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Sample records for crosta oceanica neoproterozoica

  1. Araxa Group in the type-area: A fragment of Neoproterozoic oceanic crust in the Brasilia Fold Belt; Grupo Araxa em sua area tipo: um fragmento de crosta oceanica Neoproterozoica na faixa de dobramentos Brasilia

    Energy Technology Data Exchange (ETDEWEB)

    Seer, Hildor Jose [Centro Federal de Educacao Tecnologica de Araxa, (CEFET), MG (Brazil); Brod, Jose Affonso; Fuck, Reinhardt Adolfo; Pimentel, Marcio Martins; Boaventura, Geraldo Resende; Dardenne, Marcel Auguste [Brasilia Univ., DF (Brazil). Inst. de Geociencias

    2001-09-01

    This study reviews the geological characteristics and puts forward a new evolution model for the Araxa Group in its type-area, the southern segment of the Neo proterozoic Brasilia Belt, Minas Gerais, Brazil. The Araxa Group is confined within a thrust sheet belonging to a syn formal regional fold, the Araxa Syn form, overlying two other thrust sheets made of the Ibia and Canastra Groups. The Araxa Group is described as a tectono stratigraphic terrane in the sense of Howell (1993). It comprises an igneous mafic sequence, with fine and coarse grained amphibolites, associated with pelitic meta sedimentary rocks, and subordinate psanmites. All rocks were metamorphosed to amphibolite facies at ca. 630 Ma ago and were intruded by collisional granites. The amphibolites represent original basaltic and gabbroic rocks, with minor ultramafic (serpentinite/ amphibole-talc schist). The basalts are similar to high Fe O tholeiites, with REE signatures that resemble E-MORB and {epsilon}{sub Nd(T)} =+ 1.1. The meta sedimentary rocks are interpreted as the result of a marine deep-water sedimentation. They have Sm-Nd model ages of 1,9 Ga, and {epsilon}{sub Nd(T)} = -10.21. The amphibolites and metasediments could represent a fragment of back-arc oceanic crust. The data presented here differ significantly from the original definition of Barbosa et al. (1970) who describe the Araxa Group as a pelitic/psanmitic sequence and the collisional granites as a basement complex. (author)

  2. Posidonia oceanica

    Science.gov (United States)

    Coletti, Alessia; Valerio, Antonio; Vismara, Elena

    2013-05-15

    High-grade cellulose (97% α-cellulose content) of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H₂O₂ and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C . Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS) of 0.72 was produced by quenching Fenton's reagent (H₂O₂/FeSO₄) generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p -nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

  3. SUITABLE MORDANTS FOR DYEING POSIDONIA OCEANICA FIBERS

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    ROMÁN Silvia

    2017-05-01

    Full Text Available Posidonia oceanica is the most extended sea grass in the Mediterranean Sea. Important quantities of this alga are accumulated on coasts making necessary the cleaninness of those beaches where it can be found. For this reason, many authors are developmenting new products made by this raw material, like green composites or are studing this material to be used as biomass, for example. The aim of this study is to dye the Posidonia Oceanica fiber using commercial natural dye to change their appearance to get a material more attractive for different areas. To achieve this aim, fibers were scoured and bleached in order to remove the brown colour of the Posidonia Oceanica fibers. Scoured and bleached processes were followed by the treatment done for cellulosic fibers, because some researches indicate that P. Oceanica is composed of high quantity of cellulose. Different types of biomordants were use in the pre-treatment of the fiber to improve the affinity between the fiber and the dye used. To compare the results, we evaluate the colour of each sample using CIELAB parameters and colour differences (ΔE*, which are obtained by reflexion spectrophotometre. The results showed that medium molecular weight chitosan, which was used as biomordant, gets the highest intensity of colour

  4. Crostas biológicas em saprolitos de gnaisse: ciclagem biogeoquímica, micromorfologia e ensaio de colonização

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    E. S. Trindade

    2001-12-01

    Full Text Available O papel biogeoquímico e estrutural das crostas microbióticas é praticamente desconhecido, embora estas sejam freqüentes na superfície de taludes naturais e antrópicos expostos em domínio tropical úmido. O presente trabalho teve como objetivo estudar as interações envolvidas no intemperismo biogeoquímico decorrente da ação de microrganismos e plantas inferiores na superfície de saprolitos gnáissicos expostos em taludes da Zona da Mata de Minas Gerais. Foram investigados também os efeitos das associações organominerais na formação e estabilização estrutural de agregados, bem como as feições micropedológicas das diferentes crostas e do substrato sob influência destas. Fez-se o isolamento de cianobactérias, objetivando uma visão preliminar da viabilidade de obtenção de inóculo em laboratório, para posterior utilização na estabilização de superfícies minerais expostas. O grau de intemperismo e o caráter máfico ou félsico dos substratos foram determinantes no comportamento dos organismos em relação à ciclagem biogeoquímica, influenciando os valores de pH, a atividade de argila e o caráter eutrófico ou distrófico das crostas e saprolitos. Em geral, observou-se concentração de K e Al trocáveis na crosta, sendo K o elemento mais consistentemente associado à ciclagem biogeoquímica. O mesmo ocorreu em relação a Ca e Mg trocáveis, exceto nos saprolitos mais máficos, onde sua abundância mascarou a ciclagem biogeoquímica. As crostas tenderam também a concentrar P, Mn, Pb e Ni disponíveis, em todos os pontos, embora a contribuição de poluentes atmosféricos, no caso de Pb, possa estar mascarando os efeitos da atividade microbiana na mobilidade deste elemento. Os teores de N disponíveis foram elevados, em decorrência do N fixado pelas cianobactérias. Os valores de Fe-ditionito, juntamente com os resultados das observações micropedológicas, mostraram um modelo de oxidação por influ

  5. Resistência hidráulica da crosta formada em solos submetidos a chuvas simuladas Crust hydraulic resistance in soils under simulated rain

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    Viviane dos Santos Brandão

    2006-02-01

    Full Text Available Para avaliar a redução da taxa de infiltração em solos sujeitos ao encrostamento decorrente da aplicação de chuvas simuladas, foi realizado um experimento em esquema fatorial 5 x 6, sendo cinco solos (Argissolo Vermelho, Argissolo Vermelho-Amarelo, Latossolo Vermelho-Amarelo, Neossolo Flúvico e Neossolo Quartzarênico e seis energias cinéticas de chuva (0, 525, 1051, 2102, 3153 e 4204 J m-2, com três repetições. A partir dos dados de taxa de infiltração da água no solo e da espessura da crosta, determinadas por micromorfometria, calcularam-se a condutividade e a resistência hidráulica da crosta. Todos os solos apresentaram redução da taxa de infiltração, quando a energia cinética de chuva simulada aplicada aumentou. A resistência hidráulica da crosta aumentou com a energia cinética (especialmente para os solos Argissolos Vermelho-Amarelos e Vermelho até atingir um valor máximo, a partir do qual ocorreu diminuição, atribuída ao desgaste erosivo da crosta provocado pelo aumento do escoamento superficial, associado aos maiores valores de energia cinética da chuva simulada. Por meio de análise de regressão múltipla, foram determinadas a relação da resistência hidráulica da crosta com a energia cinética da chuva e as características químicas e físicas de cada solo. A variável resistência hidráulica da crosta mostrou-se adequada a ser utilizada nos modelos infiltração da água no solo para descrever a influência do encrostamento neste processo.To evaluate the decrease in infiltration rate in crusting soils an experiment was carried out using a rainfall simulator. Treatments were distributed in a factorial schedule 5 x 6, using five soils (Red Ultisol, Red-Yellow Ultisol, Red-Yellow Oxisol, Fluvic Entisol and Arenic Entisol and six rainfall kinetic energies (0, 525, 1051, 2102, 3153, and 4204 J m-2 with three replications. According to the water infiltration rate and crust thickness, as determined by

  6. Nitrogen-fixing bacteria in Mediterranean seagrass (Posidonia oceanica) roots

    KAUST Repository

    Garcias Bonet, Neus

    2016-03-09

    Biological nitrogen fixation by diazotrophic bacteria in seagrass rhizosphere and leaf epiphytic community is an important source of nitrogen required for plant growth. However, the presence of endophytic diazotrophs remains unclear in seagrass tissues. Here, we assess the presence, diversity and taxonomy of nitrogen-fixing bacteria within surface-sterilized roots of Posidonia oceanica. Moreover, we analyze the nitrogen isotopic signature of seagrass tissues in order to notice atmospheric nitrogen fixation. We detected nitrogen-fixing bacteria by nifH gene amplification in 13 out of the 78 roots sampled, corresponding to 9 locations out of 26 meadows. We detected two different types of bacterial nifH sequences associated with P. oceanica roots, which were closely related to sequences previously isolated from the rhizosphere of a salt marsh cord grass and a putative anaerobe. Nitrogen content of seagrass tissues showed low isotopic signatures in all the sampled meadows, pointing out the atmospheric origin of the assimilated nitrogen by seagrasses. However, this was not related with the presence of endophytic nitrogen fixers, suggesting the nitrogen fixation occurring in rhizosphere and in the epiphytic community could be an important source of nitrogen for P. oceanica. The low diversity of nitrogen-fixing bacteria reported here suggests species-specific relationships between diazotrophs and P. oceanica, revealing possible symbiotic interactions that could play a major role in nitrogen acquisition by seagrasses in oligotrophic environments where they form lush meadows.

  7. Early colonization on Artificial Seagrass Units and on Posidonia oceanica (L.) Delile leaves

    OpenAIRE

    Pete, Dorothée; Lepoint, Gilles; Bouquegneau, Jean-Marie; Gobert, Sylvie

    2015-01-01

    Many epiphytes grow on Posidonia oceanica (L.) Delile leaves but early stages of that colonization are not well known. To study this early colonization without destroying the plant, Artificial Seagrass Units (ASUs) were utilised. The first nine days of colonization by macroscopic eukaryotic organisms on natural P. oceanica leaves and on ASUs were studied. The capability of those ASUs to mimic P. oceanica in the long term was also evaluated. Indeed, early colonists of a substrate can influe...

  8. Endophytic bacterial community of a Mediterranean marine angiosperm (Posidonia oceanica

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    Neus eGarcias-Bonet

    2012-09-01

    Full Text Available Bacterial endophytes are crucial for the survival of many terrestrial plants, but little is known about the presence and importance of bacterial endophytes of marine plants. We conducted a survey of the endophytic bacterial community of the long-living Mediterranean marine angiosperm Posidonia oceanica in surface-sterilized tissues (roots, rhizomes and leaves by DGGE. A total of 26 Posidonia oceanica meadows around the Balearic Islands were sampled, and the band patterns obtained for each meadow were compared for the three sampled tissues. Endophytic bacterial sequences were detected in most of the samples analyzed. A total of 34 OTUs (Operational Taxonomic Units were detected. The main OTUs of endophytic bacteria present in P. oceanica tissues belonged primarily to Proteobacteria (α, γ and δ subclasses and Bacteroidetes. The OTUs found in roots significantly differed from those of rhizomes and leaves. Moreover, some OTUs were found to be associated to each type of tissue. Bipartite network analysis revealed differences in the bacterial endophyte communities present on different islands. The results of this study provide a pioneering step toward the characterization of the endophytic bacterial community associated with tissues of a marine angiosperm and reveal the presence of bacterial endophytes that differed among locations and tissue types.

  9. In vivo localization studies in the stramenopile alga Nannochloropsis oceanica.

    Science.gov (United States)

    Moog, Daniel; Stork, Simone; Reislöhner, Sven; Grosche, Christopher; Maier, Uwe-G

    2015-02-01

    The tiny eustigmatophyte Nannochloropsis sp. recently emerged as a promising model organism for biotechnology as it possesses a considerably high cellular oil content interesting for biodiesel production. Furthermore, the alga was shown to be genetically well accessible providing powerful tools for biotechnological engineering as well as basic research. Nannochloropsis sp. can be transformed very efficiently taking advantage of homologous recombination, however, so far it remained unclear whether these organisms are also suitable model systems for in vivo protein localization studies due to their small cell size. Here we present, to our knowledge, the first protein localization studies based on the expression of chimeric fluorescent fusion proteins in the genus Nannochloropsis using N. oceanica CCMP1779 as a model organism. Besides expressing a cytosolic green fluorescent protein (GFP), the reporter could be directed into subcellular structures such as the mitochondria, the endoplasmic reticulum and secretory pathway as well as the complex plastid including the periplastidal compartment and the stroma via fusion of specific N-terminal targeting sequences. These results expand the potential of N. oceanica as a model system in biotechnology as well as cellular biology for which now an almost complete molecular tool set exists. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. Metal pollution determined by pollution indices for sea grass P. oceanica and surface sediments

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    Stanković Slavka

    2015-01-01

    Full Text Available Concentrations of Fe, Mn, Cu, Zn, Pb, Ni, Co, As, Co, and Hg in the sea grass Posidonia oceanica and surface sediment samples were determined. Together with P. oceanica, surface sediment samples were collected at eight locations in the major demographic, tourist and port areas along the Montenegrin coast to assess metal pollution. The metal pollution index (MPI and metal enrichment factor (EF were calculated and used to evaluate the impact of heavy metals in the surface sediment on P. oceanica. The sediment MPI and EF values were lower than these values in P. oceanica at the same locations. Since the surface sediment contained lower mean concentrations of Zn, Ni, Pb, Cd and Hg, than the sea grass P. oceanic, we concluded that the sea grass absorbed some metals from the seawater column. [Projekat Ministarstva nauke Republike Srbije, br. III 43009

  11. Reduced carbon sequestration in a Mediterranean seagrass (Posidonia oceanica) ecosystem impacted by fish farming

    DEFF Research Database (Denmark)

    Apostolaki, E; Holmer, Marianne; Marbà, N

    2011-01-01

    We studied the relationship between sediment nutrient enrichment and carbon sequestration, using the ratio of gross primary production to respiration (P/R), in a fish-farming impacted and an unaffected Mediterranean seagrass (Posidonia oceanica) ecosystem in the Aegean Sea, Greece. Carbon (C....... Such a regime shift indicates a loss of storage capacity of the seagrass ecosystem, jeopardizing the key role of P. oceanica as a carbon sink in the Mediterranean....

  12. Early colonization on artificial seagrass units and on Posidonia oceanica (L.) Delile leaves

    OpenAIRE

    Pête, D.C.; Lepoint, G.; Bouquegneau, J.-M.; Gobert, S.

    2015-01-01

    Many epiphytes grow on Posidonia oceanica (L.) Delile leaves but early stages of that colonization are not well known. To study this early colonization without destroying the plant, Artificial Seagrass Units (ASUs) were utilised. The first nine days of colonization by macroscopic eukaryotic organisms on natural P. oceanica leaves and on ASUs were studied. The capability of those ASUs to mimic P. oceanica in the long term was also evaluated. Indeed, early colonists of a substrate can influence...

  13. Inhibitory effect of ethanol extract of Nannochloropsis oceanica on lipopolysaccharide-induced neuroinflammation, oxidative stress, amyloidogenesis and memory impairment.

    Science.gov (United States)

    Choi, Ji Yeon; Hwang, Chul Ju; Lee, Hee Pom; Kim, Hee Sik; Han, Sang-Bae; Hong, Jin Tae

    2017-07-11

    Oxidative stress and neuroinflammation is implicated in the pathogenesis and development of Alzheimer's disease (AD). Here, we investigated the suppressive possibility of ethanol extract of Nannochloropsis oceanica (N. oceanica) on memory deficiency along with the fundamental mechanisms in lipopolysaccharide (LPS)-treated mice model. Among several extracts of 32 marine microalgae, ethanol extract of N. oceanica showed the most significant inhibitory effect on nitric oxide (NO) generation, NF-κB activity and β-secretase activity in cultured BV-2 cells, neuronal cells and Raw 264.7 cells. Ethanol extract of N. oceanica (50, 100 mg/kg) also ameliorated LPS (250 μg/kg)-induced memory impairment. We also found that ethanol extract of N. oceanica inhibited the LPS-induced expression of iNOS and COX-2. Furthermore, the production of reactive oxygen species (ROS), malondialdehyde (MDA) level as well as glutathione (GSH) level was also decreased by treatment of ethanol extract of N.oceanica. The ethanol extract of N. oceanica also suppresses IκB degradation as well as p50 and p65 translocation into the nucleus in LPS-treated mice brain. Associated with the inhibitory effect on neuroinflammation and oxidative stress, ethanol extract of N. oceanica suppressed Aβ1-42 generation through down-regulation of APP and BACE1 expression in in vivo. These results suggest that ethanol extract of N. oceanica ameliorated memory impairment via anti-inflammatory, anti-oxidant and anti-amyloidogenic mechanisms.

  14. Sarpa salpa herbivory on shallow reaches of Posidonia oceanica beds

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    Steele, L.

    2014-06-01

    Full Text Available Here, we examined the temporal and small–scale spatial variability of grazing by the herbivorous fish Sarpa salpa on shallow beds of the temperate seagrass Posidonia oceanica. Herbivory intensity expressed as the percent of leaf area taken by fish bites was higher in September 2006 than in February 2007, and at 0.5 m than at 1.5 m during both sampling times. All S. salpa feeding at the shallow locations studied were juveniles, with bite sizes ranging from 0.03 to 0.62 cm2. Juveniles feeding at 1.5 m were larger in February 2007 than in September 2006, as evidenced by significant differences in mean bite size per shoot. However, the larger juveniles feeding at 1.5 m in February 2007 did not appear to feed as frequently as the comparatively smaller juveniles feeding at the same depth in September 2006, as suggested by significant differences in number of bites per shoot. The number of bites per shoot was also lower at 1.5 m than at 0.5 m in February 2007, although mean bite size did not differ significantly between the two depths at that sampling time. In general S. salpa juveniles did not select a particular range of leaf ages when feeding in the study locations, although the juveniles feeding at 1.5 m in September 2006 appeared to select mid–aged leaves. Fish did not show a preference for more epiphytized leaves. These results show that grazing activity by S. salpa juveniles in shallow reaches of P. oceanica meadows may vary temporally and across small changes in depth, which in turn may affect the overall intensity of herbivory on the seagrass.

  15. Genome, functional gene annotation, and nuclear transformation of the heterokont oleaginous alga Nannochloropsis oceanica CCMP1779.

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    Astrid Vieler

    Full Text Available Unicellular marine algae have promise for providing sustainable and scalable biofuel feedstocks, although no single species has emerged as a preferred organism. Moreover, adequate molecular and genetic resources prerequisite for the rational engineering of marine algal feedstocks are lacking for most candidate species. Heterokonts of the genus Nannochloropsis naturally have high cellular oil content and are already in use for industrial production of high-value lipid products. First success in applying reverse genetics by targeted gene replacement makes Nannochloropsis oceanica an attractive model to investigate the cell and molecular biology and biochemistry of this fascinating organism group. Here we present the assembly of the 28.7 Mb genome of N. oceanica CCMP1779. RNA sequencing data from nitrogen-replete and nitrogen-depleted growth conditions support a total of 11,973 genes, of which in addition to automatic annotation some were manually inspected to predict the biochemical repertoire for this organism. Among others, more than 100 genes putatively related to lipid metabolism, 114 predicted transcription factors, and 109 transcriptional regulators were annotated. Comparison of the N. oceanica CCMP1779 gene repertoire with the recently published N. gaditana genome identified 2,649 genes likely specific to N. oceanica CCMP1779. Many of these N. oceanica-specific genes have putative orthologs in other species or are supported by transcriptional evidence. However, because similarity-based annotations are limited, functions of most of these species-specific genes remain unknown. Aside from the genome sequence and its analysis, protocols for the transformation of N. oceanica CCMP1779 are provided. The availability of genomic and transcriptomic data for Nannochloropsis oceanica CCMP1779, along with efficient transformation protocols, provides a blueprint for future detailed gene functional analysis and genetic engineering of Nannochloropsis

  16. Influência da crosta superficial nas taxas de infiltração de água medidas com simulador de chuva e anéis concêntricos

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    R. Levien

    2000-09-01

    Full Text Available A taxa de infiltração de água no solo, conjuntamente com a taxa de chuva, determina a taxa de enxurrada, constituindo medida importante para a previsão de erosão e estudos de conservação do solo. Pode-se medir a taxa de infiltração por meio de um infiltrômetro de cilindros concêntricos (CC ou de um simulador de chuva (SC. A utilização do CC requer menos trabalho do que o SC, mas os resultados obtidos com o CC comumente estão em desacordo com as taxas de infiltração que ocorrem em situações de chuva natural, possivelmente por causa da formação de uma crosta superficial sob chuva. A formação dessa crosta procede tanto de fatores independentes do manejo do solo, como a intensidade da chuva e a textura do solo, quanto de fatores dependentes do manejo, principalmente a resistência ao cisalhamento e a cobertura vegetal. Em situações favoráveis à ocorrência de formação de crosta, espera-se que taxas de infiltração medidas com o CC superestimem as taxas reais durante uma chuva. Para verificar a correlação entre o manejo do solo e a razão das taxas de infiltração obtidas com CC e SC, essas taxas foram medidas por ambos os métodos em dois Podzólicos (Ultissolos da região sul do Brasil. Os tratamentos diferiram com a cobertura vegetal e com a existência de crosta superficial. Medidas da taxa de infiltração com SC foram realizadas com um simulador de chuva com bicos aspersores Veejet 80100, em parcelas de 3,5 x 11,0 m, gerando chuva de intensidade de 64,2 mm h-1, durante 100 a 150 minutos. As parcelas foram delimitadas com chapas de metal e a enxurrada foi coletada no lado inferior por três segundos a cada três minutos. O CC consistiu de dois cilindros (diâmetros de 0,30 e 0,60 m, cravados no solo até 0,10 m pouco antes da determinação com o SC. A área dentro dos anéis foi inundada e as taxas de infiltração foram registradas dentro do anel interior, em intervalos de tempo regulares, com três repeti

  17. Verification of mutagen function of Zeocin in Nannochloropsis oceanica through transcriptome analysis

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    Lin, Genmei; Wang, Yamei; Guo, Li; Ding, Haiyan; Hu, Yongmei; Liang, Sijie; Zhang, Zhongyi; Yang, Guanpin

    2017-06-01

    Zeocin can cause double strand breaks of DNA and thus is frequently used as a selective antibiotic of eukaryotic Sh ble transformants. In non-transformation system, Zeocin may function as a mutagen if not totally lethal. To verify such function of Zeocin, we mutated Nannochloropsis oceanica by increasing the concentration of Zeocin in medium gradually, and isolated a N. oceanica strain (single cell culture) which survived Zeocin up to 10.0 μg mL-1. The Zeocin-tolerant strain entered the exponential growth phase later and grew slower than the wild strain. Transcriptome profiling showed that the Zeocin-tolerant N. oceanica strain survived Zeocin mainly by adapting (heritable), rather than acclimating (plastic) to Zeocin. Hence mutating N. oceanica with Zeocin was approved effective. Meanwhile, the physiological characteristics of this Zeocin-tolerant strain were demonstrated. As we proposed, N. oceanica tolerated Zeocin by strengthening its protein degradation and antioxidation. The genes controlling cell division and cellular response to stimuli may also have played important roles in the reduction of growth and the tolerance to Zeocin. Our findings evidenced that Zeocin can serve as an appropriate mutagen of microalgae. Creating variations through mutation with Zeocin may help to study the genetic basis of the traits of this monoploidy and asexual microalga, as well as improve its production.

  18. Potential adsorption of methylene blue from aqueous solution using green macroalgaePosidonia oceanica.

    Science.gov (United States)

    Allouche, F.-N.; Yassaa, N.

    2018-03-01

    The use of inexpensive biological materials, such as marine algae for removing dyes from contaminated industrial effluents appears as a potential alternative method. The aim of this study is to investigate the aptitude of marine macroalgae Posidonia Oceanica local biomass abundant on the coasts of Algeria for selective sorption of methylene blue (MB) from an aqueous solution in batch experiments at 20 °C. A maximum percentage removal of Posidonia oceanica occurs at pH 5. Equilibrium isotherm data were analyzed using the Langmuir and the Freundlich isotherms. The adsorption equilibrium of methylene blue was best describe by Langmuir model than the Freundlich model. The maximum sorption capacity was 357 mgg-1at pH 5. The sorption data were very well described by the pseudo-second-order model. Keywords: Posidonia oceanica, Methylene blue (MB), Biosorption, Isotherm Equilibrium, Kinetics; Modelling.

  19. Engineering the Chloroplast Genome of Oleaginous Marine Microalga Nannochloropsis oceanica

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    Qinhua Gan

    2018-04-01

    Full Text Available Plastid engineering offers an important tool to fill the gap between the technical and the enormous potential of microalgal photosynthetic cell factory. However, to date, few reports on plastid engineering in industrial microalgae have been documented. This is largely due to the small cell sizes and complex cell-wall structures which make these species intractable to current plastid transformation methods (i.e., biolistic transformation and polyethylene glycol-mediated transformation. Here, employing the industrial oleaginous microalga Nannochloropsis oceanica as a model, an electroporation-mediated chloroplast transformation approach was established. Fluorescent microscopy and laser confocal scanning microscopy confirmed the expression of the green fluorescence protein, driven by the endogenous plastid promoter and terminator. Zeocin-resistance selection led to an acquisition of homoplasmic strains of which a stable and site-specific recombination within the chloroplast genome was revealed by sequencing and DNA gel blotting. This demonstration of electroporation-mediated chloroplast transformation opens many doors for plastid genome editing in industrial microalgae, particularly species of which the chloroplasts are recalcitrant to chemical and microparticle bombardment transformation.

  20. Is Posidonia oceanica regression a general feature in the Mediterranean Sea?

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    M. BONACORSI

    2013-03-01

    Full Text Available Over the last few years, a widespread regression of Posidonia oceanica meadows has been noticed in the Mediterranean Sea. However, the magnitude of this decline is still debated. The objectives of this study are (i to assess the spatio-temporal evolution of Posidonia oceanica around Cap Corse (Corsica over time comparing available ancient maps (from 1960 with a new (2011 detailed map realized combining different techniques (aerial photographs, SSS, ROV, scuba diving; (ii evaluate the reliability of ancient maps; (iii discuss observed regression of the meadows in relation to human pressure along the 110 km of coast. Thus, the comparison with previous data shows that, apart from sites clearly identified with the actual evolution, there is a relative stability of the surfaces occupied by the seagrass Posidonia oceanica. The recorded differences seem more related to changes in mapping techniques. These results confirm that in areas characterized by a moderate anthropogenic impact, the Posidonia oceanica meadow has no significant regression and that the changes due to the evolution of mapping techniques are not negligible. However, others facts should be taken into account before extrapolating to the Mediterranean Sea (e.g. actually mapped surfaces and assessing the amplitude of the actual regression.

  1. Genetic indicators of iron limitation in wild populations of Thalassiosira oceanica from the northeast Pacific Ocean.

    Science.gov (United States)

    Chappell, P Dreux; Whitney, LeAnn P; Wallace, Joselynn R; Darer, Adam I; Jean-Charles, Samua; Jenkins, Bethany D

    2015-03-01

    Assessing the iron (Fe) nutritional status of natural diatom populations has proven challenging as physiological and molecular responses can differ in diatoms of the same genus. We evaluated expression of genes encoding flavodoxin (FLDA1) and an Fe-starvation induced protein (ISIP3) as indicators of Fe limitation in the marine diatom Thalassiosira oceanica. The specificity of the response to Fe limitation was tested in cultures grown under Fe- and macronutrient-deficient conditions, as well as throughout the diurnal light cycle. Both genes showed a robust and specific response to Fe limitation in laboratory cultures and were detected in small volume samples collected from the northeast Pacific, demonstrating the sensitivity of this method. Overall, FLDA1 and ISIP3 expression was inversely related to Fe concentrations and offered insight into the Fe nutritional health of T. oceanica in the field. As T. oceanica is a species tolerant to low Fe, indications of Fe limitation in T. oceanica populations may serve as a proxy for severe Fe stress in the overall diatom community. At two shallow coastal locations, FLD1A and ISIP3 expression revealed Fe stress in areas where dissolved Fe concentrations were high, demonstrating that this approach may be powerful for identifying regions where Fe supply may not be biologically available.

  2. Physiological responses of the seagrass Posidonia oceanica as indicators of fish farm impact

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Marta [Departament d' Ecologia, Universitat de Barcelona Avda. Diagonal 645, 08028 Barcelona (Spain); Garcia, Tania [Departament d' Ecologia, Universitat de Barcelona Avda. Diagonal 645, 08028 Barcelona (Spain)], E-mail: irulagun@hotmail.com; Invers, Olga [Departament d' Ecologia, Universitat de Barcelona Avda. Diagonal 645, 08028 Barcelona (Spain); Ruiz, Juan Manuel [Instituto Espanol de Oceanografia C/Varadero 1, 30740 San Pedro del Pinatar, Murcia (Spain)

    2008-05-15

    The development of aquaculture along the Mediterranean coastline degrades the marine environment, in particular Posidonia oceanica meadows, which, in extreme cases, show high mortality. Here we studied the effects of organic matter and nutrient input from the effluents of three fish farms, located along the Mediterranean coast, on P. oceanica physiology. For this purpose, we measured physiological variables such as total nitrogen (N) content, free amino acid (FAA) concentration and composition, N stable isotope ratio ({delta}{sup 15}N), total phosphorus (P) content and total non-structural carbohydrate (TNC) content in plant tissues and epiphytes affected by organic discharges (highly impacted stations: HI, and less impacted stations: LI) and compared these results with those obtained in references sites (control stations: C). For all the descriptors analyzed in P. oceanica epiphytes, the values recorded in the vicinity of cages were, in general, much higher than those in C. Leaves did not respond consistently in any case. Total N content and {delta}{sup 15}N in epiphytes together with the total P content in rhizomes and epiphytes were the physiological descriptors that showed the most consistent responses to fish farm effluents. On the basis of these observations, we conclude that fish farm activities strongly affect the physiological parameters of nearby P. oceanica meadows. We propose that changes in these physiological parameters may be useful indicators of marine environmental degradation in studies that monitor the effects of fish farming.

  3. Genome, Functional Gene Annotation, and Nuclear Transformation of the Heterokont Oleaginous Alga Nannochloropsis oceanica CCMP1779

    Science.gov (United States)

    2012-11-15

    Hydrogen production Hydrogen produced by microalgae has long been discussed as a possible sustainable transportation fuel source as electrons derived...2002) Long chain polyunsaturated fatty acid production and partitioning to triacylglycerols in four microalgae . Phytochemistry 61: 15–24. 13. Sukenik...industrial production of high-value lipid products . First success in applying reverse genetics by targeted gene replacement makes Nannochloropsis oceanica

  4. Magnetically modified Posidonia oceanica biomass as an adsorbent for organic dyes removal

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Ashoura, N.; Maděrová, Z.; Pospíšková, K.; Baldíková, E.; Šafaříková, Miroslava

    2016-01-01

    Roč. 17, č. 2 (2016), s. 351-358 ISSN 1108-393X Institutional support: RVO:60077344 Keywords : Posidonia oceanica * Neptune balls * magnetic biomass * organic dyes * adsorbent Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.683, year: 2016

  5. Evidences of adaptive traits to rocky substrates undermine paradigm of habitat preference of the Mediterranean seagrass Posidonia oceanica

    Science.gov (United States)

    Badalamenti, Fabio; Alagna, Adriana; Fici, Silvio

    2015-03-01

    Posidonia oceanica meadows are acknowledged as one of the most valuable ecosystems of the Mediterranean Sea. P. oceanica has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. Here we document for the first time the extensive presence of sticky hairs covering P. oceanica seedling roots. Adhesive root hairs allow the seedlings to firmly anchor to rocky substrates with anchorage strength values up to 5.23 N, regardless of the presence of algal cover and to colonise bare rock without the need for precursor assemblages to facilitate settlement. Adhesive root hairs are a morphological trait common on plants living on rocks in high-energy habitats, such as the riverweed Podostemaceae and the seagrass Phyllospadix scouleri. The presence of adhesive root hairs in P. oceanica juveniles suggests a preference of this species for hard substrates. Such an adaptation leads to hypothesize a new microsite driven bottleneck in P. oceanica seedling survival linked to substrate features. The mechanism described can favour plant establishment on rocky substrates, in contrast with traditional paradigms. This feature may have strongly influenced P. oceanica pattern of colonisation through sexual propagules in both the past and present.

  6. Interaction between Posidonia oceanica meadows upper limit and hydrodynamics of four Mediterranean beaches

    Science.gov (United States)

    De Muro, Sandro; Ruju, Andrea; Buosi, Carla; Porta, Marco; Passarella, Marinella; Ibba, Angelo

    2017-04-01

    Posidonia oceanica meadow is considered to play an important role in the coastal geomorphology of Mediterranean beach systems. In particular, the importance of the meadow in protecting the coastline from erosion is well-recognized. Waves are attenuated by greater friction across seagrass meadows, which have the capacity to reduce water flow and therefore increase sediment deposition and accumulation as well as beach stability. The P. oceanica meadow upper limit usually occurs within the most dynamic zone of the beach system. Considering the great attention paid in the literature to the connection between the growth of P. oceanica and coastal hydrodynamics (Infantes et al., 2009; Vacchi et al., 2014; De Muro et al., 2016, 2017), this study aims at extending the previous work by investigating the combined influence of hydrodynamic parameters (e.g., wave-induced main currents and wave orbital velocity at the bottom) and different types of sea bottom (e.g., soft sediment, rocky substrates) on the position of the upper limit of the P. oceanica meadow. We applied this approach to 4 Mediterranean beach systems located on the Sardinian coastline (3 on the South and 1 on the North) and characterized by a wide range of orientations and incoming wave conditions. On these beaches, the extension of the P. oceanica meadows and the bathymetry have been obtained through detailed surveying campaigns and aerial photo analysis. In addition, high spatial resolution wave hydrodynamics have been reconstructed by running numerical simulations with Delft 3D. Offshore wave climate has been reconstructed by using measured datasets for those beaches that have a nearby buoy whose dataset is representative of the incoming wave conditions for that particular stretch of coast. Whereas, for those beaches with no availability of a representative measured dataset, wave climate has been analyzed from the NOAA hindcast dataset. From the whole range of incoming wave directions in deep waters, we

  7. Trace metal distributions in Posidonia oceanica and sediments from Taranto Gulf (Ionian Sea, Southern Italy

    Directory of Open Access Journals (Sweden)

    A. DI LEO

    2013-03-01

    Full Text Available Distribution of metals (Hg, Pb, Sn, Cu, Cd and Zn was determined in sediments and in different tissues of Posidonia oceanica collected from San Pietro Island, Taranto Gulf (Ionian Sea, Southern Italy. In seagrass, results, compared with metal concentrations in sediments, showed that the highest concentrations of Hg, Pb, Sn and Cu were found in the roots, while in the green leaves were found the highest levels of Cd and Zn. Instead the lowest metal concentrations were found in the basal part of the leaf. Levels of  metals in the leaves were similar to those found by other authors in uncontaminated areas of the Mediterranean Sea. Mercury levels in roots were correlated to levels in sediments. This could demonstrate the plant memorizes sediments contamination . This study reinforces the usefulness and the relevance of Posidonia oceanica as an indicator of spatial metal contamination and an interesting tool for environmental quality evaluation.

  8. Occurrence and distribution of different bed types of seagrass Posidonia oceanica around the Maltese Islands

    Directory of Open Access Journals (Sweden)

    J.A. BORG

    2009-12-01

    Full Text Available The small-scale distribution of Posidonia oceanica bed types were mapped at four locations off the northern coast of the Maltese Islands, using aerial photography supplemented by surveys using SCUBA diving. Results showed a similar pattern of occurrence of the seagrass at all locations surveyed. In shallow waters (2 m – 4 m, P. oceanicaoccurred as patches of variable size on a rocky and/or sandy substratum. In deeper waters (5 m – 10 m, the patches of seagrass were often replaced by reticulate beds consisting of P. oceanicainterspersed with areas of bare sand. Deeper still (11 m – 13 m, a transition from reticulate to continuous beds occurred. Continuous beds extended to depths of around 25 - 30 m and eventually became reticulate or patchy in deeper waters (>25 m. Values of total seagrass percentage cover increased, while the ratio of fragmented:continuous bed cover decreased for the four study locations on moving southwards (Ramla Bay to St Thomas Bay, indicating that P. oceanica habitat was more abundant and less fragmented in the south-eastern parts of the Maltese Islands. However, values calculated using an exposure index did not did indicate a relationship between exposure and the observed decease in fragmentation of seagrass beds on moving northwest to southwest along the north-eastern coast. Data from the four sites surveyed, together with data from other surveys, were used to show the large-scale distribution of P. oceanica beds around the Maltese Islands. The implications of the study findings for the conservation and management of P. oceanica habitat around the Maltese Islands are discussed.

  9. Occurrence of mucous aggregates and their impact on Posidonia oceanica beds.

    Science.gov (United States)

    Lorenti, Maurizio; Buia, Maria Cristina; Di Martino, Vincenzo; Modigh, Monica

    2005-12-15

    Mucous macro-aggregates of both pelagic and benthic origin are recurrently observed in the meadows formed by the seagrass Posidonia oceanica around the island of Ischia (Gulf of Naples, Italy). In the past two decades, major events occurred in 1991, 1993 and 2000, when a thick layer of mucilage covered vast areas of the meadows. To investigate the environmental triggers for mucilage formation and the effects of macro-aggregates on the functional and structural status of P. oceanica, a number of abiotic and biotic parameters were monitored over three years within the frame of a research project on Adriatic and Tyrrhenian mucilages (MAT). Basic environmental parameters (salinity, temperature, irradiance, dissolved oxygen concentration) in the water column and inorganic nutrient concentrations above and within P. oceanica meadows were measured. As descriptors of the status of the seagrass, shoot density and the nitrogen content of the leaves were monitored. Moreover, a reconstructive technique (lepidochronology) was employed to track back annual plant production. During the three-year study, mucous aggregates produced by benthic algae were observed in spring-summer and a major event of macro-aggregates of pelagic origin affecting P. oceanica canopy was observed in autumn 2000. Each of these episodes was observed for a few weeks to one month. We hypothesize nutrient limitation to explain the short duration of the benthic algal blooms that were responsible of macroaggregate formation; a highly dynamic circulation resulted in the dispersion of the pelagic aggregates deposited on the meadows. None of the descriptors of the structure of the meadow and of plant performance showed any obvious alterations in relation to the occurrence of mucilage coverage. Presumably, the short duration of the mucilage episodes recorded were not enough to induce such alterations, at least at the temporal and spatial scales considered.

  10. The impact of dredge-fill on Posidonia oceanica seagrass meadows: regression and patterns of recovery.

    Science.gov (United States)

    Badalamenti, Fabio; Alagna, Adriana; D'Anna, Giovanni; Terlizzi, Antonio; Di Carlo, Giuseppe

    2011-03-01

    Posidonia oceanica meadows can be severely damaged by dredge-fill operations. We report on the construction of gas pipelines that occurred between 1981 and 1993 in SW Sicily, Italy. A large portion of the meadow was mechanically removed, and the excavated trench was filled with a mosaic of substrates, ranging from sand to consolidated rock debris. Meadow loss and recovery were quantified over 7 years after the end of operations. We recorded an overall loss of 81.20 ha of meadow. Substrate strongly affected recovery as the percent cover by P. oceanica consistently increased on calcareous rubble, reaching values of 44.37 ± 3.05% in shallow sites after 7 years, whereas no significant increase occurred on other substrates. As in the Mediterranean Sea exploitation of coastal areas continues to grow with consequent impacts on P. oceanica meadows, this case study illustrates how artificial rubble-like materials could be employed to support the restoration of damaged meadows. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. The utilization of natural soda resource of Ordos in the cultivation of Nannochloropsis oceanica.

    Science.gov (United States)

    Pan, Yanfei; Yang, Haibo; Meng, Yingying; Liu, Jiao; Shen, Peili; Wu, Peichun; Cao, Xupeng; Xue, Song

    2016-01-01

    Nannochloropsis oceanica is famous for its strong environmental adaptability and oil-richness, especially high eicosapentaenoic acid (EPA) content. In this report, the possibility and cultivation parameters for N. oceanica using natural crude soda were testified and compared with seawater culture. To keep a suitable salinity range, different ratio of sea salt addition into soda lake water were used and the growth, lipid content, Fv/Fm and fatty acids profiling were inspected with nitrogen repletion or depletion. The results showed the best performance were achieved while 18g/L (salinity 25‰) sea salt was added into crude soda solution. The μmax and EPA content in fatty acids were 0.72/0.42 and 36%/23% in 500mL/100L bioreactor cultivations respectively, which maintained a relative high productivity to other reports. By comparing the growth and operations with Spirulina production, the feasibility of N. Oceanica in Ordos was proved on both technical and economical point of view. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Transcriptional coordination of physiological responses in Nannochloropsis oceanica CCMP1779 under light/dark cycles.

    Science.gov (United States)

    Poliner, Eric; Panchy, Nicholas; Newton, Linsey; Wu, Guangxi; Lapinsky, Andrew; Bullard, Blair; Zienkiewicz, Agnieszka; Benning, Christoph; Shiu, Shin-Han; Farré, Eva M

    2015-09-01

    Nannochloropsis oceanica CCMP1779 is a marine unicellular stramenopile and an emerging reference species for basic research on oleogenic microalgae with biotechnological relevance. We investigated its physiology and transcriptome under light/dark cycles. We observed oscillations in lipid content and a predominance of cell division in the first half of the dark phase. Globally, more than 60% of the genes cycled in N. oceanica CCMP1779, with gene expression peaking at different times of the day. Interestingly, the phase of expression of genes involved in certain biological processes was conserved across photosynthetic lineages. Furthermore, in agreement with our physiological studies we found the processes of lipid metabolism and cell division enriched in cycling genes. For example, there was tight coordination of genes involved in the lower part of glycolysis, fatty acid synthesis and lipid production at dawn preceding lipid accumulation during the day. Our results suggest that diel lipid storage plays a key role for N. oceanica CCMP1779 growth under natural conditions making this alga a promising model to gain a basic mechanistic understanding of triacylglycerol production in photosynthetic cells. Our data will help the formulation of new hypotheses on the role of cyclic gene expression in cell growth and metabolism in Nannochloropsis. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  13. Architecture of the light-harvesting apparatus of the eustigmatophyte alga Nannochloropsis oceanica.

    Science.gov (United States)

    Litvín, Radek; Bína, David; Herbstová, Miroslava; Gardian, Zdenko

    2016-12-01

    We present proteomic, spectroscopic, and phylogenetic analysis of light-harvesting protein (Lhc) function in oleaginous Nannochloropsis oceanica (Eustigmatophyta, Stramenopila). N. oceanica utilizes Lhcs of multiple classes: Lhcr-type proteins (related to red algae LHCI), Lhcv (VCP) proteins (violaxanthin-containing Lhcs related to Lhcf/FCP proteins of diatoms), Lhcx proteins (related to Lhcx/LhcSR of diatoms and green algae), and Lhc proteins related to Red-CLH of Chromera velia. Altogether, 17 Lhc-type proteins of the 21 known from genomic data were found in our proteomic analyses. Besides Lhcr-type antennas, a RedCAP protein and a member of the Lhcx protein subfamily were found in association with Photosystem I. The free antenna fraction is formed by trimers of a mixture of Lhcs of varied origins (Lhcv, Lhcr, Lhcx, and relatives of Red-CLH). Despite possessing several proteins of the Red-CLH-type Lhc clade, N. oceanica is not capable of chromatic adaptation under the same conditions as the diatom Phaeodactylum tricornutum or C. velia. In addition, a naming scheme of Nannochloropsis Lhcs is proposed to facilitate further work.

  14. The Posidonia oceanica marine sedimentary record: A Holocene archive of heavy metal pollution.

    Science.gov (United States)

    Serrano, O; Mateo, M A; Dueñas-Bohórquez, A; Renom, P; López-Sáez, J A; Martínez Cortizas, A

    2011-10-15

    The study of a Posidonia oceanica mat (a peat-like marine sediment) core has provided a record of changes in heavy metal abundances (Fe, Mn, Ni, Cr, Cu, Pb, Cd, Zn, As and Al) since the Mid-Holocene (last 4470yr) in Portlligat Bay (NW Mediterranean). Metal contents were determined in P. oceanica. Both, the concentration records and the results of principal components analysis showed that metal pollution in the studied bay started ca. 2800yr BP and steadily increased until present. The increase in Fe, Cu, Pb, Cd, Zn and As concentrations since ca. 2800yr BP and in particular during Greek (ca. 2680-2465cal BP) and Roman (ca. 2150-1740cal BP) times shows an early anthropogenic pollution rise in the bay, which might be associated with large- and short-scale cultural and technological development. In the last ca. 1000yr the concentrations of heavy metals, mainly derived from anthropogenic activities, have significantly increased (e.g. from ~15 to 47μg g(-1) for Pb, ~23 to 95μg g(-1) for Zn and ~8 to 228μg g(-1) for As). Our study demonstrates for the first time the uniqueness of P. oceanica meadows as long-term archives of abundances, patterns, and trends of heavy metals during the Late Holocene in Mediterranean coastal ecosystems. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Metal contamination of Posidonia oceanica meadows along the Corsican coastline (Mediterranean)

    Energy Technology Data Exchange (ETDEWEB)

    Lafabrie, C. [University of Corsica, Faculty of Sciences, Equipe Ecosystemes Littoraux, BP 52, 20250 Corte (France)], E-mail: lafabrie@univ-corse.fr; Pergent-Martini, C.; Pergent, G. [University of Corsica, Faculty of Sciences, Equipe Ecosystemes Littoraux, BP 52, 20250 Corte (France)

    2008-01-15

    The aim of this study is to determine metal (Cd, Co, Cr, Hg, Ni, Pb) concentrations in Posidonia oceanica tissues along the Corsican coastline. The results show that except for Cr, all the metals are preferentially accumulated in the blades; this is particularly interesting as it means that future metal analyses may be carried out only on the blades avoiding thus the removal of the shoots. Moreover, they show that metal concentrations may reflect the 'background noise' of the Mediterranean Sea. Station 15 (Canari) can however be distinguished from the others due to its high Co, Cr and Ni concentrations. This result may be related to the presence of a previous asbestos mine, located near this station. Therefore, this study reinforces the usefulness and the relevance of Posidonia oceanica as a tracer of spatial metal contamination and as an interesting tool for water quality evaluation. - The seagrass Posidonia oceanica is a relevant tracer of spatial metal contamination and an interesting tool for water quality evaluation.

  16. Metal contamination of Posidonia oceanica meadows along the Corsican coastline (Mediterranean)

    International Nuclear Information System (INIS)

    Lafabrie, C.; Pergent-Martini, C.; Pergent, G.

    2008-01-01

    The aim of this study is to determine metal (Cd, Co, Cr, Hg, Ni, Pb) concentrations in Posidonia oceanica tissues along the Corsican coastline. The results show that except for Cr, all the metals are preferentially accumulated in the blades; this is particularly interesting as it means that future metal analyses may be carried out only on the blades avoiding thus the removal of the shoots. Moreover, they show that metal concentrations may reflect the 'background noise' of the Mediterranean Sea. Station 15 (Canari) can however be distinguished from the others due to its high Co, Cr and Ni concentrations. This result may be related to the presence of a previous asbestos mine, located near this station. Therefore, this study reinforces the usefulness and the relevance of Posidonia oceanica as a tracer of spatial metal contamination and as an interesting tool for water quality evaluation. - The seagrass Posidonia oceanica is a relevant tracer of spatial metal contamination and an interesting tool for water quality evaluation

  17. Palaeoclimatic conditions in the Mediterranean explain genetic diversity of Posidonia oceanica seagrass meadows

    KAUST Repository

    Chefaoui, Rosa M.

    2017-05-26

    Past environmental conditions in the Mediterranean Sea have been proposed as main drivers of the current patterns of distribution of genetic structure of the seagrass Posidonia oceanica, the foundation species of one of the most important ecosystems in the Mediterranean Sea. Yet, the location of cold climate refugia (persistence regions) for this species during the Last Glacial Maximum (LGM) is not clear, precluding the understanding of its biogeographical history. We used Ecological Niche Modelling together with existing phylogeographic data to locate Pleistocene refugia in the Mediterranean Sea and to develop a hypothetical past biogeographical distribution able to explain the genetic diversity presently found in P. oceanica meadows. To do that, we used an ensemble approach of six predictive algorithms and two Ocean General Circulation Models. The minimum SST in winter and the maximum SST in summer allowed us to hindcast the species range during the LGM. We found separate glacial refugia in each Mediterranean basin and in the Central region. Altogether, the results suggest that the Central region of the Mediterranean Sea was the most relevant cold climate refugium, supporting the hypothesis that long-term persistence there allowed the region to develop and retain its presently high proportion of the global genetic diversity of P. oceanica.

  18. Recruitment and Patch Establishment by Seed in the Seagrass Posidonia oceanica: Importance and Conservation Implications

    Directory of Open Access Journals (Sweden)

    Elena Balestri

    2017-06-01

    Full Text Available Seagrasses are declining globally, and deeper understanding is needed on the recruitment potential and distribution of new populations for many threatened species to support conservation planning in the face of climate change. Recruitment of Posidonia oceanica, a threatened seagrass endemic to the Mediterranean, has long been considered rare due to infrequent flowering, but mounting evidence demonstrates that the species is responding to a changing climate through greater reproductive effort. Due to the fragmentary information on recruit occurrence and distribution, little is known about reproductive success in the species and its contribution to persistence. We assembled P. oceanica recruitment data from published and unpublished sources, including our own, to examine the frequency and extent of recruitment events (establishment of seedlings in a site, seedling growth potential and habitat characteristics at recruitment sites. Results show that at least one recruitment event has occurred about every 3 years, and 18 localities were colonized at least one time since the first seedling record in 1986. Notably, consistently high seedling inputs were observed in four localities of the Western Mediterranean. Seedlings established mainly on unoccupied substrate areas along the coasts of islands, in sheltered sites and at shallower depths (<3 m than the upper limit of adjacent P. oceanica meadows. Seedling establishment occurred more frequently on rocky than on sandy substrate, and rarely on dead “matte” or meadows of the seagrass Cymodocea nodosa. The chance of colonization success on rock was two times higher than on sand. Our 11 years of observations have allowed for the first time the documentation of the formation and development of patches by P. oceanica seed. These findings contradict the historical assumption that sexual recruitment is rare and usually unsuccessful for P. oceanica, and highlight the potential importance of recruitment for

  19. Effects of fish farm waste on Posidonia oceanica meadows: Synthesis and provision of monitoring and management tools

    International Nuclear Information System (INIS)

    Holmer, Marianne; Argyrou, Marina; Dalsgaard, Tage; Danovaro, Roberto; Diaz-Almela, Elena; Duarte, Carlos M.; Frederiksen, Morten; Grau, Antoni; Karakassis, Ioannis; Marba, Nuria; Mirto, Simone; Perez, Marta; Pusceddu, Antonio; Tsapakis, Manolis

    2008-01-01

    This paper provides a synthesis of the EU project MedVeg addressing the fate of nutrients released from fish farming in the Mediterranean with particular focus on the endemic seagrass Posidonia oceanica habitat. The objectives were to identify the main drivers of seagrass decline linked to fish farming and to provide sensitive indicators of environmental change, which can be used for monitoring purposes. The sedimentation of waste particles in the farm vicinities emerges as the main driver of benthic deterioration, such as accumulation of organic matter, sediment anoxia as well as seagrass decline. The effects of fish farming on P. oceanica meadows are diverse and complex and detected through various metrics and indicators. A safety distance of 400 m is suggested for management of P. oceanica near fish farms followed by establishment of permanent seagrass plots revisited annually for monitoring the health of the meadows

  20. Effects of fish farm waste on Posidonia oceanica meadows: Synthesis and provision of monitoring and management tools

    Energy Technology Data Exchange (ETDEWEB)

    Holmer, Marianne [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)], E-mail: holmer@biology.sdu.dk; Argyrou, Marina [Marine Environment Division, Department of Fisheries and Marine Research, Ministry of Agriculture, Natural Resources and Environment, 101 Bethleem Street, 1416 Nicosia (Cyprus); Dalsgaard, Tage [Department of Marine Ecology, National Environmental Research Institute, Aarhus University, Vejlsovej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Danovaro, Roberto [Department of Marine Science, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Diaz-Almela, Elena; Duarte, Carlos M. [IMEDEA (CSIC-UIB), Miquel Marques 21, 07190 Esporles (Illes Balears) (Spain); Frederiksen, Morten [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Grau, Antoni [Direccio General de Pesca, Conselleria d' Agricultura i Pesca, Govern de les Illes Balears, Foners 10, 07006 Palma de Mallorca (Illes Balears) (Spain); Karakassis, Ioannis [Marine Ecology Laboratory, Biology Department, University of Crete, Heraklion, 71409 Crete (Greece); Marba, Nuria [IMEDEA (CSIC-UIB), Miquel Marques 21, 07190 Esporles (Illes Balears) (Spain); Mirto, Simone [Institute for the Marine Coastal Environment, National Council of Research, Spianata S. Raineri, 86, 98122 Messina (Italy); Perez, Marta [Departament d' Ecologia, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona (Spain); Pusceddu, Antonio [Department of Marine Science, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Tsapakis, Manolis [Institute of Oceanography, Hellenic Center for Marine Research, P.O. Box 2214, GR 71003 Heraklion, Crete (Greece)

    2008-09-15

    This paper provides a synthesis of the EU project MedVeg addressing the fate of nutrients released from fish farming in the Mediterranean with particular focus on the endemic seagrass Posidonia oceanica habitat. The objectives were to identify the main drivers of seagrass decline linked to fish farming and to provide sensitive indicators of environmental change, which can be used for monitoring purposes. The sedimentation of waste particles in the farm vicinities emerges as the main driver of benthic deterioration, such as accumulation of organic matter, sediment anoxia as well as seagrass decline. The effects of fish farming on P. oceanica meadows are diverse and complex and detected through various metrics and indicators. A safety distance of 400 m is suggested for management of P. oceanica near fish farms followed by establishment of permanent seagrass plots revisited annually for monitoring the health of the meadows.

  1. (1)H, (15)N and (13)C resonance assignments of translationally-controlled tumor protein from photosynthetic microalga Nannochloropsis oceanica.

    Science.gov (United States)

    Yao, Xingzhe; Xiao, Yan; Cui, Qiu; Feng, Yingang

    2015-10-01

    Translationally-controlled tumor protein (TCTP) is a eukaryote-conserved protein with crucial roles in cellular growth. It has also been proposed that plant TCTP has functions specific to plant, while no structure of TCTP from photosynthetic organism has been reported. Nannochloropsis is a photosynthetic microalga with high yield of lipid and high-value polyunsaturated fatty acid, which is promising for biodiesel production. Study of growth-related proteins may provide new clue for improving the yield of lipid. TCTP from Nannochloropsis oceanica shares low sequence identity with structure-known TCTPs. Here we reported the NMR resonance assignments of TCTP from N. oceanica for further structural and functional studies.

  2. Chemoreception of the Seagrass Posidonia Oceanica by Benthic Invertebrates is Altered by Seawater Acidification.

    Science.gov (United States)

    Zupo, Valerio; Maibam, Chingoileima; Buia, Maria Cristina; Gambi, Maria Cristina; Patti, Francesco Paolo; Scipione, Maria Beatrice; Lorenti, Maurizio; Fink, Patrick

    2015-08-01

    Several plants and invertebrates interact and communicate by means of volatile organic compounds (VOCs). These compounds may play the role of infochemicals, being able to carry complex information to selected species, thus mediating inter- or intra-specific communications. Volatile organic compounds derived from the wounding of marine diatoms, for example, carry information for several benthic and planktonic invertebrates. Although the ecological importance of VOCs has been demonstrated, both in terrestrial plants and in marine microalgae, their role as infochemicals has not been demonstrated in seagrasses. In addition, benthic communities, even the most complex and resilient, as those associated to seagrass meadows, are affected by ocean acidification at various levels. Therefore, the acidification of oceans could produce interference in the way seagrass-associated invertebrates recognize and choose their specific environments. We simulated the wounding of Posidonia oceanica leaves collected at two sites (a control site at normal pH, and a naturally acidified site) off the Island of Ischia (Gulf of Naples, Italy). We extracted the VOCs and tested a set of 13 species of associated invertebrates for their specific chemotactic responses in order to determine if: a) seagrasses produce VOCs playing the role of infochemicals, and b) their effects can be altered by seawater pH. Our results indicate that several invertebrates recognize the odor of wounded P. oceanica leaves, especially those strictly associated to the leaf stratum of the seagrass. Their chemotactic reactions may be modulated by the seawater pH, thus impairing the chemical communications in seagrass-associated communities in acidified conditions. In fact, 54% of the tested species exhibited a changed behavioral response in acidified waters (pH 7.7). Furthermore, the differences observed in the abundance of invertebrates, in natural vs. acidified field conditions, are in agreement with these behavioral

  3. The mechanism of the acclimation of Nannochloropsis oceanica to freshwater deduced from its transcriptome profiles

    Science.gov (United States)

    Guo, Li; Yang, Guanpin

    2015-10-01

    In this study, we compared the transcriptomes of Nannochloropsis oceanica cultured in f/2 medium prepared with sea-water and freshwater, respectively, aiming to understand the acclimation mechanism of this alga to freshwater. Differentially expressed genes were mainly assigned to the degradation of cell components, ion transportation, and ribosomal biogenesis. These findings indicate that the algal cells degrade its components (mainly amino acids and fatty acids) to yield excessive energy (ATP) to maintain cellular ion (mainly K+ and Ca2+) homeostasis, while the depletion of amino acids and ATP, and the reduction of ribosomes attenuate the protein translation and finally slow down the cell growth.

  4. Response of Posidonia oceanica seagrass and its epibiont communities to ocean acidification.

    Directory of Open Access Journals (Sweden)

    Katja Guilini

    Full Text Available The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5, which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to

  5. Omega-3 fatty acid obtained from Nannochloropsis oceanica cultures grown under low urea protect against Abeta-induced neural damage.

    Science.gov (United States)

    Lai, Ying-Jang

    2015-05-01

    Amyloid-beta (Abeta) protein is a key factor in the pathogenesis of Alzheimer's disease (AD). Moreover, it has been reported that oxidative stress is involved in the biochemical pathway by which Abeta can lead to neuronal dysfunction. Recently, docosahexaenoic acid (DHA; C22:6) and eicosapentaenoic acid (EPA; C20:5n-3) have been reported to protect against AD. However, these omega-3 fatty acids are frequently obtained from fish oil and may contain heavy metals. In this study, we utilized Nannochloropsis oceanica to produce omega-3 fatty acid. We observed that when urea levels (nitrogen source) were lowered from 2 to 0.2 g/L in Nannochloropsis oceanica cultures, EPA production increased. Moreover, EPA in Nannochloropsis oceanica effectively promoted antioxidant activity to counter the Abeta-induced oxidative stress in Neuro-2A cells. These results indicate that Nannochloropsis oceanica may be potentially used as a therapeutic agent or as a functional food that promotes protection against AD.

  6. Fungal root symbionts of the seagrass Posidonia oceanica in the central Adriatic Sea revealed by microscopy, culturing and 454-pyrosequencing

    Czech Academy of Sciences Publication Activity Database

    Vohník, Martin; Borovec, Ondřej; Župan, I.; Kolařík, Miroslav; Sudová, Radka

    2017-01-01

    Roč. 583, November 16 (2017), s. 107-120 ISSN 0171-8630 Institutional support: RVO:67985939 ; RVO:61388971 Keywords : seagrass es * Posidonia oceanica * root mycobionts Subject RIV: EH - Ecology, Behaviour; EE - Microbiology, Virology (MBU-M) OBOR OECD: Ecology; Microbiology (MBU-M) Impact factor: 2.292, year: 2016

  7. Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery.

    Science.gov (United States)

    Dong, Hong-Po; Williams, Ernest; Wang, Da-zhi; Xie, Zhang-Xian; Hsia, Ru-ching; Jenck, Alizée; Halden, Rolf; Li, Jing; Chen, Feng; Place, Allen R

    2013-06-01

    The Nannochloropsis genus contains oleaginous microalgae that have served as model systems for developing renewable biodiesel. Recent genomic and transcriptomic studies on Nannochloropsis species have provided insights into the regulation of lipid production in response to nitrogen stress. Previous studies have focused on the responses of Nannochloropsis species to short-term nitrogen stress, but the effect of long-term nitrogen deprivation remains largely unknown. In this study, physiological and proteomic approaches were combined to understand the mechanisms by which Nannochloropsis oceanica IMET1 is able to endure long-term nitrate deprivation and its ability to recover homeostasis when nitrogen is amended. Changes of the proteome during chronic nitrogen starvation espoused the physiological changes observed, and there was a general trend toward recycling nitrogen and storage of lipids. This was evidenced by a global down-regulation of protein expression, a retained expression of proteins involved in glycolysis and the synthesis of fatty acids, as well as an up-regulation of enzymes used in nitrogen scavenging and protein turnover. Also, lipid accumulation and autophagy of plastids may play a key role in maintaining cell vitality. Following the addition of nitrogen, there were proteomic changes and metabolic changes observed within 24 h, which resulted in a return of the culture to steady state within 4 d. These results demonstrate the ability of N. oceanica IMET1 to recover from long periods of nitrate deprivation without apparent detriment to the culture and provide proteomic markers for genetic modification.

  8. Posidonia oceanica (L. Delile Ethanolic Extract Modulates Cell Activities with Skin Health Applications

    Directory of Open Access Journals (Sweden)

    Laura Cornara

    2018-01-01

    Full Text Available Seagrasses are high plants sharing adaptive metabolic features with both terrestrial plants and marine algae, resulting in a phytocomplex possibly endowed with interesting biological properties. The aim of this study is to evaluate the in vitro activities on skin cells of an ethanolic extract obtained from the leaves of Posidonia oceanica (L. Delile, family Potamogetonaceae, herein named Posidonia ethanolic extract (PEE. PEE showed high radical scavenging activity, high phenolic content, and resulted rich in chicoric acid, as determined through HPLC-MS analysis. The use of MTT assay on fibroblasts showed a PEE cytotoxicity threshold (IC05 of 50 µg/mL at 48 h, while a sub-toxic dose of 20 µg/mL induced a significant increase of fibroblast growth rate after 10 days. In addition, an ELISA assay revealed that PEE doses of 5 and 10 µg/mL induced collagen production in fibroblasts. PEE induced dose-dependent mushroom tyrosinase inhibition, up to about 45% inhibition at 1000 µg/mL, while 50% reduction of melanin was observed in melanoma cells exposed to 50 µg/mL PEE. Finally, PEE lipolytic activity was assessed by measuring glycerol release from adipocytes following triglyceride degradation. In conclusion, we have collected new data about the biological activities of the phytocomplex of P. oceanica seagrass on skin cells. Our findings indicate that PEE could be profitably used in the development of products for skin aging, undesired hyperpigmentation, and cellulite.

  9. Light availability and temperature, not increased CO2, will structure future meadows of Posidonia oceanica

    KAUST Repository

    Hendriks, Iris E.

    2017-02-15

    We evaluated the photosynthetic performance of Posidonia oceanica during short-term laboratory exposures to ambient and elevated temperatures (24–25°C and 29–30°C) warming and pCO2 (380, 750 and 1000ppm pCO2) under normal and low light conditions (200 and 40μmol photons m−2s−1 respectively). Plant growth was measured at the low light regime and showed a negative response to warming. Light was a critical factor for photosynthetic performance, although we found no evidence of compensation of photosynthetic quantum efficiency in high light. Relative Electron Rate Transport (rETRmax) was higher in plants incubated in high light, but not affected by pCO2 or temperature. The saturation irradiance (Ik) was negatively affected by temperature. We conclude that elevated CO2 does not enhance photosynthetic activity and growth, in the short term for P. oceanica, while temperature has a direct negative effect on growth. Low light availability also negatively affected photosynthetic performance during the short experimental period examined here. Therefore increasing concentrations of CO2 may not compensate for predicted future conditions of warmer water and higher turbidity for seagrass meadows.

  10. Novel bacterial isolate from Permian groundwater, capable of aggregating potential biofuel-producing microalga Nannochloropsis oceanica IMET1.

    Science.gov (United States)

    Wang, Hui; Laughinghouse, Haywood D; Anderson, Matthew A; Chen, Feng; Willliams, Ernest; Place, Allen R; Zmora, Odi; Zohar, Yonathan; Zheng, Tianling; Hill, Russell T

    2012-03-01

    Increasing petroleum costs and climate change have resulted in microalgae receiving attention as potential biofuel producers. Little information is available on the diversity and functions of bacterial communities associated with biofuel-producing algae. A potential biofuel-producing microalgal strain, Nannochloropsis oceanica IMET1, was grown in Permian groundwater. Changes in the bacterial community structure at three temperatures were monitored by two culture-independent methods, and culturable bacteria were characterized. After 9 days of incubation, N. oceanica IMET1 began to aggregate and precipitate in cultures grown at 30°C, whereas cells remained uniformly distributed at 15°C and 25°C. The bacterial communities in cultures at 30°C changed markedly. Some bacteria isolated only at 30°C were tested for their potential for aggregating microalgae. A novel bacterium designated HW001 showed a remarkable ability to aggregate N. oceanica IMET1, causing microalgal cells to aggregate after 3 days of incubation, while the total lipid content of the microalgal cells was not affected. Direct interaction of HW001 and N. oceanica is necessary for aggregation. HW001 can also aggregate the microalgae N. oceanica CT-1, Tetraselmis suecica, and T. chuii as well as the cyanobacterium Synechococcus WH8007. 16S rRNA gene sequence comparisons indicated the great novelty of this strain, which exhibited only 89% sequence similarity with any previously cultured bacteria. Specific primers targeted to HW001 revealed that the strain originated from the Permian groundwater. This study of the bacterial communities associated with potential biofuel-producing microalgae addresses a little-investigated area of microalgal biofuel research and provides a novel approach to harvest biofuel-producing microalgae by using the novel bacterium strain HW001.

  11. Towards Visual Navigation of an Autonomous Underwater Vehicle in Areas with Posidonia Oceanica

    Directory of Open Access Journals (Sweden)

    Francisco Bonin-Font

    2017-12-01

    Full Text Available This paper presents an exhaustive, extensive and detailed experimental assessment of different types of visual key-points in terms of robustness, stability and traceability, in images taken in marine areas densely colonized with Posidonia Oceanica (P.O.. This work has been focused mainly in two issues: a evaluating the  capacity of several image color and contrast enhancing preprocessing techniques to increase the image quality and the number of stable features, and b finding the pair feature detector/descriptor, from a wide range of different combinations, that maximizes the number of inlier correspondences in consecutive frames or frames that close a loop (images that overlap, taken at distant time instants, from different viewpoints or even with different environmental conditions. Conclusions extracted from both evaluations will affect directly the quality of visual odometers and/or the image registration processes involved in visual SLAM approaches.

  12. Activated carbon derived from marine Posidonia Oceanica for electric energy storage

    Directory of Open Access Journals (Sweden)

    N. Boukmouche

    2014-07-01

    Full Text Available In this paper, the synthesis and characterization of activated carbon from marine Posidonia Oceanica were studied. The activated carbon was prepared by a simple process namely pyrolysis under inert atmosphere. The activated carbon can be used as electrodes for supercapacitor devices. X-ray diffraction result revealed a polycrystalline graphitic structure. While scanning electron microscope investigation showed a layered structure with micropores. The EDS analysis showed that the activated carbon contains the carbon element in high atomic percentage. Electrochemical impedance spectroscopy revealed a capacitive behavior (electrostatic phenomena. The specific capacity per unit area of the electrochemical double layer of activated carbon electrode in sulfuric acid electrolyte was 3.16 F cm−2. Cyclic voltammetry and galvanostatic chronopotentiometry demonstrated that the electrode has excellent electrochemical reversibility. It has been found that the surface capacitance was strongly related to the specific surface area and pore size.

  13. Metabolic Remodeling of Membrane Glycerolipids in the Microalga Nannochloropsis oceanica under Nitrogen Deprivation

    Directory of Open Access Journals (Sweden)

    Danxiang Han

    2017-08-01

    Full Text Available HIGHLIGHTSAn electrospray ionization mass spectrometry-based lipidomics method was developed and integrated with transcriptomics to elucidate metabolic remodeling and turnover of microalgal membrane lipids by using Nannochloropsis oceanica as a model.The lack of lipidome analytical tools has limited our ability to gain new knowledge about lipid metabolism in microalgae, especially for membrane glycerolipids. An electrospray ionization mass spectrometry-based lipidomics method was developed for Nannochloropsis oceanica IMET1, which resolved 41 membrane glycerolipids molecular species belonging to eight classes. Changes in membrane glycerolipids under nitrogen deprivation and high-light (HL conditions were uncovered. The results showed that the amount of plastidial membrane lipids including monogalactosyldiacylglycerol, phosphatidylglycerol, and the extraplastidic lipids diacylglyceryl-O-4′-(N, N, N,-trimethyl homoserine and phosphatidylcholine decreased drastically under HL and nitrogen deprivation stresses. Algal cells accumulated considerably more digalactosyldiacylglycerol and sulfoquinovosyldiacylglycerols under stresses. The genes encoding enzymes responsible for biosynthesis, modification and degradation of glycerolipids were identified by mining a time-course global RNA-seq data set. It suggested that reduction in lipid contents under nitrogen deprivation is not attributable to the retarded biosynthesis processes, at least at the gene expression level, as most genes involved in their biosynthesis were unaffected by nitrogen supply, yet several genes were significantly up-regulated. Additionally, a conceptual eicosapentaenoic acid (EPA biosynthesis network is proposed based on the lipidomic and transcriptomic data, which underlined import of EPA from cytosolic glycerolipids to the plastid for synthesizing EPA-containing chloroplast membrane lipids.

  14. RNAi-based targeted gene knockdown in the model oleaginous microalgae Nannochloropsis oceanica.

    Science.gov (United States)

    Wei, Li; Xin, Yi; Wang, Qintao; Yang, Juan; Hu, Hanhua; Xu, Jian

    2017-03-01

    Microalgae are promising feedstock for renewable fuels such as biodiesel, yet development of industrial oleaginous strains has been hindered by the paucity and inefficiency of reverse genetics tools. Here we established an efficient RNAi-based targeted gene-knockdown method for Nannochloropsis spp., which are emerging model organisms for industrial microalgal oil production. The method achieved a 40-80% success rate in Nannochloropsis oceanica strain IMET1. When transcript level of one carbonic anhydrase (CA) was inhibited by 62-83% via RNAi, mutant cells exhibited photosynthetic oxygen evolution (POE) rates that were 68-100% higher than wild-type (WT) at pH 6.0, equivalent to WT at pH 8.2, yet 39-45% lower than WT at pH 9.0. Moreover, the mutant POE rates were negatively correlated with the increase of culture pH, an exact opposite of WT. Thus, a dynamic carbon concentration mechanism (CCM) that is highly sensitive to pH homeostasis was revealed, where the CA inhibition likely partially abrogated the mechanism that normally deactivates CCM under a high level of dissolved CO 2 . Extension of the method to another sequenced N. oceanica strain of CCMP 1779 demonstrated comparable performance. Finally, McrBC-PCR followed by bisulfite sequencing revealed that the gene knockdown is mediated by the CG, CHG and CHH types of DNA methylation at the coding region of the targeted gene. The efficiency, robustness and general applicability of this reverse genetics approach suggested the possibility of large-scale RNAi-based gene function screening in industrial microalgae. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  15. Acclimation to different depths by the marine angiosperm Posidonia oceanica: transcriptomic and proteomic profiles

    Directory of Open Access Journals (Sweden)

    Emanuela eDattolo

    2013-06-01

    Full Text Available For seagrasses, seasonal and daily variations in light and temperature represent the mains factors driving their distribution along the bathymetric cline. Changes in these environmental factors, due to climatic and anthropogenic effects, can compromise their survival. In a framework of conservation and restoration, it becomes crucial to improve our knowledge about the physiological plasticity of seagrass species along environmental gradients. Here, we aimed to identify differences in transcriptomic and proteomic profiles, involved in the acclimation along the depth gradient in the seagrass Posidonia oceanica, and to improve the available molecular resources in this species, which is an important requisite for the application of eco-genomic approaches. To do that, from plant growing in the shallow (-5m and a deep (-25m portions of a single meadow, (i we generated two reciprocal EST (Expressed Sequences Tags libraries using a Suppressive Subtractive Hybridization (SSH approach, to obtain depth/specific transcriptional profiles, and (ii we identified proteins differentially expressed, using the highly innovative USIS mass spectrometry methodology, coupled with 1D-SDS electrophoresis and labeling free approach. Mass spectra were searched in the open source Global Proteome Machine (GPM engine against plant databases and with the X!Tandem algorithm against a local database. Transcriptional analysis showed both quantitative and qualitative differences between depths. EST libraries had only the 3% of transcripts in common. A total of 315 peptides belonging to 64 proteins were identified by mass spectrometry. ATP synthase subunits were among the most abundant proteins in both conditions. Both approaches identified genes and proteins in pathways related to energy metabolism, transport and genetic information processing, that appear o be the most involved in depth acclimation in P. oceanica. Their putative rules in acclimation to depth were discussed.

  16. Acclimation to different depths by the marine angiosperm Posidonia oceanica: transcriptomic and proteomic profiles

    Science.gov (United States)

    Dattolo, Emanuela; Gu, Jenny; Bayer, Philipp E.; Mazzuca, Silvia; Serra, Ilia A.; Spadafora, Antonia; Bernardo, Letizia; Natali, Lucia; Cavallini, Andrea; Procaccini, Gabriele

    2013-01-01

    For seagrasses, seasonal and daily variations in light and temperature represent the mains factors driving their distribution along the bathymetric cline. Changes in these environmental factors, due to climatic and anthropogenic effects, can compromise their survival. In a framework of conservation and restoration, it becomes crucial to improve our knowledge about the physiological plasticity of seagrass species along environmental gradients. Here, we aimed to identify differences in transcriptomic and proteomic profiles, involved in the acclimation along the depth gradient in the seagrass Posidonia oceanica, and to improve the available molecular resources in this species, which is an important requisite for the application of eco-genomic approaches. To do that, from plant growing in shallow (−5 m) and deep (−25 m) portions of a single meadow, (i) we generated two reciprocal Expressed Sequences Tags (EST) libraries using a Suppressive Subtractive Hybridization (SSH) approach, to obtain depth/specific transcriptional profiles, and (ii) we identified proteins differentially expressed, using the highly innovative USIS mass spectrometry methodology, coupled with 1D-SDS electrophoresis and labeling free approach. Mass spectra were searched in the open source Global Proteome Machine (GPM) engine against plant databases and with the X!Tandem algorithm against a local database. Transcriptional analysis showed both quantitative and qualitative differences between depths. EST libraries had only the 3% of transcripts in common. A total of 315 peptides belonging to 64 proteins were identified by mass spectrometry. ATP synthase subunits were among the most abundant proteins in both conditions. Both approaches identified genes and proteins in pathways related to energy metabolism, transport and genetic information processing, that appear to be the most involved in depth acclimation in P. oceanica. Their putative rules in acclimation to depth were discussed. PMID:23785376

  17. Aeolian transport of seagrass ( Posidonia oceanica ) beach-cast to terrestrial systems

    KAUST Repository

    Jiménez, Maria A.

    2017-06-29

    The annual export of the Mediterranean seagrass (Posidonia oceanica) litter to adjacent beaches and coastal dunes was quantified by examining the fortnight evolution of seagrass beach-cast volume on two beaches in the NW Mediterranean (Son Real and Es Trenc, Mallorca Island, Spain) for two years and analyzing the wind speed and direction obtained from the closest Meteorological Spanish Agency surface weather stations. The decomposition stage of the deposits was examined by analyzing the total hydrolysable amino acids, its percentage distribution and derived degradation indexes. Prevalent winds exceeding 6 m s−1, the coastline morphology and type of terrestrial vegetation determine the annual dynamics of the seagrass beach-cast. In the most protected beach (Son Real) the seagrass beach-cast remained nearly stationary during the two studied years while it exhibited wide annual fluctuations in the less protected one (Es Trenc). The amounts of P. oceanica wrack washed on Son Real and Es Trenc beaches, respectively, were estimated at 309 kg DW m coastline−1 yr−1 and 1359 kg DW m coastline−1 yr−1. They supplied between 20 kg CaCO3 m coastline−1 yr−1 and 47 kg CaCO3 m coastline−1 yr−1. Between 54% (Son Real) and 70% (Es Trenc) of seagrass beach-cast, respectively accounting for 1.5 kg N m coastline−1 yr−1 and 8.6 kg N m coastline−1 yr−1, were annually exported from the beaches to adjacent dune systems. Our results reveal that Mediterranean seagrass meadows might be an important source of materials, including sand and nutrients, for adjacent terrestrial systems, able to support their functioning.

  18. Improved aqueous extraction of microalgal lipid by combined enzymatic and thermal lysis from wet biomass of Nannochloropsis oceanica.

    Science.gov (United States)

    Chen, Lin; Li, Runzhi; Ren, Xiaoli; Liu, Tianzhong

    2016-08-01

    High moisture content in wet algal biomass hinders effective performance of current lipid extraction methods. An improved aqueous extraction method combing thermal and enzymatic lysis was proposed and performed in algal slurry of Nannochloropsis oceanica (96.0% moisture) in this study. In general, cell-wall of N. oceanica was disrupted via thermal lysis and enzymatic lysis and lipid extraction was performed using aqueous surfactant solution. At the optimal conditions, high extraction efficiencies for both lipid (88.3%) and protein (62.4%) were obtained, which were significantly higher than those of traditional hexane extraction and other methods for wet algal biomass. Furthermore, an excessive extraction of polar lipid was found for wet biomass compared with dry biomass. The advantage of this method is to efficiently extract lipids from high moisture content algal biomass and avoid using organic solvent, indicating immense potential for commercial microalgae-based biofuel production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Effect of environmental factors (wave exposure and depth) and anthropogenic pressure in the C sink capacity of Posidonia oceanica meadows

    KAUST Repository

    Mazarrasa, Inés

    2017-03-20

    Seagrass are among the most important natural carbon sinks on Earth with Posidonia oceanica (Mediterranean Sea) considered as the most relevant species. Yet, the number of direct measurements of organic carbon burial rates in P. oceanica is still scarce and the effect of local environmental factors remains largely unexplored. In addition, P. oceanica meadows are declining due to the increase in anthropogenic pressure in coastal areas during the last century. The aim of this study is to assess the recent carbon sink capacity of P. oceanica and particularly the effect of human pressure and two environmental factors, water depth and exposure to wave energy (based on a fetch index), on the carbon burial rate since 1900. We conducted an extensive survey of sediment cores in meadows distributed across a gradient of depth, fetch, and human pressure around The Balearic Islands. Sediment and carbon accumulation rates were obtained from 210Pb concentrations profiles. Top-30 centimeters carbon stocks (6.1 ± 1.4 kg C m−2) and burial rates (26 ± 6 g C m−2 yr1) varied up to fivefold across meadows. No significant effect of water depth in carbon burial rates was observed. Although fetch was significantly correlated with sediment mean grain size, confirming the effect of wave exposure in the patterns of sedimentation, fetch alone could not explain the differences in carbon burial rates among the meadows examined. Human pressure affected carbon burial rates, leading to increased rates since the onset of the rise in anthropogenic pressure, particularly so in sheltered meadows supporting high human pressure.

  20. Improvement of Nannochloropsis oceanica growth performance through chemical mutation and characterization of fast growth physiology by transcriptome profiling

    Science.gov (United States)

    Liang, Sijie; Guo, Li; Lin, Genmei; Zhang, Zhongyi; Ding, Haiyan; Wang, Yamei; Yang, Guanpin

    2017-07-01

    Nannochloropsis oceanica promises to be an industrial-level producer of polyunsaturated fatty acids. In this study, the fastest and slowest growing N. oceanica mutants were selected through N-methyl-N'-nitro-N-nitrosoguanidine mutation, and two mutant strains and the wild type (WT) subjected to transcriptome profiling. It was found that the OD680 reads at stationary growth phase of both WT and its mutants were proportional to their cell density, thus indicating their division rate and growth speed during culture. This chemical mutation was effective for improving growth performance, and the fast strain divided faster by upregulating the expression of genes functioning in the cell cycle and downregulating genes involved in synthesis of amino acids, fatty acids, and sugars as well as the construction of ribosome and photosynthetic machinery. However, the relationship among the effected genes responsible for cell cycle, metabolism of fatty and amino acids, and construction of ribosome and photosynthetic machinery remained unclear. Further genetic studies are required for clarifying the genetic/metabolic networks underpinning the growth performance of N. oceanica. These findings demonstrated that this mutation strategy was effective for improving the growth performance of this species and explored a means of microalgal genetic improvement, particularly in species possessing a monoploid nucleus and asexual reproduction.

  1. Effects of Posidonia oceanica beach-cast on germination, growth and nutrient uptake of coastal dune plants.

    Directory of Open Access Journals (Sweden)

    Silvia Del Vecchio

    Full Text Available Seagrass meadows play an important role in marine ecosystems. A part of seagrass production is also exported to adjacent coastal terrestrial systems, possibly influencing their functioning. In this work we experimentally analyzed the effect of Posidonia oceanica beach-cast on plant germination, growth, and nutrient uptake of two plant species (Cakile maritima and Elymus farctus that grow on upper beaches and fore dunes along the Mediterranean coasts. We compared plants growing in simple sand (control with those growing in a substrate enriched with P. oceanica wrack (treatment in laboratory. P. oceanica wrack doubled the N substrate pool and kept the substrate humid. Plants growing in the treated substrate grew faster, were twice as large as those growing in the control substrate, while tissues were enriched in N and P (Cakile by the 1.3 fold in N and 2.5 fold in P; Elymus by 1.5 fold in N and 2 fold in P. Our results suggest a positive effect of seagrass litter for the enhancing of dune species, highlighting its role for the conservation of coastal dune ecosystems.

  2. The use of banquettes of Posidonia oceanica as a source of fiber and minerals in ruminant nutrition. An observational study.

    Science.gov (United States)

    Castillo, C; Mantecón, A R; Sotillo, J; Benedito, J L; Abuelo, A; Gutiérrez, C; Hernández, J

    2014-10-01

    In the search for new food sources that contribute to the optimization of livestock production this paper discusses the possibility of using waste (called banquettes) of a marine plant commonly found on the Mediterranean coasts: Posidonia oceanica. The idea stems from the use of a waste that in summertime generates large costs because it is considered bothersome on the beaches. Thus, tons and tons of residues are collected each year from the beach, being destined for incineration. However, alternative uses for these residues are suggested, such as forage that is particularly relevant for the Mediterranean coast, where the weather does not support abundant grass growth. With this purpose, samples of banquettes of P. oceanica from six different points of a touristic place located in the Murcia Region (S.E. of Spain) were collected in April 2012 on the same day directly from the beach above the water line, washed with distilled water and sun-dried for 48 h. Approximately 500 g of each sample of plant material was chopped and two subsamples of 200 g each were placed in airtight plastic containers and sent to the laboratory for mineral and chemical analysis. This report provides data on the nutritional composition of P. oceanica such as mineral contents (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and chemical composition (ash, CP, ether extract (EE), NDF and ADF, respectively) and ADL. Finally, the in sacco rumen disappearance of dry matter (DM), organic matter (OM), CP and NDF were studied. Our results showed that minerals, except for Fe, where within the range of values reported for P. oceanica in other parts of the Mediterranean region. Given the high Fe content further studies assessing the antagonic Fe-Cu interaction and its effect on animal health should be addressed. In relation to chemical composition, it is clear that this seagrass is a poor protein source and has levels of DM degradability at 24 h, similar to those obtained for cereal straw. The information

  3. Molecular Characterization of CTR-type Copper Transporters in an Oceanic Diatom, Thalassiosira oceanica 1005

    Science.gov (United States)

    Kong, L.; Price, N. M.

    2016-02-01

    Copper is an essential micronutrient for phytoplankton growth because of its role as a redox cofactor in electron transfer proteins in photosynthesis and respiration, and a potentially limiting resource in parts of the open sea. Thalassiosira oceanica 1005 can grow at inorganic copper concentrations varying from 10 fmol/L to 10 nmol/L by regulating copper uptake across plasma membrane. Four putative CTR-type copper transporter genes (ToCTR1, ToCTR2, ToCTR3.1 and ToCTR3.2) were identified by BLASTP search against the T. oceanica genome. Predicted gene models were revised by assembled mRNA sequencing transcripts and updated gene models contained all conserved features of characterized CTR-type copper transporters. ToCTR3.1 and ToCTR3.2 may arise from one another by gene duplication as they shared a sequence similarity of 97.6% with a peptide insertion of 5 amino acids at N-terminus of ToCTR3.1. The expression of ToCTR1, ToCTR2 and ToCTR3.1/3.2 was upregulated in low copper concentrations, but only ToCTR3.1/3.2 showed a significant increase (2.5 fold) in copper-starved cells. Both ToCTR3.1 and ToCTR3.2 restored growth of a yeast double mutant, Saccharomyces cerevisiae ctr1Δctr3Δ, in copper deficient medium. GFP-fused ToCTR expression showed that some ToCTR3.1 localized to the plasma membrane but a large portion was retained in the endoplasmic reticulum. Inefficient targeting of ToCTR3.1 to the yeast outer membrane may explain poorer growth compared to the Saccharomyces native ScCTR1 transformant. Thus, diatom CTR genes encoding CTR-type copper transporters show high-affinity copper uptake and their regulation may enable diatoms to survive in ocean environments containing a wide range of copper concentrations.

  4. Variability in patterns of macro-epiphytic leaf community of Posidonia oceanica in the Islands of Kuriate: Western coast of Tunisia

    Directory of Open Access Journals (Sweden)

    Ben Brahim Mounir

    2016-03-01

    Full Text Available Objective: To test the response of the epiphyte community structure and biomass of the Posidonia oceanica (P. oceanica leaves to natural disturbance. Methods: Sampling of P. oceanica was carried in winter and summer on three sites in Kuriate Islands (western coast of Tunisia subject to different environments disturbances. Shoots of P. oceanica were preserved in seawater-formalin (5% solution for macro-epiphytes species identification in the laboratory. The samples were examined for leaf surface per shoot and the coverage (expressed as a percentage of leaf surface of each morphological group, then carefully scraped with a razor blade. Epiphytes and scraped leaves were oven-dried at 60 °C for 48 h. Biomass was expressed as g dry weight/shoot. Results: The biomass and the percentage cover of macro-epiphytic leaves showed seasonal variation. The highest values of epiphytic leaves were detected in summer whereas the lowest values were registered during winter. ANOVA showed that Kuriate Islands functioned as a single ecosystem in terms assemblage of macro-epiphytic leaves since no significant variation was detected for biomass and percentage cover at the scale site. Our study showed that natural disturbance had no effect on the assemblage distribution and the biomass of macro-epiphyte on the leaves of P. oceanica between the scales of site, whereas variability at the smallest scale was detected. ANOVA showed that exposure to wind and current had no effect on the biomass of macro-epiphytes leaves. Conclusions: Biomass and assemblages of macro-epiphytic leaves of P. oceanica were high in summer and homogenous between all sites investigated. Natural disturbances such as exposure to wind have no effect on the distribution and the biomass of epiphytes on the shallow meadow.

  5. A type 2 diacylglycerol acyltransferase accelerates the triacylglycerol biosynthesis in heterokont oleaginous microalga Nannochloropsis oceanica.

    Science.gov (United States)

    Li, Da-Wei; Cen, Shi-Ying; Liu, Yu-Hong; Balamurugan, Srinivasan; Zheng, Xin-Yan; Alimujiang, Adili; Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye

    2016-07-10

    Oleaginous microalgae have received a considerable attention as potential biofuel feedstock. However, lack of industry-suitable strain with lipid rich biomass limits its commercial applications. Targeted engineering of lipogenic pathways represents a promising strategy to enhance the efficacy of microalgal oil production. In this study, a type 2 diacylglycerol acyltransferase (DGAT), a rate-limiting enzyme in triacylglycerol (TAG) biosynthesis, was identified and overexpressed in heterokont oleaginous microalga Nannochloropsis oceanica for the first time. Overexpression of DGAT2 in Nannochloropsis increased the relative transcript abundance by 3.48-fold in engineered microalgae cells. TAG biosynthesis was subsequently accelerated by DGAT2 overexpression and neutral lipid content was significantly elevated by 69% in engineered microalgae. The fatty acid profile determined by GC-MS revealed that fatty acid composition was altered in engineered microalgae. Saturated fatty acids and polyunsaturated fatty acids were found to be increased whereas monounsaturated fatty acids content decreased. Furthermore, DGAT2 overexpression did not show negative impact on algal growth parameters. The present investigation showed that the identified DGAT2 would be a potential candidate for enhancing TAG biosynthesis and might facilitate the development of promising oleaginous strains with industrial potential. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Cultivation of Nannochloropsis oceanica biomass rich in eicosapentaenoic acid utilizing wastewater as nutrient resource.

    Science.gov (United States)

    Mitra, Madhusree; Shah, Freny; Bharadwaj, S V Vamsi; Patidar, Shailesh Kumar; Mishra, Sandhya

    2016-10-01

    The eicosapentaenoic acid rich marine eustigmatophyte Nannochloropsis oceanica was grown in wastewaters sampled from four different industries (i.e. pesticides industry, pharmaceutical industry, activated sludge treatment plant of municipality sewage and petroleum (oil) industry). Under the wastewater based growth conditions used in this study, the biomass productivity ranged from 21.78±0.87 to 27.78±0.22mgL(-1)d(-1) in relation to freeze dried biomass, while the lipid productivity varied between 5.59±0.02 and 6.81±0.04mgL(-1)d(-1). Although comparatively higher biomass, lipid and EPA productivity was observed in Conway medium, the %EPA content was similarly observed in pesticides industry and municipal effluents. The results highlight the possibility of selectively using wastewater as a growth medium, demonstrating the elevated eicosapentaenoic acid content and biodiesel properties, that complies with the European standards for biodiesel. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The plastoquinone pool of Nannochloropsis oceanica is not completely reduced during bright light pulses.

    Science.gov (United States)

    Røkke, Gunvor; Melø, Thor Bernt; Hohmann-Marriott, Martin Frank

    2017-01-01

    The lipid-producing model alga Nannochloropsis oceanica has a distinct photosynthetic machinery. This organism possesses chlorophyll a as its only chlorophyll species, and has a high ratio of PSI to PSII. This high ratio of PSI to PSII may affect the redox state of the plastoquinone pool during exposure to light, and consequently may play a role in activating photoprotection mechanisms. We utilized pulse-amplitude modulated fluorometry to investigate the redox state of the plastoquinone pool during and after bright light pulses. Our data indicate that even very intense (5910 μmol photons s-1m-2 of blue light having a wavelength of 440 nm) light pulses of 0.8 second duration are not sufficient to completely reduce the plastoquinone pool in Nannochloropsis. In order to achieve extensive reduction of the plastoquinone pool by bright light pulses, anaerobic conditions or an inhibitor of the photosynthetic electron transport chain has to be utilized. The implication of this finding for the application of the widely used saturating pulse method in algae is discussed.

  8. Discards of the commercial boat seine fisheries on Posidonia oceanica beds in the eastern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Perica Cetinić

    2011-06-01

    Full Text Available Scientific observer records were used to estimate the retained and discarded catch composition of the commercial boat seine fisheries over Posidonia oceanica (Linnaeus Delile meadows in the eastern Adriatic, from November 2008 to December 2009. A total of 91 fish and cephalopod species were recorded in the catches, of which 20 species were always retained, 40 were always discarded and the remaining 31 were selected depending on size (only larger specimens were retained. The most abundant species in the retained catch were Spicara smaris, Atherina hepsetus and Mullus barbatus, while Chromis chromis, Symphodus ocellatus and small specimens of Boops boops dominated the discards. An estimated 43.5% by number and 28.5% by weight of the total catch were discarded. Since the minimum landing size (MLS is regulated for only 4 out of the 15 most important species in this study, and even these regulations are only partially followed, discarding practices were generally market-driven. The retained and discarded amounts of the catch as well as the numbers of retained and discarded species showed a seasonal pattern. The catches recorded during summer/autumn were generally larger than those in winter/spring. High rates of immature specimens were observed for the most important species, which is probably related to the role of Posidonia beds as important nursery grounds.

  9. Influence of microhabitat on seedling survival and growth of the mediterranean seagrass posidonia oceanica (l.) Delile

    Science.gov (United States)

    Alagna, Adriana; Fernández, Tomás Vega; Terlizzi, Antonio; Badalamenti, Fabio

    2013-03-01

    Early life history phases are crucial stages limiting species distribution and abundance, thus influencing assemblage composition in marine benthic environments. In seagrass systems the period between seed germination and establishment is one of the most vulnerable phases for plant development. This study analyzes the influence of microhabitat structure, in terms of substrate nature and algal canopy, on the persistence and growth over two years of seedlings of Posidonia oceanica, the dominant Mediterranean seagrass. Long time persistence of seedlings only occurred on microhabitats providing vegetated rocky substrates, with a maximum value of 81% on rock covered by Cystoseira spp. No seedling was found on unvegetated sand and gravel after the first year. Seedling growth resulted increased on rock covered by Halopteris spp. and Dilophus spp. than on rock covered by Cystoseira spp. Results suggest that high canopy onto a stable substrate enhances seedling persistence, probably because these allow the best anchorage by roots while hampering water flow. In contrast, turf algal cover promotes better seedling growth, possibly through higher light irradiance and nutrient availability. Our findings support the view that the understanding of the factors controlling early life processes is a necessary prerequisite for the comprehension of seagrass species distribution patterns, colonization and recovery potentials, which, in turn, can guide sound strategies for seagrass management and restoration.

  10. Dynamic of Posidonia oceanica seagrass meadows in the northwestern Mediterranean: Could climate change be to blame?

    Science.gov (United States)

    Pergent, Gérard; Pergent-Martini, Christine; Bein, Aymeric; Dedeken, Marine; Oberti, Pascal; Orsini, Antoine; Santucci, Jean-François; Short, Frederic

    2015-07-01

    The distribution and the vitality of the P. oceanica meadow were monitored in the western Mediterranean at 15 sites along the coasts of Corsica (1000 km of coastline) using two monitoring systems, the Posidonia Monitoring Network and SeagrassNet, between 2004 and 2013. While the vitality of the meadow is satisfactory overall, due to the low impact of human pressure along these coasts, patterns of change over time show a slight degradation of the main descriptors of the meadow. The meadow's vitality index had declined on average by 8.6%, the BiPo index by 9.8%, and there was a regression of the lower limit at six sites. While this pattern of change may reflect local alterations in the environment (increase or decline in human pressure), the regressive dynamic of the meadow observed at the lower limit at several reference sites (e.g., Marine Protected Areas, sites distant from sources of human impact) is more worrying. Two hypotheses might explain the regression observed: (i) the rise in mean sea level during the study period, which may have resulted in a significant regression in sectors where the slope is relatively slight, and (ii) the North Atlantic Oscillation (NAO), which declined from 2002 to reach very low values in 2010. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  11. Microwave-assisted extraction and pharmacological evaluation of polysaccharides from Posidonia oceanica.

    Science.gov (United States)

    Ben Salem, Yosra; Abdelhamid, Amal; Mkadmini Hammi, Khaoula; Le Cerf, Didier; Bouraoui, Abderrahman; Majdoub, Hatem

    2017-10-01

    Microwave-assisted extraction was employed for the isolation of polysaccharides from Posidonia oceanica (PPO). The extracting parameters were optimized adopting response surface methodology. The highest polysaccharide yield (2.55 ± 0.09%), which is in concordance with the predicted value (2.76%), was obtained under the following conditions: extraction time 60 s, liquid-solid ratio of 50:1 (mL/g) and power of 800 W. This polysaccharide, with molecular weight of 524 KDa, characterized by gas chromatography-mass spectrometry showed that PPO was mainly composed of galactose, glucose, and arabinose with molar percentages 25.38, 24.37, and 21.64%, respectively. The pharmacological evaluation of PPO using animal models at the dose of 100 mg/kg indicated a significant anti-inflammatory activity with a percentage of inhibition of edema of 54.65% and a significant antinociceptive activity with 78.91% inhibition of writhing for peripheral analgesic activity and an increase in the hot plate reaction time for central analgesic activity.

  12. Seagrass (Posidonia oceanica) seedlings in a high-CO2 world: from physiology to herbivory

    KAUST Repository

    Hernán, Gema

    2016-12-01

    Under future increased CO2 concentrations, seagrasses are predicted to perform better as a result of increased photosynthesis, but the effects in carbon balance and growth are unclear and remain unexplored for early life stages such as seedlings, which allow plant dispersal and provide the potential for adaptation under changing environmental conditions. Furthermore, the outcome of the concomitant biochemical changes in plant-herbivore interactions has been poorly studied, yet may have important implications in plant communities. In this study we determined the effects of experimental exposure to current and future predicted CO2 concentrations on the physiology, size and defense strategies against herbivory in the earliest life stage of the Mediterranean seagrass Posidonia oceanica. The photosynthetic performance of seedlings, assessed by fluorescence, improved under increased pCO2 conditions after 60 days, although these differences disappeared after 90 days. Furthermore, these plants exhibited bigger seeds and higher carbon storage in belowground tissues, having thus more resources to tolerate and recover from stressors. Of the several herbivory resistance traits measured, plants under high pCO2 conditions had a lower leaf N content but higher sucrose. These seedlings were preferred by herbivorous sea urchins in feeding trials, which could potentially counteract some of the positive effects observed.

  13. Contrasting effects of copper limitation on the photosynthetic apparatus in two strains of the open ocean diatom Thalassiosira oceanica.

    Directory of Open Access Journals (Sweden)

    Anna A Hippmann

    Full Text Available There is an intricate interaction between iron (Fe and copper (Cu physiology in diatoms. However, strategies to cope with low Cu are largely unknown. This study unveils the comprehensive restructuring of the photosynthetic apparatus in the diatom Thalassiosira oceanica (CCMP1003 in response to low Cu, at the physiological and proteomic level. The restructuring results in a shift from light harvesting for photochemistry-and ultimately for carbon fixation-to photoprotection, reducing carbon fixation and oxygen evolution. The observed decreases in the physiological parameters Fv/Fm, carbon fixation, and oxygen evolution, concomitant with increases in the antennae absorption cross section (σPSII, non-photochemical quenching (NPQ and the conversion factor (φe:C/ηPSII are in agreement with well documented cellular responses to low Fe. However, the underlying proteomic changes due to low Cu are very different from those elicited by low Fe. Low Cu induces a significant four-fold reduction in the Cu-containing photosynthetic electron carrier plastocyanin. The decrease in plastocyanin causes a bottleneck within the photosynthetic electron transport chain (ETC, ultimately leading to substantial stoichiometric changes. Namely, 2-fold reduction in both cytochrome b6f complex (cytb6f and photosystem II (PSII, no change in the Fe-rich PSI and a 40- and 2-fold increase in proteins potentially involved in detoxification of reactive oxygen species (ferredoxin and ferredoxin:NADP+ reductase, respectively. Furthermore, we identify 48 light harvesting complex (LHC proteins in the publicly available genome of T. oceanica and provide proteomic evidence for 33 of these. The change in the LHC composition within the antennae in response to low Cu underlines the shift from photochemistry to photoprotection in T. oceanica (CCMP1003. Interestingly, we also reveal very significant intra-specific strain differences. Another strain of T. oceanica (CCMP 1005 requires

  14. Collaboration between research institutions and Marine Protected Area contributes to Posidonia oceanica conservation: The Egadi Island’s experiment

    International Nuclear Information System (INIS)

    Cocito, Silvia; Lombardi, Chiara; Peirano, Andrea; Donati, Stefano; Patti Genovese, Pietro; Ponzè, Niccolo

    2015-01-01

    Preliminary results on the collaboration between the ENEA’s Marine Environment Research Center and the Egadi Islands’ Marine Protected Area (MPA), aimed to evaluate effectiveness of artificial reefs in limiting the impact of trawling on Posidonia oceanica meadow at Favignana Island, are reported. The methods and parameters chosen for monitoring showed their reliability in training non-experienced personnel for data collection within the MPA. The proposed monitoring approach is of great value to the MPA interested in both gathering basic and long-term data on the health status of protected habitats and acquiring baseline information useful for the evaluation of protection and conservation actions. [it

  15. Lipidomic analysis can distinguish between two morphologically similar strains of Nannochloropsis oceanica.

    Science.gov (United States)

    Li, Shuang; Xu, Jilin; Jiang, Ying; Zhou, Chengxu; Yu, Xuejun; Zhong, Yingying; Chen, Juanjuan; Yan, Xiaojun

    2015-04-01

    The two morphologically similar microalgae NMBluh014 and NMBluh-X belong to two different strains of Nannochloropsis oceanica. They possess obviously different feeding effects on bivalves, but are indistinguishable by 18S rRNA and morphological features. In this work, lipidomic analysis followed by principal component analysis and orthogonal projections to latent structures discriminant analysis provided a clear distinction between these strains. Metabolites that definitively contribute to the classification were selected as potential biomarkers. The most important difference in polar lipids were sulfoquinovosyldiacylglycerol (containing 18:1/16:0 and 18:3/16:0) and monogalactosyldiacylglycerol (containing 18:3/16:3 and 20:5/14:0), which were detected only in NMBluh-X. Additionally, an exhaustive qualitative and quantitative profiling of the neutral lipid triacylglycerol (TAG) in the two strains was carried out. The predominant species of TAG containing 16:1/16:1/16:1 acyl groups was detected only in NMBluh-X with a content of ~93.67 ± 11.85 nmol · mg(-1) dry algae at the onset of stationary phase. Meanwhile, TAG containing 16:0/16:0/16:0 was the main TAG in NMBluh014 with a content of 40.25 ± 3.92 nmol · mg(-1) . These results provided the most straightforward evidence for differentiating the two species. The metabolomic profiling indicated that NMBluh-X underwent significant chemical and physiological changes during the growth process, whereas NMBluh014 did not show such noticeable time-dependent metabolite change. This study is the first using Ultra Performance Liquid Chromatography coupled with Electrospray ionization-Quadrupole-Time of Flight Mass Spectrometry (UPLC-Q-TOF-MS) for lipidomic profiling with multivariate statistical analysis to explore lipidomic differences of plesiomorphous microalgae. Our results demonstrate that lipidomic profiling is a valid chemotaxonomic tool in the study of microalgal systematics. © 2015 Phycological Society of America.

  16. Epiphyte load on the seagrass Posidonia oceanica (L. Delile does not indicate anthropogenic nutrient loading in Cabrera Archipelago National Park (Balearic Islands, Western Mediterranean

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    Jorge Terrados

    2008-09-01

    Full Text Available The epiphyte load on the leaves of the seagrass Posidonia oceanica (L. Delile was estimated at the end of summer in three sites and two depths (7 m and 17 m of the Cabrera Archipelago National Park (Balearic Islands, Western Mediterranean from 2004 to 2006 to evaluate if epiphyte load could be used as an indicator of anthropogenic nutrient loading in the shallow marine ecosystems of the park. Asymmetrical ANOVA was used to divide data variability into two components: the contrast between the site receiving direct anthropogenic inputs of nutrients and organic matter (Es Port and the two control sites (Cala Santa María, Es Burri; and the variability between the control sites. The nitrogen concentration in P. oceanica leaves was higher in Es Port than in Cala Santa María and Es Burri but only at 7 m depth. There was no difference between the epiphyte load on P. oceanica shoots in Es Port and the sites without inputs at both 7 m and 17 m. However, the epiphyte load in Es Burri was higher than that in Cala Santa María at both depths. The results show that the epiphyte load on P. oceanica shoots was not a sensitive indicator of anthropogenic nutrient and organic matter loading in Cabrera Archipelago National Park.

  17. The characteristics of TAG and EPA accumulation in Nannochloropsis oceanica IMET1 under different nitrogen supply regimes.

    Science.gov (United States)

    Meng, Yingying; Jiang, Junpeng; Wang, Haitao; Cao, Xupeng; Xue, Song; Yang, Qing; Wang, Weiliang

    2015-03-01

    The strategy of nitrogen limitation has been widely applied to enhance lipid production in microalgae. The changes of cellular composition, and the characteristics of triacylglycerol (TAG) and eicosapentaenoic acid (EPA) accumulation in Nannochloropsis oceanica IMET1 were investigated. The results revealed that after nitrogen limitation TAG rather than carbohydrate was the dominant carbon sink in N. oceanica IMET1. Different nitrogen supplementation strategies were applied in order to achieve high TAG and EPA productivity, respectively. Limited nitrogen was supplied to improve TAG production, and a maximum productivity of 29.44 mg L(-1) d(-1) was obtained, which was a 6.74-fold increase compared to nitrogen-depleted cultivation. The highest EPA productivity of 7.66 mg L(-1) d(-1) was achieved under nitrogen-replete cultivation, which is different from the condition for TAG maximum productivity because the EPA is in glycolipids and phospholipids mainly. The fatty acid composition analysis identified the source of acyl group in TAG accumulation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Nontransgenic Marker-Free Gene Disruption by an Episomal CRISPR System in the Oleaginous Microalga, Nannochloropsis oceanica CCMP1779.

    Science.gov (United States)

    Poliner, Eric; Takeuchi, Tomomi; Du, Zhi-Yan; Benning, Christoph; Farré, Eva M

    2018-03-14

    Utilization of microalgae has been hampered by limited tools for creating loss-of-function mutants. Furthermore, modified strains for deployment into the field must be free of antibiotic resistance genes and face fewer regulatory hurdles if they are transgene free. The oleaginous microalga, Nannochloropsis oceanica CCMP1779, is an emerging model for microalgal lipid metabolism. We present a one-vector episomal CRISPR/Cas9 system for N. oceanica that enables the generation of marker-free mutant lines. The CEN/ARS6 region from Saccharomyces cerevisiae was included in the vector to facilitate its maintenance as circular extrachromosal DNA. The vector utilizes a bidirectional promoter to produce both Cas9 and a ribozyme flanked sgRNA. This system efficiently generates targeted mutations, and allows the loss of episomal DNA after the removal of selection pressure, resulting in marker-free nontransgenic engineered lines. To test this system, we disrupted the nitrate reductase gene ( NR) and subsequently removed the CRISPR episome to generate nontransgenic marker-free nitrate reductase knockout lines (NR-KO).

  19. Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery1[C][W][OA

    Science.gov (United States)

    Dong, Hong-Po; Williams, Ernest; Wang, Da-zhi; Xie, Zhang-Xian; Hsia, Ru-ching; Jenck, Alizée; Halden, Rolf; Li, Jing; Chen, Feng; Place, Allen R.

    2013-01-01

    The Nannochloropsis genus contains oleaginous microalgae that have served as model systems for developing renewable biodiesel. Recent genomic and transcriptomic studies on Nannochloropsis species have provided insights into the regulation of lipid production in response to nitrogen stress. Previous studies have focused on the responses of Nannochloropsis species to short-term nitrogen stress, but the effect of long-term nitrogen deprivation remains largely unknown. In this study, physiological and proteomic approaches were combined to understand the mechanisms by which Nannochloropsis oceanica IMET1 is able to endure long-term nitrate deprivation and its ability to recover homeostasis when nitrogen is amended. Changes of the proteome during chronic nitrogen starvation espoused the physiological changes observed, and there was a general trend toward recycling nitrogen and storage of lipids. This was evidenced by a global down-regulation of protein expression, a retained expression of proteins involved in glycolysis and the synthesis of fatty acids, as well as an up-regulation of enzymes used in nitrogen scavenging and protein turnover. Also, lipid accumulation and autophagy of plastids may play a key role in maintaining cell vitality. Following the addition of nitrogen, there were proteomic changes and metabolic changes observed within 24 h, which resulted in a return of the culture to steady state within 4 d. These results demonstrate the ability of N. oceanica IMET1 to recover from long periods of nitrate deprivation without apparent detriment to the culture and provide proteomic markers for genetic modification. PMID:23637339

  20. Regulation of the cholesterol biosynthetic pathway and its integration with fatty acid biosynthesis in the oleaginous microalga Nannochloropsis oceanica

    Science.gov (United States)

    2014-01-01

    Background Sterols are vital structural and regulatory components in eukaryotic cells; however, their biosynthetic pathways and functional roles in microalgae remain poorly understood. Results In the oleaginous microalga Nannochloropsis oceanica, the sterol biosynthetic pathway produces phytosterols as minor products and cholesterol as the major product. The evidence together with their deduced biosynthetic pathways suggests that N. oceanica exhibits features of both higher plants and mammals. Temporal tracking of sterol profiles and sterol-biosynthetic transcripts in response to changes in light intensity and nitrogen supply reveal that sterols play roles in cell proliferation, chloroplast differentiation, and photosynthesis. Furthermore, the dynamics of fatty acid (FA) and FA-biosynthetic transcripts upon chemical inhibitor-induced sterol depletion reveal possible co-regulation of sterol production and FA synthesis, in that the squalene epoxidase inhibitor terbinafine reduces sterol content yet significantly elevates free FA production. Thus, a feedback regulation of sterol and FA homeostasis is proposed, with the 1-deoxy-D-xylulose 5-phosphate synthase (DXS, the committed enzyme in isoprenoid and sterol biosynthesis) gene potentially subject to feedback regulation by sterols. Conclusion These findings reveal features of sterol function and biosynthesis in microalgae and suggest new genetic engineering or chemical biology approaches for enhanced oil production in microalgae. PMID:24920959

  1. Eicosapentaenoic acid production from Nannochloropsis oceanica CY2 using deep sea water in outdoor plastic-bag type photobioreactors.

    Science.gov (United States)

    Chen, Chun-Yen; Nagarajan, Dillirani; Cheah, Wai Yan

    2018-04-01

    In this study, Nannochloropsis oceanica CY2 was grown in deep-sea water (DSW)-based medium in 5-L plastic bag-type photobioreactors (PBRs) for the autotrophic production of Eicosapentaenoic acid (EPA, 20:5n-3). EPA production of N. oceanica CY2 was stimulated when it was grown in 100% DSW amended with 1.5 g L -1 NaNO 3 , achieving a EPA content of 3.1% and a biomass concentration of 3.3 g L -1 . An outdoor-simulated microalgae cultivation system was also conducted to validate the feasibility of outdoor cultivation of the CY2 strain in plastic bag-type PBRs. Using an inoculum size of 0.6 g/L, the biomass concentration in the PBR culture was 3.5 g L -1 , while the EPA content and productivity reached a maximal level of 4.12% and 7.49 mg L -1  d -1 , respectively. When the PBRs were operated on semi-batch mode, the EPA productivity could further increase to 9.9 mg L -1  d -1 with a stable EPA content of 4.1%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Posidonia oceanica as a Renewable Lignocellulosic Biomass for the Synthesis of Cellulose Acetate and Glycidyl Methacrylate Grafted Cellulose

    Directory of Open Access Journals (Sweden)

    Elena Vismara

    2013-05-01

    Full Text Available High-grade cellulose (97% α-cellulose content of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H2O2 and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C. Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS of 0.72 was produced by quenching Fenton’s reagent (H2O2/FeSO4 generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p-nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

  3. Effects of recreational fishing on three fish species from the Posidonia oceanica meadows off Minorca (Balearic archipelago, western Mediterranean

    Directory of Open Access Journals (Sweden)

    Luis Cardona

    2007-12-01

    Full Text Available Experimental fishing and visual censuses were conducted at nine Posidonia oceanica sites off Minorca exposed to different levels of fishing intensity to assess the effects of recreational fishing on the species that dominate the catch. Total catch per unit effort (CPUE was highly seasonal and a statistically significant interaction term existed between the season and the level of fishing intensity. CPUE decreased everywhere at the end of the fishing season (autumn, but such a reduction was more intense at those sites exposed to the highest level of fishing. Visual censuses confirmed that there was a lower abundance of vulnerable fish in autumn. Differences vanished in spring probably because fish reshuffled between the considered sites throughout the winter, when the level of fishing intensity was extremely low. Although the average total lengths of Serranus scriba and Diplodus annularis were unaffected by the level of fishing intensity, the average total length of Coris julis was smaller at the most heavily fished sites. In conclusion, recreational fishing has a relevant impact on most of the exploited species and some of the seasonality reported for the Posidonia oceanica fish assemblages might be caused by the seasonality of the fishery.

  4. Implications of extreme life span in clonal organisms: millenary clones in meadows of the threatened seagrass Posidonia oceanica.

    Directory of Open Access Journals (Sweden)

    Sophie Arnaud-Haond

    Full Text Available The maximum size and age that clonal organisms can reach remains poorly known, although we do know that the largest natural clones can extend over hundreds or thousands of metres and potentially live for centuries. We made a review of findings to date, which reveal that the maximum clone age and size estimates reported in the literature are typically limited by the scale of sampling, and may grossly underestimate the maximum age and size of clonal organisms. A case study presented here shows the occurrence of clones of slow-growing marine angiosperm Posidonia oceanica at spatial scales ranging from metres to hundreds of kilometres, using microsatellites on 1544 sampling units from a total of 40 locations across the Mediterranean Sea. This analysis revealed the presence, with a prevalence of 3.5 to 8.9%, of very large clones spreading over one to several (up to 15 kilometres at the different locations. Using estimates from field studies and models of the clonal growth of P. oceanica, we estimated these large clones to be hundreds to thousands of years old, suggesting the evolution of general purpose genotypes with large phenotypic plasticity in this species. These results, obtained combining genetics, demography and model-based calculations, question present knowledge and understanding of the spreading capacity and life span of plant clones. These findings call for further research on these life history traits associated with clonality, considering their possible ecological and evolutionary implications.

  5. Depth-specific fluctuations of gene expression and protein abundance modulate the photophysiology in the seagrass Posidonia oceanica

    Science.gov (United States)

    Procaccini, Gabriele; Ruocco, Miriam; Marín-Guirao, Lázaro; Dattolo, Emanuela; Brunet, Christophe; D'Esposito, Daniela; Lauritano, Chiara; Mazzuca, Silvia; Serra, Ilia Anna; Bernardo, Letizia; Piro, Amalia; Beer, Sven; Björk, Mats; Gullström, Martin; Buapet, Pimchanok; Rasmusson, Lina M.; Felisberto, Paulo; Gobert, Sylvie; Runcie, John W.; Silva, João; Olivé, Irene; Costa, Monya M.; Barrote, Isabel; Santos, Rui

    2017-02-01

    Here we present the results of a multiple organizational level analysis conceived to identify acclimative/adaptive strategies exhibited by the seagrass Posidonia oceanica to the daily fluctuations in the light environment, at contrasting depths. We assessed changes in photophysiological parameters, leaf respiration, pigments, and protein and mRNA expression levels. The results show that the diel oscillations of P. oceanica photophysiological and respiratory responses were related to transcripts and proteins expression of the genes involved in those processes and that there was a response asynchrony between shallow and deep plants probably caused by the strong differences in the light environment. The photochemical pathway of energy use was more effective in shallow plants due to higher light availability, but these plants needed more investment in photoprotection and photorepair, requiring higher translation and protein synthesis than deep plants. The genetic differentiation between deep and shallow stands suggests the existence of locally adapted genotypes to contrasting light environments. The depth-specific diel rhythms of photosynthetic and respiratory processes, from molecular to physiological levels, must be considered in the management and conservation of these key coastal ecosystems.

  6. A type-I diacylglycerol acyltransferase modulates triacylglycerol biosynthesis and fatty acid composition in the oleaginous microalga, Nannochloropsis oceanica.

    Science.gov (United States)

    Wei, Hehong; Shi, Ying; Ma, Xiaonian; Pan, Yufang; Hu, Hanhua; Li, Yantao; Luo, Ming; Gerken, Henri; Liu, Jin

    2017-01-01

    Photosynthetic oleaginous microalgae are considered promising feedstocks for biofuels. The marine microalga, Nannochloropsis oceanica, has been attracting ever-increasing interest because of its fast growth, high triacylglycerol (TAG) content, and available genome sequence and genetic tools. Diacylglycerol acyltransferase (DGAT) catalyzes the last and committed step of TAG biosynthesis in the acyl-CoA-dependent pathway. Previous studies have identified 13 putative DGAT-encoding genes in the genome of N. oceanica , but the functional role of DGAT genes, especially type-I DGAT ( DGAT1 ), remains ambiguous. Nannochloropsis oceanica IMET1 possesses two DGAT1 genes: NoDGAT1A and NoDGAT1B . Functional complementation demonstrated the capability of NoDGAT1A rather than NoDGAT1B to restore TAG synthesis in a TAG-deficient yeast strain. In vitro DGAT assays revealed that NoDGAT1A preferred saturated/monounsaturated acyl-CoAs and eukaryotic diacylglycerols (DAGs) for TAG synthesis, while NoDGAT1B had no detectable enzymatic activity. Assisted with green fluorescence protein (GFP) fusion, fluorescence microscopy analysis indicated the localization of NoDGAT1A in the chloroplast endoplasmic reticulum (cER) of N. oceanica . NoDGAT1A knockdown caused ~25% decline in TAG content upon nitrogen depletion, accompanied by the reduced C16:0, C18:0, and C18:1 in TAG sn -1/ sn -3 positions and C18:1 in the TAG sn -2 position. NoDGAT1A overexpression, on the other hand, led to ~39% increase in TAG content upon nitrogen depletion, accompanied by the enhanced C16:0 and C18:1 in the TAG sn -1/ sn -3 positions and C18:1 in the TAG sn -2 position. Interestingly, NoDGAT1A overexpression also promoted TAG accumulation (by ~2.4-fold) under nitrogen-replete conditions without compromising cell growth, and TAG yield of the overexpression line reached 0.49 g L -1 at the end of a 10-day batch culture, 47% greater than that of the control line. Taken together, our work demonstrates the

  7. A toolkit for Nannochloropsis oceanica CCMP1779 enables gene stacking and genetic engineering of the eicosapentaenoic acid pathway for enhanced long-chain polyunsaturated fatty acid production.

    Science.gov (United States)

    Poliner, Eric; Pulman, Jane A; Zienkiewicz, Krzysztof; Childs, Kevin; Benning, Christoph; Farré, Eva M

    2018-01-01

    Nannochloropsis oceanica is an oleaginous microalga rich in ω3 long-chain polyunsaturated fatty acids (LC-PUFAs) content, in the form of eicosapentaenoic acid (EPA). We identified the enzymes involved in LC-PUFA biosynthesis in N. oceanica CCMP1779 and generated multigene expression vectors aiming at increasing LC-PUFA content in vivo. We isolated the cDNAs encoding four fatty acid desaturases (FAD) and determined their function by heterologous expression in S. cerevisiae. To increase the expression of multiple fatty acid desaturases in N. oceanica CCMP1779, we developed a genetic engineering toolkit that includes an endogenous bidirectional promoter and optimized peptide bond skipping 2A peptides. The toolkit also includes multiple epitopes for tagged fusion protein production and two antibiotic resistance genes. We applied this toolkit, towards building a gene stacking system for N. oceanica that consists of two vector series, pNOC-OX and pNOC-stacked. These tools for genetic engineering were employed to test the effects of the overproduction of one, two or three desaturase-encoding cDNAs in N. oceanica CCMP1779 and prove the feasibility of gene stacking in this genetically tractable oleaginous microalga. All FAD overexpressing lines had considerable increases in the proportion of LC-PUFAs, with the overexpression of Δ12 and Δ5 FAD encoding sequences leading to an increase in the final ω3 product, EPA. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Biomonitoring of coastal pollution in the Gulf of Gabes (SE, Tunisia): use of Posidonia oceanica seagrass as a bioindicator and its mat as an archive of coastal metallic contamination.

    Science.gov (United States)

    El Zrelli, Radhouan; Courjault-Radé, Pierre; Rabaoui, Lotfi; Daghbouj, Nabil; Mansour, Lamjed; Balti, Rafik; Castet, Sylvie; Attia, Faouzi; Michel, Sylvain; Bejaoui, Nejla

    2017-10-01

    Within the framework of a study on the extent and history of marine pollution in the central area of Gabes Gulf, the concentrations of four trace metals (Cd, Cu, Pb, and Zn) were assessed in three different tissues of the seagrass species, Posidonia oceanica (leaves, rhizomes, and roots), in the mat of P. oceanica meadows at different depths from the sea floor (- 30 to - 150 cm) and in sediments. The results showed that P. oceanica leaves accumulate more Cd, Cu, and Zn, whereas Pb was found to be more concentrated in roots. The analysis of P. oceanica mat highlighted a clear decreasing gradient of trace metal concentrations from lower (- 30 cm) to higher (- 150 cm) depths. Considering that P. oceanica mat continuously rises above the initial level, with a rate of 1 m per century (~1 cm year -1 ; Molinier and Picard Ann Inst Océanogr Fr 27:157-234, 1952), the latter observation suggested that the pollution level in Gabes Gulf increased continuously during the last few decades. The results of the P. oceanica mapping in the study area showed a continuous regression of its meadows as well as its local disappearance from various areas in the central part of Gabes Gulf. The current status of P. oceanica is most likely due to the cumulative effects of the discharges from the coastal industrial complex of Gabes-Ghannouche represented mainly by the phosphogypsum discharges. This study confirms the usefulness of P. oceanica not only as a bioindicator of the "health status" of coastal ecosystems but also as a record register tracing back the history and temporal evolution of coastal contamination level.

  9. Highly diverse molluscan assemblages of Posidonia oceanica meadows in northwestern Alboran Sea (W Mediterranean): Seasonal dynamics and environmental drivers

    Science.gov (United States)

    Urra, Javier; Mateo Ramírez, Ángel; Marina, Pablo; Salas, Carmen; Gofas, Serge; Rueda, José L.

    2013-01-01

    The seasonal dynamics of the molluscan fauna associated with the westernmost populations of the Mediterranean seagrass Posidonia oceanica, has been studied throughout an annual cycle in the northwestern coasts of the Alboran Sea. Samples were collected seasonally (5 replicated per season) using a non-destructive sampling technique (airlift sampler) on quadrats of 50 × 50 cm at 2 sites located 7 km apart. Several environmental variables from the water column (temperature, chlorophyll a), the sediment (percentage of organic matter) and the seagrass meadows (shoot density, leaf height and width, number of leaves per shoot) were also measured in order to elucidate their relationships with the dynamics of the molluscan assemblages. In these meadows, a total of 17,416 individuals of molluscs were collected, belonging to 71 families and 171 species, being Rissoidae, Pyramidellidae and Trochidae the best-represented families, and Mytilidae, Nassaridae and Trochidae the dominant ones in terms of abundance. The assemblages were dominated by micro-algal grazers, filter feeders and ectoparasites (including those feeding on sessile preys). The species richness and the abundance displayed significant maximum values in summer, whereas evenness and diversity displayed maximum values in spring, being significant for the evenness. Both abundance and species richness values were positively correlated to seawater temperature and percentage organic matter, only for the latter, and negatively to leaf width. Significant seasonal groupings were obtained with multivariate analyses (MDS, Cluster, ANOSIM) using qualitative and quantitative data that could be mainly related to biological aspects (i.e. recruitment) of single species. The molluscan assemblages are influenced by the biogeographical location of the area (Alboran Sea), reflected in the absence or scarcity of most Mediterranean species strictly associated with P. oceanica (e.g. Tricolia speciosa, Rissoa ventricosa) and by the

  10. Perdas de solo e caracterização física e micromorfológica de crostas formadas em solos sob chuva simulada Soil losses and physical and micromorphological characterization of formed crusts in soils under simulated rainfall

    Directory of Open Access Journals (Sweden)

    Viviane dos S. Brandão

    2007-04-01

    Full Text Available Devido aos prejuízos provocados pela erosão sobre sistemas agrários e urbanos, foi desenvolvido este artigo para que se possa estabelecer relação entre a erosão e o selamento formado pelo impacto das gotas de chuva. Para avaliar as perdas de solo e as características físicas e micromorfólogicas das crostas desenvolvidas pelo impacto das gotas de água, foi realizado experimento, utilizando simulador de chuvas, num esquema fatorial 5 x 6, sendo cinco solos (Argissolo Vermelho, Argissolo Vermelho-Amarelo, Latossolo Vermelho-Amarelo, Neossolo Flúvico e Neossolo Quartzarênico e seis energias cinéticas de chuva simulada (0; 525; 1.051; 2.102; 3.153 e 4.204 J m-2, com três repetições. As perdas de solo foram determinadas por amostragem do volume total de escoamento superficial e as características físicas e micromorfológicas da crosta, tais como distribuição e continuidade dos poros, por meio de técnicas de micromorfometria. Em todos os solos avaliados, as perdas de solo aumentaram progressivamente com a energia cinética aplicada, sendo essas perdas menos acentuadas nos solos com textura grossa ou argilosos com estrutura microgranular. Foi evidenciada a formação de crostas estruturais e erosionais, e suas características apresentaram variação temporal dependente da energia cinética da chuva e da tensão cisalhante do escoamento superficial.Due to the damage caused by erosions in land and urban systems, this article has been developed to establish the relation between soil losses and superficial sealing formed by rain drop impact. In order to evaluate soil losses and physical and micromorphological characteristics of soil crusts developed by water drop impact, an experiment was carried out using a rainfall simulator in a factorial scheme of 5 x 6. Five soils (Red Ultisol, Red-Yellow Ultisol, Red-Yellow Oxisol, Fluvic Entisol and Arenic Entisol and six rainfall kinetic energy (0; 525; 1,051; 2,102; 3,153 and 4,204 J m-2 with

  11. Altered epiphyte community and sea urchin diet in Posidonia oceanica meadows in the vicinity of volcanic CO2vents.

    Science.gov (United States)

    Nogueira, Patricia; Gambi, Maria Cristina; Vizzini, Salvatrice; Califano, Gianmaria; Tavares, Ana Mafalda; Santos, Rui; Martínez-Crego, Begoña

    2017-06-01

    Ocean acidification (OA) predicted for 2100 is expected to shift seagrass epiphyte communities towards the dominance of more tolerant non-calcifying taxa. However, little is known about the indirect effects of such changes on food provision to key seagrass consumers. We found that epiphyte communities of the seagrass Posidonia oceanica in two naturally acidified sites (i.e. north and south sides of a volcanic CO 2 vent) and in a control site away from the vent at the Ischia Island (NW Mediterranean Sea) significantly differed in composition and abundance. Such differences involved a higher abundance of non-calcareous crustose brown algae and a decline of calcifying polychaetes in both acidified sites. A lower epiphytic abundance of crustose coralline algae occurred only in the south side of the vents, thus suggesting that OA may alter epiphyte assemblages in different ways due to interaction with local factors such as differential fish herbivory or hydrodynamics. The OA effects on food items (seagrass, epiphytes, and algae) indirectly propagated into food provision to the sea urchin Paracentrotus lividus, as reflected by a reduced P. oceanica exploitation (i.e. less seagrass and calcareous epiphytes in the diet) in favour of non-calcareous green algae in both vent sites. In contrast, we detected no difference close and outside the vents neither in the composition of sea urchin diet nor in the total abundance of calcareous versus non-calcareous taxa. More research, under realistic scenarios of predicted pH reduction (i.e. ≤ 0.32 units of pH by 2100), is still necessary to better understand cascading effects of this altered urchin exploitation of food resources under acidified conditions on ecosystem diversity and function. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Efficient light-harvesting using non-carbonyl carotenoids: Energy transfer dynamics in the VCP complex from Nannochloropsis oceanica.

    Science.gov (United States)

    Keşan, Gürkan; Litvín, Radek; Bína, David; Durchan, Milan; Šlouf, Václav; Polívka, Tomáš

    2016-04-01

    Violaxanthin-chlorophyll a protein (VCP) from Nannochloropsis oceanica is a Chl a-only member of the LHC family of light-harvesting proteins. VCP binds carotenoids violaxanthin (Vio), vaucheriaxanthin (Vau), and vaucheriaxanthin-ester (Vau-ester). Here we report on energy transfer pathways in the VCP complex. The overall carotenoid-to-Chla energy transfer has efficiency over 90%. Based on their energy transfer properties, the carotenoids in VCP can be divided into two groups; blue carotenoids with the lowest energy absorption band around 480nm and red carotenoids with absorption extended up to 530nm. Both carotenoid groups transfer energy efficiently from their S2 states, reaching efficiencies of ~70% (blue) and ~60% (red). The S1 pathway, however, is efficient only for the red carotenoid pool for which two S1 routes characterized by 0.33 and 2.4ps time constants were identified. For the blue carotenoids the S1-mediated pathway is represented only by a minor route likely involving a hot S1 state. The relaxed S1 state of blue carotenoids decays to the ground state within 21ps. Presence of a fraction of non-transferring red carotenoids with the S1 lifetime of 13ps indicates some specific carotenoid-protein interaction that must shorten the intrinsic S1 lifetime of Vio and/or Vau whose S1 lifetimes in methanol are 26 and 29ps, respectively. The VCP complex from N. oceanica is the first example of a light-harvesting complex binding only non-carbonyl carotenoids with carotenoid-to-chlorophyll energy transfer efficiency over 90%. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Depth-acclimation of photosynthesis, morphology and demography of Posidonia oceanica and Cymodocea nodosa in the Spanish Mediterranean Sea

    DEFF Research Database (Denmark)

    Olesen, B.; Enríquez, Susana; Duarte, Carlos M.

    2002-01-01

    and roots at greater depths, thereby promoting the balance between photosynthesis and respiration in the shoots. C. nodosa, being a potentially fast-growing species compared to P. oceanica, had higher maximum photosynthetic and respiration rates as well as light compensation points for photosynthesis....... Photosynthetic efficiency at low light, however, was almost the same for the 2 species as suggested by the relatively small differences in mass-specific light absorption. Only C. nodosa acclimated physiologically to depth as light-use efficiency increased, and light compensation point declined significantly from...... shallow to deep water. P. oceanica, however, possessed low respiration rates and slightly lower light compensation points values than C. nodosa throughout the depth range. Shoot mortality and recruitment rates were unaffected by rooting depth. C. nodosa stand experienced fast shoot turnover compared to P...

  14. Antagonistic roles of abscisic acid and cytokinin during response to nitrogen depletion in oleaginous microalga Nannochloropsis oceanica expand the evolutionary breadth of phytohormone function

    Czech Academy of Sciences Publication Activity Database

    Lu, Y.; Tarkowská, Danuše; Turečková, Veronika; Luo, T.; Xin, Y.; Li, J.; Wang, Q.; Jiao, N.; Strnad, Miroslav; Xu, J.

    2014-01-01

    Roč. 80, č. 1 (2014), s. 52-68 ISSN 0960-7412 R&D Projects: GA ČR GA206/09/1284; GA MŠk LK21306; GA MŠk(CZ) LO1204 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional support: RVO:61389030 Keywords : Nannochloropsis oceanica * antagonistic synergy * abscisic acid Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.972, year: 2014

  15. Mapping of Posidonia oceanica (L. Delile Meadows Using Geographic Information Systems: A case study in Ufakdere - Kaş (Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Volkan Demir

    2016-12-01

    Full Text Available Posidonia oceanica (Linnaeus Delile 1813 is an endemic and the most widespread seagrass species of the Mediterranean Sea. Seagrass meadows are one of the most productive ecosystems on Earth, providing habitat to numerous organisms. Therefore, mapping of seagrass meadows is of crucial importance for conservation and coastal management purposes. Here we present an integrated geographic information system approach with SCUBA diving, providing a cost effective method to monitor seagrass beds at shallow coastal habitats. In this case study P. oceanica meadows were mapped in Ufakdere region of Kaş (Antalya coastal area between April – September 2015. A total of 25000 m2 are were screened to create seagrass coverage maps. Results indicate that P. oceanica meadows cover 21200 m2 and we estimated that 520 m2 of this area is highly damaged. This integrated approach provided one of the most detailed small-scale Posidonia mapping in Turkey and this time and cost effective methodology can be applied to any seagrass meadow with great ease to increase our knowledge on this important habitat.

  16. Lipid metabolism and pro-oxidant/antioxidant balance of Halamphora oceanica from the Gulf of Mexico exposed to water accommodated fraction of Maya crude oil.

    Science.gov (United States)

    Olivares-Rubio, Hugo F; Salazar-Coria, Lucía; Nájera-Martínez, Minerva; Godínez-Ortega, José Luis; Vega-López, Armando

    2018-01-01

    Diatoms play key roles in primary production and carbon fixation at a global scale and in some cases these species live on marine ecosystems impacted by crude oil (CO) spills. Halamphora oceanica, a new diatom species from the Southwest of the Gulf of Mexico was isolated and cultured in the laboratory and was exposed to water accommodated fraction (WAF) of different Maya CO loads at 0.01, 0.1, 1 and 10g/L by 96h. A battery of biomarkers involved in oxidative stress (O 2 •, H 2 O 2 , TBARS, ROOH, RC=O, SOD, CAT, GPx), biotransformation and conjugation (total CYP450 activity and GST) moreover fatty acid (FA) metabolism (FA levels, fatty-acid synthase and acyl-CoA oxidase) were measured. Obtained results suggest that increases of PAHs in the medium (below to EC 50 ) acts as external forces able to turn-on regulatory mechanisms on H. oceanica involved in both, on the PAHs uptake and changing its aerobic metabolism to anaerobic metabolism. However, the growth of this microalgae species evaluated as chlorophyll "a" and pheophytin levels increased as the WAF concentration indicating that PAHs and other hydrosoluble hydrocarbons were used as carbon and energy sources by unidentified enzymes not evaluated in the current study. Our hypothesis was also corroborated by IBRv2. In the current study, we suppose the change from aerobic to anaerobic metabolism as a strategy for Halamphora oceanica survival exposed to petroleum hydrocarbons. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Enhancing the production of eicosapentaenoic acid (EPA) from Nannochloropsis oceanica CY2 using innovative photobioreactors with optimal light source arrangements.

    Science.gov (United States)

    Chen, Chun-Yen; Chen, Yu-Chun; Huang, Hsiao-Chen; Ho, Shih-Hsin; Chang, Jo-Shu

    2015-09-01

    Binary combinations of LEDs with four different colors were used as light sources to identify the effects of multiple wavelengths on the production of eicosapentaenoic acid (EPA) by an isolated microalga Nannochloropsis oceanica CY2. Combining LED-Blue and LED-Red could give the highest EPA productivity of 13.24 mg L(-1) d(-1), which was further enhanced to 14.4 mg L(-1) d(-1) when using semi-batch operations at a 40% medium replacement ratio. A novel photobioreactor with additional immersed light sources improved light penetration efficiency and led to an 38% (0.170-0.235 g L(-1) d(-1)) increase in the microalgae biomass productivity and a 9% decrease in electricity consumption yield of EPA (10.15-9.33 kW-h (g EPA)(-1)) when compared with the control (i.e., without immersed light sources). Operating the immersed LEDs at a flashing-frequency of 9 Hz further lowered the energy consumption yield to 8.87 kW-h (g EPA)(-1). Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Modular antenna of photosystem I in secondary plastids of red algal origin: a Nannochloropsis oceanica case study.

    Science.gov (United States)

    Bína, David; Gardian, Zdenko; Herbstová, Miroslava; Litvín, Radek

    2017-03-01

    Photosystem I (PSI) is a multi-subunit integral pigment-protein complex that performs light-driven electron transfer from plastocyanin to ferredoxin in the thylakoid membrane of oxygenic photoautotrophs. In order to achieve the optimal photosynthetic performance under ambient irradiance, the absorption cross section of PSI is extended by means of peripheral antenna complexes. In eukaryotes, this role is played mostly by the pigment-protein complexes of the LHC family. The structure of the PSI-antenna supercomplexes has been relatively well understood in organisms harboring the primary plastid: red algae, green algae and plants. The secondary endosymbiotic algae, despite their major ecological importance, have so far received less attention. Here we report a detailed structural analysis of the antenna-PSI association in the stramenopile alga Nannochloropsis oceanica (Eustigmatophyceae). Several types of PSI-antenna assemblies are identified allowing for identification of antenna docking sites on the PSI core. Instances of departure of the stramenopile system from the red algal model of PSI-Lhcr structure are recorded, and evolutionary implications of these observations are discussed.

  19. New Bio-Composites Based on Polyhydroxyalkanoates and Posidonia oceanica Fibres for Applications in a Marine Environment

    Science.gov (United States)

    Seggiani, Maurizia; Cinelli, Patrizia; Mallegni, Norma; Balestri, Elena; Puccini, Monica; Vitolo, Sandra; Lardicci, Claudio; Lazzeri, Andrea

    2017-01-01

    Bio-composites based on polyhydroxyalkanoates (PHAs) and fibres of Posidonia oceanica (PO) were investigated to assess their processability by extrusion, mechanical properties, and potential biodegradability in a natural marine environment. PHAs were successfully compounded with PO fibres up to 20 wt % while, at 30 wt % of fibres, the addition of 10 wt % of polyethylene glycol (PEG 400) was necessary to improve their processability. Thermal, rheological, mechanical, and morphological characterizations of the developed composites were conducted and the degradation of composite films in a natural marine habitat was evaluated in a mesocosm by weight loss measure during an incubation period of six months. The addition of PO fibres led to an increase in stiffness of the composites with tensile modulus values about 80% higher for composites with 30 wt % fibre (2.3 GPa) compared to unfilled material (1.24 GPa). Furthermore, the impact energy markedly increased with the addition of the PO fibres, from 1.63 (unfilled material) to 3.8 kJ/m2 for the composites with 30 wt % PO. The rate of degradation was markedly influenced by seawater temperature and significantly promoted by the presence of PO fibres leading to the total degradation of the film with 30 wt % PO in less than six months. The obtained results showed that the developed composites can be suitable to manufacture items usable in marine environments, for example, in natural engineering interventions, and represent an interesting valorisation of the PO fibrous wastes accumulated in large amounts on coastal beaches. PMID:28772689

  20. Deep divergence and structure in the Tropical Oceanic Pacific: a multilocus phylogeography of a widespread gekkonid lizard (Squamata: Gekkonidae: Gehyra oceanica)

    Science.gov (United States)

    Tonione, Maria A.; Fisher, Robert N.; Zhu, Catherine; Moritz, Craig

    2016-01-01

    Aim The islands of the Tropical Oceanic Pacific (TOP) host both local radiations and widespread, colonizing species. The few phylogeographical analyses of widespread species often point to recent human-aided expansions through the Pacific, suggesting that the communities are recently assembled. Here we apply multilocus data to infer biogeographical history of the gekkonid lizard, Gehyra oceanica, which is widespread, but for which prior analyses suggested a pre-human history and in situ diversification. Location Tropical Oceanic Pacific. Methods We generated a data set including mtDNA and diagnostic SNPs for 173 individuals of G. oceanica spanning Micronesia, Melanesia, and Polynesia. For a subset of these individuals, we also sequenced nuclear loci. From these data, we performed maximum likelihood and Bayesian inference to reveal major clades. We also performed Bayesian clustering analyses and coalescence–based species delimitation tests to infer the number of species in this area. Results We found evidence for six independent evolutionary lineages (candidate species) within G. oceanica that diverged between the Pliocene and the early Pleistocene, with high diversity through northern Melanesia, and pairing of northern Melanesian endemic taxa with widespread lineages across Micronesia and Polynesia. Main conclusions The islands of northern Melanesia not only have unrecognized diversity, but also were the source of independent expansions of lineages through the more remote northern and eastern Pacific. These results highlight the very different evolutionary histories of island faunas on remote archipelagos versus those across Melanesia and point to the need for more intensive studies of fauna within Melanesia if we are to understand the evolution of diversity across the tropical Pacific.

  1. The complete mitochondrial genome of the common sea slater, Ligia oceanica (Crustacea, Isopoda bears a novel gene order and unusual control region features

    Directory of Open Access Journals (Sweden)

    Podsiadlowski Lars

    2006-09-01

    Full Text Available Abstract Background Sequence data and other characters from mitochondrial genomes (gene translocations, secondary structure of RNA molecules are useful in phylogenetic studies among metazoan animals from population to phylum level. Moreover, the comparison of complete mitochondrial sequences gives valuable information about the evolution of small genomes, e.g. about different mechanisms of gene translocation, gene duplication and gene loss, or concerning nucleotide frequency biases. The Peracarida (gammarids, isopods, etc. comprise about 21,000 species of crustaceans, living in many environments from deep sea floor to arid terrestrial habitats. Ligia oceanica is a terrestrial isopod living at rocky seashores of the european North Sea and Atlantic coastlines. Results The study reveals the first complete mitochondrial DNA sequence from a peracarid crustacean. The mitochondrial genome of Ligia oceanica is a circular double-stranded DNA molecule, with a size of 15,289 bp. It shows several changes in mitochondrial gene order compared to other crustacean species. An overview about mitochondrial gene order of all crustacean taxa yet sequenced is also presented. The largest non-coding part (the putative mitochondrial control region of the mitochondrial genome of Ligia oceanica is unexpectedly not AT-rich compared to the remainder of the genome. It bears two repeat regions (4× 10 bp and 3× 64 bp, and a GC-rich hairpin-like secondary structure. Some of the transfer RNAs show secondary structures which derive from the usual cloverleaf pattern. While some tRNA genes are putative targets for RNA editing, trnR could not be localized at all. Conclusion Gene order is not conserved among Peracarida, not even among isopods. The two isopod species Ligia oceanica and Idotea baltica show a similarly derived gene order, compared to the arthropod ground pattern and to the amphipod Parhyale hawaiiensis, suggesting that most of the translocation events were already

  2. Identification of a malonyl CoA-acyl carrier protein transacylase and its regulatory role in fatty acid biosynthesis in oleaginous microalga Nannochloropsis oceanica.

    Science.gov (United States)

    Chen, Jia-Wen; Liu, Wan-Jun; Hu, Dong-Xiong; Wang, Xiang; Balamurugan, Srinivasan; Alimujiang, Adili; Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye

    2017-09-01

    Oleaginous microalgae hold great promises for biofuel production. However, commercialization of microalgal biofuels remains impracticable due to the lack of suitable industrial strains with high growth rate and lipid productivity. Engineering of metabolic pathways is a potential strategy for the improvement of microalgal strains for the production of lipids and also value-added products in microalgae. Malonyl CoA-acyl carrier protein transacylase (MCAT) has been reported to be involved in fatty acid biosynthesis. Here, we identified a putative MCAT in the oleaginous marine microalga Nannochloropsis oceanica. NoMCAT overexpressing N. oceanica showed a higher growth rate and photosynthetic efficiency. The neutral lipid content of engineered lines showed a significant increase by up to 31% compared to wild type. Gas chromatography-mass spectrometry analysis revealed that NoMCAT overexpression significantly altered the fatty acid composition. The composition of eicosapentaenoic acid (C20:5), which is a polyunsaturated fatty acid necessary for animal nutrition, increased by 8%. These results demonstrate the role of MCAT in enhancing fatty acid biosynthesis and growth in microalgae, and also provide an insight into metabolic engineering of microalgae with high industrial potential. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  3. A methodological approach to understand functional relationships between ecological indices and human-induced pressures: the case of the Posidonia oceanica meadows.

    Science.gov (United States)

    Bacci, Tiziano; Rende, Sante Francesco; Penna, Marina; Trabucco, Benedetta; Montefalcone, Monica; Cicero, Anna Maria; Giovanardi, Franco

    2013-11-15

    The European Water Framework Directive (WFD) 2000/60/EC requests the achievement of the Good Status for all surface waters, including the coastal waters, by 2015. In order to check compliance with the needs of Directive, Italian national monitoring data on Posidonia oceanica meadows have been explored and the relationships among the Posidonia Rapid and Easy Index (PREI), and human-induced pressures have been analyzed along the Italian coasts. The aim of this work is to establish functional relationships between a response variable (i.e. the PREI) and a set of potential pressure (i.e. land use, potential organic and nutrient loading, pesticides) and status (i.e. transparency, trophic level and stability of the water column) indicators in a quantitative way. The ecological responses of coastal marine environment have been evaluated using appropriate statistical tools, such as the multiple linear regression analyses and "linear programming" techniques. Results show that more than 70% of the variability of the P. oceanica meadows status, expressed as PREI value, is significantly explained only by a few pressure/status indicators (namely: potential organic load, specific nitrogen load, natural areas extent, water column transparency), among all those initially considered in the model. The application of the proposed model could allow decision makers to better address remedial actions and to achieve the environmental targets proposed by the EU Directives. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Effect of ammonium and high light intensity on the accumulation of lipids in Nannochloropsis oceanica (CCAP 849/10) and Phaeodactylum tricornutum (CCAP 1055/1).

    Science.gov (United States)

    Huete-Ortega, María; Okurowska, Katarzyna; Kapoore, Rahul Vijay; Johnson, Matthew P; Gilmour, D James; Vaidyanathan, Seetharaman

    2018-01-01

    Microalgae accumulate lipids when exposed to stressful conditions such as nutrient limitation that can be used to generate biofuels. Nitrogen limitation or deprivation is a strategy widely employed to elicit this response. However, this strategy is associated with a reduction in the microalgal growth, leading to overall poor lipid productivities. Here, we investigated the combined effect of a reduced source of nitrogen (ammonium) and super-saturating light intensities on the growth and induction of lipid accumulation in two model but diverse microalgal species, Phaeodactylum tricornutum and Nannochloropsis oceanica . We hypothesized that the lower energy cost of assimilating ammonium would allow the organisms to use more reductant power for lipid biosynthesis without compromising growth and that this would be further stimulated by the effect of high light (1000 µmol m -2 s -1 ) stress. We studied the changes in growth and physiology of both species when grown in culture media that either contained nitrate or ammonium as the nitrogen source, and an additional medium that contained ammonium with tungsten in place of molybdenum and compared this with growth in media without nitrogen. We focused our investigation on the early stages of exposure to the treatments to correspond to events relevant to induction of lipid accumulation in these two species. At super-saturating light intensities, lipid productivity in P. tricornutum increased twofold when grown in ammonium compared to nitrogen free medium that increased further when tungsten was present in the medium in place of molybdenum. Conversely, N. oceanica growth and physiology was not compromised by the high light intensities used, and the use of ammonium had a negative effect on the lipid productivity, which was even more marked when tungsten was present. Whilst the use of ammonium and super-saturating light intensities in P. tricornutum was revealed to be a good strategy for increasing lipid biosynthesis, no

  5. Ocean Color Products Supporting the Assessment of Good Environmental Status: Development of a Spatial Distribution Model for the Seagrass Posidonia Oceanica (L.) Delille, 1813

    Science.gov (United States)

    Zucchetta, M.; Taji, M. A.; Mangin, A.; Pastres, R.

    2015-12-01

    Posidonia oceanica (L.) Delile, 1813 is a seagrass species endemic to the Mediterranean Sea, which is considered as one of the key habitats of the coastal areas. This species forms large meadows sensitive to several anthropogenic pressures, that can be regarded as indicators of environment quality in coastal environments and its distributional patterns should be take into account when evaluating the Environmental Status following the Ecosystem approach promoted by the Mediterranean Action Plan of UNEP and the EU Marine Strategy Framework Directive (2008/56/EC). The aim of this study was to develop a Species Distribution Model for P. oceanica, to be applied to the whole Mediterranean North African coast, in order to obtain an estimation of the potential distribution of this species in the region to be considered as an indicator for the assessment of good Environmental Status. As the study area is a data-poor zone with regard to seagrass distribution (i.e. only for some areas detailed distribution maps are available), the Species Distribution Model (SDM) was calibrated using high resolution data from 5 Mediterranean sites, located in Italy and Spain and validated using available data from the North African coast. Usually, when developing SDMs species occupancy data is available at coarser resolution than the information of environmental variables, and thus has to be downscaled at the appropriate grain to be coupled to the environmental conditions. Tackling the case of P. oceanica we had to face the opposite problem: the quality (in terms of resolution) of the information on seagrass distribution is generally very high compared to the environmental data available over large scale in marine domains (e.g. global bathymetry data). The high resolution application and the model transfer (from calibration areas to North African coast) was possible taking advantage of Ocean Color products: the probability of presence of the species in a given area was modelled using a

  6. Variability in the structure of epiphytic microalgae assemblages on the leaves of Posidonia oceanica in relation to human disturbance in a meadow off Tunisia

    Directory of Open Access Journals (Sweden)

    Lotfi Mabrouk

    2014-03-01

    Full Text Available We investigated the impact of sewage discharge on Posidonia oceanica meadows in Mahdia, eastern Tunisia. We specifically addressed changes in biometric plant parameters and epiphytic microalgae composition on leaves caused by this anthropogenic interference. A hierarchical sampling design was used to compare epiphytic microalgae structure between one disturbed and two control stations. Samples were collected by SCUBA diving at 8 m depth in August 2009. A total of 58 microalgae taxa were identified on leaves. At the disturbed station, leaf length, leaf surface area and the leaf area index decreased, whereas epiphytic dinoflagellate abundances increased compared with the control stations, with more Prorocentrales, Protoperidiniales and potentially toxic species on leaves of the disturbed station. Moderate nutrient enrichment (mainly Si(OH4 and NH4+ and low water transparency at the disturbed station were associated with the increased abundances of some dinoflagellate species.

  7. Antagonistic roles of abscisic acid and cytokinin during response to nitrogen depletion in oleaginous microalga Nannochloropsis oceanica expand the evolutionary breadth of phytohormone function.

    Science.gov (United States)

    Lu, Yandu; Tarkowská, Danuše; Turečková, Veronika; Luo, Tingwei; Xin, Yi; Li, Jing; Wang, Qintao; Jiao, Nianzhi; Strnad, Miroslav; Xu, Jian

    2014-10-01

    The origin of phytohormones is poorly understood, and their physiological roles in microalgae remain elusive. Genome comparison of photosynthetic autotrophic eukaryotes has revealed that the biosynthetic pathways of abscisic acid (ABA) and cytokinins (CKs) emerged in unicellular algae. While ABA and CK degradation mechanisms emerged broadly in algal lineages, complete vascular plant-type conjugation pathways emerged prior to the rise of Streptophyta. In microalgae, a complete set of proteins from the canonical ABA and CK sensing and signaling pathways is not essential, but individual components are present, suggesting stepwise recruitment of phytohormone signaling components. In the oleaginous eustigmatophyte Nannochloropsis oceanica IMET1, UHPLC-MS/MS detected a wide array of plant hormones, despite a phytohormone profile that is very distinct from that of flowering plants. Time-series transcriptional analysis during nitrogen depletion revealed activation of the ABA biosynthetic pathway and antagonistic transcription of CK biosynthetic genes. Correspondingly, the ABA level increases while the dominant bioactive CK forms decrease. Moreover, exogenous CKs stimulate cell-cycle progression while exogenous ABA acts as both an algal growth repressor and a positive regulator in response to stresses. The presence of such functional flowering plant-like phytohormone signaling systems in Nannochloropsis sp. suggests a much earlier origin of phytohormone biosynthesis and degradation than previously believed, and supports the presence in microalgae of as yet unknown conjugation and sensing/signaling systems that may be exploited for microalgal feedstock development. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  8. Bioaccumulation of aluminium in the seagrasses Cymodocea nodosa (Ucria) Aschers. and Posidonia oceanica (L.) Delile and macroalgae of the Gulf of Antikyra (Greece)

    Energy Technology Data Exchange (ETDEWEB)

    Malea, P. [Thessaloniki Univ. (Greece). Inst. of Botany

    1993-12-31

    Mean concentrations of Aluminium ({+-}SE) in two seagrasses, four Chlorophytes, three Chromophytes and seven Rhodophyte species from the Gulf of Antikyra (Greece) decreased in the order: Chlorophyta > Chromophyta > Rhodophyta > P. oceanica > C. nodosa. This area is of particular interest because of the bauxite composition of the substrate and of the wate discharge from an aluminium factory in the Gulf. Aluminium concentrations in the two seagrasses were evenly distributed at the Gulf stations. Only the concentrations of Al in C. nodosa displayed significant seasonal variation. The mean concentrations increased from spring to summer, at which point they reached their maxima. This pattern is discussed in relation to the leaf-age of the seagrass. Regarding the amount of Al accumulated by the macroalgae of each division, there were interspecific differences which were attributed to differences in the structure, the ecology and the binding sites offered by the plants. The dependence of Al concentrations in the macrophytes on the concentrations in the sediment and the correlation of Al concentrations with the concentrations of some other metals in the plants were also investigated. (orig.)

  9. Determination of trace metal baseline values in Posidonia oceanica, Cystoseira sp., and other marine environmental biomonitors: a quality control method for a study in South Tyrrhenian coastal areas.

    Science.gov (United States)

    Conti, Marcelo Enrique; Mecozzi, Mauro; Finoia, Maria Grazia

    2015-03-01

    In this study, we investigated Cd, Cr, Cu, Pb, and Zn in the seagrass Posidonia oceanica (L.) Delile leaves and in the brown algae Cystoseira sp. sampled along a 280-km transect in the Tyrrhenian Sea, from the Ustica to Linosa Islands (Sicily, Italy) with the aim to determine their control charts (baseline levels). By applying the Johnson's (Biometrika 36:149-175, 1949) probabilistic method, we determined the metal concentration overlap ranges in a group of five biomonitors. Here, we propose the use of the indexes of bioaccumulation with respect to the lowest (L'i) and the highest (L i) extreme values of the overlap metal concentration ranges. These indexes allow the identification of the most opportune organism (or a suite of them) to better managing particular environmental conditions. Posidonia leaves have generally high L i indexes for Cd, Cu, Pb, and Zn, and this suggests its use as biomonitor for baseline marine areas. Our results confirm the high aptitude of Patella as a good biomonitor for Cd levels in seawater. From this study, Ustica resulted with higher levels of Cd, Cu, Pb, and Zn than the other Sicilian Islands.

  10. Enhancement of biofuels production by means of co-pyrolysis of Posidonia oceanica (L.) and frying oil wastes: Experimental study and process modeling.

    Science.gov (United States)

    Zaafouri, Kaouther; Ben Hassen Trabelsi, Aida; Krichah, Samah; Ouerghi, Aymen; Aydi, Abdelkarim; Claumann, Carlos Alberto; André Wüst, Zibetti; Naoui, Silm; Bergaoui, Latifa; Hamdi, Moktar

    2016-05-01

    Energy recovery from lignocellulosic solid marine wastes, Posidonia oceanica wastes (POW) with slow pyrolysis responds to the growing trend of alternative energies as well as waste management. Physicochemical, thermogravimetric (TG/DTG) and spectroscopic (FTIR) characterizations of POW were performed. POW were first converted by pyrolysis at different temperatures (450°C, 500°C, 550°C and 600°C) using a fixed-bed reactor. The obtained products (bio-oil, syngas and bio char) were analyzed. Since the bio-oil yield obtained from POW pyrolysis is low (2wt.%), waste frying oil (WFO) was added as a co-substrate in order to improve of biofuels production. The co-pyrolysis gave a better yield of liquid organic fraction (37wt.%) as well as syngas (CH4,H2…) with a calorific value around 20MJ/kg. The stoichiometric models of both pyrolysis and co-pyrolysis reactions were performed according to the biomass formula: CαHβOγNδSε. The thermal kinetic decomposition of solids was validated through linearized Arrhenius model. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Microbiological parameters and maturity degree during composting of Posidonia oceanica residues mixed with vegetable wastes in semi-arid pedo-climatic condition.

    Science.gov (United States)

    Saidi, Neyla; Kouki, Soulwene; M'hiri, Fadhel; Jedidi, Naceur; Mahrouk, Meriam; Hassen, Abdennaceur; Ouzari, Hadda

    2009-01-01

    The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with residues of Posidonia oceanica (PoR), collected from Tunis beaches. The accumulation in beaches (as well as their removal) constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion: (a) C/N ratio 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N (13.0 g/kg), P (4.74 g/kg) and MgO (15.80 g/kg). Thus composting definitively constitutes the most optimal option to exploit these wastes.

  12. Human impact, geomorphological and bio-environmental indicators for mapping and monitoring of a Mediterranean urban-beach with Posidonia oceanica (Gulf of Cagliari-Sardinia)

    Science.gov (United States)

    De Muro, Sandro; Pusceddu, Nicola; Frongia, Paolo; Buosi, Carla; Passarella, Marinella; Ibba, Angelo

    2016-04-01

    This work describes the human conditioned evolution (medium term) and the short term dynamics (mainly sediment transport) in southern Sardinia beach (between Giorgino and Cala d'Orri, about 11km), composed of fine to coarse quartz sand, backed by dune ridges and lagoons. The study was founded by NEPTUNE Project, Tender6 (L n. 7/2007). Geomorphological and bio-environmental indicators as: urbanization and coastal defence expansion, dune and beach changes, biotic indices (benthic foraminifera and Posidonia meadow) have been used. Medium-term evolution, over a period of 60 years, was carried out by ortho-images (1954-2015) for reconstructing coastline changes at this temporal scale. The main modifications were the building of the canal harbor, the consequent loss of 2.5km of beach, and the construction of several coastal defense structures, which caused asymmetric accumulations (lee zones) and erosion areas. Short-term variations have been periodically monitored (2014-2015) during 5 different field surveys (DGPS and Echo-sounder data) obtaining topo-bathymetric digital models. Sedimentary and hydrodynamic characteristics have been studied. Wave propagation, coastal currents and sediment transport, have been simulated through numerical models within Delft3D software. The results obtained allowed to visualize the response of the beach to wave stress, forced from SW, S, SE (Cagliari buoy and weather data). The comparison between data collected, thematic maps and models allowed to identify the main controlling factors and distribution mechanisms of the sedimentary paths on the shoreface. Those human modifications (e.g. building of the canal harbour and jetties, lagoon mouths stabilization, the consequent modified hydrodynamics and bottom trawling) have direct influence on the Posidonia oceanica and on its upper limit. In 2002, the Italian Environment Office reported a wide area (between -4m and -20m) of degraded Posidonia and dead matte in front of the study beach

  13. La Biomasa de epífitos de la angiosperma marina Posidonia oceanica (L.) Delile no es indicadora de aportes antropogénicos de nutrientes en el Parque Nacional Archipiélago de Cabrera (Islas Baleareas, Mediterráneo Occidental)

    OpenAIRE

    Terrados, Jorge; Medina Pons, Francisco Javier

    2008-01-01

    [ES] La biomasa de epífitos y el contenido en cenizas de los mismos, la biomasa foliar del haz, el contenido en nitrógeno de las hojas y la densidad de haces de la angiosperma marina Posidonia oceanica (L.) Delile se midieron en tres localidades y a dos profundidades (7 m, 17 m) del Parque Nacional Archipiélago de Cabrera (Islas Baleares, Mediterráneo Occidental) en los meses de septiembre del período 2004-2006 para evaluar el valor de la biomasa de epífitos como indicador de aportes antropog...

  14. Multidisciplinary projects and investigations on the solid earth geophysics; Metodi e prospettive per una maggiore conoscenza della crosta terrestre

    Energy Technology Data Exchange (ETDEWEB)

    Slejko, D. [Consiglio Nazionale delle Ricerche, Gruppo Nazionale di Geofisica della Terra Solida, Trieste (Italy)

    2001-07-01

    Physical phenomena that occur in the solid part of the Earth are investigated by Solid Earth Geophysics together with problems related to the shape, location, and characteristics of the different parts that constitute the Earth. Repeated measurements lead the scientists to model the past evolution of the various processes as well as to forecast the future ones. Various disciplines refer to Solid Earth Geophysics, they are: Seismology, Gravimetry, Magnetometry, Geothermics, Geodesy, Geo electromagnetism, and Seismic Exploration. A special citation is due to Applied Geophysics, which are devoted to the identification of minerals, energetic and natural resources. The National Group of Solid Earth Geophysics was constituted in 1978 by CNR for promoting, developing, and coordinating researches related to Solid Earth Geophysics. The limited annual financial budget has conditioned the realisation of relevant multi-disciplinary projects. Nevertheless, important results were obtained in all different fields of Geophysics and were disseminated during the annual conference of the Group. A summary review of the main topics treated during the last conference is given here and some ideas for future research projects are presented. [Italian] La Geofisica della Terra Solida e' quella branca delle scienze e delle tecnologie che prende in considerazione dei fenomeni connessi con le caratteristiche fisiche della parte solida della Terra. La complessita' della costituzione della Terra e della sua evoluzione nel tempo implica che vengano prese in considerazione tutte le fenomenologie che si riescono a misurare e che costituiscono branche diverse della Geofisica: la Sismologia, la Gravimetria, la Magnetometria, la Geotermia, la Geodesia, il Geoelettromagnetismo, la Geofisica applicata. Ognuna di queste branche della Geofisica ha avuto in passato uno sviluppo quasi del tutto indipendente con collaborazioni o integrazioni dirtte ad obiettivi specifici, limitati anche nel tempo. Il Gruppo Nazionale di Geofisica della Terra Solida (GNGTS) e' stato istituito dal CNR, per iniziativa dei Comitati per le Scienze Fisiche e per le Scienze Geologiche ed ha avuto come principale scopo quello di avvicinare e far interagire i ricercatori non solo delle varie branche della Geofisica ma anche delle varie scuole che si erano sviluppate in Italia, di far conoscere e confrontare le metodologie e le tecniche sviluppate, di promuovere ricerche, seminari, convegni, in cui le varie realta' si potessero confrontare ed integrare, anche per una nuova o rinnovata conoscenza personale.

  15. Dr. Zompo : An online data repository for Zostera marina and Posidonia oceanica ESTs

    NARCIS (Netherlands)

    Wissler, L.; Dattolo, E.; Moore, A. D.; Reusch, T. B. H.; Olsen, J. L.; Migliaccio, M.; Bornberg-Bauer, E.; Procaccini, G.

    2009-01-01

    As ecosystem engineers, seagrasses are angiosperms of paramount ecological importance in shallow shoreline habitats around the globe. Furthermore, the ancestors of independent seagrass lineages have secondarily returned into the sea in separate, independent evolutionary events. Thus, understanding

  16. Architecture of the light-harvesting apparatus of the eustigmatophyte alga Nannochloropsis oceanica

    Czech Academy of Sciences Publication Activity Database

    Litvín, Radek; Bína, David; Herbstová, Miroslava; Gardian, Zdenko

    2016-01-01

    Roč. 130, 1-3 (2016), s. 137-150 ISSN 0166-8595 R&D Projects: GA ČR(CZ) GP14-01377P Institutional support: RVO:60077344 Keywords : Light harvesting * Thylakoid membrane * Vaucheriaxanthin * Violaxanthin–chlorophyll protein Subject RIV: BO - Biophysics Impact factor: 3.864, year: 2016

  17. Settlement pattern of Posidonia oceanica epibionts along a gradient of ocean acidification: an approach with mimics

    Directory of Open Access Journals (Sweden)

    L. DONNARUMMA

    2014-02-01

    Full Text Available Effects of ocean acidification (OA on the colonization/settlement pattern of the epibiont community of the leaves and rhizomesof the Mediterranean seagrass,Posidoniaoceanica, have been studied at volcanic CO2vents off Ischia (Italy, using “mimics”as artificial substrates. The experiments were conducted in shallowPosidoniastands (2-3 m depth, in three stations on the northand three on the south sides of the study area, distributed along a pH gradient. At each station, 4 rhizome mimics and 6 artificialleaves were collected every three months (Sept 2009-Sept 2010. The epibionts on both leaf and rhizome mimics showed clearchanges along the pH gradient; coralline algae and calcareous invertebrates (bryozoans, serpulid polychaetes and barnacles weredominant at control stations but progressively disappeared at the most acidified stations. In these extremely low pH sites theassemblage was dominated by filamentous algae and non calcareous taxa such as hydroids and tunicates. Settlement pattern onthe artificial leaves and rhizome mimics over time showed a consistent distribution pattern along the pH gradient and highlightedthe peak of recruitment of the various organisms in different periods according to their life history.Posidoniamimics at theacidified station showed a poor and very simplified assemblage where calcifying epibionts seemed less competitive for space. Thisprofound difference in epiphyte communities in low pH conditions suggests cascading effects on the food web of the meadow and,consequently, on the functioning of the system

  18. Anatomically and morphologically unique dark septate endophytic association in the roots of the Mediterranean endemic seagrass Posidonia oceanica

    Czech Academy of Sciences Publication Activity Database

    Vohník, Martin; Borovec, Ondřej; Župan, I.; Vondrášek, D.; Petrtýl, M.; Sudová, Radka

    2015-01-01

    Roč. 25, č. 8 (2015), s. 663-672 ISSN 0940-6360 R&D Projects: GA ČR GAP504/10/0781 Institutional support: RVO:67985939 Keywords : seagrasses * fungal symbioses * Mediterranean Sea Subject RIV: EF - Botanics Impact factor: 3.252, year: 2015

  19. Modular antenna of photosystem I in secondary plastids of red algal origin: a Nannochloropsis oceanica case study

    Czech Academy of Sciences Publication Activity Database

    Bína, David; Gardian, Zdenko; Herbstová, Miroslava; Litvín, Radek

    2017-01-01

    Roč. 131, č. 3 (2017), s. 255-266 ISSN 0166-8595 R&D Projects: GA ČR(CZ) GP14-01377P Institutional support: RVO:60077344 Keywords : light-harvesting complexes * diatom phaeodactylum-tricornutum * em structure determination Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 3.864, year: 2016

  20. Utilisation de Posidonia oceanica (L.) Delile comme bio-indicateur de la contamination métallique

    OpenAIRE

    Lafabrie, Céline

    2007-01-01

    La zone littorale du plateau continental renferme une grande richesse écologique. Or, cette zone présente une grande fragilité vis-à-vis des xénobiotiques ; la pollution de ce milieu peut porter atteinte à la structure des biocénoses et à la productivité des écosystèmes. Les métaux sont des constituants normaux de l'environnement à l'état de traces, contrairement à de nombreux contaminants, et sont tous toxiques au dessus d'un certain seuil. A la fin des années 1970, plusieurs chercheurs prop...

  1. Spanish leadership in marine renewable energies. The project Ocean Lider; Liderazgo espanol en energias renovables oceanicas. El proyecto Ocean Lider

    Energy Technology Data Exchange (ETDEWEB)

    Amante, J.

    2012-07-01

    The Cenit-e Ocean Lider project is an ambitious R+D technological initiative promoted by a consortium of companies with a strong research capability which addresses the challenge of developing the necessary technologies to set up integrated large scale installations that can harness energies of marine renewable sources, such as waves, tidal currents and wind. Ocean Lider developed knowledge and technologies would provide some new power plant concepts, devices, structures, data acquisition and site characterization systems, vessels, etc. In this way, some new technologies for harnessing ocean energy generation, distribution and transmission would be developed and sized according to a large scale scheme, to make this hybrid harvest (wave, current and wind) as profitable as possible. (Author)

  2. Efficient light-harvesting using non-carbonyl carotenoids: Energy transfer dynamics in the VCP complex from Nannochloropsis oceanica

    Czech Academy of Sciences Publication Activity Database

    Kesan, G.; Litvín, Radek; Bína, David; Durchan, Milan; Šlouf, V.; Polívka, Tomáš

    2016-01-01

    Roč. 1857, č. 4 (2016), s. 370-379 ISSN 0005-2728 R&D Projects: GA ČR(CZ) GAP205/11/1164; GA ČR GBP501/12/G055; GA ČR(CZ) GP14-01377P Institutional support: RVO:60077344 Keywords : Carotenoids * Energy transfer * Light-harvesting complex Subject RIV: BO - Biophysics Impact factor: 4.932, year: 2016

  3. Metamorfismo da fácies granulito em 570-580 Ma no Complexo Granulítico Porangatu, centro do Brasil: implicações para a evolução do Lineamento Transbrasiliano

    Directory of Open Access Journals (Sweden)

    Paulo Sergio de Sousa Gorayeb

    ,1 Ga, indicando protólito ígneo do Paleoproterozoico envolvidos no metamorfismo de alto grau no Neoproterozoico. Além disso, os grãos de zircão mais antigos herdados de 3,1 e 2,0 Ga (idades 207Pb/206Pb em charnockito também confirma a existência de material Arqueano e Paleoproterozoico nesta região, possivelmente derivado do Maciço de Goiás. Um grão de zircão herdado de 0,88 Ga é sugestivo de derivação do Arco Magmático de Goiás. Essa idade neoproterozoica para o metamorfismo de alto grau é substancialmente mais jovem do que a relatada para outros granulitos do Cinturão Brasília (cerca de 0,65 Ga, sugerindo que o Complexo Granulítico Porangatu está mais provavelmente associado à evolução do Cinturão Araguaia mais jovem. Os novos dados de campo, estruturais, petrográficos, e geocronológicos, sugerem que o Complexo Granulítico Porangatu foi envolvido em uma expressiva zona de cisalhamento transcorrente dúctil estabelecida em alta temperatura, que justapôs unidades de rochas de diferentes idades (Arqueano, Paleoproterozoico, Neoproterozoico, naturezas e níveis crustais (crosta continental inferior e média fortemente retrabalhadas nos estágios finais da orogenia Brasiliano e representam as raízes expostas do Orógeno Tocantins.

  4. Efecto de una posible interacción entre el pH y la salinidad sobre el crecimiento de Posidonia oceanica (L.) Delile, 1813

    OpenAIRE

    Fernández-Torquemada, Yolanda; Sánchez-Lizaso, José Luis

    2003-01-01

    La desalación de aguas marinas mediante ósmosis inversa es una actividad en desarrollo en la cuenca mediterránea cuyos posibles impactos ambientales son poco conocidos. El agua de rechazo de dichas plantas posee una elevada salinidad y un pH relativamente bajo. En el presente trabajo se realizaron experimentos en mesocosmos para estimar el efecto de una posible interacción entre dicho descenso del pH y el incremento de la salinidad sobre el crecimiento de la fanerógama marina Posidonia oce...

  5. Communities of cultivable root mycobionts of the seagrass Posidonia oceanica in the northwest Mediterranean Sea are dominated by a hitherto undescribed pleosporalean dark septate endophyte

    Czech Academy of Sciences Publication Activity Database

    Vohník, Martin; Borovec, Ondřej; Kolařík, Miroslav

    2016-01-01

    Roč. 71, č. 2 (2016), s. 442-451 ISSN 0095-3628 Institutional support: RVO:67985939 ; RVO:61388971 Keywords : seagrasses * fungal symbioses * Mediterranean Sea Subject RIV: EH - Ecology, Behaviour; EE - Microbiology, Virology (MBU-M) Impact factor: 3.630, year: 2016

  6. Mapping hydrothermal altered mineral deposits using Landsat 7 ...

    Indian Academy of Sciences (India)

    The colour composite and band ratio methods showed very clearly the hydrothermal altered deposits of clay minerals, iron oxides and ferric oxides around the fumaroles. The principal component analysis using the Crosta technique also enabled us to represent undoubtedly the altered hydroxyl and iron-oxide mineral ...

  7. Mapping hydrothermal altered mineral deposits using Landsat 7 ...

    Indian Academy of Sciences (India)

    To evaluate the conventional methods for mapping hydrothermal altered deposits by using Landsat 7. ETM+ image in and around ... component analysis using the Crosta technique also enabled us to represent undoubtedly the altered hydroxyl and ..... target detection algorithms for hyperspectral imagery; In: Algorithms and ...

  8. The multidisciplinary PhD course: A history and a way forward

    Directory of Open Access Journals (Sweden)

    Ruba Saleh

    2015-12-01

    Full Text Available This paper attempts to trace the last three decades of the PhD in Regional Planning and Public Policies (RPPP at Iuav, Venice.  The programme started in 1985; fifteen years after Giovanni Astengo established an undergraduate course in urban planning at the Iuav  Venice University of Architecture. Astengo was a leading authority on urban planning in the twentieth century, and the founder of the first graduate urban planning program in Italy. On the national level he was a vigorously active urban planner, who contributed both to the drafting of several Italian laws concerning the protection of the territory and landscape,(DOES "protection of the territory and landscape" simply mean 'the environment'? and a number of far-reaching plans. Astengo was the honorary president of the Italian National Institute of Planning (INU from 1986 to 1990.  He also re-founded the magazine Urbanistica, the magazine of the INU in 1949 and directed it for almost three decades.Another significant pioneer, Pierluigi Crosta who coordinated the course for two decades, was, and still is, a leader in the theory and development of the discipline.  Professor Crosta had a clear vision which he communicated to his students. In 2010, Crosta retired and many changes came about. A new coordinator was appointed with a new teaching plan. This paper has two objectives. First of all, it will aim to trace the contributions of Crosta to development of the subject at national level. Secondly, it will try to reflect the viewpoints of some of the PhD candidates who experienced the transition after Crosta, as a way to improve the methodology and organizational structure. Finally, it will speculate on the possibility of establishing a research centre at Iuav for the advancement of studies on contemporary cities.

  9. Nannoplankton from the Bombay-Saurashtra continental shelf of India: An appraisal using cluster analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.; Nigam, R.

    Nannoplankton data from 28 stations in the northwestern continental shelf of India was subjected to Q-mode cluster analysis. Two biotopes A and B were identified. Although, Gephyrocapsa oceanica was by far, the most abundant species in both...

  10. Carbon and nitrogen translocation between seagrass ramets

    NARCIS (Netherlands)

    Marbà, N.; Hemminga, M.A.; Mateo, M.A.; Duarte, C.M.; Maas, Y.E.M.; Terrados, J.; Gacia, E.

    2002-01-01

    The spatial scale and the magnitude of carbon and nitrogen translocation was examined in 5 tropical (Cymodocea serrulata, Halophila stipulacea, Halodule uninervis, Thalassodendron ciliatum, Thalassia hemprichii) and 3 temperate (Cymodocea nodosa, Posidonia oceanica, Zostera noltii) seagrass species

  11. Living coccolithophores during the northeast monsoon from the Equatorial Indian Ocean: Implications on hydrography

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha; Mergulhao; Murty, V.S.N.; Shenoy

    of coccoliths were observed at shallow depths (less than 50 m). The most abundant coccolithophore species was Umbellosphaera irregularis followed by Umbilicosphaera sibogae, Gephyrocapsa oceanica and Emiliania huxleyi. The U. irregularis floral assemblage...

  12. Abstracts of Papers Submitted in 1975 for Publication,

    Science.gov (United States)

    1975-01-01

    Organizado por el Programa de Analisis de Ecosistemas Marinos, de Los Lab- oratorios de Investigacion Ambiental, de la Administracion Nacional Oceanica y...POLITICA DE ADMINISTRACION DE LA ZONE COSTERA DE CHILE The problems arising from the multiple use of the coastal zone, the coastal seas and its resources...LABORATORIOS DE INVESTI- * GACION AMBIENTAL, DE LA ADMINISTRACION NACIONAL OCEANICA Y ATMOSFERICA DEL DEPART- MENTO DE COMERCIO DE LOS ESTADOS UNIDOS DE

  13. Granular flows on erodible layers: type and evolution of flow and deposit structures

    Science.gov (United States)

    Crosta, G.; De Blasio, F.; De Caro, M.; Volpi, G.; Frattini, P.

    2012-04-01

    The interaction of a fast moving landslide mass with the basal layer over which movement takes place has been discussed in previous contributions. Nevertheless, the evolution of the structures within the moving mass and the erodible layer are still to be described in detail (Hungr and Evans, 2004; Crosta et al., 1992, 2006, 2009, 2011; Dufresne et al., 2010; Mangeney et al., 2010) and modeling results (Crosta et al., 2006, 2009, 2011; Mangeney et al., 2010). We present some of the results from a campaign of laboratory experiments aimed at studying the evolution of a granular flow at the impact with and during the successive spreading over a cohesionless erodible layer. We performed these test to study the processes and to collect data and evidences to compare them with the results of numerical simulations and to verify capabilities of numerical codes. The laboratory setup consists of an inclined slope and an horizontal sector where release and transport, and deposition take place, respectively. Materials used for the tests are: a uniform rounded siliceous sand (Hostun sand; 0.125-0.5 mm) commonly adopted in lab tests because free of scale effects, and a gravel made of angular elements (12 mm in ave. size). Both the materials have been tested in dry conditions. Different slope angles have been tested (40, 45, 50, 55, 50, 66°) as well as different thicknesses of the erodible layer (0, 0.5, 1, 2 cm) and volumes of the released material (1.5, 3, 5, 9.6 liters). Tests have been monitored by means of a high speed camera and the pre- and post-failure geometries have been surveyed by means of a laser scanner. Deposit description allowed also the computation of volumes and the characterization of the different structures developed and frozen into the deposit. Experiments allowed us to observe the extreme processes occurring during the movement and the mise en place of the deposits. In particular, we observe the formation of a clear wave-like feature developing during the

  14. Paesaggio, suolo, tempo: la rappresentazione dei tempi geologici nella citta' di Catania

    OpenAIRE

    Ballarin, Matteo; D'Agnone, Nadia

    2014-01-01

    Parlare di tempo geologico è un modo di contestualizzare i processi materiali della terra nella sua storia. La scala dei tempi geologici suddivide la lunga storia della terra in eoni, ere, periodi ed epoche, non omogenei tra loro, ma in relazione l'un l'altro a seconda di ciò che emerge dall'analisi dei dati stratigrafici o dallo studio della stratificazione dei diversi livelli della crosta terrestre. Recentemente negli studi relativi a territorio e paesaggio è stata introdotta...

  15. Vulnerability of marine habitats to the invasive green alga Caulerpa racemosa var. cylindracea within a marine protected area.

    Science.gov (United States)

    Katsanevakis, Stelios; Issaris, Yiannis; Poursanidis, Dimitris; Thessalou-Legaki, Maria

    2010-08-01

    The relative vulnerability of various habitat types to Caulerpa racemosa var. cylindracea invasion was investigated in the National Marine Park of Zakynthos (Ionian Sea, Greece). The density of C. racemosa fronds was modelled with generalized additive models for location, scale and shape (GAMLSS), based on an information theory approach. The species was present in as much as 33% of 748 randomly placed quadrats, which documents its aggressive establishment in the area. The probability of presence of the alga within randomly placed 20 x 20 cm quadrats was 83% on 'matte morte' (zones of fibrous remnants of a former Posidonia oceanica bed), 69% on rocky bottoms, 86% along the margins of P. oceanica meadows, 10% on sandy/muddy substrates, and 6% within P. oceanica meadows. The high frond density on 'matte morte' and rocky bottoms indicates their high vulnerability. The lowest frond density was observed within P. oceanica meadows. However, on the margins of P. oceanica meadows and within gaps in fragmented meadows relative high C. racemosa densities were observed. Such gaps within meadows represent spots of high vulnerability to C. racemosa invasion.

  16. INFLUÊNCIA DO CONTROLE DA ETAPA DE MOLHAGEM DOS GRÃOS NA QUALIDADE MICROBIOLÓGICA DA FARINHA DE TRIGO

    Directory of Open Access Journals (Sweden)

    E. A. LOPES

    2009-01-01

    Full Text Available

    Na fabricação de farinha de trigo, a limpeza inadequada da superfície das roscas molhadora e distribuidora dos grãos permite a formação de uma crosta úmida que pode comprometer a qualidade e segurança microbiológica do produto final. Nesse estudo, realizado em três moinhos brasileiros, avaliou-se os efeitos da adoção de duas medidas de controle na etapa de molhagem dos grãos de trigo, a saber: a remoção diária das crostas e uso de água clorada com 1 ou 2 ppm de cloro livre, b remoção semanal das crostas e uso de água clorada com 100 ppm de cloro livre. Para monitoramento das medidas, foram efetuadas análises de bactérias indicadoras de higiene (aeróbias totais, coliformes totais e fecais e de bolores e leveduras, de Bacillus cereus, Staphylococcus aureus e pesquisa de Salmonella spp. Essas foram realizadas em amostras de crosta e de farinha de trigo, coletadas de 1 até 360 dias após a limpeza das roscas. B. cereus, S. aureus e Salmonella spp não foram detectados em nenhuma das amostras estudadas. Verificou-se que a diminuição do número dos microrganismos indicadores na crosta, em conseqüência da primeira medida de controle, foi insuficiente para produção de farinha de trigo capaz de atender a padrões de qualidade estabelecidos por duas empresas atuantes no setor e também pela legislação vigente (Resolução RDC 12, ANVISA. Por outro lado, análises de verificação, feitas na farinha de trigo, apontaram que a limpeza semanal das roscas e o emprego de água com 100 ppm de cloro livre reduziram acentuadamente o risco de rejeição do produto no mercado.

  17. The detrimental consequences for seagrass of ineffective marine park management related to boat anchoring.

    Science.gov (United States)

    La Manna, G; Donno, Y; Sarà, G; Ceccherelli, G

    2015-01-15

    Posidonia oceanica (L.) Delile meadows are recognized as priority habitat for conservation by the EU Habitats Directive. The La Maddalena Archipelago National Park (Mediterranean Sea) P. oceanica meadow, the dominant coastal habitat of the area, is mostly threatened by boat anchoring. 12 years after the establishment of mooring fields and anchoring restrictions, a study was conducted to measure their effectiveness on the conservation of seagrass and the mitigation of anchoring damage. We found that: (i) the condition of P. oceanica was disturbed, both in the mooring fields and in control locations; (ii) mooring fields and anchoring restrictions did not show to be an efficient system for the protection of seagrass, in fact anchor scars increased after the tourist season; (iii) the mooring systems had an impact on the surrounding area of the meadow, probably due to their misuse. On the basis of these results, management recommendations for marine parks are proposed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Diel oscillation in the optical activity of carotenoids in the absorption spectrum of Nannochloropsis.

    Science.gov (United States)

    Possa, Gabriela C; Santana, Hugo; Brasil, Bruno S A F; Roncaratti, Luiz F

    2017-03-01

    In this paper we show that the absorption spectrum of the microalgae Nannochloropsis oceanica exhibits changes in response to the modulation of incident light. A model was used to analyze the contribution of different active pigments to the total absorption in the photosynthetically active radiation region and suggested consistent diel oscillations in the optical activity of carotenoids.

  19. Seagrass as major source of transparent exopolymer particles in the oligotrophic Mediterranean coast

    KAUST Repository

    Iuculano, Francesca

    2017-01-09

    The role of seagrass, Posidonia oceanica, meadows as a source of transparent exopolymer particles (TEP) to Mediterranean coastal waters was tested by comparing the TEP dynamics in two adjacent coastal waters in the oligotrophic NW Mediterranean Sea, one characterized by oligotrophic open-sea waters and the other accumulating seagrass leaf litter, together with an experimental examination of TEP release by seagrass litter. TEP concentrations ranged from 4.6 µg XG Eq L−1 to 90.6 µg XG Eq L−1, with mean (±SE) values of 38.7 (±2.02) µg XG Eq L−1 in the site devoid of seagrass litter, whereas the coastal beach site accumulating leaf litter had > 10-fold mean TEP concentrations of 487.02 (±72.8) µg XG Eq L−1 . Experimental evaluation confirmed high rates of TEP production by P. oceanica litter, allowing calculations of the associated TEP yield. We demonstrated that P. oceanica is an important source of TEP to the Mediterranean Sea, contributing an estimated 0.10 Tg C as TEP annually. TEP release by P. oceanica seagrass explains the elevated TEP concentration relative to the low chlorophyll a concentration in the Mediterranean Sea.

  20. Physiological and molecular evidence of differential short-term heat tolerance in Mediterranean seagrasses

    Science.gov (United States)

    Marín-Guirao, Lazaro; Ruiz, Juan M.; Dattolo, Emanuela; Garcia-Munoz, Rocio; Procaccini, Gabriele

    2016-06-01

    The increase in extreme heat events associated to global warming threatens seagrass ecosystems, likely by affecting key plant physiological processes such as photosynthesis and respiration. Understanding species’ ability to acclimate to warming is crucial to better predict their future trends. Here, we study tolerance to warming in two key Mediterranean seagrasses, Posidonia oceanica and Cymodocea nodosa. Stress responses of shallow and deep plants were followed during and after short-term heat exposure in mesocosms by coupling photo-physiological measures with analysis of expression of photosynthesis and stress-related genes. Contrasting tolerance and capacity to heat acclimation were shown by shallow and deep P. oceanica ecotypes. While shallow plants acclimated through respiratory homeostasis and activation of photo-protective mechanisms, deep ones experienced photosynthetic injury and impaired carbon balance. This suggests that P. oceanica ecotypes are thermally adapted to local conditions and that Mediterranean warming will likely diversely affect deep and shallow meadow stands. On the other hand, contrasting mechanisms of heat-acclimation were adopted by the two species. P. oceanica regulates photosynthesis and respiration at the level of control plants while C. nodosa balances both processes at enhanced rates. These acclimation discrepancies are discussed in relation to inherent attributes of the two species.

  1. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Some of the coccolithophore species such as E.huxleyi, G.oceanica, Calcidiscus leptoporus and Umbellosphaera tenuis showed signs of dissolution. Volume 122 Issue 2 April 2013 pp 491-501. Provenance and temporal variability of ice rafted debris in the Indian sector of the Southern Ocean during the last 22,000 years.

  2. Retention of lignin in seagrasses: angiosperms that returned to the sea

    NARCIS (Netherlands)

    Klap, V.A.; Hemminga, M.A.; Boon, J.J.

    2000-01-01

    Using Curie-point Pyrolysis Gas Chromatography Mass Spectrometry (Py-GCMS) and Direct Temperature-resolved Mass Spectrometry (DT-MS), lignin was detected in highly purified preparations (Milled Wood Lignin = MWL) of various tissues of the seagrasses Zostera marina and Posidonia oceanica. The results

  3. Alkenone abundance and its relationship to the Coccolithophore Assemblage in Gulf of California

    NARCIS (Netherlands)

    Malinverno, E.; Prahl, F. G.; Popp, B.N.; Ziveri, P.

    2008-01-01

    Profiles of alkenone concentration, the abundance of the calcified alkenone-producing species Emiliania huxleyi and Gephyrocapsa oceanica as well as nutrient and phytoplankton pigment concentrations were measured through the euphotic zone in surface waters of the Gulf of California during cruises in

  4. Influência da carga hídrica na altitude geométrica da estação RBMC de Inconfidentes/MG

    Directory of Open Access Journals (Sweden)

    João Paulo Stach Giacometti

    2017-03-01

    Full Text Available Há diversos métodos para a realização do posicionamento com o GNSS, dentre elas encontra-se o PPP, que na atualidade, é um método de posicionamento, que vislumbra como uma grande potencialidade para obtenção de coordenadas com um alto nível de qualidade, utilizando apenas um receptor. Podendo assim, ser utilizado em aplicações precisas, como a geodinâmica, especificamente em monitoramento da crosta terrestre. O presente trabalho tem como objetivo a análise da influência da carga hídrica na altitude geométrica obtida através do processamento PPP da estação da rede de monitoramento contínuo, denominada MGIN. Nestas análises utilizaram-se dados de temporada de seca e cheia do Rio Mogi-Guaçu e dados de altitude geométrica. A relação entre estes dados mostrou as implicações da carga hídrica sobre as altitudes geométricas, acentuando o soerguimento da crosta. Estes deslocamentos da crosta causados pela influência hídrica, afetam de forma direta as estações GNSS. Isto implica que mesmo com uma distância de 484 metros e uma diferença de nível de 35 metros do rio, o carregamento hídrico influência diretamente na altitude geométrica.

  5. Limites e evolução geodinâmica do Sistema Jaguaribeano, Província Borborema, Nordeste do Brasil

    OpenAIRE

    Cavalcante, José Carvalho

    1999-01-01

    A área envolvida nesta dissertação de mestrado encontra -se situada, geologicamente, no chamado Domínio Setentrional da Província Borborema (P B), Nordeste do Brasil, tendo como marcador meridional a Zona de Cisalhamento Patos. Envolve, preferencialmente, terrenos do Sistema Jaguaribeano, ladeados pelos terrenos ( maciço ) Rio Piranhas, com posicionamentos no leste e sudeste, e Tróia (Tauá) no nordeste. Compreende um espaço de crosta continental dominada por terrenos gnáissico - migmatíticos ...

  6. Monitoramento em longo prazo da contenção vegetativa em talude rodoviário de saprolito de gnaisse em Minas Gerais

    Directory of Open Access Journals (Sweden)

    Rosilene Einloft

    2013-02-01

    Full Text Available A sucessão de eventos após a revegetação de uma área, em geral, não é estudada. Com o passar do tempo, um consórcio vegetal que se apresentou favorável na fase inicial pode não ser adequado no futuro, deixando a área com o solo descoberto e suscetível à ação dos fatores intempéricos. O objetivo deste trabalho foi monitorar características associadas à contenção vegetativa e, em longo prazo, o surgimento de novas formas de cobertura ou exposição do solo em resposta à revegetação com gramíneas e leguminosas em talude rodoviário de declividade acentuada. Após quatro anos, foi observada, nas parcelas experimentais, a presença de novas formas de cobertura ou exposição do solo, denominadas tipologias, como: cobertura de braquiária, leguminosa, capim-gordura, espécies invasoras, biomanta, resíduos em decomposição, crostas microfíticas, crosta física, solo exposto, erosão e afloramento de rochas. Essas tipologias foram quantificadas em dois levantamentos: antes e após o período chuvoso. Foram confeccionados mapas de cobertura para cada parcela experimental e analisadas a dinâmica, distribuição espacial, frequência e competição entre as tipologias encontradas nos dois levantamentos. Das 11 tipologias encontradas, as espécies vegetais e as crostas microfíticas foram as mais importantes no estádio primário da sucessão ecológica, resultando em rápida estabilização e recuperação da superfície degradada e favorecendo o aparecimento de espécies invasoras. A variação sazonal entre os dois levantamentos levou à diminuição da erosão e ao solo exposto, pelo incremento da cobertura vegetal e das crostas microfíticas.

  7. Esporotricose felina com envolvimento humano na cidade de Pelotas, RS, Brasil

    OpenAIRE

    Xavier,Melissa Orzechowski; Nobre,Márcia de Oliveira; Sampaio Junior,Daiser Paulo; Antunes,Tatiana de Ávila; Nascente,Patrícia da Silva; Sória,Flávia Biasoli de Araújo; Meireles,Mário Carlos Araújo

    2004-01-01

    A esporotricose é uma micose subcutânea, causada pelo fungo dimórfico Sporothrix schenckii. O presente estudo descreve a ocorrência de esporotricose felina na cidade de Pelotas (Rio Grande do Sul - Brasil), e a transmissão para um atendente da clínica veterinária, ocasionada pela arranhadura do animal doente. O felino apresentava deformação do espelho nasal e lesões cutâneas, enquanto o humano apresentava uma lesão ulcerada na região metacarpiana dorsal esquerda. Foram colhidas crostas e/ou e...

  8. Epiphytic bryozoans on Neptune grass - a sample-based data set.

    Science.gov (United States)

    Lepoint, Gilles; Heughebaert, André; Michel, Loïc N

    2016-01-01

    The seagrass Posidonia oceanica L. Delile, commonly known as Neptune grass, is an endemic species of the Mediterranean Sea. It hosts a distinctive and diverse epiphytic community, dominated by various macroalgal and animal organisms. Mediterranean bryozoans have been extensively studied but quantitative data assessing temporal and spatial variability have rarely been documented. In Lepoint et al. (2014a, b) occurrence and abundance data of epiphytic bryozoan communities on leaves of Posidonia oceanica inhabiting Revellata Bay (Corsica, Mediterranean Sea) were reported and trophic ecology of Electra posidoniae Gautier assessed. Here, metadata information is provided on the data set discussed in Lepoint et al. (2014a) and published on the GBIF portal as a sampling-event data set: http://ipt.biodiversity.be/resource?r=ulg_bryozoa&v=1.0). The data set is enriched by data concerning species settled on Posidonia scales (dead petiole of Posidonia leaves, remaining after limb abscission).

  9. Macro-grazer herbivory regulates seagrass response to pulse and press nutrient loading.

    Science.gov (United States)

    Ravaglioli, Chiara; Capocchi, Antonella; Fontanini, Debora; Mori, Giovanna; Nuccio, Caterina; Bulleri, Fabio

    2018-02-21

    Coastal ecosystems are exposed to multiple stressors. Predicting their outcomes is complicated by variations in their temporal regimes. Here, by means of a 16-month experiment, we investigated tolerance and resistance traits of Posidonia oceanica to herbivore damage under different regimes of nutrient loading. Chronic and pulse nutrient supply were combined with simulated fish herbivory, treated as a pulse stressor. At ambient nutrient levels, P. oceanica could cope with severe herbivory, likely through an increase in photosynthetic activity. Elevated nutrient levels, regardless of the temporal regime, negatively affected plant growth and increased leaf nutritional quality. This ultimately resulted in a reduction of plant biomass that was particularly severe under chronic fertilization. Our results suggest that both chronic and pulse nutrient loadings increase plant palatability to macro-grazers. Strategies for seagrass management should not be exclusively applied in areas exposed to chronic fertilization since even short-term nutrient pulses could alter seagrass meadows. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Spread of the invasive alga Caulerpa racemosa var. cylindracea (Caulerpales, Chlorophyta along the Mediterranean Coast of the Murcia region (SE Spain

    Directory of Open Access Journals (Sweden)

    Ruiz, J. M.

    2011-06-01

    Full Text Available The aim of this paper was to document the appearance and spread of the green alga Caulerpa racemosa along the coast of Murcia in south-eastern Spain. It was found for the first time in the area in 2005 and over the next two years the number of new sightings increased almost exponentially. In the period 2005-2007 the total surface area colonised by the alga in the region was estimated to be at least 265 ha. Benthic assemblages colonised by the alga were rocky bottoms with photophilic algae, dead P. oceanica rhizomes, infralittoral and circalittoral soft bottoms and maerl beds. No penetration of the alga was observed in P. oceanica meadows, except in one locality. Biometric analysis indicated high vegetative development in the established colonies in comparison to those described in other Mediterranean areas. Rapid spreading dynamics observed in the Murcia region is a potential threat for native benthic communities.

  11. Complete genome sequence of Marinomonas posidonica type strain (IVIA-Po-181T)

    Energy Technology Data Exchange (ETDEWEB)

    Lucas-Elio, Patricia [University of Murcia, Murcia, Spain; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Detter, J C [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Lu, Megan [Los Alamos National Laboratory (LANL); Bruce, David [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Johnston, Andrew W. B. [University of East Anglia, Norwich, United Kingdom; Sanchez-Amat, Antonio [University of Murcia, Murcia, Spain

    2012-01-01

    Marinomonas posidonica IVIA-Po-181T Lucas-Eli o et al. 2011 belongs to the family Oceanospirillaceae within the phylum Proteobacteria. Different species of the genus Marinomonas can be readily isolated from the seagrass Posidonia oceanica. M. posidonica is among the most abundant species of the genus detected in the cultured microbiota of P. oceanica, suggesting a close relationship with this plant, which has a great ecological value in the Mediterranean Sea, covering an estimated surface of 38,000 Km2. Here we describe the genomic features of M. posidonica. The 3,899,940 bp long genome harbors 3,544 pro- tein-coding genes and 107 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  12. Developing Molecular Tools To Genetically Engineer The Microalga Nannochloropsis

    OpenAIRE

    Anley, Kominist Asmamaw

    2015-01-01

    The main objective of this thesis was to develop an efficient transformation protocol for Nannochloropsis oceanica CCMP1779 by biolistic transformation using the linearized pSELECT100 plasmid which confers hygromycin B resistance. In addition the toxicity of several antibiotics for different Nannochloropsis species was determined. Nannochloropsis is the genus of unicellular photosynthetic microalgae in the class of Eustigmatophyceae, which have industrial significance due to their producti...

  13. Variability in the structure of epiphytic assemblages of in relation to human interferences in the Gulf of Gabes, Tunisia

    OpenAIRE

    Ben Brahim, Mounir; Hamza, Asma; Hannachi, Imen; Rebai, Ahmed; Jarboui, Othman; Bouain, Abderrahmen; Aleya, Lotfi

    2010-01-01

    Abstract In this study we evaluate whether the pattern of spatial variability of the macro-epiphytes assemblages of leaves of Posidonia oceanica differed in relation to anthropogenic interference in the Gulf of Gabes (southern coast of Tunisia). A hierarchical sampling design was used to compare epiphytic assemblages at 5m depth in terms of abundance and spatial variability at disturbed and control locations. The results indicate that the biomass and mean percentage cover decreased...

  14. TOXICITY PROPENSITIES OF SOME MARINE AND FRESH-WATERALGAE AS THEIR CHEMICAL DEFENSE

    OpenAIRE

    ORHAN, İlkay; WISESPONGPAND, Puntip; ATICI, Tahir; ŞENER, Bilge

    2003-01-01

    Five species of the marine brown-algae, namely Halopteris scoparia (L.) Sauvagau, Padina vickersiae Hoyt, Dictyota dichotoma (Huds) Lam., Scinaia furcellata L., and Sargassum natans (L.) J. Meyer, a species of the marine green-alga, Ulva lactuca L., a species of the sea grass, Posidonia oceanica L., six species of fresh-water green-algae, namely Vaucheria sessilis (Vauch.) De Candolle, Zygnema pectinatum (Vauch.) C.A. Agardh, Maugeotia sp. (C.A. Agardh) Wittrock, Cladophora fracta (Dilw.) Kti...

  15. Epiphyte presence and seagrass species identity influence rates of herbivory in Mediterranean seagrass meadows

    Science.gov (United States)

    Marco-Méndez, Candela; Ferrero-Vicente, Luis Miguel; Prado, Patricia; Heck, Kenneth L.; Cebrián, Just; Sánchez-Lizaso, Jose Luis

    2015-03-01

    Herbivory on Mediterranean seagrass species is generally low compared to consumption of some other temperate and tropical species of seagrasses. In this study we: (1) investigate the feeding preference of the two dominant Mediterranean seagrass herbivores, the sea urchin Paracentrotus lividus and the fish Sarpa salpa, on Posidonia oceanica and Cymodocea nodosa and (2) elucidate the role of epiphytes in herbivore choices. We assessed consumption rates by tethering seagrass shoots, and preferences by food choice experiments with the following paired combinations: 1) Epiphytized leaves of both C. nodosa vs. P. oceanica (CE vs PE); 2) Non-epiphytized leaves of C. nodosa vs. P. oceanica (CNE vs. PNE); 3) Epiphytized vs non-epiphytized leaves of C. nodosa (CE vs. CNE) and 4) Epiphytized vs non-epiphytized leaves of P. oceanica (PE vs PNE). We found that preference for C. nodosa was weak for S. salpa, but strong for P. lividus, the species responsible for most consumption at our study. Overall both herbivores showed preference for epiphytized leaves. The higher nutritional quality of C. nodosa leaves and epiphytes together with the high coverage and diversity of the epiphyte community found on its leaves help explain the higher levels of herbivory recorded on epiphyted leaves of C. nodosa. Other factors such as seagrass accessibility, herbivore mobility and size, and behavioral responses to predation risks, may also affect the intensity of seagrass herbivory, and studies addressing the interactions with these factors are needed to improve our understanding of the nature, extent and implications of herbivory in coastal ecosystems.

  16. Whole-system metabolism and CO2 fluxes in a Mediterranean Bay dominated by seagrass beds (Palma Bay, NW Mediterranean

    Directory of Open Access Journals (Sweden)

    F. Gazeau

    2005-01-01

    Full Text Available Planktonic and benthic incubations (bare and Posidonia oceanica vegetated sediments were performed at monthly intervals from March 2001 to October 2002 in a seagrass vegetated area of the Bay of Palma (Mallorca, Spain. Results showed a contrast between the planktonic compartment, which was on average near metabolic balance (−4.6±5.9 mmol O2 m-2 d-1 and the benthic compartment, which was autotrophic (17.6±8.5 mmol O2 m-2 d-1. During two cruises in March and June 2002, planktonic and benthic incubations were performed at several stations in the bay to estimate the whole-system metabolism and to examine its relationship with partial pressure of CO2 (pCO2 and apparent oxygen utilisation (AOU spatial patterns. Moreover, during the second cruise, when the residence time of water was long enough, net ecosystem production (NEP estimates based on incubations were compared, over the Posidonia oceanica meadow, to rates derived from dissolved inorganic carbon (DIC and oxygen (O2 mass balance budgets. These budgets provided NEP estimates in fair agreement with those derived from direct metabolic estimates based on incubated samples over the Posidonia oceanica meadow. Whereas the seagrass community was autotrophic, the excess organic carbon production therein could only balance the planktonic heterotrophy in shallow waters relative to the maximum depth of the bay (55 m. This generated a horizontal gradient from autotrophic or balanced communities in the shallow seagrass-covered areas, to strongly heterotrophic communities in deeper areas of the bay. It seems therefore that, on an annual scale in the whole bay, the organic matter production by the Posidonia oceanica may not be sufficient to fully compensate the heterotrophy of the planktonic compartment, which may require external organic carbon inputs, most likely from land.

  17. Dynamics of carbon sources supporting burial in seagrass sediments under increasing anthropogenic pressure

    KAUST Repository

    Mazarrasa, Inés

    2017-03-15

    Seagrass meadows are strong coastal carbon sinks of autochthonous and allochthonous carbon. The aim of this study was to assess the effect of coastal anthropogenic pressure on the variability of carbon sources in seagrass carbon sinks during the last 150 yr. We did so by examining the composition of the sediment organic carbon (Corg) stocks by measuring the δ13Corg signature and C : N ratio in 210Pb dated sediments of 11 Posidonia oceanica seagrass meadows around the Balearic Islands (Spain, Western Mediterranean) under different levels of human pressure. On average, the top meter sediment carbon deposits were mainly (59% ± 12%) composed by P. oceanica derived carbon whereas seston contribution was generally lower (41% ± 8%). The contribution of P. oceanica to the total sediment carbon stock was the highest (∼ 80%) in the most pristine sites whereas the sestonic contribution was the highest (∼ 40–80%) in the meadows located in areas under moderate to very high human pressure. Furthermore, an increase in the contribution of sestonic carbon and a decrease in that of seagrass derived carbon toward present was observed in most of the meadows examined, coincident with the onset of the tourism industry development and coastal urbanization in the region. Our results demonstrate a general increase of total carbon accumulation rate in P. oceanica sediments during the last century, mainly driven by the increase in sestonic Corg carbon burial, which may have important implications in the long-term carbon sink capacity of the seagrass meadows in the region examined.

  18. Evaluation of the potential of 9 Nannochloropsis strains for biodiesel production.

    Science.gov (United States)

    Ma, Yubin; Wang, Zhiyao; Yu, Changjiang; Yin, Yehu; Zhou, Gongke

    2014-09-01

    Nannochloropsis have attracted sustained interest from algal biodiesel researchers due to their high biomass accumulation rate and high lipid content. There are six recognized species in the Nannochloropsis genus that are phylogenetically divided into Nannochloropsis gaditana, Nannochloropsis salina, Nannochloropsis granulata, Nannochloropsis limnetica, Nannochloropsis oceanica and Nannochloropsis oculata. In this study, the potential of 9 Nannochloropsis species from the 6 genus for biodiesel production was evaluated by determining their growth rate, biomass accumulation, lipid productivity, lipid composition, fatty acid profiles and biodiesel properties. The results showed that the best strain was N. oceanica IMET1, with lipid productivity of 158.76 ± 13.83 mg L(-1)day(-1), TAG production of 1.67 ± 0.20 g/L, favorable fatty acid profiles of C16-C18 (56.62 ± 1.96%) as well as suitable biodiesel properties of higher cetane number (54.61 ± 0.25), lower iodine number (104.85 ± 2.80 g I2/100g) and relative low cloud point (3.45 ± 0.50°C). N. oceanica IMET1 could be consider as valuable feedstock for microalgal biodiesel production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Distribution of coccolithophores as a potential proxy in paleoceanography: The case of the Oman Sea monsoonal pattern

    Directory of Open Access Journals (Sweden)

    Mojtahedin Elham

    2015-02-01

    Full Text Available High abundances of coccoliths have been observed in surface sediment samples from near the coasts of the Oman Sea in February 2011. At the end of the NE monsoon, the locally observed high Gephyrocapsa oceanica production is hypothesized to respond to local injections of nutrient-rich deep water into the surface water due to sea-surface cooling leading to convection. The most abundant coccolithophore species are G. oceanica followed by Emiliania huxleyi, Helicosphaera carteri, Calcidiscus leptoporus. Some species, such as Gephyrocapsa muellerae, Gephyrocapsa ericsonii, Umbilicosphaera sibogae, Umbellosphaera tenuis and Florisphaera profunda, are rare. The G. oceanica suggested a prevalence of upwelling conditions or high supply of nutrients in the Oman Sea (especially West Jask at the end of the NE monsoon. E. huxleyi showed low relative abundances at the end of the NE monsoon. Due to the location of the Oman Sea in low latitudes with high temperatures, we have observed low abundances of G. muellerae in the study area. Additionally, we have identified low abundances of G. ericsonii at the end of the NE monsoon. Helicosphaera carteri showed a clear negative response with decreasing amounts (relative abundances at the end of the NE monsoon. C. leptoporus, U. sibogae and U. tenuis have very low relative abundances in the NE monsoon and declined extremely at the end of the NE monsoon. F. profunda, which is known to inhabit the lower photic zone (<100 m depht was rarely observed in the samples.

  20. Baseline trace metals in seagrass, algae, and mollusks in a southern Tyrrhenian ecosystem (Linosa Island, Sicily).

    Science.gov (United States)

    Conti, Marcelo Enrique; Bocca, Beatrice; Iacobucci, Marta; Finoia, Maria Grazia; Mecozzi, Mauro; Pino, Anna; Alimonti, Alessandro

    2010-01-01

    Trace elements were analyzed in organisms collected at five sampling stations along coastal areas of Linosa Island, Sicily (southern Tyrrhenian Sea, Italy). Concentrations of Cd, Cr, Cu, Pb, and Zn were measured in Posidonia oceanica L. Delile tissues, the two brown algae Padina pavonica (L.) Thivy and Cystoseira sp., and the two gastropod mollusks Monodonta turbinata Born and Patella caerulea L. Seawater samples were also collected at each site to assess soluble metal concentrations and to gain relevant information on their bioaccumulation ability. Data were processed by multivariate techniques, such as principal component analysis (PCA) and linear discriminant analysis on PCA factors. The scoreplots obtained showed that the pollutant distribution is more significantly correlated with species than with sites. For seaweeds, P. oceanica was associated with higher Cd, Cu, and Zn levels; Padina species had higher Cr concentrations, and Cystoseira had higher Pb levels. For mollusks, Monodonta species had high concentrations of Cu and Cr and Patella species were associated with Cd. Some general metal bioaccumulation patterns are described but no one sampling site was more contaminated than the others. The hypothesis of Linosa island serving as a reference ecosystem for baseline trace metal levels in southern Tyrrhenian areas is indeed supported by the statistical comparison among other southern Tyrrhenian ecosystems performed with Kruskall Wallis and Mann-Whitney tests. For P. oceanica leaves, P. pavonica, M. turbinata, and P. caerulea, this study confirms their usefulness as possible cosmopolitan biomonitors of trace metals in marine Mediterranean areas.

  1. The trace metals accumulation in marine organisms of the southeastern Adriatic coast, Montenegro

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    Joksimovic Danijela

    2012-01-01

    Full Text Available The concentration and accumulation of trace metals (Co, Ni, As, Cd, Pb and Hg were measured in sea water, sediments and marine organisms in the coastline of the Montenegro. The obtained results of trace metals in seagrass and mussels were compared with those found in the water column and sediment. Sampling was performed in the fall of 2005 at five locations in the Montenegrin coastline, Sveta Stasija, Herceg Novi, Zanjice, Budva and Bar, which present different levels and sources of human impact. The heavy metals analyses in seawater, sediment, P. oceanica and M. galloprovincialis identified the harbor of Bar as the most Hg-contaminated site, Zanjice as the most As contaminated and Sveta Stasija as the most Pb-contaminated areas of the Montenegrin coastal area. This study showed that P. oceanica may have a greater bioaccumulation capacity than M. galloprovincialis for the considered metals, except for As and Hg, and both organisms may reflect contamination in the water column and in the sediment. For the first time, seagrass P. oceanica and M. galloprovincialis were employed as metal bioindicators for the southeastern Adriatic. The results of this study could serve as a baseline in the future for the assessment of anthropogenic effects in this marine ecosystem.

  2. Effects of light-emitting diode (LED) with a mixture of wavelengths on the growth and lipid content of microalgae.

    Science.gov (United States)

    Ra, Chae Hun; Sirisuk, Phunlap; Jung, Jang-Hyun; Jeong, Gwi-Taek; Kim, Sung-Koo

    2018-04-01

    Integrations of two-phase culture for cell growth and lipid accumulation using mixed LED and green LED wavelengths were evaluated with the microalgae, Phaeodactylum tricornutum, Isochrysis galbana, Nannochloropsis salina, and Nannochloropsis oceanica. Among the single and mixed LED wavelengths, mixed LED produced higher biomass of the four microalgae, reaching 1.03 g DCW/L I. galbana, followed by 0.95 g DCW/L P. tricornutum, 0.85 g DCW/L N. salina, and 0.62 g DCW/L N. oceanica than single LED or fluorescent lights at day 10. Binary combination of blue and red LEDs could produce the high biomass and photosynthetic pigments in the four microalgae. The highest lipid accumulation during second phase with the exposure to green LED wavelengths was 56.0% for P. tricornutum, 55.2% for I. galbana, 53.0% for N. salina, and 51.0% for N. oceanica. The major fatty acid in the four microalgae was palmitic acid (C16:0) accounting for 38.3-47.3% (w/w) of the total fatty acid content.

  3. Changes in seagrass polychaete assemblages after invasion by Caulerpa racemosa var. cylindracea (Chlorophyta: Caulerpales: community structure, trophic guilds and taxonomic distinctness

    Directory of Open Access Journals (Sweden)

    Antonio Box

    2010-06-01

    Full Text Available A two-year study focusing on the associated polychaete assemblages revealed that the degradation of the Posidonia oceanica seagrass meadows, together with the colonisation of rhizomes by invasive Caulerpa racemosa in the Balearic Islands, have produced important changes in the ecosystem functioning, and have therefore affected the benthic faunal communities. The highest abundance and number of species occurred in C. racemosa from August to December. The species composition of the polychaete assemblage in C. racemosa is similar to that of P. oceanica but abundances of shared species differ between Caulerpa and Posidonia. Abundance, number of species and diversity were positively correlated with C. racemosa biomass. The spatial complexity provided by the network of C. racemosa fronds and stolons seemed to combine with that of the remaining seagrass mat to support a well developed polychaete assemblage. Although invaded meadows harboured significantly modified polychaete assemblages when compared with living P. oceanica meadows, the main impacts seem to be non-harmful (i.e. increased abundance and number of species and mainly affect their seasonal patterns, which is a direct consequence of the corresponding biomass seasonality of C. racemosa.

  4. Global warming enhances sulphide stress in a key seagrass species (NW Mediterranean).

    Science.gov (United States)

    García, Rosa; Holmer, Marianne; Duarte, Carlos M; Marbà, Núria

    2013-12-01

    The build-up of sulphide concentrations in sediments, resulting from high inputs of organic matter and the mineralization through sulphate reduction, can be lethal to the benthos. Sulphate reduction is temperature dependent, thus global warming may contribute to even higher sulphide concentrations and benthos mortality. The seagrass Posidonia oceanica is very sensitive to sulphide stress. Hence, if concentrations build up with global warming, this key Mediterranean species could be seriously endangered. An 8-year monitoring of daily seawater temperature, the sulphur isotopic signatures of water (δ(34)S(water)), sediment (δ(34)SCRS ) and P. oceanica leaf tissue (δ(34)S(leaves)), along with total sulphur in leaves (TS(leaves)) and annual net population growth along the coast of the Balearic archipelago (Western Mediterranean) allowed us to determine if warming triggers P. oceanica sulphide stress and constrains seagrass survival. From the isotopic S signatures, we estimated sulphide intrusion into the leaves (F(sulphide)) and sulphur incorporation into the leaves from sedimentary sulphides (SS(leaves)). We observed lower δ(34)S(leaves), higher F(sulphide) and SS(leaves) coinciding with a 6-year period when two heat waves were recorded. Warming triggered sulphide stress as evidenced by the negative temperature dependence of δ(34)S(leaves) and the positive one of F(sulphide), TS(leaves) and SS(leaves). Lower P. oceanica net population growth rates were directly related to higher contents of TS(leaves). At equivalent annual maximum sea surface water temperature (SST(max)), deep meadows were less affected by sulphide intrusion than shallow ones. Thus, water depth acts as a protecting mechanism against sulphide intrusion. However, water depth would be insufficient to buffer seagrass sulphide stress triggered by Mediterranean seawater summer temperatures projected for the end of the 21st century even under scenarios of moderate greenhouse gas emissions, A1B

  5. Estudo da emanação de radonio em amostras de concreto com composições diferentes

    OpenAIRE

    Aline Katiuscia Mateus Joaquim Burke

    2002-01-01

    Resumo: O radônio-222 é um gás nobre e radioativo presente na cadeia de decaimento do urânio238. Os componentes do concreto (cimento e agregados) têm suas matérias-primas extraídas da crosta terrestre que contêm o urânio como impureza. O 238U presente nesses componentes irá decair segundo a sua série radioativa até o 206Pb, passando pelo radônio que pode difundir-se para o interior das edificações. A emanação de 222Rn proveniente do concreto depende de dois fatores: do teor de 226Ra e do comp...

  6. Amianto: a bioética entre o custo e a toxicidade

    OpenAIRE

    Sileno Corrêa Brum; Bianca de Almeida; Edson da Silva Pelosi; Jonas Pacheco; Maria das Graças Ávila Guimarães

    2016-01-01

    O amianto ou asbesto é resistente a ataques químicos de ácidos e álcalis e bacteriológicos, incapaz de combustão, de alto isolamento térmico e durabilidade, encontrado na crosta terrestre. Parte da Europa proibiu o seu uso. O Brasil está entre os maiores produtores e consumidores mundiais. Para a relação entre o amianto e a saúde humana há relativo consenso sobre a toxicidade do amianto. A contaminação ocorre pela: exposição às fibras de amianto em residências próximas às fábricas, minerações...

  7. Surface modification of a granite building stone in central Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    José A. Baptista-Neto

    2006-06-01

    Full Text Available In order to evaluate environmental controls on the soiling formation and decay of building stones a set of mapping and physical and chemical analyses were carried out on granite from a historical church in the polluted centre of Rio de Janeiro. These techniques highlight the increasing of threatening damage on generally perceived as a durable building material, caused by granular disaggregation and contour scaling in areas close to ground level. Mapping also indicated the formation of black crusts over entire building façades, concentrated on areas sheltered from rain-wash. Analyses demonstrated the influence of marine aerosols, rock and mortar composition and mostly of the atmospheric pollutants on the decay and soiling of the granite. Much of the decay is associated specifically with the presence of halite (NaCl and gypsum (CaS04.2H2O. The fact that black, gypsum crusts are able to develop over entire façades in a humid subtropical environment is testimony to the high levels of local pollution, especially particulate deposition. Reduced rainwash, in sheltered micro-environments of narrow, canyon-like streets, overcomes the gypsum tendency to bewashed away from buildings façades. These observations further highlight that decay processes are primarily controlled by microclimatic conditions.Com o objetivo de se avaliar os controles ambientais na formação de crostas e deterioração de rochas ornamentais em fachadas de prédios históricos, uma série de mapeamentos e análises fisicas e químicas foram realizados em granitos da fachada de uma igreja histórica numa área poluída no centro da cidade do Rio de Janeiro. Estas técnicas destacam a ameaça crescente dos danos causados pela desagregação granular e esfoliação da rocha que é fortemente percebido por se tratar de um material de alta durabilidade usado na fachada do prédio em áreaslocalizadas ao nível do chão. O exercício de mapeamento possibilitou a demarcação e observa

  8. Evolução paleoproterozoica do Cinturão Mineiro: geocronologia U-Pb, isótopos de Nd-Hf-Sr e geoquímica de rochas plutônicas

    OpenAIRE

    Natali da Silva Barbosa

    2015-01-01

    O cinturão Mineiro corresponde a um extenso terreno juvenil composto por metagranitoides e sequências supracrustais que compõem a orogenia acrescionária Minas na porção meridional do cráton do São Francisco. A produção da crosta continental ocorreu a partir de 3 arcos magmáticos desde 2,47 Ga, com duração de ca. 380 Ma. Sendo que o arco mais jovem (2,17-2,10 Ga) causou a remobilização de boa parte do antepaís arqueano, conforme dados da literatura. Esta Tese apresenta e interpreta novos dados...

  9. Diagnóstico laboratorial de varíola: III - resultados do terceiro ano de atividades

    Directory of Open Access Journals (Sweden)

    J. A. Mesquita

    1971-12-01

    Full Text Available Os autores apresentam os resultados obtidos no terceiro ano de atividades do laboratório de Diagnóstico de Varíola, no Instituto Presidente Castello Bran-co, da Fundação Instituto Oswaldo Crus, no Rio de Janeiro. O exame de 82 espécimens de crosta e de 70 de liquido vesicular/pustular forneceu respectivamente 14 e 16 nmostras de vírus da varíola (Tabela 1. Oriundos do Estado da Guanabara, foram examinados 33 espécimens e iso-ladas 23 amostras de vírus variólico (Tabela 2. Foram comparadas as vacinas antivariólicas 'preparadas em ovos embriona- dos e as preparadas em pele de vitelos, tendo sido consideradas equivalentes nas condições descritas. O laboratório continua a receber regularmente mais espécimens para diagnóstico.

  10. Assessment Of Slope Covers Vulnerability To Shallow Mass Movements Using Sinmap

    Science.gov (United States)

    Demczuk, Piotr; Zydroń, Tymoteusz; Franczak, Łukasz

    2014-06-01

    In Flysch Carpathians mass movements are a significant factor that causes changes in the morphology of slopes and, in many cases, causes also economic damage. A complicated geological structure of the area, high height differences and high rainfall, which is the main factor initiating mass movements, are mainly listed among the basic conditions for such type of processes to occur. Infiltration of rainfall in the soil profile can lead to a loss of stability in two ways (Crosta 1998). Infiltration process can cause an increase in the groundwater level when there are low intensity rainfalls. High intensity rainfalls can cause creating of perched water table in the area of moving quench front, therefore in many publications in the field of geotechnics and engineering geology (among others: Crosta 1998; Li et al. 2006; Rahardjo et al. 2007, 2010; Tu et al. 2009) assessment of vulnerability of slope covers to mass movements does not focus only on the strength parameters of the soil, but it also takes infiltration of rainfall into consideration. Because of a recent development of spatial information systems, slope stability evaluation is more often done in relation to large areas, comprising river basins or even regions (Montgomery and Dietrich 1994; Morrissey et al. 2001; Meisina and Scarabelli 2007). One of the generally used in GIS environment phy sical model of water distribution in the soil profile that allows to determine slope stability is SINMAP (Pack et al. 1999). An attempt to do a preliminary assessment of vulnerability of surface slope covers from the area of Nowy Wiśnicz commune to mass movements using SINMAP model was made and presented in the paper, along with the verification of modeling results with actual existing landslides

  11. Dermatophytosis caused by Microsporum canis and Microsporum gypseum in free-living Bradypus variegatus (Schiz, 1825 in the state of Pernambuco, Brazil Dermatofitose por Microsporum canis e Microsporum gypseum em Bradypus variegatus (Schiz, 1825 de vida livre no estado de Pernambuco, Brasil

    Directory of Open Access Journals (Sweden)

    Gileno Antônio Araújo Xavier

    2008-09-01

    Full Text Available Three cases of dermatophytosis in free living brown-throated three-toed sloths (Bradypus variegatus in the Zona da Mata, North of Pernambuco State, Brazil, were studied. Two animals presented areas of alopecia on the pelvic member and thorax and one animal on the pelvic member only. The three animals presented scabs. Hair and scabs samples were submitted to microscopical examination after treatment with a 30 % KOH and cultivated in Mycosel Agar. The direct examination indicated the presence of arthrospores in the hair. Colonies grown after seven days of culture were confirmed as Microsporum based on examination of the structure of the macroconidia. This is the first observation of dermatophytosis caused by Microsporum canis and Microsporum gypseum in free living sloths in the State of Pernambuco.Foram estudados três casos de dermatofitose em preguiças-de-garganta-marrom (Bradypus variegatus de vida livre na Zona da Mata, Norte do Estado de Pernambuco, Brasil. Dois animais apresentavam áreas de alopecia nos membros pélvicos e torácicos e um apenas no membro pélvico. Em todos os animais foi observada a presença de crostas. As amostras de pêlos e crostas foram submetidas ao exame microscópico direto com KOH a 30% e cultivo em Ágar Mycosel. Ao exame direto foram observados artrosporos nos pêlos e sete dias após o cultivo foram observadas colônias sugestivas do gênero Microsporum, confirmadas através da observação da estrutura dos macroconídeos. Trata-se do primeiro relato de ocorrência de dermatofitose por Microsporum canis e Microsporum gypseum em preguiças de vida livre no Estado de Pernambuco.

  12. Perdas de solo, nutrientes, matéria orgânica e efeitos microestruturais em Argissolo Vermelho-Amarelo sob chuva simulada

    Directory of Open Access Journals (Sweden)

    Schaefer Carlos Ernesto Reynaud

    2002-01-01

    Full Text Available Estudo experimental com simulador de chuva foi conduzido em área de Argissolo Vermelho-Amarelo caulinítico, em Viçosa, MG, com intensidade de precipitação de 60 mm h-1 e seis aplicações sucessivas, espaçadas de 12 horas. Caracterizou-se a evolução do selamento superficial e das perdas de nutrientes, solo e matéria orgânica em razão de diferentes porcentagens de cobertura (0, 20, 40, 80 e 100% em cultivo morro abaixo (declividade média de 9,5%, em resposta à energia cinética decorrente da precipitação. As perdas totais de solo foram superiores a 11 t ha-1 nos tratamentos com porcentagem de cobertura entre 0 e 40%, reduzindo-se a pouco mais de 5 t ha-1 com 80% até zero no tratamento 100% coberto com Bidim. As perdas de nutrientes seguiram a ordem Ca>Mg>K>P e foram correlacionadas às perdas de matéria orgânica. O fracionamento de substâncias húmicas revelou a concentração residual de humina e perdas seletivas de formas mais solúveis (ácidos fúlvicos com a enxurrada. A erosão causou heterogeneidade entre a parte superior e inferior das parcelas experimentais. A macroporosidade entre 10 e 20 cm é maior na parte superior da parcela, sugerindo a migração de argila dispersa e entupimento de macroporos nas condições de chuva simulada. Excetuando-se o tratamento com 100% de cobertura, todos os demais evidenciam crosta deposicional. Nos tratamentos com maior exposição houve presença de crosta erosional, ao fim do teste de campo.

  13. Millennial scale impact on the marine biogeochemical cycle of mercury from early mining on the Iberian Peninsula

    Science.gov (United States)

    Serrano, O.; Martínez-Cortizas, A.; Mateo, M. A.; Biester, H.; Bindler, R.

    2013-01-01

    The high-resolution mercury record of a Posidonia oceanica mat in the northwest Mediterranean provides an unprecedented testimony of changes in environmental mercury (Hg) loading to the coastal marine environment over the past 4315 yr BP. The period reconstructed made it possible to establish tentative preanthropogenic background Hg levels for the area (6.8 ± 1.5 ng g-1 in bulk sediments). A small, but significant, anthropogenic Hg increase was identifiable by 2500 yr BP, in agreement with the beginning of intense mining in Spain. Changes in the record suggest four major periods of anthropogenic Hg pollution inputs to the Mediterranean: first, during the Roman Empire (2100-1800 yr BP); second, in the Late Middle Ages (970-650 yr BP); third, in the modern historical era (530-380 yr BP); and fourth, in the industrial period (last 250 years), with Hg concentrations two-, four-, five-, and tenfold higher than background concentrations, respectively. Hg from anthropogenic sources has dominated during the last millennium (increase from 12 to 100 ng g-1), which can be related to the widespread historical exploitation of ore resources on the Iberian Peninsula. The chronology of Hg concentrations in the mat archive, together with other Hg pollution records from the Iberian Peninsula, suggests regional-scale Hg transport and deposition and shows earlier marine Hg pollution than elsewhere in Europe. Moreover, the mat also records a higher number of historic contamination phases, in comparison with other natural archives, probably due to the fact that the bioaccumulating capacity of P. oceanica magnify environmental changes in Hg concentrations. In this study, we demonstrate the uniqueness of P. oceanica meadows as a long-term archive recording trends in Hg abundance in the marine coastal environment, as well as its potential role in the Mediterranean as a long-term Hg sink.

  14. Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

    Science.gov (United States)

    Faucher, Giulia; Hoffmann, Linn; Bach, Lennart T.; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

    2017-07-01

    The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae), intermediate- (E. huxleyi and G. oceanica) and least-tolerant (C. pelagicus) taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

  15. Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917–2004

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    M. Grelaud

    2009-10-01

    Full Text Available The varved sedimentary AD 1917–2004 record from the depositional center of the Santa Barbara Basin (SBB, California was analyzed with monthly to triannual resolution to yield relative abundances of six coccolithophore species representing at least 96% of the coccolithophore assemblage. Seasonal/annual relative abundances respond to climatic and surface hydrographic conditions in the SBB, whereby (i the three species G. oceanica, H. carteri and F. profunda are characteristic of the strength of the northward flowing warm California Counter Current, (ii the two species G. ericsonii and G. muellerae are associated with the cold equatorward flowing California Current, (iii and E. huxleyi appears to be endemic to the SBB. Spectral analyses on relative abundances of these species show that all are influenced by the El Niño Southern Oscillation (ENSO and/or by the Pacific Decadal Oscillation (PDO. Increased relative abundances of G. oceanica and H. carteri are associated with warm ENSO events, G. muellerae responds to warm PDO events and the abundance of G. ericsonii increases during cold PDO events. Morphometric parameters measured on E. huxleyi, G. muellerae and G. oceanica indicate increasing coccolithophore shell carbonate mass from ~1917 until 2004 concomitant with rising pCO2 and sea surface temperature in the region of the SBB.

  16. The Ecosystem Approach for the design of compensation and mitigation measures on coastal marine environment: the case study of Civitavecchia harbour

    Science.gov (United States)

    Marcelli, Marco; Scanu, Sergio; Piermattei, Viviana; Bonamano, Simone; Mancini, Emanuele; Madonia, Alice

    2017-04-01

    The coastal marine domain is characterized by physical and ecological conditions that favour and determine a spatial overlap between the different uses of natural resources. In this context, the coastal area of Civitavecchia houses important biodiversity hotspots as well as multiple human activities, being affected by potential conflicts. In particular, the works of expansion scheduled for the Port of Civitavecchia, one of the largest in Europe in terms of cruise and ferry traffic, could impact on two Sites of Community Importance (IT6000005 and IT6000006), for the presence of priority habitats (Posidonia oceanica meadows and reefs of rocky substrates and biogenic concretions) and species (Pinna nobilis and Corallium rubrum) according to Habitat Directive 92/43/EEC. Considering that the Natural Capital analysis is indeed a valid emerging management tool for marine conflicts resolution (Maritime Spatial Planning Directive 2014/89 / EU - MSP), this study aims to propose a methodology to quantify the compensation and mitigation measures, evaluating the ecosystem services of priority habitats and species impacted by harbour expansion activities. To evaluate the ecosystem services the benthic biocoenoses, analyzed in the study area over the past 35 years, were chosen as reference spatial unit. We present the results of the economic evaluation of the benefits produced by Posidonia oceanica meadows (Habitat 1120), and Reef (Habitat 1170). For Posidonia oceanica meadows we computed benefits in relation to carbon sequestration, erosion control, bioremediation, food production, recreational potential and O2 supply, for Reefs using the method proposed by De Groot et al. 2012. The results of the economic assessment of ecosystem services for Habitat 1120 are in agreement with literature data. The results for the services related to the Habitat 1120 are significantly lower because of the influence of the ongoing impacts of human activity. This study allowed to define a specific

  17. Climate change and Mediterranean seagrass meadows: a synopsis for environmental managers

    Directory of Open Access Journals (Sweden)

    G. PERGENT

    2014-02-01

    Full Text Available This synopsis focuses on the effects of climate change on Mediterranean seagrasses, and associated communities, and on the contribution of the main species, Posidonia oceanica, to the mitigation of climate change effects through its role of sequestering carbon dioxide. Whilst the regression of seagrass meadows is well documented, generally linked to anthropogenic pressures, global warming could be a cause of new significant regressions, notably linked to the introduction of exotic species, the rise of Sea-Surface Temperature (SST, and relative sea level. Seagrass communities could also be affected by climate change through the replacement of seagrass species having high structural complexity by species of lower complexity and even by opportunistic introduced species. Although it is currently very difficult to predict the consequences of these alterations and their cascade effects, two main conflicting trends in the functioning of seagrass ecosystems that could occur are acceleration of the herbivore pathway or of the detritivore pathway. The mean net primary production of the dominant species, Posidonia oceanica, is relatively high and can be estimated to range between 92.5 to 144.7 g C m-2 a-1. Around 27% of the total carbon fixed by this species enters the sedimentary pathway leading to formation, over millennia, of highly organic deposits rich in refractory carbon. At the Mediterranean scale, the sequestration rate might reach 1.09 Tg C a-1. The amount of this stored carbon is estimated to range from 71 to 273 kg C m-2, which when considered at the Mediterranean scale would represent 11 to 42% of the CO2 emissions produced by Mediterranean countries since the beginning of the Industrial Revolution. The greatest value of the P. oceanica ecosystem, in the context of mitigation of global climate change, is linked to this vast long-term carbon stock accumulated over the millennia, and therefore, efforts should be focused on preserving the

  18. Impact of trace metal concentrations on coccolithophore growth and morphology: species-specific responses in past and present ocean

    Science.gov (United States)

    Faucher, Giulia; Hoffmann, Linn; Bach, Lennart Thomas; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

    2017-04-01

    The Cretaceous witnessed intervals of profound perturbation named "Oceanic Anoxic Events (OAEs)" characterized by volcanic injection of large amounts of CO2, ocean anoxia, eutrophication, and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a number of nannofossil species. To detect the cause/s of such changes in the fossil record is challenging. Evidence of a correspondence between intervals of high trace metals concentrations and nannofossil dwarfism may be suggestive for a negative effect of these elements on nannoplankton biocalcification process. In order to verify the hypothesis that anomalously high quantities of essential and/or toxic metals were the cause of coccolith dwarfism, we explored the toxicities of a mixture of trace metals on four living coccolithophores species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The trace metals tested were chosen based upon concentration peaks identified in the geological record and upon known trace metal interaction with living coccolithophores algae. Our results demonstrate a species-specific response to trace metal enrichment in living coccolithophores: E. huxleyi, G. oceanica and C. pelagicus showed a decrease in their growth rate with progressively and exponentially increased trace metal concentrations, while P. carterae is unresponsive to trace metal content. Furthermore, E. huxleyi, G. oceanica and C. pelagicus evidenced a decrease in the cell diameter. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccolith of G. oceanica showed a decrease in size only at the highest trace metal concentrations tested. P. carterae size was unresponsive for changing trace metal concentration. Our results on living coccolithophore algae, demonstrate that elevated trace metal concentrations not only affect growth but also coccolith size and/or weight and that

  19. Methylthio-Aspochalasins from a Marine-Derived Fungus Aspergillus sp.

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2014-09-01

    Full Text Available Two novel aspochalasins, 20-β-methylthio-aspochalsin Q (named as aspochalasin V, (1 and aspochalasin W (2, were isolated from culture broth of Aspergillus sp., which was found in the gut of a marine isopod Ligia oceanica. The structures were determined on the basis of NMR and mass spectral data analysis. This is the first report about methylthio-substituted aspochalasin derivatives. Cytotoxicity against the prostate cancer PC3 cell line and HCT116 cell line was assayed using the MTT method. Apochalasin V showed moderate activity at IC50 values of 30.4 and 39.2 μM, respectively.

  20. Much damage for little advantage: Field studies and morphodynamic modelling highlight the environmental impact of an apparently minor coastal mismanagement

    Science.gov (United States)

    Lasagna, Roberta; Montefalcone, Monica; Albertelli, Giancarlo; Corradi, Nicola; Ferrari, Marco; Morri, Carla; Bianchi, Carlo Nike

    2011-09-01

    While coastal management activities have long been known to exert a strong influence on the health of marine ecosystems, neither scientists nor administrators have realized that small interventions may lead to disproportionately larger impacts. This study investigated the broad and long-lasting environmental consequences of the construction of an ill-planned, although small (only 12 m long) jetty for pleasure crafts on the hydrodynamic conditions and on the meadow of the seagrass Posidonia oceanica of an embayed cove in the Ligurian Sea (NW Mediterranean). There, P. oceanica used to develop on a high (>1.5 m) matte (a lignified terrace causing seafloor elevation) in which the leaves reach the surface and form a compact natural barrier to waves in front of the beach. Such a so-called 'fringing reef' of P. oceanica is today recognized of high ecological value and specific conservation efforts are required. The construction of the jetty implied the cutting of the matte, which directly destroyed part of the fringing reef. In addition, meadow mapping and sedimentological analyses coupled with morphodynamic modelling showed that the ecosystem of the whole cove had been greatly altered by the jetty. We used the geometric planform approach, a proper tool in the study of headland-controlled embayment, both to characterise the present situation of Prelo cove and to simulate the original one, before the jetty was built. In the long term, such a small jetty completely altered the configuration and the hydrodynamic conditions of the whole cove, splitting the original pocket beach into two smaller ones and creating strong rip-currents flowing seaward along the jetty. These rip-currents enhanced erosion of residual shallow portions of the meadow and further modified the sedimentary fluxes in shallow waters. A century after the construction of the jetty, an irreversible environmental damage has occurred, as the slow growing rate of P. oceanica implies that the high matte terrace

  1. New host and distributional records for Cryptosporidium sp. (Apicomplexa: Cryptosporidiidae) from lizards (Sauria: Gekkonidae, Scincidae) from the Cook Islands and Vanuatu, South Pacific

    Science.gov (United States)

    McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.

    2013-01-01

    Between 1991 and 1993, 295 lizards, comprising 21 species in 2 families (Gekkonidae, Scincidae) from the Cook Islands, Fiji, Palau, Takapoto, and Vanuatu in the South Pacific, were examined for Cryptosporidium oocysts. Only 6 lizards (2%) were found to be passing Cryptosporidium oocysts in their feces, including 2 of 30 (7%) Oceania geckos, Gehyra oceanica, from Rarotonga, Cook Islands, and 4 of 26 (15%) Pacific blue-tailed skinks, Emoia caeruleocauda, from Efate Island, Vanuatu. This represents the largest survey for Cryptosporidium in Pacific island lizards, and we document 2 new host and 2 new locality records for this parasite genus.

  2. Is the endemic Maltese Top-shell Gibbula nivosa extinct?

    OpenAIRE

    Schembri, Patrick J.; Borg, Joseph A.; Deidun, Alan; Knittweis, Leyla; Mellado Lopez, T.

    2007-01-01

    The trochid gastropod Gibbula nivosa, endemic to the Maltese Islands, has recently only been found in two Maltese bays, where it occurred on seagrass leaves and under stones at depths of 1-4m. Intensive sampling of Cymodocea nodosa and Posidonia oceanica meadows, sediment and pebbles at depths of 2-12m, carried out in 2000 and 2002, resulted only in empty shells but no live animals, suggesting that the species is extinct from these localities where previously good populations were found. Howe...

  3. Predicting the reproduction strategies of several microalgae through their genome sequences

    Science.gov (United States)

    Guo, Li; Yang, Guanpin

    2015-06-01

    Documenting the sex and sexual reproduction of the microalgae is very difficult, as most of the results are based on the microscopic observation that can be heavily influenced by genetic, physiological and environmental conditions. Understanding the reproduction strategy of some microalgae is required to breed them in large scale culture industry. Instead of direct observation of sex and sexual reproduction under microscope, the whole set or the majority of core meiosis genes may evidence the sex and sexual reproduction in the unicellular algae, as the meiosis is necessary for maintaining the genomic stability and the advantages of genetic recombination. So far, the available genome sequences and bioinformatic tools (in this study, homolog searching and phylogenetic analysis) allow us to propose that at least 20 core meiosis genes (among them ≥6 must be meiosis specific) are enough for an alga to maintain its sexual reproduction. According to this assumption and the genome sequences, it is possible that sexual reproduction was carried out by Micromonas pusilla and Cyanidioschyzon merolae, while asexual reproduction was adopted by Bigelowiella natans, Guillardia theta, Nannochloropsis gaditana, N. oceanica, Chlorella variablis, Phaeodactylum tricornutum and Thalassiosira pseudonana. This understanding will facilitate the breeding trials of some economic microalgae ( e.g., N. gaditana, N. oceanica, C. variablis and P. tricornutum). However, the reproduction strategies of these microalgae need to be proved by further biological experiments.

  4. Coccolithophorid algae culture in closed photobioreactors.

    Science.gov (United States)

    Moheimani, Navid R; Isdepsky, Andreas; Lisec, Jan; Raes, Eric; Borowitzka, Michael A

    2011-09-01

    The feasibility of growth, calcium carbonate and lipid production of the coccolithophorid algae (Prymnesiophyceae), Pleurochrysis carterae, Emiliania huxleyi, and Gephyrocapsa oceanica, was investigated in plate, carboy, airlift, and tubular photobioreactors. The plate photobioreactor was the most promising closed cultivation system. All species could be grown in the carboy photobioreactor. However, P. carterae was the only species which grew in an airlift photobioreactor. Despite several attempts to grow these coccolithophorid species in the tubular photobioreactor (Biocoil), including modification of the airlift and sparger design, no net growth could be achieved. The shear produced by turbulence and bubble effects are the most likely reasons for this failure to grow in the Biocoil. The highest total dry weight, lipid and calcium carbonate productivities achieved by P. carterae in the plate photobioreactors were 0.54, 0.12, and 0.06 g L(-1) day(-1) respectively. Irrespective of the type of photobioreactor, the productivities were P. carterae > E. huxleyi > G. oceanica. Pleurochrysis carterae lipid (20-25% of dry weight) and calcium carbonate (11-12% of dry weight) contents were also the highest of all species tested. Copyright © 2011 Wiley Periodicals, Inc.

  5. Ocean acidification alters the photosynthetic responses of a coccolithophorid to fluctuating ultraviolet and visible radiation.

    Science.gov (United States)

    Jin, Peng; Gao, Kunshan; Villafañe, Virginia E; Campbell, Douglas A; Helbling, E Walter

    2013-08-01

    Mixing of seawater subjects phytoplankton to fluctuations in photosynthetically active radiation (400-700 nm) and ultraviolet radiation (UVR; 280-400 nm). These irradiance fluctuations are now superimposed upon ocean acidification and thinning of the upper mixing layer through stratification, which alters mixing regimes. Therefore, we examined the photosynthetic carbon fixation and photochemical performance of a coccolithophore, Gephyrocapsa oceanica, grown under high, future (1,000 μatm) and low, current (390 μatm) CO₂ levels, under regimes of fluctuating irradiances with or without UVR. Under both CO₂ levels, fluctuating irradiances, as compared with constant irradiance, led to lower nonphotochemical quenching and less UVR-induced inhibition of carbon fixation and photosystem II electron transport. The cells grown under high CO₂ showed a lower photosynthetic carbon fixation rate but lower nonphotochemical quenching and less ultraviolet B (280-315 nm)-induced inhibition. Ultraviolet A (315-400 nm) led to less enhancement of the photosynthetic carbon fixation in the high-CO₂-grown cells under fluctuating irradiance. Our data suggest that ocean acidification and fast mixing or fluctuation of solar radiation will act synergistically to lower carbon fixation by G. oceanica, although ocean acidification may decrease ultraviolet B-related photochemical inhibition.

  6. The exergy of a phase shift: Ecosystem functioning loss in seagrass meadows of the Mediterranean Sea

    Science.gov (United States)

    Montefalcone, Monica; Vassallo, Paolo; Gatti, Giulia; Parravicini, Valeriano; Paoli, Chiara; Morri, Carla; Bianchi, Carlo Nike

    2015-04-01

    Sustained functioning of ecosystems is predicted to depend upon the maintenance of their biodiversity, structure and integrity. The large consensus achieved in this regard, however, faces to the objective difficulty of finding appropriate metrics to measure ecosystem functioning. Here, we aim at evaluating functional consequence of the phase shift occurring in meadows of the Mediterranean seagrass Posidonia oceanica, a priority habitat that is undergoing regression in many coastal areas due to multiple human pressures. Structural degradation of the P. oceanica ecosystem, consequent to increasing coastal exploitation and climate change, may result in the progressive replacement of this seagrass by opportunistic macrophytes, either native or alien. Reviewing published information and our personal records, we measured changes in biological habitat provisioning, species richness and biomass associated to each of the alternative states characterizing the phase shift. Then, ecosystem functioning was assessed by computing the exergy associated to each state, exergy being a state variable that measures the ecosystem capacity to produce work. Phase shift was consistently shown to imply loss in habitat provision, species richness, and biomass; structural and compositional loss was parallelled by a reduction of exergy content, thus providing for the first time an objective and integrative measure of the loss of ecosystem functioning following the degradation of healthy seagrass meadows.

  7. Molecular Mechanisms behind the Physiological Resistance to Intense Transient Warming in an Iconic Marine Plant.

    Science.gov (United States)

    Marín-Guirao, Lazaro; Entrambasaguas, Laura; Dattolo, Emanuela; Ruiz, Juan M; Procaccini, Gabriele

    2017-01-01

    The endemic Mediterranean seagrass Posidonia oceanica is highly threatened by the increased frequency and intensity of heatwaves. Meadows of the species offer a unique opportunity to unravel mechanisms marine plants activate to cope transient warming, since their wide depth distribution impose divergent heat-tolerance. Understanding these mechanisms is imperative for their conservation. Shallow and deep genotypes within the same population were exposed to a simulated heatwave in mesocosms, to analyze their transcriptomic and photo-physiological responses during and after the exposure. Shallow plants, living in a more unstable thermal environment, optimized phenotype variation in response to warming. These plants showed a pre-adaptation of genes in anticipation of stress. Shallow plants also showed a stronger activation of heat-responsive genes and the exclusive activation of genes involved in epigenetic mechanisms and in molecular mechanisms that are behind their higher photosynthetic stability and respiratory acclimation. Deep plants experienced higher heat-induced damage and activated metabolic processes for obtaining extra energy from sugars and amino acids, likely to support the higher protein turnover induced by heat. In this study we identify transcriptomic mechanisms that may facilitate persistence of seagrasses to anomalous warming events and we discovered that P. oceanica plants from above and below the mean depth of the summer thermocline have differential resilience to heat.

  8. Back to the sea twice: identifying candidate plant genes for molecular evolution to marine life

    Directory of Open Access Journals (Sweden)

    Reusch Thorsten BH

    2011-01-01

    Full Text Available Abstract Background Seagrasses are a polyphyletic group of monocotyledonous angiosperms that have adapted to a completely submerged lifestyle in marine waters. Here, we exploit two collections of expressed sequence tags (ESTs of two wide-spread and ecologically important seagrass species, the Mediterranean seagrass Posidonia oceanica (L. Delile and the eelgrass Zostera marina L., which have independently evolved from aquatic ancestors. This replicated, yet independent evolutionary history facilitates the identification of traits that may have evolved in parallel and are possible instrumental candidates for adaptation to a marine habitat. Results In our study, we provide the first quantitative perspective on molecular adaptations in two seagrass species. By constructing orthologous gene clusters shared between two seagrasses (Z. marina and P. oceanica and eight distantly related terrestrial angiosperm species, 51 genes could be identified with detection of positive selection along the seagrass branches of the phylogenetic tree. Characterization of these positively selected genes using KEGG pathways and the Gene Ontology uncovered that these genes are mostly involved in translation, metabolism, and photosynthesis. Conclusions These results provide first insights into which seagrass genes have diverged from their terrestrial counterparts via an initial aquatic stage characteristic of the order and to the derived fully-marine stage characteristic of seagrasses. We discuss how adaptive changes in these processes may have contributed to the evolution towards an aquatic and marine existence.

  9. Density, size structure, shell orientation and epibiontic colonization of the fan mussel Pinna nobilis L. 1758 (Mollusca: Bivalvia in three contrasting habitats in an estuarine area of Sardinia (W Mediterranean

    Directory of Open Access Journals (Sweden)

    Piero Addis

    2009-03-01

    Full Text Available We investigated the spatial distribution, size structure, shell orientation and valve colonization by epibionts of the endangered Mediterranean bivalve Pinna nobilis in three continuous but different habitats in the Gulf of Oristano (Sardinia, western Mediterranean. The sampling stations chosen were: an estuarine area (E of coastal salt-marshes characterized by unvegetated sea-bottoms; and two areas in a seagrass meadow characterized by an extensive Posidonia oceanica meadow (Mw and patched mixed meadows of P. oceanica and Cymodocea nodosa (Me. We found significant differences in mean densities among stations and the highest value was found in the estuarine area. Shell orientation showed that there was uniform circular distribution of specimens in the Mw station and a unimodal distribution in the Me and E stations, where specimens were set at 0°N and 10°NNE, which is a pattern related to sea drift. Shell epibiosis displayed differences between habitats. The highest valve colonization was in the estuary, with filamentous dark algae and Ostrea edulis reaching almost 90 percent of shell coverage. This study provides new information on habitat preferences and data for assessing local populations of P. nobilis that is useful for its conservation and improving the knowledge of its ecology.

  10. Contribution and constraints by deep geophysics to earthquakes origin and distribution in the Italian peninsula; Contributi e vincoli dalla geofisica profonda all'origine e distribuzione dei terremoti nella penisola italiana

    Energy Technology Data Exchange (ETDEWEB)

    Morelli, C.

    1998-07-01

    pozzi. Piu' di 30 mila Km di sismica a rifrazione e riflessione profonda del CNR hanno rilevato un modello strutturale costituito da una crosta adriatica di spessore normale (30-35 Km) rigida e stabile, da una crosta ligure-tirrenica assottigliata (20-25 Km), riscaldata e fratturata, con finestre nel mantello (nel Tirreno sud-orientale). Il contatto tra le due croste e' una sutura fortemente tettonizzata, cui corrisponde in superficie una fascia di massima sismicita' nella penisola, larga 30-60 Km, piu' larga a nord e piu' stretta a sud e separata nell'Italia centrale da una zona con deformazioni piu' diffuse e rotazioni. Questi dati ricavati dalla nuova rete sismica dell'ING hanno anche consentito di dimostrare che il rilascio di energia sismica nell'Italia peninsulare e' solo debolmente collegato con la convergenza Africa-Europa, ma piuttosto viene meglio spiegato dall'attivita' di due archi di subduzione/collisione (Appennino settentrionale e Appennino meridionale-Calabria-Sicilia). Le discontinuita' suborizzontali nell'interno della crosta rilevate dalla sismica sperimentale e dalla sismologia di precisione rendono ragione di altre caratteristiche della ramp-tectonics.

  11. PRODUTOS DO INTEMPERISMO E AVALIAÇÃO DO NÍVEL DE DETERIORAÇÃO EM ROCHAS ORNAMENTAIS DA FORTALEZA DE SANTA CRUZ (NITERÓI, RJ

    Directory of Open Access Journals (Sweden)

    André Luiz Carvalho da Silva

    2012-12-01

    Full Text Available DOI 10.12957/tamoios.2012.5084RESUMO A Fortaleza de Santa Cruz, magnífico exemplo da arquitetura dos tempos da chegada dos europeus ao nosso continente, começou a ser construída por volta de 1555 na entrada da Baía de Guanabara (Niterói, RJ com blocos de gnaisse facoidal local. De modo geral, rochas empregadas em construções em ambientes litorâneos e urbanos são expostas ao sal marinho, bem como, aos poluentes CO2, S e N e, em decorrência disso, os processos relacionados ao intemperismo podem causar danos consideráveis a essas construções. Na Fortaleza de Santa Cruz foram identificados diversos tipos de crostas (negra, de sal, orgânica, “flowstones” e estalactites como produtos do intemperismo. A intensidade dos processos é diferente nos três pavimentos que compõem a Fortaleza, levando a níveis distintos de deterioração dos blocos de rocha, em função da circulação, teor de umidade e de sal no ar em cada pavimento. Palavras-chaves: intemperismo; rochas ornamentais; crosta negra; dissolução.ABSTRACT The Santa Cruz Fort, a magnificent example of architecture at the time of arrival of the Europeans to our continent, began to be constructed at about 1555 at the entrance of the Guanabara Bay (Niterói, RJ with local blocks of augen gnaiss. In general, rocks employed in constructions in coastal and urban environments are exposed to sea derived salts and pollutants such as CO2, S and N and, as consequence of that, weathering related processes can cause considerable damage to these constructions. In the Santa Cruz Fort, various types of crusts (black, salt, organic, flowstones and stalactites have been identified as weathering products. The intensity of such processes is different in the Fort’s three main floors and that leads to distinct deteriorations levels of the blocks of rock in each floor, a function of air circulation, humidity and salt content.Keywords: Weathering; building stones; black crust; dissolution. 

  12. Large landslides in the Pyrenees: preliminary tasks carried out for a harmonized cross-border risk analysis

    Science.gov (United States)

    Moya, José; Grandjean, Gilles; Copons, Ramon; Vaunat, Jean; Buxó, Pere; Colas, Bastien; Darrozes, José; Gasc, Muriel; Guinau, Marta; Gutiérrez, Francisco; García, Juan Carlos; Virely, Didier; Crosetto, Michele; Mas, Raül

    2017-04-01

    Large landslides are recognised as one of the main erosional agents in mountain ranges, having a significant influence on landscape evolution. However, few efforts have been carried out to assess their geomorphological impact from a regional perspective. Regional-scale investigations are also necessary for the reliable evaluation of the associated risks (i.e. for land-use planning). Large landslides are common in the Pyrenees but: 1) their geographic distribution on a regional scale is not well known; 2) their geological and geomorphological controlling factors have been only studied preliminarily; and 3) their state of activity and stability conditions are unknown for most of the cases. Regional analyses of large landslides, as those carried out by Crosta et al. (2013) in the Alps, are rare worldwide. Jarman et al. (2014) conducted a very preliminary analysis in a sector of the Pyrenees. The construction of a cartographic inventory constitutes the basics for such type of studies, which are typically hindered by the lack of cross-border landslide data bases and methodologies. The aim of this contribution is to present the preliminary works carried out for constructing a harmonized inventory of large landslides in the Pyrenees, involving for the first time both sides of the cordillera and the main groups working in landslide risk in France, Spain and Andorra. Methods used for landslide hazard and risk analysis have been compiled and compared, showing a significant divergence, even as regards the terminology. A preliminary cross-border inventory sheet on risk of large landslides has been prepared. It includes specific fields for the assessment of landslide activity (by using complimentary methods such as morpho-stratigraphy, morphometric analysis and remote techniques) and indirect potential costs (that typically overcome direct ones), which usually are neglected in the existing data bases. Crosta, G.B., Frattini, P. and Agliardi, F., 2013. Deep seated gravitational

  13. Biogenic sediments from coastal ecosystems to beach-dune systems: implications for the adaptation of mixed and carbonate beaches to future sea level rise

    Science.gov (United States)

    De Falco, Giovanni; Molinaroli, Emanuela; Conforti, Alessandro; Simeone, Simone; Tonielli, Renato

    2017-07-01

    Coastal ecosystems produce and store carbonate particles, which play a significant role in the carbonate dynamics of coastal areas and may contribute to the sediment budget of adjacent beaches. In the nearshore seabed of temperate zones (e.g. Mediterranean Sea and South Australia), marine biogenic carbonates are mainly produced inside seagrass meadows. This study quantifies the contribution of biogenic sediments, mainly produced in Posidonia oceanica seagrass meadows and secondarily in photophilic algal communities, to the sediment budget of a Mediterranean beach-dune system (San Giovanni beach, western Sardinia, western Mediterranean Sea). A set of geophysical, petrographic and sedimentological data was used to estimate the sediment volume and composition of the beach-dune system as a whole. The San Giovanni beach-dune system contains 3 797 000 ± 404 000 t of sediment, 83 % (3 137 000 ± 404 000 t) of which is located in the coastal wedge, 16 % (619 000 ± 88 000 t) in the dune fields and 1 % (41 000 ± 15 000 t) in the subaerial beach. The sediments are composed of mixed modern bioclastic and relict bioclastic and non-bioclastic grains from various sources. The system receives a large input of modern bioclastic grains, mainly composed of rhodophytes, molluscs and bryozoans, which derive from sediment production of present-day carbonate factories, particularly P. oceanica seagrass meadows. Radiocarbon dating of modern bioclastic grains indicated that they were produced during the last 4.37 kyr. This value was used to estimate the long-term deposition rates of modern bioclastic sediments in the various beach compartments. The total deposition rate of modern bioclastic grains is 46 000 ± 5000 t century-1, mainly deposited in the coastal wedge (39 000 ± 4 000 t century-1) and dunes (7000 ± 1000 t century-1), and 46 000 t represents ˜ 1.2 % of the total beach-dune sediment mass. Carbonate production from coastal ecosystems was estimated to be 132 000/307 000 t

  14. Detailed chronology of a giant Pleistocene rock-avalanche sequence in the hyperarid southern Peru revealed by jointly applied 10Be and 3He cosmic ray exposure dating : The Study case of the Cerro Caquilluco landslide complex.

    Science.gov (United States)

    Swann, Zerathe; Laurence, Audin; Carlos, Benavente; Régis, Braucher; Pierre-Henri, Blard; Didier, Bourlès; Julien, Carcaillet; Fabrizio, Delgado; Pascal, Lacroix; Valderrama Patricio, Murillo; Aster Team

    2015-04-01

    Giant landslides are recognized to be remarkably abundant on the Western Andean front of southern Peru and northern Chile, especially in the Arica Bend region (e.g. Crosta et al., 2014a). This area is characterized by strong topographic gradients and subsequent incision of deep canyons, due to the evolution of the Andean range that provide suitable conditions for the development of such instabilities. The climate is hyper-arid (Atacama Desert), although rare but highly impulsive wet events have been evidenced since the Pleistocene. In parallel, this region is submitted to strong (Mw 8-9) and recurrent (~100 yrs) subduction earthquakes. Previous studies suggest that large landslides represent the main agent of erosion of the Western Cordillera, providing soft material for subsequent fluvial remobilization. However the lack of time constrains on the numerous fossil landslides identified away from major canyons still hamper to assess a real mass balance of sliding material versus the known fluvial erosion and tectonic uplift rates. Finally the role of landslides in the long-term erosion rates of the Andean range on its arid flank remains quantitatively unknown. Recently, two studies gave divergent opinions about the main factor supposed to control the slope failures in that region. Based on cosmogenic nuclides derived erosion rates, McPhillips et al. (2014) argue that the last Holocene climate variation did not have had any effect on the rate of landsliding, suggesting that here landslides are mainly triggered by earthquake. On the other hand, Margirier et al. (2014) have showed a temporal correlation between a failure episode of the giant Chuquibamba landslide and the Ouki wet climatic event identified on the Altiplano ~100 ka ago. In this study we focus on dating the Cerro Caquilluco rock avalanche complex described by Crosta et al. (2014). With a total volume of about 15 km3, a length of 43 km and an internal structure characterized by various depositional lobes

  15. Controls on Deep Seated Gravitational Slope Deformations in the European Alps

    Science.gov (United States)

    Crosta, Giovanni B.; Frattini, Paolo; Agliardi, Federico

    2013-04-01

    DSGSDs are very large, slow mass movements affecting entire high-relief valley slopes. The first orogen-scale inventory of such phenomena at has been recently presented for the European Alps (Crosta et al 2008, Agliardi et al 2012), and then further implemented. The inventory includes 1034 Deep Seated Gravitational Slope Deformations, widespread over the entire orogen and clustered along major valleys and in some specific sectors of the Alps. In this contribution we systematically explore lithological, structural and topographic controls on DSGSD distribution with the help of multivariate statistical techniques (Principal Component Analysis, Discriminant Analysis). Analysis units for statistical analysis were obtained by creating three square vector grids with 2.5 km, 5 km and 10 km grid cell size, respectively, covering the entire area (about 110,000 km2). For each grid cell, we calculated the density of DSGSD, and we assigned a value for each of the controlling variable considered in the analysis. From the NASA SRTM (Shuttle Radar Topography Mission) DEM we derived land surface parameters, such as relief, slope gradients, slope aspect, mean vertical distance from base level and ruggedness. The SRTM DEM was also used to extract the drainage density, with a threshold of 1 km2 and 10 km2. We also computer the stream power of the 1km2 river network Lithology was obtained by assembling different geological maps (1:200.000 map of Salzburg, 1:250.000 map of France, 1:500.000 maps of Switzerland and Austria, 1:1.000.000 map of Italy) and by reclassifying the geological units into 8 lithological classes (carbonate rocks, metapelites, sandstones and marls, paragneiss, ortogneiss, flysch-type rocks, granitoid/metabasite, Quaternary units, and volcanic rocks). To study the role of seismicity, we calculated the number of earthquakes (CPTI11 and USGS-NEIC database) within a distance dmax from the square cell, calculated adopting Keefer's (1984) equation, and the sum of Arias

  16. A TERCEIRA CRÍTICA KANTIANA E SUA INFLUÊNCIA NO MODERNO CONCEITO DE GEOGRAFIA FÍSICA.

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    Antônio Carlos Vitte

    2006-12-01

    Full Text Available O objetivo deste artigo é demonstrar que a gênese da geografia física moderna está associada ao desenvolvimento da filosofia kantiana, particularmente a partir da Terceira Crítica, também chamada de a Crítica do Juízo. É a partir da relação entre estética e teleologia da natureza que Imannuell Kant (1724-1804 desenvolverá o juízo reflexionante teleológico, onde a forma permitirá à razão organizar a natureza, com forte impacto na Filosofia da Natureza de Schelling e no método morfológico de Goethe. Reflexões que tanto influenciarão Alexander von Humboldt e a sua concepção de espacialidade dos fenômenos na crosta terrestre, bem como a de georelevo, ou seja, a morfologia da Terra como o produto de conexões espaço-temporais entre os elementos da natureza.

  17. Anatomia foliar de quatro espécies do gênero Cattleya Lindl. (Orchidaceae do Planalto Central Brasileiro Foliar anatomy of four species of genus Cattleya Lindl. (Orchidaceae of the Brazilian Central Planalt

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    Rosane Zanenga-Godoy

    2003-03-01

    Full Text Available As espécies analisadas (Cattleya araguaiensis Pabst, C. bicolor Lindl., C. nobilior Rchb. e C. walkeriana Gardn. apresentam epiderme uniestratificada em ambas as faces da lâmina foliar, ocorrendo estômatos na face abaxial; deposição de cera epicuticular em crostas, escamas, flocos e plaquetas; em C. araguaiensis ocorrem estegmatas incrustados nas células epidérmicas; em todas as espécies ocorre hipoderme com células de paredes espessadas; mesofilo bifacial, compacto; células paliçádicas atípicas, com barras de espessamento; feixes vasculares colaterais dispostos alternadamente, acompanhados por bainha de fibras; cordões fibrosos acompanhados por estegmatas ocorrem longitudinalmente na lâmina foliar; presença de ráfides. Os aspectos descritos revelam acentuada xeromorfia, em função de economia de água.The analyzed species (Cattleya araguaiensis Pabst, C. bicolor Lindl., C. nobilior Rchb. e C. walkeriana Gardn. present unistratified epidermis at both surfaces with stomata at abaxial surface; deposition of epicuticular wax in crusts, scales, granules and plates; C. araguaiensis presents stegmata at epidermal cells; others characteristics present at all species are: hypodermis cells with thick walls; bifacial and compact mesophyll; atipic cells ofpalisade parenchyma with thichness bars; collateral vascular bundles alternate accompanied by sheath fibers; cordon fibers accompanied by stegmata in the foliar blade; raphids. The described aspects reveal accentuate xeromorphy for water economy.

  18. Dermatite alérgica sazonal em ovinos

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    Barros Claudio Severo Lombardo de

    2005-01-01

    Full Text Available Descreve-se um surto de dermatite alérgica sazonal em ovinos nos municípios de São Vicente do Sul e Jaguari, Rio Grande do Sul. Os ovinos afetados não tinham raça definida e pertenciam a diversas categorias. As lesões eram vistas principalmente na cabeça (orelhas e ao redor dos olhos, focinho e lábios, úbere, porção distal dos membros e abdômen ventral. Dois padrões de lesão foram encontrados; num padrão agudo havia acentuado eritema associado à grande quantidade de pápulas, pústulas, colaretes epidérmicos e crostas; no padrão crônico, áreas liquenificadas, ulceradas, exsudativas, crostosas, alopécicas e, por vezes, sangrantes, eram vistas nos mesmos locais. Microscopicamente, os ovinos mais recentemente afetados demonstravam dermatite perivascular superficial eosinofílica, já os animais com lesões mais antigas apresentavam dermatite perivascular superficial linfo-histioplasmocitária.

  19. Pseudoxantoma elástico perfurante periumbilical e periareolar Periumbilical and periareolar perforating pseudoxanthoma elasticum

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    Aline Lopes Bressan

    2010-10-01

    Full Text Available O pseudoxantoma elástico perfurante periumbilical (PEPP, ou elastose cálcica perfurante, é distúrbio raro e sua patogênese está associada a alteração da fibra elástica, tendo o trauma provável participação. Apresenta-se caso de paciente de 70 anos com quadro de máculas enegrecidas e pápulas encimadas por crostas na região periareolar e periumbilical há mais de dez anos. O exame histopatológico revelou fibras elásticas alteradas, repletas de cálcio, e formação de pertuito na derme com fibras elásticas degradadas no seu interior. O caso descrito corresponde ao PEPP, que nesta paciente também acomete área periareolar bilateralmente.The periumbilical perforating pseudoxanthoma elasticum or perforating calcific elastosis is a rare disorder and its pathogenesis is associated with the alteration of elastic fibers, which may probably result from trauma. We present the case of a 70-year-old woman with long-time blackish maculas and keratotic surface papules on the periareolar and periumbilical regions. The histopathological examination revealed altered elastic fibers, replete with calcium and formation of a path in the dermis with elastic fibers degraded in their interior, confirming the clinical diagnosis.

  20. Pênfigo foliáceo em um eqüino Pemphigus foliaceus in a horse

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    Gabriel Augusto Monteiro

    2007-04-01

    Full Text Available Pênfigo foliáceo é uma rara afecção cutânea auto-imune que acomete várias espécies. Relata-se o caso de uma égua de quatro anos de idade, sem raça definida, apresentando áreas de alopecia, exsudação e crostas localizadas na face, região peitoral e membros pélvicos, além de prurido. Os exames laboratoriais para pesquisa de ácaros, bactérias e estruturas fúngicas foram negativos. O exame histopatológico revelou uma dermatite pustular intra-epidérmica com acantólise subcorneal, assim como dermatite perivascular superficial, com infiltração de eosinófilos, sendo o quadro compatível com pênfigo foliáceo.Pemphigus foliaceus is an uncommon autoimmune skin disorder affecting various species. A case of a 4-year-old mare of undefined breed, displaying alopecic areas, exsudation and crusty lesions on the face, breast region, and hindlimbs as well as pruritus, is reported. Laboratory exams for mite, bacteria and fungal structures were negative. Histopathological exam revealed an intra-epidermal pustule dermatitis with acantholysis, as well as superficial perisvascular dermatitis with infiltration of eosinophyles, conditions compatible with pemphigus foliaceus.

  1. Esporotricose felina com envolvimento humano na cidade de Pelotas, RS, Brasil

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    Xavier Melissa Orzechowski

    2004-01-01

    Full Text Available A esporotricose é uma micose subcutânea, causada pelo fungo dimórfico Sporothrix schenckii. O presente estudo descreve a ocorrência de esporotricose felina na cidade de Pelotas (Rio Grande do Sul - Brasil, e a transmissão para um atendente da clínica veterinária, ocasionada pela arranhadura do animal doente. O felino apresentava deformação do espelho nasal e lesões cutâneas, enquanto o humano apresentava uma lesão ulcerada na região metacarpiana dorsal esquerda. Foram colhidas crostas e/ou exsudato das lesões do felino e do atendente para diagnóstico micológico, os quais foram cultivados em ágar Sabouraud dextrose acrescido de cloranfenicol e incubados a 25 e 37degreesC, durante 10 dias. O isolamento do S. schenckii confirmou o diagnóstico clínico de esporotricose cutânea disseminada no felino e cutânea localizada no atendente. Esta nota pretende alertar profissionais relacionados à clínica de pequenos animais quanto à existência da doença e o alto risco de transmissão pela mordedura e/ou arranhadura de animais infectados.

  2. Diagnóstico laboratorial de varíola: II. resultados do segundo ano de atividades, de maio de 1969 a maio de 1970

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    H. G. Schatzinayr

    1970-12-01

    Full Text Available Os autores relatam os resultados obtidos no diagnóstico laboratorial de varíola, durante o segundo ano de funcionamento de uma unidade montada no Instituto Presidente Castello Branco, da Fundação Instituto Oswaldo Crus, no Rio de Janeiro. O exame de 105 espécimens de crostas e de 76 de líquido vesicular /pustular, forneceu 39 e 34 amostras de vírus da varíola, respectivamente (Tabela 1. A demora em chegar ao laboratório influencia significativamente a taxa de isolamento de vírus (Tabela 2. Foi encontrada estreita relação entre os diagnósticos clínico e laboratorial (Tabela 3, quando possível compará-los. A inoculação em ovos embrionados após 1 a 2 horas do abaixamento da mebrana cório-alantóica, foi considerada como adequada às condições em que são realizados os exames. O laboratório continua a receber regularmente mais especimens para diagnóstico.

  3. Reduced resilience of a globally distributed coccolithophore to ocean acidification: Confirmed up to 2000 generations, supplement to: Jin, Peng; Gao, Kunshan (2016): Reduced resilience of a globally distributed coccolithophore to ocean acidification: Confirmed up to 2000 generations. Marine Pollution Bulletin, 103(1-2), 101-108

    KAUST Repository

    Jin, Peng

    2016-01-01

    Ocean acidification (OA), induced by rapid anthropogenic CO2 rise and its dissolution in seawater, is known to have consequences for marine organisms. However, knowledge on the evolutionary responses of phytoplankton to OA has been poorly studied. Here we examined the coccolithophore Gephyrocapsa oceanica, while growing it for 2000 generations under ambient and elevated CO2 levels. While OA stimulated growth in the earlier selection period (from generations 700 to 1550), it reduced it in the later selection period up to 2000 generations. Similarly, stimulated production of particulate organic carbon and nitrogen reduced with increasing selection period and decreased under OA up to 2000 generations. The specific adaptation of growth to OA disappeared in generations 1700 to 2000 when compared with that at 1000 generations. Both phenotypic plasticity and fitness decreased within selection time, suggesting that the species\\' resilience to OA decreased after 2000 generations under high CO2 selection.

  4. Reduced resilience of a globally distributed coccolithophore to ocean acidification: Confirmed up to 2000 generations

    KAUST Repository

    Jin, Peng

    2015-12-30

    © 2015 Elsevier Ltd. Ocean acidification (OA), induced by rapid anthropogenic CO2 rise and its dissolution in seawater, is known to have consequences for marine organisms. However, knowledge on the evolutionary responses of phytoplankton to OA has been poorly studied. Here we examined the coccolithophore Gephyrocapsa oceanica, while growing it for 2000 generations under ambient and elevated CO2 levels. While OA stimulated growth in the earlier selection period (from generations ~700 to ~1550), it reduced it in the later selection period up to 2000 generations. Similarly, stimulated production of particulate organic carbon and nitrogen reduced with increasing selection period and decreased under OA up to 2000 generations. The specific adaptation of growth to OA disappeared in generations 1700 to 2000 when compared with that at 1000 generations. Both phenotypic plasticity and fitness decreased within selection time, suggesting that the species\\' resilience to OA decreased after 2000 generations under high CO2 selection.

  5. Diel activity and variability in habitat use of white sea bream in a temperate marine protected area.

    Science.gov (United States)

    Di Lorenzo, Manfredi; Fernández, Tomás Vega; Badalamenti, Fabio; Guidetti, Paolo; Starr, Richard M; Giacalone, Vincenzo Maximiliano; Di Franco, Antonio; D'Anna, Giovanni

    2016-05-01

    Fish populations are often comprised of individuals that use habitats and associated resources in different ways. We placed sonic transmitters in, and tracked movements of, white sea bream (Diplodus sargus sargus) in the no-take zone of a Mediterranean marine protected area: the Torre Guaceto marine protected area, (Adriatic Sea, Italy). Tagged fish displayed three types of diel activity patterns in three different habitats: sand, rocky reefs and "matte" of the seagrass Posidonia oceanica. Individuals were more active during the day than at night. Overall, white sea bream displayed a remarkable behavioural plasticity in habitat use. Our results indicate that the observed behavioural plasticity in the marine protected area could be the result of multiple ecological and environmental drivers such as size, sex and increased intra-specific competition. Our findings support the view that habitat diversity helps support high densities of fishes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Permanent genetic resources added to molecular ecology resources database 1 December 2012-31 January 2013.

    Science.gov (United States)

    Arranz, Silvia E; Avarre, Jean-Christophe; Balasundaram, Chellam; Bouza, Carmen; Calcaterra, Nora B; Cezilly, Frank; Chen, Shi-long; Cipriani, Guido; Cruz, V P; D'Esposito, D; Daniel, Carla; Dejean, Alain; Dharaneedharan, Subramanian; Díaz, Juan; Du, Man; Durand, Jean-Dominique; Dziadek, Jarosław; Foresti, F; Peng-cheng, Fu; Gao, Qing-bo; García, Graciela; Gauffre-Autelin, Pauline; Giovino, Antonio; Goswami, Mukunda; Guarino, Carmine; Guerra-Varela, Jorge; Gutiérrez, Verónica; Harris, D J; Heo, Moon-Soo; Khan, Gulzar; Kim, Mija; Lakra, Wazir S; Lauth, Jérémie; Leclercq, Pierre; Lee, Jeonghwa; Lee, Seung-Ho; Lee, Soohyung; Lee, Theresa; Li, Yin-hu; Liu, Hongbo; Liu, Shufang; Malé, Pierre-Jean G; Mandhan, Rishi Pal; Martinez, Paulino; Mayer, Veronika E; Mendel, Jan; Mendes, N J; Mendonça, F F; Minias, Alina; Minias, Piotr; Oh, Kyeong-Suk; Oliveira, C; Orivel, Jérôme; Orsini, L; Pardo, Belén G; Perera, A; Procaccini, G; Rato, C; Ríos, Néstor; Scibetta, Silvia; Sharma, Bhagwati S; Sierens, Tim; Singh, Akhilesh; Terer, Taita; Triest, Ludwig; Urbánková, Soňa; Vera, Manuel; Villanova, Gabriela V; Voglmayr, Hermann; Vyskočilová, Martina; Wang, Hongying; Wang, Jiu-li; Wattier, Rémi A; Xing, Rui; Yadav, Kamalendra; Yin, Guibo; Yuan, Yanjiao; Yun, Jong-Chul; Zhang, Fa-qi; Zhang, Jing-hua; Zhuang, Zhimeng

    2013-05-01

    This article documents the addition of 268 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alburnoides bipunctatus, Chamaerops humilis, Chlidonias hybrida, Cyperus papyrus, Fusarium graminearum, Loxigilla barbadensis, Macrobrachium rosenbergii, Odontesthes bonariensis, Pelteobagrus vachelli, Posidonia oceanica, Potamotrygon motoro, Rhamdia quelen, Sarotherodon melanotheron heudelotii, Sibiraea angustata, Takifugu rubripes, Tarentola mauritanica, Trimmatostroma sp. and Wallago attu. These loci were cross-tested on the following species: Alburnoides fasciatus, Alburnoides kubanicus, Alburnoides maculatus, Alburnoides ohridanus, Alburnoides prespensis, Alburnoides rossicus, Alburnoides strymonicus, Alburnoides thessalicus, Alburnoides tzanevi, Carassius carassius, Fusarium asiaticum, Leucaspius delineatus, Loxigilla noctis dominica, Pelecus cultratus, Phoenix canariensis, Potamotrygon falkneri, Trachycarpus fortune and Vimba vimba. © 2013 Blackwell Publishing Ltd.

  7. Trace elements in Mediterranean seagrasses: Accumulation, tolerance and biomonitoring. A review.

    Science.gov (United States)

    Bonanno, Giuseppe; Orlando-Bonaca, Martina

    2017-12-15

    This study investigated the state of the art on trace elements in Mediterranean seagrasses, and their close environment (seawater and sediment). The analyzed species were Posidonia oceanica, Cymodocea nodosa, Halophila stipulacea, Zostera marina and Zostera noltei. All these species showed high tolerance to pollution and high capacity of accumulation of trace elements. Seagrasses also showed similar patterns of accumulation: the highest concentrations of As, Hg and Pb were found in the roots, whereas those of Cd, Cr, Cu, Mn, Ni and Zn were found in the leaves. Phytotoxic levels in seagrasses are unknown for most trace elements. The accumulation of trace elements in seagrasses is widely recognized as a risk to the whole food web, but the real magnitude of this risk is still uncertain. Seagrasses are known to act as trace element bioindicators, but this potential is still poorly valued for the creation of biomonitoring networks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. ALEX index enables detection of alien macroalgae invasions across habitats within a marine protected area.

    Science.gov (United States)

    Piazzi, L; Gennaro, P; Atzori, F; Cadoni, N; Cinti, M F; Frau, F; Ceccherelli, G

    2018-03-01

    A modified version of the ALien Biotic IndEX (ALEX) has been recently proposed to evaluate biological invasions in macroalgal assemblages. ALEX was applied in a Marine Protected Area where a recreational-fishing port is present testing the following hypotheses: ALEX increases with the distance from the port, it changes between the two directions off the port and it changes among three different habitats: Cystoseira beds, algal turf and dead matte of the seagrass Posidonia oceanica. A total of 78 native macroalgal taxa and 4 introduced species were found, the Chlorophyta Caulerpa cylindracea and the Rhodophyta Apoglossum gregarium, Acrothamnion preissii and Womersleyella setacea. All study sites were in high quality status highlighting that the assemblages investigated were at an early stage of NIS invasion. However, ALEX detected different values among conditions and habitats within the MPA, suggesting a local dynamics of NIS spread and different resistance to invasion of the investigated habitats. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Pervasive plastisphere: First record of plastics in egagropiles (Posidonia spheroids).

    Science.gov (United States)

    Pietrelli, Loris; Di Gennaro, Alessia; Menegoni, Patrizia; Lecce, Francesca; Poeta, Gianluca; Acosta, Alicia T R; Battisti, Corrado; Iannilli, Valentina

    2017-10-01

    The ability of Posidonia oceanica spheroids (egagropiles, EG) to incorporate plastics was investigated along the central Italy coast. Plastics were found in the 52.84% of the egagropiles collected (n = 685). The more represented size of plastics has range within 1-1.5 cm, comparable to the size of natural fibres. Comparing plastics occurring both in EG and in surrounding sand, Polyethylene, Polyester and Nylon were the most abundant polymers in EG, while PSE, PE, PP and PET were the most represented in sand. In particular PE and PP were significantly more represented in sand, while PE, Nylon, Polyester and microfibers (as pills) were more represented in EG. Within plastics found in EG, 26.9% were microfibers as small pills (PET mixing. These microfibers might be produced by discharges from washing machines and currently represents an emerging pollutant with widespread distribution in marine and freshwater ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Nannochloropsis, a rich source of diacylglycerol acyltransferases for engineering of triacylglycerol content in different hosts.

    Science.gov (United States)

    Zienkiewicz, Krzysztof; Zienkiewicz, Agnieszka; Poliner, Eric; Du, Zhi-Yan; Vollheyde, Katharina; Herrfurth, Cornelia; Marmon, Sofia; Farré, Eva M; Feussner, Ivo; Benning, Christoph

    2017-01-01

    Photosynthetic microalgae are considered a viable and sustainable resource for biofuel feedstocks, because they can produce higher biomass per land area than plants and can be grown on non-arable land. Among many microalgae considered for biofuel production, Nannochloropsis oceanica (CCMP1779) is particularly promising, because following nutrient deprivation it produces very high amounts of triacylglycerols (TAG). The committed step in TAG synthesis is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT). Remarkably, a total of 13 putative DGAT-encoding genes have been previously identified in CCMP1779 but most have not yet been studied in detail. Based on their expression profile, six out of 12 type-2 DGAT-encoding genes ( NoDGTT1 - NoDGTT6 ) were chosen for their possible role in TAG biosynthesis and the respective cDNAs were expressed in a TAG synthesis-deficient mutant of yeast. Yeast expressing NoDGTT5 accumulated TAG to the highest level. Over-expression of NoDGTT5 in CCMP1779 grown in N-replete medium resulted in levels of TAG normally observed only after N deprivation. Reduced growth rates accompanied NoDGTT5 over-expression in CCMP1779. Constitutive expression of NoDGTT5 in Arabidopsis thaliana was accompanied by increased TAG content in seeds and leaves. A broad substrate specificity for NoDGTT5 was revealed, with preference for unsaturated acyl groups. Furthermore, NoDGTT5 was able to successfully rescue the Arabidopsis tag1 - 1 mutant by restoring the TAG content in seeds. Taken together, our results identified NoDGTT5 as the most promising gene for the engineering of TAG synthesis in multiple hosts among the 13 DGAT-encoding genes of N. oceanica CCMP1779. Consequently, this study demonstrates the potential of NoDGTT5 as a tool for enhancing the energy density in biomass by increasing TAG content in transgenic crops used for biofuel production.

  11. Impact of temperature and light intensity on triacylglycerol accumulation in marine microalgae

    International Nuclear Information System (INIS)

    Kurpan Nogueira, Daniel P.; Silva, Anita F.; Araújo, Ofélia Q.F.; Chaloub, Ricardo M.

    2015-01-01

    Triacylglycerol (TAG) productivity of Isochrysis galbana, Nannochloropsis oceanica and Phaeodactylum tricornutum was compared to study their suitability for biotechnological applications. Photoautotrophic batch cultures grown at 20 °C and 50 μmol photons m −2  s −1 showed that N. oceanica had the least TAG content and TAG productivity of the three microalgae. Hence, effects of temperature and light intensity on growth rate and accumulation of TAG were subsequently assessed only in I. galbana and P. tricornutum by cultivation at 20 and 30 °C under 50, 300 and 600 μmol photons m −2  s −1 . Although P. tricornutum did not grow at temperatures higher than 20 °C, an increase in both TAG content (from 28.37 to 39.53%) and productivity (from 15.58 to 31.39 mg L −1  d −1 ) was observed at the highest irradiance values. We also found that combined effects of temperature and light intensity enhanced TAG content (from 18.59 to 31.71%) and productivity (from 11.76 to 21.67 mg L −1  d −1 ) in I. galbana. - Highlights: • Productivity of oil and biomass in batch-cultured marine microalgae was compared. • Increase in temperature and irradiance rose oil productivity in Isochrysis galbana. • An increase in light intensity rose oil productivity in Phaeodactylum tricornutum. • Phaeodactylum tricornutum showed the highest productivity in biomass and neutral lipids

  12. Interannual Change Detection of Mediterranean Seagrasses Using RapidEye Image Time Series.

    Science.gov (United States)

    Traganos, Dimosthenis; Reinartz, Peter

    2018-01-01

    Recent research studies have highlighted the decrease in the coverage of Mediterranean seagrasses due to mainly anthropogenic activities. The lack of data on the distribution of these significant aquatic plants complicates the quantification of their decreasing tendency. While Mediterranean seagrasses are declining, satellite remote sensing technology is growing at an unprecedented pace, resulting in a wealth of spaceborne image time series. Here, we exploit recent advances in high spatial resolution sensors and machine learning to study Mediterranean seagrasses. We process a multispectral RapidEye time series between 2011 and 2016 to detect interannual seagrass dynamics in 888 submerged hectares of the Thermaikos Gulf, NW Aegean Sea, Greece (eastern Mediterranean Sea). We assess the extent change of two Mediterranean seagrass species, the dominant Posidonia oceanica and Cymodocea nodosa , following atmospheric and analytical water column correction, as well as machine learning classification, using Random Forests, of the RapidEye time series. Prior corrections are necessary to untangle the initially weak signal of the submerged seagrass habitats from satellite imagery. The central results of this study show that P. oceanica seagrass area has declined by 4.1%, with a trend of -11.2 ha/yr, while C. nodosa seagrass area has increased by 17.7% with a trend of +18 ha/yr throughout the 5-year study period. Trends of change in spatial distribution of seagrasses in the Thermaikos Gulf site are in line with reported trends in the Mediterranean. Our presented methodology could be a time- and cost-effective method toward the quantitative ecological assessment of seagrass dynamics elsewhere in the future. From small meadows to whole coastlines, knowledge of aquatic plant dynamics could resolve decline or growth trends and accurately highlight key units for future restoration, management, and conservation.

  13. Effect of habitat degradation on competition, carrying capacity, and species assemblage stability.

    Science.gov (United States)

    Calizza, Edoardo; Costantini, Maria Letizia; Careddu, Giulio; Rossi, Loreto

    2017-08-01

    Changes in species' trophic niches due to habitat degradation can affect intra- and interspecific competition, with implications for biodiversity persistence. Difficulties of measuring species' interactions in the field limit our comprehension of competition outcomes along disturbance gradients. Thus, information on how habitat degradation can destabilize food webs is scarce, hindering predictions regarding responses of multispecies systems to environmental changes. Seagrass ecosystems are undergoing degradation. We address effects of Posidonia oceanica coverage reduction on the trophic organization of a macroinvertebrate community in the Tyrrhenian Sea (Italy), hypothesizing increased trophic generalism, niche overlap among species and thus competition and decreased community stability due to degraded conditions. Census data, isotopic analysis, and Bayesian mixing models were used to quantify the trophic niches of three abundant invertebrate species, and intra- and interspecific isotopic and resource-use similarity across locations differing in seagrass coverage. This allowed the computation of (1) competition strength, with respect to each other and remaining less abundant species and (2) habitat carrying capacity. To explore effects of the spatial scale on the interactions, we considered both individual locations and the entire study area ("'meadow scale"). We observed that community stability and habitat carrying capacity decreased as P. oceanica coverage declined, whereas niche width, similarity of resource use and interspecific competition strength between species increased. Competition was stronger, and stability lower, at the meadow scale than at the location scale. Indirect effects of competition and the spatial compartmentalization of species interactions increased stability. Results emphasized the importance of trophic niche modifications for understanding effects of habitat loss on biodiversity persistence. Calculation of competition coefficients based

  14. Temperature modulates coccolithophorid sensitivity of growth, photosynthesis and calcification to increasing seawater pCO₂.

    Directory of Open Access Journals (Sweden)

    Scarlett Sett

    Full Text Available Increasing atmospheric CO₂ concentrations are expected to impact pelagic ecosystem functioning in the near future by driving ocean warming and acidification. While numerous studies have investigated impacts of rising temperature and seawater acidification on planktonic organisms separately, little is presently known on their combined effects. To test for possible synergistic effects we exposed two coccolithophore species, Emiliania huxleyi and Gephyrocapsa oceanica, to a CO₂ gradient ranging from ∼0.5-250 µmol kg⁻¹ (i.e. ∼20-6000 µatm pCO₂ at three different temperatures (i.e. 10, 15, 20°C for E. huxleyi and 15, 20, 25°C for G. oceanica. Both species showed CO₂-dependent optimum-curve responses for growth, photosynthesis and calcification rates at all temperatures. Increased temperature generally enhanced growth and production rates and modified sensitivities of metabolic processes to increasing CO₂. CO₂ optimum concentrations for growth, calcification, and organic carbon fixation rates were only marginally influenced from low to intermediate temperatures. However, there was a clear optimum shift towards higher CO₂ concentrations from intermediate to high temperatures in both species. Our results demonstrate that the CO₂ concentration where optimum growth, calcification and carbon fixation rates occur is modulated by temperature. Thus, the response of a coccolithophore strain to ocean acidification at a given temperature can be negative, neutral or positive depending on that strain's temperature optimum. This emphasizes that the cellular responses of coccolithophores to ocean acidification can only be judged accurately when interpreted in the proper eco-physiological context of a given strain or species. Addressing the synergistic effects of changing carbonate chemistry and temperature is an essential step when assessing the success of coccolithophores in the future ocean.

  15. CANDIDÍASE CUTÂNEA EM CEBUS APELLA (MACACO PREGO CUTANEOUS CANDIDIASIS IN A CEBUS APELLA (CAPUCHINS MONKEYS

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    Anelise Oliveira Fonseca

    2008-10-01

    Full Text Available

    Leveduras do gênero Candida têm sido freqüentemente isoladas de animais domésticos e silvestres, entretanto, candidíase não tem sido reportada em primatas. Encaminhou-se à Faculdade de Veterinária, Departamento de Patologia Animal, um macaco-prego (Cebus apella para necropsia, que vinha apresentando emagrecimento profundo e lesões ulcerativas de pele e mucosas. Fragmentos de pele e órgãos foram processados para histologia e corados com H.E. e Groccot. Para micologia, coletaram-se fragmentos de órgãos, exsudato e crostas da pele, sendo realizado exame direto e cultivo a 37oC. Macroscopicamente, o animal apresentava alopecia, caquexia e ulcerações cutâneas de 1-4 cm. Histologicamente, nas ulcerações, a derme continha infiltrado de mononucleares e proliferação fibroblástica. Mediante utilização de Groccot, encontraram-se hifas e/ou pseudo-hifas e blastoconídeos intralesionais. Em cultivos de crostas e exsudato, observaram-se colônias brilhantes, com superfície lisa e coloração branca a creme. A microscopia das colônias revelou células leveduriformes ovaladas ou alongadas, com brotamento unipolar, gram-positivas. No microcultivo em fubá, observaram-se blastoconídeos globosos terminais, com parede espessa e pseudomicélio abundante e ramificado, com formação de tubo germinativo em albumina de ovo, sendo a levedura classificada como Candida albicans. O estudo aborda o risco da infecção por micoses oportunistas como a candidíase em animais silvestres em cativeiro.

     

    PALAVRAS-CHAVES: Candidiasis, Candida albicans, pele, Cebus apella.

    Candida spp has been frequently isolated from domestic and sylvan animals, however, Candidiasis has not been reported in primates. One Cebus apella, with progressive thinning and ulcerative skin lesions and mucous, was

  16. Shrimp and conventional U-Pb age, Sm-Nd isotopic characteristics and tectonic significance of the K-rich Itapuranga suite in Goiás, Central Brazil

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    MÁRCIO M. PIMENTEL

    2003-03-01

    Full Text Available The Itapuranga alkali granite and Uruana quartz syenite are large K-rich EW-elongated intrusions, in the central part of the Neoproterozoic Brasília Belt, central Brazil. They are associated with Pireneus lineaments, which cut the regional NNW-SSE structures of the southern part of the belt. SHRIMP and conventional U-Pb data for the Itapuranga and Uruana intrusions indicate crystallization ages of 624 ± 10 Ma and 618 ± 4 Ma, respectively. Three zircon cores from the Itapuranga granite yielded U-Pb ages between 1.79 and 1.49 Ga. Sm-Nd T DM ages for both intrusions are 1.44 Ga and epsilonNd(T values are -5.1 and -5.7, suggesting the input of material derived from older (Paleo- to Mesoproterozoic sialic crust in the origin of the parental magmas. Magma mixing structures indicate co-existence of mafic and felsic end-members. The felsic end-member of the intrusions is dominantly represented by crust-derived melts, formed in response to the invasion of Paleo/Mesoproterozoic sialic crust by alkali-rich mafic magmas at ca. 620 Ma. These intrusions are roughly contemporaneous with, or perhaps slightly younger than, the peak of regional metamorphism in the southern Brasília Belt. Their emplacement along the Pireneus lineament suggest a syn-tectonic origin for them, most probably in transtensional settings along these faults.O alcali-granito de Itapuranga e o quartzo-sienito de Uruana são corpos alongados na direção E-W na porção central da Faixa Brasília. Eles são associados com o lineamento dos Pireneus, que cortam as estruturas regionais NNW da faixa. Dados U-Pb (SHRIMP e convencional para as intrusões de Itapuranga e Uruana indicaram idades de 624 ± 10 Ma e 618 ± 4 Ma, respectivamente. Núcleos de três cristais de zircão do granito Itapuranga têm idades entre 1.79 e 1.49 Ga. Idades modelo Sm-Nd são de 1.44 Ga e valores de épsilonNd(T são -5.1 e -5.7, indicando participação de crosta siálica mais antiga (Paleo- a Mesoproteroz

  17. Influence of graphite and serpentine minerals along landslide failure surfaces

    Science.gov (United States)

    Alberti, Stefano; Battista Crosta, Giovanni; Wang, Gonghui; Dattola, Giuseppe; Bertolo, Davide

    2017-04-01

    Landslides and deep-seated gravitational slope deformation (DSGSD) often are concentrated in sedimentary and metasedimentary rocks (e.g. Ambrosi and Crosta, 2006) and in carbonaceous materials (CM), where weaker slip surfaces can be generated more easily, with a behaviour similar to that of fault zone (e.g. Zulauf et al., 1990; Craw, 2002; Oohashi et al., 2011, Nakamura et al., 2015). Among the carbonaceous minerals, graphite (grouped with other silicate sheet minerals) acts as a "solid lubrificant" and plays a key role on frictional properties of the slip surface (Yamasaki et al., 2015). These minerals have one key characteristic in common: the presence of weak bonding along (001) planes. Graphite also has one of the weakest bonding in the crystal structure, and it is characterized by a markedly low coefficient of friction (ca 0.1). A similar behaviour is found in serpentine minerals series and chlorite. We performed these tests on different samples derived from Mont de La Saxe landslide and Chervaz landslide. The first one is located in the upper Aosta Valley, the second in the central part of the Aosta Valley. Both these landslides are characterized by metasedimentary sequences. The undisturbed samples derived by core recovery surveys. We performed a petrographic characterization by XRD (X-Ray Diffraction), XRF (X-Ray Refraction) and SEM (Scansion Electron Microscope) with microprobe in addition to laboratory tests on samples from shear zones. Along these shear zones grains are crushed, their size and shapes are changed and these changes necessarily affect pore-water pressure due to volume change in the shear zone. We performed tests using a dynamic-loading ring-shear apparatus (DPRI-5, Sassa et al., 1997). This apparatus allows to simulate the entire process of failure, from initial static or dynamic loading, through shear failure, pore-pressure changes and possible liquefaction, to large-displacement, steady-state shear movement. It is also possible to

  18. Amianto: a bioética entre o custo e a toxicidade

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    Sileno Corrêa Brum

    2016-10-01

    Full Text Available O amianto ou asbesto é resistente a ataques químicos de ácidos e álcalis e bacteriológicos, incapaz de combustão, de alto isolamento térmico e durabilidade, encontrado na crosta terrestre. Parte da Europa proibiu o seu uso. O Brasil está entre os maiores produtores e consumidores mundiais. Para a relação entre o amianto e a saúde humana há relativo consenso sobre a toxicidade do amianto. A contaminação ocorre pela: exposição às fibras de amianto em residências próximas às fábricas, minerações ou áreas contaminadas; a frequência em ambientes de amianto degradados; amianto livre na natureza ou em pontos de depósito ou descarte de produtos; tubulações de cimento-amianto na rede de distribuição ou em caixas-d’água; e, telhados de cimento-amianto. As principais doenças causadas são a asbestose, o mesotelioma maligno de pleura e o câncer pulmonar. Os valores éticos direcionam para o questionamento sobre a divulgação dos riscos do amianto sem alarme da população, possibilidades de substituição, alternativas de baixo custo e o custo/benefício ambiental, social, econômico e da saúde.

  19. A ASSIMETRIA DE BACIAS HIDROGRÁFICAS E INFLUÊNCIAS LITOESTRUTURAIS NA GEOMORFOLOGIA DO RIO FORMOSO, TO

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    Daniel Santos

    2017-03-01

    Full Text Available O presente trabalho avaliou os aspectos de assimetria da bacia hidrográfica do rio Formoso, TO, a partir da aplicação de parâmetros geomórficos e da análise regional lito-estrutural e geomorfológica. A bacia está estabelecida sobre complexos granulíticos, faixas móveis e extensas coberturas sedimentares. O Geoprocessamento foi utilizado no armazenamento, tratamento e classificação dos dados, e juntamente com as observações de campo, foram feitas análises comparativas e correlativas. O rio Formoso é de oitava ordem, com uma área de 21.593 km² e 20.628 km de canais. Foram aplicados os índices geomórficos Fator de Assimetria da Bacia de Drenagem (FABD e o Fator de Simetria Topográfica Transversal (FSTT. Os índices apontam que bacia hidrográfica possui 76% de área à direita do canal principal (Leste, área que com relevos suavemente ondulados e fortemente ondulados. O caimento do terreno é maior no médio e baixo curso no sentido da Bacia Sedimentar do Bananal, eixo de subsidência regional. Destacam-se os resultados obtidos das análises dos ribeirões Grota da Mata e Água Verde, que possuem forte grau de assimetria associado à ocorrência de crosta lateritica, que recobrem os divisores de água dos patamares interfluviais.

  20. Leishmaniose Canina em Brasília, DF: Uma Revisão da Literatura.

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    Tatyere Constâncio de SOUSA

    2015-09-01

    Full Text Available A leishmaniose é uma doença infecto-parasitária que acomete seres humanos e animais, causada por protozoários do gênero Leishmania. As leishmanioses são importante problema de saúde pública em vários países e estão incluídas entre as seis endemias de maior relevância mundial. São classificadas em tegumentar (LT cutânea e mucocutânea - e visceral (LV. A transmissão ocorre através de picada de insetos flebotomíneos pertencentes aos gêneros Lutzomyia (Novo Mundo e Phlebotomus(Velho Mundo. A Leishmaniose Tegumentar Americana (LTA é uma zoonose distribuída no território brasileiro. Possui evolução crônica e acomete a pele e mucosas, isoladamente ou em associação, de seres humanos, cães, gatos e eqüinos. Nos cães, se caracteriza pela presença de lesões cutâneas ulceradas, recobertas por crostas, localizadas nas orelhas, bolsa escrotal, focinho e membros. A Leishmaniose visceral é uma zoonose que ocorre nas regiões subtropicais e tropicais, causada pela Leishmania (Leishmania chagasi, no Novo e no Velho Mundo. No Brasil, a Leishmaniose Visceral Canina (LVC coexiste com a doença humana e os cães são seu reservatório doméstico. A eutanásia do cão é criticada por isso enfrenta limitações. Apesar das ações de vigilância e controle de LV adotadas no DF, a doença permanece em áreas urbanas e rurais.

  1. Erodibilidade de um cambissolo húmico alumínico léptico, determinada sob chuva natural entre 1989 e 1998 em Lages (SC

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    I. Bertol

    2002-06-01

    Full Text Available O fator de erodibilidade do solo (fator K da Equação Universal de Perda de Solo (EUPS refere-se à susceptibilidade natural do solo à erosão e representa a quantidade de solo perdida por unidade de erosividade da chuva (fator R, sendo o seu conhecimento importante no planejamento conservacionista. Utilizando dados de perda de solo, obtidos sob condições de chuva natural, em tanques coletores de escoamento superficial, e de erosividade (EI30 das chuvas naturais, no período de 1989 a 1998, em Lages (SC, calculou-se, pelo quociente entre essas variáveis e por regressão linear simples entre elas, o fator de erodibilidade do solo para um Cambissolo Húmico alumínico léptico com 0,102 m m-1 de declividade média. Com este objetivo, foram utilizados valores de erosividade (EI30 de 437 eventos de chuva e de perdas de solo, obtidas em parcelas de 3,5 x 22,1 m desprovidas de vegetação e crosta superficial. O preparo do solo, executado no sentido paralelo ao declive duas vezes ao ano, consistiu de uma aração e duas gradagens. Os valores de erodibilidade médios anuais, estimados pelo quociente e por regressão linear simples entre as perdas de solo e as erosividades, foram de 0,0115 e 0,0151 Mg ha h ha-1 MJ-1 mm-1, respectivamente. Pelos respectivos modos de obtenção, os valores de erodibilidade médios estacionais estimados foram de 0,0105 e 0,0121 Mg ha h ha-1 MJ-1 mm-1, para a primavera-verão, e de 0,0132 e 0,0220 Mg ha h ha-1 MJ-1 mm-1, para o outono-inverno.

  2. Avaliação do uso do extrato bruto de Jatropha gossypiifolia L. na cicatrização de feridas cutâneas em ratos Evaluation of the use of raw extract of Jatropha gossypiifolia L. in the healing process of skin wounds in rats

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    Manoel Francisco da Silva Santos

    2006-01-01

    Full Text Available INTRODUÇÃO: O uso de fitoterápicos na cicatrização de feridas cirúrgicas tem sido incrementado nos últimos anos com a busca de princípios ativos que desempenhe efetivo papel neste processo acelerando a recuperação cirúrgica. OBJETIVO: Avaliar os aspectos morfológicos do processo cicatricial de feridas cutâneas abertas de ratos com uso do extrato bruto de Jatropha gossypiifolia L. MÉTODOS: Utilizaram-se 60 ratos da linhagem Wistar. Em cada animal foi realizada uma ferida de 2 cm de diâmetro na região dorsal. Os animais foram distribuídos em dois grupos de 30: grupo Controle - sem tratamento e grupo Jatropha - aplicação de extrato bruto de Jatropha gossypiifolia L. Cada grupo foi subdividido em três subgrupos de 10 animais e avaliados no 7º, 14º e 21º dias do pós-operatório. Realizou-se estudo comparativo entre os dois grupos através da análise macroscópica, a planigrafia digital e análise histológica tendo como parâmetro a proliferação vascular, polimorfonucleares, mononucleares, proliferação fibroblástica, colagenização e reepitelização. RESULTADOS: Na evolução da ferida cutânea tanto no grupo controle como no grupo Jatropha houve exsudação plasmática com formação de crostas superficiais até o 7º dia. A partir dai houve espessamento da crosta e no 14º dia a crosta se destacou, evoluindo para tecido de granulação e epitelização completa no 21º dia com surgimento de novos pelos ao redor da lesão, em todos os animais. Houve ausência significativa da inflamação aguda no 21º dia pós-operatório do grupo Jatropha. Houve diferença significativa na intensidade da inflamação crônica, sendo mais intensa no 7º dia no grupo controle. A proliferação fibroblástica foi mais acentuada no 7º dia pós-operatório do grupo Jatropha, sendo semelhante no 14º e 21º dias pós-operatórios nos demais. A colagenização foi maior no 7º e 14º dias no grupo Jatropha. A re-epitelização foi

  3. Remote Sensing Analysis of Mineralized Alteration in the Ramand Area (Qazvin Province

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    Seyed Abolfazl Ezzati

    2016-07-01

    Full Text Available Introduction The Ramand area, southwest of Buin- Zahra, about 60 kilometers from Qazvin, lies in the igneous belt of the Urmieh-Dokhtar region, the main structural zone of north-central Iran. Rhyodacite and rhyolite lava flows are the principal host rocks of mineralization and alteration of the area, most of which occurs in faulted and brecciated zones alongmaj or northwest-trending fault systems (such as Kour-Cheshmeh, Hassan Abad and their branches. Clay minerals determined from satellite images indicated principally argillic hydrothermal alteration before laboratory mineralogical analysis. According to instrumental analyses, mineralized alteration with greater amounts of argillic halos and lesser amounts of sericitic-propylitic minerals contains quartz veinlets in the vertical and lateral sections. Initially, alteration in the Ramand area was revealed in ETM images by using the SPCA technique of Crosta and Moore, 1990 (Selective Principle Component Analysis. Compared with other techniques, SPCA results have reliable spectral signatures for identifying argillic minerals and Fe-oxides as the main mineralogical association in hydrothermal environments. Subsequently, multispectral images (ASTER were analyzed using band ratios.The results indicated silicification alteration along the faulted regions in the Ramand area. Later, areas of silicification alteration were prospected for precious and base metal mineralization.Sampling results suggested that the altered areas have some potential for epithermal mineralization, according to instrumental analyses and micrographic evidence. Materials and methods 1- Collecting satellite images, geological evidence and related documents 2- Image processing to reveal and identify the mineralized alteration. 3- Sampling of the mineralized zones indicated by the remote sensing. 4- Thin- and polished section microscopic studies. 5- X-ray diffraction analysis (XRD (19 samples, inductively coupled plasma mass

  4. Influência do óleo de Copaifera langsdorffii no reparo de ferida cirúrgica em presença de corpo estranho Influence of Copaifera langsdorffii oil on the repair of a surgical wound in the presence of foreign body

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    Rafael C. Vieira

    2008-08-01

    Full Text Available A Copaifera langsdorffii é uma leguminosa nativa do Brasil, da qual pode ser extraído um óleo, popularmente conhecido como óleo de copaíba. Este óleo é amplamente utilizado para tratamento de feridas cutâneas por ser reconhecido como antiinflamatório e cicatrizante. Apesar disso, poucas comprovações científicas do verdadeiro efeito terapêutico desta planta medicinal foram produzidas. O objetivo desse trabalho foi avaliar o efeito do tratamento tópico com C. langsdorffii no processo de reparo quando um corpo estranho é o indutor da inflamação. Para isso, 60 camundongos da linhagem BALB/c foram submetidos à incisão cirúrgica linear de 1cm no dorso para realizar o implante de uma lamínula de vidro com 12mm de diâmetro no tecido subcutâneo. Quatro tratamentos para a ferida foram estabelecidos: controle (C tratado com solução salina estéril, controle veículo (CV tratado com óleo mineral estéril, tratamento 1 (T1 tratado com diluição (v:v de óleo mineral estéril e óleo de C. langsdorffii, tratamento 2 (T2 tratado com óleo de C. langsdorffii puro. As avaliações foram realizadas em períodos de tempo pré-determinados (1, 3, 5, 7 e 14 dias. Era possível perceber características da fase proliferativa como a reepitelização, a presença de fibroblastos e a neovascularização, porém os grupos tratados com o óleo (T1 e T2 não apresentavam reepitelização aos três dias. Esses grupos aos 5 e 7 dias apresentavam no exame macroscópico maior intensidade de edema, hiperemia e permanência de crostas. Na microscopia, a reepitelização ainda não estava completa e a crosta era serocelular. Nos grupos C e CV, apesar de discreta, era predominante a presença de mononucleares, enquanto nos grupos T1 e T2 o infiltrado inflamatório era misto e com maior intensidade que nos outros grupos. Quatorze dias depois da incisão cirúrgica, os aspectos macroscópicos dos grupos C e CV eram semelhantes e os grupos T1 e T2, apesar

  5. Spatial and temporal variability in coccolithophore abundance and distribution in the NW Iberian coastal upwelling system

    Science.gov (United States)

    Ausín, Blanca; Zúñiga, Diana; Flores, Jose A.; Cavaleiro, Catarina; Froján, María; Villacieros-Robineau, Nicolás; Alonso-Pérez, Fernando; Arbones, Belén; Santos, Celia; de la Granda, Francisco; Castro, Carmen G.; Abrantes, Fátima; Eglinton, Timothy I.; Salgueiro, Emilia

    2018-01-01

    A systematic investigation of the spatial and temporal variability in coccolithophore abundance and distribution through the water column of the NW Iberian coastal upwelling system was performed. From July 2011 to June 2012, monthly sampling at various water depths was conducted at two parallel stations located at 42° N. Total coccosphere abundance was higher at the outer-shelf station, where warmer, nutrient-depleted waters favoured coccolithophore rather than phytoplanktonic diatom blooms, which are known to dominate the inner-shelf location. In seasonal terms, higher coccosphere and coccolith abundances were registered at both stations during upwelling seasons, coinciding with high irradiance levels. This was typically in conjunction with stratified, nutrient-poor conditions (i.e. relaxing upwelling conditions). However, it also occurred during some upwelling events of colder, nutrient-rich subsurface waters onto the continental shelf. Minimum abundances were generally found during downwelling periods, with unexpectedly high coccolith abundance registered in subsurface waters at the inner-shelf station. This finding can only be explained if strong storms during these downwelling periods favoured resuspension processes, thus remobilizing deposited coccoliths from surface sediments, and hence hampering the identification of autochthonous coccolithophore community structure. At both locations, the major coccolithophore assemblages were dominated by Emiliania huxleyi, small Gephyrocapsa group, Gephyrocapsa oceanica, Florisphaera profunda, Syracosphaera spp., Coronosphaera mediterranea, and Calcidiscus leptoporus. Ecological preferences of the different taxa were assessed by exploring the relationships between environmental conditions and temporal and vertical variability in coccosphere abundance. These findings provide relevant information for the use of fossil coccolith assemblages in marine sediment records, in order to infer past environmental conditions, of

  6. Spatial and temporal variability in coccolithophore abundance and distribution in the NW Iberian coastal upwelling system

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    B. Ausín

    2018-01-01

    Full Text Available A systematic investigation of the spatial and temporal variability in coccolithophore abundance and distribution through the water column of the NW Iberian coastal upwelling system was performed. From July 2011 to June 2012, monthly sampling at various water depths was conducted at two parallel stations located at 42° N. Total coccosphere abundance was higher at the outer-shelf station, where warmer, nutrient-depleted waters favoured coccolithophore rather than phytoplanktonic diatom blooms, which are known to dominate the inner-shelf location. In seasonal terms, higher coccosphere and coccolith abundances were registered at both stations during upwelling seasons, coinciding with high irradiance levels. This was typically in conjunction with stratified, nutrient-poor conditions (i.e. relaxing upwelling conditions. However, it also occurred during some upwelling events of colder, nutrient-rich subsurface waters onto the continental shelf. Minimum abundances were generally found during downwelling periods, with unexpectedly high coccolith abundance registered in subsurface waters at the inner-shelf station. This finding can only be explained if strong storms during these downwelling periods favoured resuspension processes, thus remobilizing deposited coccoliths from surface sediments, and hence hampering the identification of autochthonous coccolithophore community structure. At both locations, the major coccolithophore assemblages were dominated by Emiliania huxleyi, small Gephyrocapsa group, Gephyrocapsa oceanica, Florisphaera profunda, Syracosphaera spp., Coronosphaera mediterranea, and Calcidiscus leptoporus. Ecological preferences of the different taxa were assessed by exploring the relationships between environmental conditions and temporal and vertical variability in coccosphere abundance. These findings provide relevant information for the use of fossil coccolith assemblages in marine sediment records, in order to infer past

  7. The Seagrass Effect Turned Upside Down Changes the Prospective of Sea Urchin Survival and Landscape Implications.

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    Simone Farina

    Full Text Available Habitat structure plays an important mediating role in predator-prey interactions. However the effects are strongly dependent on regional predator pools, which can drive predation risk in habitats with very similar structure in opposite directions. In the Mediterranean Sea predation on juvenile sea urchins is commonly known to be regulated by seagrass structure. In this study we test whether the possibility for juvenile Paracentrotus lividus to be predated changes in relation to the fragmentation of the seagrass Posidonia oceanica (four habitat classes: continuous, low-fragmentation, high-fragmentation and rocks, and to the spatial arrangement of such habitat classes at a landscape scale. Sea urchin predation risk was measured in a 20-day field experiment on tethered individuals placed in three square areas 35×35 m2 in size. Variability of both landscape and habitat structural attributes was assessed at the sampling grain 5×5 m2. Predation risk changed among landscapes, as it was lower where more 'rocks', and thus less seagrass, were present. The higher risk was found in the 'continuous' P. oceanica rather than in the low-fragmentation, high-fragmentation and rock habitats (p-values = 0.0149, 0.00008, and 0.0001, respectively. Therefore, the expectation that juvenile P. lividus survival would have been higher in the 'continuous' seagrass habitat, which would have served as shelter from high fish predation pressure, was not met. Predation risk changed across habitats due to different success between attack types: benthic attacks (mostly from whelks were overall much more effective than those due to fish activity, the former type being associated with the 'continuous' seagrass habitat. Fish predation on juvenile sea urchins on rocks and 'high-fragmentation' habitat was less likely than benthic predation in the 'continuous' seagrass, with the low seagrass patch complexity increasing benthic activity. Future research should be aimed at

  8. Gravel beaches nourishment: Modelling the equilibrium beach profile.

    Science.gov (United States)

    López, I; Aragonés, L; Villacampa, Y; Navarro-González, F J

    2018-04-01

    The erosion of the world's coasts and the shortage of sand to mitigate beach erosion are leading to the increasingly common use of gravel for coastal protection and beach nourishment. Therefore, in order to determine the amount of gravel required for such actions, it is important to know perfectly the equilibrium profile of gravel beaches. However, at present, this profile is obtained from formulas obtained mainly after channel tests, and therefore most of them do not adapt to the real profiles formed by gravel beaches in nature. In this article, 31 variables related to sedimentology, waves, morphology and marine vegetation present on the beaches are studied to determine which are the most influential in the profile. From the study carried out, it is obtained that these variables are the steepness and probability of occurrence of the wave perpendicular to the coast, the profile starting slope (between MWL and -2m), the energy reduction coefficient due to Posidonia oceanica as well as the width of the meadow. Using these variables, different numerical models were generated to predict accurately the gravel beach profile, which will lead to a saving in the volume of material used in the order of 1300m 3 /ml of beach with respect to current formulations, and a greater certainty that the beach nourishment carried out will have the desired effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Optimized methods of chromatin immunoprecipitation for profiling histone modifications in industrial microalgae Nannochloropsis spp.

    Science.gov (United States)

    Wei, Li; Xu, Jian

    2018-02-14

    Epigenetic factors such as histone modifications play integral roles in plant development and stress response, yet their implications in algae remain poorly understood. In the industrial oleaginous microalgae Nannochloropsis spp., the lack of an efficient methodology for chromatin immunoprecipitation (ChIP), which determines the specific genomic location of various histone modifications, has hindered probing the epigenetic basis of their photosynthetic carbon conversion and storage as oil. Here, a detailed ChIP protocol was developed for Nannochloropsis oceanica, which represents a reliable approach for the analysis of histone modifications, chromatin state, and transcription factor-binding sites at the epigenetic level. Using ChIP-qPCR, genes related to photosynthetic carbon fixation in this microalga were systematically assessed. Furthermore, a ChIP-Seq protocol was established and optimized, which generated a genome-wide profile of histone modification events, using histone mark H3K9Ac as an example. These results are the first step for appreciation of the chromatin landscape in industrial oleaginous microalgae and for epigenetics-based microalgal feedstock development. © 2018 Phycological Society of America.

  10. Genome editing of model oleaginous microalgae Nannochloropsis spp. by CRISPR/Cas9.

    Science.gov (United States)

    Wang, Qintao; Lu, Yandu; Xin, Yi; Wei, Li; Huang, Shi; Xu, Jian

    2016-12-01

    Microalgae are promising feedstock for biofuels yet mechanistic probing of their cellular network and industrial strain development have been hindered by lack of genome-editing tools. Nannochloropsis spp. are emerging model microalgae for scalable oil production and carbon sequestration. Here we established a CRISPR/Cas9-based precise genome-editing approach for the industrial oleaginous microalga Nannochloropsis oceanica, using nitrate reductase (NR; g7988) as example. A new screening procedure that compares between restriction enzyme-digested nested PCR (nPCR) products derived from enzyme-digested and not-digested genomic DNA of transformant pools was developed to quickly, yet reliably, detect genome-engineered mutants. Deep sequencing of nPCR products directly amplified from pooled genomic DNA revealed over an 1% proportion of 5-bp deletion mutants and a lower frequency of 12-bp deletion mutants, with both types of editing precisely located at the targeted site. The isolated mutants, in which precise deletion of five bases caused a frameshift in NR translation, grow normally under NH 4 Cl but fail to grow under NaNO 3 , and thus represent a valuable chassis strain for transgenic-strain development. This demonstration of CRISPR/Cas9-based genome editing in industrial microalgae opens many doors for microalgae-based biotechnological applications. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  11. Genome-wide identification of transcription factors and transcription-factor binding sites in oleaginous microalgae Nannochloropsis.

    Science.gov (United States)

    Hu, Jianqiang; Wang, Dongmei; Li, Jing; Jing, Gongchao; Ning, Kang; Xu, Jian

    2014-06-26

    Nannochloropsis spp. are a group of oleaginous microalgae that harbor an expanded array of lipid-synthesis related genes, yet how they are transcriptionally regulated remains unknown. Here a phylogenomic approach was employed to identify and functionally annotate the transcriptional factors (TFs) and TF binding-sites (TFBSs) in N. oceanica IMET1. Among 36 microalgae and higher plants genomes, a two-fold reduction in the number of TF families plus a seven-fold decrease of average family-size in Nannochloropsis, Rhodophyta and Chlorophyta were observed. The degree of similarity in TF-family profiles is indicative of the phylogenetic relationship among the species, suggesting co-evolution of TF-family profiles and species. Furthermore, comparative analysis of six Nannochloropsis genomes revealed 68 "most-conserved" TFBS motifs, with 11 of which predicted to be related to lipid accumulation or photosynthesis. Mapping the IMET1 TFs and TFBS motifs to the reference plant TF-"TFBS motif" relationships in TRANSFAC enabled the prediction of 78 TF-"TFBS motif" interaction pairs, which consisted of 34 TFs (with 11 TFs potentially involved in the TAG biosynthesis pathway), 30 TFBS motifs and 2,368 regulatory connections between TFs and target genes. Our results form the basis of further experiments to validate and engineer the regulatory network of Nannochloropsis spp. for enhanced biofuel production.

  12. Highly-efficient enzymatic conversion of crude algal oils into biodiesel.

    Science.gov (United States)

    Wang, Yao; Liu, Jin; Gerken, Henri; Zhang, Chengwu; Hu, Qiang; Li, Yantao

    2014-11-01

    Energy-intensive chemical conversion of crude algal oils into biodiesel is a major barrier for cost-effective algal biofuel production. To overcome this problem, we developed an enzyme-based platform for conversion of crude algal oils into fatty acid methyl esters. Crude algal oils were extracted from the oleaginous microalga Nannochloropsis oceanica IMET1 and converted by an immobilized lipase from Candida antarctica. The effects of different acyl acceptors, t-butanol as a co-solvent, oil to t-butanol ratio, oil to methanol ratio, temperature and reaction time on biodiesel conversion efficiency were studied. The conversion efficiency reached 99.1% when the conversion conditions were optimized, i.e., an oil to t-butanol weight ratio of 1:1, an oil to methanol molar ratio of 1:12, and a reaction time of 4h at 25°C. The enzymatic conversion process developed in this study may hold a promise for low energy consumption, low wastewater-discharge biochemical conversion of algal feedstocks into biofuels. Published by Elsevier Ltd.

  13. Protection enhances community and habitat stability: evidence from a mediterranean marine protected area.

    Science.gov (United States)

    Fraschetti, Simonetta; Guarnieri, Giuseppe; Bevilacqua, Stanislao; Terlizzi, Antonio; Boero, Ferdinando

    2013-01-01

    Rare evidences support that Marine Protected Areas (MPAs) enhance the stability of marine habitats and assemblages. Based on nine years of observation (2001-2009) inside and outside a well managed MPA, we assessed the potential of conservation and management actions to modify patterns of spatial and/or temporal variability of Posidonia oceanica meadows, the lower midlittoral and the shallow infralittoral rock assemblages. Significant differences in both temporal variations and spatial patterns were observed between protected and unprotected locations. A lower temporal variability in the protected vs. unprotected assemblages was found in the shallow infralittoral, demonstrating that, at least at local scale, protection can enhance community stability. Macrobenthos with long-lived and relatively slow-growing invertebrates and structurally complex algal forms were homogeneously distributed in space and went through little fluctuations in time. In contrast, a mosaic of disturbed patches featured unprotected locations, with small-scale shifts from macroalgal stands to barrens, and harsh temporal variations between the two states. Opposite patterns of spatial and temporal variability were found for the midlittoral assemblages. Despite an overall clear pattern of seagrass regression through time, protected meadows showed a significantly higher shoot density than unprotected ones, suggesting a higher resistance to local human activities. Our results support the assumption that the exclusion/management of human activities within MPAs enhance the stability of the structural components of protected marine systems, reverting or arresting threat-induced trajectories of change.

  14. Nannofossil age constraints for the northern KwaZulu-Natal shelf-edge wedge: Implications for continental margin dynamics, South Africa, SW Indian Ocean

    Science.gov (United States)

    Green, A. N.; Ovechkina, M.; Uken, R.

    2008-10-01

    Samples collected from the shelf-edge wedge using surface grab samples and the Jago submersible constrain the KwaZulu-Natal shelf-edge wedge to a late Pliocene age on the basis of the absence of Gephyrocapsa oceanica s.l. and Discoaster brouweri, and the presence of Calcidiscus macintyrei. This correlates with proposed Tertiary sea-level curves for southern Africa and indicates relative sea-level fall during the late Pliocene coupled with hinterland uplift. Exposed failure scarps in the upper portions of submarine canyons yield sediment samples of early Pleistocene ages, indicating the uppermost age of deposition of clinoform topsets exposed in the scarp walls. Partially consolidated, interbedded silty and sandy deposits of similar age outcrop in the thalweg of Leven canyon at a depth of 150 m. These sediments provide an upper age limit of the shelf-edge wedge of early Pleistocene, giving a sedimentation rate of this wedge of 162-309 m/Ma. The distribution of widespread basal-most Pleistocene sediments on the upper slope indicates that these sediments escaped major reworking during sea-level falls associated with Pleistocene glaciations and remain as relict upper slope veneers. The absence of more recent sediments suggests that this area has been a zone of sediment bypass or starvation since the early Pleistocene. Areas where younger sediments mantle deposits of early Pleistocene ages represent areas of offshore bedload parting, re-distributing younger Holocene sediment offshore and downslope.

  15. Spatial patterns of macrophyte composition and landscape along the rocky shores of the Mediterranean-Atlantic transition region (northern Alboran Sea)

    Science.gov (United States)

    Bermejo, Ricardo; Ramírez-Romero, Eduardo; Vergara, Juan J.; Hernández, Ignacio

    2015-03-01

    The Alboran Sea is the westernmost ecoregion of the Mediterranean Sea. It is located in the vicinity of Strait of Gibraltar, the only natural connection of the Mediterranean Sea with global circulation. This ecoregion presents steep and highly variable environmental gradients, thus acting as a natural filter for Mediterranean and Atlantic species. This study aimed to analyse spatial patterns of littoral and upper sublittoral communities and their relationship with oceanographic conditions and coastal geomorphology, and to quantify littoral and upper sublittoral rocky shore communities at landscape scale. The results suggest that oceanographic conditions are the main factor to explain landscape patterns along the studied area, while geomorphological features should be related with local-scale variability. In this sense, three biogeographic subregions, matching with oceanographic patterns, were identified: western, central and eastern. These subregions showed significant differences in the structure and the composition of the littoral and upper sublittoral community, which can be explained by regional oceanographic dynamics. Posidonia oceanica, Cystoseira ericaefolia group and Mytilus spp. were the species that most contributed to landscape dissimilarity between the three subregions identified. The central oceanographic region, where the environmental conditions were more variable, showed the poorer and less differentiated flora, suggesting the existence of a divergent boundary between the Atlantic and the Mediterranean Sea.

  16. Bioaccumulation of PCBs in the sea urchin Paracentrotus lividus: seawater and food exposures to a 14C-radiolabelled congener (PCB no. 153)

    International Nuclear Information System (INIS)

    Danis, B.; Cotret, O.; Teyssie, J.L.; Bustamante, P.; Fowler, S.W.; Warnau, M.

    2005-01-01

    Adult Paracentrotus lividus were exposed to a 14 C-labelled PCB congener (PCB no. 153) using two different exposure modes: (1) the surrounding sea water and (2) the food (viz. the phanerogam Posidonia oceanica and the brown alga Taonia atomaria). Uptake kinetics from water and loss kinetics after single feeding were followed in four body compartments of the sea urchins (body wall, spines, gut and gonads). Results indicate that PCB bioaccumulation in P. lividus varies from one body compartment to another, with the exposure mode and the nature of the food. The echinoids accumulate PCB no. 153 more efficiently when exposed via water than via the food (the transfer efficiency is higher by one order of magnitude). Target body compartments of PCB no. 153 were found to be body wall and spines when individuals were exposed via water, and gut when they were exposed via food. It is concluded that P. lividus is an efficient bioaccumulator of PCB and that it could be considered as an interesting indicator for monitoring PCB contamination in the marine environment. - The sea urchin Paracentrotus lividus is a valuable indicator for PCB contamination

  17. Plate motions, Gondwana Dinosaurs, Noah's Arks, Beached Viking Funeral Ships, Ghost Ships, and Landspans

    Directory of Open Access Journals (Sweden)

    Louis L. Jacobs

    2011-03-01

    Full Text Available Gondwana landmasses have served as large-scale biogeographic Noah's Arks and Beached Viking Funeral Ships, as defined by McKenna. The latitudinal trajectories of selected Gondwana dinosaur localities were traced through time in order to evaluate their movement through climate zones relative to those in which they originally formed. The dispersal of fauna during the breakup of Gondwana may have been facilitated by the presence of offshelf islands forming landspans (sensu Iturralde-Vinent and MacPhee in the Equatorial Atlantic Gateway and elsewhere.As massas de terra do Gondwana serviram como Arcas de Noe biogeograficas de grande escala e Navios Funerarios Vikings encalhados, conforme definido por McKenna. As trajetorias latitudinais de areas selecionadas de dinossauros do Gondwana foram tracadas ao longo do tempo a fim de avaliar seu movimento atraves de zonas climaticas relativas aquelas nas quais elas foram originalmente formadas. A dispersao da fauna durante a quebra do Gondwana pode ter sido facilitada pela presenca de ilhas oceanicas formando extensoes de terra (sensu Iturralde-Vinent e MacPhee na entrada do Atlantico Equatorial e em outros lugares.

  18. Comparative management of offshore posidonia residues: composting vs. energy recovery.

    Science.gov (United States)

    Cocozza, Claudio; Parente, Angelo; Zaccone, Claudio; Mininni, Carlo; Santamaria, Pietro; Miano, Teodoro

    2011-01-01

    Residues of the marine plant posidonia (Posidonia oceanica, PO) beached in tourist zones represent a great environmental, economical, social and hygienic problem in the Mediterranean Basin, in general, and in the Apulia Region in particular, because of the great disturb to the bathers and population, and the high costs that the administrations have to bear for their removal and disposal. In the present paper, Authors determined the heating values of leaves and fibres of PO, the main offshore residues found on beaches, and, meantime, composted those residues with mowing and olive pruning wood. The final composts were characterized for pH, electrical conductivity, elemental composition, dynamic respiration index, phytotoxicity, fluorescence and infrared spectroscopic fingerprints. The aim of the paper was to investigate the composting and energy recovery of PO leaves and fibres in order to suggest alternative solutions to the landfill when offshore residues have to be removed from recreational beaches. The fibrous portion of PO residues showed heating values close to those of other biofuels, thus suggesting a possible utilization as source of energy. At the same time, compost obtained from both PO wastes showed high quality features on condition that the electrical conductivity and Na content are lowered by a correct management of wetting during the composting. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Towards a framework for assessment and management of cumulative human impacts on marine food webs.

    Science.gov (United States)

    Giakoumi, Sylvaine; Halpern, Benjamin S; Michel, Loïc N; Gobert, Sylvie; Sini, Maria; Boudouresque, Charles-François; Gambi, Maria-Cristina; Katsanevakis, Stelios; Lejeune, Pierre; Montefalcone, Monica; Pergent, Gerard; Pergent-Martini, Christine; Sanchez-Jerez, Pablo; Velimirov, Branko; Vizzini, Salvatrice; Abadie, Arnaud; Coll, Marta; Guidetti, Paolo; Micheli, Fiorenza; Possingham, Hugh P

    2015-08-01

    Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the food web components, and assessed the components' vulnerability to those threats. Some threats had high (e.g., coastal infrastructure) or low impacts (e.g., agricultural runoff) on all food web components, whereas others (e.g., introduced carnivores) had very different impacts on each component. Partitioning the ecosystem into its components enabled us to identify threats previously overlooked and to reevaluate the importance of threats commonly perceived as major. By incorporating this understanding of system vulnerability with data on changes in the state of each threat (e.g., decreasing domestic pollution and increasing fishing) into a food web model, managers may be better able to estimate and predict cumulative human impacts on ecosystems and to prioritize conservation actions. © 2015 Society for Conservation Biology.

  20. Reduced calcification of marine plankton in response to increased atmospheric CO2.

    Science.gov (United States)

    Riebesell, U; Zondervan, I; Rost, B; Tortell, P D; Zeebe, R E; Morel, F M

    2000-09-21

    The formation of calcareous skeletons by marine planktonic organisms and their subsequent sinking to depth generates a continuous rain of calcium carbonate to the deep ocean and underlying sediments. This is important in regulating marine carbon cycling and ocean-atmosphere CO2 exchange. The present rise in atmospheric CO2 levels causes significant changes in surface ocean pH and carbonate chemistry. Such changes have been shown to slow down calcification in corals and coralline macroalgae, but the majority of marine calcification occurs in planktonic organisms. Here we report reduced calcite production at increased CO2 concentrations in monospecific cultures of two dominant marine calcifying phytoplankton species, the coccolithophorids Emiliania huxleyi and Gephyrocapsa oceanica. This was accompanied by an increased proportion of malformed coccoliths and incomplete coccospheres. Diminished calcification led to a reduction in the ratio of calcite precipitation to organic matter production. Similar results were obtained in incubations of natural plankton assemblages from the north Pacific ocean when exposed to experimentally elevated CO2 levels. We suggest that the progressive increase in atmospheric CO2 concentrations may therefore slow down the production of calcium carbonate in the surface ocean. As the process of calcification releases CO2 to the atmosphere, the response observed here could potentially act as a negative feedback on atmospheric CO2 levels.

  1. Rapid Aggregation of Biofuel-Producing Algae by the Bacterium Bacillus sp. Strain RP1137

    Science.gov (United States)

    Powell, Ryan J.

    2013-01-01

    Algal biofuels represent one of the most promising means of sustainably replacing liquid fuels. However, significant challenges remain before alga-based fuels become competitive with fossil fuels. One of the largest challenges is the ability to harvest the algae in an economical and low-energy manner. In this article, we describe the isolation of a bacterial strain, Bacillus sp. strain RP1137, which can rapidly aggregate several algae that are candidates for biofuel production, including a Nannochloropsis sp. This bacterium aggregates algae in a pH-dependent and reversible manner and retains its aggregation ability after paraformaldehyde fixation, opening the possibility for reuse of the cells. The optimal ratio of bacteria to algae is described, as is the robustness of aggregation at different salinities and temperatures. Aggregation is dependent on the presence of calcium or magnesium ions. The efficiency of aggregation of Nannochloropsis oceanica IMET1 is between 70 and 95% and is comparable to that obtained by other means of harvest; however, the rate of harvest is fast, with aggregates forming in 30 s. PMID:23892750

  2. Unlocking nature’s treasure-chest: screening for oleaginous algae

    Science.gov (United States)

    Slocombe, Stephen P.; Zhang, QianYi; Ross, Michael; Anderson, Avril; Thomas, Naomi J.; Lapresa, Ángela; Rad-Menéndez, Cecilia; Campbell, Christine N.; Black, Kenneth D.; Stanley, Michele S.; Day, John G.

    2015-01-01

    Micro-algae synthesize high levels of lipids, carbohydrates and proteins photoautotrophically, thus attracting considerable interest for the biotechnological production of fuels, environmental remediation, functional foods and nutraceuticals. Currently, only a few micro-algae species are grown commercially at large-scale, primarily for “health-foods” and pigments. For a range of potential products (fuel to pharma), high lipid productivity strains are required to mitigate the economic costs of mass culture. Here we present a screen concentrating on marine micro-algal strains, which if suitable for scale-up would minimise competition with agriculture for water. Mass-Spectrophotometric analysis (MS) of nitrogen (N) and carbon (C) was subsequently validated by measurement of total fatty acids (TFA) by Gas-Chromatography (GC). This identified a rapid and accurate screening strategy based on elemental analysis. The screen identified Nannochloropsis oceanica CCAP 849/10 and a marine isolate of Chlorella vulgaris CCAP 211/21A as the best lipid producers. Analysis of C, N, protein, carbohydrate and Fatty Acid (FA) composition identified a suite of strains for further biotechnological applications e.g. Dunaliella polymorpha CCAP 19/14, significantly the most productive for carbohydrates, and Cyclotella cryptica CCAP 1070/2, with utility for EPA production and N-assimilation. PMID:26202369

  3. Levels of heavy metals in wetland and marine vascular plants and their biomonitoring potential: A comparative assessment.

    Science.gov (United States)

    Bonanno, Giuseppe; Borg, Joseph A; Di Martino, Vincenzo

    2017-01-15

    The present study investigated the levels of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn in the seagrasses Posidonia oceanica and Cymodocea nodosa, and in the wetland macrophytes Phragmites australis, Arundo donax, Typha domingensis, Apium nodiflorum, and Nasturtium officinale. Results showed that the bioaccumulation capacity from sediments, translocation, total levels in plant tissues, and bioindication of metals in sediments, are generally species-specific. In particular, the patterns of metals in the aquatic plants studied were overall independent of ecology (coasts vs wetlands), biomass, anatomy (rhizomatous vs non rhizomatous plants), and life form (hemicrytophytes vs hydrophytes). However, marine phanerogams and wetland macrophytes shared some characteristics such as high levels of heavy metals in their below-ground organs, similar capacity of element translocation in the rhizosphere, compartmentalization of metals in the different plant organs, and potential as bioindicators of Cu, Mn and Zn levels in the substratum. In particular, the present findings indicate that, despite ecological and morphological similarities, different plant species tend to respond differently to exposure to heavy metals. Furthermore, this seems to result from the species individual ability to accumulate and detoxify the various metals rather than being attributed to differences in their ecological and morpho-anatomical characteristics. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Spatial distribution modelling of the endangered bivalve Pinna nobilis in a Marine Protected Area

    Directory of Open Access Journals (Sweden)

    M. VÁZQUEZ-LUIS

    2014-09-01

    Full Text Available The spatial distribution of Pinna nobilis densities have been analysed through a geostatistical approach in the MPA of Cabrera National Park, Balearic Islands (Spain, Western Mediterranean Sea. Regression kriging was used to model the effect of environmental variables on the density of living individuals of P. nobilis and generate a predictive map of its distribution within the MPA. The environmental variables considered for the model were: depth; slope; habitat type and heterogeneity; wave exposure; and MPA zoning. A total of 378 transects were randomly distributed with a total of 149,000 m2 surveyed at a depth range from 4.2 to 46 m. The recorded P. nobilis densities are among the highest in the Mediterranean Sea. With respect to the prediction model, results indicate that benthic habitats play a key role in the spatial distribution of P. nobilis, with higher densities in seagrass meadows of Posidonia oceanica. The fan mussel population density peaked at 9 m depth, decreasing with depth. Also, decreasing densities are expected with increasing exposure to waves. The predicted map shows some hotspots of density different in size and distributed along the MPA, and provides valuable information for the spatial conservation management of this species.

  5. A massive ingression of the alien species Mytilus edulis L. (Bivalvia: Mollusca into the Mediterranean Sea following the Costa Concordia cruise-ship disaster

    Directory of Open Access Journals (Sweden)

    E. CASOLI

    2016-03-01

    Full Text Available The Costa Concordia cruise-ship disaster occurred just off the coast of Italy on January 13th, 2012, and entailed the largest marine salvage operation in history. The salvage employed vessels from different European harbours, providing an unexpected means for transporting alien species into the Mediterranean. In this work we identified mussel species using fragments length polymorphism of a nuclear locus and report the first evidence of the transport of the blue mussel, Mytilus edulis Linnaeus, 1758 (Bivalvia: Mollusca, into the Mediterranean Sea, as a part of the fouling community of the hull of an accommodation barge arrived from a NE Atlantic location in October 2012. Furthermore, we describe the rapid growth of this species, under the ASV Pioneer, until its almost total extinction during the summer of 2013, which left a covering of mussel shells on the underlying Posidonia oceanica (Linnaeus Delile, 1813. meadow. This high mortality rate indicated that M. edulis had been exposed to high stress conditions, probably due to different salinity, temperature, and oligotrophic conditions from its place of origin, and there was no spawning event or known settlement on the nearest infralittoral natural habitats. This event reminds us of how the Mediterranean Sea is constantly under alien-species pressure, due to human activities.

  6. Actin, actin-related proteins and profilin in diatoms: a comparative genomic analysis.

    Science.gov (United States)

    Aumeier, Charlotte; Polinski, Ellen; Menzel, Diedrik

    2015-10-01

    Diatoms are heterokont unicellular algae with a widespread distribution throughout all aquatic habitats. Research on diatoms has advanced significantly over the last decade due to available genetic transformation methods and publicly available genome databases. Yet up to now, proteins involved in the regulation of the cytoskeleton in diatoms are largely unknown. Consequently, this work focuses on actin and actin-related proteins (ARPs) encoded in the diatom genomes of Thalassiosira pseudonana, Thalassiosira oceanica, Phaeodactylum tricornutum, Fragilariopsis cylindrus and Pseudo-nitzschia multiseries. Our comparative genomic study revealed that most diatoms possess only a single conventional actin and a small set of ARPs. Among these are the highly conserved cytoplasmic Arp1 protein and the nuclear Arp4 as well as Arp6. Diatom genomes contain genes coding for two structurally different homologues of Arp4 that might serve specific functions. All diatom species examined here lack ARP2 and ARP3 proteins, suggesting that diatoms are not capable of forming the Arp2/3 complex, which is essential in most eukaryotes for actin filament branching and plus-end dynamics. Interestingly, none of the sequenced representatives of the Bacillariophyta phylum code for profilin. Profilin is an essential actin-binding protein regulating the monomer actin pool and is involved in filament plus-end dynamics. This is the first report of organisms not containing profilin. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. A review on phytochemical, ethnomedical and pharmacological studies on genus Sophora, Fabaceae

    Directory of Open Access Journals (Sweden)

    Panthati Murali Krishna

    2012-10-01

    Full Text Available Sophora is a genus of the Fabaceae family, contains about 52 species, nineteen varieties, and seven forms that are widely distributed in Asia, Oceanica, and the Pacific islands, in the family Fabaceae of herbaceous (Sophora flavescens Aiton to trees (Sophora japonica L.. More than fifteen species in this genus have a long history of use in traditional Chinese medicines. In the last decades the use of this genus in traditional Chinese drugs has led to rapid increase in the information available on active components and reported to posses various pharmacological/therapeutic properties. The paper reviews the ethnopharmacology, the biological activities and the correlated chemical compounds of genus Sophora, Fabaceae. More than 300 compounds has been isolated, among them major are quinolizidine alkaloids particularly matrine and oxymatrine and flavonoids particularly prenylated and isoprenylated flavonoids. Modern pharmacological studies and clinical studies demonstrated that these chemical constituens possess wide reaching pharmacological actions like anti oxidant, anticancer, anti-asthamatic, anti-neoplastic, antimicrobial, antiviral, antidote, anti pyretic, cardiotonic, antinflammatory, diuretic and in the treatment of skin diseases like eczema, colitis and psoriasis.

  8. A review on phytochemical, ethnomedical and pharmacological studies on genus Sophora, Fabaceae

    Directory of Open Access Journals (Sweden)

    Panthati Murali Krishna

    2012-04-01

    Full Text Available Sophora is a genus of the Fabaceae family, contains about 52 species, nineteen varieties, and seven forms that are widely distributed in Asia, Oceanica, and the Pacific islands, in the family Fabaceae of herbaceous (Sophora flavescens Aiton to trees (Sophora japonica L.. More than fifteen species in this genus have a long history of use in traditional Chinese medicines. In the last decades the use of this genus in traditional Chinese drugs has led to rapid increase in the information available on active components and reported to posses various pharmacological/therapeutic properties. The paper reviews the ethnopharmacology, the biological activities and the correlated chemical compounds of genus Sophora, Fabaceae. More than 300 compounds has been isolated, among them major are quinolizidine alkaloids particularly matrine and oxymatrine and flavonoids particularly prenylated and isoprenylated flavonoids. Modern pharmacological studies and clinical studies demonstrated that these chemical constituens possess wide reaching pharmacological actions like anti oxidant, anticancer, anti-asthamatic, anti-neoplastic, antimicrobial, antiviral, antidote, anti pyretic, cardiotonic, antinflammatory, diuretic and in the treatment of skin diseases like eczema, colitis and psoriasis.

  9. Structure and mechanics of aegagropilae fiber network.

    Science.gov (United States)

    Verhille, Gautier; Moulinet, Sébastien; Vandenberghe, Nicolas; Adda-Bedia, Mokhtar; Le Gal, Patrice

    2017-05-02

    Fiber networks encompass a wide range of natural and manmade materials. The threads or filaments from which they are formed span a wide range of length scales: from nanometers, as in biological tissues and bundles of carbon nanotubes, to millimeters, as in paper and insulation materials. The mechanical and thermal behavior of these complex structures depends on both the individual response of the constituent fibers and the density and degree of entanglement of the network. A question of paramount importance is how to control the formation of a given fiber network to optimize a desired function. The study of fiber clustering of natural flocs could be useful for improving fabrication processes, such as in the paper and textile industries. Here, we use the example of aegagropilae that are the remains of a seagrass ( Posidonia oceanica ) found on Mediterranean beaches. First, we characterize different aspects of their structure and mechanical response, and second, we draw conclusions on their formation process. We show that these natural aggregates are formed in open sea by random aggregation and compaction of fibers held together by friction forces. Although formed in a natural environment, thus under relatively unconstrained conditions, the geometrical and mechanical properties of the resulting fiber aggregates are quite robust. This study opens perspectives for manufacturing complex fiber network materials.

  10. A numerical investigation of the atmosphere-ocean thermal contrast over the coastal upwelling region of Cabo Frio, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Dourado, M. [Departamento de Meteorologia, Universidade Federal de Pelotas, Pelotas RS (Brazil)]. E-mail: marcelo_dourado@ufpel.edu.br; Pereira de Oliveira, A. [Departamento de Ciencias Atmosfericas, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, (Brazil)

    2008-01-15

    in Cabo Frio. [Spanish] En este trabajo se utiliza un modelo atmosferico unidimensional con una cerradura de segundo orden, conectado a un modelo de capa de mezcla oceanica, para investigar las variaciones temporales de intervalo corto de tiempo de las capas limite atmosferica y oceanica en la region de surgencia costera de Cabo Frio, Brasil (23 grados Celsius S, 42 grados Celsius 08' W). Se realizaron simulaciones numericas para evaluar el impacto de los contrastes termicos entre la atmosfera y el oceano sobre la extension vertical y otras propiedades de estas capas limite. Las simulaciones fueron disenadas tomando en consideracion las observaciones hechas durante la incursion de un frente frio que interrumpio el regimen de surgencia en Cabo Frio en julio de 1992. Las simulaciones han demostrado que, transcurridas 10 horas de mezcla mecanica, debido a una corriente atmosferica constante de 10 m s-1, aumento la altura de la capa limite atmosferica en 214 m cuando el contraste termico inicial es positivo e igual a 2 K (la atmosfera es mas caliente que el oceano durante la surgencia). Para un contraste termico inicial negativo de -2 K (la atmosfera es mas fria que el oceano cuando el regimen de surgencia esta alterado), la incipiente conveccion termica incrementa la mezcla mecanica incrementando la capa limite atmosferica en 360 m. La evolucion vertical de la capa limite atmosferica simulada es consistente con las observaciones en Cabo Frio en regimen de surgencia. Cuando la surgencia no esta presente, la altura de la capa limite atmosferica simulada es cerca de la mitad que la observada en Cabo Frio en julio de 1992. Durante el periodo de 10 horas analizando la capa de mezcla oceanica se incrementa en 2 y 5.4 m, respectivamente, para los contrastes termicos iniciales positivo y negativo de 2 K y -2 K. La extension vertical de la capa de mezcla oceanica es controlada por la presencia de la conveccion termica en la capa limite atmosferica asociada a la ausencia de

  11. First report of acariasis by Caparinia tripilis in African hedgehogs, (Atelerix albiventris, in Costa Rica Primeiro relato de acariasis por Caparinia tripilis em ouriços Africanos, (Atelerix albiventris, na Costa Rica

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    Andrés Moreira

    2013-03-01

    Full Text Available The African hedgehog is one of the newly imported exotic pets which have been observed with increasing regularity in veterinary clinics in Costa Rica. Despite their popularity, information about their diseases is scarce. Within skin diseases of hedgehogs, mange caused by Caparinia spp. is a common diagnosis in other countries. Two adult African hedgehogs, one male and one female, were brought to a private clinic in Heredia, Costa Rica, with chronic pruritic dermatitis, scabs, nearly complete loss of spines, lethargy, dehydration, and weight loss. During physical exam, deposits of dry seborrhea were taken and processed for diagnosis. Microscopic examination revealed psoroptid mites identified as Caparinia tripilis. This is the first report of the presence of Caparinia tripilis in Costa Rica and, to the authors' knowledge, the rest of Central America. O ouriço africano é um dos animais de estimação exótico, recém-importado que tem sido observado com maior regularidade nas clínicas veterinárias da Costa Rica. Apesar da sua popularidade, informações sobre suas doenças são escassas. Dentre as doenças de pele de ouriços, a sarna causada por Caparinia spp. é um diagnóstico comum nos outros países. Dois adultos ouriços africanos, um macho e uma fêmea, foram levados para uma clínica particular, em Heredia, Costa Rica, com a dermatite pruriginosa crônica, crostas, perda quase completa de espinhos, letargia, desidratação e perda de peso. Ao exame físico, os depósitos de seborreia seca foram retirados e processados para o diagnóstico. O exame microscópico revelou ácaros (psoroptidae identificados como Caparinia tripilis. Esse é o primeiro relato da presença de Caparinia tripilis na Costa Rica e, para conhecimento dos autores, o resto da América Central.

  12. O ciclo hidrológico como chave analítica interpretativa de um material didático em Geologia The water cycle as an interpretative analytical clue to analyse a didactic textbook of Geology

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    José Roberto Serra Martins

    2011-01-01

    Full Text Available Desenvolveu-se modelo de análise da concepção geocientífica veiculada em livros didáticos de Ensino Superior, baseado no ciclo da água, sua dinâmica, fluxos e interações. O modelo forneceu bons resultados, ao ser aplicado ao livro "Challenge of the Natural Environment", de Knapp, Ross e McCrae, que descrevem diferentes categorias de riscos geológicos. No ensino de geociências é fundamental distinguir entre os objetos de investigação e de estudo. Os estudos geológicos buscam recompor o objeto de estudo da Geologia o processo histórico-geológico a partir das formas fixadas em rochas e materiais sólidos. O objeto de investigação é a parte acessível da Terra: a crosta, com sua ampla variedade de estruturas, composições, tramas e texturas de rochas. Ao se distinguir objeto de estudo e de investigação, avaliam-se objetivamente riscos ocasionados: (a pelo desconhecimento dos fenômenos naturais ou (b quando se desconsideram efeitos de atividades antrópicas sobre a natureza.This article analyses the textbook published 1991 "Challenge of the Natural Environment", written by Brian Knapp, Simon Ross and Duncan McCrae, adopting the water cycle as a dynamic background for the flows and interactions between the Earth spheres. The water cycle helps students to understand the difference between the subject matter and the investigation of Geology, a distinction which is fundamental for the teaching of Earth Sciences. Such approach helps to understand the way Geology has evolved as a science. The object of investigation is the crust, where a great diversity of structures, rock compositions, fabrics and textures exist. The subject matter is the historical-geological process reconstructed from naturally "fixed" forms. The step-by-step approach goes from the simplest to the most comprehensive concepts; it highlights the risks caused by: (a an incomplete knowledge of natural processes or (b absence of concern for effects of human activities

  13. SURTO DE SARNA CORIÓPTICA EM CAPRINOS NA CIDADE DE GRAVATÁ, REGIÃO AGRESTE DO ESTADO DE PERNAMBUCO OUTBREAK OF CHORIOPTIC MANGE IN GOATS IN THE CITY OF GRAVATÁ IN PERNAMBUCO´S AGRESTE REGION

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    Maria Isabel de Souza

    2009-12-01

    Full Text Available

    A sarna corióptica é de rara ocorrência em caprinos, no entanto trata-se de uma enfermidade cutânea importante, resultando em perdas econômicas decorrentes do retardo no desenvolvimento dos animais, da perda de peso e do prejuízo à indústria de couro. Desse modo, o objetivo do presente artigo é relatar a ocorrência de um surto de sarna corióptica em um rebanho caprino criado no município de Gravatá (Lat. 08° 12’ 04’’ S e Long. 35° 33’ 53’’ O, região Agreste do estado de Pernambuco. Os animais apresentavam extensas áreas de alopecia, eritema, crostas e espessamento da pele na região das axilas, peito, ventre e as faces caudal e craniomedial dos membros posteriores, além de intenso prurido. Foi realizado raspado cutâneo e identificado o ácaro Chorioptes bovis spp.

    PALAVRAS-CHAVES: Caprinos, Chorioptes spp, sarna.

    Chorioptic mange is of rare occurrence in goats, although it is an important skin disease resulting in economic loss due to the delay in the development of the animals, weight loss and economic losses to the leather industry. Thus, the aim of the present article was to report the occurrence of an outbreak of chorioptic mange in a goat flock reared in the city of Gravatá, (Lat. 08° 12’ 04’’ S and Long. 35° 33’ 53’’ W in Pernambuco´s Agreste region. The animals showed wide alopecia areas, erythema, crusts and skin thickness in the following areas: armpits, sternum, ventral abdomen, caudal and cranium-medial facets of the hind legs and severe scratching. Chorioptes bovis spp was identified in skin scrapings.

    KEY WORDS: Chorioptes spp, goats, mange.

  14. Efeito cicatrizante e atividade antibacteriana da Calendula officinalis L. cultivada no Brasil Healing effect and antibacterial activity of Calendula officinalis L. cultivated in Brazil

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    L.M.L. Parente

    2009-01-01

    Full Text Available Desde a antiguidade propriedades medicinais são atribuídas às flores da Calendula officinalis L. (Asteraceae destacando-se a atividade cicatrizante. Estudos sobre a atividade geral de plantas medicinais na cicatrização vêm sendo realizados, sem especificar sobre qual das fases da cicatrização a planta atua. Neste trabalho a atividade cicatrizante e antiinflamatória do extrato etanólico das flores da C. officinalis cultivada no Brasil foi avaliada em feridas cutâneas de ratos Wistar, por meio de avaliação macroscópica e histológica. A atividade antimicrobiana do extrato e das frações hexânica e diclorometano também foi avaliada. A atividade antiinflamatória do extrato etanólico da calêndula foi atribuída à diminuição da exsudação serosa, da hiperemia, da deposição de fibrina e da hiperplasia epidermal, além de resultar em crostas mais delgadas e umedecidas. Observaram-se também aumento de colágeno no tecido de granulação e efeito antibacteriano. Assim, o extrato etanólico da calêndula atuou de forma positiva sobre a atividade cicatricial em feridas cutâneas de ratos, bem como apresentou atividade antibacteriana in vitro.Since ancient history medicinal properties are attributed to flowers of Calendula officinalis L. (Asteraceae, mainly concerning its healing activity. Studies about the general activity of medicinal plants in healing wounds have been conducted without specifying in which healing phase the plant acts. In this work, the anti-inflammatory and healing activity of the ethanolic extract of C. officinalis flowers cultured in Brazil was evaluated in cutaneous wounds of Wistar rats through macroscopic and histological evaluation. The antibacterial activity of the extract and dichloromethane and hexane fractions was also evaluated. The anti-inflammatory activity of calendula ethanolic extract led to a reduction in plasmatic exudation, hyperemia, fibrin deposition and epidermal hyperplasia, besides

  15. Análise de deformação por variação do geopotencial: estudo de caso para o terremoto maule (Mw 8,8 com base em dados mensais da missão Grace

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    Henry Montecino Castro

    Full Text Available O Chile é um laboratório natural de estudos de Geodinâmica em vista da amplitude e variedade de eventos tectônicos. Um caso notável de deformação produzida é a decorrente do evento sísmico com magnitude Mw 8,8, denominado de terremoto do Maule. Este teve epicentro localizado a 60 km ao Sul de Constitución, região que já apresentava consideráveis velocidades obtidas por intermédio de medições GNSS. Vários estudos relacionados com o sinal geofísico gerado pelo terremoto foram realizados, principalmente explorados por intermédio deresultados GNSS e InSAR, somente um estudo com base em gravimetria. No entanto, tais estudos evidenciaram dificuldades relativas às séries temporais analisadas. Destaque-se que a maior parte das séries de posicionamento GNSS foram descontinuadas pelo evento e portanto só existem séries ou antes ou depois do evento. Neste estudo apresenta-se uma alternativa independente para a quantificação da deformação vertical da crosta com base nas variações do potencial anômalo fornecidas pelos coeficientes de Stokes mensais da missão GRACE. Diferenças de altura geoidal entre setembro de 2009 até maio de 2011, obtidas com base nos coeficientes de Stokes em relação a uma solução estática foram calculas para 4 estações pertencentes a rede de monitoramento contínuo (LLFN, ANTC, CONZ e VALP. A expansão dos coeficientes de Stokes foi restrita ao grau e ordem 45. O efeito hidrológico foi removido por intermédio da EWT (Equivalent Water Thickness, traduzido como Equivalente à Espessura d'Água após o uso de um filtro Gaussiano suavizado de 600 km. Os resultados obtidos após a filtragem têm uma alta consistência com os obtidos em poucas estações GNSS remanescentes, conforme reportado em outras investigações.

  16. Resistência à erosão em ravinas, em latossolo argiloarenoso

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    Kalinny Patrícia Vaz Lafayette

    2011-12-01

    Full Text Available As ravinas consistem em uma das formas de erosão hídrica com escoamento superficial concentrado em encostas de áreas degradadas e, ainda, sem escoamentos de subsuperfície. Os objetivos deste trabalho foram estudar o comportamento hidráulico do escoamento superficial das ravinas e determinar a erodibilidade (Kr e a tensão crítica de cisalhamento (τc na superfície de ravinas e, também, a erodibilidade (Kr ao longo do perfil de encostas degradadas do litoral do Estado de Pernambuco. O experimento foi realizado em 2005, em um Latossolo Amarelo de textura argilosa pertencente à Formação Barreiras no município do Cabo de Santo Agostinho, PE. As parcelas foram delimitadas por chapas metálicas cravadas no solo no sentido do declive (1,0 m de largura por 3,0 m de comprimento. Os testes consistiram na aplicação de quatro níveis de vazão, determinando-se o volume de descarga líquida e a massa de sedimentos desagregados. As taxas de desagregação de solo foram lineares em relação às tensões de cisalhamento. Na superfície das ravinas, a erodibilidade (Kr foi de 0,0016 kg N-1 s-1 e a tensão crítica de cisalhamento, de τc = 4,37 Pa. O baixo valor de erodibilidade e o alto de tensão crítica de cisalhamento de τc obtidos na superfície das ravinas possivelmente decorreram da formação de uma crosta superficial originada por ciclos de umedecimento e secagem. A erodibilidade (Kr em profundidade variou entre 0,012 e 0,070 kg N-1 s-1, em função do teor de argila. O regime do escoamento superficial nas ravinas foi turbulento supercrítico e, portanto, semelhante ao do escoamento superficial nos sulcos de erosão, como descrito na literatura.

  17. Retrospectiva das dermatofitoses em cães e gatos atendidos no Hospital Veterinário da Universidade Federal de Mato Grosso, nos anos de 2006 a 2008 A retrospective of dermatophytosis in dogs and cats Veterinary Hospital at the Universidade Federal de Mato Grosso, in the years 2006 to 2008

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    Rita de Cássia da Silva Machado Neves

    2011-08-01

    Full Text Available O objetivo deste estudo foi caracterizar a população canina e felina, atendida em um período de 36 meses, no Hospital Veterinário da Universidade Federal de Mato Grosso - HOVET/UFMT, acometidos por dermatofitose. Esta dermatopatia, que atinge os animais domésticos, é uma infecção fúngica que envolve camadas superficiais da pele, pêlo e unhas. Foram atendidos 279 casos de dermatofitose, 96,8% na espécie canina e 3,2% na espécie felina, totalizando 7,1% do total de 3096 casos consultados nestes três anos. O agente etiológico isolado preponderante foi o Microsporum canis. Os cães de raça definida foram os mais acometidos, mormente os American Pit Bull Terrier (21,7%. Tanto os felinos sem ou com definição racial apresentaram dermatofitose, não sendo possível uma análise estatística fidedigna. Observou-se que a maioria dos animais infectados apresentava de 1 a 3 anos de idade. As lesões mais observadas foram: alopecia, crostas e caspas e estavam localizadas nas regiões da cabeça, de tronco, e de membros. Não foi observada distribuição sazonal.The aim of this study was to characterize the canine and feline population with dermatophytosis, taken to the Veterinary Hospital of Universidade Federal do Mato Grosso - HOVET/UFMT, during a period of 36 months. This skin disease that affects domestic animals is a fungal infection involving the superficial layers of the skin, hair and nails. 279 cases of dermatophytosis were treated, 96.8% in dogs and 3.2% in cats, with a total of 7.1% of the number of 3096 cases assisted in these three years. The predominant etiologic agent was Microsporum canis. The pure breddogs were most affected, especially the American Pit Bull Terrier (21.7%. The cats with and without racial definition were dermatophytosis, cannot be a reliable statistical analysis. It was observed that the majority of animals infected were 1-3 years old. The lesions observed were: alopecia, dandruff and crusts and were

  18. Environmental impact of heavy metals. Arsenic (As); Impatto ambientale da metalli pesanti. L' arsenico (As)

    Energy Technology Data Exchange (ETDEWEB)

    Bressa, G. [Padua Univ., Padua (Italy). Dipt. di Farmacologia e Anestesiologia, Lab. di Tossicologia

    2001-06-01

    Arsenic (As) is a semi-metal which, its abundance on earth's crust being classed at the 20 place, is considered rather scarce in nature; it is however found in the atmosphere of some industrial areas, especially near foundries or thermo-electrical plants using coal as fuel. High levels of As are found in water, mostly in areas rich in natural thermal activity, or in leaching of ground or rocks with high As content. While elementary As isn't toxic, even in high doses, oxidised compounds, pentavalent and trivalent salts, as well as reduced salts such as arsine (AsH{sub 3}) and its derivatives (arsines) are highly dangerous. While experimental studies couldn't unfalteringly prove a potential carcinogenic effect of As, some epidemiological researches show that it can cause cancer. In fact, skin tumours seem to develop more frequently in areas where drinking water presents high contents of arsenic. [Italian] L'arsenico (As) e' un semimetallo scarsamente presente in natura, classificandosi al 20mo posto per abbondanza sulla crosta terrestre, tuttavia e' rinvenibile nell'atmosfera di aree industrializzate, specie in presenza di fonderie e/o centrali termoelettriche che utilizzano come combustibile carbone fossile. Sono riscontrabili alti livelli di As nelle acque per lo piu' in aree di naturale attivita' termale, o per lisciviazione del suolo e da rocce ad altro contenuto di tale elemento. Mentre l'As elementare non e' tossico, anche a dosi rilevanti, i composti ossidati ed i sali pentavalenti e trivalenti, nonche' quelli ridotti, quali l'arsina (AsH{sub 3}) e derivati (arsine), sono estremamente pericolosi. Anche se studi sperimentali non hanno dimostrato con sicurezza un potenziale effetto cancerogeno dell'As, alcune indagini epidemiologiche indicano che eso puo' indurre il cancro. Infatti tumori della cute sembrano svilupparsi molto piu' frequentemente in zone ove l'acqua potabile ha

  19. Surtos de dermatite ulcerativa causados por espinhos de Mimosa setosa, M. debilis e M. pudica (Fabaceae em equinos

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    Saulo A. Caldas

    Full Text Available RESUMO: Descrevem-se, na pele de equídeos, lesões de natureza mecânico-traumática causadas por espinhos de Mimosa spp. Dentre as três espécies da planta identificadas como responsáveis pelas lesões, M. setosa estava presente em maior quantidade (80% e M. debilis e M. pudica encontravam-se em menor proporção na pastagem. Ocorreram três surtos de dermatite ulcerativa em períodos chuvosos de abril a maio de 2013, dezembro de 2013 a fevereiro de 2014 e abril a maio deste mesmo ano. Vinte e cinco equinos do Setor de Reprodução Animal da Universidade Federal Rural do Rio de Janeiro apresentaram, na pele, lesões ulcerativas com contornos irregulares, exsudato hemorrágico, recobertas por crostas. As lesões localizavam-se sobretudo nas regiões de quartela, boleto, articulação escapulo-umeral, lábios superior e inferior, focinho, narinas, bochechas e chanfro. Sete animais foram biopsiados e o exame histopatológico revelou ulceração da epiderme e infiltrado inflamatório constituído por macrófagos e neutrófilos, delimitado por tecido de granulação subjacente. Em alguns casos, foram observados microespículos das referidas plantas (tricomas hirsutos em meio à reação inflamatória. O diagnóstico de dermatite cutânea causada pela ação traumática da planta baseou-se na presença de Mimosa spp. na pastagem, nas características e localização das lesões na pele dos equinos, nos achados histopatológicos e na recuperação após a retirada dos animais do pasto.

  20. Characterization of the Jure (Sindhupalchok, Nepal) Landslide by TLS and field investigations

    Science.gov (United States)

    Jaboyedoff, Michel; Leibundgut, Geoffroy; Penna, Ivanna; Dahal, Ranjan Kumar; Sevkota, Sanjaya; Sudmeier, Karen

    2015-04-01

    images since 2000 indicate an increasing rock fall and scarp development activity of the landslide before this catastrophic event and scarp development. In addition, it seems that some ephemeral springs developed below the unstable mass. The rockslide generated a rock avalanche, which is documented by the effect of volume on the travel distance. This Farböshung varies between 22° and 24° depending on the type of substratum, which is a bit above the standard values. The spreading of the rock mass can be also reproduced by simulations. It seems that the rockslide ran up the opposite slope and then receded as proposed by Crosta et al. (2003) for Val Pola. Furthermore the upper layer of soils on the failure area created an area of "mud splash" in the frontal part of the rock avalanche. Mud splash is supported by the mud and dust cover found in the trees on the opposite slope near the landslide dam. The analysis of this rock avalanche confirmed the general observation that can be made for present rockslides in general. It reactivated large scale instabilities. In addition, the location of such rockslide developed in complex structures accompanied by a degradation of the rock mass conditions. In addition, the impact of the lake on slope stability in and around the reservoir can be noticed. References: Crosta G.B., Imposimato S. and Roddeman D. G. (2003): Numerical modelling of large landslides stability and runout. Natural Hazards and Earth System Sciences, 3: 523-538 ICIMOD (2015): Eye on the Sun Koshi Landslide: Monitoring and Infrastructure Planning Key to Minimizing Scale of Disasters. http://www.icimod.org/?q=14356 NRSM (2014): Landslide on River Sun Koshi, Nepal. http://www.nrsc.gov.in/Nepal_Landslide.html Petley D. (2015): Sunkoshi landslide in Nepal - still no reduction in the lake. The landslide Blog.Blogs.agu.org. SANDRP (2015): Massive landslide blocks Sunkoshi River, Downstream Nepal-India under threat. http://sandrp.wordpress.com/2014/08/02/massive-landslide-blocks-sunkoshi-river-downstream-nepal-india-under-threat/

  1. Erodibilidade de um nitossolo háplico alumínico determinada em condições de campo Erodibility of a typic hapludox evaluated under field conditions

    Directory of Open Access Journals (Sweden)

    Ildegardis Bertol

    2007-06-01

    Full Text Available O termo erodibilidade do solo (fator K na Equação Universal de Perda de Solo - EUPS expressa a suscetibilidade natural do solo à erosão hídrica. O fator K representa a taxa de perda de solo por unidade de erosividade da chuva (fator R na EUPS. O conhecimento do fator K, juntamente com os demais fatores do modelo EUPS, é importante no planejamento conservacionista, pois, por meio desse modelo, estimam-se as perdas médias anuais de solo esperadas para determinadas condições. Dados de perda de solo, obtidos em campo em solo sem cultivo e com preparo convencional, sob condições de chuva simulada, no período de novembro de 2001 a março de 2004, no sul do Planalto Catarinense, foram utilizados para calcular o fator K de um Nitossolo Háplico alumínico típico, com declividade média de 0,15 m m-1. O fator K foi calculado pela razão entre as perdas de solo e a erosividade das chuvas e, ainda, estimado por análise de regressão linear simples entre estas duas variáveis. Foram utilizados valores de erosividade das chuvas (EI30 de 11 testes de chuva simulada e suas respectivas perdas de solo, obtidas em parcelas de 3,5 x 11,0 m, desprovidas de vegetação e de crosta superficial, após terem sido mantidas sem cultivo e sob preparo de solo contínuo por dois anos. O preparo do solo, executado no sentido do declive, duas vezes ao ano, consistiu de uma aração e duas gradagens. A crosta superficial e as plantas espontâneas eram mecanicamente eliminadas por meio de escarificação e de capina manual com enxada. O fator erodibilidade do solo determinado para o Nitossolo Háplico alumínico foi de 0,011 Mg ha h ha-1 MJ-1 mm-1 quando calculado por meio da razão entre os valores anuais de perda de solo e do índice de erosividade das chuvas e de 0,012 Mg ha h ha-1 MJ-1 mm-1 quando estimado por meio de regressão linear simples entre estas duas variáveis.The term soil erodibility (factor K in the Universal Soil Loss Equation - USLE expresses

  2. Animal infections by vaccinia-like viruses in the state of Rio de Janeiro: an expanding disease Infecções animais por vírus semelhantes ao vaccínia no estado do Rio de Janeiro: uma doença em expansão

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    Hermann G. Schatzmayr

    2009-07-01

    ípios no estado do Rio de Janeiro, ao longo dos últimos nove anos. Amostras clínicas foram coletadas de animais com vesículas, pústulas e crostas no úbere e tetas, e da região do nariz e da cavidade oral de bezerros. Um teste de neutralização viral por redução de placas foi desenvolvido para investigar a presença de anticorpos contra Orthopoxvirus. Os fluidos de vesículas / pústulas e as crostas foram testadas por PCR, microscopia eletrônica (ME e por inoculação em células VERO para isolamento viral. Anticorpos contra Orthopoxvirus foram detectados na grande maioria dos animais. O teste de PCR demonstrou homologia entre os vírus isolados e amostras de vírus vaccínia usados como controles. Na ME, partículas típicas de Orthopoxvirus foram observadas em vários espécimes analisados. Os vírus isolados em cultivo celular foram confirmados como Orthopoxvirus por PCR e ME. O gene HA da amostra Cantagalo/IOC isolada em nosso laboratório foi seqüenciado e comparado com outras amostras semelhantes ao vaccínia, mostrando uma alta homologia com a amostra original Cantagalo, tendo sido as duas amostras isoladas em 1999 de gado leiteiro. Anticorpos para Orthopoxvirus foram detectados em um roedor silvestre do gênero Akodon sp. coletado na região noroeste do estado, sugerindo uma circulação de poxvírus na natureza. No entanto, os testes de PCR aplicados a tecidos de roedores silvestres foram negativos. Infecções vesiculares / pustulares em humanos que mantinham contato com os animais afetados também foram relatadas. Assim, infecções por amostras semelhantes ao vírus VACV em bovinos e em humanos parecem em expansão no estado, gerando perdas econômicas em animais e quadros de doença incapacitante temporária em pacientes humanos. Dessa forma, a possibilidade da imunização do gado leiteiro no estado deve ser devidamente avaliada.

  3. Hidrogramas e sedimentogramas associados à erosão hídrica em solo cultivado com diferentes sequências culturais, com diferentes condições físicas na superfície

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    Jeane Cruz Portela

    2011-02-01

    Full Text Available Estudos hidrossedimentológicos detalhados são de grande valia para o melhor entendimento e controle do processo de erosão hídrica e, por conseguinte, para se aprofundar a pesquisa no assunto e, assim, praticar a conservação do solo e da água de modo mais eficaz e duradouro. Considerando isso, realizou-se este trabalho com o objetivo de desenvolver hidrogramas (taxas instantâneas de descarga da enxurrada versus tempo e sedimentogramas (concentrações instantâneas de sedimento na enxurrada e taxas instantâneas de perda de solo versus tempo individualizados (cada repetição de tratamento, associados à erosão hídrica ocorrida em solo cultivado com diferentes sequências culturais (gramíneas e leguminosas de inverno e verão, implantadas em semeadura direta, nos modos de cultivo isolado e consorciado, com diferentes condições físicas na superfície (solo não mobilizado, solo recém-escarificado, solo previamente escarificado e solo recém-gradeado, com presença e ausência de crosta e de completa, pouca e nenhuma cobertura por resíduos culturais. O estudo foi desenvolvido em campo, na EEA/UFRGS, em Eldorado do Sul (RS, usando-se chuva simulada e um Argissolo Vermelho distrófico típico com textura franco-argiloarenosa na camada superficial e declividade média de 0,115 m m-1. No início da pesquisa esse solo encontrava-se bastante degradado. As chuvas simuladas (seis no total, sendo uma para cada teste de erosão foram aplicadas com o aparelho simulador de braços rotativos, todas elas na intensidade planejada de 64 mm h-1 (neste trabalho usaram-se as intensidades observadas das chuvas, as quais variaram de 59,1 a 74,6 mm h-1 e com duração variando de 1 a 3 h (devido almejar-se atingir a condição de equilíbrio da enxurrada em todos os testes de erosão. Observou-se que os hidrogramas e sedimentogramas, de modo geral, resultaram coerentes com as condições das quais foram desenvolvidos. Assim, na maior parte das vezes, os

  4. Constraints on the vital effect in coccolithophore and dinoflagellate calcite by oxygen isotopic modification of seawater

    Science.gov (United States)

    Hermoso, Michaël; Horner, Tristan J.; Minoletti, Fabrice; Rickaby, Rosalind E. M.

    2014-09-01

    In this study, we show that there are independent controls of 18O/16O and 13C/12C fractionation in coccolithophore and dinoflagellate calcite due to the contrasting kinetics of each isotope system. We demonstrate that the direction and magnitude of the oxygen isotope fractionation with respect to equilibrium is related to the balance between calcification rate and the replenishment of the internal pool of dissolved inorganic carbon (DIC). As such, in fast growing cells, such as those of Emiliania huxleyi and Gephyrocapsa oceanica (forming the so-called ;heavy group;), calcification of the internal carbon pool occurs faster than complete isotopic re-adjustment of the internal DIC pool with H2O molecules. Hence, coccoliths reflect the heavy oxygen isotope signature of the CO2 overprinting the whole DIC pool. Conversely, in large and slow growing cells, such as Coccolithus pelagicus ssp. braarudii, complete re-equilibration is achieved due to limited influx of CO2 leading to coccoliths that are precipitated in conditions close to isotopic equilibrium (;equilibrium group;). Species exhibiting the most negative oxygen isotope composition, such as Calcidiscus leptoporus (;light group;), precipitate coccolith under increased pH in the coccolith vesicle, as previously documented by the ;carbonate ion effect;. We suggest that, for the carbon isotope system, any observed deviation from isotopic equilibrium is only ;apparent;, as the carbon isotopic composition in coccolith calcite is controlled by a Rayleigh fractionation originating from preferential incorporation of 12C into organic matter. Therefore, species with low PIC/POC ratios as E. huxleyi and G. oceanica are shifted towards positive carbon isotope values as a result of predominant carbon fixation into the organic matter. By contrast, cells with higher PIC/POC as C. braarudii and C. leptoporus maintain, to some extent, the original negative isotopic composition of the CO2. The calcareous dinoflagellate

  5. First record of Caulerpa cylindracea (Caulerpaceae, Chlorophyta in Andalusia (Southern Spain

    Directory of Open Access Journals (Sweden)

    Altamirano, María

    2014-12-01

    Full Text Available Three different species of Caulerpa (Caulerpaceae, Chlorophyta co-occur in the Mediterranean Sea: two of them are found at the central-eastern basin and are typically considered non aggressive components of the Lessepsian flora [(C. chemnitzia(Esper J.V. Lamouroux and C. racemosa var. lamourouxii (Turner Weber-van Bosse f. requienii(Montagne Weber van Bosse]; a third taxon, C. cylindracea Sonder has aggressively expanded its range since its first observation in 1990, and it is nowadays reported from nearly all the Mediterranean countries. We report a population of C. cylindracea from Almería (Andalusia, Southern Iberian Peninsula at −30 m depth as to be the westernmost record of the invasive variety on the Mediterranean European coast. Therefore, we made use of morphological description and molecular phylogenetics to provide a complete identification of this invasive seaweed in Southern Spain. Our findings are discussed in light of the composition of the receptor communities, such as maërl bed, edges of Posidonia oceanica (Linnaeus Delile, and their ecology. Our results confirmed the suggested directionality of the invasive pathway to be westward to the Strait of Gibraltar, mainly supported by sea currents and vectors of anthropogenic origin.En el Mar Mediterráneo se encuentran tres especies diferentes de Caulerpa (Caulerpaceae, Chlorophyta: dos de ellas se localizan en la cuenca centro oriental y se consideran componentes no agresivos de la flora Lessepsiana (C. chemnitzia(Esper J.V. Lamouroux and C. racemosa var. lamourouxii (Turner Weber-van Bosse f. requienii(Montagne Weber van Bosse; un tercer taxon, C. cylindracea Sonder ha expandido de manera agresiva su rango de distribución desde su primera observación en 1990, y actualmente se registra en casi todos los países de la cuenca mediterránea. En este trabajo se informa sobre una población de C. cylindracea en Almería (Andalucía, Sur de España, a −30 m de profundidad, que

  6. Evaluation of the energy potential, biogenesis and essential characteristics of the geothermal submarine systems in Mexico; Evaluacion del potencial, biogenesis y caracteristicas esenciales de los sistemas geotermicos submarinos en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Arriaga, Mario Cesar [Universidad Michoacana de San Nicolas Hidalgo, Morelia, Michoacan (Mexico)

    2004-12-01

    profundidad, hasta los recursos geotermicos profundos, a mas de 3000 metros de profundidad. Las fuentes geotermicas no tradicionales incluyen las partes profundas y los limites de los reservorios hidrotermales tradicionales, los sistemas en roca seca o humeda caliente, los yacimientos geopresurizados del Golfo de Mexico y los sistemas submarinos hidrotermales observados principalmente en la costa norte mexicana del Oceano Pacifico. La energia geotermica submarina surge por la existencia de rupturas profundas en el fondo marino, a lo largo de los centros de dispersion oceanicos entre las placas tectonicas. Estos sistemas tienen una longitud total aproximada de 65,000 Km. en la corteza oceanica. Hay dos tipos basicos de sistemas marinos existentes en el Golfo de California: los recursos profundos, localizados a lo largo de las cordilleras entre las placas de la corteza oceanica a mas de 2000 m bajo el nivel del mar, y los recursos poco profundos cerca de las plataformas continentales, entre 20 y 50 metros de profundidad. El calor submarino poco profundo tambien se relaciona con fallas y fracturas en el fondo del mar cerca de algunas costas. Este subsistema se encuentra tambien en la costa de Punta Banda en Ensenada, Baja California. El potencial preliminar de la energia contenida en tales reservorios se estima, en promedio, en 1120 MWt por cada km3 de roca submarina. Las caracteristicas quimicas especificas de las aguas hidrotermales encontradas en esos sistemas oceanicos indican que las interacciones agua-roca, ocurren bajo condiciones de presion y temperatura altas. La energia geotermica submarina soporta ricas variedades de comunidades biologicas a profundidades donde las plantas no tienen acceso a la luz solar para realizar la fotosintesis. Hay indicios de que las posibles condiciones para la sintesis de sustancias y elementos quimicos necesaria para el origen de la vida primitiva, pudieron ser los sistemas hidrotermales submarinos.

  7. Glomalin accumulated in seagrass sediments reveals past alterations in soil quality due to land-use change

    Science.gov (United States)

    López-Merino, Lourdes; Serrano, Oscar; Adame, María Fernanda; Mateo, Miguel Ángel; Martínez Cortizas, Antonio

    2015-10-01

    Arbuscular mycorrhizal fungi (AMF), symbionts with most terrestrial plants, produce glomalin-related soil protein (GRSP), which plays a major role in soil structure and quality. Both fungi hyphae and protein production in soils are affected by perturbations related to land-use changes, implying that GRSP is a sensitive indicator of soil quality. Unfortunately, GRSP degrades within years to decades in oxic environments, preventing its use as palaeoecological proxy. However, GRSP is transported to marine, near-shore anoxic sediments, where it accumulates and remains non-degraded, enabling the assessment of its potential as a palaeoecological proxy for soil ecosystem's health. Exploiting this fact, we have obtained for the first time a long-term record (c. 1250 years) of GRSP content using a Posidonia oceanica seagrass mat sediment core from the Western Mediterranean (Portlligat Bay, Spain). The trends in GRSP content matched well with land-use changes related to agrarian activities reconstructed by pollen analysis. In periods of cultivation, GRSP accumulation in the mat decreased. Given the role played by GRSP, the results suggest that agrarian intensification may have resulted in perturbations to soil quality. Thus, GRSP in seagrass mat sediments can be used to assess long-term trends in continental soil quality induced by human activities. These findings open new possibilities in long-term ecology research, as other anoxic environments could be potentially valid too. Testing them would open the possibility to identify long-term patterns in soil quality and other environmental stressors that could also affect AMF and GRSP production in soils.

  8. Identification of characteristic fatty acids to quantify triacylglycerols in microalgae

    Directory of Open Access Journals (Sweden)

    Peili eShen

    2016-02-01

    Full Text Available The fatty acid profiles of lipids from microalgae are unique. Polyunsaturated fatty acids are generally enriched in polar lipids, whereas saturated and monounsaturated fatty acids constitute the majority of fatty acids in triacylglycerols (TAG. Each species has characteristic fatty acids, and their content is positively or negatively correlated with TAGs. The marine oleaginous diatom Phaeodactylum tricornutum was used as the paradigm to determine the quantitative relationship between TAG and characteristic fatty acid content. Fatty acid profiles and TAG content of Phaeodactylum tricornutum were determined in a time course. C16:0/C16:1 and eicosapentaenoic acid (EPA, C20:5n3 were identified as characteristic fatty acids in TAGs and polar lipids, respectively. The percentage of those characteristic fatty acids in total fatty acids had a significant linear relationship with TAG content and thus the correlation coefficient presenting r2 were 0.96, 0.94 and 0.97 respectively. The fatty acid-based method for TAG quantification could also be applied to other microalgae such as Nannochloropsis oceanica in which the r2 of C16:0, EPA were 0.94, 0.97 respectively and Chlorella pyrenoidosa, whose r2 value correspondingly between C18:1, C18:3 and TAG content were 0.91, 0.99 as well. This characteristic fatty acid-based method provided a distinct way to quantify TAGs in microalgae, by which TAGs could be measured precisely by immediate transesterification from wet biomass rather than using conventional methods. This procedure simplified the operation and required smaller samples than conventional methods.

  9. Modelling and Optimization of Nannochloropsis and Chlorella Growth for Various Locations and Seasons

    Science.gov (United States)

    Gharagozloo, P. E.

    2014-12-01

    Efficient production of algal biofuels could reduce dependence on foreign oil providing domestic renewable energy. Algae-based biofuels are attractive for their large oil yield potential despite decreased land use and natural-resource requirements compared to terrestrial energy crops. Important factors controlling algal-lipid productivity include temperature, nutrient availability, salinity, pH, and the light-to-biomass conversion rate. Computational approaches allow for inexpensive predictions of algae-growth kinetics for various bioreactor sizes and geometries without multiple, expensive measurement systems. In this work, we parameterize our physics-based computational algae growth model for the marine Nannochloropsis oceanica and freshwater Chlorella species. We then compare modelling results with experiments conducted in identical raceway ponds at six geographical locations in the United States (Hawaii, California, Arizona, Ohio, Georgia, and Florida) and three seasons through the Algae Testbed Public Private Partnership - Unified Field Studies. Results show that the computational model effectively predicts algae growth in systems across varying environments and identifies the causes for reductions in algal productivities. The model is then used to identify improvements to the cultivation system to produce higher biomass yields. This model could be used to study the effects of scale-up including the effects of predation, depth-decay of light (light extinction), and optimized nutrient and CO2 delivery. As more multifactorial data are accumulated for a variety of algal strains, the model could be used to select appropriate algal species for various geographic and climatic locations and seasons. Applying the model facilitates optimization of pond designs based on location and season.

  10. Fine-Scale Cartography of Human Impacts along French Mediterranean Coasts: A Relevant Map for the Management of Marine Ecosystems.

    Directory of Open Access Journals (Sweden)

    Florian Holon

    Full Text Available Ecosystem services provided by oceans and seas support most human needs but are threatened by human activities. Despite existing maps illustrating human impacts on marine ecosystems, information remains either large-scale but rough and insufficient for stakeholders (1 km² grid, lack of data along the coast or fine-scale but fragmentary and heterogeneous in methodology. The objectives of this study are to map and quantify the main pressures exerted on near-coast marine ecosystems, at a large spatial scale though in fine and relevant resolution for managers (one pixel = 20 x 20 m. It focuses on the French Mediterranean coast (1,700 km of coastline including Corsica at a depth of 0 to 80 m. After completing and homogenizing data presently available under GIS on the bathymetry and anthropogenic pressures but also on the seabed nature and ecosystem vulnerability, we provide a fine modeling of the extent and impacts of 10 anthropogenic pressures on marine habitats. The considered pressures are man-made coastline, boat anchoring, aquaculture, urban effluents, industrial effluents, urbanization, agriculture, coastline erosion, coastal population and fishing. A 1:10 000 continuous habitat map is provided considering 11 habitat classes. The marine bottom is mostly covered by three habitats: infralittoral soft bottom, Posidonia oceanica meadows and circalittoral soft bottom. Around two thirds of the bottoms are found within medium and medium high cumulative impact categories. Seagrass meadows are the most impacted habitats. The most important pressures (in area and intensity are urbanization, coastal population, coastal erosion and man-made coastline. We also identified areas in need of a special management interest. This work should contribute to prioritize environmental needs, as well as enhance the development of indicators for the assessment of the ecological status of coastal systems. It could also help better apply and coordinate management measures

  11. Multiple approaches for the detection and characterization of viral and plasmid symbionts from a collection of marine fungi.

    Science.gov (United States)

    Nerva, L; Ciuffo, M; Vallino, M; Margaria, P; Varese, G C; Gnavi, G; Turina, M

    2016-07-02

    The number of reported mycoviruses is increasing exponentially due to the current ability to detect mycoviruses using next-generation sequencing (NGS) approaches, with a large number of viral genomes built in-silico using data from fungal transcriptome projects. We decided to screen a collection of fungi originating from a specific marine environment (associated with the seagrass Posidonia oceanica) for the presence of mycoviruses: our findings reveal a wealth of diversity among these symbionts and this complexity will require further studies to address their specific role in this ecological niche. In specific, we identified twelve new virus species belonging to nine distinct lineages: they are members of megabirnavirus, totivirus, chrysovirus, partitivirus and five still undefined clades. We showed evidence of an endogenized virus ORF, and evidence of accumulation of dsRNA from metaviridae retroviral elements. We applied different techniques for detecting the presence of mycoviruses including (i) dsRNA extraction and cDNA cloning, (ii) small and total RNA sequencing through NGS techniques, (iii) rolling circle amplification (RCA) and total DNA extraction analyses, (iv) virus purifications and electron microscopy. We tried also to critically evaluate the intrinsic value and limitations of each of these techniques. Based on the samples we could compare directly, RNAseq analysis is superior to sRNA for de novo assembly of mycoviruses. To our knowledge this is the first report on the virome of fungi isolated from marine environment. The GenBank/eMBL/DDBJ accession numbers of the sequences reported in this paper are: KT601099-KT601110; KT601114-KT601120; KT592305; KT950836-KT950841. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Growth phase dependent hydrogen isotopic fractionation in alkenone-producing haptophytes

    Science.gov (United States)

    Wolhowe, M. D.; Prahl, F. G.; Probert, I.; Maldonado, M.

    2009-08-01

    Recent works have investigated use of the hydrogen isotopic composition of C37 alkenones (δDK37s, lipid biomarkers of certain haptophyte microalgae, as an independent paleosalinity proxy. We discuss herein the factors impeding the success of such an application and identify the potential alternative use of δDK37s measurements as a proxy for non-thermal, physiological stress impacts on the U37K' paleotemperature index. Batch-culture experiments with the haptophyte Emiliania huxleyi (CCMP 1742) were conducted to determine the magnitude and variability of the isotopic contrasts between individual C37 alkenones. Further experiments were conducted with Emiliania huxleyi (CCMP 1742) andGephyrocapsa oceanica (PZ3-1) to determine whether, and to what extent, δDK37s varies between the physiological extremes of nutrient-replete exponential growth and nutrient-depleted senescence. Emiliania huxleyi was observed to exhibit an isotopic contrast between di- and tri-unsaturated C37 alkenones (αK37:3-K37:2≈0.97) that is nearly identical to that reported recently by others for environmental samples. Furthermore, this contrast appears to be constant with growth stage. The consistency of the offset across different growth stages suggests that a single, well-defined value for αK37:3-K37:2 may exist and that its use in an isotope mass-balance will allow accurate determination of δD values for individual alkenones without having to rely on time- and labor-intensive chemical separations. The isotopic fractionation between growth medium and C37 alkenones was observed to increase dramatically upon the onset of nutrient-depletion-induced senescence, suggesting that δDK37s may serve as an objective tool for recognizing and potentially correcting, at least semi-quantitatively, for the effects of nutrient stress on U37K' temperature records.

  13. Cubesat-Derived Detection of Seagrasses Using Planet Imagery Following Unmixing-Based Denoising: is Small the Next Big?

    Science.gov (United States)

    Traganos, D.; Cerra, D.; Reinartz, P.

    2017-05-01

    Seagrasses are one of the most productive and widespread yet threatened coastal ecosystems on Earth. Despite their importance, they are declining due to various threats, which are mainly anthropogenic. Lack of data on their distribution hinders any effort to rectify this decline through effective detection, mapping and monitoring. Remote sensing can mitigate this data gap by allowing retrospective quantitative assessment of seagrass beds over large and remote areas. In this paper, we evaluate the quantitative application of Planet high resolution imagery for the detection of seagrasses in the Thermaikos Gulf, NW Aegean Sea, Greece. The low Signal-to-noise Ratio (SNR), which characterizes spectral bands at shorter wavelengths, prompts the application of the Unmixing-based denoising (UBD) as a pre-processing step for seagrass detection. A total of 15 spectral-temporal patterns is extracted from a Planet image time series to restore the corrupted blue and green band in the processed Planet image. Subsequently, we implement Lyzenga's empirical water column correction and Support Vector Machines (SVM) to evaluate quantitative benefits of denoising. Denoising aids detection of Posidonia oceanica seagrass species by increasing its producer and user accuracy by 31.7 % and 10.4 %, correspondingly, with a respective increase in its Kappa value from 0.3 to 0.48. In the near future, our objective is to improve accuracies in seagrass detection by applying more sophisticated, analytical water column correction algorithms to Planet imagery, developing time- and cost-effective monitoring of seagrass distribution that will enable in turn the effective management and conservation of these highly valuable and productive ecosystems.

  14. The Civitavecchia Coastal Environment Monitoring System (C-CEMS): a new tool to analyze the conflicts between coastal pressures and sensitivity areas

    Science.gov (United States)

    Bonamano, S.; Piermattei, V.; Madonia, A.; Paladini de Mendoza, F.; Pierattini, A.; Martellucci, R.; Stefanì, C.; Zappalà, G.; Caruso, G.; Marcelli, M.

    2016-01-01

    The understanding of the coastal environment is fundamental for efficiently and effectively facing the pollution phenomena as expected by the Marine Strategy Framework Directive, and for limiting the conflicts between anthropic activities and sensitivity areas, as stated by Maritime Spatial Planning Directive. To address this, the Laboratory of Experimental Oceanology and Marine Ecology developed a multi-platform observing network that has been in operation since 2005 in the coastal marine area of Civitavecchia (Latium, Italy) where multiple uses and high ecological values closely coexist. The Civitavecchia Coastal Environment Monitoring System (C-CEMS), implemented in the current configuration, includes various components allowing one to analyze the coastal conflicts by an ecosystem-based approach. The long-term observations acquired by the fixed stations are integrated with in situ data collected for the analysis of the physical, chemical and biological parameters of the water column, sea bottom and pollution sources detected along the coast. The in situ data, integrated with satellite observations (e.g., temperature, chlorophyll a and TSM), are used to feed and validate the numerical models, which allow the analysis and forecasting of the dynamics of pollutant dispersion under different conditions. To test the potential capabilities of C-CEMS, two case studies are reported here: (1) the analysis of fecal bacteria dispersion for bathing water quality assessment, and (2) the evaluation of the effects of the dredged activities on Posidonia meadows, which make up most of the two sites of community importance located along the Civitavecchia coastal zone. The simulation outputs are overlapped by the thematic maps showing bathing areas and Posidonia oceanica distribution, thus giving a first practical tool that could improve the resolution of the conflicts between coastal uses (in terms of stress produced by anthropic activities) and sensitivity areas.

  15. CUBESAT-DERIVED DETECTION OF SEAGRASSES USING PLANET IMAGERY FOLLOWING UNMIXING-BASED DENOISING: IS SMALL THE NEXT BIG?

    Directory of Open Access Journals (Sweden)

    D. Traganos

    2017-05-01

    Full Text Available Seagrasses are one of the most productive and widespread yet threatened coastal ecosystems on Earth. Despite their importance, they are declining due to various threats, which are mainly anthropogenic. Lack of data on their distribution hinders any effort to rectify this decline through effective detection, mapping and monitoring. Remote sensing can mitigate this data gap by allowing retrospective quantitative assessment of seagrass beds over large and remote areas. In this paper, we evaluate the quantitative application of Planet high resolution imagery for the detection of seagrasses in the Thermaikos Gulf, NW Aegean Sea, Greece. The low Signal-to-noise Ratio (SNR, which characterizes spectral bands at shorter wavelengths, prompts the application of the Unmixing-based denoising (UBD as a pre-processing step for seagrass detection. A total of 15 spectral-temporal patterns is extracted from a Planet image time series to restore the corrupted blue and green band in the processed Planet image. Subsequently, we implement Lyzenga’s empirical water column correction and Support Vector Machines (SVM to evaluate quantitative benefits of denoising. Denoising aids detection of Posidonia oceanica seagrass species by increasing its producer and user accuracy by 31.7 % and 10.4 %, correspondingly, with a respective increase in its Kappa value from 0.3 to 0.48. In the near future, our objective is to improve accuracies in seagrass detection by applying more sophisticated, analytical water column correction algorithms to Planet imagery, developing time- and cost-effective monitoring of seagrass distribution that will enable in turn the effective management and conservation of these highly valuable and productive ecosystems.

  16. Habitat and scale shape the demographic fate of the keystone sea urchin Paracentrotus lividus in Mediterranean macrophyte communities.

    Directory of Open Access Journals (Sweden)

    Patricia Prado

    Full Text Available Demographic processes exert different degrees of control as individuals grow, and in species that span several habitats and spatial scales, this can influence our ability to predict their population at a particular life-history stage given the previous life stage. In particular, when keystone species are involved, this relative coupling between demographic stages can have significant implications for the functioning of ecosystems. We examined benthic and pelagic abundances of the sea urchin Paracentrotus lividus in order to: 1 understand the main life-history bottlenecks by observing the degree of coupling between demographic stages; and 2 explore the processes driving these linkages. P. lividus is the dominant invertebrate herbivore in the Mediterranean Sea, and has been repeatedly observed to overgraze shallow beds of the seagrass Posidonia oceanica and rocky macroalgal communities. We used a hierarchical sampling design at different spatial scales (100 s, 10 s and <1 km and habitats (seagrass and rocky macroalgae to describe the spatial patterns in the abundance of different demographic stages (larvae, settlers, recruits and adults. Our results indicate that large-scale factors (potentially currents, nutrients, temperature, etc. determine larval availability and settlement in the pelagic stages of urchin life history. In rocky macroalgal habitats, benthic processes (like predation acting at large or medium scales drive adult abundances. In contrast, adult numbers in seagrass meadows are most likely influenced by factors like local migration (from adjoining rocky habitats functioning at much smaller scales. The complexity of spatial and habitat-dependent processes shaping urchin populations demands a multiplicity of approaches when addressing habitat conservation actions, yet such actions are currently mostly aimed at managing predation processes and fish numbers. We argue that a more holistic ecosystem management also needs to incorporate the

  17. Innovative method for optimizing Side-Scan Sonar mapping: The blind band unveiled

    Science.gov (United States)

    Pergent, Gérard; Monnier, Briac; Clabaut, Philippe; Gascon, Gilles; Pergent-Martini, Christine; Valette-Sansevin, Audrey

    2017-07-01

    Over the past few years, the mapping of Mediterranean marine habitats has become a priority for scientists, environment managers and stakeholders, in particular in order to comply with European directives (Water Framework Directive and Marine Strategy Framework Directive) and to implement legislation to ensure their conservation. Side-scan sonar (SSS) is recognised as one of the most effective tool for underwater mapping. However, interpretation of acoustic data (sonograms) requires extensive field calibration and the ground-truthing process remains essential. Several techniques are commonly used, with sampling methods involving grabs, scuba diving observations or Remotely Operated Vehicle (ROV) underwater video recordings. All these techniques are time consuming, expensive and only provide sporadic informations. In the present study, the possibility of coupling a camera with a SSS and acquiring underwater videos in a continuous way has been tested. During the 'PosidCorse' oceanographic survey carried out along the eastern coast of Corsica, optical and acoustic data were respectively obtained using a GoPro™ camera and a Klein 3000™ SSS. Thereby, five profiles were performed between 10 and 50 m depth, corresponding to more than 20 km of data acquisition. The vertical images recorded with the camera fixed under the SSS and positioned facing downwards provided photo mosaics of very good quality corresponding to the entire sonograms's blind band. From the photo mosaics, 94% of the different bottom types and main habitats have been identified; specific structures linked to hydrodynamics conditions, anthropic and biological activities have also been observed as well as the substrate on which the Posidonia oceanica meadow grows. The association between acoustic data and underwater videos has proved to be a non-destructive and cost-effective method for ground-truthing in marine habitats mapping. Nevertheless, in order to optimize the results over the next surveys

  18. Propagules are not all equal: traits of vegetative fragments and disturbance regulate invasion success.

    Science.gov (United States)

    Uyà, Marc; Bulleri, Fabio; Gribben, Paul E

    2018-02-02

    Invasion success is regulated by multiple factors. While the roles of disturbance and propagule pressure in regulating the establishment of non-native species are widely acknowledged, that of propagule morphology (a proxy for quality) is poorly known. By means of a multi-factorial field experiment, we tested how the number (5 vs. 10) and quality (intact, without fronds or without rhizoids) of fragments of the clonal invasive seaweed, Caulerpa cylindracea, influenced its ability to establish in patches of the native seagrass, Posidonia oceanica, exposed to different intensities of disturbance (0, 50, or 100% reduction in canopy cover). We hypothesized that the ability of fragments to establish would be greater for intact fragments (high quality) and reduced more by frond removal (low quality) than rhizoid removal (intermediate quality). At low propagule pressure or quality, fragment establishment was predicted to increase with increasing disturbance, whereas, at high propagule pressure or quality, it was predicted to be high regardless of disturbance intensity. Disturbance intensity, fragment number and quality had independent effects on C. cylindracea establishment success. Disturbance always facilitated fragment establishment. However, fragments retaining fronds, either intact or deprived of rhizoids, had higher establishment success than fragments deprived of fronds. Increasing propagule number had weak effects on the cover of C. cylindracea. Our results demonstrate that propagule traits enabling the acquisition of resources made available by disturbance can be more important than propagule number in determining the establishment and spread of clonal non-native plants. More generally, our study suggests that propagule quality is a key, yet underexplored, determinant of invasion success. © 2018 by the Ecological Society of America.

  19. Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models

    Science.gov (United States)

    Mejía, Luz María; Paytan, Adina; Eisenhauer, Anton; Böhm, Florian; Kolevica, Ana; Bolton, Clara; Méndez-Vicente, Ana; Abrevaya, Lorena; Isensee, Kirsten; Stoll, Heather

    2018-01-01

    Coccoliths comprise a major fraction of the global carbonate sink. Therefore, changes in coccolithophores' Ca isotopic fractionation could affect seawater Ca isotopic composition, affecting interpretations of the global Ca cycle and related changes in seawater chemistry and climate. Despite this, a quantitative interpretation of coccolith Ca isotopic fractionation and a clear understanding of the mechanisms driving it are not yet available. Here, we address this gap in knowledge by developing a simple model (CaSri-Co) to track coccolith Ca isotopic fractionation during cellular Ca uptake and allocation to calcification. We then apply it to published and new δ 44 / 40 Ca and Sr/Ca data of cultured coccolithophores of the species Emiliania huxleyi and Gephyrocapsa oceanica. We identify changes in calcification rates, Ca retention efficiency and solvation-desolvation rates as major drivers of the Ca isotopic fractionation and Sr/Ca variations observed in cultures. Higher calcification rates, higher Ca retention efficiencies and lower solvation-desolvation rates increase both coccolith Ca isotopic fractionation and Sr/Ca. Coccolith Ca isotopic fractionation is most sensitive to changes in solvation-desolvation rates. Changes in Ca retention efficiency may be a major driver of coccolith Sr/Ca variations in cultures. We suggest that substantial changes in the water structure strength caused by past changes in temperature could have induced significant changes in coccolithophores' Ca isotopic fractionation, potentially having some influence on seawater Ca isotopic composition. We also suggest a potential effect on Ca isotopic fractionation via modification of the solvation environment through cellular exudates, a hypothesis that remains to be tested.

  20. Fine-Scale Cartography of Human Impacts along French Mediterranean Coasts: A Relevant Map for the Management of Marine Ecosystems.

    Science.gov (United States)

    Holon, Florian; Mouquet, Nicolas; Boissery, Pierre; Bouchoucha, Marc; Delaruelle, Gwenaelle; Tribot, Anne-Sophie; Deter, Julie

    2015-01-01

    Ecosystem services provided by oceans and seas support most human needs but are threatened by human activities. Despite existing maps illustrating human impacts on marine ecosystems, information remains either large-scale but rough and insufficient for stakeholders (1 km² grid, lack of data along the coast) or fine-scale but fragmentary and heterogeneous in methodology. The objectives of this study are to map and quantify the main pressures exerted on near-coast marine ecosystems, at a large spatial scale though in fine and relevant resolution for managers (one pixel = 20 x 20 m). It focuses on the French Mediterranean coast (1,700 km of coastline including Corsica) at a depth of 0 to 80 m. After completing and homogenizing data presently available under GIS on the bathymetry and anthropogenic pressures but also on the seabed nature and ecosystem vulnerability, we provide a fine modeling of the extent and impacts of 10 anthropogenic pressures on marine habitats. The considered pressures are man-made coastline, boat anchoring, aquaculture, urban effluents, industrial effluents, urbanization, agriculture, coastline erosion, coastal population and fishing. A 1:10 000 continuous habitat map is provided considering 11 habitat classes. The marine bottom is mostly covered by three habitats: infralittoral soft bottom, Posidonia oceanica meadows and circalittoral soft bottom. Around two thirds of the bottoms are found within medium and medium high cumulative impact categories. Seagrass meadows are the most impacted habitats. The most important pressures (in area and intensity) are urbanization, coastal population, coastal erosion and man-made coastline. We also identified areas in need of a special management interest. This work should contribute to prioritize environmental needs, as well as enhance the development of indicators for the assessment of the ecological status of coastal systems. It could also help better apply and coordinate management measures at a relevant

  1. Composition and temporal variability of particle fluxes in an insular canyon of the northwestern Mediterranean Sea

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    Grinyó, Jordi; Isla, Enrique; Peral, Laura; Gili, Josep-Maria

    2017-12-01

    Particle fluxes have been widely studied in canyons located in continental margins; conversely, particle fluxes in canyons in sediment starved margins incising small island margins have received very little attention and remain poorly understood. The Menorca Canyon is the largest canyon system in the Balearic Archipelago. Despite the high oligotrophic conditions of the Balearic Archipelago the canyon and surrounding areas host diverse communities dominated by benthic suspension feeders. Understanding the magnitude and variability of environmental factors influencing these communities thus remain crucial. In order to characterize the temporal variability of particle fluxes, analyze its geochemical and macroscopic composition and identify the main processes that modulate particle fluxes in the Menorca Canyon, one instrumented line with a sediment trap and a current meter was deployed at 430 m water depth from September 2010 to October 2012. Particle fluxes ranged between 190 and 2300 mg m2 d-1 being one of the lowest ever registered in a Mediterranean submarine canyon's head. The CaCO3 fraction was the major constituent contrasting with the general trend observed in other Mediterranean canyons. Macroscopic constituents (fecal pellets, Posidonia oceanica detritus and pelagic and benthic foraminifera) presented a wide variability throughout the sampling period and were not significantly correlated with the total mass flux. The low magnitude of the registered fluxes and the lack of correlation with the observed environmental variables (e.g., currents, winds, wave height, chlorophyll-a biomass) suggest that there is no evident controlling mechanism. However, we could infer that resuspension processes and the presence of different hydrodynamic features (e.g., eddies, interchange of water masses) condition the magnitude and composition of particle fluxes.

  2. Phytoplankton calcification as an effective mechanism to alleviate cellular calcium poisoning

    Science.gov (United States)

    Müller, M. N.; Ramos, J. Barcelos e.; Schulz, K. G.; Riebesell, U.; Kaźmierczak, J.; Gallo, F.; Mackinder, L.; Li, Y.; Nesterenko, P. N.; Trull, T. W.; Hallegraeff, G. M.

    2015-11-01

    Marine phytoplankton have developed the remarkable ability to tightly regulate the concentration of free calcium ions in the intracellular cytosol at a level of ~ 0.1 μmol L-1 in the presence of seawater Ca2+ concentrations of 10 mmol L-1. The low cytosolic calcium ion concentration is of utmost importance for proper cell signalling function. While the regulatory mechanisms responsible for the tight control of intracellular Ca2+ concentration are not completely understood, phytoplankton taxonomic groups appear to have evolved different strategies, which may affect their ability to cope with changes in seawater Ca2+ concentrations in their environment on geological timescales. For example, the Cretaceous (145 to 66 Ma), an era known for the high abundance of coccolithophores and the production of enormous calcium carbonate deposits, exhibited seawater calcium concentrations up to 4 times present-day levels. We show that calcifying coccolithophore species (Emiliania huxleyi, Gephyrocapsa oceanica and Coccolithus braarudii) are able to maintain their relative fitness (in terms of growth rate and photosynthesis) at simulated Cretaceous seawater calcium concentrations, whereas these rates are severely reduced under these conditions in some non-calcareous phytoplankton species (Chaetoceros sp., Ceratoneis closterium and Heterosigma akashiwo). Most notably, this also applies to a non-calcifying strain of E. huxleyi which displays a calcium sensitivity similar to the non-calcareous species. We hypothesize that the process of calcification in coccolithophores provides an efficient mechanism to alleviate cellular calcium poisoning and thereby offered a potential key evolutionary advantage, responsible for the proliferation of coccolithophores during times of high seawater calcium concentrations. The exact function of calcification and the reason behind the highly ornate physical structures of coccoliths remain elusive.

  3. Ecological characteristics of the invasive pufferfish Lagocephalus sceleratus (Gmelin, 1789 in the eastern Mediterranean Sea – a case study from Rhodes

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    S. KALOGIROU

    2013-04-01

    Full Text Available In this study, the ecological and societal impact of the invasive pufferfish Lagocephalus sceleratus on coastal habitats of an area of the eastern Mediterranean Sea (Rhodes Island was investigated. Seasonal quantitative samplings in two common coastal habitats were used to investigate habitat use of different life-stages. Sandy areas were found to be highly important for the early life stages of L. sceleratus. In contrast, Posidonia oceanica habitats were mainly preferred by larger (> 29 cm reproductive adults, not exceeding 64 cm. Lagocephalus sceleratus was found to feed on invertebrates and fish while size classification revealed a tendency for a diet shift with increased size. During early life stages, L. sceleratus inhabits sandy bottoms where it feeds on various invertebrates. The predominant molluscan species found in the diet of larger (> 20 cm L. sceleratus individuals were the economically important Sepia officinalis and Octopus vulgaris. The size at which 50% of individuals reach maturity was estimated to 19 cm. With increased size, habitat shift to seagrass meadows most possibly occurs to meet both the increased demand in prey availability and requirement of appropriate spawning ground. Condition factor of L. sceleratus showed significantly higher values during summer than all other seasons and this was attributed to spawning season and increase in feeding. Societal impacts were alarming due to increased public attention concerning its lethal effects (presence of tetrodotoxin, if consumed. Its high abundance in the coastal fish communities of the studied area combined with ecological and societal impacts, clearly classify L. sceleratus a pest for fisheries and potential threat for biodiversity.

  4. Ecological typologies of large areas. An application in the Mediterranean Sea.

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    de la Hoz, Camino F; Ramos, Elvira; Puente, Araceli; Méndez, Fernando; Menéndez, Melisa; Juanes, José A; Losada, Íñigo J

    2018-01-01

    One approach to identifying and mapping the state of marine biophysical conditions is the identification of large-scale ecological units for which conditions are similar and the strategies of management may also be similar. Because biological processes are difficult to directly record over large areas, abiotic characteristics are used as surrogate parameters. In this work, the Mediterranean Sea was classified into homogeneous spatial areas based on abiotic variables. Eight parameters were selected based on salinity, sea surface temperature, photosynthetically active radiation, sea-wave heights and depth variables. The parameters were gathered in grid points of 0.5° spatial resolution in the open sea and 0.125° in coastal areas. The typologies were obtained by data mining the eight parameters throughout the Mediterranean and combining two clustering techniques: self-organizing maps and the k-means algorithm. The result is a division of the Mediterranean Sea into seven typologies. For these typologies, the classification recognizes differences in temperature, salinity and radiation. In addition, it separates coastal from deep areas. The influence of river discharges and the entrance of water from other seas are also reflected. These results are consistent with the ecological requirements of the five studied seagrasses (Posidonia oceanica, Zostera marina, Zostera noltei, Cymodocea nodosa, Halophila stipulacea), supporting the suitability of the resulting classification and the proposed methodology. The approach thus provides a tool for the sustainable management of large marine areas and the ability to address not only present threats but also future conditions, such as climate change. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Future warmer seas: increased stress and susceptibility to grazing in seedlings of a marine habitat-forming species.

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    Hernán, Gema; Ortega, María J; Gándara, Alberto M; Castejón, Inés; Terrados, Jorge; Tomas, Fiona

    2017-11-01

    Increases in seawater temperature are expected to have negative consequences for marine organisms. Beyond individual effects, species-specific differences in thermal tolerance are predicted to modify species interactions and increase the strength of top-down effects, particularly in plant-herbivore interactions. Shifts in trophic interactions will be especially important when affecting habitat-forming species such as seagrasses, as the consequences on their abundance will cascade throughout the food web. Seagrasses are a major component of coastal ecosystems offering important ecosystem services, but are threatened by multiple anthropogenic stressors, including warming. The mechanistic understanding of seagrass responses to warming at multiple scales of organization remains largely unexplored, especially in early-life stages such as seedlings. Yet, these early-life stages are critical for seagrass expansion processes and adaptation to climate change. In this study, we determined the effects of a 3 month experimental exposure to present and predicted mean summer SST of the Mediterranean Sea (25°C, 27°C, and 29°C) on the photophysiology, size, and ecology (i.e., plant-herbivore interactions) of seedlings of the seagrass Posidonia oceanica. Warming resulted in increased mortality, leaf necrosis, and respiration as well as lower carbohydrate reserves in the seed, the main storage organ in seedlings. Aboveground biomass and root growth were also limited with warming, which could hamper seedling establishment success. Furthermore, warming increased the susceptibility to consumption by grazers, likely due to lower leaf fiber content and thickness. Our results indicate that warming will negatively affect seagrass seedlings through multiple direct and indirect pathways: increased stress, reduced establishment potential, lower storage of carbohydrate reserves, and increased susceptibly to consumption. This work provides a significant step forward in understanding the

  6. An evaluation of sampling methodology for assessing settlement of temperate fish in seagrass meadows

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    I. A. CATALAN

    2014-03-01

    Full Text Available All demersal fish with planktonic larvae settle at some point early in life, generally around the transformation from larvae to juveniles or soon after. Sampling pre-settlement or very young, settled fish is challenging due to spatial concretions within the habitat and the pulsed, rapid nature of the settlement process. There is a lack of robust methods that enable this sampling, but information on the settlement, that represents a mortality bottleneck, is crucial for the follow-up of populations for fisheries and conservation purposes. An empirical evaluation of sampling methods has not been conducted in temperate habitats. Here, we compare six different sampling methods to collect pre- and post-settlement stages of fish to determine the best combination of techniques to utilise in Posidonia oceanica, an endemic Mediterranean seagrass that provides a key nursery habitat for coastal fish. We considered three types of pelagic nets (bongo net, neuston net and ring net, two types of light-traps (Quatrefoil and Ecocean CARE® to sample pre-settled stages and a low-impact epibenthic trawl for recent settlers. Our results show a significantly different size-spectrum for each method, with a continuous range of sizes from 2 mm to 200 mm. The smallest sizes were collected by the bongo net, followed by the ring net, the neuston net, the Quatrefoil, the Ecocean and finally the epibenthic trawl. Our results suggest that an appropriate strategy for collecting and estimating the abundance of key littoral fish species around settlement size is the combination of the Ecocean light trap and the epibenthic trawl.

  7. A survey-based assessment of seagrass status, management and legislation in Europe

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    Carmen B. De Los Santos

    2014-06-01

    Perception of the ecological status of European seagrasses varied greatly among species and countries. Z. noltei and Z. marina got low scores in most of the countries whereas P. oceanica was rated from “moderate” to “very good” and Cymodocea nodosa got very dissimilar scores (Fig 1. Coastal development and eutrophication were reported as the mayor threats to seagrasses (Fig 2, in agreement with recent global or regional assessments (Grech et al., 2012, Marbà et al., 2014. Some of the respondent underlined the limited research background to score seagrass threats or their local particularity. Seagrasses have been reported as uncharismatic ecosystems (Duarte et al., 2008 and this was reflected in our results: scores were low for the public and policy makers and variable for managers (Fig 1. Some respondents highlighted a differential awareness among species (higher for P. oceanica than for other co-existing species. Several management and conservation instruments are, however, increasing the seagrass awareness in Europe, such as the use of seagrasses as indicators in the Water Framework Directory (WFD and the existence of volunteer-based monitoring programmes, which typically include outreach initiatives for the general public and interactions with managers (e.g. www.lifeposidoniandalucia.es, www.famar.wordpress.com. Borum et al. (2004 stated that “several countries already have established comprehensive and advanced monitoring programmes for seagrasses, but in many European countries programmes are virtually absent”. After a decade, our survey showed that seagrass monitoring effort, although increasing, is still variable or absent in some countries (Figs 2 & 3. Similarly, the mapped area of seagrass beds is very poor in many countries (Fig 2, or only presence/absence data or roughly theoretical estimations of total area are available. Seagrass mapping and/or monitoring were reported to be unorganised (specially when various local groups and/or regional

  8. Dermatite de localização atípica por Malassezia pachydermatis em um cão apresentando redução nos níveis séricos de zinco. (Relato de Caso.

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    M. B. Ribeiro

    2005-03-01

    Full Text Available RESUMO: Um animal da espécie canina, sexo feminino, raça Akita, de três anos de idade foi avaliado clinicamente, devido a dermatite e otite pruriginosas persistentes, com um ano de duração. O exame físico revelou seborréia gordurosa generalizada, crostas aderentes, alopecia focal, eritema, pápulas, liquenificação e hiperpigmentação, evidentes no dorso, cuja localização foi considerada atípica, além do ventre e da pele interdigital do membro pélvico direito, associada a otite externa bilateral com alterações similares. Foi feito o diagnóstico de malassezíase cutânea e otológica, por meio de microscopia em amostras obtidas com fita adesiva. Foi também evidenciada uma significativa redução nos níveis de zinco, através de dosagem sérica. Esse animal, que vinha sendo tratado sem sucesso com drogas fungicidas, respondeu com melhora evidente do quadro após quatro semanas de tratamento com um fármaco fungicida sistêmico, associado a suplementação dietética com um composto polivitamínico e mineral contendo alta concentração de zinco. Os resultados sugeriram que os baixos níveis de zinco tiveram um papel importante no estabelecimento da doença cutânea produzida pela Malassezia. PALAVRAS CHAVE: Malassezia., dematite, cão SUMARY: 3-year-old female Akita was clinically evaluated because of persistent pruritic dermatitis and otitis of one year’ duration. Physical examination revealed generalized waxy scale; adherent crusting; patchy alopecia; erythema; lichenification; and hyperpigmentation. The body regions most severely afected included the back, which was considered uncommon, the ventral region of the abdomen and the interdigital skin of the right pelvic limb. There was also bilateral otitis externa with similar lesions. The diagnostic of Malassezia-associated dermatitis and otitis was made by microscopic examination of skin

  9. Human vaccinia-like virus outbreaks in São Paulo and Goiás States, Brazil: virus detection, isolation and identification Surtos de vírus Vaccinia-like nos Estados de São Paulo e Goiás, Brasil: detecção, isolamento e identificação viral

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    Teresa Keico Nagasse-Sugahara

    2004-04-01

    Full Text Available Since October 2001, the Adolfo Lutz Institute has been receiving vesicular fluids and scab specimens of patients from Paraíba Valley region in the São Paulo and Minas Gerais States and from São Patricio Valley, in the Goiás State. Epidemiological data suggested that the outbreaks were caused by Cowpox virus or Vaccinia virus. Most of the patients are dairy milkers that had vesiculo-pustular lesions on the hands, arms, forearms, and some of them, on the face. Virus particles with orthopoxvirus morphology were detected by direct electron microscopy (DEM in samples of 49 (66.21% patients of a total of 74 analyzed. Viruses were isolated in Vero cell culture and on chorioallantoic membrane (CAM of embryonated chicken eggs. Among 21 samples submitted to PCR using primers for hemagglutinin (HA gene, 19 were positive. Restriction digestion with TaqI resulted in four characteristic Vaccinia virus fragments. HA nucleotide sequences showed 99.9% similarity with Cantagalo virus, described as a strain of Vaccinia virus. The only difference observed was the substitution of one nucleotide in the position 616 leading to change in one amino acid of the protein in the position 206. The phylogenetic analysis showed that the isolates clustered together with Cantagalo virus, other Vaccinia strains and Rabbitpox virus.A partir de outubro de 2001, o Instituto Adolfo Lutz tem recebido amostras de líquido vesicular e crostas de lesões de pele de pacientes das regiões do Vale do Paraíba, Estado de São Paulo e do Vale do São Patricio, Estado de Goiás. Os dados clínicos e epidemiológicos sugeriam que os surtos poderiam ser causados por Cowpox virus ou Vaccinia virus. A maioria dos pacientes era ordenhadores que tinham lesões vesicopustulares nas mãos, braços, antebraços e alguns na face. A análise por microscopia eletrônica direta (MED detectou partículas com morfologia de vírus do gênero Orthopoxvirus em amostras de 49 (66,21% pacientes dos 74

  10. Roadway management plan based on rockfall modelling calibration and validation. Application along the Ma-10 road in Mallorca (Spain)

    Science.gov (United States)

    Mateos, Rosa Maria; Garcia, Inmaculada; Reichenbach, Paola; Herrera, Gerardo; Sarro, Roberto; Rius, Joan; Aguilo, Raul

    2016-04-01

    taking into account, not only the success, but also the mistakes. We have further validated the calibrated parameters along the Ma-road using the 63 rockfall recorded during the past 18 years along the road. 81.5% of the rockfalls are well represented by STONE modelling. Results have been exploited by the Road Maintenance Service of Mallorca for the design of the following road management plan: (1) Phase 1. Short-term. Design a specific plan for the road- sections where rockfalls were registered and modelling results were obtained. A large investment will be expended for implementation of retention and protection measures. (2) Phase 2. Medium-term. Design a specific plan for the road- sections where rockfalls were registered but no modelling results were obtained. For these cases, new studies at local scale are necessary as well as the application of other modelling software which include higher resolution input data. (3) Phase 3. Long-term. Design a specific plan for the road- sections where no rockfalls were registered but modelling results were obtained. These are potential rockfall areas and local and specific ground studies are necessaries. References Mateos RM (2006) Los movimientos de ladera en la Serra de Tramuntana (Mallorca). Caracterización geomecánica y análisis de peligrosidad. PhD. Servicio de Publicaciones de la Universidad Complutense de Madrid. Madrid, 299 p. Mateos RM, García-Moreno I, Herrera G, Mulas J (2013) Damage caused by recent mass-movements in Majorca (Spain), a region with a high risk due to tourism.Landslide Science and Practice.Claudio Margottini, Paolo Canuti and KyojiSassa (Editors). Volume 7: Social and Economic Impact and Policies. 105-113. Guzzetti F, Crosta G, Detti R, Agliardi F (2002) STONE: A computer program for the three-dimensional simulation of rock-falls. Computers Geosciences. Vol. 28:1079-1093.

  11. Seasonal rockfall risk assessment along transportation network: a sample from Mallorca (Spain)

    Science.gov (United States)

    Mateos, Rosa Maria; Garcia, Inmaculada; Reichenbach, Paola; Herrera, Gerardo; Rius, Joan; Aguilo, Raul; Roldan, Francisco J.

    2014-05-01

    section of the road. For the risk analysis, four scenarios depending on the seasonal people exposition have been taken into account, considering the autumn as the season with the highest risk. This methodology can be applied to highly touristy areas such Mallorca, where the safety of the population and its visitors must be the priority of all concerned. References : Guzzetti, F., Crosta G., Detti, R. Agliardi, F., 2002: STONE: A computer program for the three-dimensional simulation of rock-falls. Computers Geosciences 28 (2002) 1079-1093. Mateos, R.M., García-Moreno, I., Azañón, J.M., 2012. Freeze-thaw cycles and rainfall as triggering factors of mass movements in a warm Mediterranean region: the case of the Tramuntana Range (Majorca, Spain). Landslides (2012), 9: 417-432. Mateos, R.M., García- Moreno, I., Herrera, G., Mulas, J., 2013b. Damage caused by recent mass-movements in Majorca (Spain), a region with a high risk due to tourism. Landslide Science and Practice. Claudio Margottini, Paolo Canuti and Kyoji Sassa (Editors). Volume 7: Social and Economic Impact and Policies. 105-113.

  12. Colonization and growth of crustose coralline algae (Corallinales, Rhodophyta on the Rocas Atoll

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    Alexandre Bigio Villas Bôas

    2005-12-01

    Full Text Available Crustose coralline algae play a fundamental role in reef construction all over the world. The aims fo this study were to identify and estimate the abundance of the dominant crustose coralline algae in shallow reef habitats, measuring their colonization, growth rates and productivity. Crusts sampled from different habitats were collected on leeward and windward reefs. Discs made of epoxy putty were fixed on the reef surface to follow coralline colonization and discs containing the dominant coralline algae were fixed on different habitats to measure the crusts' marginal growth. The primary production experiments followed the clear and dark bottle method for dissolved oxygen reading. Porolithon pachydermum was confirmed as the dominant crustose coralline alga on the Rocas Atoll. The non-cryptic flat form of P. pachydermum showed a faster growth rate on the leeward than on the windward reef. This form also had a faster growth rate on the reef crest (0.05 mm.day-1 than on the reef flat (0.01 mm.day-1. The cryptic protuberant form showed a trend, though not significant, towards a faster growth rate on the reef crest and in tidal pools than on the reef flat. Colonization was, in general, very slow as compared to that presented by other reef studies. P. pachydermum was a productive crust both in non-cryptic and cryptic habitats.As algas calcárias incrustantes exercem um papel fundamental na construção de recifes ao redor do mundo. Neste trabalho os objetivos foram: identificar e estimar a abundância da alga calcária incrustante dominante nas partes rasas do recife, verificando suas taxas de colonização, crescimento e produtividade. Crostas de diferentes habitats foram estudadas em locais a barlavento e sotavento. Discos feitos com massa epóxi foram fixados na superfície do recife para acompanhar a colonização das algas calcárias e discos contendo a alga calcária dominante foram fixados em diferentes habitats para medir o crescimento de suas

  13. Adição de colágeno em pão sem glúten elaborado com farinha de arroz

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    Carolina da Silva Graça

    2017-02-01

    Full Text Available Resumo Os portadores da doença celíaca, uma enteropatia, apresentam intolerância ao glúten e a restrição de alimentos que o contenham mostra-se eficaz na normalização da função intestinal e das manifestações clínicas. O objetivo do presente estudo foi avaliar o efeito da adição de colágeno em pó e em fibra nas características estruturais, tecnológicas e sensoriais de pães sem glúten, elaborados com farinha de arroz. Primeiramente, foram realizadas adições de 2%, 4%, 6% e 8% de colágeno, sob as formas em pó e em fibra, em pães elaborados com farinha de arroz, sendo estes avaliados quanto às suas características tecnológicas: volume específico, firmeza do miolo e cor da crosta e do miolo. O pão que apresentou as melhores características tecnológicas foi caracterizado quanto à sua composição química (proteínas, lipídios, cinzas, umidade e carboidratos, avaliado quanto às perdas decorrentes da cocção e submetido à análise sensorial. As massas cruas dos pães adicionados com o colágeno em fibra, assim como a massa do pão padrão (sem adição de colágeno, foram avaliadas através de reologia e microscopia eletrônica de varredura. A adição de colágeno aos pães elaborados com farinha de arroz não colaborou para a formação de uma rede semelhante à formada pelo glúten. O pão da formulação com 4% de colágeno em fibra apresentou as características tecnológicas mais próximas ao esperado, não diferindo significativamente quanto à composição química, do pão padrão. Por meio da análise sensorial, constatou-se que os pães sem glúten (padrão e com 4% de colágeno em fibra obtiveram aceitação sensorial superior a 75%. Conclui-se, com o estudo, que é possível adicionar colágeno em pães sem glúten, sendo que o pão adicionado de 4% de colágeno em fibra apresentou características mais próximas às do pão padrão testado.

  14. Influência do tipo de farinha de trigo na elaboração de bolo tipo inglês Influence of the type of wheat flour in the elaboration of english-type cake

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    Luiz Carlos Gutkoski

    2011-12-01

    Full Text Available A farinha de trigo destinada à produção de bolo deve apresentar baixo teor protéico, massa extensível e baixa força geral de glúten. A pesquisa objetivou avaliar a influência do tipo de farinha de trigo na elaboração de bolo tipo inglês empregando a metodologia padrão de teste laboratorial proposta pela AACC. As amostras de farinha de trigo foram coletadas aleatoriamente em moinhos de trigo da região e os demais ingredientes adquiridos no comércio local. As farinhas de trigo foram caracterizadas quanto ao teor de proteína bruta, amido danificado, alveografia e farinografia. A repetibilidade e a reprodutibilidade da metodologia foi avaliada empregando uma das farinhas. Os bolos tipo inglês foram produzidos pela mistura dos ingredientes: farinha de trigo, açúcar refinado, margarina, leite em pó, ovo desidratado, sal, fermento químico e água em condições laboratorial pré-definidas. Os bolos foram avaliados quanto ao volume específico, atividade de água, características internas, porosidade, cor da crosta e cor do miolo. Os resultados foram submetidos à análise de variância e as diferenças entre as médias comparadas entre si pelo teste de Tukey a 5% de significância. A amostra de farinha de trigo com 68 x 10-4 J se mostrou mais adequada para elaboração de bolo tipo inglês, apresentando maior volume específico e maior escore de pontos, avaliado através das características sensoriais.Wheat flours for cake production must show features such as low protein content, dough extensibility and low gluten strength. The aim of this research was to evaluate the influence of the type of wheat flour in the elaboration of English-type cake using the standard method for laboratory testing proposed by AACC. The wheat flour samples were collected at random from wheat mills in the region, and the other ingredients were obtained at the local market. The wheat flours were characterized according to their crude protein content

  15. Emergência de Haematobia irritans em fezes bovinas no município de Seropédica, Rio de Janeiro Emergence of Haematobia irritans in cattle dung pats in Seropédica county, Rio de Janeiro

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    Douglas Marques de Macedo

    2001-06-01

    Full Text Available O presente trabalho teve como objetivo estudar a emergência de Haematobia irritans em fezes de bovinos mantidas a campo e em laboratório, além de observar a presença de outros dípteros associados às massas fecais. Foram utilizados dois grupos de fezes bovinas, um à campo e outro em laboratório, sendo cada grupo formado por cinco bolos fecais frescos de tamanho mediano (cerca de 30 cm de diâmetro, aparência opaca, cor esverdeada, presença de fina crosta externa e consistência firme. As fezes foram cobertas com gaiolas de emergência de formato piramidal, apresentando na parte superior um orifício onde foi acoplado um frasco removível; a substituição das fezes foi realizada quinzenalmente. Foram coletados um total de 355 espécimens de H. irritans, sendo 151 provenientes das gaiolas mantidas no campo e 204 em laboratório. Estas diferenças deveram-se provavelmente à menores oscilações de temperatura verificadas no laboratório do que àquelas ocorridas no campo, além da ação de artrópodes predadores, competidores e parasitóides que, provavelmente, interferiram na emergência de H. irritans nas fezes bovinas mantidas no campo. Foi observado maior número de fêmeas em comparação com machos em ambas as condições investigadas. Além de H. irritans, obteve-se outros dípteros associados às fezes bovinas, pertencentes as seguintes famílias: Aulacigastridae, Muscidae, Psychodidae, Sarcophagidae, Sepsidae, Tachinidae e Ulidiidae. Sepsidae foi a mais abundante, com 5.224 exemplares do total de 8.928 dípteros obtidos, seguida por Sarcophagidae com 2.235 espécimens coletados, Muscidae com 1.357, Aulacigastridae com 54, Psychodidae com 46, Ulidiidae com 6 e Tachinidae com 5 exemplares.This study was carried out in order to investigate the emergence of adult flies of Haematobia irritans in cattle dung maintained in the field and in the laboratory, as well as other flies associated with dung pats. Two groups of cattle dung were

  16. A new rapid method for rockfall energies and distances estimation

    Science.gov (United States)

    Giacomini, Anna; Ferrari, Federica; Thoeni, Klaus; Lambert, Cedric

    2016-04-01

    and distances at the base to block and slope features. The validation of the proposed approach was conducted by comparing predictions to experimental data collected in the field and gathered from the scientific literature. The method can be used for both natural and constructed slopes and easily extended to more complicated and articulated slope geometries. The study shows its great potential for a quick qualitative hazard assessment providing indication about impact energy and horizontal distance of the first impact at the base of a rock cliff. Nevertheless, its application cannot substitute a more detailed quantitative analysis required for site-specific design of mitigation measures. Acknowledgements The authors gratefully acknowledge the financial support of the Australian Coal Association Research Program (ACARP). References Dorren, L.K.A. (2003) A review of rockfall mechanics and modelling approaches, Progress in Physical Geography 27(1), 69-87. Agliardi, F., Crosta, G.B., Frattini, P. (2009) Integrating rockfall risk assessment and countermeasure design by 3D modelling techniques. Natural Hazards and Earth System Sciences 9(4), 1059-1073. Ferrari, F., Thoeni, K., Giacomini, A., Lambert, C. (2016) A rapid approach to estimate the rockfall energies and distances at the base of rock cliffs. Georisk, DOI: 10.1080/17499518.2016.1139729.

  17. Oronasal complications in patients after transsphenoidal hypophyseal surgery Complicações oronasais em pacientes pós-abordagem hipofisária via transesfenoidal

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    Carolina Petry

    2009-06-01

    diferentes serviços de neurocirurgia há mais de 6 meses. RESULTADOS: 49 pacientes, 37/45 com macroadenoma. 14/49 submetidos a mais de uma intervenção, em 2/5 por via transesfenoidal. Abordagem transesfenoidal 92,8% via sublabial. Nenhum apresentava queixa espontânea. Com o questionário específico, 63,2% apresentaram queixas. Um apresentava fístula oronasal, outro, estenose da área de válvula nasal com deformidade nasal externa. A rinoscopia detectou alterações em 77,5% e a endoscopia nasal em 87,7%. Perfuração septal presente em 10/12 pacientes com crostas e 2 com secreção purulenta. Todos 4 pacientes submetidos a 2 abordagens transesfenoidais apresentaram perfuração do septo e sinéquias nasais. Nos casos com abordagem endonasal observaram-se sinéquias2, alteração em meato médio1 e estenose em área de válvula nasal1. Apenas 2 pacientes apresentaram avaliação normal. CONCLUSÃO: Alta incidência de complicações nasais após abordagem transesfenoidal convencional, observadas (exame e não referidas espontaneamente indicam a necessidad de investigação otorrinolaringológica complementada com endoscopia nasal sistemática nestes pacientes.

  18. Inclusão de fibra alimentar em pães isentos de glúten

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    Andressa Luciane Ceccon Saueressig

    Full Text Available Resumo Foram desenvolvidas quatro formulações de pães, isentos de glúten e com a inclusão de fibra alimentar solúvel e insolúvel, avaliando suas propriedades físicas, composição química, aceitação e intenção de compra do consumidor. O padrão (1 teve a farinha de arroz, fécula de mandioca, ovo, leite em pó, óleo de girassol, sal, açúcar, fermento biológico seco e água como ingredientes. Nos demais, a fécula foi parcialmente substituída por inulina (2, farelo de arroz desengordurado e inulina (3, e farelo de arroz desengordurado (4. A cor do pão 2 diferiu apenas na casca, que ficou menos vermelha e amarela que o 1. A inclusão do farelo de arroz proporcionou coloração mais escura, vermelha e amarela à crosta e miolo dos pães 3 e 4. A perda de peso e rendimento variaram apenas em relação ao pão 2, que teve maior perda de peso e menor rendimento, provavelmente devido ao colapso da massa, que não foi capaz de manter a estrutura na fase de crescimento. O custo dos pães com inulina foi maior, pois este ingrediente é um reconhecido prebiótico, adquirido em estabelecimentos farmacêuticos; enquanto que o custo do pão apenas com farelo diminuiu, já que se trata de um subproduto industrial, obtido da extração do óleo de arroz. Na composição química, houve incremento nos teores de cinzas, proteínas e fibra alimentar, principalmente insolúvel, nos pães 3 e 4; enquanto que o pão 2 apresentou menor teor proteico e maior teor de fibra alimentar, principalmente solúvel. Nutricionalmente, admite-se incremento do valor nutricional em detrimento de carboidratos digeríveis e do valor calórico. Sensorialmente, os pães 3 e 4 tiveram menor aceitação nos atributos cor e sabor, mas não diferiram dos pães 1 e 2 nos atributos odor e textura, e na intenção de compra dos consumidores. Conclui-se que o consumo dos pães que tiveram substituição parcial da fécula é garantia de alimento com qualidade funcional

  19. Lesões de pele em bovinos com doença granulomatosa sistêmica associada ao pastoreio de ervilhaca (Vicia spp. Skin lesions in cattle with systemic granulomatous disease associated to pasturing vetch (Vicia spp.

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    Rafael Almeida Fighera

    2005-04-01

    Full Text Available Descrevem-se as lesões cutâneas macroscópicas em 10 e histológicas em 8 vacas afetadas por doença granulomatosa sistêmica associada ao pastoreio de ervilhaca (Vicia spp.. Em todos os casos, as lesões cutâneas eram caracterizadas por múltiplas áreas coalescentes de alopecia, liquenificação e descamação. Os locais mais atingidos pela lesão de pele foram: cabeça e pescoço (10/10, tronco (4/10, períneo (3/10 e mama (2/10. Em todos os 8 casos avaliados histologicamente, as lesões se caracterizavam por dermatite perivascular superficial granulomatosa de intensidade variável. Outros achados histológicos incluíram dermatite perivascular profunda (1/8, perifoliculite (2/8, foliculite mural (3/8, hiperqueratose ortoqueratótica compacta (6/8, erosões (1/8, úlceras (2/8, microabscessos de Munro (8/8, crostas serocelulares (1/8, espongiose (4/8, degeneração hidrópica (5/8, acantólise (1/8, corpúsculos de Civatte (2/8, exocitose linfoplasmocitária (6/8, edema superficial (6/8, incontinência pigmentar (2/8, basofilia (6/8 e mineralização distrófica do colágeno (2/8, tumefação do núcleo das células endoteliais (8/8 e ectasia de glândulas sudoríparas (8/8.Gross and histopathological lesions in the skin of respectively 10 and 8 cows affected with systemic granulomatous disease associated with pasturing vetch (Vicia spp. are described. In all cases, the cutaneous lesions were characterized by multiple coalescent areas of alopecia, lichenification and desquamation. More frequently affected sites were the skin covering the head and neck (10/10, trunk (4/10, escutcheon (3/10 and mammary gland (2/10. In all 8 histologically examined cases the lesions were characterized by superficial perivascular granulomatous dermatitis of varying intensity. Other histological findings included deep perivascular dermatitis (1/8, perifoliculitis (2/8, mural foliculitis (3/8, compact orthokeratotic hyperkeratosis (6/8, erosions (1/8, ulcers (2

  20. Kinematics and geometry of structures in the southern limb of the Paraíba do Sul divergent structural fan, SE Brazil: a true transtensional shear

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    Nolan M. Dehler

    2006-06-01

    de Cisalhamento do Rio Santana. No flanco sul da divergência-em-leque, os dados estruturais sugerem uma evolução tectônica em dois estágios, sob condições de alta temperatura: um estágio precoce, envolvendo empurrões oblíquos sinistrais e movimentos tangenciais paralelos ao orógeno com cinemática de topo para SSW-SW, e um estágio tardio, envolvendo deformação transtrativa destral, com movimento de topo para NNE-NE. Propõe-se aqui um modelo de deformação heterogênea para explicar esta inversão cinemática. Neste modelo, durante a deformação progressiva, o gradiente do campo de movimento transpressivo pode variar de duas maneiras: (a por mudanças transitórias na reologia da crosta ou (b por mudanças no componente de cisalhamento puro. No estágio precoce, o material parcialmente fundido acomoda mais facilmente as deformações impostas, ocorre cisalhamento dúctil com movimento de topo para SSW-SW. À medida que ocorre o decréscimo do distúrbio termal e aumenta a razão de convergência, instala-se um regime de deformação cisalhante transtrativa com movimento de topo para NNE. Sugere-se que esta deformação transtrativa esteja relacionada a uma tectônica de extrusão associada à deformação transpressiva regional.

  1. Centro de Análise Sirgas - IBGE: novas estratégias de processamento e combinação, e a influência da mudança do referencial global nos resultados

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    Sonia Maria Alves Costa

    Full Text Available Atualmente, o SIRGAS (Sistema de Referência Geocêntrico para as Américas é realizado por uma rede GNSS (Global Navigation Satellite System permanente denominada SIRGAS-CON, com cerca de 240 estações em funcionamento permanente, distribuídas na América do Sul, Central e Caribe. Os Centros de Análise SIRGAS foram estabelecidos com a finalidade de determinar sistematicamente as coordenadas das estações SIRGAS-CON, seguindo padrões estabelecidos internacionalmente, a fim de apoiar a manutenção do sistema e as atividades do Grupo de Trabalho SIRGAS-GT I (Sistema de Referência. Desde agosto de 2008 a Coordenação de Geodésia do Instituto Brasileiro de Geografia e Estatística-IBGE assumiu oficialmente as atividades de um Centro de Análise. Este é um trabalho cuja dedicação é crescente uma vez que o número de estações no continente Sul Americano vem aumentando rapidamente nos últimos anos. Desta atividade diária são geradas dentre outros resultados, as séries temporais das coordenadas de cada estação, possibilitando assim a determinação dos deslocamentos das estações em função da movimentação da crosta terrestre, os movimentos locais como subsidência e/ou soerguimento crustal, causados por fenômenos naturais, como por exemplo, terremotos, além de efeitos sazonais causados por fatores diversos. Paralelamente a atividade de processamento dos dados GNSS, o IBGE também realiza semanalmente a combinação das soluções semanais dos nove Centros de Processamento SIRGAS. Esta combinação tem por objetivo comparar os resultados com os obtidos pelo DGFI (Deutsches Geodätisches Forschungsinstitut, o qual disponibiliza a solução final semanal da rede SIRGAS-CON. Por se tratar de resultados precisos, a mudança em alguma informação no processamento pode acarretar alterações nas coordenadas determinadas e, conseqüentemente, descontinuidades nas séries temporais de cada estação. Recentemente, em 17 de abril de

  2. Detection of rainfall-induced landslides on regional seismic networks

    Science.gov (United States)

    Manconi, Andrea; Coviello, Velio; Gariano, Stefano Luigi; Picozzi, Matteo

    2017-04-01

    this last category of events, we have applied the approach proposed in Manconi et al. (2016), in order to evaluate the performance of automatic identification, location and first order classification of landslide events trough seismic data only. Our analysis may provide important insights for the development and calibration of landslide identification algorithms, which might be used to enhance the completeness of landslide catalogues by relying on quantitative data. Brunetti, M.T., Peruccacci, S., Antronico, L., Bartolini, D., Deganutti, A.M., Gariano, S.L., Iovine, G., Luciani, S., Luino, F., Melillo, M., Palladino, M.R., Parise, M., Rossi, M., Turconi, L., Vennari, C., Vessia, G., Viero, A., and Guzzetti, F.: Catalogue of Rainfall Events with Shallow Landslides and New Rainfall thresholds in Italy, in Lollino G, Giordan D, Crosta G B, Corominas J, Azzam R, Wasowski J, Sciarra N (eds.), Engineering Geology for Society and Territory - Volume 2, Springer International Publishing, Switzerland, 1575-1579, 2015. Manconi, A., Picozzi, M., Coviello, V., De Santis, F., and Elia, L.: Real-time detection, location, and characterization of rockslides using broadband regional seismic networks, Geophys. Res. Lett., 43, 6960-6967, doi:10.1002/2016GL069572, 2016.

  3. Incidence of the autoimmune dermatosis in dogs and cats and retrospective study of 40 cases of discoid lupus erythematosus attended at the Dermatology Service of the College of Veterinary Medicine and Animal Science of UNESP – Botucatu / Incidência das dermatopatias auto-imunes em cães e gatos e estudo retrospectivo de 40 casos de lupus eritematoso discóide atendidos no serviço de dermatologia da Faculdade de Medicina Veterinária e Zootecnia da UNESP – Botucatu

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    Jéssica Correa Rodrigues

    2010-09-01

    pododermatite plasmocitária. Dos animais com lupus eritematoso discóide, todos eram da espécie canina, sendo a maioria fêmea e sem definição racial. As raças mais acometidas por lupus eritematoso discóide foram: Pastor Alemão e Akita e a média das idades foi de 56 meses. Notou-se que a maioria das lesões era localizada em plano nasal, narinas e região periocular. As lesões mais comumente observadas foram: crosta, despigmentação e eritema.

  4. Photodynamic therapy in actinic cheilitis: clinical and anatomopathological evaluation of 19 patients Tratamento de queilite actínica com terapia fotodinâmica: avaliação clínica e anatomopatológica de 19 pacientes

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    Camila Ferrari Ribeiro

    2012-06-01

    pacientes (10 homens e 9 mulheres, fototipos I a IH, idade média 62 anos. Principais efeitos adversos: dor imediata, crostas, herpes labial e edema. Escore médio de dor referida durante o procedimento foi 5,8±2,9. Na avaliação final, os pacientes referiram melhora de 80% das lesões e apresentaram mediana de 85% de satisfação (p<0,01. Análise anatomopatológica mostrou diminuição significativa de displasia (p=0,03, apesar da persistência em 84% dos casos. Não houve correlação significativa da redução no grau de displasia com impressão subjetiva de melhora clínica (p=0,82 ou com satisfação final do paciente (p=0,96. CONCLUSÃO: TFD é efetiva no tratamento da queilite actínica, porém associada a grau significativo de dor. Devido à persistência de displasia, mais estudos são necessários para definir o número ideal de aplicações para tratamento efetivo destas lesões.

  5. Evidence of mingling between contrasting magmas in a deep plutonic environment: the example of Várzea Alegre, in the Ribeira Mobile Belt, Espírito Santo, Brazil

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    SILVIA R. MEDEIROS

    2001-03-01

    . Este era previamente enriquecido em elementos incompatíveis, em ETR leves e intermediários e em alguns elementos HFS. Um segundo enriquecimento em ETR leves e elementos incompatíveis nessa série foi devido ao "mingling'' com o magma granítico crustal. Esse processo de mingling mudou a composição do magma toleiítico original para um magma cálcio-alcalino de médio-K, que produziu a suíte de rochas básicas a intermediária. O magma granítico da segunda suite cálcio-alcalina de alto-K foi originada da fusão parcial da crosta continental, mas sob forte influência dos líquidos de derivação mantélica.

  6. Esporotricosis felina: aspectos clínicos e zoonóticos Feline sporotrichosis: clinical and zoonotic aspects

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    Carlos Eduardo Larsson

    1989-10-01

    Full Text Available La esporotricosis consiste en micosis profunda, de evolución subaguda o crónica decurrente de infección por el hongo dimorfico Sporothrix schenkii. Consiste en dermatopatia mucho frecuente en nuestro medio, resultante de la penetración de abrojos e de arañazos por espinos de plantas. El S. schenkii ha sido descrito, en S. Paulo, en perros, gatos, aseninos, bovinos, equinos y ratones. Todavía, el carácter de antropozoonosis de la enfermedad pocas veces ha sido descrito tanto en la literatura internacional como en la nacional, existiendo apenas una citación en lo Brasil, de probable transmisión gato/hombre. Se discrebió, en lo presente relato, caso clínico de esporotricosis felina con transmisión através de arañadura en propietario, tratador y médico veterinário. Un gato, sin raza definida, macho, con 3 años, mucho agresivo, con grave cuadro cutáneo (cefálico, torácico y de miembros torácicos manifestado por lesiones ulceradas, exudativas de alopecia, deposición de crostas hemorrágicas, agraviado por síntomas de lo complejo respiratorio felino, donde por su temperamento agresivo habia arenado en corto espacio de tiempo 5 individuos, donde 3 de los individuos manifestaron sintomas de evolución y gravedad distintas. El diagnostico clínico presuntivo fue confirmado perlo examen histopatológico (H.E., PAS de fragmentos de piel, linfonodos y amígdalas cogidos, "intra-vitam" y/o "post-morten", per lo aislamiento de lo agente, per la inoculación en testículos de ratas adultas y posterior nuevo aislamiento. Se confirmó la patologia por pruebas suerológicas (F.C., anticuerpos precipitantes y prueba de intradermoreación (esporotriquina en los pacientes acometidos.The sporotrichosis is a deep mycosis, its course is subacute or chronic, and is caused by the Sporothrix schenckii. It's a very common dermatopathy, generally arising from thorn wounds, insects stings as well as from splinters. The S. schenckii has been described in

  7. Tratamento de feridas cutâneas extensas usando tecido dérmico acelular porcino com e sem cobertura impermeável Porcine acellular dermal graft with and without impermeable dressing to treat extensive wounds

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    Erika Hoyama

    2005-08-01

    Full Text Available FUNDAMENTOS: O tecido dérmico acelular porcino é alternativa para o tratamento de feridas cutâneas. OBJETIVOS: Avaliar a resposta clínica e inflamatória do implante de tecido dérmico acelular porcino, com e sem cobertura impermeável. MÉTODOS: Estudo pareado, longitudinal, criando-se duas feridas cutâneas no dorso de 16 ratos (quatro animais/grupo, em que foi implantado tecido dérmico acelular coberto ou não por impermeável. Os animais foram avaliados e sacrificados sete, 15, 30 e 60 dias após a cirurgia, sendo removidos os tecidos acelulares e adjacentes para avaliação histológica e morfométrica. RESULTADOS: A cobertura impermeável permaneceu sobre o tecido acelular porcino até cerca de 15 dias. O grupo sem impermeável apresentou maior desidratação, com crosta fibrinoleucocitária, edema e reação inflamatória na derme. Sessenta dias após a cirurgia, animais do grupo sem impermeável ainda apresentavam ulcerações, afinamento do epitélio e ausência de queratina, enquanto nos do grupo com impermeável a pele já se encontrava normal. CONCLUSÃO: O tecido dérmico acelular porcino com cobertura impermeável apresentou resultados clínicos e histológicos melhores do que os do tecido dérmico acelular porcino sem impermeável para tratamento de feridas cutâneas extensas.BACKGROUND: The porcine acellular dermal graft is an alternative for the treatment of skin wounds. OBJECTIVE: To evaluate the clinical and inflammatory response elicited by a porcine derived acellular dermal graft with or without an impermeable dressing. METHODS: A matched-pair longitudinal study was conducted by creating two skin wounds along the dorsal midline of 16 rats (4 rats/group with implantation of a porcine acellular dermal graft with or without an impermeable dressing. At the 7th, 15th, 30th and 60th postoperative days the animals were evaluated and sacrificed. The acellular tissue and surrounding tissues were removed for histological and

  8. Tectonics and paleogeography of the Marajó Basin, northern Brazil

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    JOÃO B. S. COSTA

    2002-09-01

    cinturões orogênicos pré-cambrianos Tumucumaque, Amapá e Araguaia. O evento neotectônico é um regime transcorrente que desenvolveu bacias transtensivas preenchidas por sedimentos marinhos rasos (Formação Pirabas e seqüências transicionais (Grupo Barreiras do Terciário Superior, seguidos por depósitos fluviais e seqüências transicionais do Quaternário, derivadas dos rios Amazoans e Tocantins e do estuário do Marajó. A paisagem atual tem morfologia tipicamente estuarina. A morfologia costeira apresenta escarpas em seqüências transicionais do Terciário Superior, enquanto no interior dominam elevações sustentadas por crosta laterítica do Pleistoceno Médio, aparadas por superfície erosiva a 70 m. No leste da Ilha do Marajó são reconhecidas várias gerações de paleocanais com seqüências estuarinas associadas, enquanto no lado oeste predomina uma planície flúvio-marinha.

  9. IAC 60 Centenário e IAC 162 Tuiuiú: cultivares de trigo para sequeiro e irrigado no Estado de São Paulo IAC 60 Centenário and IAC 162 Tuiuiú: wheat cultivars for upland and irrigated conditions in the State of São Paulo, Brazil

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    João Carlos Felício

    1991-01-01

    Full Text Available Os cultivares de trigo IAC 60 (Centenário e IAC 162 (Tuiuiú, provenientes de cruzamentos artificiais e obtidos por seleção genealógica, foram avaliados quanto à produção de grãos e às reações aos agentes causais da ferrugem-do-colmo (casa de vegetação, da ferrugem-da-folha, da helmintosporiose e da brusone na região do Vale do Paranapanema, em condições de sequeiro, e na região Norte do Estado de São Paulo, com irrigação por aspersão. Foram também avaliadas as qualidades industriais de panificação. As produções de grãos dos novos cultivares (sequeiro não diferiram dos cultivares controles BH 1146 e IAC 24, em solos com elevada acidez (AA, e do Anahuac, em solos mais férteis (BA. Com irrigação, o IAC 60 e o IAC 162 expressaram todo o seu potencial produtivo, diferindo significativamente das testemunhas IAC 24 e Anahuac. O 'IAC 60' demonstrou moderada suscetibilidade à helmintosporiose, suscetibilidade à ferrugem-da-folha e moderada resistência à brusone, enquanto o 'IAC 162' foi resistente à ferrugem-da-folha e à brusone, porém suscetível à helmintosporiose. O 'IAC 60' apresentou tolerância ao alumínio tóxico e o 'IAC 162', moderada suscetibilidade; ambos foram moderadamente suscetíveis à toxicidade de ferro e exibiram tolerância para o manganês, quando testados em soluções contendo esses elementos. Nos ensaios de panificação, os novos cultivares apresentaram valores superiores aos obtidos com pães feitos com farinha de trigo comercial (padrão. O 'IAC 162' revelou volume específico do pão superior ao 'IAC 60', mas inferior quanto às características internas (miolo e externas (crosta.In trials carried out in upland condition at the Paranapanema Valley, and under sprinkler irrigation at the North Region State of São Paulo, Brazil, the wheat cultivars IAC 60 Centenário and IAC 162 Tuiuiú originated from artificial crosses and selected by the pedigree method, were evaluated in relation to

  10. Restauração da estrutura do solo por sequências culturais implantadas em semeadura direta, e sua relação com a erosão hídrica em distintas condições físicas de superfície Restoration of the soil structure by crop sequences established in no-till, as related to water erosion in distinct surface physical conditions

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    Jeane Cruz Portela

    2010-08-01

    Full Text Available A estrutura do solo desempenha papel de destaque no crescimento de plantas e no controle da erosão e, por conseguinte, na produção de alimentos e na conservação do solo e da água. Considerando isso, realizou-se este trabalho com o objetivo de implementar e acompanhar o processo de restauração da estrutura de um solo degradado, por meio de sequências culturais (gramíneas e leguminosas de inverno e verão, dispostas nos modos de cultivo isolado e consorciado, implantadas em semeadura direta, e posteriormente verificar sua relação com as perdas de solo e água causadas pela erosão hídrica pluvial, em distintas condições físicas de superfície (solo não mobilizado, com e sem crosta; solo recém-mobilizado, por meio de escarificação e de escarificação seguida - um mês mais tarde - de gradagem; e coberturas por resíduo cultural de 100, 18 e 0 %. O estudo foi desenvolvido em campo, com chuva simulada, na EEA/UFRGS, em Eldorado do Sul (RS, de maio de 2004 a dezembro de 2007. Os testes de erosão, em número de seis e espaçados um do outro ao redor de uma semana, foram realizados de outubro a dezembro de 2007. Utilizou-se um Argissolo Vermelho distrófico típico com textura franco-argiloarenosa na camada superficial e declividade média de 0,115 m m-1; em avançado grau de degradação. As chuvas simuladas, na intensidade constante de 64 mm h-1 e com duração variando de 1 a 3 h, foram aplicadas com o aparelho simulador de braços rotativos, sendo os resultados de perda de solo e água ajustados para a duração única de chuva de 1,5 h. Foram medidos atributos de solo e planta nas parcelas experimentais e de erosão hídrica no escoamento superficial. As sequências culturais e os testes de erosão influenciaram significativamente os resultados da pesquisa, com as diferenças sendo maiores nos últimos e com as condições físicas externas ou superficiais do solo influenciando o processo erosivo mais do que as condições f

  11. Towards a palaeosalinity proxy: hydrogen isotopic fractionation between source water and lipids produced via different biosynthetic pathways in haptophyte algae

    Science.gov (United States)

    Chivall, David; M'Boule, Daniela; Heinzelmann, Sandra M.; Kasper, Sebastian; Sinke-Schoen, Daniëlle; Sininnghe-Damsté, Jaap S.; Schouten, Stefan; van der Meer, Marcel T. J.

    2014-05-01

    , K., Kienhuis, M. V. M., Langer, G., Benthien, A., and Bijma, J.: The effect of temperature, salinity and growth rate on the stable hydrogen isotopic composition of long chain alkenones produced by Emiliania huxleyi and Gephyrocapsa oceanica, Biogeosciences, 3, 113-119, doi:10.5194/bg-3-113-2006, 2006. Rontani, J. F., Prahl, F. G., and Volkman, J. K.: Re-examination of the double bond positions in alkenones and derivatives: Biosynthetic implications, J Phycol., 42, 800-813, doi:10.1111/j.1529-8817.2006.00251.x, 2006.

  12. Environmental controls on spatial variability of summer phytoplankton structure and biomass in the Bering Sea

    Science.gov (United States)

    Wang, Yu; Xiang, Peng; Kang, Jian-hua; Ye, You-yin; Lin, Geng-ming; Yang, Qing-liang; Lin, Mao

    2018-01-01

    the community was mainly dominated by Thalassiosira nordenskiöldii, Leptocylindrus danicus, Chaetoceros socialis, Chaetoceros debilis, Fragilariopsis oceanica, Nitzschia closterium and Chaetoceros furcellatus. A diatom bloom was observed near the Bering Strait in the summer of 2010 induced by high availability of nitrate particularly in the Bering Shelf, while water mass transportation mainly influenced communities in the Bering Basin and Slope. The observed fluctuation in both biomass and summer phytoplankton communities in the Bering Sea were mostly influenced by events related to the spring sea ice retreat in 2010.

  13. The Civitavecchia Coastal Environment Monitoring System (C-CEMS): an integrated approach to the study of coastal oceanographic processes

    Science.gov (United States)

    Marcelli, Marco; Piermattei, Viviana; Madonia, Alice; Bonamano, Simone; Martellucci, Riccardo; Pierattini, Alberto; Albani, Marta; Borsellino, Chiara; Zappalà, Giuseppe

    2015-04-01

    The study of the physical and biological processes of the coastal environment, characterized by high spatial and time variability, requires the adoption of multidisciplinary strategies of investigation that takes into account, not only the biotic and abiotic components of coastal marine ecosystems, but also the terrestrial, atmospheric and hydrological features linked to them. The understanding of coastal environment is fundamental to face efficiently and effectively the pollution phenomena, as expected by Marine Strategy (2008/56 EC) Directive, which is focused on the achievement of GES by 2020 in all Member States. Following these lines, the Laboratory of Experimental Oceanology and Marine Ecology (University of Tuscia) has developed a multi-platform observing network (the Civitavecchia Coastal Environment Monitoring System, C-CEMS) that operates since 2005 in the coastal marine area of Civitavecchia (northern Tyrrhenian Sea, Italy), where multiple uses (industrial, commercial and tourist activities) and high ecological values (Posidonia oceanica meadows, hard-bottom benthic communities, priority species, etc.) closely coexist. Furthermore, in the last years the Civitavecchia harbour, which is one of the main ports of Europe, has been subjected to a series of expansion works that could impact significantly on the coastal environment. The C-CEMS, implemented in the current configuration, is composed by five main modules (fixed stations, in-situ measurements and samplings, satellite observations, numerical models, GIS) which provide integrated informations to be used in different fields of the environmental research. The fixed stations system controls one weather, two water quality and two wave-buoy stations along the coast. In addition to the long term observations acquired by the fixed stations (L-TER), in situ surveys are periodically carried out for the monitoring of the physical, chemical and biological characteristics of the water column and marine sediments

  14. Ingestion Rates and Absorption Efficiencies of Abra ovata(Mollusca: Bivalvia) Fed on Macrophytobenthic Detritus

    Science.gov (United States)

    Charles, F.; Grémare, A.; Amouroux, J. M.

    1996-01-01

    Ingestion and absorption were investigated in the deposit-feeding bivalve Abra ovatafed on 14C-formaldehyde-labelled detritus derived from 11 macrophytes: Posidonia oceanica, Cystoseira compressa, Padina pavonica, Stypocaulon scoparium, Colpomenia sinuosa, Cystoseira mediterranea, Dilophus spiralis, Rissoella verruculosa, Ulva rigida, Corallina elongata andCodium vermilara . Labelling efficiency ranged from 3·2 (R. verruculosa ) to 53·0% (C. sinuosa) depending on the detritus. The stability of the labelling also varied among detritus types, and was negatively correlated with labelling efficiency. For all types of detritus, the exchanges of radioactivity between compartments were dominated by the transfer between particulate organic matter (POM) and bivalves. These transfers resulted from the interactions between the processes of ingestion, defaecation, and recycling of faeces. The coexistence of these processes together with the occasional lack of stability of the label complicated the actual determination of ingestion rates and absorption efficiencies, which necessitated the use of mathematical modelling. The model was initially composed of five compartments: Detritus, Bivalves, Dissolved organic matter (DOM), CO 2, and Faeces. Two first-order time delays were introduced to account for the production of faeces and CO 2by the bivalves. These delays resulted in the subdivision of the Bivalves compartment into three subcompartments: bivIng, bivDig, and bivAbs. The model also accounts for differences in utilization rates of detritus and faeces by the bivalves. It simulates the exchange of radioactivity between compartments and allows the quantification of ingestion and absorption efficiencies. Our results show large differences in both ingestion rates and absorption efficiencies of A. ovatafed on different types of detritus. Ingestion rates ranged between 0·16 ( C. mediterraneaand D. spiralis) and 8·65 μgOM mgDW -1 h -1( U. rigida). Absorption efficiencies ranged

  15. Lipid and DNA biomarker analyses of Narragansett Bay Sediments: Evaluating the UK'37 proxy in an Estuarine Environment

    Science.gov (United States)

    George, S. E.; Herbert, T.; Amaral-Zettler, L. A.; Richter, N.

    2017-12-01

    Long chain polyunsaturated alkenone (LCA) lipid biomarkers produced by haptophyte phytoplankton species within the Order Isochrysidales (Phylum Haptophyta) have proven exceptionally useful in paleotemperature studies by means of the Uk'37 and Uk37 indices. Two closely-related Group III haptophytes, Emiliania huxleyi and Gephyrocapsa oceanica are the primary alkenone synthesizers in the modern ocean, while freshwater systems host the distinct Group I phylotype, sometimes called the Greenland phylotype, in reference to the location of its original discovery. Group I haptophytes produce large quantities of the distinct C37:4 ketone, which acts as a chemical `fingerprint' in sediments. The utility of alkenones as a paleotemperature proxy in estuarine environments has remained largely untested, representing an under-utilized opportunity to construct high-resolution paleotemperature records from environments at the intersection of fluvial and marine systems. This uncertainty is due, in part, to the presence of multiple haptophyte groups in estuaries, resulting in a mixed alkenone signature. To determine the community composition of alkenone-producing haptophytes within Narragansett Bay, four geographically separated cores from within the Bay were analyzed for alkenones as well as haptophyte rRNA biomarker gene presence. Haptophyte rRNA genes (small and large subunit) were recovered from surface and near-subsurface samples, and in conjunction with alkenone profiles, reveal recent haptophyte community structure and alkenone production regimes throughout the Bay. A surprising result is the recovery of rRNA biomarker genes with a 100% match to the open-ocean alkenone producer E. huxleyi in locations away from large fresh water inputs to the Bay. Results of these analyses elucidate the effect of salinity and nutrient dynamics on alkenone-producing haptophyte communities and enhance applicability of long chain polyunsaturated alkenones as lipid biomarkers in estuarine

  16. ENSO related climate variability in the Gulf of California since the Last Glacial Maximum

    Science.gov (United States)

    Staines-Urias, F.; Gonzalez-Yajimovich, O.; Beaufort, L.

    2011-12-01

    Sediments from a radiocarbon-dated giant piston core recovered in the eastern tropical Pacific region (southern Gulf of California) provide a detailed record of ENSO variability in response to the climate changes occurred since the Last Glacial Maximum. Core MD02-2510 (24°38.34'N, -110°36.0'W), recovered at 410 m depth with a total length of 47 m, is characterized by the presence of extended laminated sequences and clearly defined turbidite deposits. Samples from the top 10 m, corresponding to the last 22000 years, were analyzed to estimate carbonate content and to evaluate the composition of the coccolith assemblage. Along the entire record Geophirocaspa oceanica, Emiliania Huxleyi and Florisphaera profunda are the most abundant species, corresponding to ~80% of the assemblage. Two indexes, derived from the ecological differences between the three dominant species, were created to evaluate changes in the frequency/intensity of El Niño events as well as variations in the average depth of the nutricline. Our results indicate that during the Last Glacial Maximum the frequency and amplitude of El Niño events was reduced, most probably in response to the intensification of the Pacific subtropical cell and diminished westerlies. In contrast, the Bølling-Allerød interstadial is characterized by enhanced ENSO conditions (higher sea surface temperature, deeper nutricline) associated with a northward displacement of the ITCZ. Throughout the Younger Dryas, ENSO events decline once more up to a minimum at the beginning of the Holocene, followed by a period of increased activity from 11 to 9 ka BP. In good agreement with paleorecords from tropical and subtropical areas, a decline in El Niño activity is observed during the mid-Holocene (8.5 to 6 ka BP). The suppression in ENSO activity during this interval has been associated with changes in orbital forcing. From 5 to 1.5 ka BP a steady increase in the ENSO signal is observed. Complementary records indicate that the

  17. Anthropogenic chemical cues can alter the swimming behaviour of juvenile stages of a temperate fish.

    Science.gov (United States)

    Díaz-Gil, Carlos; Cotgrove, Lucy; Smee, Sarah Louise; Simón-Otegui, David; Hinz, Hilmar; Grau, Amalia; Palmer, Miquel; Catalán, Ignacio A

    2017-04-01

    Human pressure on coastal areas is affecting essential ecosystems including fish nursery habitats. Among these anthropogenic uses, the seasonal increment in the pressure due to leisure activities such as coastal tourism and yachting is an important environmental stressor in many coastal zones. These pressures may elicit understudied impacts due to, for example, sunscreens or other seasonal pollutants. The island of Majorca, northwest Mediterranean Sea, experiences one of the highest number of tourist visits per capita in the world, thus the surrounding coastal habitat is subject to high anthropogenic seasonal stress. Studies on early stages of fishes have observed responses to coastal chemical cues for the selection or avoidance of habitats. However, the potential interferences of human impacts on these signals are largely unknown. A choice chamber was used to determine water type preference and behaviour in naïve settled juvenile gilt-head sea bream (Sparus aurata), a temperate species of commercial interest. Fish were tested individually for behavioural changes with respect to water types from potential beneficial habitats, such as seawater with extract of the endemic seagrass Posidonia oceanica, anthropogenically influenced habitats such as water extracted from a commercial and recreational harbour and seawater mixed with sunscreen at concentrations observed in coastal waters. Using a Bayesian approach, we investigated a) water type preference; b) mean speed; and c) variance in the movement (as an indicator of burst swimming activity, or "sprint" behaviour) as behavioural descriptors with respect to water type. Fish spent similar percentage of time in treatment and control water types. However, movement descriptors showed that fish in sunscreen water moved slower (98.43% probability of being slower) and performed fewer sprints (90.1% probability of having less burst in speed) compared to control water. Less evident increases in sprints were observed in harbour

  18. Variability in the carbon storage of seagrass habitats and its implications for global estimates of blue carbon ecosystem service.

    Directory of Open Access Journals (Sweden)

    Paul S Lavery

    Full Text Available The recent focus on carbon trading has intensified interest in 'Blue Carbon'-carbon sequestered by coastal vegetated ecosystems, particularly seagrasses. Most information on seagrass carbon storage is derived from studies of a single species, Posidonia oceanica, from the Mediterranean Sea. We surveyed 17 Australian seagrass habitats to assess the variability in their sedimentary organic carbon (C org stocks. The habitats encompassed 10 species, in mono-specific or mixed meadows, depositional to exposed habitats and temperate to tropical habitats. There was an 18-fold difference in the Corg stock (1.09-20.14 mg C org cm(-3 for a temperate Posidonia sinuosa and a temperate, estuarine P. australis meadow, respectively. Integrated over the top 25 cm of sediment, this equated to an areal stock of 262-4833 g C org m(-2. For some species, there was an effect of water depth on the C org stocks, with greater stocks in deeper sites; no differences were found among sub-tidal and inter-tidal habitats. The estimated carbon storage in Australian seagrass ecosystems, taking into account inter-habitat variability, was 155 Mt. At a 2014-15 fixed carbon price of A$25.40 t(-1 and an estimated market price of $35 t(-1 in 2020, the C org stock in the top 25 cm of seagrass habitats has a potential value of $AUD 3.9-5.4 bill. The estimates of annual C org accumulation by Australian seagrasses ranged from 0.093 to 6.15 Mt, with a most probable estimate of 0.93 Mt y(-1 (10.1 t. km(-2 y(-1. These estimates, while large, were one-third of those that would be calculated if inter-habitat variability in carbon stocks were not taken into account. We conclude that there is an urgent need for more information on the variability in seagrass carbon stock and accumulation rates, and the factors driving this variability, in order to improve global estimates of seagrass Blue Carbon storage.

  19. Species-level variability in extracellular production rates of reactive oxygen species by diatoms

    Directory of Open Access Journals (Sweden)

    Robin Julie Schneider

    2016-03-01

    Full Text Available Biological production and decay of the reactive oxygen species (ROS hydrogen peroxide (H2O2 and superoxide (O2- likely have significant effects on the cycling of trace metals and carbon in marine systems. In this study, extracellular production rates of H2O2 and O2- were determined for five species of marine diatoms in the presence and absence of light. Production of both ROS was measured in parallel by suspending cells on filters and measuring the ROS downstream using chemiluminescence probes. In addition, the ability of these organisms to break down O2- and H2O2 was examined by measuring recovery of O2- and H2O2 added to the influent medium. O2- production rates ranged from undetectable to 7.3 x 10-16 mol cell-1 hr-1, while H2O2 production rates ranged from undetectable to 3.4 x 10-16 mol cell-1 hr-1. Results suggest that extracellular ROS production occurs through a variety of pathways even amongst organisms of the same genus. Thalassiosira spp. produced more O2- in light than dark, even when the organisms were killed, indicating that O2- is produced via a passive photochemical process on the cell surface. The ratio of H2O¬2 to O2- production rates was consistent with production of H2O2 solely through dismutation of O2- for T. oceanica, while T. pseudonana made much more H2O2 than O2 . T. weissflogii only produced H2O2 when stressed or killed. P. tricornutum cells did not make cell-associated ROS, but did secrete H2O2-producing substances into the growth medium. In all organisms, recovery rates for killed cultures (94-100% H2O2; 10-80% O2- were consistently higher than those for live cultures (65-95% H2O2; 10-50% O2-. While recovery rates for killed cultures in H2O2 indicate that nearly all H2O2 was degraded by active cell processes, O2- decay appeared to occur via a combination of active and passive processes. Overall, this study shows that the rates and pathways for ROS production and decay vary greatly among diatom species, even between

  20. Mineralogia e gênese de argissolos das Serras do Tabuleiro/Itajaí, Estado de Santa Catarina

    Directory of Open Access Journals (Sweden)

    Italomir Brighenti

    2012-08-01

    Full Text Available As rochas do escudo cristalino, que afloram na porção centro-leste e nordeste do Estado de Santa Catarina, estão dispostas em relevo forte ondulado e montanhoso da unidade geomorfológica Serras do Tabuleiro/Itajaí. A movimentada superfície é resultante dos ciclos tecto magmático metamórficos sofridos pela crosta, responsáveis pelo retrabalhamento de rochas muito antigas formadas do Arqueano ao Proterozoico. Esse compartimento é constituído por rochas metamórficas, e informações sobre pedogênese e composição mineralógica dos solos delas derivados são escassas, fator que motivou a condução deste trabalho. Cinco perfis resultantes da pedogênese desses materiais foram estudados. O primeiro, desenvolvido de hornblendito do Complexo Granulítico de Santa Catarina (P1, foi descrito no topo de elevação em Pomerode, em condições de relevo forte ondulado. O segundo e o quinto perfis (P2 e P5, ambos desenvolvidos de granulitos máficos do mesmo complexo, respectivamente em Massaranduba e Blumenau, foram descritos na base da encosta, em relevo local ondulado. O terceiro perfil (P3, resultante da alteração de xistos do Complexo Metamórfico Brusque, foi descrito em encosta de relevo forte ondulado, em Botuverá. O quarto perfil (P4 foi fruto da pedogênese de granitoides foliados da faixa Granito-Gnáissica Faxinal, sendo descrito no terço inferior da encosta, num relevo ondulado. Foram feitas descrições gerais e morfológicas dos solos e da litologia subjacente, análises físicas e químicas de caracterização e análises mineralógicas da fração argila por difratometria de raios X (DRX, procurando avaliar as transformações sofridas pelos minerais presentes nas rochas durante a evolução dos solos. Todos os solos apresentaram alta relação textural e, ou, grau de desenvolvimento de estrutura em blocos, associada à presença de cerosidade, caracterizando a presença de horizonte diagnóstico B textural, com argila de

  1. Intoxicação por Brachiaria spp. em bovinos no Mato Grosso do Sul Brachiaria spp. poisoning in cattle in Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Roosevelt I.C. Souza

    2010-12-01

    Full Text Available Mediante a revisão dos arquivos das fichas de necropsia do Laboratório de Patologia Animal, Universidade Federal do Mato Grosso do Sul, foram estudados a epidemiologia, o quadro clínico e a patologia de 29 surtos de intoxicação por Brachiaria spp., ocorridos em bovinos de corte, no Mato Grosso do Sul, de março de 1996 a novembro de 2009. Os surtos ocorreram em todas as épocas do ano, tanto na seca quanto na chuva. Em 24 dos 29 surtos o principal sinal clínico foi a fotossensibilização e em cinco o principal sinal foi o emagrecimento progressivo. Dos 24 surtos de fotossensibilização, 11 ocorreram em pastagens de B. decumbens, dois em pastagens mistas de B. decumbens e B. brizantha, um em B. brizantha e em 10 surtos não foi informada a espécie de Brachiaria envolvida. A morbidade variou de 0,2% a 50% e a letalidade de 44,4% a 100%. Nos casos de fotossensibilização o edema de barbela foi o sinal clínico mais encontrado em bovinos, seguido de dermatite com pele espessada no flanco e períneo, retração cicatricial auricular, icterícia, corrimento ocular. crostas auriculares e oculares, e ulcerações na parte ventral da língua. Em dois surtos foram observados sinais nervosos e em um, diarréia. Nas necropsias o fígado estava aumentado de tamanho, amarelado, com padrão lobular aumentado e, ocasionalmente, com áreas esbranquiçadas e deprimidas. Os rins estavam acastanhados e a urina escura. No exame histológico do fígado encontrou-se tumefação e vacuolização de hepatócitos, proliferação de células epiteliais dos ductos biliares, retenção biliar, fibroplasia periportal discreta ou moderada e infiltrado mononuclear periportal. Todos os casos de fotossensibilização apresentaram macrófagos espumosos no parênquima hepático e em 21 foram observados cristais birrefringentes nos ductos biliares. Cinco surtos com emagrecimento progressivo dos bovinos afetados foram diagnosticados em pastagens de B. decumbens. A

  2. PREFACE: Ocean and climate changes in polar and sub-polar environments: proceedings from the 2010 IODP-Canada/ECORD summer school

    Science.gov (United States)

    St-Onge, Guillaume; Veiga-Pires, Cristina; Solignac, Sandrine

    2011-05-01

    . The subsequent set of papers review the use of planktonic foraminifers (Eynaud), diatoms (Crosta) and dinocysts (de Vernal and Rochon) in polar or sub-polar environments. These articles are followed by a paper on transfer functions (Guiot) summarizing the different approaches used to reconstruct past environmental conditions from micropaleontological proxy data. Two papers on geochemical and isotopic proxies are then presented and related to either foraminifera isotopic records (Hillaire-Marcel) in high northern latitudes or changes in ocean circulation and weathering inputs derived from radiogenic isotopes (Frank). The volume concludes with a paper on the application of visible/near infrared derivative spectroscopy to Arctic sediments (Ortiz). All the papers published in this volume benefited from the reviews of at least two reviewers, whom we thank for their valuable time and comments. We also thank the crew of the Coriolis II, and the many scientists, participants and volunteers who contributed to the summer school and made it a great success. In addition to GEOTOP and UQAM, the following institutions contributed to the organization of the summer school: ISMER, INRS-ETE, the Geological Survey of Canada, and REFORMAR. Finally, we thank Hélène Gaonac'h (UQAM) for coordinating the summer school and Anne de Vernal (UQAM) for her leadership throughout the summer school. Editors Guillaume St-Onge Canada Research Chair in Marine Geology, Institut des sciences de la mer de Rimouski (ISMER) & GEOTOP Research Center, 310 allée des Ursulines, Rimouski, Québec, Canada, G5L 3A1 Cristina Veiga-Pires FCMA - CIMA, Universidade do Algarve, Campus de Gambelas, 8000-117 Faro, Portugal Sandrine Solignac GEOTOP, Université du Québec à Montréal, PO Box 8888, succursale 'centre ville' Montréal, QC, H3C 3P8 Canada Scientists who contributed to the summer school: Hans Asnong (UQAM/GEOTOP, Canada) Gilles Bellefleur (Geological Survey of Canada-Ottawa, Canada) Anne de Vernal (UQAM

  3. Aspectos epidemiológicos e clínicos da estefanofilariose em vacas leiteiras e comparação entre métodos de diagnóstico Epidemiological and clinical features of stephanofilariasis in dairy cows and diagnosis methods confrontation

    Directory of Open Access Journals (Sweden)

    Vanessa Issuzu Miyakawa

    2009-11-01

    Full Text Available A estefanofilariose é uma doença mundialmente distribuída e caracteriza-se por lesões na pele causadas por nematódeo do gênero Stephanofilaria. Nos bovinos manifesta-se por uma dermatite crônica associada com erupção papular progredindo para nódulos, alopecia e ulceração crostosa. Apesar de reconhecida há muitos anos, há poucos estudos e relatos sobre a mesma. A literatura é particularmente escassa no Brasil. Esse trabalho teve como objetivos investigar aspectos epidemiológicos e clínicos da estefanofilariose em vacas leiteiras naturalmente acometidas e comparar dois métodos para a confirmação do diagnóstico, o exame histopatológico e o exame direto. Foram investigados aspectos clínicos relacionados à ocorrência natural da estefanofilariose em 58 vacas de leite de sete rebanhos criados nos municípios de Santana do Itararé, PR e de Itaberá, SP durante o período de janeiro de 2006 a agosto de 2008. Dois métodos foram comparados para confirmação do diagnóstico a partir de tecido colhido por biópsia da borda das lesões, o histopatológico (n=24 e o exame direto do sedimento da solução salina isotônica na qual o tecido permaneceu embebido (n=20. A maior prevalência ocorreu de dezembro a março (57% e a maioria das vacas era lactante (87,9%. As lesões se localizavam nos quartos anteriores do úbere em seu aspecto cranial (96,7%, principalmente próximo à linha média (55%. A lesão típica tinha formato circular era ulcerada com crostas e exibia exsudato sero-sanguinolento. No exame histopatológico evidenciou-se uma dermatite crônica com infiltrado mononuclear e eosinofílico. A presença do parasita não foi detectada em nenhum dos cortes examinados. O exame direto possibilitou a demonstração do agente em todas as amostras examinadas, comprovando-se como um método eficiente para a confirmação do diagnóstico.Stephanofilariasis is a worldwide disease caused by the nematode Stephanofilaria that determines

  4. Influence of solar activity on the development of calcareous nannofossils from a Middle Holocene costal paleo-ria (SW Portugal)

    Science.gov (United States)

    Hernández, Armand; Cachão, Mário; Trigo, Ricardo M.; Conceição Freitas, M.

    2015-04-01

    A 27 m long core was recovered from a present day flat-floored small fluvial valley, tributary of the Mira River (SW Portugal) allowing to span almost the complete Holocene sedimentary sequence directly overlaying Paleozoic schists and greywackes. A high resolution study of its micropaleontological content (Alday et al. 2006) was performed and 5 sedimentary stages were established: i) a coccolith-barren lower fluvial stage; ii) a coccolith intermittent lower estuarine stage; iii) a coccolith rich marine (ria) stage; iv) a coccolith intermittent upper estuarine/lagoonal stage and v) a coccolith-barren upper fluvial stage. The usefulness of calcareous nannofossils as natural tracers of the marine sedimentation contributing with valuable information for environmental reconstructions has been thoroughly demonstrated. Here, we present a high-resolution paleoenvironmental reconstruction from the interpreted marine (ria) section of the core, between 8.8k and 4.8k cal yr BP using most abundant calcareous nannofossils. Factor Analysis retrieved two major factors from the coccolith assemblages. Factor 1 (24% var.) is related to oceanic affinity community (e.g. Gephyrocapsa muellerae, Syracosphaera pulchra and Umbilicosphaera sibogae) whereas Factor 2 (23% var.) is linked to coastal neritic taxa (e.g. Ascidian spicules, Gephyrocapsa oceanica, Coccolithus pelagicus braarudii, Heliscosphaera carteri and Braarudosphaera bigelowii). These scores showed the existence of two episodes (8.8k to 7.4k and 5.8k to 5.2k cal yr BP) of marine colonization inside the paleoecological succession of the Holocene paleo-ria (8.8k and 4.8k cal yr BP). In order to establish the relationship between the solar activity and calcareous nannofossils sedimentation, cyclicity on the studied time series was investigated by performing spectral analysis on Factor 1 (F1) and Factor 2 (F2) scores. F1 score periodogram discloses three significant periodicities (460, 350 and 236-yrs) whereas F2 score

  5. PRIAMO project: a feasibility study on Sicilian sites for sea power plants in coastal waters

    Science.gov (United States)

    Ribotti, A.; Borghini, M.; Cucco, A.; De Domenico, E.; Dibenedetto, V.; Fazioli, L.; Genovese, L.; Iaria, G.; Olita, A.; Raffa, F.; Schroeder, K.; Sorgente, R.; Spanò, N.

    2012-04-01

    by the foundation at depths of 30-50 meters. The risk of vessels in transit, tides and the main currents through a fixed mooring and ship acquisitions will be analyzed starting with the first survey scheduled in January 2012. These data will be also used to validate the numerical systems. Furthermore, an analysis of the effects of the removal of soil or accumulated material from the areas of contact with the foundation (scouring) will be conducted and any recovery technique of portions of the seabed and organisms (i.e. replanting of Posidonia oceanica) will be analyzed. Then the project PRIAMO aims at developing the concept of a sustainable use of the marine environment, both with high environmental value or marginal and degraded, through the development of innovative methodologies for the proper characterization of the sites to be used for the installation of underwater turbines. This is aimed to meet the reduction of CO2 emissions required by the Kyoto Protocol and in the framework of European strategies for a competitive, sustainable, safe energy production (EU Communication on Energy Strategy 2020 and EU Council Conclusions of February 2011).

  6. Contribution of Cultural Ecosystem Services to Natural Capital in the coastal area of Civitavecchia (Latium, Italy)

    Science.gov (United States)

    Marcelli, Marco; Madonia, Alice; Tofani, Anna; Molino, Chiara; Manfredi Frattarelli, Francesco

    2017-04-01

    to improve the decision-making process on environmental issues, giving useful information on how environmental changes influence social well-being. This work focused on the valuation of CES in terms of aesthetic value, tourism, cultural heritage, recreational potential and archaeology in the coastal area of Civitavecchia, taking in account also the quantification of the hedonic value provided by marine landscape along the coast. In the study area, a great archaeological heritage (due to the presence of two UNESCO sites and copious smaller sites spread all along the coast) and the presence of priority habitat and species (Posidonia oceanica - Habitats Directive cod. 1120; Reefs - Habitats Directive cod. 1170; Pinna nobilis - Annex IV, Natura 2000; Corallium rubrum - Annex V Habitats Directive) are overlapped with human activities involving an intense use of maritime spaces. The collected data were used to calculate a provision level of CES according to their spatial distribution allowing to detect the ecosystem services hotspots which require targeted management interventions.

  7. Rapid Crustal Uplift at Birch Bay, Washington

    Science.gov (United States)

    Sherrod, B. L.; Kelsey, H. M.; Blakely, R. J.

    2010-12-01

    Geomorphology and coastal marsh stratigraphy suggest late Holocene uplift of the shoreline at Birch Bay, located northwest of Bellingham, Washington, during an earthquake on a shallow fault. LiDAR images show a raised, late Holocene shoreline along Birch Bay, with ~1 m of elevation difference between the modern shoreline and the inferred paleoshoreline. Commercial seismic reflection images reveal an anticline in Tertiary and possibly Quaternary deposits underlying Birch Bay. NW-trending magnetic anomalies are likely associated with the Birch Bay anticline and other nearby structures. Taken together, the geophysical data and lidar images suggest uplift of young deposits along a NW-trending blind reverse fault. Stratigraphy from Terrell Creek marsh, located just south of Birch Bay, shows freshwater peat buried by lower intertidal muds, indicating local submergence ~1300 yr BP. Stratigraphy of a 70-cm sediment core from Birch Bay marsh, sitting astride the anticline imaged with seismic reflection data, shows mud buried by detrital peat. One radiocarbon age from the core places the abrupt change from mud to peat prior to 1520-1700 yr BP. We divide fossil diatom assemblages straddling the mud-peat contact at Birch Bay into three zones. The oldest zone consists primarily of intertidal and marine diatoms, dominated by Paralia sulcata, Scoleoneis tumida, Grammataphora oceanica, and Gyrosigma balticum. An intermediate zone, beginning at the sharp contact between mud and overlying peat, consists of a mixture of brackish marsh and freshwater species, dominated by Diploneis interrupta, with lesser amounts of Aulacoseira sp., Pinnularia viridis, Eunotia pectinalis, and Paralia sulcata. A third and youngest zone lies in the upper half of the peat and is dominated by poorly preserved freshwater diatoms, mostly Aulacoseira cf. crassapuntata, Pinnularia viridis, P. maior, Eunotia pectinalis, and E. praerupta. Paleoecological inferences, based on distributions of modern diatoms

  8. Innovative wave energy device applied to coastal observatory systems

    Science.gov (United States)

    Marcelli, Marco; Bonamano, Simone; Piermattei, Viviana; Scanu, Sergio; Paladini de Mendoza, Francesco; Martellucci, Riccardo; Maximo, Peviani

    2017-04-01

    anchored to a dead body on the seabed, with consequent simplifications from the point of view of deployment and maintenance, resulting in further cost reduction, compared to existing systems. At last but not less important, this device produces low impacts on marine environment according to the monitoring techniques identified in the frame of the european project "Marine Renewables Infrastructure Network for Emerging Energy Technologies" (Marinet - FP7). Within this context the device finds an excellent application field in the low consumption monitoring systems which can be located near the priority habitats to analyse the impacts due to coastal anthropic pressures. Civitavecchia coastal zone is suitable to be used as the test site for this new device as it includes the observing system C-CEMS (Bonamano et al. 2016), composed by three water quality fixed stations that continuously measure the physical, chemical and biological parameters of the water column, and Sites of Community Importance (SCI) where effective and urgent management measures were requested by the EC to protect the Posidonia oceanica meadows.

  9. On the annual cycle of the sea surface temperature and the mixed layer depth in the Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, V.M.; Villanueva, E.E.; Adem, J. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, UNAM, Mexico, D.F. (Mexico)

    2005-04-01

    Mexico. El modelo se basa en las ecuaciones de conservacion de energia termica y mecanica, esta ultima derivada de la teoria de Graus Turner, ambas ecuaciones estan acopladas de integradas verticalmente en la capa de mezcla. Las ecuaciones del modelo se resuelven en una malla regular de 25 km en el Golfo de Mexico, la region noroeste del Mar Caribe y la costa este de Florida. La velocidad de la corriente oceanica superficial y las variables atmosfericas son prescritas en el modelo usando valores observados. Mostramos la importancia que tiene el bombeo de Ekman en la velocidad de penetracion turbulenta. Encontramos que la surgencia tiene un papel importante en incrementar la penetracion turbulenta produciendo un enfriamiento del agua superficial y una disminucion en la profanidad de la capa de mezcla en la Bahia de Campeche. En el resto del Golfo el hundimiento tiende a reducir la penetracion turbulenta y a incrementar la temperatura de la superficie y la profundidad de la capa de mezcla. Una comparacion del ciclo anual de la SST y de la MLD calculados con el modelo muestra concordancia con las correspondientes observaciones reportadas por Robinson (1973). En la region profunda del Golfo de Mexico, los datos de concentracion de pigmentos fotosinteticos, obtenidos de analisis ambientales, muestran en enero, abril, mayo, junio y septiembre correlacion significativa con el ciclo anual de la velocidad de penetracion vertical turbulenta calculada.

  10. Use of seagrass meadows as an adaptation measure to climate change for reducing port agitation

    Science.gov (United States)

    Sánchez-Arcilla, Agustín; Lin, Jue; Pau Sierra, Joan; Gracia, Vicenç; Casas-Prat, Merce; Virgili, Marc

    2014-05-01

    the obtained wave projections to identify harbours where wave oscillation is expected to have a negative effect. One of these harbours, where agitation clearly increases, is selected to study the effectiveness of sea-grass for reducing wave heights within the harbour. Moreover, a sensitivity analysis is carried out to relate wave height decrease with sea-grass parameters such as meadow surface, plant density or submergence ratio (ratio between water depth and stem length). Acknowledgments The work described in this publication was supported by the European Community's Seventh Framework Programme through the grant to the budget of the Collaborative Project RISES-AM-, Contract FP7-ENV-2013-two-stage-603396. References Casas-Prat M, Sierra JP (2012). Trend analysis of wave direction and associated impacts on the Catalan Coast. Climatic Change 115:667-691. Casas-Prat M, Sierra JP (2013). Projected future wave climate in the NW Mediterranean Sea. Journal of Geophysical Research: Oceans 118:3548-3568. Koftis T, Prinos P, Stratigaki V (2013). Wave damping over artificial posidonia oceanica meadow: A large-scale experimental study. Coastal Engineering 73:71-83.

  11. Fotossensibilização em ovinos associada à ingestão de Brachiaria brizantha no estado do Pará Photosensitization of sheep kept on Brachiaria brizantha pasture in the state of Pará

    Directory of Open Access Journals (Sweden)

    Tatiane Teles Albernaz

    2010-09-01

    Full Text Available Foram estudados dois surtos e realizado um experimento de fotossensibilização associada à ingestão por Brachiaria brizantha em ovinos mestiços de Santa Inês e Dorper, com idade variando de dois a três meses, em uma fazenda no município de Santa Luzia do Pará. Esses animais foram mantidos desde o nascimento até aproximadamente dois meses de idade, em apriscos suspensos do chão, recebendo capim-elefante roxo (Pennisetum purpureum cv. roxo, concentrado, sal mineral e água ad libitum. Após esse período foram introduzidos em um piquete de B. brizantha. Na ocasião dos surtos e do experimento a fazenda foi visitada para observação dos dados epidemiológicos, avaliação clínica dos animais, colheita de amostras de sangue para dosagem de GGT, AST, BD, BI, BT, ureia e creatinina e colheita de pastagem para pesquisa de Pithomyces chartarum e saponinas. Também foi realizada necropsia com colheita de material para estudo histológico. O surto 01 ocorreu na época de escassez de chuva, com taxa de morbidade e letalidade de 43,4% e 81,6%, respectivamente. O surto 02 aconteceu no início da época chuvosa, com taxas de morbidade e letalidade de 16,3% e 76,9%, respectivamente. Em ambos os surtos o capim encontrava-se com massa residual reduzida e senescente. Dos 50 animais do experimento, 10 receberam 200ml de fluido ruminal retirado de ovelhas mães do mesmo lote, a primeira administração foi feita um dia antes da introdução desses animais na pastagem, e mais duas subsequentes com intervalo de uma semana. Após 15 dias de pastejo, os animais começaram a apresentar inquietação, procura por sombra, edema nas orelhas, mucosas amareladas, apatia, anorexia e desprendimento da pele seguido por formação de crostas em algumas áreas do corpo. Tanto os animais dos surtos quanto do experimento apresentaram aumento nos níveis de GGT, AST, BD, BI, BT, ureia e creatinina. Os valores de ureia e GGT dos animais que receberam fluido ruminal e dos

  12. Palynology and paleoecology of Sarcheshmeh and Sanganeh formations at Baghak section (east of Kopeh-Dagh

    Directory of Open Access Journals (Sweden)

    Mahjooneh Keshmiri

    2014-11-01

    calculated in five purview and then the percent of each palynological elements were acquired. 3- Discussion, Results and Conclusion All of the 50 rock samples prepared have yielded dinofalgellate cysts. The assemblages recorded include such taxa as: Acomosphaera sp., Achomosphaera neptunii, Batioladinium sp., Bourkidinium granulatum, Cauca parva, Circulodinium sp., Circulodinium brevispinosum, Circulodinium distinctum, Cometodinium sp., Coronifera oceanica, Cribroperidinium sp., Cribroperidinium orthoceras, Florentinia sp., Florentinia cooksoniae, Florentinia mantelii, Glaphyrocysta sp., Gonyaulacysta sp., Gonyaulacysta polythyris, Hystrichosphaeridium sp., Kiokansium sp., Kiokansium polypes, Klithrosphaeridium sp., Muderongia sp., Muderongia tabulate, Odontochitina operculata, Oligosphaeridium complex, Oligosphaeridium poculum, Oligosphaeridium porosum, Oligosphaeridium totum, Paleoperidinium cretaceum, Prolixosphaeridium sp., Prolixosphaeridium parvispinium, Pseudoceratium sp., Pseudoceratium retusum, Pterodinium sp., Spiniferites sp., Spiniferites ramosus, Subtilisphaera sp., Systematophora sp., Tanyosphaeridium sp. (Plate 1-2. Based on the presence of the index dinoflagellate cyst, Odontochitina operculata throughout the entire section, it can be concluded that the first appearance of this species is before the first sample of the Sarcheshmeh Formation (sample 398 and therefore the identified dinoflagellate cysts are a part of the Odontochitina operculata Zone. This palynozone originally erected by Wilson (1984 for Aptian strata in New Zealand and Morgan (1980 suggest the age of Aptian for Odontochitina operculata Zone. The presence of species Gonyaulacysta polythyris, Circulodinium brevispinosum and Florentinia mantelii which are recorded from early Aptian strata in different part of the world such as Australia (Backhouse, 1988, France (Stover, 1996, south of Alpine Italia (Torricelli,2000 and south of Tanzania (Schrank & Mahmoud, 2002 in lower formation reveal the age

  13. Tropical cooling of the ocean surface during the Last Glacial Maximum

    Science.gov (United States)

    Bard, Edouard

    2013-04-01

    Many studies have shown the importance of a correct evaluation of the mean tropical cooling to estimate the relative impact of climate forcings during the LGM, notably the effect of lower concentrations of atmospheric greenhouse gases, and in turn, have applied these results to quantify the so-called equilibrium climate sensitivity (ECS) to a CO2 doubling. Several geochemical paleothermometers have been used to estimate the tropical sea surface temperatures (e.g. SST based on alkenones and magnesium/calcium ratios measured in ocean sediments) that can be compared with model estimates (e.g. Bard 1999 Science for a short discussion). For alkenones, the TEMPUS group (Rosell-Mele et al. 2004 GRL) and MARGO group (Waelbroeck et al. Nat. Geo. 2009) used a linear equation of UK37' vs. SST based on the global core top calibration compiled by Müller et al. (1998 GCA). This calibration is indistinguishable from the original calibration based on Emiliana huxleyi cultures (Prahl et al. 1988 GCA). However, it has also been shown that the warm end of the UK37' calibration is flatter than indicated by a single straight line over the full SST range. For the warm end, this started with our study by Sonzogni et al. (1997 QR) based on low-latitude core tops from the Indian Ocean including samples representing SST between 24 and 30°C. This UK37' versus SST linear equation has a reduced slope (0.023/°C) when compared to that (0.033/°C) derived from the linear equation based on core tops compiled from all oceans (Müller et al. 1998). Support for this complexity also comes from close inspection of the global compilation by Müller et al., suggesting that the relationship flattens out at high temperatures (see also Pelejero & Calvo 2003 G3). In addition, culture studies of different strains of Gephyrocapsa oceanica and E. huxleyi (Conte et al., 1998 GCA) and measurements of sinking particulate matter from Bermuda (Conte et al. 2001 GCA) strongly suggest that the real shape of the UK

  14. Perdas de solo e água por erosão hídrica influenciadas por métodos de preparo, classes de declive e níveis de fertilidade do solo Soil and water losses by rainfall erosion influenced by tillage methods, slope-steepness classes, and soil fertility levels

    Directory of Open Access Journals (Sweden)

    N. P. Cogo

    2003-08-01

    Full Text Available A erosão é a forma mais prejudicial de degradação do solo. Além de reduzir sua capacidade produtiva para as culturas, ela pode causar sérios danos ambientais, como assoreamento e poluição das fontes de água. Contudo, usando adequados sistemas de manejo do solo e bem planejadas práticas conservacionistas de suporte, os problemas de erosão podem ser satisfatoriamente resolvidos. Com o propósito de obter informações quantitativas sobre o assunto, para servirem de guia nos planejamentos conservacionistas de uso da terra, realizou-se um experimento de erosão sob chuva natural, em Latossolo Vermelho distroférrico típico textura muito argilosa, no município de Santo Ângelo, região das Missões (RS, de dezembro de 1994 a maio de 1996, objetivando quantificar as perdas de solo e água causadas por erosão hídrica. Os tratamentos consistiram dos métodos de preparo do solo convencional, reduzido e semeadura direta, avaliados sob as condições "solo com fertilidade corrigida" nas classes de declividade de 0-0,04; 0,04-0,08 e 0,08-0,12 m m-1 (com gradientes médios de, respectivamente, 0,035; 0,065 e 0,095 m m-1 e "solo com fertilidade atual" na classe de declividade de 0,04-0,08 m m-1. As operações de preparo do solo e semeadura foram efetuadas todas transversalmente ao declive, exceto para o tratamento-testemunha (preparo convencional, sem cultivo, continuamente descoberto e sem crosta, no qual as operações de aração e gradagem foram realizadas no sentido do declive. A seqüência de culturas utilizada na avaliação da erosão foi constituída de dois ciclos culturais de soja (Glycine max, L., no período de primavera-verão de 1994/95 e 1995/96, e um de aveia preta (Avena strigosa, S., no período de outono-inverno de 1995. O índice de erosividade das chuvas (EI30 calculado no período experimental (1,5 ano foi de 10.236 MJ mm ha-1 h-1 e concentrou-se, repetidamente, em 1995 e 1996, nos meses de janeiro a março, perfazendo

  15. Fractional and fractal dynamics approach to anomalous diffusion in porous media: application to landslide behavior

    Science.gov (United States)

    Martelloni, Gianluca; Bagnoli, Franco

    2016-04-01

    and physical applications, Physics reports, 195(4-5), 127293, 1990. [27] P.-G. de Gennes, Scaling Concepts in Polymer Physics, Cornell University Press, Ithaca, 1979. [28] M. Doi, S.F. Edwards, The Theory of Polymer Dynamics, Clarendon Press, Oxford, 1986. [29] M. Porto, A. Bunde, S. Havlin, H.E. Roman, Phys. Rev. E 56 (2), 1997. [30] P. Allegrini, M. Buiatti, P. Grigolini, B. J. West, Non-Gaussian statistics of anomalous diffusion: The DNA sequences of prokaryotes, Physical Review E 58(3), 1998. [31] M. Bologna, C. Tsallis, P. Grigolini, Anomalous diffusion associated with nonlinear fractional derivative Fokker-Planck-like equation: Exact time-dependent solutions, Physical Review E, 62(2), 2000. [32] W. Chen, H. Sun, X. Zhang, D. Korosak, Anomalous diffusion modeling by fractal and fractional derivatives, Computers and Mathematics with Applications, 59, 1754-1758, 2010. [33] V.E. Tarasov, Fractional Hydrodynamic Equations for Fractal Media, Annals of Physics, 318(2), 286-307, 2005. [34] G. Martelloni, S. Segoni, R. Fanti, F. Catani, Rainfall thresholds for the forecasting of landslide occurrence at regional scale. Landslides Journal, 9(4), 485-495, 2012. [35] M.G. Anderson, S. Howes, Development and application of a combined soil water-slope stability model, Q. J. Eng. Geol. London, 18: 225-236, 1985. [36] R.M. Iverson, Landslide triggering by rain infiltration, Water Resources Research 36(7): 1897-1910, 2000. [37] N. Lu, J. Godt, Infinite slope stability under steady unsaturated seepage conditions, Water Resources Research, Vol. 44, W11404, doi:10.1029/2008WR006976, 2008. [38] W. Wu, R.C. Sidle, A Distributed Slope Stability Model for Steep Forested Basins, Water Resour. Res., 31(8), 2097-2110, doi:10.1029/95WR01136, 1995. [39] G.B. Crosta, P. Frattini, Distributed modelling of shallow landslides triggered by intense rainfall, Natural Hazards and System Sciences 3: 81-93, 2003. [40] A. Patra, A. Bauer, C. Nichita, E. Pitman, M. Sheridan, M. Bursik, et al., Parallel

  16. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    Science.gov (United States)

    László, M.

    2009-04-01

    cultura da batata podem ser de ordem agronómica, economica e comercial. Como exemplos destes podem ser citados: o uso racional de matérias orgânicos, esterco de curral e inorgânico fertilizantes. Efeito de materias orgnicânicos e N, P, K elementos minerais para produção da batata As necessidades em N, P, e K elementos minerais da batata são superidas pela aplicação apropriada de matérias orgânicos, esterco de currals, fertilizantes ao solo, combinada com a ambiente (Márton 2001a., 2001b.), época adequada e posição ideal de aplicá- lo. Efeito da materias orgânicos O suprimento de N á batateira provém principalmente da matéria orgânica do solo e do fertilizante aplicado (László 2000a., Márton et all. 2000.). Embora não seja muito praticado no Brasíl, a incorporação de esterco ao solo é fator de aumento da produção de tuberculos. Este resultado favorável poderia ser atribuído ao melhoramento da estrutura do solo, á maior retenção de água pelo e mesmo favorecendo o melhor desenvolvimento do sistema radicular da planta. A batata pode ser cultivada em todo tipo de solo desde que tenha boa drenagem e seja bem estruturado. Isto é tem que ser bem aerado e permitir o bom desenvolvimento dos órgãos subterráneos da batateira. Sem de matéria orgânicos e esterco de curral a tendencia de determinados solos formar crosta, oferecendo uma alta resisténcia mecánica á emergéncia das plantas, pode ser um determinante de stands desuniformes. A cause primaria da formação de crostas é a destruição dos agregados do solo pela excessiva manipulação mecánica resultando em aeração reduzida e aumento da densidade e coesão das particulas do solo. O encrostamento do solo pode ser reduzido através com matérias orgânicos. De maneira geral, a produção de tuberculos em solo de baixa potencialidade (aqueles em que a penetração das raizes é dificultada pela compactação, textura argilosa ou com camadas no solo) será menor do que nagueles com