradation of cellulose, the major component of Sphagnum-derived litter, was monitored in long-term incubation experiments with acidic (pH 4.0) peat extracts. This process was almost undetectable at 10°C and occurred at low rates at 20°C, while it was significantly accelerated at both temperature regimes by the addition of available nitrogen. Cellulose breakdown was only partially inhibited in the presence of cycloheximide, suggesting that bacteria participated in this process. We aimed to identify these bacteria by a combination of molecular and cultivation approaches and to determine the factors that limit their activity in situ. The indigenous bacterial community in peat was dominated by Alphaproteobacteria and Acidobacteria. The addition of cellulose induced a clear shift in the community structure towards an increase in the relative abundance of the Bacteroidetes. Increasing temperature and nitrogen availability resulted in a selective development of bacteria phylogenetically related to Cytophaga hutchinsonii (94-95% 16S rRNA gene sequence similarity), which densely colonized microfibrils of cellulose. Among isolates obtained from this community only some subdivision 1 Acidobacteria were capable of degrading cellulose, albeit at a very slow rate. These Acidobacteria represent indigenous cellulolytic members of the microbial community in acidic peat and are easily out-competed by Cytophaga-like bacteria under conditions of increased nitrogen availability. Members of the phylum Firmicutes, known to be key players in cellulose degradation in neutral habitats, were not detected in the cellulolytic community enriched at low pH. © 2011 Society for

  19. Atmospheric Pb and Ti accumulation rates from Sphagnum moss: dependence upon plant productivity.

    Science.gov (United States)

    Kempter, H; Krachler, M; Shotyk, W

    2010-07-15

    The accumulation rates of atmospheric Pb and Ti were obtained using the production rates of Sphagnum mosses collected in four ombrotrophic bogs from two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and one year later the production of plant matter was harvested. Metal concentrations were determined in acid digests using sector field ICP-MS employing well established analytical procedures. Up to 12 samples (40 x 40 cm) were collected per site, and 6-10 sites were investigated per bog. Variations within a given sampling site were in the range 2.3-4x for Pb concentrations, 1.8-2.5x for Ti concentrations, 3-8.3x for Pb/Ti, 5.6-7.8x for Pb accumulation rates, and 2.3-6.4x for Ti accumulation rates. However, the median values of these parameters for the sites (6-10 per bog) were quite consistent. The mosses from the bogs in NBF exhibited significantly greater productivity (187-202 g m(-2) a(-1)) compared to the OB peat bogs (71-91 g m(-2) a(-1)), and these differences had a pronounced effect on the Pb and Ti accumulation rates. Highly productive mosses showed no indication of a "dilution effect" of Pb or Ti concentrations, suggesting that more productive plants were simply able to accumulate more particles from the air. The median rates of net Pb accumulation by the mosses are in excellent agreement with the fluxes obtained by direct atmospheric measurements at nearby monitoring stations in both regions (EMEP and MAPESI data).

  20. Above- and belowground linkages in Sphagnum peatland: climate warming affects plant-microbial interactions.

    Science.gov (United States)

    Jassey, Vincent E J; Chiapusio, Geneviève; Binet, Philippe; Buttler, Alexandre; Laggoun-Défarge, Fatima; Delarue, Frédéric; Bernard, Nadine; Mitchell, Edward A D; Toussaint, Marie-Laure; Francez, André-Jean; Gilbert, Daniel

    2013-03-01

    Peatlands contain approximately one third of all soil organic carbon (SOC). Warming can alter above- and belowground linkages that regulate soil organic carbon dynamics and C-balance in peatlands. Here we examine the multiyear impact of in situ experimental warming on the microbial food web, vegetation, and their feedbacks with soil chemistry. We provide evidence of both positive and negative impacts of warming on specific microbial functional groups, leading to destabilization of the microbial food web. We observed a strong reduction (70%) in the biomass of top-predators (testate amoebae) in warmed plots. Such a loss caused a shortening of microbial food chains, which in turn stimulated microbial activity, leading to slight increases in levels of nutrients and labile C in water. We further show that warming altered the regulatory role of Sphagnum-polyphenols on microbial community structure with a potential inhibition of top predators. In addition, warming caused a decrease in Sphagnum cover and an increase in vascular plant cover. Using structural equation modelling, we show that changes in the microbial food web affected the relationships between plants, soil water chemistry, and microbial communities. These results suggest that warming will destabilize C and nutrient recycling of peatlands via changes in above- and belowground linkages, and therefore, the microbial food web associated with mosses will feedback positively to global warming by destabilizing the carbon cycle. This study confirms that microbial food webs thus constitute a key element in the functioning of peatland ecosystems. Their study can help understand how mosses, as ecosystem engineers, tightly regulate biogeochemical cycling and climate feedback in peatlands. © 2012 Blackwell Publishing Ltd.

  1. Cellulose and Lignin Carbon Isotope Signatures in Sphagnum Moss Reveal Complementary Environmental Properties

    Science.gov (United States)

    Loisel, J.; Nichols, J. E.; Kaiser, K.; Beilman, D. W.; Yu, Z.

    2016-12-01

    The carbon isotope signature (δ13C) of Sphagnum moss is increasingly used as a proxy for past surface wetness in peatlands. However, conflicting interpretations of these carbon isotope records have recently been published. While the water film hypothesis suggests that the presence of a thick (thin) water film around hollow (hummock) mosses leads to less (more) negative δ13C values, the carbon source hypothesis poses that a significant (insignificant) amount of CH4 assimilation by hollow (hummock) mosses leads to more (less) negative δ13C values. To evaluate these competing mechanisms and their impact on moss δ13C, we gathered 30 moss samples from 6 peatlands in southern Patagonia. Samples were collected along a strong hydrological gradient, from very dry hummocks (80 cm above water table depth) to submerged hollows (5 cm below water surface). These peat bogs have the advantage of being colonized by a single cosmopolitan moss species, Sphagnum magellanicum, limiting potential biases introduced by species-specific carbon discrimination. We measured δ13C from stem cellulose and leaf waxes on the same samples to quantify compound-specific carbon signatures. We found that stem cellulose and leaf-wax lipids were both strongly negatively correlated with moss water content, suggesting a primary role of water film thickness on carbon assimilation. In addition, isotopic fractionation during wax synthesis was greater than for cellulose. This offset decreases as conditions get drier, due to (i) a more effective carbon assimilation, or (ii) CH4 uptake through symbiosis with methanotrophic bacteria within the leaves of wet mosses. Biochemical analysis (carbohydrates, amino acids, hydrophenols, cutin acids) of surface moss are currently being conducted to characterize moss carbon allocation under different hydrological conditions. Overall, this modern calibration work should be of use for interpreting carbon isotope records from peatlands.

  2. High Throughput Sequencing to Detect Differences in Methanotrophic Methylococcaceae and Methylocystaceae in Surface Peat, Forest Soil, and Sphagnum Moss in Cranesville Swamp Preserve, West Virginia, USA

    Science.gov (United States)

    Lau, Evan; Nolan, Edward J.; Dillard, Zachary W.; Dague, Ryan D.; Semple, Amanda L.; Wentzell, Wendi L.

    2015-01-01

    Northern temperate forest soils and Sphagnum-dominated peatlands are a major source and sink of methane. In these ecosystems, methane is mainly oxidized by aerobic methanotrophic bacteria, which are typically found in aerated forest soils, surface peat, and Sphagnum moss. We contrasted methanotrophic bacterial diversity and abundances from the (i) organic horizon of forest soil; (ii) surface peat; and (iii) submerged Sphagnum moss from Cranesville Swamp Preserve, West Virginia, using multiplex sequencing of bacterial 16S rRNA (V3 region) gene amplicons. From ~1 million reads, >50,000 unique OTUs (Operational Taxonomic Units), 29 and 34 unique sequences were detected in the Methylococcaceae and Methylocystaceae, respectively, and 24 potential methanotrophs in the Beijerinckiaceae were also identified. Methylacidiphilum-like methanotrophs were not detected. Proteobacterial methanotrophic bacteria constitute Sphagnum moss) or co-occurred in both Sphagnum moss and peat. This study provides insights into the structure of methanotrophic communities in relationship to habitat type, and suggests that peat and Sphagnum moss can influence methanotroph community structure and biogeography. PMID:27682082

  3. Sphagnum physiology in the context of changing climate: emergent influences of genomics, modelling and host-microbiome interactions on understanding ecosystem function.

    Science.gov (United States)

    Weston, David J; Timm, Collin M; Walker, Anthony P; Gu, Lianhong; Muchero, Wellington; Schmutz, Jeremy; Shaw, A Jonathan; Tuskan, Gerald A; Warren, Jeffrey M; Wullschleger, Stan D

    2015-09-01

    Peatlands harbour more than one-third of terrestrial carbon leading to the argument that the bryophytes, as major components of peatland ecosystems, store more organic carbon in soils than any other collective plant taxa. Plants of the genus Sphagnum are important components of peatland ecosystems and are potentially vulnerable to changing climatic conditions. However, the response of Sphagnum to rising temperatures, elevated CO2 and shifts in local hydrology have yet to be fully characterized. In this review, we examine Sphagnum biology and ecology and explore the role of this group of keystone species and its associated microbiome in carbon and nitrogen cycling using literature review and model simulations. Several issues are highlighted including the consequences of a variable environment on plant-microbiome interactions, uncertainty associated with CO2 diffusion resistances and the relationship between fixed N and that partitioned to the photosynthetic apparatus. We note that the Sphagnum fallax genome is currently being sequenced and outline potential applications of population-level genomics and corresponding plant photosynthesis and microbial metabolic modelling techniques. We highlight Sphagnum as a model organism to explore ecosystem response to a changing climate and to define the role that Sphagnum can play at the intersection of physiology, genetics and functional genomics. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  4. Prevalencia y características de los pacientes con hipertensión arterial resistente y enfermedad renal crónica

    Directory of Open Access Journals (Sweden)

    Úrsula Verdalles

    2016-09-01

    Conclusión: La prevalencia de HTA resistente aumenta con la edad, el grado de ERC y la albuminuria. Estrategias como el tratamiento con antagonistas de receptores de aldosterona se asocian con un mejor control tensional en este grupo de pacientes y disminuyen su prevalencia.

  5. Frecuencia de aislamiento de Staphylococcus spp meticilina resistentes y Enterococcus spp vancomicina resistentes en hospitales de Cuba Frequency of methicilline-resistant Staphylococcus spp and vancomycin-resistant Enterococcus spp isolates in Cuban hospitals

    Directory of Open Access Journals (Sweden)

    Leonora González Mesa

    2005-12-01

    Full Text Available La resistencia a meticilina en el género Staphylococcus spp es un problema creciente en el ámbito mundial. La producción de una PBP alterada (PBP2a con baja afinidad a betalactámicos, mediada por el gen mec A, es la responsable de esta resistencia. Mientras que los Staphylococcus spp todavía permanecen sensibles a vancomicina, algunos Enterococcus spp han adquirido la capacidad de neutralizar esta droga. En nuestro país no se conocen datos actualizados sobre la tasa de infección por S. aureus meticilina resistente (SAMR, ni sobre la circulación de este germen en la comunidad, tampoco existen reportes de Enterococcus spp vancomicina resistente (EVR. En este estudio fueron analizadas 774 cepas, colectadas en hospitales del país. Se determinó el mecanismo de resistencia utilizando métodos sugeridos por las guías NCCLS. El 9.3 % (23 de los S. aureus aislados en los hospitales y 4.0% (7 S. aureus aislados en la comunidad, fueron SAMR, portadores del gen mec A, el 69.9 % (72 de Staphylococcus coagulasa negativo, fueron resistentes a oxacilina. En la detección del Enterococcus spp vancomicina resistente (EVR, se encontró una cepa portadora de este fenotipo. Nuestros resultados revelan que en nuestro país los SAMR no son un problema en los hospitales, ni en el ambiente comunitario, a pesar de que se reporta por primera vez la circulación de estos en la comunidad y la circulación de EVR en el ambiente hospitalario, su frecuencia es muy baja lo que refleja los avances obtenidos en la aplicación de políticas encaminadas a racionalizar el uso y consumo de antibióticos.Resistance to methicilline in Staphylococcus spp genus is a growing problem worldwide. The production of an altered penicillin-fixing protein with low mecA gen-mediated affinity to beta-lactams is responsible for this resistance. Although Staphylococcus spp still remain susceptible to vancomycin, some Enterococcus spp have acquired the capacity of neutralizing this drug. In

  6. Potential NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species

    Energy Technology Data Exchange (ETDEWEB)

    Jauhiainen, J [Joensuu Univ. (Finland). Dept. of Biology; Wallen, B; Malmer, N [Lund Univ. (Sweden). Dept. of Plant Ecology

    1997-12-31

    The objective of this research is to test differences in NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species under laboratory conditions. The studied species represent two gradients: the minerotrophy-ombrotrophy (mire margin - mire expanse) gradient, and the hummock-hollow gradient. There are distinct differences in the uptake rate between various Sphagnum species and these differences seem to be due to both structural and environmental factors: (1) on individual basis the highest uptake rate is in species with large capitulum and high number of ion exchange sites i.e. lawn species, (2) on dry mass basis the most effective species are the hummock species though they have a low DM, (3) from the ecosystem point of view, hummock species with high number of shoots per unit area and high uptake rate on dry mass basis, are the most effective species in filtering available nitrogen. (1 ref.)

  7. Active moss biomonitoring of trace elements with Sphagnum girgensohnii moss bags in relation to atmospheric bulk deposition in Belgrade, Serbia

    International Nuclear Information System (INIS)

    Anicic, M.; Tasic, M.; Frontasyeva, M.V.; Tomasevic, M.; Rajsic, S.; Mijic, Z.; Popovic, A.

    2009-01-01

    Active biomonitoring with wet and dry moss bags was used to examine trace element atmospheric deposition in the urban area of Belgrade. The element accumulation capability of Sphagnum girgensohnii Russow was tested in relation to atmospheric bulk deposition. Moss bags were mounted for five 3-month periods (July 2005-October 2006) at three representative urban sites. For the same period monthly bulk atmospheric deposition samples were collected. The concentrations of Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, and Pb were determined by instrumental neutron activation analyses and atomic absorption spectrometry. Significant accumulation of most elements occurred in the exposed moss bags compared with the initial moss content. High correlations between the elements in moss and bulk deposits were found for V, Cu, As, and Ni. The enrichment factors of the elements for both types of monitor followed the same pattern at the corresponding sites. - Accumulated trace elements in the moss Sphagnum girgensohnii reflect atmospheric deposition

  8. Greenhouse gas exchange of rewetted bog peat extraction sites and a Sphagnum cultivation site in northwest Germany

    Science.gov (United States)

    Beyer, C.; Höper, H.

    2015-04-01

    During the last decades an increasing area of drained peatlands has been rewetted. Especially in Germany, rewetting is the principal treatment on cutover sites when peat extraction is finished. The objectives are bog restoration and the reduction of greenhouse gas (GHG) emissions. The first sites were rewetted in the 1980s. Thus, there is a good opportunity to study long-term effects of rewetting on greenhouse gas exchange, which has not been done so far on temperate cutover peatlands. Moreover, Sphagnum cultivating may become a new way to use cutover peatlands and agriculturally used peatlands as it permits the economical use of bogs under wet conditions. The climate impact of such measures has not been studied yet. We conducted a field study on the exchange of carbon dioxide, methane and nitrous oxide at three rewetted sites with a gradient from dry to wet conditions and at a Sphagnum cultivation site in NW Germany over the course of more than 2 years. Gas fluxes were measured using transparent and opaque closed chambers. The ecosystem respiration (CO2) and the net ecosystem exchange (CO2) were modelled at a high temporal resolution. Measured and modelled values fit very well together. Annually cumulated gas flux rates, net ecosystem carbon balances (NECB) and global warming potential (GWP) balances were determined. The annual net ecosystem exchange (CO2) varied strongly at the rewetted sites (from -201.7 ± 126.8 to 29.7± 112.7g CO2-C m-2 a-1) due to differing weather conditions, water levels and vegetation. The Sphagnum cultivation site was a sink of CO2 (-118.8 ± 48.1 and -78.6 ± 39.8 g CO2-C m-2 a-1). The annual CH4 balances ranged between 16.2 ± 2.2 and 24.2 ± 5.0g CH4-C m-2 a-1 at two inundated sites, while one rewetted site with a comparatively low water level and the Sphagnum farming site show CH4 fluxes close to 0. The net N2O fluxes were low and not significantly different between the four sites. The annual NECB was between -185.5 ± 126.9 and 49

  9. Greenhouse gas emissions from rewetted bog peat extraction sites and a Sphagnum cultivation site in Northwest Germany

    Science.gov (United States)

    Beyer, C.; Höper, H.

    2014-03-01

    During the last three decades, an increasing area of drained peatlands was rewetted. This was done with the objective to convert these sites from sources back to sinks or, at least, to much smaller sources of greenhouse gases (GHG). However, available data is still scarce, especially on the long-term climatic effects of rewetting of temperate bogs. Moreover, first field trials are established for Sphagnum cultivating (paludiculture) on wet bog sites and an assessment of the climate impact of such measures has not been studied yet. We conducted a field study on the exchange of carbon dioxide, methane and nitrous oxide at three rewetted sites with a gradient from dry to wet conditions and at a Sphagnum cultivation site in NW Germany over more than two years. Gas fluxes were measured using transparent and opaque closed chambers. The ecosystem respiration (CO2) and the net ecosystem exchange (CO2) were modelled in high time resolution using automatically monitored climate data. Measured and modelled values fit very well together (R2 between 0.88 and 0.98). Annually cumulated gas flux rates, net ecosystem carbon balances (NECB) and global warming potential (GWP) balances were determined. The annual net ecosystem exchange (CO2) varied strongly at the rewetted sites (from -201.7 ± 126.8 to 29.7 ± 112.7 g CO2-C m-2 a-1) due to different weather conditions, water level and vegetation. The Sphagnum cultivation site was a sink of CO2 (-118.8 ± 48.1 and -78.6 ± 39.8 g CO2-C m-2 a-1). The yearly CH4 balances ranged between 16.2 ± 2.2 and 24.2 ± 5.0 g CH4-C m-2 a-1 at two inundated sites, while one rewetted site with a comparatively low water level and the Sphagnum farming site show CH4 fluxes close to zero. The net N2O fluxes were low and not significantly different between the four sites. The annual NECB at the rewetted sites was between -183.8 ± 126.9 and 51.6 ± 112.8 g CO2-C m-2 a-1 and at the Sphagnum cultivating site -114.1 ± 48.1 and -75.3 ± 39.8 g CO2-C m-2 a-1

  10. Potential NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species

    Energy Technology Data Exchange (ETDEWEB)

    Jauhiainen, J. [Joensuu Univ. (Finland). Dept. of Biology; Wallen, B.; Malmer, N. [Lund Univ. (Sweden). Dept. of Plant Ecology

    1996-12-31

    The objective of this research is to test differences in NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species under laboratory conditions. The studied species represent two gradients: the minerotrophy-ombrotrophy (mire margin - mire expanse) gradient, and the hummock-hollow gradient. There are distinct differences in the uptake rate between various Sphagnum species and these differences seem to be due to both structural and environmental factors: (1) on individual basis the highest uptake rate is in species with large capitulum and high number of ion exchange sites i.e. lawn species, (2) on dry mass basis the most effective species are the hummock species though they have a low DM, (3) from the ecosystem point of view, hummock species with high number of shoots per unit area and high uptake rate on dry mass basis, are the most effective species in filtering available nitrogen. (1 ref.)

  11. The potential influence of short-term environmental variability on the composition of testate amoeba communities in Sphagnum peatlands.

    Science.gov (United States)

    Sullivan, Maura E; Booth, Robert K

    2011-07-01

    Testate amoebae are a group of moisture-sensitive, shell-producing protozoa that have been widely used as indicators of changes in mean water-table depth within oligotrophic peatlands. However, short-term environmental variability (i.e., sub-annual) also probably influences community composition. The objective of this study was to assess the potential influence of short-term environmental variability on the composition of testate amoeba communities in Sphagnum-dominated peatlands. Testate amoebae and environmental conditions, including hourly measurements of relative humidity within the upper centimeter of the peatland surface, were examined throughout the 2008 growing season at 72 microsites within 11 peatlands of Pennsylvania and Wisconsin, USA. Relationships among testate amoeba communities, vegetation, depth to water table, pH, and an index of short-term environmental variability (EVI), were examined using nonmetric multidimensional scaling and correlation analysis. Results suggest that EVI influences testate amoeba communities, with some taxa more abundant under highly variable conditions (e.g., Arcella discoides, Difflugia pulex, and Hyalosphenia subflava) and others more abundant when environmental conditions at the peatland surface were relatively stable (e.g., Archerella flavum and Bullinularia indica). The magnitude of environmental variability experienced at the peatland surface appears to be primarily controlled by vegetation composition and density. In particular, sites with dense Sphagnum cover had lower EVI values than sites with loose-growing Sphagnum or vegetation dominated by vascular plants and/or non-Sphagnum bryophytes. Our results suggest that more environmental information may be inferred from testate amoebae than previously recognized. Knowledge of relationships between testate amoebae and short-term environmental variability should lead to more detailed and refined environmental inferences.

  12. Sphagnum-dominated bog systems are highly effective yet variable sources of bio-available iron to marine waters.

    Science.gov (United States)

    Krachler, Regina; Krachler, Rudolf F; Wallner, Gabriele; Steier, Peter; El Abiead, Yasin; Wiesinger, Hubert; Jirsa, Franz; Keppler, Bernhard K

    2016-06-15

    Iron is a micronutrient of particular interest as low levels of iron limit primary production of phytoplankton and carbon fluxes in extended regions of the world's oceans. Sphagnum-peatland runoff is extraordinarily rich in dissolved humic-bound iron. Given that several of the world's largest wetlands are Sphagnum-dominated peatlands, this ecosystem type may serve as one of the major sources of iron to the ocean. Here, we studied five near-coastal creeks in North Scotland using freshwater/seawater mixing experiments of natural creek water and synthetic seawater based on a (59)Fe radiotracer technique combined with isotopic characterization of dissolved organic carbon by Accelerator Mass Spectrometry. Three of the creeks meander through healthy Sphagnum-dominated peat bogs and the two others through modified peatlands which have been subject to artificial drainage for centuries. The results revealed that, at the time of sampling (August 16-24, 2014), the creeks that run through modified peatlands delivered 11-15μg iron per liter creek water to seawater, whereas the creeks that run through intact peatlands delivered 350-470μg iron per liter creek water to seawater. To find out whether this humic-bound iron is bio-available to marine algae, we performed algal growth tests using the unicellular flagellated marine prymnesiophyte Diacronema lutheri and the unicellular marine green alga Chlorella salina, respectively. In both cases, the riverine humic material provided a highly bio-available source of iron to the marine algae. These results add a new item to the list of ecosystem services of Sphagnum-peatlands. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Size matters for violent discharge height and settling speed of Sphagnum spores: important attributes for dispersal potential.

    Science.gov (United States)

    Sundberg, Sebastian

    2010-02-01

    Initial release height and settling speed of diaspores are biologically controlled components which are key to modelling wind dispersal. Most Sphagnum (peat moss) species have explosive spore liberation. In this study, how capsule and spore sizes affect the height to which spores are propelled were measured, and how spore size and spore number of discharged particles relate to settling speed in the aspherical Sphagnum spores. Spore discharge and spore cloud development were filmed in a closed chamber (nine species). Measurements were taken from snapshots at three stages of cloud development. Settling speed of spores (14 species) and clusters were timed in a glass tube. The maximum discharge speed measured was 3.6 m s(-1). Spores reached a maximum height of 20 cm (average: 15 cm) above the capsule. The cloud dimensions at all stages were related positively to capsule size (R(2) = 0.58-0.65). Thus species with large shoots (because they have large capsules) have a dispersal advantage. Half of the spores were released as singles and the rest as clusters (usually two to four spores). Single spores settled at 0.84-1.86 cm s(-1), about 52 % slower than expected for spherical spores with the same diameters. Settling speed displayed a positive curvilinear relationship with spore size, close to predictions by Stokes' law for spherical spores with 68 % of the actual diameters. Light-coloured spores settled slower than dark spores. Settling speed of spore clusters agrees with earlier studies. Effective spore discharge and small, slowly settling spores appear particularly important for species in forested habitats. The spore discharge heights in Sphagnum are among the greatest for small, wind-dispersed propagules. The discharge heights and the slow settling of spores affect dispersal distances positively and may help to explain the wide distribution of most boreal Sphagnum species.

  14. Arquitectura sismo-resistente. Un nuevo enfoque para la solución integral del problema sísmico

    Directory of Open Access Journals (Sweden)

    Giuliani,, Hugo

    1987-02-01

    Full Text Available This work only pretend to state in general terms the reasons, foundations, objectives, action fields, basical principles and compatibilization rules of the Structural Design with the Architectural Design that have allowed us to draw an approach on Seismo-Resistant Architecture and that in the future will allow its study and scientific development.

    El presente trabajo, sólo pretende la formulación en términos generales de las razones, fundamentos, objetivos, campos de acción, principios básicos y pautas de compatibilización del Diseño Estructural con el Diseño Arquitectónico que nos han permitido plantear una Arquitectura Sismo-Resistente y que permitirá en el futuro su profundización y el desarrollo científico de la misma.

  15. Mining for Nonribosomal Peptide Synthetase and Polyketide Synthase Genes Revealed a High Level of Diversity in the Sphagnum Bog Metagenome.

    Science.gov (United States)

    Müller, Christina A; Oberauner-Wappis, Lisa; Peyman, Armin; Amos, Gregory C A; Wellington, Elizabeth M H; Berg, Gabriele

    2015-08-01

    Sphagnum bog ecosystems are among the oldest vegetation forms harboring a specific microbial community and are known to produce an exceptionally wide variety of bioactive substances. Although the Sphagnum metagenome shows a rich secondary metabolism, the genes have not yet been explored. To analyze nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), the diversity of NRPS and PKS genes in Sphagnum-associated metagenomes was investigated by in silico data mining and sequence-based screening (PCR amplification of 9,500 fosmid clones). The in silico Illumina-based metagenomic approach resulted in the identification of 279 NRPSs and 346 PKSs, as well as 40 PKS-NRPS hybrid gene sequences. The occurrence of NRPS sequences was strongly dominated by the members of the Protebacteria phylum, especially by species of the Burkholderia genus, while PKS sequences were mainly affiliated with Actinobacteria. Thirteen novel NRPS-related sequences were identified by PCR amplification screening, displaying amino acid identities of 48% to 91% to annotated sequences of members of the phyla Proteobacteria, Actinobacteria, and Cyanobacteria. Some of the identified metagenomic clones showed the closest similarity to peptide synthases from Burkholderia or Lysobacter, which are emerging bacterial sources of as-yet-undescribed bioactive metabolites. This report highlights the role of the extreme natural ecosystems as a promising source for detection of secondary compounds and enzymes, serving as a source for biotechnological applications. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Climatic modifiers of the response to nitrogen deposition in peat-forming Sphagnum mosses: a meta-analysis.

    Science.gov (United States)

    Limpens, J; Granath, G; Gunnarsson, U; Aerts, R; Bayley, S; Bragazza, L; Bubier, J; Buttler, A; van den Berg, L J L; Francez, A-J; Gerdol, R; Grosvernier, P; Heijmans, M M P D; Hoosbeek, M R; Hotes, S; Ilomets, M; Leith, I; Mitchell, E A D; Moore, T; Nilsson, M B; Nordbakken, J-F; Rochefort, L; Rydin, H; Sheppard, L J; Thormann, M; Wiedermann, M M; Williams, B L; Xu, B

    2011-07-01

    Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain. Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data. We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increased annual precipitation intensified the negative effects of N. The temperature effect was comparable to an experimental application of almost 4 g N m(-2)  yr(-1) for each 1°C increase. Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  17. Sensitivity of spectral indices to CO2 fluxes for several plant communities in a Sphagnum-dominated peatland

    International Nuclear Information System (INIS)

    Letendre, J.; Poulin, M.; Rochefort, L.

    2008-01-01

    A study was conducted in which the relationship between spectral indices and carbon dioxide (CO 2 ) fluxes was tested for different communities in a Sphagnum-dominated peatland. This paper focused on the remote sensing approach that was used to directly link spectral indices to CO 2 fluxes to highlight the potential of remote sensing for mapping the spatial distribution of CO 2 fluxes. Carbon exchange in these ecosystems has become an environmental concern since peatlands play a key role in the global carbon cycle. A portable climate-controlled chamber was used to measure fluxes while simultaneously recording reflectance with a hand-held spectroradiometer. A laboratory experiment was also conducted to find a water-related index that most correlated with Sphagnum water content in order to regulate the normalized difference vegetation index (NDVI) values obtained in the field. The laboratory experiment showed a strong correlation between Sphagnum water content and all spectral indices, notably the water index (WI), normalized difference water index (NDWI), and relative depth index (RDI). The water index was chosen to regulate NDVI values. This paper described the indices that were tested in the field for CO 2 flux estimations. NDVI alone was found to be a poor predictor of net ecosystem exchange. The relationship between CO 2 fluxes and narrow band chlorophyll indices was reasonably well adjusted. It was concluded that the chlorophyll indices may be the most promising for mapping the spatial distribution of CO 2 fluxes in the future. 62 refs., 2 tabs., 4 figs

  18. Capacidad resistente de pilas metálicas tubulares circulares rellenas de hormigón (CFT en puentes integrales

    Directory of Open Access Journals (Sweden)

    Chacón, R.

    2012-09-01

    Full Text Available In this paper, an in-depth analysis of the structural response of concrete-filled tubular structures (CFT is presented. The main objective of the study is to assess the resistance of these structural elements when subjected to lateral displacements. These displacements, together with the corresponding axial forces, represent the actions to which the integral bridges piers are subjected to. For the sake of studying this response, a numerical model is used as a simulation tool over an hypothetical matrix of CFT. These numerical studies together with a wide experimental database found in the literature have been useful for drawing conclusions concerning the cross-sectional capacity of the CFT. A design proposal for this cross-sectional capacity which accounts for confinement is given. This proposal has been compared structurally with the present formulation found in EN1994.

    Se presenta el análisis estructural de pilas metálicas tubulares rellenas de hormigón (CFT sometidas a flexo-compresión. El objetivo principal es valorar los mecanismos resistentes de las pilas cuando se someten a un desplazamiento en cabeza. Estos desplazamientos, conjuntamente con el esfuerzo axil de compresión, que en este trabajo se aproxima con un porcentaje de la resistencia plástica a compresión de los CFT, representan las acciones a las cuales se ven sometidos los elementos de este estudio. Se utiliza una herramienta numérica sobre una base hipotética de prototipos de pilas. Los resultados numéricos obtenidos así como los resultados experimentales encontrados en la literatura han permitido extraer conclusiones relativas a la capacidad seccional de los CFT. Se proponen expresiones de diseño relativas a la capacidad resistente de los CFT considerando el efecto del confinamiento y se comparan con los resultados que se derivan de la formulación de EN1994.

  19. Infecção ou colonização por micro-organismos resistentes: identificação de preditores Infection or colonization with resistant microorganisms: identification of predictors

    Directory of Open Access Journals (Sweden)

    Graciana Maria de Moraes

    2013-01-01

    Full Text Available OBJETIVO: Identificar os fatores preditores de infecção ou colonização por micro-organismos resistentes. MÉTODOS: Foi realizado estudo quantitativo de coorte prospectivo. Foram realizadas a análise descritiva, para conhecimento da população do estudo, e a análise discriminante, para identificação dos fatores preditores. RESULTADOS: Foram incluídos 85 pacientes com infecções por micro-organismos resistentes: Pseudomonas aeruginosas resistente aos carbapenêmicos (24,7%, Acinetobacter resistente aos carbapenêmicos (21,2%, Staphylococcus aureus resistente à meticilina (25,9%, Enterococcus spp. resistente à vancomicina (17,6% e Klebsiella pneumoniae resistente aos carbapenêmicos (10,6%. A análise discriminante identificou transferências de outros hospitais e internação na Unidade de Terapia Intensiva como fatores preditores para ocorrência de infecção pelos grupos S. aureus resistente à meticilina, Acinetobacter resistente aos carbapenêmicos e K. pneumoniae resistente aos carbapenêmicos. Nenhuma das variáveis estudadas foi discriminante para Enterococcus spp. resistente à vancomicina e P. aeruginosas resistente aos carbapenêmico. CONCLUSÃO: Os fatores preditores encontrados foram: internação na UTI e a transferências de outros hospitais.OBJECTIVE: Identifying predictors of infection or colonization with resistant microorganisms. METHODS: A quantitative study of prospective cohort was carried out. A descriptive analysis was performed in order to know the population of the study and a discriminant analysis was performed to identify the predictors. RESULTS: In this study were included 85 patients with infections caused by resistant microorganisms: carbapenem-resistant Pseudomonas aeruginosas (24.7%; carbapenem-resistant Acinetobacter (21.2%; methicillin-resistant Staphylococcus aureus (25.9%, vancomycin-resistant Enterococcus spp (17.6% and carbapenem-resistant Klebsiella pneumonia (10.6%. The discriminant analysis

  20. Assessing environmental attributes and effects of climate change on Sphagnum peatland distributions in North America using single- and multi-species models.

    Science.gov (United States)

    Oke, Tobi A; Hager, Heather A

    2017-01-01

    The fate of Northern peatlands under climate change is important because of their contribution to global carbon (C) storage. Peatlands are maintained via greater plant productivity (especially of Sphagnum species) than decomposition, and the processes involved are strongly mediated by climate. Although some studies predict that warming will relax constraints on decomposition, leading to decreased C sequestration, others predict increases in productivity and thus increases in C sequestration. We explored the lack of congruence between these predictions using single-species and integrated species distribution models as proxies for understanding the environmental correlates of North American Sphagnum peatland occurrence and how projected changes to the environment might influence these peatlands under climate change. Using Maximum entropy and BIOMOD modelling platforms, we generated single and integrated species distribution models for four common Sphagnum species in North America under current climate and a 2050 climate scenario projected by three general circulation models. We evaluated the environmental correlates of the models and explored the disparities in niche breadth, niche overlap, and climate suitability among current and future models. The models consistently show that Sphagnum peatland distribution is influenced by the balance between soil moisture deficit and temperature of the driest quarter-year. The models identify the east and west coasts of North America as the core climate space for Sphagnum peatland distribution. The models show that, at least in the immediate future, the area of suitable climate for Sphagnum peatland could expand. This result suggests that projected warming would be balanced effectively by the anticipated increase in precipitation, which would increase Sphagnum productivity.

  1. Molybdenum-based diazotrophy in a Sphagnum peatland in northern Minnesota.

    Science.gov (United States)

    Warren, Melissa J; Lin, Xueju; Gaby, John C; Kretz, Cecilia B; Kolton, Max; Morton, Peter L; Pett-Ridge, Jennifer; Weston, David J; Schadt, Christopher W; Kostka, Joel E; Glass, Jennifer B

    2017-06-30

    Microbial N 2 fixation (diazotrophy) represents an important nitrogen source to oligotrophic peatland ecosystems, which are important sinks for atmospheric CO 2 and susceptible to changing climate. The objectives of this study were: (i) to determine the active microbial group and type of nitrogenase mediating diazotrophy in a ombrotrophic Sphagnum -dominated peat bog (the S1 peat bog, Marcell Experimental Forest, Minnesota, USA); and (ii) to determine the effect of environmental parameters (light, O 2 , CO 2 , CH 4 ) on potential rates of diazotrophy measured by acetylene (C 2 H 2 ) reduction and 15 N 2 incorporation. Molecular analysis of metabolically active microbial communities suggested that diazotrophy in surface peat was primarily mediated by Alphaproteobacteria ( Bradyrhizobiaceae and Beijerinckiaceae ). Despite higher dissolved vanadium (V; 11 nM) than molybdenum (Mo; 3 nM) in surface peat, a combination of metagenomic, amplicon sequencing and activity measurements indicated that Mo-containing nitrogenases dominate over the V-containing form. Acetylene reduction was only detected in surface peat exposed to light, with the highest rates observed in peat collected from hollows with the highest water content. Incorporation of 15 N 2 was suppressed 90% by O 2 and 55% by C 2 H 2 , and was unaffected by CH 4 and CO 2 amendments. These results suggest that peatland diazotrophy is mediated by a combination of C 2 H 2 -sensitive and C 2 H 2 -insensitive microbes that are more active at low O 2 and show similar activity at high and low CH 4 Importance Previous studies indicate that diazotrophy provides an important nitrogen source and is linked to methanotrophy in Sphagnum -dominated peatlands. However, the environmental controls and enzymatic pathways of peatland diazotrophy, as well as the metabolically active microbial populations that catalyze this process remain in question. Our findings indicate that oxygen levels and photosynthetic activity override low

  2. Modelling hydrological processes and dissolved organic carbon dynamics in a rehabilitated Sphagnum-dominated peatland

    Science.gov (United States)

    Bernard-Jannin, Léonard; Binet, Stéphane; Gogo, Sébastien; Leroy, Fabien; Perdereau, Laurent; Laggoun-Défarge, Fatima

    2017-04-01

    Sphagnum-dominated peatlands represent a global major stock of carbon (C). Dissolved organic carbon (DOC) exports through runoff and leaching could reduce their potential C sink function and impact downstream water quality. DOC production in peatlands is strongly controlled by the hydrology, especially water table depth (WTD). Therefore, disturbances such as drainage can lead to increase DOC exports by lowering the WTD. Hydrological restoration (e.g. rewetting) can be undertaken to restore peatland functioning with an impact on DOC exports. The objective of this study is to assess the impact of drainage and rewetting on hydrological processes and their interactions with DOC dynamics in a Sphagnum dominated peatland. A hydrological model has been applied to a drained peatland (La Guette, France) which experienced a rewetting action on February 2014 and where WTD has been recorded in four piezometers at a 15 min time step since 2009. In addition, DOC concentrations in the peatland have been measured 6 times a year since 2014. The hydrological model is a WTD dependent reservoir model composed by two reservoirs representing the micro and macro porosity of the peatland (Binet et al., 2013). A DOC production module in both reservoirs was implemented based on temperature and WTD. The model was calibrated against WTD and DOC concentrations for each piezometer. The results show that the WTD in the study area is strongly affected by local meteorological conditions that could hide the effect of the rewetting action. The preliminary results evidenced that an additional source of water, identified as groundwater supply originating from the surrounding sandy layer aquifer, is necessary to maintain the water balance, especially during wet years (NS>0.8). Finally, the DOC module was able to describe DOC concentrations measured in the peatland and could be used to assess the impact of rewetting on DOC dynamics at different locations and to identify the factors of control of DOC

  3. Acrotelm pedogenesis of a Sphagnum bog is reflected in effective unsaturated hydraulic properties

    Science.gov (United States)

    Weber, Tobias K. D.; Iden, Sascha C.; Durner, Wolfgang

    2017-04-01

    In ombrotrophic peatlands, the moisture content of the vadose zone (acrotelm) controls oxygen diffusion rates, redox state, and the turnover of organic matter. Whether peatlands act as sinks or sources of atmospheric carbon thus relies on variably saturated flow processes. Modeling of these processes is crucial in assessing effects of changed environmental conditions on the future development of these ecosystems. The Richards equation (RE) is the standard model for water flow in soils, but it is not clear whether it can be applied to simulate water flow in live Sphagnum moss. To check the suitability of the RE to describe the water dynamics in drying moss and peat we conducted transient laboratory evaporation experiments on undisturbed samples from the entire acrotelm. The experimental data consisted of measured pressure heads in two depths and water fluxes, and were evaluated by inverse modelling using the RE as process model. The results showed that the measurements could be matched very well only if the soil hydraulic properties (SHPs) were represented by a suitable model. A successful parameterisation of the SHPs of the moss was based on pore-size distributions (PSD) which combine three distinct pore systems of the Sphagnum moss, reflecting an inter-, intra-, and inner-plant pore space. We had to extend the traditional van Genuchten-Mualem model to account for non-capillary water storage and flow to obtain consistent descriptions of the observations. For the deeper samples, the pedogenesis of the acrotelm, a process of compaction and biochemical degradation of the solid matrix, had considerably impact on the shape of the SHPs. The collapse of the inter-plant pores and their filling with smaller particles led gradually to bi-modal PSDs with increasing depth. This coincides with a homogenisation and a considerably reduction in horizontal variability of SHPs at greater depths. We conclude that the RE with adequate representation of SHPs is a valid process

  4. Effect of Water Content Components on Desiccation and Recovery in Sphagnum Mosses

    Science.gov (United States)

    Hájek, Tomáš; Beckett, Richard P.

    2008-01-01

    Background and Aims The basic parameters of water relations were measured in Sphagnum mosses. The relationships of these parameters to the photosynthetic response to desiccation and the ecology of these mosses were then tested. Methods The water relations parameters of six Sphagnum species (mosses typical of wet habitats) and Atrichum androgynum (a moss more typical of mesophytic conditions) were calculated from pressure–volume isotherms. Photosynthetic properties during and after moderate desiccation were monitored by chlorophyll fluorescence. Key Results When desiccated, the hummock-forming species S. fuscum and S. magellanicum lost more water before turgor started dropping than other sphagna inhabiting less exposed habitats (73 % compared with 56 % on average). Osmotic potentials at full turgor were similar in all species, with an average value of −1·1 MPa. Hummock sphagna had clearly more rigid cell walls than species of wet habitats (ε = 3·55 compared with 1·93 MPa). As a result, their chlorophyllous cells lost turgor at higher relative water contents (RWCs) than species of wet habitats (0·61 compared with 0·46) and at less negative osmotic potentials (–2·28 compared with −3·00 MPa). During drying, ΦPSII started declining earlier in hummock species (at an RWC of 0·65 compared with 0·44), and Fv/Fm behaved similarly. Compared with other species, hummock sphagna desiccated to −20 or −40 MPa recovered more completely after rehydration. Atrichum androgynum responded to desiccation similarly to hummock sphagna, suggesting that their desiccation tolerance may have a similar physiological basis. Conclusions Assuming a fixed rate of desiccation, the higher water-holding capacities of hummock sphagna will allow them to continue metabolism for longer than other species. While this could be viewed as a form of ‘desiccation avoidance’, hummock species also recover faster than other species during rehydration, suggesting that they have higher

  5. The effect of Sphagnum farming on the greenhouse gas balance of donor and propagation areas, irrigation polders and commercial cultivation sites

    Science.gov (United States)

    Oestmann, Jan; Tiemeyer, Bärbel

    2017-04-01

    Drainage of peatlands for agriculture, forestry and peat extraction turned these landscapes into hotspots of greenhouse gas emissions. Climate protection now fosters rewetting projects to restore the natural peatland function as a sink of atmospheric carbon. One possible way to combine ecological and economical goals is Sphagnum farming, i.e. the cultivation of Sphagnum mosses as high-quality substrates for horticulture. This project scientifically evaluates the attempt of commercial Sphagnum farming on former peat extraction sites in north-western Germany. The exchange of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) of the whole peatland-based production chain comprising a donor mire, a propagation area, an irrigation polder and a cultivation site will be determined in a high temporal resolution for two years using manual chambers. This will allow evaluating the greenhouse gas balance of Sphagnum farming sites in comparison to near-natural sites and the potential of Sphagnum farming for restoring drained peatlands to sinks of atmospheric carbon. The influence of different irrigation techniques will also be tested. Additionally, selected plots will be equipped with open top chambers in order to examine the greenhouse gas exchange under potential future climate change conditions. Finally, a 13C pulse labeling experiment will make it possible to trace the newly sequestered CO2 in biomass, soil, respiration and dissolved organic carbon.

  6. Development of a Waste Water Regenerative System - Using Sphagnum Moss Ion-exchange

    Science.gov (United States)

    McKeon, M.; Wheeler, R.; Leahy, Jj

    The use of inexpensive, light weight and regenerative systems in an enclosed environment is of great importance to sustained existence in such habitats as the International Space Station, Moon or even Mars. Many systems exist which utilise various synthetic ion exchangers to complete the process of waste water clean-up. These systems do have a very good exchange rate for cations but a very low exchange rate for anions. They also have a maximum capacity before they need regeneration. This research proposes a natural alternative to these synthetic ion-exchangers that utilises one of natures greatest ion-exchangers, that of Sphagnum Moss. Sphagna can be predominantly found in the nutrient poor environment of Raised Bogs, a type of isolated wetland with characteristic low pH and little interaction with the surrounding water table. All nutrients come from precipitation. The sphagna have developed as the bog's sponges, soaking up all available nutrients (both cation & anion) from the precipitation and eventually distributing them to the surrounding flora and fauna, through the water. The goal of this research is to use this ability in the processing of waste water from systems similar to isolated microgravity environments, to produce clean water for reuse in these environments. The nutrients taken up by the sphagna will also be utilised as a growth medium for cultivar growth, such as those selected for hydroponics' systems.

  7. The narrow endemic Norwegian peat moss Sphagnum troendelagicum originated before the last glacial maximum.

    Science.gov (United States)

    Stenøien, H K; Shaw, A J; Stengrundet, K; Flatberg, K I

    2011-02-01

    It is commonly found that individual hybrid, polyploid species originate recurrently and that many polyploid species originated relatively recently. It has been previously hypothesized that the extremely rare allopolyploid peat moss Sphagnum troendelagicum has originated multiple times, possibly after the last glacial maximum in Scandinavia. This conclusion was based on low linkage disequilibrium in anonymous genetic markers within natural populations, in which sexual reproduction has never been observed. Here we employ microsatellite markers and chloroplast DNA (cpDNA)-encoded trnG sequence data to test hypotheses concerning the origin and evolution of this species. We find that S. tenellum is the maternal progenitor and S. balticum is the paternal progenitor of S. troendelagicum. Using various Bayesian approaches, we estimate that S. troendelagicum originated before the Holocene but not before c. 80,000 years ago (median expected time since speciation 40 000 years before present). The observed lack of complete linkage disequilibrium in the genome of this species suggests cryptic sexual reproduction and recombination. Several lines of evidence suggest multiple origins for S. troendelagicum, but a single origin is supported by approximate Bayesian computation analyses. We hypothesize that S. troendelagicum originated in a peat-dominated refugium before last glacial maximum, and subsequently immigrated to central Norway by means of spore flow during the last thousands of years.

  8. Peatland succession induces a shift in the community composition of Sphagnum-associated active methanotrophs.

    Science.gov (United States)

    Putkinen, Anuliina; Larmola, Tuula; Tuomivirta, Tero; Siljanen, Henri M P; Bodrossy, Levente; Tuittila, Eeva-Stiina; Fritze, Hannu

    2014-06-01

    Sphagnum-associated methanotrophs (SAM) are an important sink for the methane (CH4) formed in boreal peatlands. We aimed to reveal how peatland succession, which entails a directional change in several environmental variables, affects SAM and their activity. Based on the pmoA microarray results, SAM community structure changes when a peatland develops from a minerotrophic fen to an ombrotrophic bog. Methanotroph subtypes Ia, Ib, and II showed slightly contrasting patterns during succession, suggesting differences in their ecological niche adaptation. Although the direct DNA-based analysis revealed a high diversity of type Ib and II methanotrophs throughout the studied peatland chronosequence, stable isotope probing (SIP) of the pmoA gene indicated they were active mainly during the later stages of succession. In contrast, type Ia methanotrophs showed active CH4 consumption in all analyzed samples. SIP-derived (13)C-labeled 16S rRNA gene clone libraries revealed a high diversity of SAM in every succession stage including some putative Methylocella/Methyloferula methanotrophs that are not detectable with the pmoA-based approach. In addition, a high diversity of 16S rRNA gene sequences likely representing cross-labeled nonmethanotrophs was discovered, including a significant proportion of Verrucomicrobia-related sequences. These results help to predict the effects of changing environmental conditions on SAM communities and activity. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  9. Lateral extension in Sphagnum mires along the southern margin of the boreal region, Western Siberia

    International Nuclear Information System (INIS)

    Peregon, A; Uchida, M; Yamagata, Y

    2009-01-01

    Although recent studies have recognized Northern Eurasian ecosystems as an important carbon reservoir, little is known about the forest-peatland interactions in a boreal environment induced by ongoing climatic changes. This study focuses on the evaluation of both the long-term and contemporary trends of land-cover changes and rates of lateral extension of peat-accumulating wetlands toward the adjacent forests, estimated at the southern climatic range of the Sphagnum-dominated mires in Western Siberia. We used the radiocarbon dates and stratigraphy of peat sediments from seven peat cores, analyzed at two types of forest-peatland ecotones, which are located close to each other but differ by topography and composition of their plant communities. The rate of lateral extension was found in a wide range varying from 2.3 to 791.7 cm yr -1 . It was observed to be rapid during the initial stage of mire development, but to have slowed down over the last 2000-3000 yr. Our results, therefore, strongly contradict the concept of progressive peat accumulation throughout the late Holocene and contribute to our knowledge about ongoing land-cover change in the natural ecosystems of the Northern hemisphere.

  10. Abiotic reaction of iodate with sphagnum peat and other natural organic matter

    International Nuclear Information System (INIS)

    Steinberg, S.M.; Kimble, G.; Schmett, G.T.; Emerson, D.W.; Turner, M.F.; Rudin, M.

    2008-01-01

    Previous studies have shown that iodine (including 129 I) can be strongly retained in organic-rich surface soils and sediment and that a large fraction of soluble iodine may be associated with dissolved humic material. Iodate (IO 3 - ) reacts with natural organic matter (NOM) producing either hypoiodous acid (HIO) or I 2 as an intermediate. This intermediate is subsequently incorporated into the organic matter. Based on reactions of model compounds, we infer that iodine reacts with peat by aromatic substitution of hydrogen on phenolic constituents of the peat. Alternatively, the intermediate, HIO or I 2 , may be reduced to iodide (I - ). The pH (and temperature) dependence of the IO 3 - reaction (reduction) has been explored with sphagnum peat, alkali lignin, and several model compounds. The incorporation of iodine into NOM has been verified by pyrolysis gas chromatography/mass spectrometry (GC/MS). Model compound studies indicate that reduction of IO 3 - to HIO may result from reaction with hydroquinone (or semiquinone) moieties of the peat. (author)

  11. Mycobacterium minnesotense sp. nov., a photochromogenic bacterium isolated from sphagnum peat bogs.

    Science.gov (United States)

    Hannigan, Geoffrey D; Krivogorsky, Bogdana; Fordice, Daniel; Welch, Jacqueline B; Dahl, John L

    2013-01-01

    Several intermediate-growing, photochromogenic bacteria were isolated from sphagnum peat bogs in northern Minnesota, USA. Acid-fast staining and 16S rRNA gene sequence analysis placed these environmental isolates in the genus Mycobacterium, and colony morphologies and PCR restriction analysis patterns of the isolates were similar. Partial sequences of hsp65 and dnaJ1 from these isolates showed that Mycobacterium arupense ATCC BAA-1242(T) was the closest mycobacterial relative, and common biochemical characteristics and antibiotic susceptibilities existed between the isolates and M. arupense ATCC BAA-1242(T). However, compared to nonchromogenic M. arupense ATCC BAA-1242(T), the environmental isolates were photochromogenic, had a different mycolic acid profile and had reduced cell-surface hydrophobicity in liquid culture. The data reported here support the conclusion that the isolates are representatives of a novel mycobacterial species, for which the name Mycobacterium minnesotense sp. nov. is proposed. The type strain is DL49(T) (=DSM 45633(T) = JCM 17932(T) = NCCB 100399(T)).

  12. Origin and diversity of testate amoebae shell composition: Example of Bullinularia indica living in Sphagnum capillifolium.

    Science.gov (United States)

    Delaine, Maxence; Bernard, Nadine; Gilbert, Daniel; Recourt, Philippe; Armynot du Châtelet, Eric

    2017-06-01

    Testate amoebae are free-living shelled protists that build a wide range of shells with various sizes, shapes, and compositions. Recent studies showed that xenosomic testate amoebae shells could be indicators of atmospheric particulate matter (PM) deposition. However, no study has yet been conducted to assess the intra-specific mineral, organic, and biologic grain diversity of a single xenosomic species in a natural undisturbed environment. This study aims at providing new information about grain selection to develop the potential use of xenosomic testate amoebae shells as bioindicators of the multiple-origin mineral/organic diversity of their proximal environment. To fulfil these objectives, we analysed the shell content of 38 Bullinularia indica individuals, a single xenosomic testate amoeba species living in Sphagnum capillifolium, by scanning electron microscope (SEM) coupled with X-ray spectroscopy. The shells exhibited high diversities of mineral, organic, and biomineral grains, which confirms their capability to recycle xenosomes. Mineral grain diversity and size of B. indica matched those of the atmospheric natural mineral PM deposited in the peatbog. Calculation of grain size sorting revealed a discrete selection of grains agglutinated by B. indica. These results are a first step towards understanding the mechanisms of particle selection by xenosomic testate amoebae in natural conditions. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. The narrow endemic Norwegian peat moss Sphagnum troendelagicum originated before the last glacial maximum

    Science.gov (United States)

    Stenøien, H K; Shaw, A J; Stengrundet, K; Flatberg, K I

    2011-01-01

    It is commonly found that individual hybrid, polyploid species originate recurrently and that many polyploid species originated relatively recently. It has been previously hypothesized that the extremely rare allopolyploid peat moss Sphagnum troendelagicum has originated multiple times, possibly after the last glacial maximum in Scandinavia. This conclusion was based on low linkage disequilibrium in anonymous genetic markers within natural populations, in which sexual reproduction has never been observed. Here we employ microsatellite markers and chloroplast DNA (cpDNA)-encoded trnG sequence data to test hypotheses concerning the origin and evolution of this species. We find that S. tenellum is the maternal progenitor and S. balticum is the paternal progenitor of S. troendelagicum. Using various Bayesian approaches, we estimate that S. troendelagicum originated before the Holocene but not before c. 80 000 years ago (median expected time since speciation 40 000 years before present). The observed lack of complete linkage disequilibrium in the genome of this species suggests cryptic sexual reproduction and recombination. Several lines of evidence suggest multiple origins for S. troendelagicum, but a single origin is supported by approximate Bayesian computation analyses. We hypothesize that S. troendelagicum originated in a peat-dominated refugium before last glacial maximum, and subsequently immigrated to central Norway by means of spore flow during the last thousands of years. PMID:20717162

  14. Lateral extension in Sphagnum mires along the southern margin of the boreal region, Western Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Peregon, A; Uchida, M; Yamagata, Y, E-mail: anna.peregon@nies.go.j [Center for Global Environmental Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2009-10-15

    Although recent studies have recognized Northern Eurasian ecosystems as an important carbon reservoir, little is known about the forest-peatland interactions in a boreal environment induced by ongoing climatic changes. This study focuses on the evaluation of both the long-term and contemporary trends of land-cover changes and rates of lateral extension of peat-accumulating wetlands toward the adjacent forests, estimated at the southern climatic range of the Sphagnum-dominated mires in Western Siberia. We used the radiocarbon dates and stratigraphy of peat sediments from seven peat cores, analyzed at two types of forest-peatland ecotones, which are located close to each other but differ by topography and composition of their plant communities. The rate of lateral extension was found in a wide range varying from 2.3 to 791.7 cm yr{sup -1}. It was observed to be rapid during the initial stage of mire development, but to have slowed down over the last 2000-3000 yr. Our results, therefore, strongly contradict the concept of progressive peat accumulation throughout the late Holocene and contribute to our knowledge about ongoing land-cover change in the natural ecosystems of the Northern hemisphere.

  15. Chromobacterium sphagni sp. nov., an insecticidal bacterium isolated from Sphagnum bogs.

    Science.gov (United States)

    Blackburn, Michael B; Farrar, Robert R; Sparks, Michael E; Kuhar, Daniel; Mitchell, Ashaki; Gundersen-Rindal, Dawn E

    2017-09-01

    Sixteen isolates of Gram-reaction-negative, motile, violet-pigmented bacteria were isolated from Sphagnum bogs in West Virginia and Maine, USA. 16S rRNA gene sequences and fatty acid analysis revealed a high degree of relatedness among the isolates, and genome sequencing of two isolates, IIBBL 14B-1T and IIBBL 37-2 (from West Virginia and Maine, respectively), revealed highly similar genomic sequences. The average nucleotide identity (gANI) calculated for these two isolates was found to be in excess of 99 %, but did not exceed 88 % when comparing either isolate with genomic sequences of Chromobacterium violaceum ATCC 12472T, C. haemolyticum DSM 19808T, C. piscinae ND17, C. subtsugae PRAA4-1T, C. vaccinii MWU205T or C. amazonense CBMAI 310T. Collectively, gANI and 16S rRNA gene sequence comparisons suggested that isolates IIBBL 14B-1T and IIBBL 37-2 were most closely related to C. subtsugae, but represented a distinct species. We propose the name Chromobacterium sphagni sp. nov. for this taxon; the type strain is IIBBL 14B-1T (=NRRL B-67130T=JCM 31882T).

  16. Abundance, diversity and depth distribution of Planctomycetes in northern Sphagnum-dominated wetlands

    Directory of Open Access Journals (Sweden)

    Svetlana N. Dedysh

    2012-01-01

    Full Text Available Members of the bacterial phylum Planctomycetes inhabit various aquatic and terrestrial environments. In this study, fluorescence in situ hybridization (FISH was applied to assess the abundance and depth distribution of these bacteria in nine different Sphagnum-dominated wetlands of Northern Russia. Planctomycetes were most abundant in the oxic part of peat bog profiles. The respective cell numbers were in the range 1.1-6.7×107 cells per gram of wet peat, comprising 2 to 14% of total bacterial cells and displaying linear correlation to the peat water pH. Most peatland sites showed a sharp decline of planctomycete abundance with depth, while in two particular sites this decline was followed by a second population maximum in an anoxic part of the bog profile. Oxic peat layers were dominated by representatives of the Isosphaera-Singulisphaera group, while anoxic part of the bog profile was inhabited mostly by Zavarzinella- and Pirellula-like planctomycetes. Phylogenetically related bacteria of the candidate division OP3 were detected in both oxic and anoxic peat with cell densities of 0.6-4.6×106 cells per gram of wet peat.

  17. Denervação Renal com Cateter Irrigado em Hipertensos Resistentes: Uma Estratégia Promissora?

    Directory of Open Access Journals (Sweden)

    Luciana Armaganijan

    2014-04-01

    Full Text Available Fundamento: A hipertensão arterial sistêmica constitui importante problema de saúde pública e significativa causa de mortalidade cardiovascular. A elevada prevalência e as reduzidas taxas de controle tensional despertaram o interesse por estratégias terapêuticas alternativas. A denervação simpática renal percutânea surgiu como perspectiva no tratamento de hipertensos resistentes. Objetivo: Avaliar a factibilidade e a segurança da denervação renal com cateter irrigado. Métodos: Dez hipertensos resistentes foram submetidos ao procedimento. O desfecho primário foi a segurança, avaliada por eventos adversos periprocedimento, função renal e anormalidade vascular renal aos 6 meses. Os desfechos secundários constituíram mudanças na pressão arterial (consultório e monitorização ambulatorial e no número de anti-hipertensivos aos 6 meses. Resultados: A média de idade foi de 47,3 (± 12 anos, 90% eram mulheres. No primeiro caso, houve dissecção de artéria renal causada por trauma da bainha, fato que não se repetiu após ajuste técnico, demonstrando efeito da curva de aprendizado. Nenhum caso de trombose/infarto renal ou óbito foi reportado. Não se observou elevação dos níveis séricos de creatinina durante o seguimento. Aos 6 meses, diagnosticou-se um caso de estenose significativa de artéria renal, sem repercussão clínica. A denervação renal reduziu a pressão arterial de consultório, em média, em 14,6/6,6 mmHg (p = 0,4 tanto para pressão arterial sistólica como para a diastólica. A redução média da pressão arterial pela monitorização ambulatorial foi de 28/17,6 mmHg (p = 0,02 e p = 0,07 para pressão arterial sistólica e diastólica, respectivamente. Houve redução média de 2,1 anti-hipertensivos. Conclusão: A denervação renal é factível e segura no tratamento da hipertensão arterial sistêmica resistente. Estudos maiores são necessários para confirmar nossos resultados.

  18. Variabilidade isoenzimática entre linhagens de amendoim resistentes à seca Isoenzimatic variability between peanut lines resistant to drought

    Directory of Open Access Journals (Sweden)

    Roseane Cavalcanti dos Santos

    2000-04-01

    Full Text Available O uso da técnica de eletroforese para separar múltiplas formas moleculares de enzimas tem sido bastante explorada na área biológica, cujas diferenças detectadas nos tecidos podem ser eficientemente usadas para diferenciação de cultivares em qualquer fase de seu desenvolvimento fenológico. Nesse trabalho, procedeu-se ao estudo da variabilidade isoenzimática em seis linhagens de amendoim resistentes à seca, com o objetivo de se verificar as possíveis relações da variação encontrada na base desses descritores com essa aptidão no amendoim. Estudaram-se folíolos da parte apical com 5 dias após a germinação, utilizando-se a técnica de eletroforese em gel de poliacrilamida (7% sistema horizontal e contínuo de tampão. Os sistemas estudados foram fosfatase ácida (ACP, malato desidrogenase (MDH, leucina aminopeptidase (LAP, peroxidase (PO, e esterase (EST. A caracterização fenotípica dos genótipos permitiu a separação de quatro grupos para ACP, três para LAP, dois para MDH e seis para PO e EST. A partir da análise dos componentes principais dos grupos obtidos, observou-se que a cultivar IAC Tupã (sensível à seca foi separada das demais, especialmente da cultivar resistente Senegal 55437.The use of electrophoretic techniques to separate multiple molecular forms of enzymes has been used in the biological science, where differences in isozymes among tissues can be used efficiently on cultivar differentiation during any life cycle phase. In this paper, the variability of six drought resistant peanut lines was studied by isozymes analysis aiming to verify the possible relations between enzymatic descriptors and drought resistance character. Leaflets were analyzed by horizontal poliacrylamide gel electrophoresis technique and buffer continuos systems for the following systems: acid phosphatase (ACP, malate dehydrogenase (MDH, leucine aminopeptidase (LAP, peroxidase (POX and esterase (EST. The phenotypic characterization of the

  19. Prevalencia de Staphylococcus aureus resistente a meticilina en infecciones de piel y partes blandas en pacientes ambulatorios

    Directory of Open Access Journals (Sweden)

    Verónica Bermejo

    2012-08-01

    Full Text Available Recientemente se ha observado un aumento en la prevalencia de Staphylococcus aureus resistente a la meticilina (SAMR en pacientes ambulatorios con infecciones de piel y partes blandas (IPyPB. Los datos epidemiológicos locales disponibles son limitados. Se realizó un estudio descriptivo, prospectivo, de consultantes con IPyPB en la División Infectología del Hospital General de Agudos Juan A. Fernández, en el período 01/10/2009 a 31/01/2011. Fueron 130; edad mediana 36 años (RIC 25.9-43.5; hombres 61.5%. El 46.9% era HIV+. Cien cultivos (76.9%, de 100 pacientes, resultaron positivos: 83 S. aureus, 8 Streptococcus spp. y 9 con otros microorganismos. De los S. aureus aislados, 62 (74.7% fueron resistentes a oxacilina, 12 (14.4% a clindamicina, 14 (16.9% a eritromicina, 5 (6% a ciprofloxacina, presentando en algunos casos más de una resistencia. Todos fueron sensibles a rifampicina y minociclina, y 98.8% (82 a trimetoprima-sulfametoxazol. El 83.8% (52 de los pacientes con SAMR tenían algún factor de riesgo (FR, sin diferencias con los pacientes con otros aislamientos. La presentación clínica más frecuente de IPyPB / SAMR fue forunculosis: 56.4 (35/62 vs. 28.9% (11/38 en infecciones por otros microorganismos (p = 0.013. La resistencia a oxacilina fue similar entre pacientes HIV+ y negativos (79.1 vs. 70%, p = 0.179 (34/43 vs. 28/40. Concluimos que en la población estudiada se encontró una alta prevalencia de SAMR, independientemente de la serología para HIV o la presencia de FR. Las opciones de tratamiento empírico para este microorganismo son minociclina y trimetoprima-sulfametoxazol.

  20. Sepse por Staphylococus aureus resistente à meticilina adquirida na comunidade no sul do Brasil Sepsis due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil

    Directory of Open Access Journals (Sweden)

    Luciane Cristina Gelatti

    2009-08-01

    Full Text Available Staphylococcus aureus resistente à meticilina foi inicialmente descrito como um típico microrganismo adquirido em infecções nosocomiais. No entanto, nos últimos anos Staphylococcus aureus resistente à meticilina adquirido na comunidade é causa de infecções de pele e tecidos moles, mas infecções graves como pneumonia e sepse podem ocorrer. Este relato descreve um caso de sepse em criança, complicado com pneumonia secundária a lesão em partes moles por Staphylococcus aureus resistente à meticilina adquirido na comunidade no Sul do Brasil. O paciente foi atendido em Unidade de Emergência com história de ferimento provocado por trauma em membro inferior que evoluiu para celulite, pneumonia e sepse.Methicillin-resistant Staphylococcus aureus was initially described as a typical microorganism acquired in nosocomial infections. However, over recent years, community-acquired methicillin-resistant Staphylococcus aureus has been a cause of skin and soft-tissue infections. Serious infections such as pneumonia and sepsis can also occur. This report describes a case of sepsis in a child that was complicated by pneumonia secondary to soft tissue lesions that were due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil. The patient was attended at the Emergency Unit with a history of injury caused by lower-limb trauma that evolved to cellulitis, pneumonia and sepsis.

  1. Sensitivity of spectral indices to CO{sub 2} fluxes for several plant communities in a Sphagnum-dominated peatland

    Energy Technology Data Exchange (ETDEWEB)

    Letendre, J.; Poulin, M.; Rochefort, L. [Laval Univ., Quebec City, PQ (Canada). Dept. de Phytologie, Peatland Ecology and Research Group

    2008-07-01

    A study was conducted in which the relationship between spectral indices and carbon dioxide (CO{sub 2}) fluxes was tested for different communities in a Sphagnum-dominated peatland. This paper focused on the remote sensing approach that was used to directly link spectral indices to CO{sub 2} fluxes to highlight the potential of remote sensing for mapping the spatial distribution of CO{sub 2} fluxes. Carbon exchange in these ecosystems has become an environmental concern since peatlands play a key role in the global carbon cycle. A portable climate-controlled chamber was used to measure fluxes while simultaneously recording reflectance with a hand-held spectroradiometer. A laboratory experiment was also conducted to find a water-related index that most correlated with Sphagnum water content in order to regulate the normalized difference vegetation index (NDVI) values obtained in the field. The laboratory experiment showed a strong correlation between Sphagnum water content and all spectral indices, notably the water index (WI), normalized difference water index (NDWI), and relative depth index (RDI). The water index was chosen to regulate NDVI values. This paper described the indices that were tested in the field for CO{sub 2} flux estimations. NDVI alone was found to be a poor predictor of net ecosystem exchange. The relationship between CO{sub 2} fluxes and narrow band chlorophyll indices was reasonably well adjusted. It was concluded that the chlorophyll indices may be the most promising for mapping the spatial distribution of CO{sub 2} fluxes in the future. 62 refs., 2 tabs., 4 figs.

  2. Sphagnum-dominated bog systems are highly effective yet variable sources of bio-available iron to marine waters

    International Nuclear Information System (INIS)

    Krachler, Regina; Krachler, Rudolf F.; Wallner, Gabriele; Steier, Peter; El Abiead, Yasin; Wiesinger, Hubert; Jirsa, Franz; Keppler, Bernhard K.

    2016-01-01

    Iron is a micronutrient of particular interest as low levels of iron limit primary production of phytoplankton and carbon fluxes in extended regions of the world's oceans. Sphagnum-peatland runoff is extraordinarily rich in dissolved humic-bound iron. Given that several of the world's largest wetlands are Sphagnum-dominated peatlands, this ecosystem type may serve as one of the major sources of iron to the ocean. Here, we studied five near-coastal creeks in North Scotland using freshwater/seawater mixing experiments of natural creek water and synthetic seawater based on a "5"9Fe radiotracer technique combined with isotopic characterization of dissolved organic carbon by Accelerator Mass Spectrometry. Three of the creeks meander through healthy Sphagnum-dominated peat bogs and the two others through modified peatlands which have been subject to artificial drainage for centuries. The results revealed that, at the time of sampling (August 16–24, 2014), the creeks that run through modified peatlands delivered 11–15 μg iron per liter creek water to seawater, whereas the creeks that run through intact peatlands delivered 350–470 μg iron per liter creek water to seawater. To find out whether this humic-bound iron is bio-available to marine algae, we performed algal growth tests using the unicellular flagellated marine prymnesiophyte Diacronema lutheri and the unicellular marine green alga Chlorella salina, respectively. In both cases, the riverine humic material provided a highly bio-available source of iron to the marine algae. These results add a new item to the list of ecosystem services of Sphagnum-peatlands. - Highlights: • We report that peat-bogs are sources of bio-available iron to marine algae. • This iron is effectively chelated with aquatic humic acids. • The radiocarbon age of the iron-carrying aquatic humic acids was up to 550 years. • Analysis was focused on mixing experiments of iron-rich creek water with seawater. • Drained peatlands with

  3. A comparison of PCR-based markers for the molecular identification of Sphagnum species of the section Acutifolia

    Directory of Open Access Journals (Sweden)

    Jakub Sawicki

    2011-07-01

    Full Text Available RAPDs, ISJs, ISSRs, ITS and katGs were applied to determine genetic relationships between common Sphagnum species of the section Acutifolia. Twenty populations were genotyped using ten ISJ primers, 12 pairs of katG primers, 10 ISSR and 10 RAPD primers, and a restriction analysis of ITS1 and ITS2. ISSR and katG markers revealed the greatest number of species-specific bands. An analysis of ITS1 and ITS2 regions with restriction enzymes also proved to be a highly effective tool for species identification.

  4. A new Cernosvitoviella species (Clitellata: Enchytraeidae) and its comparison with other Cernosvitoviella species from Sphagnum mires in Hungary.

    Science.gov (United States)

    Dózsa-Farkas, Klára; Csitári, Bianka; Felföldi, Tamás

    2017-04-18

    Results of a comparative investigation on five Cernosvitoviella species from Hungarian Sphagnum mires including their distribution and the description of a new species, Cernosvitoviella farkasi sp. n., are presented in this paper. Cernosvitoviella atrata, C. aggtelekiensis, C. crassoductus and C. farkasi sp. n. could be easily distinguished from each other based on both morphological and molecular taxonomic analyses. However, C. minor seems to be a species complex on the basis of these investigations, so it was referred as C. minor sensu lato. The status of the C. minor variants requires further studies.

  5. Net photosynthesis in Sphagnum mosses has increased in response to the last century's 100 ppm increase in atmospheric CO2

    Science.gov (United States)

    Serk, Henrik; Nilsson, Mats; Schleucher, Jurgen

    2017-04-01

    Peatlands store >25% of the global soil C pool, corresponding to 1/3 of the contemporary CO2-C in the atmosphere. The majority of the accumulated peat is made up by remains of Sphagnum peat mosses. Thus, understanding how various Sphagnum functional groups respond, and have responded, to increasing atmospheric CO2 and temperature constitutes a major challenge for our understanding of the role of peatlands under a changing climate. We have recently demonstrated (Ehlers et al., 2015, PNAS) that the abundance ratio of two deuterium isotopomers (molecules carrying D at specific intramolecular positions, here D6R/S) of photosynthetic glucose reflects the ratio of oxygenation to carboxylation metabolic fluxes at Rubisco. The photosynthetic glucose is prepared from various plant carbohydrates including cellulose. This finding has been established in CO2 manipulation experiments and observed in carbohydrate derived glucose isolated from herbarium samples of all investigated C-3 species. The isotopomer ratio is connected to specific enzymatic processes thus allowing for mechanistic implicit interpretations. Here we demonstrate a clear increase in net photosynthesis of Sphagnum fuscum in response to the increase of 100 ppm CO2 during the last century as deduced from analysis on S. fuscum remains from peat cores. The D6R/S ratio declines from bottom to top in peat cores, indicating CO2-driven reduction of photorespiration in contemporary moss biomass. In contrast to the hummock-forming S. fuscum, hollow-growing species, e.g. S. majus did not show this response or gave significantly weaker response, suggesting important ecological consequences of rising CO2 on peatland ecosystem services. We hypothesize that photosynthesis in hollow-growing species under water saturation is fully or partly disconnected from the atmospheric CO2 partial pressure and thus showing weaker or no response to increased atmospheric CO2. To further test the field observations we grow both hummock and

  6. Sphagnum-dominated bog systems are highly effective yet variable sources of bio-available iron to marine waters

    Energy Technology Data Exchange (ETDEWEB)

    Krachler, Regina, E-mail: regina.krachler@univie.ac.at [Institute of Inorganic Chemistry, University of Vienna, Währingerstraße 42, 1090 Vienna (Austria); Krachler, Rudolf F.; Wallner, Gabriele [Institute of Inorganic Chemistry, University of Vienna, Währingerstraße 42, 1090 Vienna (Austria); Steier, Peter [Isotope Research and Nuclear Physics, University of Vienna, Währingerstraße 17, 1090 Vienna (Austria); El Abiead, Yasin; Wiesinger, Hubert [Institute of Inorganic Chemistry, University of Vienna, Währingerstraße 42, 1090 Vienna (Austria); Jirsa, Franz [Institute of Inorganic Chemistry, University of Vienna, Währingerstraße 42, 1090 Vienna (Austria); University of Johannesburg, Department of Zoology, P. O. Box 524, Auckland Park 2006 (South Africa); Keppler, Bernhard K. [Institute of Inorganic Chemistry, University of Vienna, Währingerstraße 42, 1090 Vienna (Austria)

    2016-06-15

    Iron is a micronutrient of particular interest as low levels of iron limit primary production of phytoplankton and carbon fluxes in extended regions of the world's oceans. Sphagnum-peatland runoff is extraordinarily rich in dissolved humic-bound iron. Given that several of the world's largest wetlands are Sphagnum-dominated peatlands, this ecosystem type may serve as one of the major sources of iron to the ocean. Here, we studied five near-coastal creeks in North Scotland using freshwater/seawater mixing experiments of natural creek water and synthetic seawater based on a {sup 59}Fe radiotracer technique combined with isotopic characterization of dissolved organic carbon by Accelerator Mass Spectrometry. Three of the creeks meander through healthy Sphagnum-dominated peat bogs and the two others through modified peatlands which have been subject to artificial drainage for centuries. The results revealed that, at the time of sampling (August 16–24, 2014), the creeks that run through modified peatlands delivered 11–15 μg iron per liter creek water to seawater, whereas the creeks that run through intact peatlands delivered 350–470 μg iron per liter creek water to seawater. To find out whether this humic-bound iron is bio-available to marine algae, we performed algal growth tests using the unicellular flagellated marine prymnesiophyte Diacronema lutheri and the unicellular marine green alga Chlorella salina, respectively. In both cases, the riverine humic material provided a highly bio-available source of iron to the marine algae. These results add a new item to the list of ecosystem services of Sphagnum-peatlands. - Highlights: • We report that peat-bogs are sources of bio-available iron to marine algae. • This iron is effectively chelated with aquatic humic acids. • The radiocarbon age of the iron-carrying aquatic humic acids was up to 550 years. • Analysis was focused on mixing experiments of iron-rich creek water with seawater. • Drained

  7. Resiliencia, Personalidad Resistente y Crecimiento en Cuidadores de Personas con Demencia en el Entorno Familiar: Una Revisión

    Directory of Open Access Journals (Sweden)

    Violeta Fernández-Lansac

    2011-01-01

    Full Text Available La investigación en torno al cuidado no profesional de mayores con demencia ha proliferado a lo largo de los últimos años, constatando muchos autores que, del mismo modo en que el cuidado se asocia a un buen número de consecuencias negativas, diversos efectos positivos pueden derivarse de esta experiencia. Sin embargo, y a pesar del impacto de la corriente positiva en la actualidad, son muy escasos los estudios que valoran la personalidad resistente (hardiness, la resiliencia y el crecimiento personal en cuidadores. El presente artículo hace una revisión sistemática de las contribuciones más relevantes a este campo, a partir del análisis de nueve publicaciones. Todos estos trabajos evalúan, de un modo cuantitativo, la resiliencia, el hardiness o el crecimiento en familiares de personas con demencia. Las características y resultados de dichos trabajos serán valoradas, teniendo en consideración sus implicaciones para el estudio y la atención a los cuidadores

  8. Soil temperature synchronisation improves estimation of daily variation of ecosystem respiration in Sphagnum peatlands

    Science.gov (United States)

    D'Angelo, Benoît; Gogo, Sébastien; Le Moing, Franck; Jégou, Fabrice; Guimbaud, Christophe; Laggoun, Fatima

    2015-04-01

    Ecosystem respiration (ER) is a key process in the global C cycle and thus, plays an important role in the climate regulation. Peatlands contain a third of the world soil C in spite of their relatively low global area (3% of land area). Although these ecosystems represent potentially a significant source of C under global change, they are still not taken into account accordingly in global climatic models. Therefore, ER variations have to be accounted for, especially by estimating its dependence to temperature.s The relationship between ER and temperature often relies only on one soil temperature depth and the latter is generally taken in the first 10 centimetres. Previous studies showed that the temperature dependence of ER depends on the depth at which the temperature is recorded. The depth selection for temperature measurement is thus a predominant issue. A way to deal with this is to analyse the time-delay between ER and temperature. The aim of this work is to assess whether using synchronised data in models leads to a better ER daily variation estimation than using non-synchronised data. ER measurements were undertaken in 2013 in 4 Sphagnum peatlands across France: La Guette (N 47°19'44', E 2°17'04', 154m) in July, Landemarais (N 48°26'30', E -1°10'54', 145m) in August, Frasne (N 46°49'35', E 6°10'20', 836m) in September, and Bernadouze (N 42°48'09', E 1°25'24', 1500m) in October. A closed method chamber was used to measure ER hourly during 72 hours in each of the 4 replicates installed in each site. Average ER ranged from 1.75 μmol m-2 s-1 to 6.13 μmol m-2 s-1. A weather station was used to record meteorological data and soil temperature profiles (5, 10, 20 and 30 cm). Synchronised data were determined for each depth by selecting the time-delay leading to the best correlation between ER and soil temperature. The data were used to simulate ER according to commonly used equations: linear, exponential with Q10, Arrhenius, Lloyd and Taylor. Models

  9. Investigating the internal structure of four Azorean Sphagnum bogs using ground-penetrating radar

    Directory of Open Access Journals (Sweden)

    D. Pereira

    2017-08-01

    Full Text Available This study evaluates the applicability of ground penetrating radar (GPR as a technique for determining the thickness and internal structure of four peat deposits on Terceira Island (Azores archipelago, mid-Atlantic region. The peatlands studied are all Sphagnum mires located above 500 m a.s.l., but they differ hydrogenetically and in their degree of naturalness. Radargrams for all four bogs, obtained using both 100 MHz and 500 MHz GPR antennae, are presented and compared. The radargram data were validated against peat characteristics (bulk density, von Post H, US method obtained by direct sampling (‘open cores’ across the whole peat profile at each site. A scheme of ‘soft scoring’ for degree of naturalness (DN of the peatland was developed and used as an additional validation factor. The GPR data were positively correlated with DN, and relationships between GPR data, peat bulk density and degree of humification (H were also found. From the radargrams it was possible to distinguish the interface between the peat and the mineral substratum as well as some of the internal structure of the peat deposit, and thus to derive the total thickness of the peat deposit and (in some cases the thicknesses of its constituent layers. The first evaluation of the propagation velocity of electromagnetic waves in Azorean peat yielded a value of 0.04 m ns-1 for 100 MHz and 500 MHz radar antennae. For one of the study sites, the GPR data were analysed using GIS software to produce tridimensional models and thus to estimate the volumes of peat layers. This type of analysis has potential utility for quantifying some of the ecosystem services provided by peatlands.

  10. Inoculation of sphagnum-based soil substrate with entomopathogenic fungus Isaria fumosorosea (Hypocreales: Cordycipitaceae)

    Science.gov (United States)

    Zemek, Rostislav; Konopická, Jana; Bohatá, Andrea

    2018-04-01

    Convenient ecological alternative to broad-spectrum chemical pesticides is the utilization of natural enemies, like predators, parasitoids and microorganisms. A substantial number of microbial biopesticides based on entomopathogenic fungi have been developed worldwide since 1960s. Beauveria bassiana (Balsamo-Crivelli) Vuillemin, Metarhizium anisopliae (Metchnikoff) Sorokin, Isaria fumosorosea (Wize), and B. brongniartii (Saccardo) Petch are the most common species used in commercially produced mycopesticides. Besides direct biological pest control, these fungi could be also used in preventive application programs, particularly in ornamental or nursery plants to provide better control against pests. The aim of the present study was to investigate potential of pre-colonization of sphagnum-based soil substrate with I. fumosorosea strain CCM 8367 which was found earlier to be highly virulent against several pest species. We developed simple laboratory apparatus for application of fungal spore suspension into the substrate. Suspension was prepared from blastospores obtained by submerged cultivation on potato dextrose broth (PDB) medium using an orbital shaker. Inoculated substrate was placed into plastic bags and stored at constant temperature for six months. Every month, samples were analyzed for concentration of colony forming units (CFU) by elution and selective medium technique. The results showed that at 20°C the fungus successfully colonized the soil substrate and persisted there although the mean concentration slightly decreased from 5.89×104 to 2.76×104 CFU per milliliter of substrate during the experiment. Temperature 30°C had negative effect on survival of the fungus and is not recommended for long-term storage of pre-inoculated substrate. We can conclude that I. fumosorosea-colonized substrate can be convenient for preventive and permanent protection of various plants against soil-dwelling pests.

  11. Manejo da Planta Daninha Brachiaria plantaginea Resistente aos herbicidas Inibidores da ACCase Management of the Weed Brachiaria plantaginea Resistant to ACCase Inhibitor Herbicides

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    P.J. Christoffoleti

    2001-04-01

    Full Text Available O objetivo deste trabalho foi estudar o manejo de uma população da planta daninha capim-marmelada (Brachiaria plantaginea resistente aos herbicidas inibidores da ACCase (ariloxifenoxipropionatos e ciclohexanodionas, utilizados na cultura da soja no sistema de plantio direto. Para isso, foram realizados dois experimentos: um utilizando herbicidas de manejo, com mecanismos de ação alternativos, comparando a eficácia destes com os inibidores da ACCase; e outro apenas com herbicidas inibidores da ACCase e aditivos misturados à calda. As sementes resistentes foram produzidas a partir de plantas comprovadamente resistentes; para comparação de resultados, foi utilizada uma população de capim-marmelada que nunca tinha sido pulverizada com inibidores da ACCase, portanto uma população suscetível. O experimento com os herbicidas de manejo foi realizado em condições de campo, porém as plantas ficaram em caixas com capacidade de 50 L, evitando-se a disseminação destas para áreas adjacentes. Concluiu-se que as plantas resistentes não apresentam resistência múltipla com herbicidas de manejo com mecanismos de ação alternativos, podendo os herbicidas glyphosate, paraquat, sulfosate, paraquat + diuron, MSMA e glufosinate ser utilizados no período entressafra das áreas com sistema de plantio direto, para manejo de populações resistentes de capim-marmelada aos herbicidas inibidores da ACCase. O experimento com aditivos foi realizado em casa de vegetação, com plantas em vasos individuais, utilizando sementes das populações suscetíveis e resistentes. Os herbicidas utilizados foram inibidores da ACCase, em cuja calda foram adicionados aditivos nitrogenados, do tipo uréia e sulfato de amônio, além de um tratamento sem aditivos. Concluiu-se que os aditivos não alteraram a eficácia dos herbicidas inibidores da ACCase nas plantas provenientes tanto da população suscetível quanto da resistente.The objective of this research was to

  12. Dynamics of Viral Abundance and Diversity in a Sphagnum-Dominated Peatland: Temporal Fluctuations Prevail Over Habitat.

    Science.gov (United States)

    Ballaud, Flore; Dufresne, Alexis; Francez, André-Jean; Colombet, Jonathan; Sime-Ngando, Télesphore; Quaiser, Achim

    2015-01-01

    Viruses impact microbial activity and carbon cycling in various environments, but their diversity and ecological importance in Sphagnum-peatlands are unknown. Abundances of viral particles and prokaryotes were monitored bi-monthly at a fen and a bog at two different layers of the peat surface. Viral particle abundance ranged from 1.7 x 10(6) to 5.6 x 10(8) particles mL(-1), and did not differ between fen and bog but showed seasonal fluctuations. These fluctuations were positively correlated with prokaryote abundance and dissolved organic carbon, and negatively correlated with water-table height and dissolved oxygen. Using shotgun metagenomics we observed a shift in viral diversity between winter/spring and summer/autumn, indicating a seasonal succession of viral communities, mainly driven by weather-related environmental changes. Based on the seasonal asynchrony between viral and microbial diversity, we hypothesize a seasonal shift in the active microbial communities associated with a shift from lysogenic to lytic lifestyles. Our results suggest that temporal variations of environmental conditions rather than current habitat differences control the dynamics of virus-host interactions in Sphagnum-dominated peatlands.

  13. Sulphur, nitrogen and carbon content of Sphagnum capillifolium and Pseudevernia furfuracea exposed in bags in the Naples urban area

    International Nuclear Information System (INIS)

    Vingiani, S.; Adamo, P.; Giordano, S.

    2004-01-01

    The accumulation ability of the major elements sulphur, nitrogen and carbon by the moss Sphagnum capillifolium (Ehrh.) Hedw. and the lichen Pseudevernia furfuracea (L.) Zopf exposed in bags in Naples urban area,was investigated. Bags were exposed at the beginning of July 1999 and gathered in two subsequent moments: at the end of the dry season (after 10 weeks of exposure) and during the wet season (after 17 weeks of exposure), to include the effects of rainy conditions. Sulphur and N content of the lichen increased all over the exposure period, while the level of C did not change significantly either after 10 or 17 weeks of exposition. For the moss the S accumulation was limited to the dry period of exposure, whereas N and C content decreased with exposure. Results, in contrast with those obtained in a previous study on trace elements bioaccumulation [Adamo et al., Environmental Pollution, (2003) 122, 91-103], suggest that accumulation of gaseous pollutants is strongly influenced by biomonitor vitality and that lichen bags are a more reliable and effective tool for monitoring S, N and C atmospheric depositions in urban areas compared to moss bags, because of greater lichen resistance to dry and stressing conditions of urban environment. - The lichen Pseudevernia furfuracea is more effective than the moss Sphagnum capillifolium as S and N pollutants biomonitor

  14. Sphagnum mosses from 21 ombrotrophic bogs in the athabasca bituminous sands region show no significant atmospheric contamination of "heavy metals".

    Science.gov (United States)

    Shotyk, William; Belland, Rene; Duke, John; Kempter, Heike; Krachler, Michael; Noernberg, Tommy; Pelletier, Rick; Vile, Melanie A; Wieder, Kelman; Zaccone, Claudio; Zhang, Shuangquan

    2014-11-04

    Sphagnum moss was collected from 21 ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca bituminous sands in Alberta (AB). In comparison to contemporary Sphagnum moss from four bogs in rural locations of southern Germany (DE), the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb, and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th, and V. Except for V, in comparison to the "cleanest", ancient peat samples ever tested from the northern hemisphere (ca. 6000-9000 years old), the concentrations of each of these metals in the AB mosses are within a factor of 3 of "natural, background" values. The concentrations of "heavy metals" in the mosses, however, are proportional to the concentration of Th (a conservative, lithophile element) and, therefore, contributed to the plants primarily in the form of mineral dust particles. Vanadium, the single most abundant trace metal in bitumen, is the only anomaly: in the AB mosses, V exceeds that of ancient peat by a factor of 6; it is therefore enriched in the mosses, relative to Th, by a factor of 2. In comparison to the surface layer of peat cores collected in recent years from across Canada, from British Columbia to New Brunswick, the Pb concentrations in the mosses from AB are far lower.

  15. Contrasting diversity of testate amoebae communities in Sphagnum and brown-moss dominated patches in relation to shell counts.

    Science.gov (United States)

    Lizoňová, Zuzana; Horsák, Michal

    2017-04-01

    Ecological studies of peatland testate amoebae are generally based on totals of 150 individuals per sample. However, the suitability of this standard has never been assessed for alkaline habitats such as spring fens. We explored the differences in testate amoeba diversity between Sphagnum and brown-moss microhabitats at a mire site with a highly diversified moss layer which reflects the small-scale heterogeneity in groundwater chemistry. Relationships between sampling efficiency and sample completeness were explored using individual-based species accumulation curves and the effort required to gain an extra species was assessed. Testate amoeba diversity differed substantially between microhabitats, with brown mosses hosting on average twice as many species and requiring greater shell totals to reach comparable sample analysis efficiency as for Sphagnum. Thus, for samples from alkaline conditions an increase in shell totals would be required and even an overall doubling up to 300 individuals might be considered for reliable community description. Our small-scale data are likely not robust enough to provide an ultimate solution for the optimization of shell totals. However, the results proved that testate amoebae communities from acidic and alkaline environments differ sharply in both species richness and composition and they might call for different methodological approaches. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. To what extent do food preferences explain the trophic position of heterotrophic and mixotrophic microbial consumers in a Sphagnum peatland?

    Science.gov (United States)

    Jassey, Vincent E J; Meyer, Caroline; Dupuy, Christine; Bernard, Nadine; Mitchell, Edward A D; Toussaint, Marie-Laure; Metian, Marc; Chatelain, Auriel P; Gilbert, Daniel

    2013-10-01

    Although microorganisms are the primary drivers of biogeochemical cycles, the structure and functioning of microbial food webs are poorly studied. This is the case in Sphagnum peatlands, where microbial communities play a key role in the global carbon cycle. Here, we explored the structure of the microbial food web from a Sphagnum peatland by analyzing (1) the density and biomass of different microbial functional groups, (2) the natural stable isotope (δ(13)C and δ(15)N) signatures of key microbial consumers (testate amoebae), and (3) the digestive vacuole contents of Hyalosphenia papilio, the dominant testate amoeba species in our system. Our results showed that the feeding type of testate amoeba species (bacterivory, algivory, or both) translates into their trophic position as assessed by isotopic signatures. Our study further demonstrates, for H. papilio, the energetic benefits of mixotrophy when the density of its preferential prey is low. Overall, our results show that testate amoebae occupy different trophic levels within the microbial food web, depending on their feeding behavior, the density of their food resources, and their metabolism (i.e., mixotrophy vs. heterotrophy). Combined analyses of predation, community structure, and stable isotopes now allow the structure of microbial food webs to be more completely described, which should lead to improved models of microbial community function.

  17. Origins, genetic structure, and systematics of the narrow endemic peatmosses (Sphagnum): S. guwassanense and S. triseriporum (Sphagnaceae).

    Science.gov (United States)

    Shaw, A Jonathan; Shaw, Blanka; Johnson, Matthew G; Higuchi, Masanobu; Arikawa, Tomotsugu; Ueno, Takeshi; Devos, Nicolas

    2013-06-01

    Sphagnum dominates vast expanses of wetland habitats throughout the northern hemisphere and species delimitation within the genus is important because floristic changes associated with a warming global climate may have measureable impacts on large-scale ecological processes. Most northern hemisphere peatmoss species (Sphagnum) have circumboreal ranges, but the Japanese species generally known as S. calymmatophyllum is endemic to Honshu Island. This prompted a population genetic and phylogenetic analysis to resolve the origin(s), population structure, and phylogenetic relationships of this morphologically variable species. • Sixty plants collected from Mt. Gassan and Mt. Hakkoda were genotyped for 12 microsatellite loci. Two plastid loci and three anonymous nuclear loci were sequenced in a subset of the plants, plus representatives from 10 closely related species. • Gametophytes exhibited fixed or nearly fixed heterozygosity at 9-10 of the 12 microsatellite loci. Two genetic groups were resolved by the microsatellite data, individuals showed no evidence of admixture, and the two groups of plants differ in morphology. They are heterozygous for different sets of alleles. The two taxa share plastid DNA sequences with two species that are common in Alaska. • Two taxa were distinguished: S. guwassanense and S. triseriporum. Both are allopolyploids; they originated independently from different but closely related progenitors. The maternal progenitor was likely either S. orientale or S. inexspectatum. The two allopolyploid taxa are heterozygous for (different) private microsatellite alleles, and one progenitor could be extinct.

  18. Nitrous oxide emission potentials of Burkholderia species isolated from the leaves of a boreal peat moss Sphagnum fuscum.

    Science.gov (United States)

    Nie, Yanxia; Li, Li; Wang, Mengcen; Tahvanainen, Teemu; Hashidoko, Yasuyuki

    2015-01-01

    Using a culture-based nitrous oxide (N2O) emission assay, three active N2O emitters were isolated from Sphagnum fuscum leaves and all identified as members of Burkholderia. These isolates showed N2O emission in the medium supplemented with [Formula: see text] but not with [Formula: see text], and Burkholderia sp. SF-E2 showed the most efficient N2O emission (0.20 μg·vial(-1)·day(-1)) at 1.0 mM KNO3. In Burkholderia sp. SF-E2, the optimum pH for N2O production was 5.0, close to that of the phyllosphere of Sphagnum mosses, while the optimum temperature was uniquely over 30 °C. The stimulating effect of additional 1.5 mM sucrose on N2O emission was ignorable, but Burkholderia sp. SF-E2 upon exposure to 100 mg·L(-1) E-caffeic acid showed uniquely 67-fold higher N2O emission. All of the three N2O emitters were negative in both acetylene inhibition assay and PCR assay for nosZ-detection, suggesting that N2O reductase or the gene itself is missing in the N2O-emitting Burkholderia.

  19. Mercury methylation in Sphagnum moss mats and its association with sulfate-reducing bacteria in an acidic Adirondack forest lake wetland.

    Science.gov (United States)

    Yu, Ri-Qing; Adatto, Isaac; Montesdeoca, Mario R; Driscoll, Charles T; Hines, Mark E; Barkay, Tamar

    2010-12-01

    Processes leading to the bioaccumulation of methylmercury (MeHg) in northern wetlands are largely unknown. We have studied various ecological niches within a remote, acidic forested lake ecosystem in the southwestern Adirondacks, NY, to discover that mats comprised of Sphagnum moss were a hot spot for mercury (Hg) and MeHg accumulation (190.5 and 18.6 ng g⁻¹ dw, respectively). Furthermore, significantly higher potential methylation rates were measured in Sphagnum mats as compared with other sites within Sunday Lake's ecosystem. Although MPN estimates showed a low biomass of sulfate-reducing bacteria (SRB), 2.8 × 10⁴ cells mL⁻¹ in mat samples, evidence consisting of (1) a twofold stimulation of potential methylation by the addition of sulfate, (2) a significant decrease in Hg methylation in the presence of the sulfate reduction inhibitor molybdate, and (3) presence of dsrAB-like genes in mat DNA extracts, suggested that SRB were involved in Hg methylation. Sequencing of dsrB genes indicated that novel SRB, incomplete oxidizers including Desulfobulbus spp. and Desulfovibrio spp., and syntrophs dominated the sulfate-reducing guild in the Sphagnum moss mat. Sphagnum, a bryophyte dominating boreal peatlands, and its associated microbial communities appear to play an important role in the production and accumulation of MeHg in high-latitude ecosystems. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  20. High specificity but contrasting biodiversity of Sphagnum-associated bacterial and plant communities in bog ecosystems independent of the geographical region.

    Science.gov (United States)

    Opelt, Katja; Berg, Christian; Schönmann, Susan; Eberl, Leo; Berg, Gabriele

    2007-10-01

    Mosses represent ecological niches that harbor a hitherto largely uncharacterized microbial diversity. To investigate which factors affect the biodiversity of bryophyte-associated bacteria, we analyzed the bacterial communities associated with two moss species, which exhibit different ecological behaviors and importance in bog ecosystems, Sphagnum magellanicum and Sphagnum fallax, from six temperate and boreal bogs in Germany and Norway. Furthermore, their surrounding plant communities were studied. Molecular analysis of bacterial communities was determined by single-strand conformation polymorphism (SSCP) analysis using eubacterial and genus-specific primers for the dominant genera Burkholderia and Serratia as well as by sequence analysis of a Burkholderia 16S rRNA gene clone library. Plant communities were analyzed by monitoring the abundance and composition of bryophyte and vascular plant species, and by determining ecological indicator values. Interestingly, we found a high degree of host specificity for associated bacterial and plant communities of both Sphagnum species independent of the geographical region. Calculation of diversity indices on the basis of SSCP gels showed that the S. fallax-associated communities displayed a statistically significant higher degree of diversity than those associated with S. magellanicum. In contrast, analyses of plant communities of Sphagnum-specific habitats resulted in a higher diversity of S. magellanicum-specific habitats for all six sites. The higher content of nutrients in the S. fallax-associated ecosystems can explain higher diversity of microorganisms.

  1. The Roles of Sphagnum and Cyperaceae in the Methane Cycle of an Ombrotrophic Bog Revealed by the Carbon Isotope Ratios of Leaf Waxes

    Science.gov (United States)

    Isles, P. D.; Nichols, J. E.; Peteet, D. M.; Kenna, T. C.

    2011-12-01

    Methane is a strong greenhouse gas, and the role of the terrestrial carbon cycle in the concentrations of atmospheric methane is poorly understood. What is clear, is that northern peatlands are a significant source of methane to the atmosphere. A recent discovery, and a topic of much scrutiny, has been the relationship between Sphagnum in peatlands and symbiotic methanotrophic bacteria. These bacteria oxidize methane produced at depth in peatlands before it is released to the atmosphere, contributing 13C-depleted CO2 to Sphagnum photosynthate. We seek to better understand the fate of methane produced in peatlands at depth, and the relationship between methane release from peatland surfaces and parameters such as temperature, moisture, and vegetation type. We compare carbon isotope ratios of leaf wax n-alkanes from sphagnum and vascular plants and major element chemistry at three different microhabitats, hummock, hollow, and sedge tussock, in Mer Bleue an ombrotrophic peatland near Ottowa, Ontario, Canada. We use these compound-specific carbon isotope measurements to constrain the amount of methane-derived CO2 incorporated by Sphagnum. We also compare our multiannually resolved down-core measurements to data from long-term monitoring of climate parameters and methane flux from the same microhabitats to ground-truth our sedimentary signature of methane with instrumental measurements.

  2. Herbicidas alternativos para o controle de Conyza sumatrensis (Retz. E. H. Walker resistentes aos inibidores da ALS e EPSPs

    Directory of Open Access Journals (Sweden)

    Fernando Machado dos Santos

    2015-12-01

    Full Text Available RESUMO A buva (Conyza sumatrensis, uma das principais plantas daninhas já identificadas no sul do Brasil, vem apresentando controle insatisfatório, em resposta à aplicação dos herbicidas chlorimuron-ethyl e glyphosate. Por esta razão, o objetivo deste estudo foi avaliar herbicidas alternativos, visando ao controle de biótipos de C. sumatrensis, com resistência de nível baixo ao herbicida chlorimuron-ethyl e resistentes ao herbicida glyphosate. O experimento foi realizado em casa de vegetação, entre abril e agosto de 2012, no município de Passo Fundo, RS. O delineamento experimental foi o inteiramente casualizado, com quatro repetições, sendo avaliados 15 tratamentos com herbicidas, além de uma testemunha sem aplicação. As variáveis consideradas foram controle percentual, aos 14, 21 e 28 dias após a aplicação dos tratamentos (DAT e a matéria seca da parte aérea, aos 28 DAT. Como resultados, observou-se que os biótipos foram 100% controlados, aos 28 DAT, pelos tratamentos alternativos de paraquat + diuron; ammonium glufosinate; glyphosate + 2,4-D; glyphosate + ammonium glufosinate; 2,4-D; tembotrione e tembotrione + atrazine. O biótipo 17 evidenciou menor sensibilidade aos herbicidas inibidores da ALS e os biótipos 05, 17 e 20 não foram controlados pelo herbicida glyphosate.

  3. Eficácia do sulfato de aminosidine na leishmaniose visceral grave, resistente ao tratamento com antimonial pentavalente

    Directory of Open Access Journals (Sweden)

    Cleudson Castro

    1995-09-01

    Full Text Available Descreve-se um caso de calazar grave resistente a dez cursos de antimonial petitavalente (glucantime à base de 20mg de Sb5/kg/dia, que respondeu favoravelmente ao sulfato de aminosidine intramuscular na dose de 20mg/kg/dia por 20 dias, repetido após 20 dias. O parasitismo esplénico passou de 50 parasitos por campo a 3 parasitos em 10 campos logo após a primeira série de sulfato de aminosidine, tornando-se negativo depois de sete meses. A melhora clínica foi imediata, com redução gradual da hepatoesplenomegalia, e desaparecimento 26 meses após. Neste período aumentou 13 kg. Após o uso de aminosidine a reação de Monténégro tornou-se positiva e as células mononucleares responderam quando estimuladas com antígenos de leishmânia.A grave kala-azar infection in a 14 years old boy is described. The leishmanial infection failed to respond to ten interrupted courses of glucantime of variable duration (14-56 days at a dose of 20mg Sb5/kg/day. However a favorable response ocurred to intramuscular aminosidine sulphate (20mg/kg/day for 20 days. This same regimen was repeated 20 days later. After the first treatment splenic puncture parasite density fell from 50 amastigotes per oil immersion field to 3 amastigotes in 10 fields. A further splenic puncture 7 months after treatment was negative. The marked hepatoesplenomegaly gradually resolved over 26 months follow up and he gained 13 kilogramas in weight. After aminosidine sulphate therapy his Montenegro reaction become positive and his lymphocytes responded to leishmania antigens.

  4. Incremento de las infecciones por Staphylococcus aureus resistente a meticilina en un hospital pediátrico de Cuba.

    Directory of Open Access Journals (Sweden)

    Alexis Monzote López

    2016-01-01

    Full Text Available Objetivo: Definir la tasa de resistencia a la meticilina entre los aislamientos de Staphylococcus aureus investigados y describir la susceptibilidad a los antimicrobianos no betalactámicos. Método: Se realizó un estudio observacional prospectivo durante el período 2010-2012 en el Hospital Pediátrico “Juan Manuel Márquez” de La Habana, que incluyó 333 aislamientos de Staphylococcus aureus resistente a la meticilina (SARM, recuperados a partir de diferentes muestras clínicas de pacientes hospitalizados. Para la confirmación de SARM se emplearon los métodos de difusión con discos de cefoxitina y el de microdilución en caldo para la oxacilina. La susceptibilidad a 14 antimicrobianos no betalactámicos se realizó por el método de microdilución en caldo y el de difusión en disco (Bauer-Kirby. Resultados: Se demostró una alta tasa de resistencia a la meticilina (52,4% - 59,3%. Se puso de manifiesto la emergencia de infecciones de la piel y tejidos blandos (62,5% por SARM. Se corroboró una alta resistencia a la eritromicina (82% y la ciprofloxacina (73,5%. La sensibilidad frente al cotrimoxazol, la clindamicina y la vancomicina los ratificaron como antimicrobianos de primera línea para el tratamiento. Conclusiones: Se evidencia una tendencia al incremento de las infecciones por SARM y se señala como un problema clínico epidemiológico emergente para los diferentes servicios del hospital, que demanda la implementación de un sistema para su activa vigilancia y control.

  5. POTENCIAL DEL ALMIDÓN RESISTENTE RETROGRADADO DE PAPA FRENTE A OTROS ADITIVOS FUNCIONALES USADOS EN POLLOS DE ENGORDE

    Directory of Open Access Journals (Sweden)

    D. Rodríguez-Aguilar

    2014-01-01

    Full Text Available El almidón resistente retrogradado (AR3 de las variedades de papa Pastusa (Solanum tuberosum grupo tuberosum y Guaneña (Solanum tuberosum grupo phureja fue evaluado como aditivo funcional con características similares a la fibra dietaria y por su potencial prebiótico en pollos de engorde. Se asignaron aleatoriamente 792 pollos machos Ross de un día de edad a uno de cinco tratamientos experimentales bajo un diseño completamente al azar. Se evaluaron niveles de suplementación de 1,0% de AR3 –Pastusa (AR3P y Guaneña (AR3G–, frente a manano-oligosacáridos (MOS, 0,5%, carboximetilcelulosa (CMC, 1%, levadura comercial (LEV, 0,5% y un control sin suplementar. Los datos se analizaron mediante el procedimiento GLM del programa SAS®. MOS y AR3P mostraron el mayor peso y ganancia de peso corporal al día 42 de edad (P<0,05, MOS presentó el menor consumo de alimento frente al tratamiento CMC (P<0,05, con una mejor conversión alimenticia comparado con CMC y el control sin suplementar (P<0,05. Los grupos AR3P y AR3G tuvieron un comportamiento intermedio para la conversión de alimento. El mayor porcentaje de eficiencia americana e índice de productividad fue para MOS, seguido de AR3P frente al control sin suplementar (P<0,05. Con referencia al ingreso neto parcial por pollo fraccionado, MOS mostró el mayor ingreso comparado con AR3G, observando para los demás tratamientos un comportamiento intermedio (P<0,05. Los resultados sugieren que el AR3P tiene potencial para ser usado como un aditivo funcional en dietas para pollos de engorde durante un ciclo comercial de producción.

  6. Freezing cytorrhysis and critical temperature thresholds for photosystem II in the peat moss Sphagnum capillifolium.

    Science.gov (United States)

    Buchner, Othmar; Neuner, Gilbert

    2010-07-01

    Leaflets of Sphagnum capillifolium were exposed to temperatures from -5 degrees C to +60 degrees C under controlled conditions while mounted on a microscope stage. The resultant cytological response to these temperature treatments was successfully monitored using a light and fluorescence microscope. In addition to the observable cytological changes during freezing cytorrhysis and heat exposure on the leaflets, the concomitant critical temperature thresholds for inactivation of photosystem II (PS II) were studied using a micro fibre optic and a chlorophyll fluorometer mounted to the microscope stage. Chlorophyllous cells of S. capillifolium showed extended freezing cytorrhysis immediately after ice nucleation at -1.1 degrees C in the water in which the leaflets were submersed during the measurement. The occurrence of freezing cytorrhysis, which was visually manifested by cell shrinkage, was highly dynamic and was completed within 2 s. A total reduction of the mean projected diameter of the chloroplast containing area during freezing cytorrhysis from 8.9 to 3.8 microm indicates a cell volume reduction of approximately -82%. Simultaneous measurement of chlorophyll fluorescence of PS II was possible even through the frozen water in which the leaf samples were submersed. Freezing cytorrhysis was accompanied by a sudden rise of basic chlorophyll fluorescence. The critical freezing temperature threshold of PS II was identical to the ice nucleation temperature (-1.1 degrees C). This is significantly above the temperature threshold at which frost damage to S. capillifolium leaflets occurs (-16.1 degrees C; LT(50)) which is higher than observed in most higher plants from the European Alps during summer. High temperature thresholds of PS II were 44.5 degrees C which is significantly below the heat tolerance of chlorophyllous cells (49.9 degrees C; LT(50)). It is demonstrated that light and fluorescence microscopic techniques combined with simultaneous chlorophyll fluorescence

  7. Personalidad resistente en maratonianos: un estudio sobre el control, compromiso y desafío de corredoras y corredores de maratón

    Directory of Open Access Journals (Sweden)

    Jos\\u00E9 Carlos Jaenes S\\u00E1nchez

    2009-01-01

    Full Text Available La Personalidad Resistente se refiere a una constelación de características de personalidad relacionadas con las percepciones personales de control, compromiso y desafío, que ha sido ampliamente estudiada en relación con el estrés y su impacto en contextos de salud y laborales, entre otros, pero prácticamente ignorada en el ámbito deportivo. Sin embargo, las características que incluye este constructo son muy interesantes para la práctica y el rendimiento deportivos. El objetivo de este estudio ha sido conocer las características de Personalidad Resistente de maratonianos adultos españoles. Los resultados, pioneros hasta la fecha, nos han permitido establecer que los niveles de compromiso, control y desafío de estos deportistas son moderadamente altos y que ejercen un impacto fundamental tanto a nivel motivacional (metas propuestas y resultados esperados como de rendimiento (marcas obtenidas. Se puede diferenciar entre maratonianos con mejores y peores marcas en relación con el nivel de PR, lo cual nos permite predecir el éxito de los maratonianos en función de sus características de PR. Como consecuencia, un entrenamiento adecuado en estas aracterísticas podría resultar en mejores cotas de rendimiento. Además, estos deportistas muestran mayores niveles de Personalidad Resistente que jóvenes y adultos de la población general, lo que podría ser un beneficio derivado de la práctica deportiva muy relevante en la vida cotidiana.

  8. Terapias somáticas para transtornos psiquiátricos resistentes ao tratamento Somatic therapies for treatment-resistant psychiatric disorders

    OpenAIRE

    Raphael J Braga; Georgios Petrides

    2007-01-01

    OBJETIVO: O presente artigo é uma revisão do conhecimento atual relativo às terapias somáticas em psiquiatria, com foco em transtornos psiquiátricos resistentes ao tratamento usual. MÉTODO: Foi realizada uma pesquisa computadorizada da literatura no Medline utilizando as palavras "eletroconvulsoterapia", "estimulação magnética transcraniana", "terapia magnética convulsiva", "estimulação do nervo vago" e "estimulação cerebral profunda", com todos os termos traduzidos para o idioma inglês. Refe...

  9. Estudo teórico-experimental da contribuição da armadura para a capacidade resistente de vigas parcialmente revestidas

    OpenAIRE

    Leandro de Amorim Cavalcanti

    2010-01-01

    Este trabalho tem por objetivo investigar a contribuição da armadura para a capacidade resistente de vigas mistas parcialmente revestidas, bem como sua eficiência para promover o comportamento conjunto aço-concreto, imprescindível para a obtenção de vigas mistas. O estudo engloba uma investigação experimental com ensaios de vigas sob flexão em quatro pontos e uma simulação numérica utilizando o pacote computacional DIANA®, visando obter dados do comportamento de vigas mistas parcialmente reve...

  10. Obtenção de plantas de feijão-caupi resistentes ao Cowpea severe mosaic virus e ao Cowpea aphid-borne mosaic virus

    Directory of Open Access Journals (Sweden)

    Gislanne Brito Barros

    2013-06-01

    Full Text Available Dentre os vírus que infectam o feijão-caupi (Vigna unguiculata L. Walp. destacam-se, respectivamente, pela severidade e ampla ocorrência o Cowpea severe mosaic virus (CPSMV e o Cowpea aphid-borne mosaic virus (CABMV. Portanto, objetivaram-se, no presente trabalho, obter e avaliar plantas de feijão-caupi com resistência ao CPSMV e ao CABMV, visando ao desenvolvimento de cultivares essencialmente derivadas e novas cultivares. Realizaram-se oito cruzamentos seguidos de retrocruzamentos, utilizando a linhagem TE 97-309G-9 e a cultivar Patativa como genitores resistentes, e as cultivares BR3-Tracuateua, BRS-Urubuquara, BRS-Novaera, BRS-Guariba e Pretinho como genitores suscetíveis. As gerações F2 e F2RC1 foram desafiadas quanto à resistência por meio de inoculação mecânica com isolados do CPSMV e do CABMV. Nas gerações F2RC1, além da resistência foram avaliados os caracteres: número de dias para o início da floração, comprimento das vagens, número de grãos. vagem-1, peso de cem grãos e produção de grãos.planta-1. Todos os indivíduos F2 e F2RC1 foram analisados pelo teste χ² e se ajustaram à frequência esperada de 15 plantas suscetíveis 1 planta resistente a ambos os vírus. As médias das plantas F2RC1 resistentes, de cada retrocruzamento, foram comparadas com a média do seu respectivo genitor recorrente pelo teste 't' e as médias dos retrocruzamentos foram comparadas pelo teste de Scott-Knott. Foi detectada variabilidade genética entre os retrocruzamentos para todos os caracteres. Todos os retrocruzamentos foram considerados promissores para produção de cultivares essencialmente derivadas resistentes ao CPSMV e ao CABMV e as plantas selecionadas possuem características que possibilitam a seleção de linhagens com grãos de bom padrão comercial e altamente produtivas.

  11. Factores psicológicos, demográficos y sociales asociados al estrés y a la Personalidad Resistente en adultos mayores

    OpenAIRE

    Zoila Edith Hernández Zamora; Yamilet Ehrenzeweig Sánchez; Axel Manuel Navarro Hernández

    2009-01-01

    Se muestran los resultados encontrados con relación al constructo Personalidad Resistente (PR) y los niveles de estrés en una muestra de 102 adultos mayores. La mayoría de los y las participantes tienen un nivel alto de PR y ninguno resultó con un nivel bajo en este constructo. Las variables asociadas significativamente con una PR alta son: sexo, independencia, escolaridad, autopercepción de salud y repercusión en el estado de ánimo de sus enfermedades. Las variables asociadas con un nivel de...

  12. Potencial de cruzamento natural entre o arroz transgênico resistente ao herbicida glufosinato de amônio e o arroz daninho

    OpenAIRE

    Noldin,J.A.; Yokoyama,S.; Antunes,P.; Luzzardi,R.

    2002-01-01

    A utilização de cultivares de arroz irrigado resistentes a herbicidas não-seletivos, como o glufosinato de amônio, pode se constituir numa alternativa de controle de arroz daninho em lavouras de arroz irrigado. O objetivo deste trabalho foi avaliar a taxa e o sentido do cruzamento natural entre plantas de uma linhagem modificada geneticamente para resistência ao herbicida glufosinato de amônio (arroz GM) e ao arroz daninho. A taxa de cruzamento natural entre o arroz GM como receptor feminino ...

  13. Avaliação da capacidade resistente última de estacas em compressão usando análises em tensão/deformação

    OpenAIRE

    Vieira, Ana Rita Ribeiro

    2013-01-01

    Dissertação para obtenção do Grau de Mestre em Engenharia Civil - Ramo de Estruturas e Geotecnia Nesta dissertação avalia-se a capacidade resistente última de estacas em compressão usando análises em tensão/deformação. A capacidade resistente última das estacas é avaliada através do programa computacional de elementos finitos Plaxis 2D v. 8 e é comparada com a capacidade resistente última prevista por métodos de extrapolação da curva carga vs. assetamento de ensaios de carga que não ...

  14. Plantas transgênicas resistentes a insetos e organismos não-alvo: predadores, parasitóides e polinizadores - doi: 10.5102/ucs.v4i1.23

    Directory of Open Access Journals (Sweden)

    Marina Regina Frizzas

    2008-04-01

    Full Text Available Plantas geneticamente modificadas resistentes aos insetos oferecem benefícios à agricultura moderna. No entanto, esta tecnologia pode afetar o controle biológico natural e a biodiversidade por meio de efeitos diretos e indiretos das plantas transgênicas sobre o valor adaptativo e comportamental de predadores, parasitóides, polinizadores e outros artrópodes não-alvo. Neste artigo, são discutidos os impactos ou os efeitos potenciais de plantas transgênicas resistentes a insetos sobre organismos não-alvo, com ênfase em artrópodes predadores, parasitóides e polinizadores, e os principais estudos com plantas transgênicas resistentes a insetos, publicados nos últimos dez anos.

  15. Active Sphagnum girgensohnii Russow Moss Biomonitoring of an Industrial Site in Romania: Temporal Variation in the Elemental Content.

    Science.gov (United States)

    Culicov, Otilia A; Zinicovscaia, Inga; Duliu, O G

    2016-05-01

    The moss-bag transplant technique was used to investigate the kinetics of the accumulation of 38 elements in Sphagnum girgensohni moss samples in the highly polluted municipality of Baia Mare, Romania. The moss samples collected from the unpolluted Vitosha Mountain Natural Reserve, Bulgaria, were analyzed after 1, 2, 3, and 4 months of exposure, respectively. The ANOVA method was used to assay the statistical significance of the observed changes in elemental content, as determined by neutron activation analysis. The content of Zn, Se, As, Ag, Cd, and Sb increased steadily, while that of physiologically active K and Cl, as well as Rb and Cs, decreased exponentially. The study showed that an adequate application of the moss transplant technique in an urban environment should consider the exposure time as a critical parameter, since particular elements are depleted in the moss at sites with high atmospheric loading of metals.

  16. Allo-allo-triploid Sphagnum × falcatulum: single individuals contain most of the Holantarctic diversity for ancestrally indicative markers.

    Science.gov (United States)

    Karlin, Eric F; Smouse, Peter E

    2017-08-01

    Allopolyploids exhibit both different levels and different patterns of genetic variation than are typical of diploids. However, scant attention has been given to the partitioning of allelic information and diversity in allopolyploids, particularly that among homeologous monoploid components of the hologenome. Sphagnum × falcatulum is a double allopolyploid peat moss that spans a considerable portion of the Holantarctic. With monoploid genomes from three ancestral species, this organism exhibits a complex evolutionary history involving serial inter-subgeneric allopolyploidizations. Studying populations from three disjunct regions [South Island (New Zealand); Tierra de Fuego archipelago (Chile, Argentina); Tasmania (Australia)], allelic information for five highly stable microsatellite markers that differed among the three (ancestral) monoploid genomes was examined. Using Shannon information and diversity measures, the holoploid information, as well as the information within and among the three component monoploid genomes, was partitioned into separate components for individuals within and among populations and regions, and those information components were then converted into corresponding diversity measures. The majority (76 %) of alleles detected across these five markers are most likely to have been captured by hybridization, but the information within each of the three monoploid genomes varied, suggesting a history of recurrent allopolyploidization between ancestral species containing different levels of genetic diversity. Information within individuals, equivalent to the information among monoploid genomes (for this dataset), was relatively stable, and represented 83 % of the grand total information across the Holantarctic, with both inter-regional and inter-population diversification each accounting for about 5 % of the total information. Sphagnum × falcatulum probably inherited the great majority of its genetic diversity at these markers by reticulation

  17. Diseño de dos metodologías moleculares para la rápida identificación de aislamientos de Staphylococcus aureus resistente a meticilina asociados a la comunidad en Colombia

    OpenAIRE

    Javier Antonio Escobar; Ingrid Tatiana Gómez; Martha Johanna Murillo; Betsy Esperanza Castro; Bibiana Chavarro; Ricaurte Alejandro Márquez; Natasha Vanegas

    2012-01-01

    Introducción. Los aislamientos de Staphylococcus aureus resistente a la meticilina asociado a la comunidad (SARM-AC), están aumentando la frecuencia de infecciones en personas sanas de la comunidad y en pacientes hospitalizados. En Colombia y en la región andina estos aislamientos tienen un componente genético relacionado con el clon pandémico USA300. Objetivo. Diseñar y estandarizar dos metodologías para la diferenciación rápida de aislamientos colombianos de S. aureus resistente a la me...

  18. Estudio de actinomicetos marinos aislados de la costa central del Perú y su actividad antibacteriana frente a Staphylococcus aureus Meticilina Resistentes y Enterococcus faecalis Vancomicina Resistentes Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Jorge León

    2011-06-01

    Full Text Available Objetivos. Determinar el potencial antimicrobiano de actinomicetos marinos frente a cepas S. aureus meticilino-resistentes (MRSA y E. faecalis vancomicina-resistentes (VRE. Materiales y métodos. En dos medios de cultivo se sembraron 29 cepas de actinomicetos aislados de sedimento marino. Se evaluó la capacidad inhibitoria mediante pruebas de antagonismo in vitro para MRSA y VRE. Se procesó los extractos orgánicos de tres actinomicetos seleccionados para determinar la Concentración Mínima Inhibitoria (CMI del compuesto activo. Resultados. La mayoría de los actinomicetos aislados correspondieron a un grupo homogéneo de blanco-grisáceos (62% con buen nivel de crecimiento en agar marino. Los porcentajes inhibitorios fueron superiores a 85% para ambos patógenos con halos de inhibición mayores a 69 y 78 mm de diámetro para MRSA y VRE respectivamente. Los extractos diclorometánicos de tres de los actinomicetos aislados (I-400A, B1-T61, M10-77 mostraron gran potencial inhibitorio de ambos patógenos, siendo M10-77 la cepa de actinomiceto de mayor actividad antibiótica frente a S. aureus ATCC 43300 resistente a meticilina y E. faecalis ATCC 51299 resistente a vancomicina con una Concentración Mínima Inhibitoria (CMI de 7,9 y 31,7 μg/ mL respectivamente. El análisis filogenético de la cepa M10- 77 presenta un 99% de similaridad con la especie marina Streptomyces erythrogriseus. Conclusiones. El sedimento marino de la costa central del Perú es fuente promisorio de cepas de actinomicetos con gran capacidad de producir compuestos bioactivos capaces de inhibir patógenos tipificados como multidrogo-resistentes tales como S. aureus meticilino resistentes y E. faecalis vancomicina resistentes.Objectives. To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant Enterococcus faecalis (VRE. Materials and

  19. WATERMARK RESISTENTE EN EL DOMINIO DE LAS FRECUENCIAS DE IMÁGENES DIGITALES PARA SU AUTENTICACIÓN SEGURA MEDIANTE AUTÓMATAS CELULARES

    Directory of Open Access Journals (Sweden)

    Luz Fátima Huallpa Vargas

    2011-01-01

    Full Text Available En este trabajo se presenta el desarrollo de un procedimiento de autenticación de imágenes digitales combinando diversos métodos relacionados con watermarks (marcas de agua digitales y métodos de cifrado, con el fin de proteger los derechos de autor de imágenes digitales. Para que este procedimiento sea robusto, imperceptible y resistente a diferentes ataques intencionales o no intencionales se trabaja en el dominio de las frecuencias de la imagen utilizando la Transformada Discreta del Coseno (Discrete Cosine Transform, DCT. Para agregar mayor nivel de protección y seguridad a la imagen marcada, se cifra el mensaje insertado a partir de una clave del autor empleando el método de Autómatas Celulares. El mensaje insertado es resistente a la compresión JPEG, a los ruidos y filtros gaussiano y salt-and-pepper. La extracción del mensaje se realiza a partir de la imagen marcada para lo cual se hace uso estricto de la clave del autor para verificar la autenticidad del mismo.

  20. Tratamiento con estatinas en pacientes pediátricos con síndrome nefrótico resistente a esteroides. Reporte de dos casos

    Directory of Open Access Journals (Sweden)

    C Sánchez-García

    2017-01-01

    Full Text Available El síndrome nefrótico se define por la asociación de proteinuria, hipoalbuminemia, hiperlipidemia y edema. El 80% de los pacientes pediátricos con síndrome nefrótico primario responde a la terapia con esteroides; el 20% restante requiere asociar otros medicamentos para alcanzar la remisión (ciclofosfamida, ciclosporina. La hiperlipidemia en el síndrome nefrótico es debida tanto a un incremento en la síntesis acompañada de disminución en la eliminación de los lípidos de la sangre; siendo la causa directa de esto la proteinuria. La hiperlipidemia incrementa el riesgo cardiovascular, así como el daño glomerular. Con base en esto, la hiperlipidemia persistente en el síndrome nefrótico resistente a esteroides debe ser tratada. Los inhibidores de la 3-hidroxi-3-metilglutaril-coenzima A (HMG-CoA reductasa han demostrado efecto antiinflamatorio, inmunomodulador y antiproliferativo. Por ello el papel de las estatinas en el síndrome nefrótico va más allá de su efecto hipolipemiante. Presentamos dos casos de pacientes pediátricos con diagnóstico de síndrome nefrótico resistente a esteroides y su evolución durante el tratamiento con ciclosporina y estatinas.

  1. Primer aislamiento en Argentina de Staphylococcus aureus resistente a la meticilina adquirido en la comunidad con sensibilidad intermedia a la vancomicina y no sensibilidad a la daptomicina

    Directory of Open Access Journals (Sweden)

    Laura Errecalde

    Full Text Available Describimos el primer caso en Argentina de Staphylococcus aureus resistente a la meticilina adquirido en la comunidad con sensibilidad intermedia a la vancomicina y no sensibilidad a la daptomicina. Caso clínico: Paciente masculino, con antecedente de insuficiencia renal crónica en hemodiálisis y osteosíntesis de cadera debido a una fractura. Se internó por síndrome febril persistente luego del desplazamiento de la prótesis por un traumatismo. Se aisló de hemocultivos S. aureus resistente a la meticilina adquirido en la comunidad. Durante el tratamiento con vancomicina y daptomicina, se observó un aumento gradual de la CIM de vancomicina de 1 µg/ml (VSSA a 2 µg/ml (h-VISA y a 4 µg/ml (VISA, y la emergencia de no sensibilidad a daptomicina (CIM = 4 µg/ml. Al suspender la vancomicina y la daptomicina, la cepa revirtió al fenotipo de sensibilidad a ambas drogas. Es mandatorio evaluar por CIM la sensibilidad a vancomicina y a daptomicina intratratamiento cuando estas drogas se usan como terapia.

  2. Denitrification at two nitrogen-polluted, ombrotrophic Sphagnum bogs in Central Europe: Insights from porewater N2O-isotope profiles

    Czech Academy of Sciences Publication Activity Database

    Novák, M.; Gebauer, G.; Thoma, M.; Curik, J.; Štěpánová, M.; Jacková, I.; Buzek, F.; Bárta, J.; Santrucková, H.; Fottová, D.; Kuběna, Aleš Antonín

    2015-01-01

    Roč. 81, č. 1 (2015), s. 48-57 ISSN 0038-0717 Grant - others:GA ČR(CZ) GAP504/12/1782 Institutional support: RVO:67985556 Keywords : Denitrification * Nitrogen isotopes * Nitrous oxide * Ombrotrophic bog * Porewater * Sphagnum * Wetland * Engineering controlled terms * Meteorological problems Subject RIV: DD - Geochemistry Impact factor: 4.152, year: 2015 http://library.utia.cas.cz/separaty/2015/E/kubena-0439538.pdf

  3. Abundant Trimethylornithine Lipids and Specific Gene Sequences Are Indicative of Planctomycete Importance at the Oxic/Anoxic Interface in Sphagnum-Dominated Northern Wetlands.

    Science.gov (United States)

    Moore, Eli K; Villanueva, Laura; Hopmans, Ellen C; Rijpstra, W Irene C; Mets, Anchelique; Dedysh, Svetlana N; Sinninghe Damsté, Jaap S

    2015-09-01

    Northern wetlands make up a substantial terrestrial carbon sink and are often dominated by decay-resistant Sphagnum mosses. Recent studies have shown that planctomycetes appear to be involved in degradation of Sphagnum-derived debris. Novel trimethylornithine (TMO) lipids have recently been characterized as abundant lipids in various Sphagnum wetland planctomycete isolates, but their occurrence in the environment has not yet been confirmed. We applied a combined intact polar lipid (IPL) and molecular analysis of peat cores collected from two northern wetlands (Saxnäs Mosse [Sweden] and Obukhovskoye [Russia]) in order to investigate the preferred niche and abundance of TMO-producing planctomycetes. TMOs were present throughout the profiles of Sphagnum bogs, but their concentration peaked at the oxic/anoxic interface, which coincided with a maximum abundance of planctomycete-specific 16S rRNA gene sequences. The sequences detected at the oxic/anoxic interface were affiliated with the Isosphaera group, while sequences present in the anoxic peat layers were related to an uncultured planctomycete group. Pyrosequencing-based analysis identified Planctomycetes as the major bacterial group at the oxic/anoxic interface at the Obukhovskoye peat (54% of total 16S rRNA gene sequence reads), followed by Acidobacteria (19% reads), while in the Saxnäs Mosse peat, Acidobacteria were dominant (46%), and Planctomycetes contributed to 6% of the total reads. The detection of abundant TMO lipids in planctomycetes isolated from peat bogs and the lack of TMO production by cultures of acidobacteria suggest that planctomycetes are the producers of TMOs in peat bogs. The higher accumulation of TMOs at the oxic/anoxic interface and the change in the planctomycete community with depth suggest that these IPLs could be synthesized as a response to changing redox conditions at the oxic/anoxic interface. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

    2010-02-15

    We record the distribution of {sup 137}Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as {sup 137}Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris{sup 137}Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher {sup 137}Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of {sup 137}Cs within the plants. The patterns of {sup 137}Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The {sup 137}Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between {sup 137}Cs and Rb (r = 0.89), and between {sup 137}Cs and stable Cs (r = 0.84). This suggests similarities between {sup 137}Cs and Rb in uptake and relocation within the Sphagnum, but that {sup 137}Cs differs from K.

  5. The distribution of 137Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

    International Nuclear Information System (INIS)

    Vinichuk, M.; Johanson, K.J.; Rydin, H.; Rosen, K.

    2010-01-01

    We record the distribution of 137 Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as 137 Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris 137 Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher 137 Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of 137 Cs within the plants. The patterns of 137 Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The 137 Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between 137 Cs and Rb (r = 0.89), and between 137 Cs and stable Cs (r = 0.84). This suggests similarities between 137 Cs and Rb in uptake and relocation within the Sphagnum, but that 137 Cs differs from K.

  6. Yeast communities in Sphagnum phyllosphere along the temperature-moisture ecocline in the boreal forest-swamp ecosystem and description of Candida sphagnicola sp. nov.

    Science.gov (United States)

    Kachalkin, Aleksey V; Yurkov, Andrey M

    2012-06-01

    The effects of the temperature-moisture factors on the phylloplane yeast communities inhabiting Sphagnum mosses were studied along the transition from a boreal forest to a swamp biotope at the Central Forest State Biosphere Reserve (Tver region, Russia). We tested the hypothesis that microclimatic parameters affect yeast community composition and structure even on a rather small spatial scale. Using a conventional plating technique we isolated and identified by molecular methods a total of 15 species of yeasts. Total yeast counts and species richness values did not depend on environmental factors, although yeast community composition and structure did. On average, Sphagnum in the swamp biotope supported a more evenly structured yeast community. Relative abundance of ascomycetous yeasts was significantly higher on swamp moss. Rhodotorula mucilaginosa dominated in the spruce forest and Cryptococcus magnus was more abundant in the swamp. Our study confirmed the low occurrence of tremellaceous yeasts in the Sphagnum phyllosphere. Of the few isolated ascomycetous yeast and yeast-like species, some were differentiated from hitherto known species in physiological tests and phylogenetic analyses. We describe one of them as Candida sphagnicola and designate KBP Y-3887(T) (=CBS 11774(T) = VKPM Y-3566(T) = MUCL 53590(T)) as the type strain. The new species was registered in MycoBank under MB 563443.

  7. The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

    Science.gov (United States)

    Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

    2010-02-01

    We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Flourish or flush: effects of simulated extreme rainfall events on Sphagnum-dwelling testate amoebae in a subarctic bog (Abisko, Sweden).

    Science.gov (United States)

    Tsyganov, Andrey N; Keuper, Frida; Aerts, Rien; Beyens, Louis

    2013-01-01

    Extreme precipitation events are recognised as important drivers of ecosystem responses to climate change and can considerably affect high-latitude ombrotrophic bogs. Therefore, understanding the relationships between increased rainfall and the biotic components of these ecosystems is necessary for an estimation of climate change impacts. We studied overall effects of increased magnitude, intensity and frequency of rainfall on assemblages of Sphagnum-dwelling testate amoebae in a field climate manipulation experiment located in a relatively dry subarctic bog (Abisko, Sweden). The effects of the treatment were estimated using abundance, species diversity and structure of living and empty shell assemblages of testate amoebae in living and decaying layers of Sphagnum. Our results show that increased rainfall reduced the mean abundance and species richness of living testate amoebae. Besides, the treatment affected species structure of both living and empty shell assemblages, reducing proportions of hydrophilous species. The effects are counterintuitive as increased precipitation-related substrate moisture was expected to have opposite effects on testate amoeba assemblages in relatively dry biotopes. Therefore, we conclude that other rainfall-related factors such as increased infiltration rates and frequency of environmental disturbances can also affect testate amoeba assemblages in Sphagnum and that hydrophilous species are particularly sensitive to variation in these environmental variables.

  9. Denervación renal percutánea mediante el uso de catéter con balón en pacientes con hipertensión arterial resistente

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    Isabel C. Marín-Orozco

    2015-11-01

    El objetivo del presente reporte es describir detalladamente dos casos de hipertensión arterial resistente, tratados mediante ablación con radiofrecuencia con el nuevo dispositivo Vessix® de la compañía Boston Scientific.

  10. Caracterización morfológica y contenido de almidón resistente y disponible en bananos (Musa sapientum exportables del Ecuador

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    Edison Omar Martínez-Mora

    2015-10-01

    Full Text Available Introducción: La investigación tuvo como objetivo fundamental, la caracterización morfológica del almidón nativo de banano (Musa sapientum, contenido en almidón resistente (AR y disponible (AD, de las variedades de banano de exportación: Cavendish (AC, Filipino (AF, Orito (AO y Valery (AV.Material y Métodos: Se determinó tamaño y forma del gránulo de almidón a través de microscopia electrónica de barrido. La cuantificación del AR por medición de su fracción no hidrolizada, luego de un ataque de pepsina, y para la fracción del AD un ataque de amilasa pancreática a la fracción no hidrolizada. Se midió la absorbancia de las dos soluciones de AR y AD a 510nm contra el blanco del reactivo.Resultados: El tamaño de los gránulos de almidón de: AF, AV y AC fueron en promedio 28μm y para el AO, de 35μm aproximadamente. La forma que predominó fue la oval esférica. El contenido de AR y AD estuvo en el rango de 49 a 58,5% y de 41 a 50%, respectivamente.Conclusiones: El almidón resistente, análogo de la fibra y útil en la nutrición humana, se presentó en valores importantes en las muestras de las diferentes variedades de banano exportable del Ecuador, alrededor del 54%. Según los resultados, el almidón de banano de las variedades estudiadas puede ser incorporado en la elaboración de alimentos que demanden características funcionales, principalmente por su alto contenido en almidón resistente.

  11. Superfícies do ambiente hospitalar como possíveis reservatórios de bactérias resistentes: uma revisão Superficies inanimadas del ambiente hospitalario como posibles reservorios de bacterias resistentes: una revisión Surfaces of the hospital environment as possible deposits of resistant bacteria: a review

    Directory of Open Access Journals (Sweden)

    Adriana Cristina de Oliveira

    2010-12-01

    Full Text Available O principal objetivo deste estudo é identificar, na literatura, artigos sobre a ocorrência de contaminação das superfícies inanimadas e uma possível disseminação de bactérias resistentes no ambiente hospitalar. Realizou-se um levantamento bibliográfico de artigos publicados nas bases de dados LILACS, MEDLINE, Science Direct, SCOPUS e ISI Web of Knowledge, entre 2000 e 2008. Foram selecionados e analisados vinte e um artigos. Nos estudos analisados, realçou-se a presença de bactérias em monitores, grades de cama, mesas, torneiras, telefones, teclados de computador e outros objetos. Houve predominância de Staphylococcus aureus resistente à meticilina, Clostridium difficile, Acine-to-bacter baumannii e Enterococcus resistentes à vancomicina, sendo fator preditivo a ocupação prévia por pacientes colonizados por tais microrganismos. Verificou-se semelhança entre as cepas isoladas de pacientes colonizados e/ou infectados e as cepas do ambiente por tipificação molecular. Essas evidências reforçam a necessidade de conhecimento e controle de fontes de patógenos no ambiente hospitalar.Se objetivó identificar en la literatura artículos sobre la ocurrencia de contaminación de superficies inanimadas y la posible diseminación de bacterias resistentes en el ambiente hospitalario. Se realizó una investigación bibliográfica en las bases de datos LLILACS, MEDLINE, Science Direct, SCOPUS e ISI Web of Knowledge acerca de artículos publicados entre 2000 y 2008. Fueron seleccionados veintiún artículos. En los estudios analizados, se puso de manifiesto la presencia de bacterias en monitores, barandas de camas, mesas, canillas, teléfonos, teclados de computadora y otras. Existió predominancia de Staphylococcus aureus resistente a la meticilina, Clostridium difficile, Acinetobacter baumannii y Enterococcus resistentes a la vancomicina, resultando como factor predictivo el uso previo por parte de pacientes colonizados por tales

  12. Phenolic compounds, methylxanthines and antioxidant activity in cocoa mass and chocolates produced from "witch broom disease" resistant and non resistant cocoa cultivars Compostos fenólicos, metilxantinas e atividade antioxidante em massa de cacau e chocolates produzidos a partir de cultivares resistentes e não resistentes a "vassoura de bruxa"

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    Paula Bacelar Leite

    2013-06-01

    Full Text Available The "witch broom disease" caused by the fungus called Moniliophthora perniciosa is one of the most important cocoa diseases in Latin America, causing around 70% production reduction in the southern Bahia. In attempt to solve the problem, many cultivars resistant to the disease have been recommended to farmers. On the other hand, the chocolate flavour is composed by many compounds whose formation depends on the genetic background, environment where cocoa is grown and processing operations. Therefore, this work aimed at determining the monomeric phenolic compounds, methylxanthines and antioxidant activity of cocoa mass and dark chocolate from cocoa cultivars resistant to "witch broom disease" and non resistant to the disease. The total phenolic compounds in cocoa mass did not vary among cultivars with values ranging from 23.95mg g-1 to 25.03mg g-1. Chocolates made from non resistant cultivars showed higher total phenolic compounds (19.11mg g-1 than SR162 and PH16 with 16.08mg g-1 and 15.46mg g-1, respectively. Epicatechin had higher content than catechin and the levels of these two compounds were higher in SR162. There were significant differences among samples of cocoa mass analyzed for caffeine. Chocolate made from SR162 had the highest amount of monomeric compounds due to its high concentration of catechin and epicatechin. The chocolate sample with the highest antioxidant activity was the SR162, followed by non resistant blend and PH16, showing relationship between the antioxidant activity and monomeric phenolics content.A "vassoura bruxa" causada pelo fungo Moniliophthora perniciosa, é uma das doenças mais importantes do cacau na América Latina, provocando uma redução de cerca de 70% na produção das amêndoas na Bahia. Para tentar resolver o problema, muitos cultivares resistentes à enfermidade têm sido recomendados para os agricultores. Por outro lado, as características do chocolate são oriundas de várias substâncias, cuja forma

  13. Diseño de dos metodologías moleculares para la rápida identificación de aislamientos de Staphylococcus aureus resistente a meticilina asociados a la comunidad en Colombia

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    Javier Antonio Escobar

    2012-06-01

    Full Text Available Introducción. Los aislamientos de Staphylococcus aureus resistente a la meticilina asociado a la comunidad (SARM-AC, están aumentando la frecuencia de infecciones en personas sanas de la comunidad y en pacientes hospitalizados. En Colombia y en la región andina estos aislamientos tienen un componente genético relacionado con el clon pandémico USA300. Objetivo. Diseñar y estandarizar dos metodologías para la diferenciación rápida de aislamientos colombianos de S. aureus resistente a la meticilina asociado a la comunidad de los asociados al hospital (SARM-AH. Materiales y métodos. Se estandarizaron dos metodologías moleculares para la identificación de aislamientos de S. aureus resistente a la meticilina asociado a la comunidad. La primera se basa en la digestión diferencial con tres enzimas de restricción de los genes cinasa de carbamato (arcC y cinasa de guanilato (gmk para los tipos de secuencia 5 (ST5 y 8 (ST8, correspondientes a aislamientos de S. aureus resistente a la meticilina asociado al hospital y asociado a la comunidad, respectivamente. La segunda se basa en la amplificación por reacción en cadena de la polimerasa de cinco factores de virulencia que se encuentran de manera diferencial en estos aislamientos. Las dos metodologías fueron validadas en 237 aislamientos clínicos de S. aureus resistente a la meticilina. Resultados. Con la primera metodología se identificaron el 100 % y 93,2 % de los aislamientos de S. aureus resistente a la meticilina asociado a la comunidad y asociado al hospital, respectivamente. Con la segunda metodología se identificaron correctamente los dos tipos de aislamientos. Conclusiones. Estas dos metodologías son una buena alternativa en términos de ahorro en tiempo y dinero comparadas con otras técnicas, como la electroforesis en campo pulsado y la tipificación de secuencias multilocus para la rápida identificación de aislamientos de S. aureus resistente a la meticilina asociado a la

  14. Competitividade de biótipos de capim-arroz resistente e suscetível ao quinclorac Competitiveness of echinochloa biotypes resistant and susceptible to quinclorac

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    G. Concenço

    2008-03-01

    Full Text Available Objetivou-se com este trabalho avaliar a competitividade de dois biótipos de capim-arroz, resistente e suscetível ao quinclorac, coletados em regiões orizícolas do Estado de Santa Catarina. O experimento foi instalado em ambiente protegido, e os tratamentos constaram de diferentes densidades de plantas dos biótipos de capim-arroz comprovadamente resistente (ITJ-13 e suscetível (ITJ-17 ao quinclorac, oriundos da região arrozeira de Itajaí/SC. No centro da unidade experimental, foram semeadas três sementes do biótipo de capim-arroz, considerado como o tratamento da unidade experimental. Na periferia foram semeadas dez sementes do biótipo oposto ao do tratamento (central. Dez dias após a germinação foi efetuado o desbaste, deixando-se apenas uma planta no centro da unidade experimental e um número variável de plantas do biótipo oposto, de acordo com o tratamento (0, 1, 2, 3, 4 ou 5 plantas por vaso. O delineamento experimental utilizado foi o completamente casualizado, em esquema fatorial 2 x 6, com quatro repetições. Aos 40 dias após a emergência, foram avaliados altura de plantas, número de afilhos e de folhas, área foliar, massa fresca e seca e conteúdo de água de colmos e folhas. Os dados foram analisados pelo teste F, sendo efetuado teste de Duncan para comparar o efeito de densidade de plantas e teste da Diferença Mínima Significativa (DMS para avaliar diferenças entre os biótipos resistente e suscetível, além de correlação linear simples entre as variáveis avaliadas. Nas análises, utilizou-se o nível de 5% de probabilidade. Os biótipos estudados de capim-arroz resistente e suscetível ao quinclorac são similares quando sob alta intensidade de competição, com vantagem em algumas variáveis para o biótipo suscetível sob baixa ou moderada intensidade competitiva.The objective of this research was to evaluate the competitive potential of two Echinochloa sp. biotypes, resistant and susceptible to

  15. Tratamiento con caspofungina de endocarditis por Candida tropicalis resistente a fluconazol Treatment with caspofungin of Candida tropicalis endocarditis resistant to fluconazol

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    Marcelo del Castillo

    2004-04-01

    Full Text Available Las endocarditis causadas por hongos, (Candida en particular, requieren tratamiento médico-quirúrgico, siendo la anfotericina B la droga de elección. Caspofungina es una equinocandina con gran actividad sobre Candida y Aspergillus. Se presenta un paciente con una endocarditis por Candida tropicalis resistente a fluconazol tratado con caspofungina bajo un esquema de salvataje, luego de haber presentado efectos adversos por anfotericina B. El paciente tuvo respuesta microbiológica.Fungal endocarditis, in particular due to Candida species, requires medical and surgical treatment and amphotericin B is the drug of choice. Caspofungin is an echinocandin very effective against Candida and Aspergillus. We present a patient with Candida tropicalis endocarditis, fluconazol resistant, treated with caspofungin, on a compassional basis as a result of adverse effects with amphotericin B. The patient had a microbiological response.

  16. Prazosina de liberação lenta para pacientes com transtorno do estresse pós-traumático resistentes aos ISRS

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    Luiz Felipe Pagotto

    2012-01-01

    Full Text Available CONTEXTO: Prazosina, um antagonista de receptores alfa-1 adrenérgicos, é utilizada no tratamento de pesadelos e insônia relacionados com TEPT. Apesar das evidências sugerindo sua eficácia também no tratamento de sintomas gerais de TEPT, sua curta meia-vida (2-3 horas pode limitar seus efeitos terapêuticos. OBJETIVO: Descrever quatro casos de pacientes com TEPT resistentes aos inibidores de recaptação de serotonina ou de serotonina e adrenalina (terapia convencional tratados com uma apresentação de prazosina de liberação lenta. MÉTODOS: Quatro pacientes com TEPT grave, resistentes à terapia convencional, tiveram a prazosina de liberação lenta (meia-vida de 10,8 horas adicionada as suas prescrições por pelo menos três meses. Os sintomas de TEPT foram avaliados pela PCL-C e pelos itens referentes a pesadelos e insônia da CAPS, na linha de base e no final do período de observação de cada paciente. RESULTADOS: Dois pacientes mostraram melhora dos sintomas gerais de TEPT (redução de 35,7% e 11,9% nos escores da PCL-C, e três mostraram melhora de pesadelos e insônia (nos escores da CAPS. O único paciente que recebeu doses da prazosina pela manhã e ao deitar-se foi o que mostrou a maior melhora dos sintomas gerais de TEPT. CONCLUSÃO: Possivelmente, a sustentação do bloqueio da atividade noradrenérgica no sistema nervoso central promovida pela prazosina de liberação lenta durante o dia se faz necessária para a melhora de sintomas residuais de TEPT em pacientes em tratamento convencional com antidepressivos.

  17. Ebullition, Plant-Mediated Transport, and Subsurface Horizontal Water Flow Dominate Methane Transport in an Arctic Sphagnum Bog

    Science.gov (United States)

    Wehr, R. A.; McCalley, C. K.; Logan, T. A.; Chanton, J.; Crill, P. M.; Rich, V. I.; Saleska, S. R.

    2017-12-01

    Emission of the greenhouse gas methane from wetlands is of prime concern in the prediction of climate change - especially emission associated with thawing permafrost, which may drive a positive feedback loop of emission and warming. In addition to the biochemistry of methane production and consumption, wetland methane emission depends critically on the transport mechanisms by which methane moves through and out of the ecosystem. We therefore developed a model of methane biochemistry and transport for a sphagnum bog representing an intermediate permafrost thaw stage in Stordalen Mire, Sweden. In order to simultaneously reproduce measured profiles of both the concentrations and isotopic compositions of both methane and carbon dioxide in the peat pore water (Fig. 1) - as well as the surface methane emission - it was necessary for the model to include ebullition, plant-mediated transport via aerenchyma, and subsurface horizontal water flow. Diffusion of gas through the pore water was relatively unimportant. As a result, 90% of the produced methane escaped the wetland rather than being consumed by methanotrophic organisms in the near-surface pore water. Our model provides a comprehensive picture of methane emission from this bog site by quantifying the vertical profiles of: acetoclastic methanogenesis, hydrogenotrophic methanogenesis, methane oxidation, aerobic respiration, ebullition, plant-mediated transport, subsurface horizontal water flow, and diffusion.

  18. Microform-related community patterns of methane-cycling microbes in boreal Sphagnum bogs are site specific.

    Science.gov (United States)

    Juottonen, Heli; Kotiaho, Mirkka; Robinson, Devin; Merilä, Päivi; Fritze, Hannu; Tuittila, Eeva-Stiina

    2015-09-01

    Vegetation and water table are important regulators of methane emission in peatlands. Microform variation encompasses these factors in small-scale topographic gradients of dry hummocks, intermediate lawns and wet hollows. We examined methane production and oxidization among microforms in four boreal bogs that showed more variation of vegetation within a bog with microform than between the bogs. Potential methane production was low and differed among bogs but not consistently with microform. Methane oxidation followed water table position with microform, showing higher rates closer to surface in lawns and hollows than in hummocks. Methanogen community, analysed by mcrA terminal restriction fragment length polymorphism and dominated by Methanoregulaceae or 'Methanoflorentaceae', varied strongly with bog. The extent of microform-related variation of methanogens depended on the bog. Methanotrophs identified as Methylocystis spp. in pmoA denaturing gradient gel electrophoresis similarly showed effect of bog, and microform patterns were stronger within individual bogs. Our results suggest that methane-cycling microbes in boreal Sphagnum bogs with seemingly uniform environmental conditions may show strong site-dependent variation. The bog-intrinsic factor may be related to carbon availability but contrary to expectations appears to be unrelated to current surface vegetation, calling attention to the origin of carbon substrates for microbes in bogs. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. The rare peat moss Sphagnum wulfianum (Sphagnaceae) did not survive the last glacial period in northern European refugia.

    Science.gov (United States)

    Kyrkjeeide, Magni Olsen; Hassel, Kristian; Flatberg, Kjell I; Stenøien, Hans K

    2012-04-01

    Organisms may survive unfavorable conditions either by moving to more favorable areas by means of dispersal or by adapting to stressful environments. Pleistocene glacial periods represent extremely unfavorable conditions for the majority of life forms, especially sessile organisms. Many studies have revealed placements of refugial areas and postglacial colonization patterns of seed plants, but little is still known about areas of long-term survival and historical migration routes of bryophytes. Given overall differences in stress tolerance between seed plants and bryophytes, it is of interest to know whether bryophytes have survived periods of extreme climatic conditions better then seed plants in northern areas. The haploid and rarely spore-producing peat moss Sphagnum wulfianum is mostly found in areas that were covered by ice during the last glacial maximum. Twelve microsatellite markers were amplified from 43 populations (367 shoots) of this species, and data were analyzed using population genetic diversity statistics, Bayesian clustering methods, and coalescence-based inference tools to estimate historical and demographic parameters. Genetic diversity within populations was low, but populations were highly differentiated, with two main genetic clusters being recognized. The two main genetic groups have diverged quite recently in the Holocene, and the pattern of genetic variability and structuring gives no support for survival in Scandinavian refugia during the last glacial period in this species. The dispersal ability of this plant thus seems surprisingly high despite its infrequent spore production.

  20. Genotoxic effect of Pb and Cd on in vitro cultures of Sphagnum palustre: An evaluation by ISSR markers.

    Science.gov (United States)

    Sorrentino, Maria Cristina; Capozzi, Fiore; Giordano, Simonetta; Spagnuolo, Valeria

    2017-08-01

    In the present work, the genotoxic effect of cadmium and lead supplied in a laboratory trial, was investigated for the first time in the moss Sphagnum palustre, by ISSR molecular markers. A total of 169 reproducible bands were obtained with 12 primers, ten of which gave polymorphisms (i.e., appearance/disappearance of bands), indicating a clear genotoxic effect induced by the metals. Both metals induced a decrease of the genome template stability in a dose dependent manner. At concentration >10 -5 Cd also induced a general toxic effect in S. palustre, leading to chlorophyll degradation and moss death. Moreover, we followed the fate of supplied heavy metals into the moss tissue by SEM-EDX to see if they entered the cells. SEM-EDX observations on moss cultures treated with equimolar concentrations of the two metals showed that most Pb precipitated in form of particles on moss surface, while Cd did not aggregate in particles and was not found on moss surface. In light of these findings, we concluded that probably Pb induced a genotoxic effect at lower intracellular concentrations than Cd. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Project CLIMPEAT - Influence of global warming and drought on the carbon sequestration and biodiversity of Sphagnum peatlands

    Science.gov (United States)

    Lamentowicz, M.; Buttler, A.; Mitchell, E. A. D.; Chojnicki, B.; Słowińska, S.; Słowiński, M.

    2012-04-01

    Northern peatlands represent a globally significant pool of carbon and are subject to the highest rates of climate warming, and most of these peatlands are in continental settings. However, it is unclear if how fast peatlands respond to past and present changes in temperature and surface moisture in continental vs. oceanic climate settings. The CLIMPEAT project brings together scientists from Poland and Switzerland. Our goal is to assess the past and present vulnerability to climate change of Sphagnum peatland plant and microbial communities, peat organic matter transformations and carbon sequestration using a combination of field and mesocosm experiments simulating warming and water table changes and palaeoecological studies. Warming will be achieved using ITEX-type "Open-Top Chambers". The field studies are conducted in Poland, at the limit between oceanic and continental climates, and are part of a network of projects also including field experiments in the French Jura (sub-oceanic) and in Siberia (continental). We will calibrate the response of key biological (plants, testate amoebae) and geochemical (isotopic composition of organic compounds, organic matter changes) proxies to warming and water table changes and use these proxies to reconstruct climate changes during the last 1000 years.

  2. Manejo de capim pé-de-galinha em lavouras de soja transgênica resistente ao glifosato Management of goose grass on transgenic soybean, resistant to glyphosate

    Directory of Open Access Journals (Sweden)

    André da Rosa Ulguim

    2013-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a resistência de capim pé-de-galinha (Eleusine indica ao glifosato, em lavouras de soja transgênica; avaliar o efeito de aplicações de glifosato em diferentes estádios de desenvolvimento; identificar práticas agronômicas associadas à seleção de biótipos resistentes; e avaliar a eficiência dos herbicidas cletodim, fluazifope-P-butílico, clomazona, glufosinato de amônio e glifosato nas plantas resistentes. Plantas escapes ao tratamento com glifosato foram coletadas em 24 propriedades, no Rio Grande do Sul. As plantas foram cultivadas em casa de vegetação, tendo-se avaliado a sua resistência ao glifosato. Os acessos resistentes foram selecionados e avaliados quanto ao efeito da aplicação do glifosato em diferentes estádios de crescimento e quanto à sensibilidade aos herbicidas. Foi aplicado um questionário aos produtores para identificação das práticas agronômicas associadas às falhas no controle. O controle de E. indica pelo glifosato é mais efetivo com a aplicação em estádios iniciais de desenvolvimento. Práticas agronômicas, como uso contínuo de baixas doses do herbicida, aplicação em estádios de desenvolvimento avançados das plantas daninhas (mais de um afilho e a ausência de rotação de culturas foram relacionadas às falhas de controle observadas. Os herbicidas cletodim, fluazifope-P-butílico e glufosinato de amônio são alternativas eficientes para o controle de E. indica.The objective of this work was to evaluate the resistance of goose grass (Eleusine indica to glyphosate application in transgenic soybean crops; evaluate the effect of glyphosate applications in different growth stages; identify the main agronomic practices associated with the selection of resistant biotypes; and evaluate the effect of the herbicides clethodim, fluazifop-p-butyl, clomazone, glufosinate ammonium, and glyphosate on resistant plants. Plants that survived glyphosate application

  3. Detección de cepas de Neisseria meningitidis resistentes a rifampicina en el Uruguay Detection of rifampicin-resistant strains of Neisseria meningitidis in Uruguay

    Directory of Open Access Journals (Sweden)

    Gabriel Pérez Giffoni

    2011-12-01

    Full Text Available El objetivo de este trabajo fue caracterizar fenotípica y genotípicamente dos aislamientos de Neisseria meningitidis resistentes a rifampicina relacionados con dos eventos independientes de transmisión de enfermedad meningocócica grave que se presentaron en septiembre y octubre de 2010 en Montevideo, Uruguay. Se revisó también la base de datos de la vigilancia nacional de resistencia a los antimicrobianos de los últimos 10 años, para estimar la frecuencia de la particularidad de los meningococos caracterizados. La resistencia a rifampicina se estudió por el método epsilométrico. El serotipo y serosubtipo de los aislamientos se determinaron por ELISA y la caracterización genotípica se realizó por digestión del ADN con NheI y electroforesis en gel con campo pulsátil. Ambos aislamientos eran idénticos, B:2a:P1.5, y su fenotipo no figuraba en la colección de 408 cepas de N. meningitidis aisladas en el Uruguay en los últimos 10 años, con la excepción de dos aislamientos sensibles a rifampicina. Los dos aislamientos estudiados también compartían un pulsotipo único, diferente del de otros dos aislamientos resistentes a rifampicina obtenidos en 2003 y 2007. Por lo tanto, ambos eventos de transmisión fueron causados por una única cepa resistente a rifampicina, que podría haberse introducido al país desde otras regiones o haberse originado por un cambio del serogrupo C al B, como producto de la presión selectiva ejercida por vacunas administradas a la población. Es necesario mantener y extremar la vigilancia. No obstante, en vista de que hasta el momento este tipo de hallazgo ha sido esporádico, no se justifica cambiar el fármaco antimicrobiano que se administra a los contactos para la profilaxis, a menos que se identifique un caso secundario.The objective of this study was to characterize the phenotype and genotype of two isolates of rifampicin-resistant Neisseria meningitidis associated with two independent events

  4. Growing season variability of net ecosystem CO2 exchange and evapotranspiration of a sphagnum mire in the broad-leaved forest zone of European Russia

    International Nuclear Information System (INIS)

    Olchev, A; Volkova, E; Karataeva, T; Novenko, E

    2013-01-01

    The spatial and temporal variability of net ecosystem exchange (NEE) of CO 2 and evapotranspiration (ET) of a karst-hole sphagnum peat mire situated at the boundary between broad-leaved and forest–steppe zones in the central part of European Russia in the Tula region was described using results from field measurements. NEE and ET were measured using a portable measuring system consisting of a transparent ventilated chamber combined with an infrared CO 2 /H 2 O analyzer, LI-840A (Li-Cor, USA) along a transect from the southern peripheral part of the mire to its center under sunny clear-sky weather conditions in the period from May to September of 2012 and in May 2013. The results of the field measurements showed significant spatial and temporal variability of NEE and ET that was mainly influenced by incoming solar radiation and ground water level. The seasonal patterns of NEE and ET within the mire were quite different. During the entire growing season the central part of the mire was a sink of CO 2 for the atmosphere. NEE reached maximal values in June–July (−6.8 ± 4.2 μmol m −2 s −1 ). The southern peripheral part of the mire, due to strong shading by the surrounding forest, was a sink of CO 2 for the atmosphere in June–July only. ET reached maximal values in the well-lighted central parts of the mire in May (0.34 ± 0.20 mm h −1 ) mainly because of high air and surface temperatures and the very wet upper peat horizon and sphagnum moss. Herbaceous species made the maximum contribution to the total gross primary production (GPP) in both the central and the peripheral parts of the mire. The contribution of sphagnum to the total GPP of these plant communities was relatively small and ranged on sunny days of July–August from −1.1 ± 1.1 mgC g −1 of dry weight (DW) per hour in the peripheral zone of the mire to −0.6 ± 0.2 mgC g −1 DW h −1 at the mire center. The sphagnum layer made the maximum contribution to total ET at the mire center (0

  5. The use of Sphagnum recurvum Pal. Beauv. as biological tests for determination of the level of pollution with fluorine compounds and sulphur dioxide in the environment

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    Maria Świeboda

    2014-01-01

    Full Text Available The green parts of the peat moss Sphagnum recurvum Pal. Beauv. were used as a biological test to evaluate the pollution level of the natural environment in the region of the aluminium works "Skawina" (Southern Poland with fluorine compounds and sulphur dioxide. The moss samples were placed in nylon nets and exposed to the polluted air for 6 weeks, then the fluorine and sulphur content in them was determined. The results demonstrated the usefulness of this method for the purpose of establishing the range of influence of the emitted industrial pollution.

  6. DNA molecular markers in mosses and their use for the characterization of a Sphagnum palustre clone, for its exploitation as a passive contaminant sensor

    OpenAIRE

    Crespo Pardo, David

    2015-01-01

    The control of the air quality is often assessed by the use of terrestrial mosses. However, due to the lack of standardization in the used techniques, the comparison between the available studies is difficult. My PhD thesis was related to the European project FP7-Mossclone. The aim of this project is the development of a standardized method for biomonitoring the level of atmospheric pollution through the use of a devitalized moss clone of Sphagnum palustre, using the moss bags technique. My p...

  7. Methylocapsa acidiphila gen. nov., sp. nov., a novel methane-oxidizing and dinitrogen-fixing acidophilic bacterium from Sphagnum bog.

    Science.gov (United States)

    Dedysh, Svetlana N; Khmelenina, Valentina N; Suzina, Natalia E; Trotsenko, Yuri A; Semrau, Jeremy D; Liesack, Werner; Tiedje, James M

    2002-01-01

    A novel genus and species, Methylocapsa acidiphila gen. nov., sp. nov., are proposed for a methane-oxidizing bacterium isolated from an acidic Sphagnum peat bog. This bacterium, designated strain B2T, represents aerobic, gram-negative, colourless, non-motile, curved coccoids that form conglomerates covered by an extracellular polysaccharide matrix. The cells use methane and methanol as sole sources of carbon and energy and utilize the serine pathway for carbon assimilation. Strain B2T is a moderately acidophilic organism with growth between pH 4.2 and 7.2 and at temperatures from 10 to 30 degrees C. The cells possess a well-developed system of intracytoplasmic membranes (ICM) packed in parallel on only one side of the cell membrane. This type of ICM structure represents a novel arrangement, which was termed type III. The resting cells are Azotobacter-type cysts. Strain B2T is capable of atmospheric nitrogen fixation; it possesses particulate methane monooxygenase and does not express soluble methane monooxygenase. The major phospholipid fatty acid is 18:1omega7c and the major phospholipids are phosphatidylglycerols. The G+C content of the DNA is 63.1 mol%. This bacterium belongs to the alpha-subclass of the Proteobacteria and is most closely related to the acidophilic methanotroph Methylocella palustris KT (97.3% 16S rDNA sequence similarity). However, the DNA-DNA hybridization value between strain B2T and Methylocella palustris K(T) is only 7%. Thus, strain B2T is proposed to comprise a novel genus and species, Methylocapsa acidiphila gen. nov., sp. nov. Strain B2T (= DSM 13967T = NCIMB 13765T) is the type strain.

  8. Changes in the aquatic moss Sphagnum denticulatum Brid. population abundance in a softwater lake over a period of three years

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    Józef Szmeja

    2011-01-01

    Full Text Available Changes in population abundance of submerged Sphagnum denticulatum Brid. were studied in an acidic and oligotrophic lake in NW Poland over three years. Individuals were counted in a moss carpet at a depth of 2.5 m on 4 experimental plots, 1 × 1 m each, every 30 days for 36 months using the SCUBA method. PAR intensity was seasonally variable (in winter higher than in summer. Changes in water pH, conductivity, HCO3- concentration, hydration and sediment pH were statistically insignificant (p > 0.05. In the summer of the second study year the moss carpet disappeared almost completely due to a massive bloom of filamentous green algae. Periods of growth, regression and regeneration were observed in the population. The stabilisation of population size took 24 months and followed the pattern: slight fluctuations, then rapid growth and repetition of slight fluctuations. The first stage lasted nine, the second four and the third nine months. These stages took place irrespective of seasons, temperature or PAR intensity. Each rapid increase in abundance lasted about 30 days, at PAR intensity >20% and water temperature ranging from 11 to 16oC (in winter, spring or autumn. The regression stage brought about by the algal bloom started in the second year (in summer and lasted six months (until the end of January in the third year. The population regeneration began in winter (in February, water temperature 3.0oC, PAR about 20%, ice cover 0.15 m and finished with the end of spring. The population of S. denticulatum shows a repetitive pattern of abundance variations, which is seriously disturbed in summer, especially after a warm spring, by a massive bloom of filamentous green algae.

  9. Isotope composition of bulk carbon in replicated Sphagnum peat cores from three central European high-elevation wetlands

    International Nuclear Information System (INIS)

    Novak, Martin; Zemanova, Leona; Jackova, Iva; Buzek, Frantisek; Adamova, Marie

    2009-01-01

    Several processes may contribute to systematic downcore trends in δ 13 C of bulk Sphagnum peat. Whereas changes in water availability during C assimilation may change δ 13 C values in both a negative and positive direction, other processes would always cause a uni-directional shift in δ 13 C. Selective preservation of isotopically light lignin C may lead to more negative δ 13 C values with an increasing depth and age of peat. Anthropogenic change toward lower δ 13 C of atmospheric CO 2 due to massive coal burning since the beginning of the Industrial Revolution would result in lower δ 13 C of the youngest past layers, and in higher δ 13 C of older peat layers. Emissions of low-δ 13 C methane from wetlands should result in a progressive enrichment of the residual peat substrate in the heavier isotope 13 C. Consequently, deeper peat would have higher δ 13 C. In a specific peat profile, the downcore trend in δ 13 C will be the result of an interplay between all these isotope-sensitive processes. Most Central European wetlands studied previously show a 13 C enrichment (i.e., higher δ 13 C values) with an increasing depth and age. Here we focus on sites which showed lower δ 13 C with an increasing depth and age when a single peat core was taken. Replication did not confirm this negative downcore δ 13 C shift. A positive downcore δ 13 C shift is more widespread than previously believed. We suggest that decreasing δ 13 C of atmospheric CO 2 and emissions of low-δ 13 C methane belong to the main controls of the downcore δ 13 C trends in young peat substrate. (author)

  10. Singulisphaera rosea sp. nov., a planctomycete from acidic Sphagnum peat, and emended description of the genus Singulisphaera.

    Science.gov (United States)

    Kulichevskaya, Irina S; Detkova, Ekaterina N; Bodelier, Paul L E; Rijpstra, W Irene C; Damsté, Jaap S Sinninghe; Dedysh, Svetlana N

    2012-01-01

    An aerobic, pink-pigmented, budding bacterium, designated strain S26(T), was isolated from an acidic Sphagnum peat bog of north-western Russia. Cells were non-motile and spherical, occurring singly, in pairs or in short chains, and were able to attach to surfaces by means of a holdfast material. Strain S26(T) was a moderately acidophilic, mesophilic organism capable of growth at pH 3.2-7.1 (optimum at pH 4.8-5.0) and at 4-33 °C (optimum at 20-26 °C). Most sugars, several organic acids and polyalcohols were the preferred growth substrates. The major fatty acids were C(16:0), C(18:1)ω9c and C(18:2)ω6c,12c. The major neutral lipids were n-C(31:9) hydrocarbon and squalene; the polar lipids were phosphatidylglycerol, phosphatidylcholine and components with an unknown structure. The DNA G+C content of strain S26(T) was 62.2 mol%. 16S rRNA gene sequence analysis showed that strain S26(T) is a member of the order Planctomycetales. Among taxonomically characterized representatives of this order, highest levels of 16S rRNA gene sequence similarity (95.1-95.2%) were observed with strains of the non-filamentous, peat-inhabiting planctomycete Singulisphaera acidiphila. Strain S26(T) could be differentiated from Singulisphaera acidiphila based on pigmentation, significant differences in substrate utilization patterns, greater tolerance of acidic conditions and the presence of C(16:1)ω9c. Based on the data presented, strain S26(T) is considered to represent a novel species of the genus Singulisphaera, for which the name Singulisphaera rosea sp. nov. is proposed; the type strain is S26(T) (=DSM 23044(T)=VKM B-2599(T)).

  11. Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China

    Directory of Open Access Journals (Sweden)

    Rong Hu

    2018-02-01

    Full Text Available Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr, copper (Cu, lead (Pb, vanadium (V, and zinc (Zn at five sampling sites (four roads and a forest park during the summer and winter of 2012. According to the relative accumulation factor (RAF and contamination factor (CF results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation (p < 0.05 between traffic volume and concentration for three heavy metals (Cr, Cu, and V in winter, whereas a significant positive correlation (p < 0.05 was observed between traffic volume and concentrations for four heavy metal elements (Cr, Pb, V, and Zn in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution.

  12. Nitrogen and sulphur deposition and the growth of Sphagnum fuscum in bogs of the Athabasca Oil Sands Region, Alberta

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    Melanie A. VILE

    2010-08-01

    Full Text Available One of the consequences of ongoing development of the oil sands reserve in the Athabasca Oil Sands Region (AOSR near Fort McMurray, Alberta, Canada (56° 39' N, 111° 13' W is an increase in emissions of nitrogen (N and sulphur (S, with an attendant increases in regional atmospheric N and S deposition. Regional land cover across northeastern Alberta is a mixture of Boreal Mixedwood, Boreal Highlands, and Subarctic areas. Peatlands occupy between 22 and 66% of these natural regions, and the land cover of bogs varies between 6.7% in the Mixedwood Region to 46% in the Subarctic Region. Ombrotrophic bog ecosystems may be especially sensitive to atmospheric deposition of N and S. Across 10 ombrotrophic bog sites in the AOSR over four years (2005– 2008, we found no evidence of elevated deposition of NH4 +-N, NO3 –-N, total inorganic nitrogen (TIN; NH4 +-N plus NO3 –-N, or SO4 2–-S, with values measured using ion exchange resin collectors averaging 0.61 ± 04, 0.20 ± 0.01, 0.81 ± 0.04, and 1.14 ± 0.06 kg ha–1 y–1, respectively. Vertical growth and net primary production of Sphagnum fuscum, an indicator of elevated deposition, did not differ consistently across sites, averaging 11.8 ± 0.2 mm y–1 and 234 ± 3.3 g m–2 y–1, respectively, over the four years. Neither vertical growth nor net primary production of S. fuscum was correlated with growing season atmospheric N or S deposition. Our data provide a valuable benchmark of background values for monitoring purposes in anticipation of increasing N and S deposition over a broader geographic region within the AOSR.

  13. Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China.

    Science.gov (United States)

    Hu, Rong; Yan, Yun; Zhou, Xiaoli; Wang, Yanan; Fang, Yanming

    2018-02-22

    Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr), copper (Cu), lead (Pb), vanadium (V), and zinc (Zn)) at five sampling sites (four roads and a forest park) during the summer and winter of 2012. According to the relative accumulation factor (RAF) and contamination factor (CF) results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation ( p heavy metals (Cr, Cu, and V) in winter, whereas a significant positive correlation ( p heavy metal elements (Cr, Pb, V, and Zn) in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution.

  14. Treatment of methicillin-resistant Staphylococcus aureus in Latin America Tratamento de Staphylococcus aureus resistente à meticilina na América Latina

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    Carlos M Luna

    2010-12-01

    Full Text Available The global spread of methicillin-resistant Staphylococcus aureus (MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin AmericaA propagação global de Staphylococcus aureus resistente à meticilina (methicillin-resistant Staphylococcus aureus - MRSA significa que se trata agora de um patógeno de interesse para a saúde pública mundial. Na América Latina, o MRSA é altamente prevalente, com a proporção de S. aureus resistente à meticilina em ascensão, no entanto os recursos para o tratamento da infecção são limitados. Embora existam várias diretrizes para o tratamento de infecções por MRSA, muitas são elaboradas para a América do Norte ou a Europa e precisam ser adaptadas para sua utilização na América Latina. Neste artigo, procuramos destacar a importância do tratamento adequado do MRSA nas unidades de saúde e na comunidade na América Latina. Apresentamos um resumo das diretrizes e dos antibióticos disponíveis, e discutimos considerações específicas para os médicos que tratam de MRSA na América Latina.

  15. Caracterização dos Genes de metalo-beta-lactamase blaNDM, blaSPM e blaIMP em Pseudomonas aeruginosa Resistentes a Carbapenens

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    Carolina Jahn

    2017-01-01

    Full Text Available Justificativa e objetivo: P. aeruginosa é responsável por causar grande variedade de infecções agudas e crônicas. A resistência aos carbapenêmicos está se tornando um problema terapêutico mundial e a produção de metalo-beta-lactamases (MBL tem surgido como um dos mecanismos responsáveis por esta resistência. Objetivou-se identificar as cepas produtoras de MBL e verificar a presença dos genes codificador blaNDM, blaSPM e blaIMP em isolados de P. aeruginosa resistentes aos carbapenens. Métodos: Foram analisadas 16 cepas de P. aeruginosa, isoladas de diferentes sítios de indivíduos atendidos pelo Hospital do Vale do Rio Pardo-RS, no período de março 2014 a fevereiro de 2015. A identificação bioquímica foi realizada segundo protocolo da ANVISA e o antibiograma pelo método de ágar difusão em disco. A triagem fenotípica foi feita pelo teste modificado de aproximação de discos utilizando o EDTA como inibidor e a presença dos genes através da técnica de reação em cadeia da polimerase. Resultados: O setor clínico com maior prevalência de isolamento de P. aeruginosa resistente aos carbapenens é a unidade de terapia intensiva (50%. Em relação aos espécimes clínicos, 62,5% dos isolados foram identificados no trato respiratório inferior. Através do teste fenotípico, 50% das amostras analisadas mostraram ser produtora da enzima MBL. Através da técnica de reação em cadeia da polimerase foi possível identificar a presença de um dos três genes propostos, sendo eles blaSPM. Conclusão: Os isolados de P. aeruginosa mostraram serem produtores de MBL e apresentaram o gene de resistência blaSPM nesta espécie no interior do Rio Grande do Sul. Palavras Chaves: Pseudomonas aeruginosa; metalo-beta-lactamases; blaNDM, blaIMP, e blaSPM .

  16. Cepas de Campylobacter jejuni resistentes a quinolonas aisladas de humanos, gallinas y pollos Quinolone resistant Campylobacter jejuni strains isolated from humans and from poultry

    Directory of Open Access Journals (Sweden)

    Rodolfo Notario

    2011-08-01

    Full Text Available Se compararon 8 aislamientos de Campylobacter jejuni provenientes de humanos con enfermedad diarreica aguda, con 23 aislamientos de cloaca de gallinas y pollos obtenidos de zonas próximas a la ciudad de Rosario, todos resistentes a la ciprofloxacina. Las muestras se sembraron en agar selectivo y se incubaron en microaerofilia a 42 °C. Las colonias se identificaron con el método tradicional. Los aislamientos se conservaron a -70 °C en caldo cerebro corazón con 17% v/v de glicerina. La clonalidad se determinó por RAPD-PCR, utilizando el primer 1254 (Stern NJ. Se interpretaron los aislamientos como clones distintos cuando diferían en una banda de amplificación. Se obtuvieron 5 clones diferentes. Los patrones I, II y V fueron aislados en criaderos industriales de pollos y en humanos (el II también en un establecimiento de gallinas ponedoras de huevos. En un gallinero familiar se obtuvo el patrón I. El patrón III sólo se obtuvo de humanos. El patrón IV se halló en uno de los criaderos pero no en humanos. Se pudo determinar que 93.5% de las cepas se aislaron tanto de animales como de humanos, por lo que se considera posible que la colonización de criaderos con cepas resistentes a los antimicrobianos pudiera ser el origen de la infección de humanos.Eight quinolone resistant Campylobacter jejuni strains isolated from humans with diarrheal disease were compared with 23 isolates from chicken and from laying hens. Samples were cultured on selective agar in microaerophilia, identified by conventional tests, and conserved in 17% glycerol at -70 °C. Clones were determined by RAPD-PCR employing the 1254 primer (Stern NJ. Five patterns were obtained. Patterns I, II, and V were found in both poultry and human isolates. Pattern I was obtained from poultry in a domestic henhouse. Pattern III was only obtained from humans whereas pattern IV was only obtained from poultry. A 95.3% of clones were found in both, humans and poultry. According to these

  17. Tuberculose multi-resistente. A propósito de um caso clínico de reinfeção exógena adquirida no meio prisional

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    José Leon Bernardo

    1998-05-01

    Full Text Available RESUMO: Os autores descrevem um caso clinic de tuberculose multi-resistente num doente recluse, toxicodependente e com SIDA que se encontrava sob terapêutiea antibacilar em virtude de anterior episodin de tuberculose “sendivel”.Comentam alguns aspectos relacionadus com o diagnostic, tratamento e evoução exógena por estirpe multi-resistente.Em conclusão, us autores salientam o interesse do DNA “fingerprinting” no diagnostic e epidemiologia da tuberculose multi-resistente e a necessidade de implementação de um efectivo programa de luta contra a tuberculose multi-resistente na comunidade prisional.REV PORT PNEUMOL 1998; IV (3: 319-325 ARSTRACT: A case of multidrug-resistant tuberculosis in a drug-addicted and jailed patient with AIDS is reported. The patient was in anti-tuberculosis therapy, because a question of ongoing “sensitive” tuberculosis.The authors comment some aspects of the clinical management of the patient. Exogenous reinfection with a multidrug-resistant strain was convincelly demonstrated with DNA fingerprinting.The relevance of DNA fingerprinting in the diagnosis and epidemiology of multidrug-resistant tuberculosis is emphasized and the reformulation of the anti-tuberculosis programme in the prisional setting is warranted, in the face of ongoing transmissionREV PORT PNEUMOL 1998; IV (3: 319-325 Palavras-chave: Tuberculose multirresistente, RFLP, Key-words: Multidrug-resistant tuberculosis (MDR-TB, RELP

  18. EVALUACIÓN DEL DISEÑO DE UNA PEQUEÑA MESA VIBRATORIA PARA ENSAYOS EN INGENIERÍA SISMO-RESISTENTE

    Directory of Open Access Journals (Sweden)

    Julián Carrillo

    2013-01-01

    Full Text Available Las consecuencias catastróficas de los sismos han incentivado la realización de estudios experimentales para mitigar los efectos de los sismos sobre las estructuras. En el artículo se presenta la evaluación de los diseños mecánico, neumático, estructural, de control y de adquisición de datos, de una pequeña mesa vibratoria uniaxial para ensayos de estructuras a escala reducida. Inicialmente se eligieron los elementos mecánicos que permiten el movimiento de la mesa. Luego se validó el desempeño del sistema a partir de herramientas de simulación. Finalmente se estudió la automatización de la mesa por medio de un control con sistema de lazo abierto, implementado en un micro-controlador. La mesa vibratoria propuesta es una herramienta versátil y económica para realizar pruebas experimentales orientadas al análisis y diseño de estructuras sometidas a eventos sísmicos. El dispositivo propuesto promoverá la investigación no sólo en nuevos materiales, sino en diseño y rehabilitación de viviendas, edificios y puentes sismo-resistentes.

  19. Plantas transgênicas resistentes aos herbicidas: situação e perspectivas Resistant transgenic plants to the herbicide: situation and perspectives

    Directory of Open Access Journals (Sweden)

    Patrícia Andréa Monquero

    2005-01-01

    Full Text Available Organismos geneticamente modificados (OGMs ou transgênicos podem ser plantas, animais ou microorganismos que tiveram no seu material genético a introdução de DNA proveniente de outro organismo. Em alguns casos, esse organismo poder ser outro individuo da mesma espécie, ou o mais comum, de outra espécie com o qual não há cruzamento natural. O uso dessa técnica no melhoramento de plantas permitirá aumentar a produção, reduzir perdas na pós-colheita, obter culturas mais tolerantes ao estresse ambiental, obter culturas que usem mais eficientemente nitrogênio e fósforo; aumentar o valor nutricional dos alimentos; obter plantas resistentes a herbicidas, pragas e ou doenças; desenvolver alternativas para indústrias como as de combustíveis e farmacêuticas. Alguns consumidores acreditam que OGM não é natural e que o melhoramento convencional é melhor, pois segue os princípios naturais de seleção ou usa mutações naturais. Entretanto, é possível e muito comum obter combinações indesejáveis de genes através do melhoramento tradicional. Com relação a culturas resistentes a herbicidas, várias preocupações podem ser destacadas. Essas incluem: (a deriva de herbicida para vegetação suscetível vizinha à cultura tolerante; (b cultura resistente ao herbicida pode tornar-se planta daninha de difícil controle; (c uso ilegal de sementes; (d reação pública negativa à engenharia genética; (e escape de genes para espécies nativas e (f seleção de biótipos resistentes ou de espécies tolerantes ao herbicida utilizado. A geração dos organismos geneticamente modificados tem sido alvo de polêmica e discussão nos diversos segmentos da sociedade. Porém, não se deve generalizar o uso dos transgênicos, pois cada um deve ser analisado quanto às suas vantagens, desvantagens e contribuição à melhoria da qualidade de vida.Genetically modified organisms (GMOs or transgenic may be plants, animals or microorganisms that have

  20. Tilt teste no diagnóstico diferencial da "epilepsia" resistente ao tratamento Tilt table test in the differential diagnosis of refractory "epilepsy"

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    Renata Rodrigues Teixeira de Castro

    2006-11-01

    Full Text Available A epilepsia é uma das causas mais freqüentes de distúrbios neurológicos em adultos jovens. Relatamos um caso em que uma paciente conviveu durante doze anos com o diagnóstico de epilepsia resistente ao tratamento, quando, na verdade, a causa de seus sintomas pôde ser encontrada com a realização do teste de inclinação (tilt teste. O cardiologista deve estar alerta para o possível diagnóstico de síncope neurocardiogênica em pacientes previamente diagnosticados como portadores de epilepsia, especialmente naqueles com difícil controle terapêutico.Epilepsy is one of the most frequent causes of neurological disorders in young adults. We report the case of a patient who lived with the diagnosis of refractory epilepsy for twelve years, when actually the cause of the symptoms could be found with the performance of a tilt table test. Cardiologists should be aware of the possible diagnosis of neurocardiogenic syncope in patients previously diagnosed with epilepsy, especially in those with difficult therapeutic control.

  1. Factores psicológicos, demográficos y sociales asociados al estrés y a la Personalidad Resistente en adultos mayores

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    Zoila Edith Hernández Zamora

    2009-01-01

    Full Text Available Se muestran los resultados encontrados con relación al constructo Personalidad Resistente (PR y los niveles de estrés en una muestra de 102 adultos mayores. La mayoría de los y las participantes tienen un nivel alto de PR y ninguno resultó con un nivel bajo en este constructo. Las variables asociadas significativamente con una PR alta son: sexo, independencia, escolaridad, autopercepción de salud y repercusión en el estado de ánimo de sus enfermedades. Las variables asociadas con un nivel de estrés bajo son: satisfacción con el apoyo familiar y de amistades, escolaridad, número de enfermedades, autopercepción de salud, influencia en el estado de ánimo de sus enfermedades y estado de ánimo. Estos resultados, además, comprueban la hipótesis de que tener una PR alta está relacionado significativamente con un nivel de estrés bajo.

  2. Secuenciación genética y mutaciones cromosómicas en cepas de Mycobacterium tuberculosis resistentes a rifampicina

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    Alexander Galindo

    2000-07-01

    Full Text Available Los individuos afectados con Mycobacterium tuberculosis son más de un billon y cerca de 3,5 millones enferman anualmente en el mundo. La Organizaci6n Mundial de la Salud (OMS considera que estarnos ante una emergencia global de tuberculosis que podría provocar 200 millones de casos nuevos y 70 millones de muertes antes del 2020. Se estima que en 1998 fueron reportados 8.8 millones de casos nuevos y que fallecieron por esta causa cerca de 3 millones de personas, 6% de la mortalidad global del año, La alta incidencia en la población, la convierte en la principal causa de muerte en adultos en edad productiva, es decir de 15 a 49 años. Se considera que 80% de la población está dentro del grupo de alto riesgo que puede padecer esta enfermedad y se asume que más de 50 millones de personas están infectadas con cepas resistentes (Guerrero,1998 y Rattan 1998.

  3. Comparación de los resultados de riesgo sísmico en dos ciudades con los mismos coeficientes de diseño sismo resistente

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    Mario Andrés Salgado-Gálvez

    2015-03-01

    Full Text Available De acuerdo al Reglamento NSR-10 las ciudades de Bogotá y Medellín tienen los mismos coeficientes de diseño Aa y Av que, desde una primera lectura, indicarían el mismo nivel de amenaza sísmica. Sin embargo, la selección del período de retorno para diseño sismo resistente corresponde a una decisión arbitraria y valores iguales de amenaza en ambas ciudades corresponden a una mera coincidencia, dado que, la amenaza sísmica en cada caso se ve influenciada por entornos sismo-tectónicos totalmente diferentes. La comparación de los resultados de riesgo sísmico, desde el punto de vista físico, de ambas ciudades, permite identificar la influencia de las fuentes sismogénicas, los efectos de sitio y la vulnerabilidad física en dichos análisis.

  4. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    NARCIS (Netherlands)

    Tsyganov, A.N.; Aerts, R.; Nijs, I.; Cornelissen, J.H.C.; Beyens, L.

    2012-01-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming,

  5. Características fenotípicas da hipertensão arterial resistente na população brasileira Phenotypic characteristics of resistant hypertension in the Brazilian population

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    Ana Paula Cabral de Faria

    2013-01-01

    Full Text Available Hipertensão resistente (HAR é definida como a pressão arterial que permanece acima da meta pressórica, apesar do uso de três classes de anti-hipertensivos em doses otimizadas, sendo um deles um diurético. Além disso, são considerados também hipertensos resistentes os pacientes que usam quatro ou mais classes e possuem suas pressões controladas. Embora essa definição seja útil na categorização de um maior grupo de resistentes, visto esses dois subgrupos compartilharem alto risco cardiovascular, algumas importantes particularidades clínicas e fisiopatológicas necessitam ser mais bem avaliadas antes de resistentes controlados e não controlados pertencerem ao mesmo grupo. Foram comparadas algumas características cardiovasculares nesses dois subgrupos de hipertensos resistentes. Embora algumas semelhanças, o subgrupo HRNC apresenta fenótipos cardiovasculares com pior prognóstico como maior rigidez vascular e hipertrofia ventricular esquerda, além de função endotelial mais prejudicada e menor queda de pressão arterial no período noturno, entre outras. Frente às diferenças, o subgrupo HRNC está associado à maior risco cardiovascular, podendo ser considerado mais resistente ao tratamento anti-hipertensivo. Além da importância de melhor prevenção e tratamento da HAR com medidas de identificar precocemente os fatores de risco e otimizar a terapia farmacológica, algumas implicações clínicas devem ser consideradas na abordagem de pacientes controlados e não controlados como semelhantes ao grupo de resistentes.Resistant hypertension (RH is defined as blood pressure that remains above target in spite of the concurrent use of three or more classes of antihypertensive drugs at optimized doses (UCRH, with one of them being a diuretic. Moreover, patients whose blood pressure is controlled while using four or more antihypertensive medications are also considered controlled resistant hypertensive (CRH subjects. Although this

  6. Molecular analysis and dimorphism of azole-susceptible and resistant Candida albicans isolates Análise molecular e dimorfismo de isolados de Candida albicans suscetíveis e resistentes aos azólicos

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    Carolina Rodrigues Costa

    2011-12-01

    estudo, os efeitos de agentes antifúngicos como o fluconazol e o itraconazol sobre a formação de hifas e caracterização genotípica de isolados de C. albicans suscetíveis ou resistentes foram investigados. MÉTODOS: A produção de hifas de cinco isolados de C. albicans, sob a ação de antifúngicos foi investigada pelo cultivo da levedura em meios de crescimento e de indução de hifas. A caracterização genotípica foi realizada para 13 isolados de C. albicans pelo método de RAPD-PCR. RESULTADOS: A análise do dimorfismo mostrou que a formação de hifas foi maior nos isolados resistentes do que nos suscetíveis aos antifúngicos. O método de RAPD-PCR identificou a formação de dois diferentes grupos. No grupo A, foram agrupados quatro isolados resistentes e dois suscetíveis e no grupo B um resistente e seis suscetíveis. CONCLUSÕES: Considerando que a formação hifal foi maior em isolados resistentes na presença de azólicos, concluimos que a produção hifal está muito relacionada a suscetibilidade a estes fámacos. Estes antifúngicos podem alterar a morfologia de C. albicans em dependência da sua suscetibilidade. No método de RAPD-PCR, o encontro da maioria dos isolados resistentes classificados como pertencentes ao grupo A e suscetíveis ao grupo B demonstrou que este método apresentou um padrão semelhante entre os dois grupos, sugerindo que por este método pode ser detectado uma estreita correlação entre genótipos e amostras resistentes ao fluconazol.

  7. Response of sphagnum peatland testate amoebae to a 1-year transplantation experiment along an artificial hydrological gradient.

    Science.gov (United States)

    Marcisz, Katarzyna; Fournier, Bertrand; Gilbert, Daniel; Lamentowicz, Mariusz; Mitchell, Edward A D

    2014-05-01

    Peatland testate amoebae (TA) are well-established bioindicators for depth to water table (DWT), but effects of hydrological changes on TA communities have never been tested experimentally. We tested this in a field experiment by placing Sphagnum carpets (15 cm diameter) collected in hummock, lawn and pool microsites (origin) at three local conditions (dry, moist and wet) using trenches dug in a peatland. One series of samples was seeded with microorganism extract from all microsites. TA community were analysed at T0: 8-2008, T1: 5-2009 and T2: 8-2009. We analysed the data using conditional inference trees, principal response curves (PRC) and DWT inferred from TA communities using a transfer function used for paleoecological reconstruction. Density declined from T0 to T1 and then increased sharply by T2. Species richness, Simpson diversity and Simpson evenness were lower at T2 than at T0 and T1. Seeded communities had higher species richness in pool samples at T0. Pool samples tended to have higher density, lower species richness, Simpson diversity and Simpson Evenness than hummock and/or lawn samples until T1. In the PRC, the effect of origin was significant at T0 and T1, but the effect faded away by T2. Seeding effect was strongest at T1 and lowest vanished by T2. Local condition effect was strong but not in line with the wetness gradient at T1 but started to reflect it by T2. Likewise, TA-inferred DWT started to match the experimental conditions by T2, but more so in hummock and lawn samples than in pool samples. This study confirmed that TA responds to hydrological changes over a 1-year period. However, sensitivity of TA to hydrological fluctuations, and thus the accuracy of inferred DWT changes, was habitat specific, pool TA communities being least responsive to environmental changes. Lawns and hummocks may be thus better suited than pools for paleoecological reconstructions. This, however, contrasts with the higher prediction error and species' tolerance for

  8. Acidicapsa borealis gen. nov., sp. nov. and Acidicapsa ligni sp. nov., subdivision 1 Acidobacteria from Sphagnum peat and decaying wood.

    Science.gov (United States)

    Kulichevskaya, Irina S; Kostina, Lilia A; Valásková, Vendula; Rijpstra, W Irene C; Damsté, Jaap S Sinninghe; de Boer, Wietse; Dedysh, Svetlana N

    2012-07-01

    Two strains of subdivision 1 Acidobacteria, a pink-pigmented bacterium KA1(T) and a colourless isolate WH120(T), were obtained from acidic Sphagnum peat and wood under decay by the white-rot fungus Hyploma fasciculare, respectively. Cells of these isolates were Gram-negative-staining, non-motile, short rods, which were covered by large polysaccharide capsules and occurred singly, in pairs, or in short chains. Strains KA1(T) and WH120(T) were strictly aerobic mesophiles that grew between 10 and 33 °C, with an optimum at 22-28 °C. Both isolates developed under acidic conditions, but strain WH120(T) was more acidophilic (pH growth range 3.5-6.4; optimum, 4.0-4.5) than strain KA1(T) (pH growth range 3.5-7.3; optimum , 5.0-5.5). The preferred growth substrates were sugars. In addition, the wood-derived isolate WH120(T) grew on oxalate, lactate and xylan, while the peat-inhabiting acidobacterium strain KA1(T) utilized galacturonate, glucuronate and pectin. The major fatty acids were iso-C(15:0) and iso-C(17:1)ω8c; the cells also contained significant amounts of 13,16-dimethyl octacosanedioic acid. The quinone was MK-8. The DNA G+C contents of strains KA1(T) and WH120(T) were 54.1 and 51.7 mol%, respectively. Strains KA1(T) and WH120(T) displayed 97.8% 16S rRNA gene sequence similarity to each other. The closest recognized relatives were Acidobacterium capsulatum and Telmatobacter bradus (93.4-94.3% 16S rRNA gene sequence similarity). These species differed from strains KA1(T) and WH120(T) by their ability to grow under anoxic conditions, the absence of capsules, presence of cell motility and differing fatty acid composition. Based on these differences, the two new isolates are proposed as representing a novel genus, Acidicapsa gen. nov., and two novel species. Acidicapsa borealis gen. nov., sp. nov. is the type species for the new genus with strain KA1(T) (=DSM 23886(T)=LMG 25897(T)=VKM B-2678(T)) as the type strain. The name Acidicapsa ligni sp. nov. is proposed for

  9. Staphylococcus aureus resistentes à meticilina: disseminação emergente na comunidade Methicillin-resistant Staphylococcus aureus: emerging community dissemination

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    Luciane Cristina Gelatti

    2009-10-01

    Full Text Available Staphylococcus aureus é uma bactéria responsável por uma ampla variedade de enfermidades infecciosas. A grande preocupação está relacionada, principalmente, com os isolados resistentes à meticilina (MRSA, que, tradicionalmente, estavam limitados aos hospitais. Nos últimos anos, infecções causadas por MRSA associadas ou adquiridas na comunidade (CA-MRSA têm sido relatadas com frequência crescente em todo o mundo. Algumas características fenotípicas e genéticas são distintas entre a forma de infecção hospitalar e a comunitária. Atualmente, verifica-se um perfil de sensibilidade reduzido para diferentes antimicrobianos; sendo assim faz-se necessário um alerta aos profissionais da saúde, particularmente aos dermatologistas, para a importância da distinção entre as formas de infecções, evitando uma terapia empírica incorreta e sem sucesso.Staphylococcus aureus is responsible for a broad variety of infectious diseases. The main concern is about methicillin-resistant isolates (MRSA, which are usually limited to hospitals. In recent years, community associated or acquired MRSA infections (CA-MRSA have been frequently reported and emerged in the world. Some phenotypic and genotypic characteristics are distinct between hospital and community infection. Currently, there is reduced sensibility profile to different antimicrobials, reason why it is necessary to issue an alert to healthcare professionals, dermatologists in particular, about the importance of knowing the differences between the infections, preventing wrong and unsuccessful empirical therapy.

  10. VARIABLES QUE INTERVIENEN EN LA PERSONALIDAD RESISTENTE Y LAS ESTRATEGIAS DE AFRONTAMIENTO EN ADULTOS MAYORES/ VARIABLES INTERVENING IN RESISTANT PERSONALITY AND MANAGEMENT STRATEGIES IN AGED PEOPLE

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    Zoila Edith Hernández Zamora*

    2009-10-01

    Full Text Available Resumen:El objetivo de esta investigación fue determinar el nivel de Personalidad Resistente (PR, su relación con el nivel deestrategias de afrontamiento así como con otras variables psicológicas y sociodemográficas de una muestra de 102 adultosmayores que asisten a una estancia diurna especial para este grupo etario. Los resultados muestran que la mayoría de losparticipantes tienen un nivel alto de PR y ninguna resultó con un nivel bajo en este constructo. Las variables asociadassignificativamente con una PR alta son: sexo, independencia, escolaridad, autopercepción de salud y repercusión en elestado de ánimo de sus enfermedades. En cuanto al nivel de estrategias de afrontamiento la mayoría se ubicó en el nivelmedio, no existiendo correlaciones en este aspecto con otras variables de estudio. Se recomienda hacer otras investigacionescon poblaciones de este mismo grupo etario aunque en diferentes hábitats, así como con otros grupos etarios para compararresultados.Abstract:The purpose of this research was to determine the level of Resistant Personality (RP, its relationship with the level ofmanagement strategies, as well as with other psychological and sociodemographic variables of a sample of 102 agedpersons who attend a diurnal home special for this kind of people. The results show that most of the participants have a highlevel of RP, and no one resulted with a low level in this constructo. The variables significantly associated with a high RP are:sex, independence, education, self perception of health, and repercussion on their mood of their illnesses. According to thelevel of management strategies, most of them were placed at middle level, without exixting correlations in this aspect withother variables of study. Werecommend to carry out further research with populations of this same kind of group, althoughin different habitas, as well as with other groups to compare the results.

  11. Análisis genómico del resistoma de la cepa de Acinetobacter baumannii ABIBUN 107m multi-resistente y persistente en hospitales colombianos

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    Maria Teresa Reguero

    2014-07-01

    Full Text Available Título en español: Análisis genómico del resistoma de la cepa  de  Acinetobacter baumannii  ABIBUN 107m multi-resistente  y persistente  en hospitales colombianos Título en ingles: Genomic analysis of the resistoma of the strain of Acinetobacter baumannii ABIBUN 107m multi-resistant and persistent in Colombian hospitals Título corto: Análisis genómico del resistoma de la cepa  de  Acinetobacter baumannii  Resumen: Acinetobacter baumannii es una bacteria, causante de infecciones asociadas a la atención en salud como neumonía, septicemia, meningitis e infecciones urinarias entre otras. Se caracteriza por su capacidad para desarrollar y acumular rápidamente una gran variedad de mecanismos de resistencia a antibióticos. En esta investigación se realizó el análisis genómico de una cepa de A. baumannii ABIBUN 107m que forma parte de un clon persistente en hospitales colombianos, resistente a los antibióticos carbapenémicos (imipenem y meropenem,  antibióticos de elección en el tratamiento  infecciones causadas por este microorganismo. El genoma de esta bacteria fue secuenciado utilizando técnicas de alto rendimiento, ensamblado y anotado, obteniéndose un genoma constituido por  3954000 pb con 56 contigs;  consta de 4256 genes con un tamaño promedio de 912 pb;  3796 CDS  de los cuales por anotación 2884  se asignaron a COG; 57 tRNA y un porcentaje de GC de 38,74%. A. baumannii ABIBUN 107m es resistente a b-lactámicos, aminoglicósidos, quinolonas, tetraciclina, sulfonamida y colistina. En su genoma se localizaron genes asociados con el perfil de resistencia ya que presenta serin b-lactamasas (blaADC-38, blaOXA-64, blaOXA-23, blaampC-like,  blaamp(H-like, metalo b-lactamasa_B;  proteínas de unión a  penicilina de elevada masa molecular, secuencias de inserción tipo ISAba1; mutaciones en los genes de DNA girasa  y topoisomerasa IV subunidad A (gyrA y parC; enzimas modificadoras de aminoglicósidos (aph

  12. [Optimization of a cake formulation with functional characteristics using resistant starch, Sphagnum magellanicum moss and deffated hazel nut flour (Gevuina avellana, Mol)].

    Science.gov (United States)

    Villarroel, Mario; Reyes, Carla; Hazbun, Julia; Karmelic, Julia

    2007-03-01

    Resistant starch (RS) Hi Maize 260, Sphagnum magellanicum Moss (SM) both natural resources rich in total dietary fiber, and defatted hazel nut flour (DHN) as protein resource were used in the development of a pastry product (queque) with functional characteristics. Taguchi methodology was utilized in the optimization process using the orthogonal array L934 with four control factors: RS, SM. DHN and Master Gluten 4000 (MG), 3 factor levels and 9 experimental trials. The best result of Sensory Quality (SQ) and signal to noise ratio (S/N) was obtained combining the minor levels of the independent variables. Main effect (average effects of factor) analysis and anova analysis showed that SM and DHN were the control factors with a significant influence (pcakes showed very good results when they were submitted to hedonic test with 100% of favorable consumer's opinions.

  13. Fluoroquinolone susceptibilities to methicillin-resistant and susceptible coagulase-negative Staphylococcus isolated from eye infection Suscetibilidade dos Staphylococcus coagulase negativo meticilina-resistentes e suscetíveis isolados em infecções oculares

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    Adália Dias Dourado Oliveira

    2007-03-01

    Full Text Available PURPOSE: To evaluate the fluoroquinolone susceptibilities of ocular isolate coagulase-negative staphylococci (CoNS, identified at the Microbiology Laboratory - UNIFESP. DESIGN: Experimental laboratory investigation. METHODS: The minimum inhibitory concentrations (MICs of 21 strains of methicillin-resistant coagulase-negative staphylococci (MRCoNS and 22 methicillin-sensitive coagulase-negative staphylococci (MSCoNS to ciprofloxacin, ofloxacin, gatifloxacin and moxifloxacin were determined, using the E-test method standardized by the Clinical and Laboratory Standards Institute (CLSI/NCCLS. RESULTS: The MIC90s (µg/ml for the second generation of tested fluoroquinolones were higher than the fourth generation, especially for the methicillin-resistant coagulase-negative staphylococci group. CONCLUSION: Our results indicate that methicillin-sensitive coagulase-negative staphylococci are more susceptible to quinolones than are methicillin-resistant coagulase-negative staphylococci and that fourth generation fluoroquinolones appear to be more potent, affecting even coagulase-negative staphylococcal strains resistant to second generation fluoroquinolones.OBJETIVOS: Avaliar a suscetibilidade a fluorquinolonas dos Staphylococcus coagulase-negativo (SCoN identificados no Laboratório de Microbiologia Ocular da Unifesp. MÉTODOS: Foi determinada a concentração inibitória mínima de 21 cepas de SCoN meticilina-resistentes e 22 meticilina-sensíveis para ciprofloxacina, ofloxacina, gatifloxacina e moxifloxacina, utilizando o E-test estandartizado pelo CLSI/NCCLS. RESULTADOS: Os MIC90 (µg/ml de 43 SCoN isolados para fluorquinolonas de segunda geração foram maiores do que os de quarta geração, principalmente para o grupo dos meticilina-resistentes. CONCLUSÃO: Nossos resultados indicam que Staphylococcus coagulase-negativo meticilina-sensíveis são mais suscetíveis às quinolonas do que os Staphylococcus coagulase-negativo meticilina-resistentes

  14. Desempenho de populações híbridas F2 de arroz-vermelho (Oryza sativa) com arroz transgênico (O. sativa) resistente ao herbicida amonio-glufosinate

    OpenAIRE

    Noldin, J.A.; Yokoyama, S.; Stuker, H.; Rampelotti, F.T.; Gonçalves, M.I.F.; Eberhardt, D.S.; Abreu, A.; Antunes, P.; Vieira, J.

    2004-01-01

    O arroz-vermelho e o arroz-preto constituem-se nas principais plantas daninhas infestantes da cultura de arroz irrigado, devido à dificuldade de controle seletivo desta espécie em lavouras comerciais. A utilização de cultivares geneticamente modificados resistentes a herbicidas não-seletivos constitui uma alternativa de controle do arroz-vermelho e arroz-preto em arroz irrigado. O objetivo deste trabalho foi avaliar o comportamento de populações híbridas F2 originárias do cruzamento entre o a...

  15. Ocorrência de raças de Bremia lactucae no Estado de São Paulo no triênio 2008 - 2010, e desenvolvimento de linhagens de alface crespa resistentes

    OpenAIRE

    Castoldi, Renata [UNESP

    2011-01-01

    A alface é a hortaliça folhosa de maior consumo no Brasil, no entanto a dificuldade em produzi-la vem aumentando, principalmente pela infestação das áreas de produção por Bremia lactucae, sendo necessário o monitoramento anual para utilização ou desenvolvimento de cultivares resistentes. Diante do exposto, os objetivos do presente trabalho foram: identificação de raças de B. lactucae no Estado de São Paulo, durante os anos de 2008, 2009 e 2010 e obtenção de linhagens de alface crespa resisten...

  16. Caracterización del gen mecA de Staphylococcus aureus resistentes a meticilina aislados de tres grupos poblacionales de la ciudad de Medellín

    Directory of Open Access Journals (Sweden)

    Marcela Sanchez

    Full Text Available Introducción: Staphylococcus aureus resistente a la meticilina (SARM es responsable de infecciones intrahospitalarias, las que constituyen una importante causa de morbilidad y mortalidad en nuestro medio, por lo cual la rápida identificación y tipificación molecular de la resistencia como el complejo SSCmec es esencial para entender la epidemiología de la infección. Objetivo: Caracterizar fenotípicamente la resistencia a meticilina y genotípicamente el casete cromosomal SSCmec en cepas de S. aureus aislados de individuos de la ciudad de Medellín mediante PCR múltiple. Materiales y métodos: A 41 aislamientos (hospitalarios y de la comunidad de S. aureus se les estableció la resistencia a cefoxitin mediante la técnica de Kirby-Bauer y la concentración inhibitoria mínima para oxacilina. Mediante PCR convencional se les confirmó la presencia del gen mecA. Para la tipificación del complejo SSCmec se utilizó PCR múltiple para amplificar 6 loci diferentes de este gen. Resultados: A todos los aislamientos se les confirmó resistencia a meticilina y la presencia del gen mecA, de los cuales 17 fueron clasificados como SSC mec I, 1 como SSC mec II, 21 como SSC mecIV; dos aislamientos no fue posible clasificarlos. Conclusiones: Con el uso de esta técnica clasificamos el 95% de los aislamientos del estudio, encontrando una mayor prevalencia de los SSCmec I y IV. La implementación de esta técnica permite una fácil caracterización de los aislamientos SARM y un apropiado manejo de la información de los integrantes de los comités de infecciones hospitalarios, lo cual podría impactar positivamente en el tratamiento a los pacientes y el control de enfermedades infecciosas intrahospitalarias.

  17. Incidência de infecções por enterobactérias resistentes a carbapenêmicos em pacientes previamente colonizados

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    Paula Lüttjohann Rodrigues

    2015-09-01

    Full Text Available Introdução: Nos últimos anos, a incidência mundial de enterobactérias resistentes a carbapenêmicos (ERC tem aumentado. A disseminação de ERC é preocupante considerando as limitações terapêuticas e a alta mortalidade de infecções causadas por essas bactérias. O objetivo deste estudo foi determinar a incidência de infecções por ERC em pacientes previamente colonizados. Métodos: Estudo de coorte, retrospectivo, realizado em hospital universitário de Porto Alegre, no período de janeiro a dezembro de 2014. Foram incluídos todos os pacientes com coleta de swab retal para pesquisa de ERC. Foram considerados infectados pacientes com isolado de ERC em amostra clínica que apresentaram swab retal prévio positivo para a mesma espécie. A mortalidade bruta foi analisada em 30 dias após o isolamento de ERC. Resultados: Foram coletados 2.733 swabs retais, sendo 78 (2,85% destes positivos para ERC (pacientes colonizados. Um total de 33% (26/78 dos pacientes colonizados também apresentaram ERC em amostra clínica. O tempo médio entre o isolamento de ERC em swab (colonização e em material clínico (infecção foi de 14,9 dias (± 13,6. A maior parte das amostras clínicas positivas para ERC foi em urina (46,1%; 12/26. A mortalidade foi de 61% (16/26 nos pacientes colonizados e com infecção versus 46% (24/52 nos pacientes colonizados que não desenvolveram infecção. Conclusão: Nossos dados demonstram que 1/3 de pacientes colonizados desenvolveram infecção por ERC. Foi possível observar uma mortalidade maior em pacientes infectados em relação a pacientes apenas colonizados por ERC.

  18. AMIDO DISPONÍVEL E RESISTENTE EM ALIMENTOS: ADAPTAÇÃO DO MÉTODO DA AOAC 996.11

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    M. WALTER

    2008-09-01

    Full Text Available

    Muitos métodos para a quantificação do amido disponível (AD e resistente (AR foram desenvolvidos nos últimos anos. Entretanto, a utilização de diferentes enzimas, assim como de diferentes quantidades de amostra, leva a variações no teor destas frações dificultando a comparação dos resultados obtidos. Desta forma, o objetivo do presente trabalho foi avaliar o efeito da utilização de protease, do aumento da quantidade de amostra (de 100mg para 300mg e da substituição do tampão MOPS pH 7,0 por tampão fosfato pH 6,8 na determinação de AD e AR pela técnica da AOAC 996.11. Para tanto, utilizou-se como amostra amido de milho, arroz branco polido, banana verde e flocos de milho. A utilização de protease no processo de digestão, bem como o aumento na quantidade de amostra, influenciaram significativamente o teor de AD e AR para a maioria dos materiais analisados. Já, a substituição por tampão fosfato não resultou em variação significativa para os teores de AD e AR. Portanto, o protocolo com as três modificações, por apresentar melhor simulação das condições hidrolíticas no trato gastrintestinal, menores coeficientes de variação e custo reduzido pela substituição do tampão, seria o mais adequado à quantificação destas frações do amido.

  19. Comparación resistente de cuatro métodos de refuerzo de pilares de hormigón armado

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    Ramírez Ortiz, J. L.

    1977-05-01

    Full Text Available This report, which is a continuation of another appearing in Construction Report no. 272 (July 1975, studies the stress performance of reinforced concrete columns in insulated floors, usíng four different procedures: — Two of the reinforcement methods presently used are an improvement over those previously used in the other report. They consist of increasing the croas section with concrete which penetrates in grooves made in the original concrete or by backing the steel angles to the columns edges with angular members against the forging, but obtaining the best possible fitting between the concrete and steel by using resins. — The other two methods are new in our experiments. They consist in creating an outer liner of concrete with binder framework and in the metal solution by going through the column with the double T which transfers part of the load directy to the two strongest clips.Este trabajo, que es continuación de otro aparecido en INFORMES DE LA CONSTRUCCIÓN, número 272 (julio 1975, estudia el comportamiento resistente de pilares de hormigón armado reforzados en pisos aislados, por otros cuatro procedimientos diferentes: — Dos de los métodos de refuerzo actualmente utilizados son una mejora de los empleados en el trabajo anterior. Consisten en el recrecido de la sección transversal con hormigón que penetra en cajeras practicadas en el hormigón original o adosado de angulares de acero a las aristas del pilar con capitel de angulares contra el forjado, pero procurando el mejor ajuste entre hormigón y acero mediante resinas. — Los otros dos métodos son nuevos en nuestra experimentación. Consisten en crear una camisa exterior de hormigón con armadura de zuncho y en la solución metálica en atravesar el pilar con una doble T que transfiera parte de la carga directamente a dos presillas más robustas y, por tanto, dar menos importancia a la transmisión de esfuerzos por ei capitel que siempre es algo flexible.

  20. Enfermedad invasora por Staphylococcus aureus meticilino resistente adquirida en la comunidad Community-acquired methicillin-resistant Staphylococcus aureus disseminated disease

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    Clarisa Brezzo

    2006-10-01

    Full Text Available Se presenta un caso de enfermedad invasora por Staphylococcus aureus meticilino resistente (SAMR adquirido en la comunidad (SAMR-c. Paciente varón de 21 años, previamente sano, que consultó por nódulos subcutáneos compatibles con gomas. La ultrasonografía reveló múltiples abscesos subcutáneos e imágenes consistentes con piomiositis, además de derrame pleural y pericárdico. En el cultivo del material purulento obtenido por punción-aspiración con aguja fina de las lesiones se aisló S. aureus. El antibiograma por difusión mostró resistencia a cefalotina, eritromicina y clindamicina, y sensibilidad a trimetroprima-sulfametoxazol, ciprofloxacina y rifampicina. La meticilino resistencia se confirmó por aglutinación con partículas de látex sensibilizadas con anticuerpos monoclonales dirigidos contra la proteína ligadora de penicilina 2A. El paciente fue tratado con ciprofloxacina y rifampicina durante cuatro semanas, con evolución favorable. La frecuencia de infecciones por SAMR-c está en aumento, observándose en personas sin factores de riesgo aparentes. Esto llevaría a fracaso en el tratamiento empírico para infecciones de la comunidad en los que se presume etiología estafilocócica.A 21 year old man, previously healthy, presented with subcutaneous nodes consistent with gummas. Ultrasonography disclosed multiple subcutaneous abscesses and images suitable with piomiositis, pleural and pericardium effusion. A puncture-aspirate with fine-needle was performed and produced purulent material, with isolate of Staphylococcus aureus. Antimicrobial susceptibility testing by disk diffusion showed resistant to cefalotin, erythromycin and clindamycin, and susceptibility to trimethoprim-sulfamethoxazole, ciprofloxacin and rifampicin. Methicilin-resistance was confirmed by Staphyslide agglutination testing (Biomérieux. The patient was treated with ciprofloxacin and rifampicin during four weeks, with a good clinical response. The

  1. Herbicidas alternativos para controle de biótipos de Conyza bonariensis e C. canadensis resistentes ao glyphosate Alternative herbicides to control glyphosate-resistant biotypes of Conyza bonariensis and C. canadensis

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    M.S. Moreira

    2010-01-01

    Full Text Available Após sucessivos anos, aplicações do herbicida glyphosate em pomares de citros no Estado de São Paulo selecionaram biótipos resistentes de Conyza bonariensis e C. canadensis. Na ocorrência de plantas daninhas resistentes em uma área agrícola, tornam-se necessárias mudanças nas práticas de manejo para obtenção de adequado controle das populações resistentes, bem como para a redução da pressão de seleção sobre outras espécies. Assim, este trabalho foi realizado com o objetivo de identificar herbicidas alternativos para controle de biótipos de Conyza spp. resistentes ao herbicida glyphosate, com aplicações em diferentes estádios fenológicos da planta daninha. Três experimentos foram conduzidos em campo, em pomares de citros em formação, sobre plantas de buva em estádio fenológico de dez folhas e no pré-florescimento. Para plantas no estádio de dez folhas, controle satisfatório foi obtido com aplicações de glyphosate + bromacil + diuron (1.440 + 1.200 + 1.200 g ha-1, glyphosate + atrazina (1.440 + 1.500 g ha-1 e glyphosate + diuron (1.440 + 1.500 g ha-1. Quando em estádio de pré-florescimento de Conyza spp., a aplicação do herbicida amônio-glufosinato, na dose de 400 g ha-1, isolado ou associado a MSMA, bromacil+diuron, metsulfuron, carfentrazone e paraquat, foi a alternativa viável para controle dos biótipos resistentes ao glyphosate.After successive years, glyphosate applications on São Paulo-Brazil citrus orchards selected resistant biotypes of Conyza bonariensis and C. canadensis. The occurrence of herbicide-resistant weed biotypes at some agricultural area makes it necessary to change the management practices to reach effective control of the selected resistant populations, as well as to reduce selection pressure on the other species. Thus, this work aimed to identify the alternative herbicides to control glyphosate-resistant biotypes of Conyza spp., with applications at different weed phenological

  2. Knockdown resistance in pyrethroid-resistant horn fly (Diptera: Muscidae populations in Brazil Resistência Knockdown em populações de mosca-dos-chifres do Brasil resistentes aos piretróides

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    Gustavo A. Sabatini

    2009-09-01

    Full Text Available To investigate the kdr (knockdown resistance resistance-associated gene mutation and determine its frequency in pyrethroid-resistant horn fly (Haematobia irritans populations, a total of 1,804 horn flies of 37 different populations from all Brazilian regions (North, Northeast, Central-West, Southeast, and South were molecular screened through polymerase chain reaction (PCR. The kdr gene was not detected in 87.08% of the flies. However, the gene was amplified in 12.92% of the flies, of which 11.70% were resistant heterozygous and 1.22% were resistant homozygous. Deviation from Hardy-Weinberg equilibrium (HWE was found only in 1 ranch with an excess of heterozygous. When populations were grouped by region, three metapopulations showed significant deviations of HWE (Central-West population, South population and Southeast population. This indicates that populations are isolated one from another and kdr occurrence seems to be an independent effect probably reflecting the insecticide strategy used by each ranch. Although resistance to pyrethroids is disseminated throughout Brazil, only 48% of resistant populations had kdr flies, and the frequency of kdr individuals in each of these resistant populations was quite low. But this study shows that, with the apparent exception of the Northeast region, the kdr mechanism associated with pyrethroid resistance occurs all over Brazil.Com o objetivo de verificar a ocorrência e determinar a frequência da mutação kdr (knock down resistance em populações de Haematobia irritans (mosca-dos-chifres resistentes aos piretróides, foram analisados 1.804 indivíduos de 37 populações de todas as Regiões do Brasil. Com exceção da Região Nordeste, o kdr (knock down resistance gene foi encontrado em populações de todas as regiões. A mutação não foi detectada em 87,08% dos indivíduos. Entretanto, o gene foi amplificado de 12,92% das moscas, das quais 11,70% se mostraram heterozigotas resistentes e 1

  3. Antibacterial activity of plant extracts and phytochemicals on antibiotic-resistant bacteria Atividade de extratos vegetais e fitofármacos sobre bactérias resistentes a antibióticos

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    Gislene G. F. Nascimento

    2000-10-01

    Full Text Available The antimicrobial activity of plant extracts and phytochemicals was evaluated with antibiotic susceptible and resistant microorganisms. In addition, the possible synergistic effects when associated with antibiotics were studied. Extracts from the following plants were utilized: Achillea millifolium (yarrow, Caryophyllus aromaticus (clove, Melissa offficinalis (lemon-balm, Ocimun basilucum (basil, Psidium guajava (guava, Punica granatum (pomegranate, Rosmarinus officinalis (rosemary, Salvia officinalis (sage, Syzygyum joabolanum (jambolan and Thymus vulgaris (thyme. The phytochemicals benzoic acid, cinnamic acid, eugenol and farnesol were also utilized. The highest antimicrobial potentials were observed for the extracts of Caryophyllus aromaticus and Syzygyum joabolanum, which inhibited 64.2 and 57.1% of the tested microorganisms, respectively, with higher activity against antibiotic-resistant bacteria (83.3%. Sage and yarrow extracts did not present any antimicrobial activity. Association of antibiotics and plant extracts showed synergistic antibacterial activity against antibiotic-resistant bacteria. The results obtained with Pseudomonas aeruginosa was particularly interesting, since it was inhibited by clove, jambolan, pomegranate and thyme extracts. This inhibition was observed with the individual extracts and when they were used in lower concentrations with ineffective antibiotics.Foi avaliada a atividade antimicrobiana de extratos vegetais e fitofármacos frente a microrganismos sensíveis e resistentes a antibióticos, bem como observado o possível efeito sinérgico da associação entre antibióticos e extratos vegetais. Foram utilizados os extratos de plantas cujo nomes populares são: tomilho, alecrim, cravo-da-Índia, jambolão, erva cidreira, romã, goiaba, sálvia, manjericão e mil-folhas, e ainda os fitofármacos, ácido benzóico, ácido cinâmico, eugenol e farnesol. Na avaliação da atividade antimicrobiana através do m

  4. Staphylococcus aureus resistente a vancomicina.

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    Carlos Andrés Rodríguez

    2005-12-01

    Full Text Available Objetivo. Revisar la evolución y mecanismos moleculares de la resistencia de Staphylococcus aureus a vancomicina. Fuente de los datos. Se consultó la base de datos MEDLINE y se seleccionaron artículos tipo reportes de caso, estudios bioquímicos, de microscopía electrónica y biología molecular pertinentes. Síntesis. Después de casi 40 años de eficacia ininterrumpida de la vancomicina, en 1997 se reportaron los primeros casos de fracaso terapéutico debido a cepas de Staphylococcus aureus con resistencia intermedia, denominadas VISA (concentración inhibitoria mínima, CIM, 8 a 16 ?g/ml, así como a cepas con resistencia heterogénea hVISA (CIM global = 4 ?g/ml, pero con subpoblaciones VISA, en las cuales la resistencia está mediada por engrosamiento de la pared celular y disminución de su entrecruzamiento, lo que afecta la llegada del antibiótico al blanco principal, los monómeros del peptidoglicano en la membrana plasmática. En 2002 se aisló la primera de las 3 cepas reportadas hasta la fecha con resistencia total al antibiótico, denominadas VRSA (CIM>32 ?g/ml, en las que se encontró el transposón Tn1546 proveniente de Enterococcus spp, responsable del reemplazo de la terminación D-Ala-D-Ala por D-Ala-Dlactato en los precursores de la pared celular con pérdida de la afinidad por el glicopéptido. Conclusiones. La resistencia a vancomicina es una realidad en S. aureus, mediada en el caso de VISA por alteraciones en la pared celular que atrapan el antibiótico antes de llegar al sitio de acción, y en el caso de VRSA, por transferencia desde Enterococcus spp. de genes que llevan a la modificación del blanco molecular.

  5. Towards better understanding of the response of Sphagnum peatland to increased temperature and reduced precipitation in Central Europe

    Science.gov (United States)

    Juszczak, Radoslaw; Basińska, Anna; Chojnicki, Bogdan; Gąbka, Maciej; Hoffmann, Mathias; Józefczyk, Damian; Lamentowicz, Mariusz; Leśny, Jacek; Łuców, Dominika; Moni, Christophe; Reczuga, Monika; Samson, Mateusz; Silvennoinen, Hanna; Stróżecki, Marcin; Urbaniak, Marek; Zielińska, Małgorzata; Olejnik, Janusz

    2017-04-01

    With respect to climate change peatlands are highly vulnerable ecosystems. Especially a potential drying in future might result in a major carbon source and release to the atmosphere. We carried out a field climate manipulation experiment at Rzecin peatland in western Poland to assess how increased temperature and reduced precipitation may impact carbon balance, vegetation, microbes and water chemistry of the Sphagnum peatland. Here, we present results of measurements conducted in two contrasting years (417 mm and 678 mm of precipitation in very dry 2015 and wet 2016, respectively). The experimental design consists of four treatments, each one replicated three times (control, CO; simulated warming, W; prolonged drought, D and warming & drought, W+D). Increased temperatures (T) during the year were achieved by infrared heaters (400W × 4 per site, approx. 60 Wṡm-2 addition of LW radiation). Precipitation was reduced using an automatic curtain, covering the site during nighttime hours of the growth seasons. The manipulation experiment was successful during both years, increasing the air (30 cm height) and soil temperature (5 cm depth, sites W and D) by up to 0.2 oC and 1.0 oC, respectively. Precipitation was reduced to 37 % during both years. At W+D site the peat temperature was nearly two times higher than on W site indicating the impact of drought on T increase. To study the C exchange we developed an automatic mobile platform for measuring CO2/CH4/H2O fluxes (LGR) as well as 13CO2 and 13CH4 fluxes (PICARRO CRDS G2201-i). Measurements were performed, using dynamic ecosystem chambers (for NEE and Reco) and combined with simultaneous measurements of surface spectral properties. Flux calculation and gap filling was done according to Hoffmann et al. 2015. Methane emissions were significantly higher on manipulated plots than on CO (25 gCṡm-2yr-1) during both years, but only in the very dry 2015, CH4 fluxes were the highest on W+D site (33 gC gCṡm-2yr-1). Besides

  6. Plantio irrigado de bananeiras resistentes à Sigatoka-negra consorciado com culturas anuais Irrigated banana resistant to black Sigatoka, with annual intercrops

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    Ildeu de Souza

    2010-03-01

    Full Text Available Com o objetivo de avaliar o plantio irrigado de bananeiras resistentes à Sigatoka-negra consorciado com cultura anuais, na região norte de Minas Gerais, um experimento foi instalado na Fazenda Experimental do Departamento de Ciências Agrárias da Universidade Estadual de Montes Claros, Câmpus de Janaúba-MG. O experimento foi conduzido no período de abril de 2006 a julho de 2007, delineado em blocos casualizados, segundo um esquema de parcelas subdivididas 3 x 5, tendo na parcela as três variedades de bananeiras: Pacovan Ken, Caipira e Thap Maeo, e na subparcela quatro culturas intercalares: Feijão-Pérola, Quiabo-Dardo, Melancia-Crimson-Sweet e Feijão-Caupi, e a testemunha (sem cultura intercalar, com três repetições. Ao todo, foram 756 bananeiras, em 45 parcelas, com 6 plantas úteis cada, constituindo a cultura principal. As culturas intercalares ocuparam as entrelinhas da bananeira, tanto aquelas com as linhas de irrigação como sem linha de irrigação. O plantio da bananeira e das culturas intercalares foi feito no mesmo período, utilizando-se do espaçamento de 3,0 m entre as linhas e 2,0 m entre as covas de bananeira, com microaspersores espaçados de 6 m. Avaliaram-se as características vegetativas e reprodutivas das variedades de bananeiras, no primeiro ciclo. Não foi observado efeito significativo dos cultivos intercalares sobre as variedades de bananeiras, com exceção do número de dias do plantio ao florescimento e do número de dias do plantio à colheita das variedades de bananeiras. O uso do feijão-caupi promoveu atraso no ciclo de produção das três variedades de bananeiras Pacovan Ken, Caipira e Thap Maeo.To assess the irrigated cultivation of banana resistant to black Sigatoka, intercropped with annual crops in the northern region of Minas Gerais, a trial was conducted on an experimental farm of the Universidade Estadual de Montes Claros, in Janaúba-MG. The experiment was carried out from April 2006 to

  7. Leptina e aldosterona na atividade simpática na hipertensão resistente, com ou sem Diabetes Tipo 2

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    Leandro Boer-Martins

    2012-07-01

    Full Text Available FUNDAMENTO: A descoberta da leptina como um estimulador da atividade simpática trouxe uma nova perspectiva para os mecanismos fisiopatológicos da obesidade-hipertensão. OBJETIVO: Avaliamos a relação entre a atividade simpática aumentada e as concentrações plasmáticas de leptina e aldosterona em Hipertensos Resistentes (HR, comparando os grupos com e sem Diabetes Tipo 2 (DT2. MÉTODOS: Vinte e cinco pacientes HR foram avaliados por eletrocardiografia ambulatorial para análise da Variabilidade da Frequência Cardíaca (VFC nos domínios do tempo e frequência, os quais foram estratificados em dois períodos: 24 horas e período Diurno (D, compreendendo as medidas entre 14 e 18h (domínio do tempo e uma hora às 15h (domínio da frequência. RESULTADOS: O grupo DT2 (n = 10 apresentou maiores concentrações de aldosterona e leptina que o grupo não DT2 (n = 15 (26,0 ± 11,5 vs. 16,9 ± 7,0 ng/dL - p = 0,021; 81,368.7 ± 47,086.1 vs. 41,228.1 ± 24,523.1 pg/mL - p = 0,048, respectivamente. Houve correlação entre aldosterona e VFC no domínio da frequência em ambos os grupos. Não-DT2 apresentaram a aldosterona correlacionada com D baixa frequência em unidades normalizadas (BFnu (r = 0,6 [0,12 - 0,85] p = 0,018 e D alta frequência em unidades normalizadas (AFnu (r = -0,6 [-0,85 - -0,12] p = 0,018. No grupo com diabetes, a aldosterona correlacionou-se com DBFnu (r = 0,72 [0,16 - 0,93] p = 0,019 e DAFnu (r = -0,72 [-0,93 - -0,16] p = 0,019. Apesar da importância da leptina na atividade simpática aumentada na hipertensão, não houve correlação com VFC. CONCLUSÃO: A aldosterona parece estimular a atividade simpática em HR com ou sem DT2. Essa informação combinada com a eficácia clínica dos bloqueadores de receptor mineralocorticoide em HR pode reforçar a aldosterona como alvo terapêutico relevantes em HR. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0

  8. Seasonal and inter-annual variation in the chlorophyll content of three co-existing Sphagnum species exceeds the effect of solar UV reduction in a subarctic peatland.

    Science.gov (United States)

    Hyyryläinen, Anna; Rautio, Pasi; Turunen, Minna; Huttunen, Satu

    2015-01-01

    We measured chlorophyll (chl) concentration and chl a/b ratio in Sphagnum balticum, S. jensenii, and S. lindbergii, sampled after 7 and 8 years of ultraviolet-B (UVB) and temperature manipulation in an open field experiment in Finnish Lapland (68°N). We used plastic filters with different transmittance of UVB radiation to manipulate the environmental conditions. The plants were exposed to (1) attenuated UVB and increased temperature, (2) ambient UVB and increased temperature and (3) ambient conditions. Chlorophyll was extracted from the capitula of the mosses and the content and a/b ratio were measured spectrophotometrically. Seasonal variation of chlorophyll concentration in the mosses was species specific. Temperature increase to 0.5-1 °C and/or attenuation of solar UVB radiation to ca. one fifth of the ambient (on average 12 vs. 59 uW/cm(2)) had little effect on the chlorophyll concentration or its seasonal variation. In the dominant S. lindbergii, UVB attenuation under increased temperature led to a transient decrease in chlorophyll concentration. Altogether, species-specific patterns of seasonal chlorophyll variation in the studied Sphagna were more pronounced than temperature and UVB treatment effects.

  9. PCA and multidimensional visualization techniques united to aid in the bioindication of elements from transplanted Sphagnum palustre moss exposed in the Gdańsk City area.

    Science.gov (United States)

    Astel, Aleksander; Astel, Karolina; Biziuk, Marek

    2008-01-01

    During the last decades, a technique for assessing atmospheric deposition of heavy elements was developed based on the principle that samples of moss are able to accumulate elements and airborne particles from rain, melting snow and dry deposition. Despite a broad interest in bioindication there are still ongoing works aimed at the preparation of a standard procedure allowing for a comparison of research carried out in various areas. This is why the comparison of living and dry moss of the same species and growth site seems to be interesting, logical and promising. A most reliable approach seems to be the application of bioindication connected with multivariate statistics and efficient visualization techniques in the interpretation of monitoring data. The aim of this study was: (i) to present cumulative properties of transplanted Sphagnum palustre moss with differentiation into dry and living biomaterial; (ii) to determine and geographically locate types of pollution sources responsible for a structure of the monitoring data set; (iii) to visualize geographical distribution of analytes in the Gdańsk metropolitan area and to identify the high-risk areas which can be targeted for environmental hazards and public health. A six month air pollution study based on Sphagnum palustre bioindication is presented and a simplified procedure of the experiment is given. The study area was located at the mouth of the Vistula River on the Baltic Sea, in Gdańsk City (Poland). Sphagnum palustre was selected for research because of its extraordinary morphological properties and its ease in being raised. The capability of dry and living moss to accumulate elements characteristic for anthropogenic and natural sources was shown by application of Principal Component Analysis. The high-risk areas and pollution profiles are detected and visualized using surface maps based on Kriging algorithm. The original selection of elements included all those that could be reliably determined by

  10. Combining short-term manipulative experiments with long-term palaeoecological investigations at high resolution to assess the response of Sphagnum peatlands to drought, fire and warming

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    M. Lamentowicz

    2016-09-01

    Full Text Available Northern hemisphere peatlands are substantial carbon stores. However, recent climate change and human impacts (e.g., drainage and atmospheric nutrient deposition may trigger the emission of their stored carbon to the atmosphere. Biodiversity losses are also an important consequence of those changes. Therefore, there is a need to recognise these processes in space and time. Global change experiments are often conducted to improve our understanding of the potential responses of various ecosystems to global warming and drought. Most of the experiments carried out in peatlands are focused on carbon balance and nitrogen deposition. Nevertheless, it is still unclear how fast peatlands respond to temperature changes and water-table lowering in the continental climate setting. This is important because continental regions account for a significant proportion of all northern hemisphere peatlands. A combination of short-term and long-term approaches in a single research project is especially helpful because it facilitates the correct interpretation of experimental data. Here we describe the CLIMPEAT project - a manipulative field experiment in a Sphagnum-dominated peatland supported by a high-resolution multi-proxy palaeoecological study. The design of the field experiment (e.g., treatments, methodology and biogeographical setting are presented. We suggest it is beneficial to support field experiments with an investigation of past environmental changes in the studied ecosystem, as human impacts during the past 300 years have already caused substantial changes in ecosystem functioning which may condition the response in experimental studies.

  11. Modelling and mapping trace element accumulation in Sphagnum peatlands at the European scale using a geomatic model of pollutant emissions dispersion.

    Science.gov (United States)

    Diaz-de-Quijano, Maria; Joly, Daniel; Gilbert, Daniel; Toussaint, Marie-Laure; Franchi, Marielle; Fallot, Jean-Michel; Bernard, Nadine

    2016-07-01

    Trace elements (TEs) transported by atmospheric fluxes can negatively impact isolated ecosystems. Modelling based on moss-borne TE accumulation makes tracking TE deposition in remote areas without monitoring stations possible. Using a single moss species from ombrotrophic hummock peatlands reinforces estimate quality. This study used a validated geomatic model of particulate matter dispersion to identify the origin of Cd, Zn, Pb and Cu accumulated in Sphagnum capillifolium and the distance transported from their emission sources. The residential and industrial sectors of particulate matter emissions showed the highest correlations with the TEs accumulated in S. capillifolium (0.28(Zn)-0.56(Cu)) and (0.27(Zn)-0.47(Cu), respectively). Distances of dispersion varied depending on the sector of emissions and the considered TE. The greatest transportation distances for mean emissions values were found in the industrial (10.6 km when correlating with all TEs) and roads sectors (13 km when correlating with Pb). The residential sector showed the shortest distances (3.6 km when correlating with Cu, Cd, and Zn). The model presented here is a new tool for evaluating the efficacy of air pollution abatement policies in non-monitored areas and provides high-resolution (200 × 200 m) maps of TE accumulation that make it possible to survey the potential impacts of TEs on isolated ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Kinetics and thermodynamics of adsorption of azinphosmethyl from aqueous solution onto pyrolyzed (at 600 deg. C) ocean peat moss (Sphagnum sp.)

    International Nuclear Information System (INIS)

    Aroguz, A.Z.

    2006-01-01

    The removal of azinphosmethyl from aqueous solution onto pyrolyzed ocean peat moss (Sphagnum sp.), as a residue, from the Rhode Island coast (USA), has been investigated at different temperatures and initial concentrations. The ocean peat moss had been pyrolyzed at 600 deg. C in nitrogen atmosphere before the adsorption process. The kinetic data obtained from batch studies have been analyzed using pseudo-first order kinetic model. The rate constants were evaluated at different temperatures. The thermodynamic parameters (ΔG o , ΔH o , ΔS o ) for the adsorption process were calculated and the results suggest that the nature of adsorption is endothermic and the process is spontaneous and favorable. The activation energy for adsorption process was estimated, about 18.3 kJ mol -1 . According to this value the adsorption of azinphosmethyl onto pyrolyzed ocean peat moss is in the range of physical adsorption. The experimental data have been modeled using Langmuir, Freundlich and Temkin isotherms. It was found that Langmuir and Freundlich isotherms give the best correlation with the experimental data

  13. The effects of quantitative fecundity in the haploid stage on reproductive success and diploid fitness in the aquatic peat moss Sphagnum macrophyllum.

    Science.gov (United States)

    Johnson, M G; Shaw, A J

    2016-06-01

    A major question in evolutionary biology is how mating patterns affect the fitness of offspring. However, in animals and seed plants it is virtually impossible to investigate the effects of specific gamete genotypes. In bryophytes, haploid gametophytes grow via clonal propagation and produce millions of genetically identical gametes throughout a population. The main goal of this research was to test whether gamete identity has an effect on the fitness of their diploid offspring in a population of the aquatic peat moss Sphagnum macrophyllum. We observed a heavily male-biased sex ratio in gametophyte plants (ramets) and in multilocus microsatellite genotypes (genets). There was a steeper relationship between mating success (number of different haploid mates) and fecundity (number of diploid offspring) for male genets compared with female genets. At the sporophyte level, we observed a weak effect of inbreeding on offspring fitness, but no effect of brood size (number of sporophytes per maternal ramet). Instead, the identities of the haploid male and haploid female parents were significant contributors to variance in fitness of sporophyte offspring in the population. Our results suggest that intrasexual gametophyte/gamete competition may play a role in determining mating success in this population.

  14. Sphagnum palustre clone vs native Pseudoscleropodium purum: A first trial in the field to validate the future of the moss bag technique.

    Science.gov (United States)

    Capozzi, F; Adamo, P; Di Palma, A; Aboal, J R; Bargagli, R; Fernandez, J A; Lopez Mahia, P; Reski, R; Tretiach, M; Spagnuolo, V; Giordano, S

    2017-06-01

    Although a large body of literature exists on the use of transplanted mosses for biomonitoring of air pollution, no article has addressed so far the use and the accumulation performance of a cloned moss for this purpose. In this work, a direct comparison of metal accumulation between bags filled with a Sphagnum palustre L. clone or with native Pseudoscleropodium purum Hedw., one of the most used moss species in biomonitoring surveys, was investigated. The test was performed in sites with different atmospheric contamination levels selected in urban, industrial, agricultural and background areas of Italy and Spain. Among the eighteen elements investigated, S. palustre was significantly enriched in 10 elements (Al, Ba, Cr, Cu, Fe, Hg, Pb, Sr, V and Zn), while P. purum was enriched only in 6 elements (Al, Ba, Cu, Hg, Pb and Sr), and had a consistently lower uptake capacity than S. palustre. The clone proved to be more sensitive in terms of metal uptake and showed a better performance as a bioaccumulator, providing a higher accumulation signal and allowing a finer distinction among the different land uses and levels of pollution. The excellent uptake performance of the S. palustre clone compared to the native P. purum and its low and stable baseline elemental content, evidenced in this work, are key features for the improvement of the moss bag approach and its large scale application. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Fire activity and hydrological dynamics in the past 5700 years reconstructed from Sphagnum peatlands along the oceanic-continental climatic gradient in northern Poland

    Science.gov (United States)

    Marcisz, Katarzyna; Gałka, Mariusz; Pietrala, Patryk; Miotk-Szpiganowicz, Grażyna; Obremska, Milena; Tobolski, Kazimierz; Lamentowicz, Mariusz

    2017-12-01

    Fire is a critical component of many ecosystems and, as predicted by various climate models, fire activity may increase significantly in the following years due to climate change. Therefore, knowledge about the past fire activity of various ecosystems is highly important for future nature conservation purposes. We present results of high-resolution investigation of fire activity and hydrological changes in northern Poland. We analyzed microscopic charcoal from three Sphagnum-dominated peatlands located on the south of Baltic, on the oceanic-continental (west-east) climatic gradient, and reconstructed the history of fire in the last 5700 years. We hypothesize that air circulation patterns are highly important for local fire activity, and that fire activity is more intensive in peatlands influenced by continental air masses. We have found out that forest fires have been occurring regularly since the past millennia and were linked to climatic conditions. We show that fire activity (related to climate and fuel availability) was significantly higher in sites dominated by continental climate (northeastern Poland) than in the site located under oceanic conditions (northwestern Poland)-microscopic charcoal influx was 13.3 times higher in the eastern study site of the gradient, compared to the western study site. Recorded fire activity patterns were different between the sites in a long timescale. Moreover, most of the recorded charcoal peaks occurred during high water tables. Rising human pressure has caused droughts and water table instability, and substantial increase in fire activity in the last 400 years.

  16. Rates and Controls of N2 Fixation in Sphagnum spp. along the Hydrological Gradient - Beaver Pond to Bog Transition at Mer Bleue, Ontario, Canada

    Science.gov (United States)

    Zivkovic, T.; Moore, T. R.

    2014-12-01

    Many northern bogs with low atmospheric N inputs acquire N only via N2-fixation. Little is known about rates and controls on N2-fixation in bogs. The aim of this study was to: 1) test the important ecological drivers for N2-fixation, 2) investigate seasonal and temporal patterns of N2 fixation, and 3) to estimate current N2-fixation rates at Mer Bleue bog. We used acetylene reduction assay (ARA) to measure N2-fixation from June-October 2013 and 2014 (currently ongoing field season) along a hydrological gradient (beaver pond, hollows and hummocks). The highest ARA rates in 2013 growing season occurred in the pond in floating Sphagnum cuspidatum mats (50.3 ± 12.9 μmol m-2 d-1 Mean ± Std Err) which were up to 2.5 times latger than the rates found in the hummock with the lowest water table depth throughout the season. Two rain events during the summer 2013 increased ARA rates in all plots by 1 to 4 times, suggesting that moisture availability may play a crucial role on N2 fixation potential in the field. We are currently investigating the role of moisture, temperature, PAR and nutrient content (N, phosphorous and metals) on ARA along the gradient. In addition, we are using 15N2 enrichment method to estimate N2 fixation rates and compare them to ARA method at Mer Bleue bog.

  17. Crescimento diferencial de biótipos de Conyza SPP. resistente e suscetível ao herbicida glifosato Differential growth of glyphosate-resistant and susceptible biotypes of Conyza SPP

    Directory of Open Access Journals (Sweden)

    Murilo Sala Moreira

    2010-01-01

    Full Text Available Este trabalho foi realizado com o objetivo de comparar, em condição controlada e não-competitiva, o crescimento de biótipos de Conyza canadensis e C. bonariensis resistente e suscetível ao herbicida glifosato, a fim de quantificar os efeitos da pressão de seleção para resistência nos biótipos. Dois experimentos foram desenvolvidos com tratamentos organizados em esquema fatorial 9 x 2, com nove avaliações periódicas de crescimento e dois biótipos de cada espécie. As variáveis avaliadas por planta foram: área foliar; massa seca da parte aérea, das raízes e total, obtendo-se, a partir desta última, a taxa de crescimento absoluto. O biótipo de C. canadensis resistente ao glifosato possui crescimento mais lento, menor acúmulo de área foliar e de massa seca que o biótipo suscetível. Menores áreas foliar e massa seca também foram registradas para o biótipo de C. bonariensis resistente ao glifosato quando comparado ao suscetível, porém com diferenças mais sutis que aquelas constatadas para C. canadensis. O crescimento absoluto do biótipo suscetível foi superior ao do resistente em ambas as espécies. A pressão de seleção para resistência ao glifosato teve impactos negativos na habilidade de crescimento dos biótipos.This work was carried out with the objective of comparing, under controlled and non-competitive condition, the growth of glyphosate-resistant and susceptible biotypes of Conyza canadensis and C. bonariensis; to quantify the effects of resistance selection pressure on the biotypes. Two trials were developed with treatments organized according to a factorial scheme 9 x 2, where nine were periodical growth evaluations and two were biotypes of each species. The variables evaluated per plant were: leaf area and dry mass (shoot, root and total; to determine absolute growth rate from the total dry mass. The glyphosate-resistant biotype of C. canadensis exhibits slower growth and smaller accumulation of leaf area

  18. Seleção de linhagens de melancia resistentes ao Watermelon mosaic virus e ao Papaya ringspot virus Selection of resistant watermelon lines to Watermelon mosaic virus and Papaya ringspot virus

    Directory of Open Access Journals (Sweden)

    José Evando Aguiar Beserra Júnior

    2007-10-01

    Full Text Available Foram avaliadas 20 linhagens de melancia, provenientes do cruzamento da cultivar comercial suscetível Crimson Sweet e da introdução PI 595201 resistente ao Watermelon mosaic virus (WMV e Papaya ringspot virus (PRSV-W. As linhagens, e os parentais foram inoculados com o WMV ou com o PRSV-W em casa-de-vegetação distintas. Aos 35 e 49 dias após a primeira inoculação (DAI, as plantas foram avaliadas por meio de uma escala de notas, em que 1 (ausência de sintomas a 5 (intenso mosaico e deformações foliares. Pelos resultados infere-se que, aos 35 DAI, as linhagens 1, 2 e 20 apresentaram resistência tanto para o WMV como para o PRSV-W, com médias de 1,95, 1,80 e 2,25 para o WMV, e de 2,50, 2,30 e 2,50 para o PRSV-W, respectivamente. As linhagens 5, 7 e 13 foram resistentes somente ao WMV e as plantas das linhagens 3, 10 e 18 para o PRSV-W. A reação das linhagens permaneceu em geral pouco alterada aos 49 DAI. A existência de linhagens resistentes somente ao WMV e somente ao PRSV-W, ao lado de linhagens resistentes a ambos os vírus, é indicativo de que as resistências ao WMV e ao PRSV-W não são controladas pelos mesmos genes.Twenty advanced watermelon breeding lines, derived from the cross between cv. Crimson Sweet (susceptible and PI 595201 (resistant to WMV and PRSV-W, were screened for resistance to both potyviruses. The twenty lines, among with Crimson Sweet and PI 595201, were inoculated with either WMV or PRSV-W, in two different greenhouse trials. Plants were evaluated for symptoms 35 and 49 days after the first inoculation (DAI, using a scale from 1 (no symptoms to 5 (severe mosaic and foliar distortion. Evaluations at 35 DAI indicated that lines 1, 2 and 20 had good levels of resistance to both WMV and PRSV-W, with ratings of 1,95, 1,80 and 2,25 for WMV, and of 2,50, 2,30 and 2,50 for PRSV-W, respectively. Lines 5, 7 and 13 were resistant to WMV only, whereas lines 3, 10 and 18 were resistant to PRSV-W only. The reaction of

  19. Presentación atípica de piomiositis tropical difusa de psoas por Staphylococcus aureus meticilino resistente Atypical presentation of diffuse tropical pyomiositis of the psoas due to methicillin resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Ray Ticse

    2012-03-01

    Full Text Available La piomiositis tropical difusa primaria es una enfermedad de presentación infrecuente en nuestro medio, con pocos casos asociados a Staphylococcus aureus meticilino resistente, adquirido en la comunidad (MRSA-AC. Se presenta el caso de un paciente de 70 años, con tratamiento irregular para diabetes mellitus tipo 2, que fue hospitalizado por presentar un cuadro de diez días de evolución, con dolor lumbar irradiado a miembro inferior izquierdo, fiebre y flexión forzada de la cadera derecha por dolor a la movilización. El diagnóstico de piomiositis difusa de ambos psoas se realizó con resonancia magnética. Del cultivo de una colección paravertebral posterior se aisló Staphylococcus aureus resistente a oxacilina, penicilina y dicloxacilina.Diffuse tropical primary pyomyositis is an infrequent entity in our country, with few cases associated to communityacquired Methicillin- resistant Staphylococcus aureus. There are no reported cases of Community-Acquired Methicillin- Resistant Staphylococcus aureus (CA- MRSA in Peru. We present the case of a 70 year old male with a previous diagnosis of type 2 diabetes mellitus, receiving irregular treatment, who was admitted to the hospital with a history of 10 days of low back pain radiating to the left leg, fever and forced flexion of the right hip due to pain during movement. The diagnosis of diffuse pyomyositis of both psoas muscles was performed with MRI and culture of a posterior paravertebral collection, from which Staphylococcus aureus resistant to oxacillin, penicillin and dicloxacillin was isolated.

  20. Análise comparativa entre tuberculose multirresistente e tuberculose extensivamente resistente – Epidemiologia e factores preditivos

    Directory of Open Access Journals (Sweden)

    Ana Sofia Vilariça

    2008-11-01

    Full Text Available Resumo: Introdução: A tuberculose extensivamente resistente (TBXDR define-se como uma forma de tuberculose multirresistente (TBMR com resistências adicionais às fluoroquinolonas e, pelo menos, a um dos antibacilares injectáveis seguintes: amicacina, canamicina e capreomicina. Foi classificada pela OMS como uma ameaça séria ao controlo da tuberculose, com consequências à escala mundial, assumindo os contornos de uma autêntica pandemia em algumas regiões do globo.Objectivo: Comparar os doentes com TBXDR versus outros perfis de TBMR no que diz respeito às características demográficas e epidemiológicas, factores etiopatogénicos e evolução no internamento.Material e métodos: Doentes internados no Serviço de Pneumologia III do Hospital de Pulido Valente no período compreendido entre Abril de 1999 e Junho de 2007, com o diagnóstico de TBMR microbiologicamente confirmado. Foram analisadas as seguintes variáveis: sexo, distribuição etária, raça, formas de apresentação da TB, grupos de tratamento, perfil de resistência aos antibacilares, estatuto de imigrante, número e duração de tratamentos anteriores, classificação OMS, co-infecção VIH, alcoolismo e/ou toxicodependência, demora média do internamento e mortalidade intra-hospitalar. A análise estatística realizou-se no programa SPSS (Statistical Package for the Social Sciences, versão 15.0. Nas variáveis categoriais, as diferenças estatísticas entre os grupos foram avaliadas através do teste qui-quadrado e as variáveis numéricas através do teste t. Para a construção do modelo preditivo da presença de TBXDR (variável dependente foi utilizada a análise de regressão logística, tendo sido incluídas as seguintes variáveis independentes: classificação OMS, coinfecção VIH, estatuto de imigrante, alcoolismo e/ou toxicodepend

  1. Colonização por Staphylococcus aureus resistente à meticilina: Que impacto na morbilidade de doentes pediátricos com fibrose quística?

    Directory of Open Access Journals (Sweden)

    Joana Fermeiro

    2010-07-01

    Full Text Available Resumo: Introdução: Ao Staphylococcus aureus resistente à meticilina (MRSA é classicamente reconhecido um papel patogénico no âmbito da fibrose quística (FQ.Objectivos: Avaliação da evolução da prevalência e incidência da colonização por MRSA, impacto clínico no ano após o primeiro isolamento, factores de risco e padrão de resistência antimicrobiana.Métodos: Estudo retrospectivo dos doentes pediátricos colonizados por MRSA seguidos no centro de FQ do Hospital de Santa Maria de 2003 a 2007.Resultados: O MRSA foi isolado em secreções respiratórias de 12 dos 60 doentes seguidos durante este período (colonização crónica em 3 doentes. A idade média à data do primeiro isolamento foi de 9 anos e 10 meses e o tempo médio entre o diagnóstico de FQ e a aquisição de MRSA de 5 anos e 7 meses.Verificou-se um aumento da prevalência e incidência de colonização por MRSA, com um máximo atingido em 2007 (prevalência 14,3% e incidência 8,9%. Quatro doentes cumpriram antibioticoterapia profiláctica antiestafilocócica com flucloxacilina.No ano após o primeiro isolamento de MRSA, constatou-se um aumento do número de dias de internamento em 4 doentes (2 com colonização crónica e deterioração da função pulmonar em 5, incluindo a totalidade dos doentes com colonização crónica. Apenas um doente apresentou diminuição de percentil de índice de massa corporal.As resistências mais frequentemente encontradas foram à rifampicina e à clindamicina.Conclusões: Este estudo revelou ocorrência de deterioração clínica relevante em doentes com colonização crónica por MRSA, reforçando a importância da implementação de estratégias eficazes e precoces de erradicação.Rev Port Pneumol 2010; XVI (4: 527-542 Abstract: Background: Methicillin-resistant Staphylococcus aureus (MRSA plays a well-recognised pathogenic role in cystic fibrosis (CF.Aims: To evaluate the prevalence and incidence of colonisation by MRSA

  2. Comportamiento de un cemento portland resistente a los sulfatos frente al agua desionizada y a disoluciones de sulfato de sodio y de sulfato de magnesio

    Directory of Open Access Journals (Sweden)

    Bermejo-Muñoz, M. Francisca

    1987-12-01

    Full Text Available Not available

    [es] En este trabajo se estudia el comportamiento de un cemento portland industrial resistente a los sulfatos cuando los lechos granulados —fabricados con dicho cemento, una vez hidratado y conservado durante 7 y 28 días en una cámara húmeda a 21 ± 2 °C y con una humedad relativa superior al 90%— se someten a la acción del agua desionizada, de una disolución de sulfato de sodio y de otra disolución de sulfato de magnesio habiendo determinado: a. la evolución de los contenidos de los iones Ca (II y SO4 (II en los dos primeros casos, y además Mg (II, en el tercero, en las disoluciones que han atravesado los lechos de cemento, así como la del pH y de la conductividad, b. la variación del contenido de los iones mencionados en los compuestos correspondientes del cemento de los lechos, una vez sometidos a la acción de las disoluciones agresivas, así como las modificaciones estructurales experimentadas, y c. las características estructurales de la nueva fase sólida formada en las fracciones recogidas de la disolución de sulfato de magnesio, que han atravesado los lechos de cemento. En estos trabajos se ha puesto de manifiesto que la cantidad de Ca(OH2 disuelta (extraída tanto por el agua desionizada, como por la disolución de sulfato de sodio, disminuye exponencialmente a medida que aumenta el volumen de estas disoluciones, que han atravesado los lechos de cemento, alcanzando un valor asintótico; este fenómeno influye en el avance de las reacciones de hidratación y en la degradación de los compuestos del cemento. En el caso de la disolución de sulfato de magnesio, se produce un intercambio entre los iones Ca (II del Ca(OH2 del cemento hidratado y el Mg (II de la disolución, el cual precipita como brucita en el lecho —llegando a colmatarlo en determinados casos— y en las fracciones de la disolución que han atravesado los lechos. La disolución del Ca(OH2

  3. Seasonal variations in CO2 and CH4 fluxes of four different plant compositions of a Sphagnum-dominated Alpine peat bog

    Science.gov (United States)

    Drollinger, Simon; Maier, Andreas; Karer, Jasmin; Glatzel, Stephan

    2017-04-01

    Peatlands are the only type of ecosystems which have the ability to accumulate significant amounts of carbon (C) under undisturbed conditions. The amount of C sequestered in peatlands depends on the balance between gross primary production, ecosystem respiration and decomposition of plant material. Sphagnum-dominated bogs possess the greatest peat accumulation potential of all peatlands, thus in turn, feature highest C release potentials. Many studies report about the C balances of undisturbed northern peat bogs, however, little is known about the effects of peatland degradation on the C balance between different plant compositions within peat bog ecosystems. Particularly in the Alpine region, where temperature increase during the last century has been almost twice as high as the global mean. The investigated peat bog is located in the inner Alpine Enns valley in the Eastern Alps, Austria (N 47˚ 34.873' E 14˚ 20.810'). It is a pine peat bog covered by Sphagnum mosses and a present extent of about 62 ha. Due to increasing differences in surface height of the peatland compared to the surrounding areas and related lowered water retention capacity attributed to the subsidence of the adjacent intensively managed meadows on deeply drained peat soils, the function of the peatland as a carbon sink is strongly endangered. Hence, the current mean water table depth of the central peat bog area is about -12 cm. To reveal differences in peatland-atmosphere C exchanges within the peatland ecosystem, we investigated CO2 and CH4 fluxes of four different vegetation compositions (PM1-PM4) at the treeless central peat bog area. PM1 is dominated by the graminoids Rhynchospora alba and Eriophorum vaginatum. PM2 is inhabited by small individuals (< 35 cm) of the conifer Pinus mugo, whereas PM3 is dominated by the ericaceous plant Calluna vulgaris. PM4 again is populated by Pinus mugo, but higher growing (35 - 60 cm) and with corresponding higher amount of biomass. Fluxes were measured

  4. Nebela jiuhuensis nov. sp. (Amoebozoa; Arcellinida; Hyalospheniidae): A New Member of the Nebela saccifera - equicalceus - ansata Group Described from Sphagnum Peatlands in South-Central China.

    Science.gov (United States)

    Qin, Yangmin; Man, Baiying; Kosakyan, Anush; Lara, Enrique; Gu, Yansheng; Wang, Hongmei; Mitchell, Edward A D

    2016-09-01

    Hyalospheniids are among the most common and conspicuous testate amoebae in high-latitude peatlands and forest humus. These testate amoebae were widely studied as bioindicators and are increasingly used as models in microbial biogeography. However, data on their diversity and ecology are still very unevenly distributed geographically: notably, data are lacking for low-latitude peatlands. We describe here a new species, Nebela jiuhuensis, from peatlands near the Middle Yangtze River reach of south-central China with characteristic morphology. The test (shell) has hollow horn-like lateral extensions also found in N. saccifera, N. equicalceus (=N. hippocrepis), and N. ansata, three large species restricted mostly to Sphagnum peatlands of Eastern North America. Mitochondrial cytochrome oxidase (COI) data confirm that N. jiuhuensis is closely related to the morphologically very similar North American species N. saccifera and more distantly to N. ansata within the N. penardiana group. These species are all found in wet mosses growing in poor fens. Earlier reports of morphologically similar specimens found in South Korea peatlands suggest that N. jiuhuensis may be distributed in comparable peatlands in Eastern Asia (China and Korea). The discovery of such a conspicuous new species in Chinese peatlands suggests that many new testate amoebae species are yet to be discovered, including potential regional endemics. Furthermore, human activities (e.g., drainage, agriculture, and pollution) have reduced the known habitat of N. jiuhuensis, which can thus be considered as locally endangered. We, therefore, suggest that this very conspicuous micro-organism with a probably limited geographical distribution and specific habitat requirement should be considered as a flagship species for microbial biogeography as well as local environmental conservation and management. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  5. Local adaptations in bryophytes revisited: the genetic structure of the calcium-tolerant peatmoss Sphagnum warnstorfii along geographic and pH gradients

    Science.gov (United States)

    Mikulášková, Eva; Hájek, Michal; Veleba, Adam; Johnson, Matthew G; Hájek, Tomáš; Shaw, Jonathan A

    2015-01-01

    Bryophytes dominate some ecosystems despite their extraordinary sensitivity to habitat quality. Nevertheless, some species behave differently across various regions. The existence of local adaptations is questioned by a high dispersal ability, which is thought to redistribute genetic variability among populations. Although Sphagnum warnstorfii is an important ecosystem engineer in fen peatlands, the causes of its rather wide niche along the pH/calcium gradient are poorly understood. Here, we studied the genetic variability of its global populations, with a detailed focus on the wide pH/calcium gradient in Central Europe. Principal coordinates analysis of 12 polymorphic microsatellite loci revealed a significant gradient coinciding with water pH, but independent of geography; even samples from the same fens were clearly separated along this gradient. However, most of the genetic variations remained unexplained, possibly because of the introgression from phylogenetically allied species. This explanation is supported by the small heterogeneous cluster of samples that appeared when populations morphologically transitional to S. subnites, S. rubellum, or S. russowii were included into the analysis. Alternatively, this unexplained variation might be attributed to a legacy of glacial refugia with recently dissolved ecological and biogeographic consequences. Isolation by distance appeared at the smallest scale only (up to 43 km). Negative spatial correlations occurred more frequently, mainly at long distances (up to 950 km), implying a genetic similarity among samples which are very distant geographically. Our results confirm the high dispersal ability of peatmosses, but simultaneously suggested that their ability to cope with a high pH/calcium level is at least partially determined genetically, perhaps via specific physiological mechanisms or a hummock-forming ability. PMID:25628880

  6. A comparison of lead pollution record in Sphagnum peat with known historical Pb emission rates in the British isles and the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Novak, M.; Erel, Y.; Zemanova, L.; Bottrell, S.H.; Adamova, M. [Czech Geological Survey, Prague (Czech Republic)

    2008-12-15

    Vertical Pb concentration gradients and isotope ratios (Pb-206/Pb-207, Pb-208/Pb-207) are reported for five Pb-210-dated Sphagnum peat profiles. The studied peat bogs are in the British Isles (Thorne Moors, England; Mull, Scotland; and Connemara, Eire) and central Europe (Ocean, northern Czech Republic: Rybarenska slat, southern Czech Republic). Both the U.K. and the Czech Republic experienced maximum Pb emissions from Ag-Pb smelting around 1880. Pb emissions from coal burning peaked in 1955 in the U.K, and in the 1980s in the Czech Republic. In both countries, use of alkyl-lead additives to gasoline resulted in large Pb emissions between 1950 and 2000. We hypothesized that peaks in Pb emissions from smelting, coal burning and gasoline burning, respectively, should be mirrored in the peat profiles. However, a more complicated pattern emerged. Maximum annual Pb accumulation rates occurred in 1870 at Ocean, 1940 at Thorne Moors, 1988 at Rybarenska slat, and 1990 at Mull and Connemara. Atmospheric Pb inputs decreased in the order Thorne Moors {ge} Ocean > Rybarenska slat > Mull > Connemara. The Ocean bog was unique in the central European region in that its maximum Pb pollution dated back to the 19th century and coincided with maximum Pb smelting at Freiberg and Pribram. In contrast, numerous previously studied sites showed no Pb accumulation maximum in the 19th century, but increasing pollution until the 1980s. It remains unclear why Ocean did not record the regional peak in Pb emissions caused by high coal and gasoline burning around 1980, while an array of nearby bogs studied previously did record the 1980 coal/gasoline peak, but no 1880 smelting peak. Mean Pb-206/Pb-207 ratios of potential pollution sources were 1.07 and 1.11 for gasoline, 1.17 and 1.17 for local ores, and 1.18 and 1.19 for coal in the U.K. and the Czech Republic, respectively.

  7. Informing innovative peatland conservation in light of palaeoecological evidence for the demise of Sphagnum imbricatum: the case of Oxenhope Moor, Yorkshire, UK

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    J. McCarroll

    2016-04-01

    Full Text Available Actively growing mires have high conservation value and the potential to sequester carbon. However, drainage, burning, overgrazing and atmospheric pollution have led to depauperation of native flora and loss of peat at many peatland sites. In order to counteract such degradation, palaeoecological techniques can be applied and the data then used to inform nature conservation practice. The present study exemplifies this approach and was conducted on degraded blanket mire in Yorkshire, UK, in collaboration with a field-based moorland restoration agency. High-resolution, multiproxy palaeoecological analyses on a peat core from Oxenhope Moor were used to reconstruct Holocene vegetation changes spanning approximately the last 7000 years. Humification, pollen, plant macrofossil and charcoal analyses show distinct changes in species composition and indicate their potential causes. Human-induced changes identified at 2100 cal. BP are most likely to reflect deliberate clearance by fire. Sphagnum imbricatum disappears and is subsequently replaced by S. papillosum at ca. 1000 cal. BP, possibly due to drier conditions and competition between the two species. Increased human activity is identified since the Industrial Revolution where monocots and Eriophorum vaginatum increase, interpreted as a result of managed burning. It is intended that the long-term ecological history of the site, derived using palaeoecological techniques, will be used to inform conservation practice and can help set feasible targets for restoration and conservation. Specifically, encouraging a species mix that has pre-19th century longevity is suggested, including the specific recommendation that translocation of S. imbricatum be explored experimentally at this site, with a view to ascertaining likely success elsewhere.

  8. Control of glyphosate resistant hairy fleabane (Conyza bonariensis with dicamba and 2,4-D Controle de buva (Conyza bonariensis resistente ao glyphosate com dicamba e 2,4-D

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    D.J. Soares

    2012-06-01

    Full Text Available Auxyn type herbicides such as dicamba and 2,4-D are alternative herbicides that can be used to control glyphosate-resistant hairy fleabane. With the forthcoming possibility of releasing dicamba-resistant and 2,4-D-resistant crops, use of these growth regulator herbicides will likely be an alternative that can be applied to the control of glyphosate resistant hairy fleabane (Conyza bonariensis. The objective of this research was to model the efficacy, through dose-response curves, of glyphosate, 2,4-D, isolated dicamba and glyphosatedicamba combinations to control a brazilian hairy fleabane population resistant to glyphosate. The greenhouse dose-response studies were conducted as a completely randomized experimental design, and the rates used for dose response curve construction were 0, 120, 240, 480, 720 and 960 g a.i. ha-1 for 2,4-D, dicamba and the dicamba combination, with glyphosate at 540 g a.e. ha-1. The rates for glyphosate alone were 0, 180, 360, 540, 720 and 960 g a.e. ha-1. Herbicides were applied when the plants were in a vegetative stage with 10 to 12 leaves and height between 12 and 15 cm. Hairy fleabane had low sensitivity to glyphosate, with poor control even at the 960 g a.e. ha-1 rate. Dicamba and 2,4-D were effective in controlling the studied hairy fleabane. Hairy fleabane responds differently to 2,4-D and dicamba. The combination of glyphosate and dicamba was not antagonistic to hairy fleabane control, and glyphosate may cause an additive effect on the control, despite the population resistance.Os herbicidas mimetizadores de auxinas como dicamba e 2,4-D são alternativas para o controle de buva resistente ao glyphosate. Com a possível futura liberação comercial de culturas resistentes ao dicamba e 2,4-D, a aplicação destes herbicidas reguladores de crescimento será uma provável alternativa de controle de buva resistente ao glyphosate. O objetivo desta pesquisa foi modelar por meio de curvas de dose-resposta a efic

  9. Inhibición de la expresión del sistema agr de Staphylococcus aureus resistente a meticilina mediante el uso de polifenoles totales de hojas de aguacate mexicano ( Persea americana var. drymifolia

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    M.A. García-Moreno

    2017-01-01

    Full Text Available Introducción : La resistencia a los antibióticos por parte de las bacterias está provocando gran impacto negativo en la salud humana y en la producción animal. Actualmente, Staphylococcus aureus es considerada dentro de los seis principales grupos bacterianos con mayores reportes de aparición de resistencia a nivel mundial . Por otro lado , durante décadas las plantas de uso medicinal han sido fuente importante de compuestos bactericida s ; sin embargo, también se ha empezado a documentar otras moléculas con otros mecanismos antimicrobianos , como es la inhibici ón de la percepción de quórum ( anti - p ercepción de q u ó rum ( APQ . En la medicina tradicional mexicana las hojas de aguacate mexicano ( Persea americana var drymifolia han sido empleadas para tratar diversos padecimientos que involucran infecciones bacterianas, por lo que es factible contenga compuesto s que pose a n efectos antioxidantes , bactericidas y APQ, que ayuden a combat ir las infecciones de cepas resistentes. De t al manera , que e l objetivo de esta investigación fue determinar el efecto de los polifenoles totales de las hojas de Persea americana var. drymifolia y su actividad APQ sobre cepas de S. aureus resistente s a meticilina (MRSA . Método s : Se obtuvieron l os polifenoles presente s en las hojas de 18 cultivares de aguacate mexicano mediante extracción asistida por ultrasonido y fueron purificados en una columna de amberlita . E stos polifenoles fueron analizados funcionalmente y evaluados contra cepas de S. aureu s MRSA para determinar su efecto APQ sobre el sistema denominado Agr . Resultados : Los polifenoles extraídos de las hojas de aguacate de raza mexicana exhiben una fuerte actividad bactericida . D e los 18 cultivares probados, la variedad María Elena fue la que presentó el mayor efecto , exhibiendo una CMI de 116 μg∙ mL - 1 y un CMB de 133 μg∙ mL - 1 contra la cepa de MRSA μ3 . Sin embargo, también logran inhibir los niveles

  10. Eficacia de algunos biocidas contra estafilococos hospitalarios sensibles y resistentes a la meticilina en la provincia de Buenos Aires, Argentina Efficacy of biocides against hospital isolates of Staphylococcus sensitive and resistant to methicillin, in the province of Buenos Aires, Argentina

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    Mirta Beatriz Reynaldo

    2004-09-01

    Full Text Available OBJETIVOS: Evaluar cómo responden los estafilococos hospitalarios sensibles y resistentes a la meticilina ante la acción de diferentes antisépticos y desinfectantes empleados habitualmente en los hospitales de la Provincia de Buenos Aires, Argentina. Demostrar la eficacia de esas sustancias mediante la determinación de sus concentraciones bactericidas eficaces, así como analizar si existe correlación entre la resistencia a biocidas y la resistencia a la meticilina en esta población bacteriana. MÉTODOS: Se evaluó la acción de siete biocidas con 25 cepas de estafilococos nosocomiales sensibles y resistentes a la meticilina y una cepa de colección, Staphylococcus aureus ATCC 6538. Las cepas hospitalarias provienen de dos hospitales de máxima complejidad y fueron obtenidas, durante los meses de abril de 2000 a mayo de 2002, de muestras clínicas (hemocultivo, urocultivo, punta de catéter y abceso pertenecientes a pacientes de ambos sexos, internados y ambulatorios. Después del aislamiento de dichas cepas, determinamos la sensibilidad a antibióticos mediante el método de difusión en agar de Kirby y Bauer. Para estudiar la acción de los biocidas de uso hospitalario sobre estas cepas, empleamos el ensayo de Kelsey-Sykes, que permite establecer las concentraciones bactericidas eficaces de tales compuestos. RESULTADOS: Los resultados muestran que la respuesta de las cepas hospitalarias resistentes y sensibles a la meticilina varía con respecto a la cepa de colección. El digluconato de clorhexidina, la yodopovidona, la tintura de yodo débil y el glutaraldehído alcalino fueron eficaces contra la mayoría de las cepas, independientemente de su resistencia o sensibilidad a los antibióticos. CONCLUSIONES: Estas evaluaciones no indican ninguna asociación entre la resistencia a la meticilina y la resistencia a los biocidas evaluados. Asimismo, apuntan a la necesidad de seguir investigando para valorar la eficacia de los agentes qu

  11. Seleção de clones de batata-doce resistentes a Meloidogyne incognita raça 1 Selection of sweetpotato clones resistant to Meloidogyne incognita race 1

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    Aline Marchese

    2010-09-01

    Full Text Available O objetivo deste trabalho foi selecionar clones de batata-doce (Ipomoea batatas resistentes à raça 1 de Meloidogyne incognita e avaliar a eficiência do método de seleção empregado, pela estimação dos coeficientes de variação genética e ambiental e das herdabilidades no sentido amplo. Foram utilizados 123 genótipos de batata-doce, entre os quais quatro cultivares comerciais - Brazlândia Rosada, Brazlândia Roxa, Brazlândia Branca e Palmas -, e 119 acessos previamente selecionados no programa de melhoramento vegetal da Universidade Federal de Lavras. O delineamento experimental utilizado foi o de blocos aumentados, com três tratamentos comuns: as cultivares de batata-doce Brazlândia Branca e Palmas, e a cultivar de tomate Santa Clara, suscetível ao nematoide. A classificação dos níveis de resistência foi realizada de acordo com o fator de reprodução do nematoide e o índice de reprodução relativo à cultivar Santa Clara, de tomateiro. A relação entre os coeficientes de variação genética e ambiental e as herdabilidades no sentido amplo foram altas, tanto para o fator de reprodução quanto para o índice de reprodução dos nematoides, o que demonstra a eficiência do método empregado para a seleção de genótipos resistentes. Foram identificados 57 genótipos promissores de batata-doce, resistentes à raça 1 de M. incognita, e selecionados para continuar no programa de melhoramento.The objective of this work was to select sweetpotato (Ipomoea batatas resistant clones to Meloidogyne incognita race 1, and to assess the efficiency of the selection method deployed, through the estimation of genetic and environmental coefficients of variation, and broad-sense heritabilities. Genotypes assessed comprised 123 sweetpotato entries altogether, including four commercial cultivars - Brazlândia Rosada, Brazlândia Roxa, Brazlândia Branca, Palmas - and 119 clones previously selected by the Universidade Federal de Lavras

  12. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    Science.gov (United States)

    Tsyganov, Andrey N; Aerts, Rien; Nijs, Ivan; Cornelissen, Johannes H C; Beyens, Louis

    2012-05-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming, winter snow addition solely and winter snow addition together with spring warming on testate amoeba assemblages after eight years of experimental field climate manipulations. All manipulations were accomplished using open top chambers in a dry blanket bog located in the sub-Arctic (Abisko, Sweden). We estimated sensitivity of abundance, diversity and assemblage structure of living and empty shell assemblages of testate amoebae in the living and decaying layers of Sphagnum. Our results show that, in a sub-arctic climate, testate amoebae are more sensitive to climate changes in the growing season than in winter. Summer warming reduced species richness and shifted assemblage composition towards predominance of xerophilous species for the living and empty shell assemblages in both layers. The higher soil temperatures during the growing season also decreased abundance of empty shells in both layers hinting at a possible increase in their decomposition rates. Thus, although possible effects of climate changes on preservation of empty shells should always be taken into account, species diversity and structure of testate amoeba assemblages in dry subarctic bogs are sensitive proxies for climatic changes during the growing season. Copyright © 2011 Elsevier GmbH. All rights reserved.

  13. Habilidade competitiva de plantas de arroz com biótipos de capim-arroz resistente ou suscetível ao quinclorac Competitive ability of rice plants with barnyardgrass biotypes resistant or susceptible to quinclorac

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    S.P. Tironi

    2009-06-01

    Full Text Available Objetivou-se com este trabalho avaliar a habilidade competitiva de plantas de arroz cultivar BRS Pelota com biótipos de capim-arroz resistente ou suscetível ao herbicida quinclorac. Para isso, foi instalado experimento em casa de vegetação, em delineamento completamente casualizado com quatro repetições, sendo os tratamentos dispostos em esquema fatorial 2 x 6. As unidades experimentais constaram de vasos plásticos contendo 10 dm³ de solo, cujo pH e nível de nutrientes foram previamente corrigidos. Os tratamentos consistiram na competição entre uma planta de arroz, cultivar BRS Pelota, com populações (0, 1, 2, 3, 4 ou 5 plantas por vaso dos biótipos de capim-arroz resistente (ECH-13 ou suscetível (ECH-12 ao herbicida quinclorac. As avaliações foram realizadas aos 40 dias após emergência, sendo avaliados; massa seca da parte aérea (MSPA, taxa de crescimento (TC, área foliar específica (AFE, razão de massa foliar (RMF, razão de área foliar (RAF e índice de área foliar (IAF. A interferência no desenvolvimento do cultivar de arroz BRS Pelota foi proporcionalmente maior com o aumento da população de ambos os biótipos de capim-arroz. Os biótipos apresentaram, em geral, habilidade competitiva similar.The objective of this study was to evaluate the competitive ability of the rice cultivar BRS Pelota with biotypes resistant or susceptible to the herbicide Quinclorac. The experiment was conducted under greenhouse conditions in a completely randomized design with four replications, with the treatments arranged in a 2 x 6 factorial. The experimental units consisted of plastic pots containing 10 dm³ of soil, with pH and nutrient level being previously corrected. The treatments consisted of a competition between a rice plant, BRS Pelota cultivar, with populations (0, 1, 2, 3, 4 or 5 plants per pot of the barnyardgrass biotypes resistant (ECH-13 or susceptible (ECH -12 to the herbicide Quinclorac. The evaluations were performed

  14. Características físico-quimicas, análise sensorial e conservação de frutos de cultivares de bananeira resistentes à sigatoca-negra

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    Célia Lúcia Siqueira

    2010-10-01

    Full Text Available O cultivar Prata Anã é o mais plantada no Norte de Minas Gerais, o que demonstra estar a bananicultura regional baseada numa variedade suscetível à sigatoca-negra. Apesar de existirem cultivares resistentes em fase de recomendação para o cultivo na região, ainda são escassos os trabalhos relacionados a metodologias de conservação pós-colheita. Assim, o objetivo deste trabalho foi avaliar o período de armazenamento e as características físico-químicas e sensoriais dos cultivares de bananeira Fhia - 02 e Precioso, ambos resistentes à sigatoca-negra, e o efeito da atmosfera modificada associada à refrigeração. Foram realizados três experimentos, o primeiro em temperatura ambiente, o segundo a 12 ºC e o terceiro a 15 ºC. Esses experimentos foram instalados no delineamento em blocos casualizados em esquema de parcelas subdivididas no tempo, tendo nas parcelas um fatorial 2 (com e sem embalagem x 2 (Fhia - 02 e Precioso e nas subparcelas as avaliações em intervalo de seis e dois dias para frutos armazenados nas temperaturas de 12, 15 e 25 ºC, com quatro repetições e três frutos por unidade experimental. Após o tratamento, os frutos foram dispostos em bandejas de poliestireno expandido (sem embalagem e embalagens de 10 e 16 µm e umidade relativa de 90%. As características avaliadas foram: tamanho, diâmetro, cor, firmeza, perda de matéria fresca, sólidos solúveis totais (SST, acidez total titulável (ATT, SST/ATT, pH e análise sensorial. O uso da embalagem associada à refrigeração permitiu armazenar os frutos por 28 dias, mantendo as características físico-químicas.

  15. Aceitação de cultivares de bananas resistentes à Sigatoka Negra junto ao consumidor da região Nordeste do Brasil Acceptance of banana cultivars resistant to Black Sigatoka by the consumer market of Northeast Brazilian region

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    Deborah dos Santos Garruti

    2012-05-01

    Full Text Available O Mal da Sigatoka Negra é devastador para as cultivares tradicionais de banana. No Brasil, cultivares resistentes estão sendo desenvolvidas, mas se a preferência do consumidor não for considerada, o programa de melhoramento pode falhar. Neste trabalho, a aceitabilidade de quatro cultivares resistentes foi acessada no Nordeste brasileiro e comparada a quatro variedades comerciais. Dois grupos de consumidores participaram: adultos jovens e donas de casa. Escala hedônica foi aplicada para aparência externa dos cachos, aceitação global e aceitação por atributos dos frutos (aparência sem a casca, aroma, sabor e textura, além de testes de preferência e intenção de compra. Os dados foram submetidos à ANOVA e Mapa de Preferência Interno. Mulheres e jovens mostraram opiniões semelhantes. As cultivares 'Preciosa' e 'Pacovan Ken' mostraram ser as mais promissoras, sendo que a primeira já pode substituir as cultivares comerciais 'Prata' e 'Pacovan' sem prejudicar a sua aceitabilidade, mas a 'Pacovan Ken' ainda precisa ser melhorada quanto à aparência.The Black Sigatoka Disease is devastating to traditional banana cultivars. In Brazil, resistant cultivars are being developed but if the consumer's preference is not taken into account, the breeding program may not succeed. In this research the acceptability of four resistant cultivars was accessed in the Northeastern Brazilian region and compared to four commercial varieties. Two groups of consumers participated: young adults and housewives. Hedonic scale was applied to external appearance of bunches, global acceptance and acceptance of fruits' attributes (appearance without peel, aroma, flavor and texture. Preference and purchase intent were also evaluated. Data were submitted to ANOVA and Preference Mapping. Women and young adults showed similar opinions. 'Preciosa' and 'Pacovan Ken' cultivars showed to be the most promising ones. 'Preciosa' can already substitute the commercial 'Prata

  16. Alkali-resistant glass fiber reinforced high strength concrete in simulated aggressive environment; Hormigón de altas resistencia reforzado con fibras de vidrio resistentes a alcalis en ambientes agresivos simulados.

    Energy Technology Data Exchange (ETDEWEB)

    Kwan, W.H.; Cheah, C.B.; Ramli, M.; Chang, K.Y.

    2018-04-01

    The durability of the alkali-resistant (AR) glass fiber reinforced concrete (GFRC) in three simulated aggresive environments, namely tropical climate, cyclic air and seawater and seawater immersion was investigated. Durability examinations include chloride diffusion, gas permeability, X-ray diffraction (XRD) and scanning electron microscopy examination (SEM). The fiber content is in the range of 0.6 % to 2.4 %. Results reveal that the specimen containing highest AR glass fiber content suffered severe strength loss in seawater environment and relatively milder strength loss under cyclic conditions. The permeability property was found to be more inferior with the increase in the fiber content of the concrete. This suggests that the AR glass fiber is not suitable for use as the fiber reinforcement in concrete is exposed to seawater. However, in both the tropical climate and cyclic wetting and drying, the incorporation of AR glass fiber prevents a drastic increase in permeability. [Spanish] Este trabajo se centra en el estudio de la durabilidad de hormigón reforzado con fibra de vidrio resistente a álcalis (CRFVRA) en tres ambientes agresivos simulados como son, condiciones de clima tropical, ciclos de aire y agua de mar e inmersión marina. Los tests de durabilidad incluyeron la difusión de cloruros, permeabilidad de gas, difracción de rayos X (XRD) y evaluacion por microscopía electrónica de barrido (SEM). Los contenidos de fibra evaluados estuvieron en el rango desde 0.6% hasta 2.4%. Los resultados revelan que la muestra que contiene el mayor porcentaje de fibra sufre una severa pérdida de resistencia en condiciones de agua de mar, y una menor disminución de resistencia bajo condiciones cíclicas. Su permeabilidad disminuyó al incrementar el contenido de fibras en el hormigón. Lo anterior sugiere que el refuerzo con fibra resistente a alcalinos no es adecuado para su uso en hormigón en ambiente de agua de mar. Sin embargo, bajo condiciones de clima

  17. Oxacilin-resistant Coagulase-negative staphylococci (CoNS bacteremia in a general hospital at São Paulo city, Brasil Bacteremias por Staphylococcus coagulase negativos oxacilina resistentes em um hospital na cidade de São Paulo, Brasil

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    P.A. D'Azevedo

    2008-12-01

    Full Text Available In the last decades, coagulase-negative staphylococci (CoNS, especially Staphylococcus epidermidis have become an important cause of bloodstream infections. In addition, rates of methicillin-resistance among CoNS have increased substantially, leading to the use of glicopeptides for therapy. The objective of this study was to evaluate eleven consecutives clinically relevant cases of oxacillin-resistant CoNS bacteremia in a general hospital localized in São Paulo city, Brazil. Five different species were identified by different phenotypic methods, including S. epidermidis (5, S. haemolyticus (3, S. hominis (1, S. warneri (1 and S. cohnii subsp urealyticus (1. A variety of Pulsed Field Gel Electrophoresis profiles was observed by macrorestriction DNA analysis in S. epidermidis isolates, but two of three S. haemolyticus isolates presented the same profile. These data indicated the heterogeneity of the CoNS isolates, suggesting that horizontal dissemination of these microorganisms in the investigated hospital was not frequent. One S. epidermidis and one S. haemolyticus isolates were resistant to teicoplanin and susceptible to vancomycin. The selective pressure due to the use of teicoplanin in this hospital is relevant.Staphylococcus coagulase negativos (SCoN, especialmente Staphylococcus epidermidis tem se tornado causa importante de infecções da corrente circulatória nas últimas décadas. Além disso, percentuais de resistência a meticilina entre os SCoN têm aumentado significativamente, levando ao uso de glicopeptídeos nestes pacientes. O objetivo deste estudo foi avaliar onze casos consecutivos de bacteremia clinicamente relevantes por SCoN oxacilina resistentes em um hospital localizado na cidade de São Paulo, Brasil. Cinco diferentes espécies foram identificadas por diferentes métodos fenotípicos, incluindo S. epidermidis (5, S. haemolyticus (3, S. hominis (1, S. warneri (1 e S. cohnii subsp urealyticus (1. Diferentes perfis

  18. Methylocystis bryophila sp. nov., a facultatively methanotrophic bacterium from acidic Sphagnum peat, and emended description of the genus Methylocystis (ex Whittenbury et al. 1970) Bowman et al. 1993.

    Science.gov (United States)

    Belova, Svetlana E; Kulichevskaya, Irina S; Bodelier, Paul L E; Dedysh, Svetlana N

    2013-03-01

    A novel species is proposed for two facultatively methanotrophic representatives of the genus Methylocystis, strains H2s(T) and S284, which were isolated from an acidic (pH 4.3) Sphagnum peat-bog lake (Teufelssee, Germany) and an acidic (pH 3.8) peat bog (European North Russia), respectively. Cells of strains H2s(T) and S284 are aerobic, Gram-negative, non-motile, curved coccoids or short rods that contain an intracytoplasmic membrane system typical of type-II methanotrophs. They possess both a soluble and a particulate methane monooxygenase (MMO); the latter is represented by two isozymes, pMMO1 and pMMO2. The preferred growth substrates are methane and methanol. In the absence of C1 substrates, however, these methanotrophs are capable of slow growth on acetate. Atmospheric nitrogen is fixed by means of an aerotolerant nitrogenase. Strains H2s(T) and S284 grow between pH 4.2 and 7.6 (optimum pH 6.0-6.5) and at 8-37 °C (optimum 25-30 °C). The major fatty acids are C18 : 1ω8c, C18 : 1ω7c and C16 : 1ω7c; the major quinone is Q-8. The DNA G+C content is 62.0-62.3 mol%. Strains H2s(T) and S284 share identical 16S rRNA gene sequences, which displayed 96.6-97.3 % similarity to sequences of other taxonomically characterized members of the genus Methylocystis. Therefore, strains H2s(T) and S284 are classified as members of a novel species, for which the name Methylocystis bryophila sp. nov. is proposed; strain H2s(T) ( = DSM 21852(T)  = VKM B-2545(T)) is the type strain.

  19. Fimbriiglobus ruber gen. nov., sp. nov., a Gemmata-like planctomycete from Sphagnum peat bog and the proposal of Gemmataceae fam. nov.

    Science.gov (United States)

    Kulichevskaya, Irina S; Ivanova, Anastasia A; Baulina, Olga I; Rijpstra, W Irene C; Sinninghe Damsté, Jaap S; Dedysh, Svetlana N

    2017-02-01

    An aerobic, budding, dark pink to red-pigmented bacterium was isolated from an acidic boreal Sphagnum peat bog and designated strain SP5T. Cells of this strain were non-motile spheres that were uniformly covered with crateriform pits and fimbria, and tended to form aggregates during growth in liquid media. Strain SP5T was capable of growth between pH 4.0 and pH 6.8 (optimum at pH 5.5-6.0) and at temperatures between 10 and 30 °C (optimum at 20-25 °C). The preferred growth substrates were sugars and some heteropolysaccharides. The major fatty acids were C20 : 1ω9c, C16 : 1ω9c and C16 : 0, and the major polar lipid was trimethylornithine. Cells contained also significant amounts of bound (ω-1)OH-C30 : 1 fatty acid. The quinone was menaquinone-6, and the G+C content of the DNA was 60.7 mol%. Strain SP5T was a member of the order Planctomycetales and belonged to the phylogenetic lineage defined by the genus Gemmata. It displayed 88 and 89 % 16S rRNA gene sequence similarity to Gemmata obscuriglobusUQM 2246T and 'Gemmata massiliana' IIL30, 89 % to Zavarzinella formosa A10T and 86 % to Telmatocola sphagniphila SP2T. However, strain SP5T differed from members of these genera by cell morphology, substrate utilization pattern and fatty acid composition. Based on these data, the novel isolate should be considered as representing a novel species of a new genus of planctomycetes, for which the name Fimbriiglobus ruber gen. nov., sp. nov, is proposed. The type strain is SP5T (=LMG 29572T=VKM B-3045T). We also suggest the establishment of a novel family, Gemmataceaefam. nov., which includes the phylogenetically related genera Gemmata, Zavarzinella, Telmatocola and Fimbriiglobus.

  20. How do climate and human impact affect Sphagnum peatlands under oceanic-continental climatic conditions? 2000 years of fire and hydrological history of a bog in Northern Poland

    Science.gov (United States)

    Marcisz, Katarzyna; Tinner, Willy; Colombaroli, Daniele; Kołaczek, Piotr; Słowiński, Michał; Fiałkiewicz-Kozieł, Barbara; Lamentowicz, Mariusz

    2014-05-01

    Climate change affects many natural processes and the same applies to human impact For instance climate change and anthropogenic activities may cause increased fire activity or change peatland dynamics. Currently it is still unknown how Sphagnum peatlands in the oceanic-continental transition zone of Poland may respond to combined effects of heat waves, drought and fire. The aim of the study was to reconstruct the last 2000 years palaeohydrology and fire history at Linje bog in Northern Poland. The main task was to determine the drivers of fire episodes, particularly to identify climatic and anthropogenic forcing. A two-meter peat core was extracted and subsampled with a high resolution. Micro- and macroscopic charcoal analyses were applied to determine past fire activity and the results compared with palaeohydrological reconstructions based on testate amoeba analysis. Palynological human indicators were used to reconstruct human activity. A depth-age model including 20 14C dates was constructed to calculate peat accumulation rates and charcoal influx. We hypothesised that: 1) fire frequency in Northern Poland was determined by climatic conditions (combination of low precipitation and heat waves), as reflected in peatland water table, and that 2) past fire episodes in the last millennium were intensified by human activity. Furthermore climate may have influenced human activity over harvest success and the carrying capacity. Our study shows that fire was important for the studied ecosystem, however, its frequency has increased in the last millennium in concomitance with land use activities. Landscape humanization and vegetation opening were followed by a peatland drying during the Little Ice Age (from ca. AD 1380). Similarly to other palaeoecological studies from Poland, Linje peatland possessed an unstable hydrology during the Little Ice Age. Increased fire episodes appeared shortly before the Little Ice Age and most severe fires were present in the time when

  1. A comparison of lead pollution record in Sphagnum peat with known historical Pb emission rates in the British Isles and the Czech Republic

    Science.gov (United States)

    Novak, Martin; Erel, Yigal; Zemanova, Leona; Bottrell, Simon H.; Adamova, Marie

    Vertical Pb concentration gradients and isotope ratios ( 206Pb/ 207Pb, 208Pb/ 207Pb) are reported for five 210Pb-dated Sphagnum peat profiles. The studied peat bogs are in the British Isles (Thorne Moors, England; Mull, Scotland; and Connemara, Eire) and central Europe (Ocean, northern Czech Republic; Rybarenska slat, southern Czech Republic). Both the U.K. and the Czech Republic experienced maximum Pb emissions from Ag-Pb smelting around 1880. Pb emissions from coal burning peaked in 1955 in the U.K. and in the 1980s in the Czech Republic. In both countries, use of alkyl-lead additives to gasoline resulted in large Pb emissions between 1950 and 2000. We hypothesized that peaks in Pb emissions from smelting, coal burning and gasoline burning, respectively, should be mirrored in the peat profiles. However, a more complicated pattern emerged. Maximum annual Pb accumulation rates occurred in 1870 at Ocean, 1940 at Thorne Moors, 1988 at Rybarenska slat, and 1990 at Mull and Connemara. Atmospheric Pb inputs decreased in the order Thorne Moors ≥ Ocean > Rybarenska slat > Mull > Connemara. The Ocean bog was unique in the central European region in that its maximum Pb pollution dated back to the 19th century and coincided with maximum Pb smelting at Freiberg and Pribram. In contrast, numerous previously studied sites showed no Pb accumulation maximum in the 19th century, but increasing pollution until the 1980s. It remains unclear why Ocean did not record the regional peak in Pb emissions caused by high coal and gasoline burning around 1980, while an array of nearby bogs studied previously did record the 1980 coal/gasoline peak, but no 1880 smelting peak. Mean 206Pb/ 207Pb ratios of potential pollution sources were 1.07 and 1.11 for gasoline, 1.17 and 1.17 for local ores, and 1.18 and 1.19 for coal in the U.K. and the Czech Republic, respectively. The calculated percentages of gasoline-derived Pb in peat (≤55% for the British Isles and ≤63% for the Czech Republic

  2. Estudio teórico y experimental sobre los morteros para muros resistentes de fábrica de ladrillo para la actualización de la Norma Básica MV 201-1972

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    Monterde Comba, Guillermo J.

    1984-12-01

    Full Text Available This theoretical and experimental study on cement or lime and cement mortars brings up to date the contents of Chapter 3: MORTARS, of Norm MV 201-1972 "Resistant brick-work walls" which lost its validity when disappeared portland cement P-250, substituted by portland cement PA-350 with active additions, prescribed in the new Standard RC-75 "Standard of general technical prescriptions for cements acceptance" being obligatory its fulfilment.

    El presente estudio teórico y experimental sobre morteros, de cemento o de cal y cemento, constituye la puesta al día del contenido del Capítulo 3º MORTEROS, de la Norma MV 201-1972 "Muros resistentes de fábrica de ladrillo'', que perdió su vigencia con la desaparición del cemento portland P-250, sustituido por el cemento portland PA-350 con adiciones activas prescrito en el nuevo Pliego RC-75 "Pliego de prescripciones técnicas generales para la recepción de cementos" de obligado cumplimiento.

  3. Resistencia química del hormigón. X.- Influencia de la adición de escoria a un cemento portland resistente al yeso. Estudio por DRX del sistema cemento 2/escoria-agua potable filtrada

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    Sagrera-Moreno, José Luis

    1981-06-01

    Full Text Available Not available

    En el presente trabajo [continuación de otro en el que se dio cuenta de las variaciones que experimentan las resistencias mecánicas a flexotracción y la evolución de los coeficientes de corrosión de probetas de mortero (1:3 conservadas bajo agua potable filtrada y agua de mar artificial ASTM D 1141-75] se estudia por DRX la composición estructural de las nuevas fases sólidas formadas en los medios de curado y de conservación (agua potable filtrada en donde han estado sumergidas las series testigo de probetas de mortero (1:3 de 1 X. 1 X 6 cm hechas con un cemento portland industrial resistente al yeso, cemento 2 < > P-450-Y, y con las mezclas de cemento 2/escoria granulada (vítrea = 85/ /15-65/35-40/60 y 30/70 (en peso, durante 21 días en el primer período y 56-90-180 y 360 días en el segundo, así como la evolución de las fases cristalinas de la fracción enriquecida (cemento hidratado extraída de uno de los prismas de cada serie de probetas de mortero.

  4. Successful therapeutic response of resistant cases of mucocutaneous leishmaniasis to a very low dose of antimony Resposta terapêutica bem sucedida de casos resistentes de leishmaniose mucocutânea a doses muito baixas de antimônio

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    Manoel Paes de Oliveira-Neto

    2006-08-01

    Full Text Available Two mucocutaneous leishmaniasis cases resistant to therapy are reported here. After the failure of initial therapies (antimony, amphotericin B and/or pentamidine patients received a low-dose schedule: one ampoule of meglumine antimoniate (405mg of pentavalent antimony [Sb v] by intramuscular injection, three times a week until complete healing of the lesions. One patient was cured with a total of 30 ampoules in 10 weeks and the other received 36 ampoules in 12 weeks. Both remain clinically cured after one year of follow-up.São relatados dois casos de leishmaniose mucocutânea resistentes ao tratamento. Depois das terapêuticas iniciais (antimônio, anfotericina B e/ou pentamidina, os pacientes receberam um esquema alternativo: uma ampola de antimoniato de meglumina (405mg de antimônio pentavalnte [Sb v] por via intramuscular, três vezes por semana até a cura completa das lesões. Um paciente recebeu um total de 30 ampolas durante 10 semanas e o outro, 36 ampolas durante 12 semanas. Ambos permanecem clinicamente curados até um ano após o tratamento.

  5. Competition effects with mixed stands of wheat and kochia (Kochia scoparia biotypes resistant and susceptible to acetolactase synthase inhibitor herbicides Efeitos competitivos da mistura de stands de trigo e biotipos de kochia (Kochia scoparia resistentes e susceptíveis aos herbicidas inibidores da acetolactase sintase

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    P.J. Christoffoleti

    1994-08-01

    Full Text Available Greenhouse experiments were conducted to compare the competitive ability of sulfonylurea resistant and susceptible kochia (Kochia scoparia L. Schard compared to wheat. The results of several replacement series experiments indicate that wheat was the dominant competitor, and an average of one wheat plant reduced resistant kochia yield per plant equal to the effect of 4.8 resistant kochia or 5.4 susceptible kochia plants. Intraspeciflc competition was more important than interspecific competition for wheat, whereas the reverse was true for the resistant and susceptible kochia. The results of the niche differentiation index (NDI indicate that wheat and either resistant or susceptible kochia are only partly limited by the same resources. The resistant and susceptible kochia, however, are limited by the same resources.Experimentos foram instalados em condições de casa-de-vegetação com o objetivo de comparar a capacidade competitiva de biotipos resistentes e suscetíveis aos herbicidas inibidores da enzima acetolactase synthase da planta daninha kochia (Kochia scoparia L. Schard comparada com trigo. Os resultados de diversos experimentos, utilizando a metodologia chamada de substitutiva, indicaram que o trigo foi o competidor dominante, e em média uma planta de trigo reduziu o crescimento da planta de kochia resistente igual ao efeito de 4,8 plantas de kochia resistente ou 5,4 plantas de kochia suscetível. A competição chamada de intraespecífíca foi mais importante que a competição interespecífica para o trigo, porém o inverso foi verdadeiro para os biotípos resistentes e susceptíveis de kochia. Os resultados do índice de diferenciação ecológica indicaram que trigo e qualquer um dos dois biotípos de kochia estudados foram limitados apenas parcialmente pelos mesmos recursos de crescimento. No entanto, o crescimento dos biotípos resistentes e susceptíveis de kochia foram limitados pelos mesmos fatores de crescimento.

  6. Late-Holocene hydroclimate and atmospheric circulation variability in southern Patagonia: insights from triple stable isotopes (δ18O, δ13C, δD) of peat bog Sphagnum moss

    Science.gov (United States)

    Xia, Z.; Yu, Z.; Zheng, Y.; Loisel, J.; Huang, Y.

    2017-12-01

    The Southern Hemisphere Westerly Winds (SHWWs) exert important influences on regional and global climates, but their long-term behaviors and dynamics are still poorly understood but critical for projecting future changes. Here we present a 5,500-year record from a Sphagnum-dominated peat bog located on the lee side of the Andes at 54.2 °S in southern Patagonia—based on plant macrofossils, Sphagnum cellulose δ18O and δ13C, and lipid δD data—to document and understand the variability in hydroclimate and atmospheric circulation. There is a striking negative correlation between cellulose δ18O and the Southern Annular Mode (SAM) index over the last millennium; particularly the 2.5‰ negative shift of δ18O is concurrent with the observed positive trend in the SAM over the recent decades. The interval of Medieval Climate Anomaly (MCA, 850-600 yr BP) is characterized by a 2.5‰ negative shift of δ18O and low δ13C values, while the Little Ice Age (LIA, 500-300 yr BP) is characterized by a 2.5‰ positive shift of δ18O and high δ13C values. Furthermore, we find the largest negative shift of δ18O ( 3‰) at 2,300 yr BP, suggesting a significantly positive shift in the SAM. We interpret high Sphagnum abundance and high cellulose δ13C values to reflect great moss moisture conditions, while cellulose δ18O variations primarily reflect moisture sources and atmospheric circulation. During the positive phase of SAM (e.g., the MCA and recent decades), strengthened SHWWs enhance the rain-shadow effect, resulting in dry climate and 18O-depleted precipitation (low δ18O values) in the study region. During the negative phase of SAM (e.g., the LIA), weakened SHWWs reduce rain-shadow effect, resulting in wet climate and high δ18O values caused by increases in moisture contributions from the southerly and easterly flows that do not experience strong Rayleigh distillation process during air mass transports. Furthermore, coupling cellulose δ18O and lipid δD enables

  7. Detection and enumeration of methanotrophs in acidic Sphagnum peat by 16S rRNA fluorescence in situ hybridization, including the use of newly developed oligonucleotide probes for Methylocella palustris.

    Science.gov (United States)

    Dedysh, S N; Derakshani, M; Liesack, W

    2001-10-01

    Two 16S rRNA-targeted oligonucleotide probes, Mcell-1026 and Mcell-181, were developed for specific detection of the acidophilic methanotroph Methylocella palustris using fluorescence in situ hybridization (FISH). The fluorescence signal of probe Mcell-181 was enhanced by its combined application with the oligonucleotide helper probe H158. Mcell-1026 and Mcell-181, as well as 16S rRNA oligonucleotide probes with reported group specificity for either type I methanotrophs (probes M-84 and M-705) or the Methylosinus/Methylocystis group of type II methanotrophs (probes MA-221 and M-450), were used in FISH to determine the abundance of distinct methanotroph groups in a Sphagnum peat sample of pH 4.2. M. palustris was enumerated at greater than 10(6) cells per g of peat (wet weight), while the detectable population size of type I methanotrophs was three orders of magnitude below the population level of M. palustris. The cell counts with probe MA-221 suggested that only 10(4) type II methanotrophs per g of peat (wet weight) were present, while the use of probe M-450 revealed more than 10(6) type II methanotroph cells per g of the same samples. This discrepancy was due to the fact that probe M-450 targets almost all currently known strains of Methylosinus and Methylocystis, whereas probe MA-221, originally described as group specific, does not detect a large proportion of Methylocystis strains. The total number of methanotrophic bacteria detected by FISH was 3.0 (+/-0.2) x 10(6) cells per g (wet weight) of peat. This was about 0.8% of the total bacterial cell number. Thus, our study clearly suggests that M. palustris and a defined population of Methylocystis spp. were the predominant methanotrophs detectable by FISH in an acidic Sphagnum peat bog.

  8. Dust is the dominant source of "heavy metals" to peat moss (Sphagnum fuscum) in the bogs of the Athabasca Bituminous Sands region of northern Alberta.

    Science.gov (United States)

    Shotyk, William; Bicalho, Beatriz; Cuss, Chad W; Duke, M John M; Noernberg, Tommy; Pelletier, Rick; Steinnes, Eiliv; Zaccone, Claudio

    2016-01-01

    Sphagnum fuscum was collected from twenty-five ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca Bituminous Sands (ABS) in northern Alberta (AB) in order to assess the extent of atmospheric contamination by trace elements. As a control, this moss species was also collected at a bog near Utikuma (UTK) in an undeveloped part of AB and 264km SW of the ABS region. For comparison, this moss was also collected in central AB, in the vicinity of the City of Edmonton which is approximately 500km to the south of the ABS region, from the Wagner Wetland which is 22km W of the City, from Seba Beach (ca. 90km W) and from Elk Island National Park (ca. 45km E). All of the moss samples were digested and trace elements concentrations determined using ICP-SMS at a commercial laboratory, with selected samples also analyzed using instrumental neutron activation analysis at the University of Alberta. The mosses from the ABS region yielded lower concentrations of Ag, As, Bi, Cd, Cu, Pb, Sb, Tl, and Zn compared to the moss from the Edmonton area. Concentrations of Ni and Mo in the mosses were comparable in these two regions, but V was more abundant in the ABS samples. Compared with the surface vegetation of eight peat cores collected in recent years from British Columbia, Ontario, Quebec and New Brunswick, the mean concentrations of Ag, As, Bi, Cd, Cu, Mo, Ni, Pb, Sb, Tl and Zn in the mosses from the ABS region are generally much lower. In fact, the concentrations of these trace elements in the samples from the ABS region are comparable to the corresponding values in forest moss from remote regions of central and northern Norway. Lithophile element concentrations (Ba, Be, Ga, Ge, Li, Sc, Th, Ti, Zr) explain most of the variation in trace metal concentrations in the moss samples. The mean concentrations of Th and Zr are greatest in the moss samples from the ABS region, reflecting dust inputs to the bogs from open pit mines, aggregate

  9. Padrão estomático de Capsicum ssp. resistentes e suscetíveis a Oidiopsis haplophylli Stomatal patterns of Capsicum genotypes resistant or susceptible to Oidiopsis haplophylli

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    Milton Luiz Paz Lima

    2010-03-01

    Full Text Available Visando relacionar a reação de Capsicum spp. resistentes e suscetíveis à Oidiopsis haplophylli com o padrão dos respectivos complexos estomáticos, foram analisados em dois ensaios, 5 e 15 genótipos de Capsicum spp. em delineamento inteiramente casualizado. Avaliou-se a abertura do ostíolo, a morfometria do estômato (comprimento, largura e área, o número de estômatos.mm-2 e a freqüência de estômatos (unidades de estômatos por células da epiderme nas superfícies adaxial e abaxial da epiderme foliar de plantas cultivadas em casa-de-vegetação. A variável abertura ostiolar não explicou a reação dos genótipos ao oídio, nem na face adaxial (R²=0,16 nem na abaxial (R²=0,13. Entretanto, o número de estômatos.mm-2 explicou a reação ao oídio em 84 % (face adaxial ou 74 % (face abaxial. Para a freqüência de estômatos, o modelo ajustou-se melhor na face adaxial (R² = 0,76, do que na face abaxial (R²=0,48. Maiores números e freqüências de estômatos em ambas as faces foliares ocorreram em pimentão 'Magali' (altamente suscetível, com valores significativamente maiores do que em 'HV-12' (altamente resistente. Sugere-se que a suscetibilidade de genótipos de Capsicum a O. haplophylli está parcialmente relacionada a mecanismos de defesa estruturais pré-formados, como o número e freqüência de estômatos, os quais se relacionam com o número de sítios de infecção. Por outro lado, para alguns genótipos, esta relação não foi significativa, indicando que outros mecanismos de resistência também estejam envolvidos.This work reports the reaction of Capsicum genotypes to the powdery mildew pathogen with variables of the stomatal complex, from samples of five to 15 Capsicum genotypes in a complete randomized experiments. Ostiolum size, stomatal morphometry (length, width and surface area, the number of stomata.mm-2, and the frequency of stomata (stomatal units per unit of epidermal cells were evaluated on both leaf

  10. Antimicrobial activity of surfactants produced by Bacillus subtilis R14 against multidrug-resistant bacteria Atividade antimicrobiana de surfactantes produzidos por Bacillus subtilis R14 frente a bacterias multidroga-resistentes

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    Paulo André Vicente Fernandes

    2007-12-01

    14, frente a bactérias multidroga-resistentes. Durante o cultivo em meio quimicamente definido, a tensão superficial do meio foi reduzida de 54 mN/m no início do crescimento microbiano para 30 mN/m depois de 20 h. Uma concentração de surfactante bruto de 2 g/L foi obtida depois de 40h de cultivo. Uma caracterização preliminar sugeriu que dois surfactantes foram produzidos. A avaliação antimicrobiana destes compostos foi realizada frente a vinte e nove bactérias. O perfil de multidroga-resistência foi previamente definido para Enterococcus faecalis (11 cepas Staphylococcus aureus (6 cepas, Pseudomonas aeruginosa (7 cepas e Escherichia coli IC18. Todas as cepas foram sensíveis aos surfactantes, em particular Enterococcus faecalis. Os resultados demonstraram que os lipopeptídios têm um amplo espectro de ação, incluindo microrganismos multidroga-resistentes.

  11. Competitiveness of ALS inhibitors resistant and susceptible biotypes of Greater Beggarticks (Bidens subalternans Competitividade de biótipos de Picão-Preto (Bidens subalternans Resistente e euscetível aos inibidores da ALS

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    F.P. Lamego

    2011-06-01

    Full Text Available The continuous use of ALS-inhibiting herbicides has led to the evolution of herbicide-resistant weeds worldwide. Greater beggarticks is one of the most troublesome weeds found in the soybean production system in Brazil. Recently, a greater beggarticks biotype that is resistant (R to ALS inhibitors due to Trp574Leu mutation in the ALS gene was identified. Also, the adaptive traits between susceptible (S and R to ALS inhibitors biotypes of greater beggarticks were compared. Specifically, we aimed to: (1 evaluate and compare the relative growth rates (RGR between the biotypes; (2 analyze the seed germination characteristics of R and S biotypes under different temperature conditions; and (3 evaluate their competitive ability in a replacement series study. The experiments were conducted at the University of Arkansas, USA, in 2007 and at Universidade Federal do Rio Grande do Sul (Federal University of Rio Grande do Sul, Brazil, in 2008. Plant proportions for replacement series studies were respectively 100:0, 75:25, 50:50, 25:75 and 0:100, with a total population of 150 plants m-2. There was no difference in RGR between R and S biotypes. The R-biotype germination rate was lower than that of the S biotype. However, at low temperature conditions (15 ºC, the reverse was observed. In general, there is no difference in the competitive ability between R and S greater beggarticks biotypes.O uso contínuo de herbicidas inibidores da ALS tem levado à evolução de plantas daninhas resistentes mundialmente. Picão-preto é uma das mais importantes plantas daninhas no sistema de produção de soja no Brasil. Recentemente, foi identificado um biótipo de picao-preto resistente (R aos inibidores da ALS devido à mutação Trp574Leu no gene ALS. Também, foram comparadas características adaptativas entre biótipos de picao-preto suscetível (S e R aos inibidores da ALS. Especificamente, os objetivos deste trabalho foram: (1 avaliar e comparar o crescimento

  12. Carriage of antibiotic-resistant pneumococci in a cohort of a daycare center Portadores nasofaríngeos de neumococo antibiótico-resistente en niños asistentes a guardería

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    Demóstenes Gómez-Barreto

    2002-01-01

    neumococo resistentes, determinar los serotipos y el perfil de sensibilidad a varios fármacos antimicrobianos. Material y métodos. Estudio prospectivo de una cohorte de niños de guardería, hecho de septiembre de 1997 a septiembre de 1999 entre 53 niños asistentes a la guardería del Hospital Infantil de México Federico Gómez, atendida por 20 empleados. Todos los participantes fueron seguidos en forma prospectiva, tomándose exudado nasofaríngeo cada cuatro meses. Los S. pneumoniae aislados se tipificaron y sometieron a pruebas de sensibilidad a diversos fármacos. Las razones de momios y la prueba exacta de Fisher o ji cuadrada se efectuaron a través de tablas de contingencia; se utilizaron intervalos de confianza a 95% para las razones de momios. Para el análisis se empleó el programa estadístico EPI INFO, versión 6.04 a. Resultados. S. pneumoniae se recuperó de 45/53 niños en una o más de las tomas. Se aisló un total de 178 cepas. El promedio de portador fue de 47%. Sólo siete adultos adquirieron un neumococo durante el estudio. Los tipos 6, 14, 19 y 23 representaron 77% del total. Se encontró elevada resistencia a la penicilina y eritromicina. Conclusiones. El estado de portador nasofaríngeo de S. pneumoniae, es un proceso dinámico. La colonización ocurre durante los primeros meses de vida y comprende solamente unos cuantos serotipos de neumococo. El estado portador disminuye conforme avanza la edad. Se encontró alta proporción de portadores con cepas resistentes de neumococo. Los niños que recibieron varios cursos de antimicrobianos, fueron los que mostraron mayor riesgo de presentar estado portador.

  13. Sobre puntos de la gramática particularmente resistentes al cambio: cuatro (largos siglos en la evolución de las relativas oblicuas de lugar. Un análisis variacionista

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    José Luis Blas Arroyo

    2017-05-01

    Full Text Available Mediante la utilización del paradigma variacionista y el empleo de un corpus integrado por textos de inmediatez comunicativa, mayoritariamente de carácter epistolar, en esta investigación se analiza un caso de la sintaxis particularmente resistente al cambio: la alternancia entre soluciones pronominales (que y, en menor medida, cual y adverbiales (donde en las relativas oblicuas locativas desde el siglo XVI hasta la primera mitad del XX. De los tres análisis de regresión independientes realizados, uno por cada periodo  (siglos XVI, XVIII y XX, se deriva un avance paulatino, aunque moderado, de las formas pronominales a lo largo de los siglos y la progresiva disminución del adverbio donde. Con todo, algunos factores lingüísticos se revelan especialmente persistentes en la explicación de la variabilidad (semántica, función sintáctica y categoría del antecedente, junto al priming estructural y la sintaxis de la cláusula regente, lo que dificulta la progresión del cambio. Con respecto a los factores extralingüísticos, la frecuencia de los relativos pronominales en los contextos comunicativos más distantes, así como su uso preferente por parte de las élites sociales y las generaciones adultas, muestra que estas formas se han adscrito a lo largo de la historia a los registros más formales y prestigiosos.

  14. Seleção de acessos de tomateiro resistentes à pinta-preta pela análise de agrupamento das curvas de progresso da doença

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    Bruno Soares Laurindo

    2015-02-01

    Full Text Available O objetivo deste trabalho foi selecionar acessos resistentes à pinta-preta (Alternaria tomatophila por meio da análise de agrupamento das curvas de progresso da doença em tomateiro (Solanum lycopersicum. Foram avaliados 134 acessos de tomateiro do Banco de Germoplasma de Hortaliças da Universidade Federal de Viçosa (BGH-UFV, no delineamento de blocos ao acaso, além das testemunhas suscetíveis 'Débora' e 'Santa Clara'. As plantas foram inoculadas com uma mistura de conídios de diferentes isolados de Alternaria spp. e avaliadas regularmente quanto à severidade da doença a cada três dias após a inoculação, no total de seis avaliações. Ajustou-se o modelo logístico aos dados de severidade da pinta-preta, e as estimativas obtidas para a incidência final da doença (B1 e a taxa de progresso da doença (B3 foram submetidas à análise de variância multivariada (Manova. As médias dessas estimativas, para cada acesso, foram submetidas à análise de agrupamento. Foram formados 24 grupos distintos com base no agrupamento das curvas de progresso da doença, o que possibilitou identificar os acessos BGH-2143, BGH-2235, BGH-2270 e BGH-2118 de tomateiro como potenciais fontes de resistência à pinta-preta.

  15. Identificação de biótipos de azevém (Lolium multiflorum resistentes ao herbicida glyphosate em pomares de maçã Identification of glyphosate-resistant ryegrass (Lolium multiflorum biotypes in apple orchards

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    L. Vargas

    2004-12-01

    Full Text Available O glyphosate é um herbicida de amplo espectro utilizado há mais de 15 anos em pomares de maçã na região de Vacaria-RS, para manejo da vegetação nas linhas da cultura. São realizadas, em geral, três a quatro aplicações por ciclo e a dose normalmente utilizada é de 720 a 1.080 g e.a. ha-1 de glyphosate (2 a 3 L ha-1 do produto comercial. O azevém (Lolium multiflorum é uma planta daninha comum em pomares e, tradicionalmente, sensível ao glyphosate. Entretanto, nos últimos anos a ocorrência de plantas de azevém que, após receberem o tratamento com glyphosate, não manifestam sintomas significativos de toxicidade sugere que elas adquiriram resistência ao produto. Assim, com o objetivo de avaliar a resposta de uma população de plantas de azevém ao glyphosate, foram realizados três experimentos: um em campo e dois em casa de vegetação. No experimento em campo os tratamentos avaliados constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880, 5.760 e 11.520 g e.a. ha-1, e os herbicidas paraquat, glufosinate, haloxyfop e diclofop foram empregados como produtos-padrão, aplicados em dois estádios vegetativos do azevém. No experimento em casa de vegetação, os tratamentos constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880 e 5.760 g e.a. ha-1 mais os herbicidas testemunhas, aplicados sobre plantas do biótipo considerado resistente e de um sensível. No segundo experimento realizado em casa de vegetação foram avaliados tratamentos contendo glyphosate (720, 1.440, 2.880, 720 + 720 e 720 + 1.440 g e.a. ha-1, em aplicações únicas e seqüenciais, mais os herbicidas paraquat, glufosinate, haloxyfop, clethodim, sethoxydim, diclofop, fenoxaprop, fluazifop, paraquat + diuron, atrazine + simazine, trifluralin e metolachlor. A toxicidade dos tratamentos herbicidas foi avaliada aos 15, 30 e 45 DAT (dias após tratamento. Os resultados obtidos nos experimentos em campo e em casa de vegetação, de forma

  16. Desempenho de populações híbridas F2 de arroz-vermelho (Oryza sativa) com arroz transgênico (O. sativa) resistente ao herbicida amonio-glufosinate Performance of F2 hybrid populations of red rice (Oryza sativa) with ammonium-glufosinate-resistant transgenic rice (O. sativa)

    OpenAIRE

    J.A. Noldin; S. Yokoyama; H. Stuker; F.T. Rampelotti; M.I.F. Gonçalves; D.S. Eberhardt; A. Abreu; P. Antunes; J. Vieira

    2004-01-01

    O arroz-vermelho e o arroz-preto constituem-se nas principais plantas daninhas infestantes da cultura de arroz irrigado, devido à dificuldade de controle seletivo desta espécie em lavouras comerciais. A utilização de cultivares geneticamente modificados resistentes a herbicidas não-seletivos constitui uma alternativa de controle do arroz-vermelho e arroz-preto em arroz irrigado. O objetivo deste trabalho foi avaliar o comportamento de populações híbridas F2 originárias do cruzamento entre o a...

  17. Influência da adição de diferentes fontes de fibras (farinha de trigo de grão inteiro e amido resistente) e de transglutaminase nas características tecnológicas, estruturais e sensoriais de massas alimentícias

    OpenAIRE

    Leandra Zafalon Jaekel

    2013-01-01

    Resumo: O interesse dos consumidores por alimentos com características funcionais tem aumentado nos últimos anos. A farinha de trigo de grão inteiro (FTGI) contém constituintes com efeitos benéficos a saúde (fibras, minerais, vitaminas, antioxidantes e aminoácidos). O amido resistente (AR) também tem sua contribuição à saúde, atuando como fibra alimentar. Massas alimentícias, cuja produção brasileira cresce a cada ano, constituem uma excelente forma de aplicação dessas matérias-primas. Contud...

  18. Costo efectividad del tratamiento de denervación renal vs. mejor tratamiento médico estándar disponible en el control de la hipertensión resistente en Colombia

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    Juan E. Valencia

    2014-06-01

    Full Text Available Objetivo: Mediante la adaptación a Colombia del modelo realizado por BresMed y previo análisis de transferibilidad, se realizó un análisis de costo-efectividad del tratamiento de denervación renal vs. mejor tratamiento estándar en el control de la hipertensión resistente y los eventos cardiovasculares relacionados. Métodos: Se construyó un modelo de Markov con 32 estados de salud y siete resultados finales: accidente cerebrovascular, infarto del miocardio, enfermedad coronaria, falla cardiaca, enfermedad renal crónica terminal, mortalidad cardiovascular y muerte. Se consideró un horizonte de toda la vida, la perspectiva desde el pagador y una tasa de descuento del 3%. Para el cálculo de las probabilidades de sufrir eventos se utilizaron las ecuaciones de riesgo de Framingham y las efectividades se tomaron del estudio clínico SYMPLICITY HTN-2. Los costos se extrajeron del entorno local y las tasas de mortalidad del Observatorio global de salud de la Organización Mundial de la Salud. Los resultados incluyeron los costos de cada alternativa de tratamiento, así como los años de vida ajustados a calidad ganados. Se realizaron análisis determinístico y probabilístico. Resultados: El tratamiento de denervación renal produjo 12,48 años de vida ajustados a calidad ganados a un costo de US $46.509 vs. 11,68 años de vida ajustados a calidad ganados del mejor tratamiento estándar a un costo de US $41.199, con un costo incremental por años de vida ajustados a calidad ganados de US $6.612. Tanto el análisis de sensibilidad univariado como el probabilístico, mostraron la robustez de los resultados. Conclusiones: El tratamiento de denervación renal, con un costo incremental por años de vida ajustados a calidad ganados de $6.612, muy por debajo de 1 PIB per cápita de Colombia, mostró ser altamente costo-efectivo.

  19. Avaliação da tolerância à vancomicina em 395 cepas hospitalares de Staphylococcus aureus resistentes à oxacilina Evaluation of the tolerance to vancomycin in 395 oxacillin-resistant Staphylococcus aureus strains isolated from Brazilian hospitals

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    Geraldo A. Oliveira

    2001-01-01

    Full Text Available O objetivo deste estudo foi avaliar a presença de tolerância à vancomicina em cepas de Staphylococcus aureus resistentes à oxacilina (Orsa isoladas de quatro hospitais da cidade de São Paulo. Foram estudadas 395 cepas Orsa isoladas de pacientes hospitalizados entre outubro de 1998 e maio de 2000. A determinação da concentração inibitória mínima (CIM e da concentração bactericida mínima (CBM para vancomicina foi realizada conforme padronizado pelo National Committee for Clinical Laboratory Standards (NCCLS. A tolerância à vancomicina foi definida como a razão CBM/CIM > ou = 32. Do total de cepas estudadas, 10,4% apresentaram CIM de 0,5µg/ml para vancomicina; 41,3%, CIM de 1µg/ml; 42,2%, CIM de 2µg/ml; e 6,1%, CIM de 4µg/ml. Em média, 49,1% dos Orsa apresentaram tolerância à vancomicina. Em conclusão, a tolerância à vancomicina entre as cepas Orsa foi considerada elevada. Conseqüentemente, aumentam as chances de falhas no tratamento com vancomicina, além de aumentar o risco da emergência de Staphylococcus aureus vancomicina-intermediário.The objective of this study was to evaluate the presence of tolerance to vancomycin in oxacillin-resistant Staphylococcus aureus (Orsa strains isolated from four hospitals in the city of São Paulo. From October/1998 to May/2000 we analysed 395 Orsa strains isolated from hospitalized patients. MIC and MBC to vancomycin were determined as standardised by National Committee for Clinical Laboratory Standards (NCCLS. Tolerance was defined as the ratio MBC/MIC > or = 32. The results showed that 10.4% of the Orsa strains presented a MIC of 0.5µg/mL for vancomycin, 41.3% presented a MIC of 1µg/mL, 42.2% a MIC of 2µg/mL and 6.1% a MIC of 4µg/mL. On average, 49,1% of the Orsa presented tolerance to vancomycin. We conclude that the tolerance to vancomycin amongst the Orsa strains was considered high. These high levels of tolerance augment the chances of failure in the treatment with

  20. Controle químico de biótipos de buva (Conyza canadensis e Conyza bonariensis resistentes ao glyphosate Chemical Control of glyphosate-resistant horseweed (Conyza Canadensis and hairy fleabane (Conyza bonariensis biotypes

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    Micheli Satomi Yamauti

    2010-09-01

    Full Text Available Estudos foram conduzidos na Estação Experimental de Citricultura de Bebedouro, SP para avaliar a resposta de biótipos de buva resistentes aos herbicidas glyphosate, bromacil + diuron, diuron e paraquat isolados e em mistura, e o efeito de uma aplicação seqüencial com glyphosate. O delineamento foi o de blocos casualizados com quatro repetições e sete tratamentos.. Os herbicidas foram aplicados com pulverizador costal, à pressão constante (mantido por CO2 comprimido, munido com barra com três bicos do tipo TT110015 com um consumo de calda equivalente a 150 L ha-1. O controle foi avaliado visualmente, através de escala percentual de notas. Para o controle geral das plantas daninhas os melhores resultados foram obtidos com diuron isolado e com glyphosate em mistura com bromacil + diuron, enquanto para o controle da buva não houve diferença entre os tratamentos. Depois da aplicação seqüencial, o melhor tratamento para o controle de buva foi com diuron e bromacil+diuron.Studies were conducted at Estação Experimental de Citricultura de Bebedouro, SP to evaluate the response of glyphosate-resistant horseweed and hairy fleabane biotypes to herbicides glyphosate, bromacil + diuron, diuron e paraquat isolated and in mixture and effect of a sequential application of glyphosate. The experimental design was of complete randomized blocks with four replication and seven treatments. The herbicides were applied with costal sprayer, constant pressure with three nozzles TT110015, the equivalent spray volume was 150 L ha-1. The control was visually evaluated, trough percentile note scale. The best results were obtained to general control of weed with diuron isolated and glyphosate in mixture with bromacil + diuron while to glyphosate-resistant horseweed and hairy fleabane there was no difference between the treatments. After sequential application to Conyza sp control, the best treatment was obtained associated with diuron and bromacil+diuron.

  1. Infecciones adquiridas en la comunidad por Staphylococcus aureus resistente a meticilina en un hospital de agudos Community-acquired methicillin-resistant Staphylococcus aureus infections in a hospital for acute diseases

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    S. Palombarani

    2007-09-01

    Full Text Available Staphylococcus aureus resistente a meticilina (SAMR es uno de los principales agentes asociados a infecciones intrahospitalarias; sin embargo, en los últimos años ha surgido como un patógeno emergente de la comunidad, causando infecciones graves, principalmente en jóvenes. Se describen 33 casos de infecciones por SAMR de origen comunitario, diagnosticadas entre mayo de 2005 y junio de 2006 en el HIGA "Eva Perón". Se estudiaron retrospectivamente los aislamientos; se confirmó la resistencia a meticilina mediante la detección del gen mecA, se investigó la presencia de genes que codifican dos factores de virulencia (leucocidina de Panton-Valentine -LPV- y g-hemolisina y el tipo de casete mec mediante PCR. Todos los pacientes se encontraban sanos previamente. Cuatro pacientes menores de 12 años presentaron bacteriemia, uno con neumonía grave y los 3 restantes con infección osteoarticular; todos los pacientes mayores de 12 años presentaron infecciones de piel y partes blandas sin compromiso sistémico. Se constató la presencia de casete mec tipo IV en todos los aislamientos; la resistencia a meticilina no se acompañó de resistencia a otros antimicrobianos; los aislamientos fueron portadores de genes que codifican para LPV y para g-hemolisina. Es importante considerar la presencia de estas cepas de origen comunitario a fin de elaborar estrategias para su correcto tratamiento.Methicillin- resistant Staphylococcus aureus (MRSA is one of the most prevalent pathogens associated with nosocomial infections. However, most recently, MRSA has arisen as an emerging community pathogen, causing serious infections, mainly among young patients. We herein describe 33 cases of infections caused by community-acquired MRSA (CMRSA, diagnosed between May 2005 and June 2006, at "Eva Perón" Hospital. The isolations were retrospectively studied. Methicillin resistance was confirmed by means of the detection of the mecA gene, and the genes for two virulence

  2. Inflamación Granulomatosa Crónica: Métodos de detección de bacilos ácido alcohol resistentes en biopsias embebidas en parafina

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    Javier Andres Bustamante Rengifo

    2010-05-01

    Full Text Available La detección de bacilos ácido alcohol resistentes (BAAR en frotis resulta un aporte significativo al diagnóstico y tratamiento de individuos con inflamación granulomatosa crónica (IGC. Con el objetivo de evaluar la presencia de BAAR en diferentes tejidos de pacientes con IGC demostrada y comparar la frecuencia de los extendidos positivos para BAAR con el grado de formación de granulomas y necrosis, se diseño un estudio retrospectivo, en el que se seleccionaron 57 bloques embebidos en parafina que contenían biopsias de pleura, pulmón, pericardio, ganglio linfático y lóbulo cerebral, correspondientes a 30 pacientes (63.3% hombres, mayores de 18 años, con IGC demostrada y remitidos al departamento de patología del Hospital Universitario del Valle entre el 2002-2008, a cada muestra se le realizaron 3 cortes y se sometieron a tinciones de H/E, Zielh Neelsen y Auramina. La detección de BAAR en frotis fue similar para ambas tinciones especiales en pacientes con IGC necrotizante, reflejando una excelente concordancia en el diagnostico (kappa=0.89, IC95%[0.68-1.0]. Sin embargo, la tinción con Auramina fue superior a la tinción Ziehl Neelsen para la detección de BAAR en pacientes con IGC no necrotizante (kappa=0.65, IC95%[0.23-1.0]. No se encontraron diferencias significativas entre la presencia de BAAR y el tipo de inflamacion, sexo y localización anatómica comprometida. En general, fue buena la concordancia entre los métodos histológicos empleados. Además, se hizo evidente la importancia de implementar el uso de técnicas moleculares mínimamente afectadas por el escaso número de bacilos presentes en las muestras, que finalmente ayudan en el reconocimiento del microorganismo.

  3. Root growth and lignification of glyphosate susceptible and resistant soybean at low temperaturesCrescimento e lignificação de raízes de soja convencional e resistente ao glifosato, em baixa temperatura

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    Patricia da Costa Zonetti

    2013-05-01

    Full Text Available Low temperature stress affects plant growth, including primary and secondary metabolism. Glyphosateresistant soybean contains a modified DNA, which encodes a different type of secondary metabolism enzyme related to lignin synthesis compared to conventional glyphosate-susceptible cultivars. Thus, this soybean cultivar might respond differently to low temperatures, compared to glyphosate-susceptible cultivars. This work aimed to investigate how decreasing temperatures influence the growth and lignin content of the glyphosate-resistant soybean compared to its susceptible parental cultivars. Three-day-old seedlings were cultivated in nutrient solution at 10, 15, 20, and 25°C (±2°C, using a 12-h photoperiod. After 96 h, taproot growth, fresh and dry biomass, and lignin levels were determined. The results indicate that lower temperatures decreased seedling and root growth in both types of cultivars; however, glyphosate-resistant soybean exhibited greater root length, biomass, and lignin content compared to the glyphosate-susceptible parental cultivar. O estresse causado pela baixa temperatura, dentre outras implicações, afeta o crescimento do vegetal assim como o seu metabolismo secundário. Pelo fato da soja RR apresentar variante enzimática de uma das principais vias do metabolismo secundário, ligada à síntese de lignina, pode apresentar comportamento diferenciado, sob baixa temperatura, se comparada com sua linhagem parental. O objetivo deste trabalho foi investigar possíveis diferenças no crescimento e nos conteúdos de lignina nas raízes de soja cultivar transgênica resistente ao glifosato e cultivar parental em resposta a redução de temperatura. Após três dias de germinação das sementes, as plântulas foram mantidas em solução nutritiva, a 10, 15, 20 e 25°C (±2°C, com fotoperíodo de 12 horas. Após 96 horas, foi avaliado o comprimento relativo da raiz primária, biomassa fresca e seca das raízes e os teores de lignina

  4. Ocorrência de linhagens de Pseudomonas aeruginosa cloro resistentes em águas de diferentes origens = Ocurrence of chlorine resistant strains of Pseudomonas aeruginosa from different water sources

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    Glícia Maria Torres Calazans

    2007-07-01

    Full Text Available Pseudomonas aeruginosa é conhecida por sua versatilidade metabólica e extrema capacidade de adaptação a diferentes ambientes, inclusive aquáticos. Para desinfecção de águas, o cloro e agentes que contêm cloro continuam sendo os mais usados no mundo. O objetivo deste trabalho foi avaliar a resistência ao cloro de linhagens de P. aeruginosa, isoladas de amostras de águas de diversos ambientes. Foram testados diferentes tempos de contato (1, 5, 10, 20, 30 e 40 minutos e soluções aquosas de cloro, com concentrações definidascom base na legislação vigente no país para água potável: 0,5; 1,0 e 2,0 ppm. O teste de resistência ao cloro foi desenvolvido por meio da exposição direta das bactérias às soluções. Os resultados revelaram que P. aeruginosa, isoladas de diferentes fontes de água, têm ahabilidade de sobreviver a diferentes concentrações de cloro. Na concentração de 1 ppm, a maioria das linhagens não foi inibida. As linhagens mais resistentes ao cloro também apresentaram relação de multirresistência à maioria dos antibióticos testados.The nutritional versatility and the adaptability of Pseudomonas aeruginosa to different environments, including water, are well known. Chlorine and other chlorine agents are used as water disinfecting all around the world. The aim of this work was to evaluate the possible chlorine resistance amongst P. aeruginosa strains isolated from different aquatic sources by using different contact time (1, 5, 10, 20, 30 and 40 minutes in solutions with known chlorine concentrations according current legislation in the country to potable water: 0.5; 1.0 and 2.0 ppm. The chlorine resistance test was done by direct exposure of P. aeruginosa under a solution with known chlorine concentration. Results showed that P. aeruginosa strains isolated from different aquatic sources are able tosurvive in different chlorine concentrations. At 1 ppm, most of them were not inhibited. It was also observed

  5. Staphylococcus aureus resistente a meticilina causante de infecciones comunitarias y de infecciones asociadas a la atención en salud en pacientes pediátricos del Hospital Universitario de Santander

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    Mayra Alejandra Machuca

    2014-04-01

    Full Text Available Introducción. Staphylococcus aureus resistente a la meticilina (SARM es un agente frecuente de infección en la población pediátrica. Aunque inicialmente las cepas de SARM estaban restringidas a los hospitales, se han reportado a nivel mundial brotes de infección por SARM en individuos sin factores de riesgo y, actualmente, SARM es una causa frecuente de infecciones hospitalarias y comunitarias. Objetivo. Describir la relación entre las características moleculares de aislamientos de SARM (casete cromosómico estafilocócico mec SCCmec y leucocidina Panton-Valentine y el origen de la infección y su presentación clínica en pacientes pediátricos del Hospital Universitario de Santander en Bucaramanga, Colombia. Materiales y métodos. Se incluyeron 43 aislamientos de SARM obtenidos de niños hospitalizados. La clasificación del SCCmec (I-V y la subclasificación del SCCmec-IV se realizaron en todos los aislamientos. Además, los genes de la leucocidina Panton-Valentine se detectaron mediante amplificación por PCR. Las características moleculares fueron asociadas con las características clínicas de cada paciente. Resultados. Entre los 43 SARM tipificados, el SCCmec-IVc fue el más frecuente con 77 %, seguido por el SCCmec-I con 16 % y el SCCmec-IVa con 2 %. Tres aislamientos no pudieron ser tipificados. Los genes de la leucocidina Panton Valentine se detectaron en 88 % de los SARM en aislamientos portadores del SCCmec-IVc/IVa y el SCCmec-I. Los SARM SCCmec-IV positivos para la leucocidina Panton-Valentine se asociaron con infecciones adquiridas en la comunidad (47 % y en el hospital (53 % con compromiso de piel y tejidos blandos, y en los casos más graves, con compromiso osteoarticular. Conclusiones. Estos resultados sugieren la presencia de cepas SARM-CO (SCCmec-IV positiva para PVL causantes de infecciones adquiridas en la comunidad y en el medio hospitalario en pacientes pediátricos en Colombia.

  6. Anatomopatologia e imunofluorescência direta e indireta das lesões de pênfigo foliáceo endêmico resistentes à corticoterapia Pathology, direct and indirect immunofluorescent test of lesions of pemphigus foliaceous resistent to corticotherapy

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    Vitor Manoel Silva dos Reis

    1991-04-01

    Full Text Available São estudados 16 doentes de pênfigo foliáceo endêmico (PFE, sob tratamento com corticosteróides, que ainda apresentavam lesões eritemato-pápulo-verrucosas, geralmente hiperpigmentadas, que foram caracterizadas como lesões resistentes à corticoterapia (LRC. O estudo destas lesões foi feito através de anatomopatologia e de imunofluorescência direta (IFD. Anatomopatologicamente essas lesões mostraram tendência à hiperplasia epitelial e clivagem em níveis variáveis na epiderme o que difere dos achados nas lesões recentes do PFE e coincide com os achados nas lesões crônicas do PFE da era pré-corticóide. A IFD da pele lesada foi positiva para IgG em 93,75% dos casos, como ocorre nas fases iniciais do PFE, tendo sido negativa no único caso em que não houve clivagem. Adicionalmente, em oito desses doentes, foram estudados a IFD da pele sã e a imunofluorescência indireta (IFI. A IFD foi positiva em três destes casos e a IFI foi negativa nos oito.A group of 16 patients with endemic pemphigus foliaceus under corticotherapy and still showing erythematous, papulous, verrucous, in general hyperpigmented lesions, which were characterized as cortico therapy resistant lesions, were studied. Such study was made through anatomopathology and direct immunofluorescence (DIF. Anatomopathologically, such lesions showed tendencies to epitelial hyperplasia and cleavage in variable levels at the epidermis what differs from the early lesions of EPF and coincides with the chronic injuries of the EPF of the pre-corticoid era. The DIF of the injured skin was positive for IgG in 93.75% of cases, as it happens in the early stages of EPF, being negative in a simple case in which there was not cleavage. In addition, in eight of those patients, the DIF of the healthy skin and the indirect immunofluorescence (IIF were studied. The DIF was positive in three of these cases and in all eight the IIF was negative.

  7. Cambios a lo largo del tiempo en la distribución de los complejos de clones dominantes de Staphylococcus aureus resistente a la meticilina en Medellín, Colombia

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    Ana M. Ocampo

    2014-04-01

    Full Text Available Introducción. Parte del éxito de Staphylococcus aureus resistente a la meticilina (SARM como patógeno se debe a la rápida diseminación de linajes pandémicos con perfiles variables de virulencia y sensibilidad antimicrobiana. En Colombia se han identificado clones asociados al hospital como el pediátrico (CC5-ST5-SCCmecIV, el brasilero (CC8-ST239-SCCmecIII y el chileno/cordobés (CC5-ST5-SCCmecI. Asimismo, se describió el USA300 (CC8-ST8-SCCmecIV, tradicionalmente asociado a la comunidad, causante de infecciones hospitalarias. Objetivo. Describir el comportamiento en el tiempo de los clones de SARM provenientes de un hospital universitario de Medellín en aislamientos recolectados con una década de diferencia. Materiales y métodos. Se analizaron 398 aislamientos de SARM, 67 recolectados en 1994 y 331 recolectados entre 2008 y 2010. La identificación y la sensibilidad a la meticilina se confirmaron mediante los genes nuc y mecA. La caracterización molecular incluyó la tipificación de spa, SCCmec, la electroforesis en gel de campo pulsado (Pulsed Field Gel Electrophoresis, PFGE, y la tipificación por secuenciación de locus múltiples (Multilocus Sequence Typing, MLST. Resultados. Al analizar los aislamientos de SARM de 1994 se encontró que pertenecían a un único linaje, el CC5-SCCmecIV, mientras que los aislamientos de 2008 a 2010 presentaron dos linajes dominantes: el CC8-SCCmecIVc, con cepas de los tipos spa t008 y t1610, estrechamente relacionadas con el clon USA 300, y el CC5-SCCmecI, con las de tipo spa t149, relacionadas con el clon chileno; no se detectaron cepas del linaje encontrado en 1994. Conclusiones. En este estudio se demuestra una dinámica en el tiempo de las cepas de S. aureus, y se señala la importancia de la vigilancia local y la difusión de los resultados, sobre todo en países como el nuestro, donde SARM es prevalente y la comprensión de su epidemiología es limitada.

  8. Resistencia química del hormigón. V.-Acción del agua de mar: Influencia de la adición de escoria a un cemento portland resistente al yeso. Evolución de las resistencias mecánicas a flexotracción y del coeficiente de corrosión

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    Gaspar-Tébar, Demetrio

    1980-09-01

    Full Text Available Not available

    En el presente trabajo (segundo de otro amplio en el que se estudia la influencia que ejercen diversas adiciones a tres cementos portland, desde un punto de vista de su comportamiento químico-resistente, frente a la acción de distintos medios potencialmente agresivos y que será objeto de otras publicaciones se da cuenta de la evolución que experimenta la resistencia química por el método de Koch-Steinegger y de las variaciones de las resistencias mecánicas a flexotracción de las probetas de mortero (1:3 de 1 X 1 X 6 cm hechas con un cemento portland industrial resistente al yeso (cemento 2 <> P-450-Y y con las mezclas cemento 2/escoria granulada (vítrea = 85/15 - 65/35 - 40/60 y 30/70 (en peso, sumergidas en agua potable filtrada, unas series de 12 probetas, y en agua de mar artificial (ASTM D 1141-75, otras series análogas, durante 56-90-180 y 360 días, después de haberlas curado 24 horas en un recinto saturado de humedad y hasta 21 días bajo agua potable filtrada.

  9. Contribución al estudio de la resistencia química de los cementos. Comportamiento mecánico de un cemento portland resistente al yeso (1.ª Parte

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    Gonzales-Vila, Victoriano

    1985-06-01

    Full Text Available This study, first part of a work where an account of the evolution of the mechanical resistances of various series of mortar and concrete tests submitted to the action of different agressive solutions will be given, sets up the chemical resistant behaviour of a sulphate resistant portland cement (with a content calculated —Bogue— null of C3A, of 10,8% of C4AF and of 81,7% of C3S + C2S against the CaSO4.2 H2O through the Le Chatelier-Anstett methods, and described in the ASTM C 452-73 and against the following agressive solutions: saturated solution calcium sulphate, Na2SO4 (2,1 g/l, MgSO4.7H2O (3,22 g/l, MgSO4.7 H2O (32,2 g/l, saturated of calcium sulphate + MgSO4.7H2O (3,22 g/l, saturated of calcium sulphate + MgSO4.7H2O (32,2g/l, Na2SO4 (3,5 g/l + NaCl (20,0 g/l, artificial sea water and, also, filtered drinking water, through of the Wittekindt and Kock Steinegger methods, during diverse periods, which allowed to establish a classification, according to his behaviour, of the studied cement against those agressive solutions.

    En el presente trabajo, primera parte de otro en el que se dará cuenta de la evolución de las resistencias mecánicas de diversas series de probetas de mortero y de hormigón sometidas a la acción de distintas disoluciones agresivas, se estudia el comportamiento químico-resistente de un cemento portland industrial resistente al yeso (con un contenido calculado, Bogue, nulo de C3A, del 10,8% de C4AFy del 81,7% de C3S + C2S frente al CaSO4.2 H2O por los métodos de Le Chatelier-Anstett y el descrito en la norma ASTM C 452-73 y frente a las siguientes disoluciones agresivas: disolución saturada de sulfato de calcio, de Na2SO4 (2

  10. Alta prevalência de crianças portadoras de Streptococcus pneumoniae resistentes à penicilina em creches públicas High prevalence of children colonized with penicillin-resistant Streptococcus pneumoniae in public day-care centers

    Directory of Open Access Journals (Sweden)

    Patrícia A. G. Velasquez

    2009-12-01

    Full Text Available OBJETIVOS: Investigar a prevalência de Streptococcus pneumoniae (pneumococos na nasofaringe de crianças sadias atendidas em creches municipais da cidade de Umuarama (PR. Avaliar a susceptibilidade aos antimicrobianos dos pneumococos isolados. MÉTODOS: Secreção da nasofaringe de 212 crianças foi coletada no período de abril a outubro de 2008. Após semeadura dos espécimes em ágar sangue e incubação a 37 °C por 24-48 horas, as colônias suspeitas de pertencerem a S. pneumoniae foram identificadas pela α-hemólise, sensibilidade à optoquina e bile solubilidade. A susceptibilidade à penicilina foi investigada pelos testes de disco-difusão e de diluição. A susceptibilidade aos demais antimicrobianos indicados no tratamento das infecções pneumocócicas foi realizada por disco-difusão RESULTADOS: A prevalência de pneumococos na nasofaringe foi de 43,4% (92/212, sendo maior em crianças com idade entre 2 e 5 anos (p = 0,0005. Não houve diferença significativa entre os sexos. Resistência intermediária e resistência plena à penicilina foram encontradas respectivamente em 34,8 (32/92 e 22,8% (21/92 dos isolados. Sessenta e sete amostras (72,8% foram resistentes ao sulfametoxazol-trimetoprim, oito (8,7% à eritromicina e seis (6,5% à tetraciclina. Uma amostra apresentou resistência à clindamicina (1,1%, e outra ao cloranfenicol (1,1%. Todas as amostras foram sensíveis a levofloxacina, ofloxacina, rifampicina, telitromicina, linezolide e vancomicina. Nove amostras foram consideradas multirresistentes, por apresentarem resistência a três ou mais classes de antimicrobianos. CONCLUSÕES: O presente estudo registrou uma alta prevalência de crianças portadoras sadias de amostras de S. pneumoniae resistentes à penicilina que podem constituir importantes reservatórios desse patógeno na comunidade.OBJECTIVES: To investigate the prevalence of Streptococcus pneumoniae (pneumococci in the nasopharynx of healthy children enrolled

  11. Profundidade de localização do herbicida imazetapir + imazapique no solo sobre a fitotoxicidade em de plantas de arroz não resistente Depth of placement of the herbicide imazethapyr + imazapic in soil profile on non-tolerant rice injury

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    Angela Da Cas Bundt

    2010-09-01

    Full Text Available Os herbicidas imazetapir e imazapique, usados em cultivares de arroz Clearfield®, possuem alta persistência e mobilidade no solo, ocasionando danos em genótipos de arroz não resistentes cultivados em rotação. Tais herbicidas podem lixiviar e atingir maiores profundidades ao longo do perfil. Esse posicionamento em profundidade pode ser um fator de seletividade e explicar parcialmente os diferentes resultados encontrados na literatura sobre o efeito residual do herbicida no solo. O objetivo do estudo foi avaliar o efeito da profundidade de localização no solo e da mistura formulada pelos herbicidas imazetapir e imazapique (75 e 25g e.a. L-1 na fitotoxicidade em genótipos de arroz não resistentes. Nesse sentido, foram conduzidos dois experimentos em solo com 15% de argila e 1,2% de matéria orgânica, em casa-de-vegetação, no campus da Universidade Federal de Pelotas (UFPel, em Pelotas, Rio Grande do Sul (RS. O experimento I consistiu de estudo preliminar visando a determinar a profundidade máxima de localização do herbicida no solo que causa danos ao arroz não resistente, e o herbicida foi alocado nas profundidades de 0, 5, 10, 20, 30, 50 e 70cm. O experimento II também consistiu na alocação do herbicida em profundidades ao longo do perfil do solo de 3, 6, 9, 12, 15 e 18cm. As variáveis analisadas foram fitotoxicidade, massa da matéria seca e estatura das plantas. O herbicida resultante da mistura formulada de imazetapir com imazapique localizado próximo à superfície do solo causa danos intensos em plantas de arroz não resistente, porém, quando alocado em profundidades maiores que 20cm da superfície do solo, não prejudica o desenvolvimento de genótipos de arroz não resistentes a essa mistura de herbicidas.The herbicides imazethapyr and imazapic, used in Clearfield® rice, have high mobility and persistence in the soil, causing injury to non-resistant rice grown in rotation. These herbicides can leach and reach greater

  12. Staphylococcus aureus resistente a la meticilina (SARM)

    Centers for Disease Control (CDC) Podcasts

    2007-10-22

    Datos importantes sobre las infecciones por SARM en Estados Unidos, en las escuelas y los entornos médicos. (Title: Methicillin-resistant Staphylococcus aureus (MRSA)Created: 10/2007).  Created: 10/22/2007 by National Center for Preparedness, Detection, and Control of Infectious Diseases.   Date Released: 11/9/2007.

  13. Fulminante, rituximab-resistente, mucocutane pemphigus vulgaris

    NARCIS (Netherlands)

    Gostyński, A.; Ammatuna, E.; Huls, G.; Wouthuyzen-Bakker, M.; Jonkman, M. F.; Horváth, B.

    2017-01-01

    Pemphigus vulgaris is an autoimmune disease mediated by auto-antibodies against desmoglein 1 and 3. First line treatment for pemphigus consists of systemic corticosteroids and anti-CD20 therapy (rituximab) to eliminate B-cells. Since 2005, more than 100 patients with pemphigus have been treated with

  14. Potencial de cruzamento natural entre o arroz transgênico resistente ao herbicida glufosinato de amônio e o arroz daninho Outcrossing potential of glufosinate-resistant rice to red rice

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    J.A. Noldin

    2002-08-01

    Full Text Available A utilização de cultivares de arroz irrigado resistentes a herbicidas não-seletivos, como o glufosinato de amônio, pode se constituir numa alternativa de controle de arroz daninho em lavouras de arroz irrigado. O objetivo deste trabalho foi avaliar a taxa e o sentido do cruzamento natural entre plantas de uma linhagem modificada geneticamente para resistência ao herbicida glufosinato de amônio (arroz GM e ao arroz daninho. A taxa de cruzamento natural entre o arroz GM como receptor feminino e o arroz daninho como doador de pólen foi de 0,22 e 0,02%, respectivamente para os ecótipos de arroz daninho com glumas de cor palha e com glumas pretas. No caso inverso, quando o arroz daninho foi o receptor feminino e o arroz GM o doador de pólen, a taxa de cruzamento foi de 0,26 e 0,14%, para o arroz daninho com glumas palha e com glumas pretas, respectivamente. Os resultados deste estudo evidenciaram que ocorreu cruzamento natural entre o arroz GM e o arroz daninho em percentuais que variaram de 0,14 e 0,48%, respectivamente para o arroz preto e para o arroz vermelho. A fim de minimizar a possibilidade de hibridação, medidas de controle eficientes devem ser adotadas no sentido de prevenir a coincidência de floração das plantas de arroz daninho com a das plantas de arroz GM cultivado.The broad spectrum non-selective herbicide ammonium glufosinate, combined with genetically modified glufosinate-resistant rice cultivars (GM rice, may comprise a rice weed control system for red rice and other weeds that infest Brazilian rice fields. The objective of this study was to evaluate the potential for outcrossing and gene flow of GM rice to red rice. Natural outcrossing between adjacent field plots (1 m x 1 m was measured during the 1999/2000 production season in Brazil. The outcrossing rate of the GM rice as the female parent to red rice, as the pollen donor, was 0.22% for strawhull and 0.02% for the blackhull red rice, respectively. In the reciprocal

  15. Durabilidad del hormigón: Acción del agua de mar sobre un cemento portland resistente a los sulfatos. Influencia de la adición de escorias y de cenizas volantes

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    Gaspar Tebar, Demetrio

    1991-12-01

    Full Text Available This article, is part of a long time ICCET investigation programs studies the variation of the mechanical resistance to flexotraction 1: 3 normalized mortar with 1 x 1 x6cm dimension, using sulphate-resistent portland cement mixed with 15-35-60 and 70% parts of a furnace slag, a fiy ash or silica sand. The samples were submitted to the action of AS.T.M. artificial sea water and filtered potable water during several time periods (3 years for the first and second addition and 1 year for the third after the cured period (1 day at 100% R.H. and 21 days inside filtered potable water. The evolution of the ionic concentration of the aggressive solutions were studied and also the new phases formed with its new structural composition. Finally, and account is given of the researches and first results about the behavior of the mortars and concretes made with two different industrial cements and submitted to the natural sea water at a selected area of the marine Huelva-Port.

    En este artículo, que forma parte de un Proyecto de Investigación del ICCETa largo plazo, se estudia la variación de las resistencias mecánicas —a flexotracción— de las probetas de mortero normalizado (1:3, de 1x1x6 cm, mezclando un cemento portland resistente a los sulfates y sus mezclas (cemento/adición = 85/15 - 65/35 - 40/60 y 30/70, en peso, con una escoria, ceniza volante y arena silícea. Se someten a la acción de agua del mar artificial ASTM y de agua potable filtrada durante diversos períodos de tiempo (hasta 3 años para las dos primeras adiciones, y hasta 1 año para la tercera después de la fase de curado (1 día en cámara húmeda y 21 días bajo agua potable filtrada. Se estudia la evolución de la concentración iónica de los medios en donde han estado sumergidas dichas probetas de mortero, las características químicas de las nuevas fases sólidas formadas y la composición estructural de estas nuevas fases sólidas. Por último, se da cuenta

  16. Manejo de Conyza bonariensis resistente ao glyphosate: coberturas de inverno e herbicidas em pré-semeadura da soja Management of glyphosate resistant Conyza bonariensis: winter cover crops and herbicides in soybean pre-seeding

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    F.P. Lamego

    2013-06-01

    Full Text Available Conyza bonariensis tornou-se a principal planta daninha da cultura da soja no Sul do Brasil, em decorrência da evolução para resistência ao herbicida glyphosate. O objetivo deste trabalho foi avaliar o efeito de diferentes coberturas de inverno e da associação de manejo de dessecação pré-semeadura da soja, visando ao controle de C. bonariensis resistente ao glyphosate. Um experimento foi conduzido em campo, na safra 2010/2011. Os tratamentos foram conduzidos em esquema de parcelas subdivididas, em que as coberturas de inverno foram alocadas nas parcelas principais: aveia-preta, nabo, ervilhaca, azevém, trigo e pousio. Nas subparcelas, foram alocados os tratamentos de manejo de dessecação pré-semeadura da soja: glyphosate (720 g e.a ha-1, glyphosate (720 g e.a ha-1 + 2,4-D (1.050 g e.a ha-1, glyphosate (720 g e.a ha-1 + 2,4-D (1.050 g e.a ha-1/paraquat (200 g i.a ha-1 + diuron (100 g i.a ha-1, glyphosate (720 g e.a ha-1 + chlorimuron-ethyl (80 g i.a ha-1, glyphosate (720 g e.a ha-1 + chlorimuron-ethyl (80 g i.a ha-1/paraquat (200 g i.a ha-1 + diuron (100 g i.a ha‑1 e roçada. O nabo foi a espécie de cobertura que produziu o maior volume de massa seca durante o inverno, enquanto a ervilhaca foi a que apresentou maior efeito supressor sobre a germinação e o desenvolvimento inicial de C. bonariensis. Associações de glyphosate com 2,4-D ou chlorimuron-ethyl, seguidas da aplicação sequencial de paraquat + diuron, causaram maior redução na infestação de C. bonariensis.Conyza bonariensis became the main weed in soybean crop in Southern Brazil, as a consequence of the evolution of resistance to the herbicide glyphosate. The objective of this work was to evaluate the effect of different winter cover crops and the association of burn-down herbicides on the control of glyphosate-resistant C. bonariensis. A field experiment was conducted in the 2010/2011 season. The treatments were arranged in a split-plot scheme, with the winter

  17. Seleção de famílias de feijoeiro resistente à antracnose e à mancha-angular Selection of common bean families resistant to anthracnose and angular leaf spot

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    Marcelo Geraldo de Morais Silva

    2006-10-01

    Full Text Available O objetivo deste trabalho foi identificar famílias de feijoeiro com resistência a Colletotrichum lindemuthianum e Phaeoisariopsis griseola e com outros fenótipos agronômicos desejáveis. As famílias utilizadas foram obtidas do cruzamento entre a linhagem H91, portadora de três alelos de resistência à antracnose, com três famílias F2:5 resistentes à mancha-angular, derivadas da cultivar Jalo EEP 558. Foi utilizado o delineamento látice quadrado em todos os experimentos. Inicialmente, foram avaliadas 144 famílias F2:3, no inverno de 2004, em Lavras, MG, com base no tipo de grão. Foram selecionadas 80 famílias F2:4 e avaliadas com a testemunha BRSMG Talismã, no período das águas de 2004/2005, no mesmo local. Considerando-se o tipo de grão e a resistência à mancha-angular e antracnose, foram mantidas 48 famílias F2:5, que foram avaliadas na seca de 2005, em Lavras e Lambari, MG. Essas 48 famílias passaram por inoculação das raças 2047, 73 e 1545 de C. lindemuthianum, para verificação da presença dos alelos de resistência Co-4², Co-5 e Co-7, respectivamente. Foram identificados genótipos da maioria das 48 famílias, quanto à reação à antracnose, das quais se destacaram quatro, em relação ao tipo de grão semelhante ao 'Carioca', de porte ereto, produtividade elevada e resistência à mancha-angular.The objective of this work was to select common bean families resistant to Colletotrichum lindemuthianum and Phaeoisariopsis griseola and, also, with superior agronomical traits. Families used were obtained from crosses of H91 lineage, bearer of three alleles resistant to anthracnose, and F2;5 families derived from the cultivar Jalo EEP 558, which is resistant to angular leaf spot. Square lattice design was used in all experiments. Initially the F2:3 families (144 were evaluated in the winter of 2004, in Lavras county, MG, Brazil, based on grain type. Eighty families (F2:4 were selected and evaluated with the check

  18. Híbridos pré-comerciais resistentes a Tuta absoluta obtidos de linhagem de tomateiro rica em acilaçúcares Pre-commercial hybrids obtained from an acylsugar-rich tomato inbred line, resistant to Tuta absoluta

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    Gabriel M Maciel

    2011-06-01

    Full Text Available O trabalho foi realizado com o objetivo de avaliar o potencial agronômico de híbridos de tomateiro a partir da linhagem TOM-687, rica em acilaçúcares e de resistência comprovada a pragas. O experimento foi instalado na HortiAgro, município de Ijaci, MG. Foi constituído de 30 genótipos (5 híbridos comerciais, 1 linhagem pré-comercial (TOM-687, e 24 híbridos nos quais TOM-687 foi utilizada como um dos pais, os quais foram conduzidos em tutoramento com haste dupla, no espaçamento de 1,30 x 0,50 m, totalizando 15.385 plantas por hectare. Foram realizadas nove colheitas, entre as datas de 01/11/08 a 28/11/08. Foram avaliadas as características de massa média por fruto (g fruto-1 e produção por hectare (t ha-1. Os 24 híbridos que tiveram TOM-687 como um dos pais apresentaram potencial produtivo similar ao das testemunhas comerciais Débora Max, Bravo, Bônus, Kombat e Atyna. Dos 24 híbridos experimentais, quatro (TEX-298, TEX-310, TEX-315 e TEX-316 foram avaliados quanto à resistência à traça-do-tomateiro (Tuta absoluta e mostraram-se mais resistentes do que as testemunhas comerciais.This experiment was designed to assess the agronomic potential of tomato hybrids obtained from the tomato line TOM-687, an acylsugar-rich line with confirmed resistance to an array of tomato pests. The experiment was carried out at the HortiAgro Sementes research station, in Ijaci, Minas Gerais State, Brazil. The treatments comprised 30 genotypes (5 commercial hybrid checks, 1 high acylsugar line (TOM-687, and 24 hybrids in which TOM-687 was one of the parents. Plants were trained to two stems, in a spacing of 1.30 m between rows x 0.50 m between plants within a row, totaling 15,385 plants per hectare. Nine harvests were performed between November 1st, 2008 and November 28th,2008. Traits assessed were mean fruit weight (g fruit-1 and total yield (t ha-1. All 24 hybrids with TOM-687 as a parent showed yields similar to those of the commercial check

  19. Frecuencia de portadores nasales de Staphylococcus aureus resistente a meticilina en personal de salud de hospitales de Nicaragua Frequency of nasal carriers of methicillin-resistant Staphylococcus aureus among health workers in Nicaraguan hospitals

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    Mercedes Cáceres

    2011-12-01

    Full Text Available OBJETIVO: Conocer la frecuencia de portadores nasales de cepas de Staphylococcus aureus resistentes a meticilina (SARM y el patrón de resistencia antimicrobiana de esas cepas obtenidas de trabajadores de la salud de cuatro hospitales de Nicaragua. MÉTODOS: Se realizó un estudio descriptivo, transversal, en el período del 1 de junio de 2009 al 30 de septiembre de 2010. Los hisopados nasales de los trabajadores de la salud que aceptaron voluntariamente participar en el estudio fueron cultivados en medio agar base de detección de resistencia a oxacilina (ORSAB. La identificación de los aislados de S. aureus se realizó por métodos cotidianos y la resistencia a meticilina se determinó por la presencia del gen mecA con la técnica de reacción en cadena de polimerasa. El patrón de resistencia antimicrobiana se detectó por difusión en disco. Cada participante firmó un consentimiento informado con anterioridad a la toma de la muestra. RESULTADOS: Participaron en el estudio 569 trabajadores de la salud, de los cuales 208 eran del hospital de León, 155 de dos hospitales de Chinandega y 206 del de Managua. La frecuencia de portadores nasales de SARM fue de 9,6% en León, 11,6% en Chinandega y 6,7% en Managua. El perfil de resistencia de las cepas SARM fue similar en los cuatro hospitales y todas las cepas fueron sensibles a vancomicina. Del total de cepas SARM aisladas, 15% fueron multirre-sistentes. El porcentaje de resistencia a eritromicina fue el más alto, seguido del de clindamicina. CONCLUSIONES: Los resultados del estudio se pueden considerar una advertencia sobre la circulación de cepas SARM entre el personal de salud de los hospitales participantes y aportan información relevante en relación al perfil de resistencia de las cepas SARM.OBJECTIVE: To determine the frequency of nasal carriers of strains of methicillin-resistant Staphylococcus aureus (MRSA and the antimicrobial resistance pattern of these strains, obtained from health

  20. Utilização do inseticida Methomyl na seleção de genótipos de aveia resistentes à helmintosporiose User of Methomyl insecticide for the selection of spot blotch resistant oat genotypes

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    Cristine Luise Handel

    1999-06-01

    Full Text Available A helmintosporiose é uma moléstia que afeta a cultura da aveia, reduzindo seu rendimento e qualidade de grão. A seleção de genótipos resistentes com utilização de filtrados tóxicos do fungo Helminthosporium sativum é eficaz, pois delimita a variabilidade do patógeno e reduz a interferência do ambiente na expressão do genótipo. Contudo, a obtenção dos filtrados tóxicos deste fungo é um processo lento e delicado. Dessa forma, a possibilidade do uso de substâncias sintéticas que simulem seu efeito, inibindo o transporte de elétrons da cadeia respiratória, é de grande interesse. O inseticida Methomyl é eficaz para simular o efeito da toxina do fungo que causa a helmintosporiose em milho, tendo o presente trabalho visado testar sua eficiência na cultura da aveia. Para isso, foi avaliado o crescimento de calos e raízes de aveia expostas ao Methomyl, quando crescimentos maiores indicaram maior resistência ao produto, e possível resistência à moléstia. Os resultados indicam que o Methomyl afeta o crescimento de raízes e calos de aveia e pode ser utilizado para separar os grupos de genótipos com e sem resistência à helmintosporiose. Assim, UFRGS 14, com maior sensibilidade aos filtrados tóxicos de H. sativum em outros estudos, também apresentou crescimento mais afetado pelo Methomyl em todos os experimentos aqui conduzidos.Spot Blotch is a plant disease which causes yield losses in oat and other cereals. Selection for resistant genotypes using Helminthosporium sativum toxic filtrates is an efficient technique, which reduces the pathogen variability and the influence of the environment over the genotype expression. The filtrates extraction is time consuming and a difficult process, and the possibility of using a synthetic product to simulate its action of inhibiting the cell electron transport chain would be useful. The Methomyl insecticide is an efficient product to simulate the effects of the fungus that causes spot

  1. Endocarditis due to vancomycin-resistant Enterococcus raffinosus successfully treated with linezolid: case report and review of literature Endocarditis por Enterococcus raffinosus resistente a vancomicina exitosamente tratada con linezolid: caso clínico y revisión de la literatura

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    A. Jasovich

    2008-12-01

    Full Text Available Enterococcus raffinosus is scarcely found in clinical samples and even less frequently as etiologic agent of endocarditis. We are herein presenting one case of mitral prosthetic-valve endocarditis in a 77-y-o male due to a vancomycinresistant Enterococcus raffinosus isolate, successfully treated with 6 weeks of linezolid, and a two-year follow up.Enterococcus raffinosus es una especie poco frecuente en materiales clínicos y menos aún como agente etiológico de endocarditis. En este trabajo se presenta un caso de endocarditis de válvula mitral protésica en un paciente de 77 años debida a Enterococcus raffinosus resistente a vancomicina y que fue exitosamente tratada con linezolid durante 6 semanas, con un seguimiento de 2 años.

  2. Potential use of Piper nigrum ethanol extract against pyrethroid-resistant Aedes aegypti larvae Utilização em potencial do extrato alcoólico de Piper nigrum como larvicida em Aedes aegypti resistente a piretróides

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    Naomi Kato Simas

    2007-08-01

    Full Text Available Fractionation of Piper nigrum ethanol extract, biomonitored by assays on pyrethroid-resistant Aedes aegypti larvae yielded isolation of the larvicidal amides piperolein-A and piperine. Comparing LC50 values, the ethanol extract (0. 98 ppm was the most toxic, followed by piperolein-A (1. 46ppm and piperine (1. 53ppm.O fracionamento do extrato etanólico de Piper nigrum biomonitorado por ensaios em larvas de Aedes aegypti resistentes a piretróides resultou no isolamento das amidas larvicidas piperoleína-A e piperina. Comparando-se os valores de CL50, o extrato etanólico (0. 98ppm foi o mais tóxico, seguido pela piperoleína-A (1. 46ppm e piperina (1. 53ppm.

  3. Crescimento de raízes de biótipos de capim-arroz resistente e suscetível ao quinclorac em competição Root growth of Echinochloa biotypes resistant and susceptible to quinclorac under competition

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    L.O.B. Schuch

    2008-01-01

    Full Text Available Objetivou-se com este trabalho avaliar o potencial competitivo de biótipos de capim-arroz resistente e suscetível ao quinclorac no ambiente do solo, como forma de inferir qual deles possui maior potencial de extração de recursos. O experimento foi instalado em casa de vegetação, constando de diferentes populações de plantas dos biótipos de capim-arroz resistente (R e suscetível (S ao herbicida quinclorac, oriundos da região arrozeira de Itajaí/SC. Foi estabelecida uma planta do biótipo de capim-arroz considerado como tratamento, no centro da unidade experimental; na periferia, foram semeadas dez sementes do biótipo oposto ao do tratamento central, sendo posteriormente estabelecido o número de plantas de acordo com o tratamento (0, 1, 2, 3, 4 ou 5 plantas. O delineamento experimental foi o completamente casualizado, em esquema fatorial 2 x 6, com quatro repetições. Aos 40 DAE, foram avaliados o comprimento, volume, massa fresca, massa seca e conteúdo de água das raízes das plantas. Os dados obtidos foram submetidos à análise de variância e, em caso de significância, efetuou-se o teste de Duncan, para avaliar o efeito do aumento na população de plantas, e o teste da Diferença Mínima Significativa (DMS, para avaliar diferenças entre biótipo resistente e suscetível, além da matriz de correlação. A imposição de competição no ambiente das raízes pode afetar mais o biótipo resistente ao quinclorac que o suscetível, sendo esta característica essencial para a sobrevivência do biótipo, principalmente sob escassez do recurso.The objective of this work was to evaluate the competitive potential of Echinochloa plants resistant and susceptible to quinclorac in the soil, to evaluate whether there are potential differences in extracting nutrients from the soil. The trial was carried out under greenhouse conditions. The treatments consisted of amounts of Echinochloa plants resistant or susceptible to quinclorac. At the

  4. Prevalence of mef and ermB genes in invasive pediatric erythromycin-resistant Streptococcus pneumoniae isolates from Argentina Prevalencia de los genes mef y ermB en aislamientos invasivos de Streptococcus pneumoniae resistentes a eritromicina recuperados de pacientes pediátricos en Argentina

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    A. Corso

    2009-03-01

    Full Text Available During the period 1993-2001, a total of 1,499 pneumococci isolates were recovered through the Argentinean surveillance of Streptococcus pneumoniae causing invasive disease in children under 6 years of age, 3.5% of which were erythromycin resistant. Among the 50 erythromycin-resistant strains available, 58% (n=29 harbored mefA/E genes (15 mefA, 30%; and 14 mefE, 28%, 34% (n=17 ermB, and 6% (n=3 both mefA/E plus ermB genes, while one isolate was negative for all the acquired genes studied. The England14-9 (42%, Poland6B-20 (20% and Spain9v-3 (16% clones were responsible for the emergence of pneumococcal macrolide resistance in pediatric population from Argentina.En el marco del programa de vigilancia regional SIREVA, se analizaron 1499 aislamientos de Streptococcus pneumoniae causantes de enfermedad invasiva en menores de 6 años, recuperados entre 1993 y 2001. Se detectó un 3,5% de resistencia a eritromicina. De los 50 aislamientos resistentes a eritromicina que pudieron ser estudiados, el 58% (n=29 tenían los genes mefA/E (15 mefA, 30% y 14 mefE, 28%, el 34% (n=17 el gen ermB y el 6% (n=3 la combinación de genes mefA/E y ermB. Sólo un aislamiento fue negativo para todos los genes analizados. Los clones internacionales England14-9, Poland6B-20 y Spain9v-3 representaron el 78% del total de aislamientos resistentes (42, 20 y 16%, respectivamente y se consideraron los responsables de la emergencia de la resistencia a macrólidos entre los neumococos que afectan a la población pediátrica de Argentina.

  5. Avaliação da sensibilidade a antimicrobianos de 87 amostras clínicas de enterococos resistentes à vancomicina Antimicrobial susceptibility testing of 87 clinical isolates of vancomycin-resistant enterococci

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    I.H. Saraiva

    1997-09-01

    Full Text Available OBJETIVOS. 1 Avaliar o padrão de sensibilidade in vitro de amostras clínicas de enterococos resistentes à vancomicina (ERV, aos antimicrobianos comumente utilizados no seu tratamento, bem como a antimicrobianos alternativos. 2 Avaliar a acurácia do E test, em comparação aos outros testes de sensibilidade a antimicrobianos (microdiluição em caldo e difusão em disco. MATERIAL E MÉTODOS. Foram analisadas 87 amostras clínicas de ERVs selecionadas de 1.936 isolados de enterococos coletados em 97 hospitais norte-americanos, no último trimestre de 1992. A identificação em nível de espécie foi feita pelos sistemas API 20S, Vitek e uma versão modificada do método convencional proposto por Facklam e Collins. A avaliação da sensibilidade in vitro aos antimicrobianos foi realizada pela técnica de microdiluição em caldo, E test e métodos de difusão em disco. As amostras foram testadas, tanto para antimicrobianos normalmente utilizados no tratamento de infecções enterocócicas (vancomicina, teicoplanina, ampicilina, penicilina, gentamicina e estreptomicina, como também para drogas alternativas potencialmente úteis (cloranfenicol, doxiciclina, esparfloxacina, ciprofloxacina, clinafloxacina, eritromicina, espectinomicina, trospectomicina, trimetoprim-sulfametoxazol e novobiocina. RESULTADOS. A avaliação dos testes de sensibilidade das 87 amostras de ERV revelou resistência, a ampicilina em torno de 86%, o mesmo sendo observado para penicilina. Em relação aos aminoglicosídeos, obtivemos alto grau de resistência, em torno de 82% e 85%, para gentamicina e estreptomicina, respectivamente. Apesar de pertencer à mesma classe da vancomicina, a teicoplanina foi ativa contra 29% das amostras de ERV. Entre os antimicrobianos alternativos testados, os que apresentaram maiores taxas de sensibilidade foram o cloranfenicol, a doxiciclina e a trospectomicina (82%, 92% e 94% de isolados suscetíveis, respectivamente. CONCLUSÃO. O

  6. Contribución al estudio de la resistencia química de los cementos. Comportamiento mecánico de un cemento portland resistente al yeso (2.ª parte

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    Gaspar-Tébar, Demetrio

    1985-12-01

    /serie/edad/disolución, hechas con un cemento portland industrial resistente al yeso (P-450-Y, según RC-75, sumergidas en agua potable filtrada y en las siguientes disoluciones agresivas: saturada de sulfato de calcio, de MgSO4.7 H2O (3,22 g/l, de MgSO42O (32,2 g/l, saturada de sulfato de calcio más MgSO4.7 H2O (3,22 g/l, saturada de sulfato de calcio más MgSO4.7 H2O (32,2 g/l y agua de mar artificial ASTM D 1141-75 durante 56 - 90- 180 - 360 - 540 - 720 - 900 y 1.080 días, después del período de curado (1 + 21 días. Así misino, se estudia la variación de dichas resistencias mecánicas a flexotracción y compresión de probetas de mortero (1 : 3 de 4 X 4 X 16 cm, a tracción centrifuga de probetas de mortero de 7 X 7 X 28 cm y a flexotracción y compresión de probetas de hormigón de 10 X 10 X 40 cm, hechas con el cemento mencionado (P-450-Y, cuando se sumergen en agua potable y en cinco disoluciones agresivas [disolución saturada de sulfato de calcio, disolución de Na2SO4 (2,1 g/l, disolución de MgSO4.7 H2O (3,22 g/l, disolución de Na2SO4 (3,5 g/l + NaCl (20,0 g/l y agua de mar artificial ASTM D 1141-75] durante 6 – 12 – 18 – 24 - 30 - 36- 42 – 48 - 54 y 60 meses, después del periodo de curado (1 + 30 días. Los resultados obtenidos han permitido establecer una graduación del cemento estudiado según su comportamiento, frente a las mencionadas disoluciones agresivas.

  7. Análise comparativa entre tuberculose multirresistente e tuberculose extensivamente resistente - Epidemiologia e factores preditivos Comparative analysis of multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis - Epidemiology and predictive factors

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    Ana Sofia Vilariça

    2008-12-01

    Full Text Available Introdução: A tuberculose extensivamente resistente (TBXDR define -se como uma forma de tuberculose multirresistente (TBMR com resistências adicionais às fluoroquinolonas e, pelo menos, a um dos antibacilares injectáveis seguintes: amicacina, canamicina e capreomicina. Foi classificada pela OMS como uma ameaça séria ao controlo da tuberculose, com consequências à escala mundial, assumindo os contornos de uma autêntica pandemia em algumas regiões do globo. Objectivo: Comparar os doentes com TBXDR versus outros perfis de TBMR no que diz respeito às características demográficas e epidemiológicas, factores etiopatogénicos e evolução no internamento. Material e métodos: Doentes internados no Serviço de Pneumologia III do Hospital de Pulido Valente no período compreendido entre Abril de 1999 e Junho de 2007, com o diagnóstico de TBMR microbiologicamente confirmado. Foram analisadas as seguintes variáveis: sexo, distribuição etária, raça, formas de apresentação da TB, grupos de tratamento, perfil de resistência aos antibacilares, estatuto de imigrante, número e duração de tratamentos anteriores, classificação OMS, co-infecção VIH, alcoolismo e/ou toxicodependência, demora média do internamento e mortalidade intra-hospitalar. A análise estatística realizou -se no programa SPSS (Statistical Package for the Social Sciences, versão 15.0. Nas variáveis categoriais, as diferenças estatísticas entre os grupos foram avaliadas através do teste qui -quadrado e as variáveis numéricas através do teste t. Para a construção do modelo preditivo da presença de TBXDR (variável dependente foi utilizada a análise de regressão logística, tendo sido incluídas as seguintes variáveis independentes: classificação OMS, coinfecção VIH, estatuto de imigrante, alcoolismo e/ou toxicodependência e número e duração de tratamentos anteriores. Resultados: Foram contabilizados 132 doentes com TBMR, dos quais 69 (52

  8. Características clínicas y sociodemográficas de los casos con tuberculosis resistente en el municipio de Armenia, Quindío (Colombia Clinical and socio-demographic characteristics of tuberculosis with antimicrobial resistance in Armenia, Quindio (Colombia

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    Nelson Enrique Arenas

    2012-09-01

    Full Text Available Objetivo: Analizar los factores sociodemográficos y clínicos de los pacientes con diagnóstico de tuberculosis resistente en el municipio de Armenia durante el período 2006-2009. Métodos: Se realizó un estudio descriptivo y retrospectivo con base en la notificación de pacientes con tuberculosis resistentes durante el período de estudio. Los datos fueron tomados de los registros consignados en las fichas de notificación y las tarjetas individuales de tratamiento categoría IV. Resultados: Entre 2006 y 2009, 678 pacientes ingresaron en el programa de control de la tuberculosis. De ellos, 14 casos (2,0% fueron resistentes al menos a un medicamento, y entre estos, 7 (50% fueron multirresistentes. El 21% estuvo asociado a infección por virus de la inmunodeficiencia humana. La tasa de fallecimientos en pacientes con tuberculosis con farmacorresistencia múltiple fue del 71%. Se encontró amplificación de la resistencia en 2 casos, quienes presentaron deterioro en el estado de salud y deceso. Conclusión: La situación en Armenia de resistencia a antituberculosos es de proporción similar a la del resto del país. Se encontraron factores de riesgo conocidos en los casos de resistencia (coinfección con virus de la inmunodeficiencia humana, farmacodependencia, abandono social en la mayoría de casos, pero también de resistencia primaria y sin factores de riesgo con farmacorresistencia múltiple y una alta mortalidad, lo que llama la atención para mejorar la vigilancia y el control de los casos en tratamiento en la ciudad.Objective: To analyze the socio-demographic and clinical diagnosis of patients with resistant tuberculosis in the municipality of Armenia in the period 2006-2009. Methods: We performed a retrospective descriptive study based on the notification of patients with resistant tuberculosis during the study period, data were taken from registrations under notification forms and individual treatment cards category IV. Results: 678

  9. Modificação da concentração de amido resistente em feijão macassar (Vigna unguiculata L. Walp por tratamento hidrotérmico e congelamento Modification of the concentration of resistant starch in macassar bean (Vigna unguiculata L. Walp hydrothermal process and freezing

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    Silvana Magalhães Salgado

    2005-06-01

    Full Text Available Considerando a importância das propriedades funcionais do amido resistente para a saúde, o elevado consumo de feijão macassar no Nordeste brasileiro e os efeitos do processo térmico e da estocagem sobre a estrutura do amido, foi realizado este trabalho com o objetivo de avaliar a influência de diferentes tratamentos hidrotérmicos (cocção sob pressão e sem pressão e do armazenamento a 20ºC por 15 e 30 dias, sobre a formação de amido resistente do feijão macassar em dois estádios de maturação (verde e seco. Para analisar os fatores combinados foi realizado um planejamento fatorial do tipo 2³ com três variáveis independentes (fatores e uma variável dependente (resposta. Todas as variáveis exerceram efeitos significativos na produção de AR e a maior formação foi registrada para o feijão seco devido à hidratação prévia a cocção sem pressão, além do tempo de armazenamento congelado de 30 dias. No que diz respeito às analises físicas, após os tratamentos hidrotérmicos, ocorreram transformações nos padrões de cristalinidade e no aspecto morfológico dos feijões.Considering the importance of the functional properties of resistant starch for health, the high consumption of the macassar bean in the northeast of Brazil and the effects of the thermal process and storage on the structure of the starch, this work was implemented to evaluate the influence of different hydrothermal treatments (cooking under pressure and whithout pressure and of storage at 20ºC for 15 and 30 days, on the formation of resistant starch in the macassar bean, in two stages of maturation (green and dryed. To analyse the combined factors, a factorial design type 2³ was realized with three independent variables (factors and one dependent variable (response. All the variables exercised significant effects on the production of the resistant starch and the highest formation was registered for the dried bean due to the previous hydration before

  10. Competição entre plantas de arroz e biótipos de capim-arroz (Echinochloa spp. resistente e suscetível ao quinclorac Competition between rice plants and Echinochloa spp. biotypes resistant or susceptible to quinclorac

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    L. Galon

    2009-01-01

    Full Text Available Objetivou-se com este trabalho avaliar a competitividade interespecífica de biótipos de capim-arroz resistente (R e suscetível (S ao herbicida quinclorac com a cultura do arroz irrigado. O experimento foi instalado em casa de vegetação e os tratamentos consistiram em manter uma planta de arroz cv. BRS Pelota no centro da unidade experimental, variando-se na periferia as densidades de capim-arroz em: 0, 1, 2, 3, 4 ou 5 plantas do biótipo R (ITJ-13 ou S (ITJ-17 oriundos da região de Itajaí-SC. O delineamento experimental utilizado foi o completamente casualizado, em esquema fatorial 2 x 6 com quatro repetições. Aos 40 dias após a emergência, foram avaliados as massas fresca e seca e o conteúdo de água de folhas, colmos e total da parte aérea do arroz e do capim-arroz. Houve efeito significativo dos tratamentos para todas as variáveis estudadas quando a cultura do arroz foi cultivada na presença de biótipos de capim-arroz R ou S. Esse efeito foi aditivo na proporção de 1 planta m-2. Entretanto, a capacidade competitiva dos biótipos de capim-arroz resistente e suscetível ao quinclorac, com as plantas de arroz, apresentou comportamento similar quando se variou a densidade de plantas por área.This work aimed to evaluate the interspecific competitiveness of Echinochloa spp. biotypes resistant or susceptible to the herbicide quinclorac. The trial was installed under greenhouse conditions, with the biotypes resistant (ITJ-13 and susceptible (ITJ-17 to quinclorac under competition with the rice plants. The treatments consisted of maintaining one rice plant at the center of the experimental unit, surrounded by 0, 1, 2, 3, 4 or 5 Echinochloa plants, according to the treatment. The trial was arranged in a completely randomized blocks design and factorial scheme 2 x 6, with four replications. Forty days after emergence, fresh dry weights and water content of the shoots were evaluated. There was a significant effect for all the variables

  11. Análisis clínico-epidemiológico de la portación intestinal de enterococos resistentes a vancomicina en una unidad de terapia intensiva Clinical and epidemiologic analysis of intestinal tract colonization with vancomycin-resistant enterococci in an intensive care unit

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    A.M. Togneri

    2005-03-01

    Full Text Available En un período de cinco meses y 25 días se investigó la portación intestinal de enterococos resistentes a vancomicina (EVR. Se estudiaron 124 pacientes (73% de 171 admitidos en la unidad de terapia intensiva (UTI, 35 de los cuales (28% resultaron ser portadores. Los aislamientos de EVR (n=35 fueron identificados como Enterococcus faecium (n=18, Enterococcus gallinarum (n=16 y Enterococcus raffinosus (n=1. Todos los aislamientos estudiados fueron resistentes a vancomicina (VAN (CIM90= 512 µg/ml y teicoplanina (CIM90= 32 µg/ml y portaban el gen vanA. Los estudios de tipificación molecular mostraron un alto grado de homología entre los aislamientos de E. faecium (un clon dominante y E. gallinarum (dos tipos clonales, sugiriendo su diseminación a modo de brote. No se encontraron diferencias significativas con la edad y el sexo de los pacientes no portadores (p>0,05, pero si con el tiempo de hospitalización y el uso de esquemas antibióticos de amplio espectro (pIntestinal tract colonization with vancomycin resistant enterococci (VRE was studied during five months and 25 days. Out of 171 patients hospitalized in the intensive care unit, 124 (73% were included in this study. Thirty five of them (28% were recognized as colonized with VRE. VRE isolates (n = 35 were identified as Enterococcus faecium (n=18, Enterococcus gallinarum (n=16, and Enterococcus raffinosus (n=1. All of them were resistant to vancomycin (MIC90= 512 µg/ml and to teicoplanin (MIC90= 32 µg/ml, having the vanA gene. By means of molecular methods a high homology was found among E. faecium and E. gallinarum isolates, respectively, suggesting their spread as a kind of outbreak. No significant differences in age or sex were found among colonized and non-colonized patients (p>0.05. On the other hand, the hospitalization time and the use of broad-spectrum antibiotics were associated with colonization. From this study we highlight the importance of enhancing all measures of

  12. Estudo comparativo entre métodos de coloração para a pesquisa do bacilo álcool-ácido resistente em secreções pulmonares A comparative study between two staining methods employed in the search of alcohol acid resistant bacilli in pulmonary secretions

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    Clara Pechmann Mendonça

    1975-03-01

    Full Text Available Apresentação do resultado comparativo entre dois métodos de coloração Osol e Ziehl-Neelsen para a pesquisa do bacilo álcool-ácido resistente, em 337 amostras secreção pulmonar. Foi realizada uma avaliação cultural de 287 amostras, mostrando que o método de Osol apresenta-se melhor nas baciloscopias discordantes e que há tendência em apresentar maior riqueza de germe.The comparative results obtained with the study of two staining methods, the Ziehl-Neelsen and the Osol ones, are presented. The study was performed with the alcohol acid resistant bacilli of 337 pulmonary secretion specimens. Evaluation cultures of 287 of these specimens were made. The Osol method proved to be better than the Ziehl-Neelsen one when dealing with discordant baciloscopic evidence. There tended to be a larger ammount of bacilli, too, when the former was used.

  13. Sphagnum growth and ecophysiology during mire succession

    Czech Academy of Sciences Publication Activity Database

    Laine, A. M.; Juurola, E.; Hájek, Tomáš; Tuittila, E. S.

    2011-01-01

    Roč. 167, č. 4 (2011), s. 1115-1125 ISSN 0029-8549 Institutional research plan: CEZ:AV0Z60050516 Keywords : photosynthesis * mire * successional Subject RIV: EF - Botanics Impact factor: 3.412, year: 2011

  14. On the ecology of a Sphagnum Bog

    NARCIS (Netherlands)

    Baas Becking, L.G.M.; Nicolai, E.

    1934-01-01

    For the ecologist systematic units are actors in a play. Whatever their christian- and family-names may be — it is their role, whether master or servant, whether villain or hero — which determines the character of the performance. This performance has, moreover, the property of being both continuous

  15. Caracterização morfológica e avaliação de cultivares de bananeira resistentes a Sigatoka Negra (Mycosphaerella fijiensis Morelet no sudoeste goiano Morphologic characterization and evaluation of banana cultivars resistant to the Black Sigatoka disease (Mycosphaerella fijiensis Morelet in the Southwest of the State of Goiás, Brazil

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    Silvia Correa Santos

    2006-12-01

    Full Text Available Cinco cultivares de bananeira resistentes a Sigatoka Negra foram cultivadas na área experimental da Universidade Federal de Goiás, no município de Jataí, localizado na região Sudoeste do Estado. O objetivo foi introduzir genótipos resistentes a Sigatoka Negra no Estado, bem como fazer a caracterização morfológica desses materiais nessas condições climáticas. O trabalho foi realizado por meio da avaliação, em três ciclos produtivos, dos seguintes componentes de produção: intervalo em dias entre o plantio e o florescimento, número de folhas no florescimento e na colheita, número de pencas por cacho, frutos por cacho e frutos por penca, comprimento do cacho e dos frutos e peso do engaço, das pencas e do cacho. As cultivares falsa FHIA-18 e Caipira produziram em média aos 393 dias, apresentando maior precocidade em relação às demais cultivares. Como era esperado, a FHIA-21, que é uma bananeira tipo Terra, apresentou um ciclo maior (488 dias. O clima e a altitude de Jataí-GO podem ter contribuído para o aumento do ciclo das cinco cultivares quando comparado com outras regiões. Para as características de produção, a FHIA-01 e a falsa FHIA-18 se destacaram das demais. Para o número de pencas, a Thap Maeo se destacou nos três ciclos, mostrando a característica deste genótipo. As maiores alturas na floração foram observadas nas cultivares FHIA-21 e Thap Maeo, que também foram as que mais sofreram com os efeitos do vento.Five banana cultivars resistant to the Black Sigatoka Disease were grown at the experimental field of the Universidade Federal de Goiás (UFG, located in the Southwest region of the State of Goiás (Brazil. This work aimed the introduction of Black Sigatoka resistant cultivars as well as the characterization of the morphological aspects of such cultivars at that climatic region. The following characteristics were evaluated, in the first three cycles: days between planting and flowering, leaf number at

  16. Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts Comportamento de promastigoteas metacíclicos de Leishmania major durante o curso da infecção e da resposta imune em hospedeiros resistentes versus suscetíveis

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    Regina Coeli Cunha Dórea

    2003-11-01

    Full Text Available Little is known on the epitopes derived from metacyclic promastigotes of Leishmania that are important on the regulation or destruction of the parasite, as targets of immune attack in the vertebrate host. In this study we investigated an alternative method to obtain metacyclic promasigotes of Leishmania major, as evaluated by the course of infection and delayed-type hipersensitivity (DTH in resistant versus susceptible inbred mice. Non-infective (procyclic promastigotes of L. major recently transformed from tissue amastigotes were attached to a negatively charged glass-wool column, whereas metacyclic promastigotes were not bound to columns and could be easily recovered. Optimal chromatography conditions were validated through statistical analyses. Parasite average yield from glass wool columns and promastigote viability were estimated by light microscopy. Metacyclic promastigotes yielded 43.5% to 57.5%. Different patterns of cutaneous lesions were obtained in BALB/c (susceptible and C57BL/6 (resistant mice, the former with highly infective lesions induced by metacyclic promastigotes. DTH responses proved to be higher in groups of C57BL/6 mice which were infected with metacyclic promastigotes. These results indicate that the new method could be integrated with the investigation of metacyclogenesis of Leishmania in vivo.Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro

  17. Prevalência da adesão ao tratamento anti-hipertensivo em hipertensos resistentes e validação de três métodos indiretos de avaliação da adesão Prevalence of anti-hypertensive treatment adherence in patients with resistant hypertension and validation of three indirect methods for assessing treatment adherence

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    Katia Vergetti Bloch

    2008-12-01

    Full Text Available O estudo estimou a adesão ao tratamento anti-hipertensivo farmacológico utilizando-se três métodos indiretos em uma coorte de hipertensos resistentes no Rio de Janeiro, Brasil, 2005. Os métodos foram: avaliação pelo paciente; avaliação do médico; teste de Morisky-Green (TMG adaptado para a língua portuguesa. Foi realizada validação preditiva comparando-se a diferença tanto de pressões de consultório como de monitorização de 24 horas (MAPA, em duas ocasiões, de pacientes com e sem adesão. As médias de pressões entre os grupos foram comparadas usando-se testes não-paramétricos. Foram entrevistados 200 pacientes com idade média de 63 anos (DP = 10,3, 73,5% do sexo feminino. A prevalência de adesão foi de 51% pelo TMG, 52% pelo médico e 80,5% pelo paciente. Ocorreram reduções das pressões arteriais de consultório e na MAPA dos pacientes com adesão por todos os métodos, mas não para os não-aderentes. O emprego de mais de um método para avaliação da adesão mostrou que indivíduos não-aderentes pelos três métodos (11,9% tiveram pior evolução dos níveis tensionais. Esse achado sugere que a hipertensão resistente não pode ser atribuída unicamente à baixa adesão.This study estimated adherence to anti-hypertensive medication using three indirect methods and their combinations in a cohort of patients with resistant hypertension in Rio de Janeiro, Brazil, 2005. The methods used were: self-reported adherence; physicians' adherence evaluation; and the Morisky-Green test (MGT translated into Portuguese. The predictive validation was performed comparing office blood pressure and ambulatory blood pressure monitoring, measured on two different occasions, from patients classified as adherent or not. The means were compared using non-parametric tests. Two hundred patients were interviewed. Mean age was 63 years (SD = 10.3, and 73.5% were female. Adherence prevalence was 51% using MGT, 52% according to the physician

  18. Identificação de híbridos de citros resistentes à mancha-marrom-de-alternária por meio de fAFLP e testes de patogenicidade Alternaria brown spot resistant citrus hybrid identification by means of fAFLP and pathogenicity tests

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    Edvan Alves Chagas

    2007-07-01

    Full Text Available O objetivo deste trabalho foi identificar híbridos, oriundos de hibridações controladas entre 'Folha Murcha' x 'Ponkan' e testá-los quanto à resistência a Alternaria alternata f. sp. citri. As plântulas foram obtidas via cultura in vitro de embriões. Utilizou-se o marcador molecular fAFLP para identificação dos híbridos e, em seguida, realizou-se o teste de patogenicidade nos híbridos com isolados de Alternaria alternata f. sp. citri, em condições de laboratório. Os pares de primers EcoRI AAG - MseI CAG e EcoRI ACC - MseI CAA foram os mais eficientes na identificação dos híbridos, os quais identificaram 48,5% de híbridos. Os híbridos F64, F108, F111, F113, F131 e F139 são potencialmente resistentes a Alternaria alternata f. sp. citri.The objective of this work was to identify hybrids obtained from controlled crossings between 'Folha Murcha' x 'Ponkan', and to check their resistance to Alternaria alternata f. sp. citri. The seedlings were obtained by in vitro embryo culture. The fAFLP marker technique was used to identify the hybrids, then laboratory pathogenicity test of the hybrids was accomplished with Alternaria alternata f. sp. citri isolates. The pairs of primers EcoRI AAG - Msel CAG and EcoRI ACC - Msel CAA were the most efficient for hybrids identification, and distinguished 48.5% of hybrids. Hybrids F64, F108, F111, F113, F131 and F139 showed potential resistance to the Alternaria alternata f. sp. citri.

  19. A case of familial transmission of community-acquired methicillin-resistant Staphylococcus aureus carrying the lnu(A gene in Santa Fe city, Argentina Caso de transmisión familiar de Staphylococcus aureus resistente a la meticilina adquirido en la comunidad portador del gen lnu(A en la ciudad de Santa Fe, Argentina

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    Emilce de los A Méndez

    2012-12-01

    Full Text Available Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA is increasingly recognized as an important pathogen causing skin and soft tissue infections as well as necrotizing pneumonia. We describe a case of familial transmission of CA-MRSA between a 6-month-old boy and his mother in Santa Fe City, Argentina. Both isolates showed an identical antimicrobial susceptibility profile, carried type IV SCCmec and harboured the pvl and the lnu(A genes. Isolates showed indistinguishable SmaI-PFGE patterns confirming their genetic relationship. These results corroborate the intrafamilial transmission of CA-MRSA and might associate this strain with the repetitive events of furunculosis within the family.Staphylococcus aureus resistente a la meticilina adquirido en la comunidad (SARM-AC es reconocido como un patógeno importante que causa infecciones de piel y partes blandas y neumonía necrotizante. Describimos un caso de transmisión familiar de SARM-AC entre un nino de 6 meses de edad y su madre en la ciudad de Santa Fe, Argentina. Ambos aislamientos mostraron idéntico perfil de sensibilidad a los antimicrobianos, tenían el SCCmec tipo IV, y contenían los genes pvl y lnu(A. Los aislamientos presentaron patrones de SmaI-PFGE indistinguibles entre sí, lo cual confirmó su relación genética. Estos resultados corroboran la transmisión intrafamiliar de SARM-AC; asimismo, este aislamiento podría asociarse con los eventos repetitivos de furunculosis en la familia.

  20. Detecção do gene mecA em estafilococos coagulase negativa resistentes à oxacilina isolados da saliva de profissionais da enfermagem Detection of mecA gene in oxacillin-resistant coagulase-negative staphylococci isolated from the saliva of nursing professionals

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    Juliana de Oliveira Rosa

    2009-08-01

    Full Text Available Estafilococos coagulase negativa estão frequentemente associados às infecções nosocomiais e os profissionais da saúde podem ser reservatório e dissemina-los no hospital e comunidade. O objetivo desse estudo foi identificar espécies de estafilococos coagulase negativa isolados da saliva de profissionais da enfermagem, determinar o perfil de resistência e detectar o gene mecA. Foram selecionados 100 estafilococos coagulase negativa, sendo 41 identificados como Staphylococcus epidermidis, 25 Staphylococcus saprophyticus, 18 Staphylococcus haemolyticus, 8 Staphylococcus cohnii, 4 Staphylococcus lugdunenses, 3 Staphylococcus capitis, e 1 Staphylococcus Simulans. Desses, 32% apresentaram resistência à oxacilina, 84,4% à mupirocina, 32% à cefoxitina, e todos sensíveis a vancomicina. Dos estafilococos coagulase negativa resistentes à oxacilina, 93,7% desenvolveram-se no agar oxacilina (6µg/ml e o gene mecA foi detectado em 75%. Os resultados sinalizam que maiores investimentos devem ser direcionados a identificação das espécies de estafilococos coagulase negativa nas instituições de saúde e na comunidade.Coagulase-negative staphylococci are frequently associated with nosocomial infections, and healthcare professionals can be reservoirs and spread them in hospitals and in the community. The aim of this study was to identify species of coagulase-negative staphylococci isolated from the saliva of nursing professionals, determine the resistance profile and detect the mecA gene. One hundred coagulase-negative staphylococci were selected: 41 were identified as Staphylococcus epidermidis, 25 as Staphylococcus saprophyticus, 18 as Staphylococcus haemolyticus, eight as Staphylococcus cohnii, four as Staphylococcus lugdunenses, three as Staphylococcus capitis and one as Staphylococcus simulans. Of these, 32% presented oxacillin resistance, 84.4% mupirocin resistance and 32% cefoxitin resistance, and all were vancomycin sensitive. Among the