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Sample records for beggiatoa spp mat

  1. Motility patterns of filamentous sulfur bacteria, Beggiatoa spp

    DEFF Research Database (Denmark)

    Dunker, Rita; Røy, Hans; Kamp, Anja;

    2011-01-01

    The large sulfur bacteria, Beggiatoa spp., live on the oxidation of sulfide with oxygen or nitrate, but avoid high concentrations of both sulfide and oxygen. As gliding filaments, they rely on reversals in the gliding direction to find their preferred environment, the oxygen–sulfide interface...

  2. Motility patterns of filamentous sulfur bacteria, Beggiatoa spp

    DEFF Research Database (Denmark)

    Dunker, Rita; Røy, Hans; Kamp, Anja;

    2011-01-01

    The large sulfur bacteria, Beggiatoa spp., live on the oxidation of sulfide with oxygen or nitrate, but avoid high concentrations of both sulfide and oxygen. As gliding filaments, they rely on reversals in the gliding direction to find their preferred environment, the oxygen–sulfide interface. We...

  3. Lipid biomarkers and carbon isotope signatures of a microbial (Beggiatoa) mat associated with gas hydrates in the gulf of Mexico.

    Science.gov (United States)

    Zhang, Chuanlun L; Huang, Zhiyong; Cantu, James; Pancost, Richard D; Brigmon, Robin L; Lyons, Timothy W; Sassen, Roger

    2005-04-01

    White and orange mats are ubiquitous on surface sediments associated with gas hydrates and cold seeps in the Gulf of Mexico. The goal of this study was to determine the predominant pathways for carbon cycling within an orange mat in Green Canyon (GC) block GC 234 in the Gulf of Mexico. Our approach incorporated laser-scanning confocal microscopy, lipid biomarkers, stable carbon isotopes, and 16S rRNA gene sequencing. Confocal microscopy showed the predominance of filamentous microorganisms (4 to 5 mum in diameter) in the mat sample, which are characteristic of Beggiatoa. The phospholipid fatty acids extracted from the mat sample were dominated by 16:1omega7c/t (67%), 18:1omega7c (17%), and 16:0 (8%), which are consistent with lipid profiles of known sulfur-oxidizing bacteria, including Beggiatoa. These results are supported by the 16S rRNA gene analysis of the mat material, which yielded sequences that are all related to the vacuolated sulfur-oxidizing bacteria, including Beggiatoa, Thioploca, and Thiomargarita. The delta13C value of total biomass was -28.6 per thousand; those of individual fatty acids were -29.4 to -33.7 per thousand. These values suggested heterotrophic growth of Beggiatoa on organic substrates that may have delta13C values characteristic of crude oil or on their by-products from microbial degradation. This study demonstrated that integrating lipid biomarkers, stable isotopes, and molecular DNA could enhance our understanding of the metabolic functions of Beggiatoa mats in sulfide-rich marine sediments associated with gas hydrates in the Gulf of Mexico and other locations. PMID:15812044

  4. Cultivated Beggiatoa spp. define the phylogenetic root of morphologically diverse, noncultured, vacuolate sulfur bacteria.

    Science.gov (United States)

    Ahmad, Azeem; Kalanetra, Karen M; Nelson, Douglas C

    2006-06-01

    Within the last 10 years, numerous SSU rRNA sequences have been collected from natural populations of conspicuous, vacuolate, colorless sulfur bacteria, which form a phylogenetically cohesive cluster (large-vacuolate sulfur bacteria clade) in the gamma-Proteobacteria. Currently, this clade is composed of four named or de facto genera: all known Thioploca and Thiomargarita strains, all vacuolate Beggiatoa strains, and several strains of vacuolate, attached filaments, which bear a superficial similarity to Thiothrix. Some of these vacuolate bacteria accumulate nitrate for respiratory purposes. This clade encompasses the largest known prokaryotic cells (Thiomargarita namibiensis) and several strains that are important in the global marine sulfur cycle. Here, we report additional sequences from five pure culture strains of Beggiatoa spp., including the only two cultured marine strains (nonvacuolate), which firmly establish the root of this vacuolate clade. Each of several diverse metabolic motifs, including obligate and facultative chemolithoautotrophy, probable mixotrophy, and seemingly strict organoheterotrophy, is represented in at least one of the nonvacuolate strains that root the vacuolate clade. Because the genus designation Beggiatoa is interspersed throughout the vacuolate clade along with other recognized or de facto genera, the need for taxonomic revision is clear. PMID:16788728

  5. Organic Nutrition of Beggiatoa sp

    OpenAIRE

    1981-01-01

    Culture OH-75-B of Beggiatoa sp. differed significantly from any described previously in its utilization of organic carbon and reduced sulfur compounds. It deposited internal sulfur granules characteristic of Beggiatoa sp. with either sulfide or thiosulfate in the medium. This strain (OH-75-B, clone 2a) could be grown in agitated liquid cultures on mineral medium with acetate as the only source of organic carbon. The resultant growth yields and rates were comparable to those for typical heter...

  6. Oxidation of Molecular Hydrogen by a Chemolithoautotrophic Beggiatoa Strain

    Science.gov (United States)

    2016-01-01

    ABSTRACT A chemolithoautotrophic strain of the family Beggiatoaceae, Beggiatoa sp. strain 35Flor, was found to oxidize molecular hydrogen when grown in a medium with diffusional gradients of oxygen, sulfide, and hydrogen. Microsensor profiles and rate measurements suggested that the strain oxidized hydrogen aerobically when oxygen was available, while hydrogen consumption under anoxic conditions was presumably driven by sulfur respiration. Beggiatoa sp. 35Flor reached significantly higher biomass in hydrogen-supplemented oxygen-sulfide gradient media, but hydrogen did not support growth of the strain in the absence of reduced sulfur compounds. Nevertheless, hydrogen oxidation can provide Beggiatoa sp. 35Flor with energy for maintenance and assimilatory purposes and may support the disposal of internally stored sulfur to prevent physical damage resulting from excessive sulfur accumulation. Our knowledge about the exposure of natural populations of Beggiatoaceae to hydrogen is very limited, but significant amounts of hydrogen could be provided by nitrogen fixation, fermentation, and geochemical processes in several of their typical habitats such as photosynthetic microbial mats and submarine sites of hydrothermal fluid flow. IMPORTANCE Reduced sulfur compounds are certainly the main electron donors for chemolithoautotrophic Beggiatoaceae, but the traditional focus on this topic has left other possible inorganic electron donors largely unexplored. In this paper, we provide evidence that hydrogen oxidation has the potential to strengthen the ecophysiological plasticity of Beggiatoaceae in several ways. Moreover, we show that hydrogen oxidation by members of this family can significantly influence biogeochemical gradients and therefore should be considered in environmental studies. PMID:26896131

  7. Diversity and distribution in hypersaline microbial mats of bacteria related to Chloroflexus spp

    DEFF Research Database (Denmark)

    Nübel, Ulrich; Bateson, Mary M.; Madigan, Michael T.; Kühl, Michael; Ward, David M.

    2001-01-01

    primers for the specific amplification of 16S rRNA genes from filamentous phototrophic bacteria within the kingdom of "green nonsulfur bacteria." PCR products recovered from microbial mats in a saltern in Guerrero Negro, Mexico, were subjected to cloning or denaturing gradient gel electrophoresis and then......Filamentous bacteria containing bacteriochlorophylls c and a were enriched from hypersaline microbial mats. Based on phylogenetic analyses of 16S rRNA gene sequences, these organisms form a previously undescribed lineage distantly related to Chloroflexus spp. We developed and tested a set of PCR...... sequenced. We found evidence of a high diversity of bacteria related to Chloroflexus which exhibit different distributions along a gradient of salinity from 5.5 to 16%....

  8. Filamentous sulfur bacteria of activated sludge: characterization of Thiothrix, Beggiatoa, and Eikelboom type 021N strains.

    OpenAIRE

    Williams, T. M.; Unz, R F

    1985-01-01

    Seventeen strains of filamentous sulfur bacteria were isolated in axenic culture from activated sludge mixed liquor samples and sulfide-gradient enrichment cultures. Isolation procedures involved plating a concentrated inoculum of washed filaments onto media containing sulfide or thiosulfate. The isolates were identified as Thiothrix spp., Beggiatoa spp., and an organism of uncertain taxonomic status, designated type 021N. All bacteria were gram negative, reduced nitrate, and formed long, mul...

  9. Filamentous sulfur bacteria of activated sludge: characterization of Thiothrix, Beggiatoa, and Eikelboom type 021N strains.

    Science.gov (United States)

    Williams, T M; Unz, R F

    1985-04-01

    Seventeen strains of filamentous sulfur bacteria were isolated in axenic culture from activated sludge mixed liquor samples and sulfide-gradient enrichment cultures. Isolation procedures involved plating a concentrated inoculum of washed filaments onto media containing sulfide or thiosulfate. The isolates were identified as Thiothrix spp., Beggiatoa spp., and an organism of uncertain taxonomic status, designated type 021N. All bacteria were gram negative, reduced nitrate, and formed long, multicellular trichomes with internal reserves of sulfur, volutin, and sudanophilic material. Thiothrix spp. formed rosettes and gonidia, and four of six strains were ensheathed. Type 021N organisms utilized glucose, lacked a sheath, and differed from Thiothrix spp. in several aspects of cellular and cultural morphology. Beggiatoa spp. lacked catalase and oxidase, and filaments were motile. Biochemical and physiological characterization of the isolates revealed important distinguishing features between the three groups of bacteria. Strain differences were most evident among the Thiothrix cultures. A comparison of the filamentous sulfur bacteria with freshwater strains of Leucothrix was made also. PMID:4004221

  10. Thioploca spp: filamentous sulfur bacteria with nitrate vacuoles

    DEFF Research Database (Denmark)

    Jørgensen, BB; Gallardo, VA

    1999-01-01

    Thioploca spp. are multicellular, filamentous, colorless sulfur bacteria inhabiting freshwater and marine sediments. They have elemental sulfur inclusions similar to the phylogenetically closely related Beggiatoa, but in contrast to these they live in bundles surrounded by a common sheath. Vast...

  11. Use of reduced sulfur compounds by Beggiatoa sp.

    OpenAIRE

    Nelson, D. C.; Castenholz, R W

    1981-01-01

    A strain of Beggiatoa cf. leptomitiformis (OH-75-B, clone 2a) was isolated which is unique among reported strains in its ability to deposit internal sulfur granules from thiosulfate. It also deposited these characteristic granules (as all BEggiatoa species do) from sulfide. In cultures where growth was limited by exhaustion of organic substrates, these granules generally comprised about 20% of the total cell weight. With medium containing acetate and thiosulfate, no measurable utilization of ...

  12. Growth and nitrate reduction of Beggiatoa filaments studied in enrichment cultures

    DEFF Research Database (Denmark)

    Kamp, Anja

    In this thesis, several aspects of the gliding, filamentous, colourless sulphur bacteria Beggiatoa were investigated. The first part of this thesis addressed the growth mode, breakage of filaments for multiplication, and movement directions of filaments of Beggiatoa. Marine Beggiatoa were enriche...

  13. Biological and chemical sulfide oxidation in a Beggiatoa inhabited marine sediment

    DEFF Research Database (Denmark)

    Preisler, André; de Beer, Dirk; Lichtschlag, Anna;

    2007-01-01

    gradient and corresponding high sulfide flux, a typical characteristic of Beggiatoa habitats, is not needed for their metabolic performance, but rather used as a chemotactic cue by the highly motile filaments to avoid getting lost at depth in the sediment. Indeed sulfide is a repellant for Beggiatoa...... and corresponding high sulfide flux, a typical characteristic of Beggiatoa habitats, is not needed for their metabolic performance, but rather used as a chemotactic cue by the highly motile filaments to avoid getting lost at depth in the sediment. Indeed sulfide is a repellant for Beggiatoa...

  14. Efficacy of serum samples stored on filter paper for the detection of antibody to Leptospira spp. by microagglutination test (MAT).

    Science.gov (United States)

    Blanco, R M; Romero, E C

    2012-12-14

    The aim of this study was to investigate the microagglutination test (MAT) results in serum samples dried on filter paper and stored at different temperatures during 1day, 7days, 30days and 1year to determine the stability of sera antibody against leptospires. Serum samples collected onto filter paper for the detection of leptospires antibody was compared with MAT in a study of 300 serum samples from patients with suspected leptospirosis. Among 300 fresh serum samples analyzed by MAT 156 (52%) were positive and 144 (48%) negative. All the negative fresh serum samples were negative when dried on filter paper (specificity 100%). The sensitivity of MAT performed on dried serum samples was 100%. Storage on filter paper at room temperature and at 4°C for 1 and 7days did not affect the MAT titers. For up to 7days, 98.72% of dried serum samples had titers identical to those of the corresponding serum samples, and 1.18% of dried serum samples showed 1 dilution of difference. After a storage period of one month a prozone phenomenon was observed. After a storage period of one year all serum samples were negative. Serum samples collected onto filter paper are a convenient source of antibodies for serological diagnosis and epidemiological surveys. PMID:22960422

  15. Video-supported analysis of Beggiatoa filament growth, breakage, and movement

    DEFF Research Database (Denmark)

    Kamp, Anja; Røy, Hans; Schulz-Vogt, Heide N.

    2008-01-01

    A marine Beggiatoa sp. was cultured in semi-solid agar with opposing oxygen-sulfide gradients. Growth pattern, breakage of filaments for multiplication, and movement directions of Beggiatoa filaments in the transparent agar were investigated by time-lapse video recording. The initial doubling time...

  16. MAT 126 Ash Material - mat126dotcom

    OpenAIRE

    honey

    2015-01-01

    MAT 126 Entire Course For more course tutorials visit www.mat126.com   MAT 126 Week 1 DQ 1 MAT 126 Week 1 Quiz MAT 126 Week 1 Written Assignment (Arithmetic and geometric sequence) MAT 126 Week 2 DQ 1 MAT 126 Week 2 DQ 2 MAT 126 Week 2 Assignment  Is It Fat Free MAT 126 Week 2 Quiz MAT 126 Week 3 DQ 1 MAT 126 Week 3 DQ 2 MAT 126 Week 3 Assignment Quadratic Equations MAT 126 Week 3 Quiz MAT 126 Week 4 DQ 1 MAT 126 Week 4 DQ 2 MAT...

  17. Talking Mats

    DEFF Research Database (Denmark)

    2012-01-01

    Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities.......Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities....

  18. Sulfide induces phosphate release from polyphosphate in cultures of a marine Beggiatoa strain

    OpenAIRE

    Brock, Jörg; Schulz-Vogt, Heide N.

    2010-01-01

    Sulfur bacteria such as Beggiatoa or Thiomargarita have a particularly high capacity for storage because of their large size. In addition to sulfur and nitrate, these bacteria also store phosphorus in the form of polyphosphate. Thiomargarita namibiensis has been shown to release phosphate from internally stored polyphosphate in pulses creating steep peaks of phosphate in the sediment and thereby inducing the precipitation of phosphorus-rich minerals. Large sulfur bacteria populate sediments a...

  19. Structure and function of natural sulphide-oxidizing microbial mats under dynamic input of light and chemical energy.

    Science.gov (United States)

    Klatt, Judith M; Meyer, Steffi; Häusler, Stefan; Macalady, Jennifer L; de Beer, Dirk; Polerecky, Lubos

    2016-04-01

    We studied the interaction between phototrophic and chemolithoautotrophic sulphide-oxidizing microorganisms in natural microbial mats forming in sulphidic streams. The structure of these mats varied between two end-members: one characterized by a layer dominated by large sulphur-oxidizing bacteria (SOB; mostly Beggiatoa-like) on top of a cyanobacterial layer (B/C mats) and the other with an inverted structure (C/B mats). C/B mats formed where the availability of oxygen from the water column was limited (45 μM) and continuously present. Here SOB were independent of the photosynthetic activity of cyanobacteria and outcompeted the cyanobacteria in the uppermost layer of the mat where energy sources for both functional groups were concentrated. Outcompetition of photosynthetic microbes in the presence of light was facilitated by the decoupling of aerobic chemolithotrophy and oxygenic phototrophy. Remarkably, the B/C mats conserved much less energy than the C/B mats, although similar amounts of light and chemical energy were available. Thus ecosystems do not necessarily develop towards optimal energy usage. Our data suggest that, when two independent sources of energy are available, the structure and activity of microbial communities is primarily determined by the continuous rather than the intermittent energy source, even if the time-integrated energy flux of the intermittent energy source is greater. PMID:26405833

  20. MAT FOR LEPTOSPIROSIS DIAGNOSIS

    Directory of Open Access Journals (Sweden)

    Esti Rahardianingtyas.

    2014-06-01

    Full Text Available Leptospirosis is a disease caused by bacterial infection leptospira interrogans.Leptospira bacteria is a spiral bacterium with solid strands with two flagella periplasmik.Septicaemic phase patient samples taken from the blood and cerebrospinal fluid, whereassamples taken at phase immune extracted from urine. The diagnosis of leptospirosis occurdirectly or indirectly. Diagnosis is done by directly isolate and identify the causative agents ofthe agent. Diagnosis is done indirectly by detecting specific antibodies from the patient's body.Gold Standard of the diagnosis of leptospirosis is MAT. Mat made by reacting antibodies toleptospira antigen. Positive results seen with clump formed.Key words: Leptospirosis, Leptospirosis Diagnostic, MAT (Microscopic Agglutination Test Leptospirosis merupakan penyakit yang disebabkan karena infeksi bakteri leptospirainterrogans. Bakteri leptospira merupakan bakteri spiral dengan untaian yang padat dengan duaflagella periplasmik. Sampel pasien pada fase septicaemic diambil dari darah dan cairanserebrospinal, sedangkan sampel yang diambil pada fase immune diambil dari urine. Diagnosisleptospirosis dilakukan secara langsung maupun tidak langsung. Diagnosis secara langsungdilakukan dengan cara mengisolasi agen penyebab dan mengidentifikasi agen tersebut. Diagnosissecara tidak langsung dilakukan dengan cara mendeteksi antibodi spesiflk dari dalam tubuhpasien. Gold Standart dari diagnosis leptospirosis adalah MAT. Mat dilakukan dengan caramereaksikan antibodi dengan antigen leptospira. Hasil positif dilihat dengan terbentuk gumpalanagglutinasiKata kunci: Leptospirosis, Leptospira, Leptospirosis Diagnosis.

  1. MAT 126 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    stylia

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 126 Week 1 DQ 1 (Ash) MAT 126 Week 1 Quiz (Ash) MAT 126 Week 1 Written Assignment (Arithmetic and geometric sequence) (Ash) MAT 126 Week 2 DQ 1 (Ash) MAT 126 Week 2 DQ 2 (Ash) MAT 126 Week 2 Assignment Is It Fat Free (Ash) MAT 126 Week 2 Quiz (Ash) MAT 126 Week 3 DQ 1 (Ash) MAT 126 Week 3 DQ 2 (Ash) MAT 126 Week 3 Assignment Quadratic Equations (Ash) MAT 126 Week 3 Quiz (Ash) MAT 126...

  2. Biogeochemistry of Microbial Mats

    Science.gov (United States)

    DesMarais, David J.; DeVincenizi, D. (Technical Monitor)

    2002-01-01

    The hierarchical organization of microbial ecosystems determines the rates of processes that shape Earth's environment, define the stage upon which major evolutionary events occurred, and create biosignatures in sediments and atmospheres. In cyanobacterial mats, oxygenic photosynthesis provides energy, organic substrates and oxygen to the ecosystem. Incident light changes with depth in the mat, both in intensity and spectral composition, and counteracting gradients of oxygen and sulfide shape the chemical microenvironment. A combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods and to various depths in the mat. Microliters produce hydrogen, small organic acids, nitrogen and sulfur species. Such compounds fuel a flow of energy and electrons in these ecosystems and thus shape interactions between groups of microorganisms. Coordinated observations of population distribution, abundance, and activity for an entire community are making fundamental questions in ecology accessible. These questions address those factors that sustain the remarkable diversity of microorganisms that are now being revealed by molecular techniques. These questions also target the processes that shape the various kinds of biosignatures that we will seek, both in ancient rocks from Earth and Mars, and in atmospheres of distant planets beyond our Solar System.

  3. Two new Beggiatoa species inhabiting marine mangrove sediments in the Caribbean.

    Directory of Open Access Journals (Sweden)

    Maïtena R N Jean

    Full Text Available Beggiatoaceae, giant sulphur-oxidizing bacteria, are well known to occur in cold and temperate waters, as well as hydrothermal vents, where they form dense mats on the floor. However, they have never been described in tropical marine mangroves. Here, we describe two new species of benthic Beggiatoaceae colonizing a marine mangrove adjacent to mangrove roots. We combined phylogenetic and lipid analysis with electron microscopy in order to describe these organisms. Furthermore, oxygen and sulphide measurements in and ex situ were performed in a mesocosm to characterize their environment. Based on this, two new species, Candidatus Maribeggiatoa sp. and Candidatus Isobeggiatoa sp. inhabiting tropical marine mangroves in Guadeloupe were identified. The species identified as Candidatus Maribeggiatoa group suggests that this genus could harbour a third cluster with organisms ranging from 60 to 120 μm in diameter. This is also the first description of an Isobeggiatoa species outside of Arctic and temperate waters. The multiphasic approach also gives information about the environment and indications for the metabolism of these bacteria. Our study shows the widespread occurrence of members of Beggiatoaceae family and provides new insight in their potential role in shallow-water marine sulphide-rich environments such as mangroves.

  4. MAT 221 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    mirat

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 221 Week 1 Assignment 1 Simplifying Expressions (Ash) MAT 221 Week 1 DQ 1 Evaluating Algebraic Expressions (Ash) MAT 221 Week 2 Assignment 2 Inequalities (Ash) MAT 221 Week 2 DQ 1 Formulas (Ash) MAT 221 Week 3 Assignment 3 Two-Variable Inequality (Ash) MAT 221 Week 3 DQ 1 Parallel and Perpendicular (Ash) MAT 221 Week 4 Assignment 4 Financial Polynomials (Ash) MAT 221 Week 4 DQ 1 Initial Investme...

  5. Physiological and Metagenomic Analyses of Microbial Mats Involved in Self-Purification of Mine Waters Contaminated with Heavy Metals

    Science.gov (United States)

    Drewniak, Lukasz; Krawczyk, Pawel S.; Mielnicki, Sebastian; Adamska, Dorota; Sobczak, Adam; Lipinski, Leszek; Burec-Drewniak, Weronika; Sklodowska, Aleksandra

    2016-01-01

    Two microbial mats found inside two old (gold and uranium) mines in Zloty Stok and Kowary located in SW Poland seem to form a natural barrier that traps heavy metals leaking from dewatering systems. We performed complex physiological and metagenomic analyses to determine which microorganisms are the main driving agents responsible for self-purification of the mine waters and identify metabolic processes responsible for the observed features. SEM and energy dispersive X-ray microanalysis showed accumulation of heavy metals on the mat surface, whereas, sorption experiments showed that neither microbial mats were completely saturated with heavy metals present in the mine waters, indicating that they have a large potential to absorb significant quantities of metal. The metagenomic analysis revealed that Methylococcaceae and Methylophilaceae families were the most abundant in both communities, moreover, it strongly suggest that backbones of both mats were formed by filamentous bacteria, such as Leptothrix, Thiothrix, and Beggiatoa. The Kowary bacterial community was enriched with the Helicobacteraceae family, whereas the Zloty Stok community consist mainly of Sphingomonadaceae, Rhodobacteraceae, and Caulobacteraceae families. Functional (culture-based) and metagenome (sequence-based) analyses showed that bacteria involved in immobilization of heavy metals, rather than those engaged in mobilization, were the main driving force within the analyzed communities. In turn, a comparison of functional genes revealed that the biofilm formation and heavy metal resistance (HMR) functions are more desirable in microorganisms engaged in water purification than the ability to utilize heavy metals in the respiratory process (oxidation-reduction). These findings provide insight on the activity of bacteria leading, from biofilm formation to self-purification, of mine waters contaminated with heavy metals. PMID:27559332

  6. Molecular ecology of microbial mats

    NARCIS (Netherlands)

    Bolhuis, H.; Cretoiu, M.S.; Stal, L.J.

    2014-01-01

    Phototrophic microbial mats are ideal model systems for ecological and evolutionary analysis of highly diverse microbial communities. Microbial mats are small-scale, nearly closed, and self-sustaining benthic ecosystems that comprise the major element cycles, trophic levels, and food webs. The steep

  7. Auspicious tatami mat arrangements

    CERN Document Server

    Erickson, Alejandro; Schurch, Mark; Woodcock, Jennifer

    2011-01-01

    An \\emph{auspicious tatami mat arrangement} is a tiling of a rectilinear region with two types of tiles, $1 \\times 2$ tiles (dimers) and $1 \\times 1$ tiles (monomers). The tiles must cover the region and satisfy the constraint that no four corners of the tiles meet; such tilings are called \\emph{tatami tilings}. The main focus of this paper is when the rectilinear region is a rectangle. We provide a structural characterization of rectangular tatami tilings and use it to prove that the tiling is completely determined by the tiles that are on its border. We prove that the number of tatami tilings of an $n \\times n$ square with $n$ monomers is $n2^{n-1}$. We also show that, for fixed-height, the generating function for the number of tatami tilings of a rectangle is a rational function, and outline an algorithm that produces the generating function.

  8. Modeling benthic–pelagic nutrient exchange processes and porewater distributions in a seasonally hypoxic sediment: evidence for massive phosphate release by Beggiatoa?

    Directory of Open Access Journals (Sweden)

    K. Wallmann

    2013-02-01

    Full Text Available This study presents benthic data from 12 samplings from February to December 2010 in a 28 m deep channel in the southwest Baltic Sea. In winter, the distribution of solutes in the porewater was strongly modulated by bioirrigation which efficiently flushed the upper 10 cm of sediment, leading to concentrations which varied little from bottom water values. Solute pumping by bioirrigation fell sharply in the summer as the bottom waters became severely hypoxic (2. At this point the giant sulfide-oxidizing bacteria Beggiatoa was visible on surface sediments. Despite an increase in O2 following mixing of the water column in November, macrofauna remained absent until the end of the sampling. Contrary to expectations, metabolites such as dissolved inorganic carbon, ammonium and hydrogen sulfide did not accumulate in the upper 10 cm during the hypoxic period when bioirrigation was absent, but instead tended toward bottom water values. This was taken as evidence for episodic bubbling of methane gas out of the sediment acting as an abiogenic irrigation process. Porewater–seawater mixing by escaping bubbles provides a pathway for enhanced nutrient release to the bottom water and may exacerbate the feedback with hypoxia. Subsurface dissolved phosphate (TPO4 peaks in excess of 400 μM developed in autumn, resulting in a very large diffusive TPO4 flux to the water column of 0.7 ± 0.2 mmol m−2 d−1. The model was not able to simulate this TPO4 source as release of iron-bound P (Fe–P or organic P. As an alternative hypothesis, the TPO4 peak was reproduced using new kinetic expressions that allow Beggiatoa to take up porewater TPO4 and accumulate an intracellular P pool during periods with oxic bottom waters. TPO4 is then released during hypoxia, as previous published results with sulfide-oxidizing bacteria indicate. The TPO4 added to the porewater over the year by organic P and Fe–P is recycled through Beggiatoa, meaning that no additional source of

  9. Modeling benthic-pelagic nutrient exchange processes and porewater distributions in a seasonally-hypoxic sediment: evidence for massive phosphate release by Beggiatoa?

    Directory of Open Access Journals (Sweden)

    K. Wallmann

    2012-08-01

    Full Text Available This study presents benthic data from 12 samplings from February to December 2010 in a 2 m deep channel in the southwest Baltic Sea. In winter, the distribution of solutes in the porewater was strongly modulated by bioirrigation which efficiently flushed the upper 1 cm of sediment, leading to concentrations which varied little from bottom water values. Solute pumping by bioirrigation fell sharply in summer as the bottom waters became severely hypoxic (2. At this point the giant sulfide-oxidizing bacteria Beggiatoa was visible on surface sediments. Despite an increase in O2following mixing of the water column in November, macrofauna remained absent until the end of the sampling. Contrary to expectations, metabolites such as dissolved inorganic carbon, ammonium and hydrogen sulfide did not accumulate in the porewater during the hypoxic period when bioirrigation was absent, but instead tended toward bottom water values. This was taken as evidence for episodic bubbling of methane gas out of the sediment acting as an abiogenic irrigation process. Escaping bubble may provide a pathway for enhanced nutrient release to the bottom water and exacerbate the feedbacks with hypoxia. Subsurface dissolved phosphate (TPO4 peaks in excess of 400 μM developed in autumn resulting in a very large diffusive TPO4 flux to the water column of 0.7 ± 0.2 mmol m−2 d−1. The model was not able to simulate this TPO4 source as release of iron-bound P (Fe–P or organic P. As an alternative hypothesis, the TPO4 peak was reproduced using new kinetic expressions that allow Beggiatoa to take up porewater TPO4 and accumulate an intracellular P pool during periods with oxic bottom waters. TPO4 is then released during hypoxia, as previous published results with sulfide-oxidizing bacteria indicate. The TPO4 added to the porewater over the year by organic P and Fe–P is recycled though Beggiatoa, meaning that no additional source of TPO4 is needed to explain the TPO4 peak

  10. MAT 222 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    mirat

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 222 Week 1 Solving Proportions (Ash) MAT 222 Week 1 DQ 1 Can't Cancel Terms (Ash) MAT 222 Week 2 DQ 1 One-Variable Compound Inequalities (Ash) MAT 222 Week 2 Two-Variable Inequalities (Ash) MAT 222 Week 3 DQ 1 Simplifying Radicals (Ash) MAT 222 Week 3 Real World Radical Formulas (Ash) MAT 222 Week 4 DQ 1 Solving Quadratic Equations (Ash) MAT 222 Week 4 Real World Quadratic Functions (Ash) ...

  11. Compressibility of electrospun fiber mats

    OpenAIRE

    Choong, Looh Tchuin; Mannarino, Matthew M.; Basu, Sandip; Rutledge, Gregory C.

    2013-01-01

    Compressive properties of electrospun fiber mats are reported for the first time. Mats of bisphenol-A polysulfone (PSU) and of poly(trimethyl hexamethylene terephthalamide) [PA 6(3)T] were electrospun and annealed over a range of temperatures spanning the glass transition temperature of each polymer. The data for applied stress versus mat solidity were found to be well-described by a power law of the form σ[subscript zz] = kE(ϕ[superscript n] − ϕ[n over 0]), where σ[subscript zz] is the appli...

  12. Molecular ecology of microbial mats

    OpenAIRE

    Bolhuis, H; Cretoiu, M.S.; Stal, L.J.

    2014-01-01

    Phototrophic microbial mats are ideal model systems for ecological and evolutionary analysis of highly diverse microbial communities. Microbial mats are small-scale, nearly closed, and self-sustaining benthic ecosystems that comprise the major element cycles, trophic levels, and food webs. The steep and fluctuating physicochemical microgradients, that are the result of the ever changing environmental conditions and of the microorganisms' own activities, give rise to a plethora of potential ni...

  13. Sparse Coding for Alpha Matting

    OpenAIRE

    Johnson, Jubin; Varnousfaderani, Ehsan Shahrian; Cholakkal, Hisham; Rajan, Deepu

    2016-01-01

    Existing color sampling based alpha matting methods use the compositing equation to estimate alpha at a pixel from pairs of foreground (F) and background (B) samples. The quality of the matte depends on the selected (F,B) pairs. In this paper, the matting problem is reinterpreted as a sparse coding of pixel features, wherein the sum of the codes gives the estimate of the alpha matte from a set of unpaired F and B samples. A non-parametric probabilistic segmentation provides a certainty measur...

  14. Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs

    Energy Technology Data Exchange (ETDEWEB)

    Beam, Jake; Bernstein, Hans C.; Jay, Z.; Kozubal, Mark; Jennings, Ryan; Tringe, Susannah G.; Inskeep, William P.

    2016-02-15

    Iron oxide microbial mats are ubiquitous geobiological features on Earth and occur in extant acidic hot springs of Yellowstone National Park (YNP), WY, USA, and form as a result of microbial processes. The relative contribution of different organisms to the development of these mat ecosystems is of specific interest. We hypothesized that chemolithoautotrophic organisms contribute to the early development and production of Fe(III)-oxide mats, which could support later-colonizing heterotrophic microorganisms. Sterile glass slides were incubated in the outflow channels of two acidic geothermal springs in YNP, and spatiotemporal changes in Fe(III)-oxide accretion and abundance of relevant community members were measured. Lithoautotrophic Hydrogenobaculum spp. were first colonizers and the most abundant taxa identified during early successional stages (7 – 40 days). Populations of M. yellowstonensis colonized after ~ 7 days, corresponding to visible Fe(III)-oxide accretion. Heterotrophic archaea colonized after 30 days, and emerge as the dominant functional guild in mature iron oxide mats (1 – 2 cm thick) that form after 70 – 120 days. First-order rate constants of iron oxide accretion ranged from 0.05 – 0.046 day-1, and reflected the absolute amount of iron accreted. Micro- and macroscale microterracettes were identified during iron oxide mat development, and suggest that the mass transfer of oxygen limits microbial growth. This was also demonstrated using microelectrode measurements of oxygen as a function of mat depth, which showed steep gradients in oxygen from the aqueous mat interface to ~ 1 mm. The formation and succession of amorphous Fe(III)-oxide mat communities follows a predictable pattern of distinct stages and growth. The successional stages and microbial signatures observed in these extant Fe(III)-oxide mat communities may be relevant to other past or present Fe(III)-oxide mineralizing systems.

  15. Permeability of Electrospun Superhydrophobic Nanofiber Mats

    Directory of Open Access Journals (Sweden)

    Sarfaraz U. Patel

    2012-01-01

    Full Text Available This paper discusses the fabrication and characterization of electrospun nanofiber mats made up of poly(4-methyl-1-pentene polymer. The polymer was electrospun in different weight concentrations. The mats were characterized by their basis weight, fiber diameter distribution, contact angles, contact angle hysteresis, and air permeability. All of the electrospun nonwoven fiber mats had water contact angles greater than 150 degrees making them superhydrophobic. The permeabilities of the mats were empirically fitted to the mat basis weight by a linear relation. The experimentally measured air permeabilities were significantly larger than the permeabilities predicted by the Kuwabara model for fibrous media.

  16. Is the microagglutination test (MAT) good for predicting the infecting serogroup for leptospirosis in Brazil?

    Science.gov (United States)

    Blanco, Roberta Morozetti; dos Santos, Luis Fernando; Galloway, Renee Lynn; Romero, Eliete Caló

    2016-02-01

    Leptospirosis is a zoonotic infection caused by pathogenic members of the genus Leptospira spp. Knowledge of the prevalent serovars and their maintenance hosts is essential to understand the disease. The aim of this study was to evaluate the ability of serology by the microscopic agglutination test (MAT) to predict the serogroups compared with results of identification of leptospires in São Paulo, Brazil. MAT correctly assigned the serogroup of the infecting isolate in 49/52 cases (94.23%). The serogroup Icterohaemorrhagiae was the predominant serogroup (88.46%). This study showed the usefulness of the MAT to correctly identify the infecting serogroup with a good overall agreement between the serologically-identified infecting serogroup and by identification of the isolate and can be used in epidemiological surveys in São Paulo. However, it should be complemented by the identification of Leptospira isolates. PMID:26851592

  17. Analysis of lipophilic pigments from a phototrophic microbial mat community by high performance liquid chromatography

    Science.gov (United States)

    Palmisano, A. C.; Cronin, S. E.; Des Marais, D. J.

    1988-01-01

    As assay for lipophilic pigments in phototrophic microbial mat communities using reverse phase-high performance liquid chromatography was developed which allows the separation of 15 carotenoids and chloropigments in a single 30 min program. Lipophilic pigments in a laminated mat from a commercial salina near Laguna Guerrero Negro, Baja California Sur, Mexico reflected their source organisms. Myxoxanthophyll, echinenone, canthaxanthin, and zeaxanthin were derived from cyanobacteria; chlorophyll c, and fucoxanthin from diatoms; chlorophyll a from cyanobacteria and diatoms; bacteriochlorophylls a and c, bacteriophaeophytin a, and gamma-carotene from Chloroflexus spp.; and beta-carotene from a variety of phototrophs. Sensitivity of detection was 0.6-6.1 ng for carotenoids and 1.7-12 ng for most chloropigments. This assay represents a significant improvement over previous analyses of lipophilic pigments in microbial mats and promises to have a wider application to other types of phototrophic communities.

  18. Archaean metabolic evolution of microbial mats

    OpenAIRE

    Nisbet, E. G.; Fowler, C. M. R.

    1999-01-01

    Microbial mats of coexisting bacteria and archaea date back to the early Archaean: many of the major steps in early evolution probably took place within them. The earliest mats may have formed as biofilms of cooperative chemolithotrophs in hyperthermophile settings, with microbial exploitation of diversifying niches. Anoxygenic photosynthesis using bacteriochlorophyll could have allowed mats, including green gliding bacteria, to colonize anaerobic shallow-water mesothermophile habitats. Explo...

  19. MatLab Script and Functional Programming

    Science.gov (United States)

    Shaykhian, Gholam Ali

    2007-01-01

    MatLab Script and Functional Programming: MatLab is one of the most widely used very high level programming languages for scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. The MatLab seminar covers the functional and script programming aspect of MatLab language. Specific expectations are: a) Recognize MatLab commands, script and function. b) Create, and run a MatLab function. c) Read, recognize, and describe MatLab syntax. d) Recognize decisions, loops and matrix operators. e) Evaluate scope among multiple files, and multiple functions within a file. f) Declare, define and use scalar variables, vectors and matrices.

  20. Bentonite mat demonstration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Serrato, M.G.

    1994-12-30

    The Bentonite Mat Demonstration was developed to provide the Environmental Restoration Department with field performance characteristics and engineering data for an alternative closure cover system configuration. The demonstration was initiated in response to regulatory concerns regarding the use of an alternative cover system for future design configurations. These design considerations are in lieu of the US Environmental Protection Agency (EPA) Recommended Design for Closure Cover Systems and specifically a single compacted kaolin clay layer with a hydraulic conductivity of 1 {times} 10{sup {minus}7} cm/sec. This alternative configuration is a composite geosynthetic material hydraulic barrier consisting from bottom to top: 2 ft compacted sandy clay layer (typical local Savannah River Site soil type) that is covered by a bentonite mat--geosynthetic clay liner (GCL) and is overlaid by a 40 mil High Density Polyethylene (HDPE) geomembrane--flexible membrane liner. This effort was undertaken to obtain and document the necessary field performance/engineering data for future designs and meet regulatory technical requirements for an alternative cover system configuration. The composite geosynthetic materials hydraulic barrier is the recommended alternative cover system configuration for containment of hazardous and low level radiological waste layers that have a high potential of subsidence to be used at the Savannah River Site (SRS). This alternative configuration mitigates subsidence effects in providing a flexible, lightweight cover system to maintain the integrity of the closure. The composite geosynthetic materials hydraulic barrier is recommended for the Sanitary Landfill and Low Level Radiological Waste Disposal Facility (LLRWDF) Closures.

  1. Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs

    Directory of Open Access Journals (Sweden)

    Jacob P. Beam

    2016-02-01

    Full Text Available Biomineralized ferric oxide microbial mats are ubiquitous features on Earth, are common in hot springs of Yellowstone National Park (YNP, WY, USA, and form due to direct interaction between microbial and physicochemical processes. The overall goal of this study was to determine the contribution of different community members to the assembly and succession of acidic high-temperature Fe(III-oxide mat ecosystems. Spatial and temporal changes in Fe(III-oxide accretion and the abundance of relevant community members were monitored over 70 days using sterile glass microscope slides incubated in the outflow channels of two acidic geothermal springs (pH = 3 - 3.5; temperature = 68 - 75 °C in YNP. Hydrogenobaculum spp. were the most abundant taxon identified during early successional stages (4 - 40 d, and have been shown to oxidize arsenite, sulfide, and hydrogen coupled to oxygen reduction. Iron-oxidizing populations of Metallosphaera yellowstonensis were detected within 4 d, and reached steady-state levels within 14 - 30 d, corresponding to visible Fe(III-oxide accretion. Heterotrophic archaea colonized near 30 d, and emerged as the dominant functional guild after 70 d and in mature Fe(III-oxide mats (1 - 2 cm thick. First-order rate constants of Fe(III-oxide accretion ranged from 0.046 - 0.05 d-1, and in situ microelectrode measurements showed that the oxidation of Fe(II is limited by the diffusion of O2 into the Fe(III-oxide mat. The formation of microterracettes also implicated O2 as a major variable controlling microbial growth and subsequent mat morphology. The assembly and succession of Fe(III-oxide mat communities follows a repeatable pattern of colonization by lithoautotrophic organisms, and the subsequent growth of diverse organoheterotrophs. The unique geochemical signatures and micromorphology of extant biomineralized Fe(III-oxide mats are useful for understanding other Fe(II-oxidizing systems.

  2. Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs.

    Science.gov (United States)

    Beam, Jacob P; Bernstein, Hans C; Jay, Zackary J; Kozubal, Mark A; Jennings, Ryan deM; Tringe, Susannah G; Inskeep, William P

    2016-01-01

    Biomineralized ferric oxide microbial mats are ubiquitous features on Earth, are common in hot springs of Yellowstone National Park (YNP, WY, USA), and form due to direct interaction between microbial and physicochemical processes. The overall goal of this study was to determine the contribution of different community members to the assembly and succession of acidic high-temperature Fe(III)-oxide mat ecosystems. Spatial and temporal changes in Fe(III)-oxide accretion and the abundance of relevant community members were monitored over 70 days using sterile glass microscope slides incubated in the outflow channels of two acidic geothermal springs (pH = 3-3.5; temperature = 68-75°C) in YNP. Hydrogenobaculum spp. were the most abundant taxon identified during early successional stages (4-40 days), and have been shown to oxidize arsenite, sulfide, and hydrogen coupled to oxygen reduction. Iron-oxidizing populations of Metallosphaera yellowstonensis were detected within 4 days, and reached steady-state levels within 14-30 days, corresponding to visible Fe(III)-oxide accretion. Heterotrophic archaea colonized near 30 days, and emerged as the dominant functional guild after 70 days and in mature Fe(III)-oxide mats (1-2 cm thick). First-order rate constants of Fe(III)-oxide accretion ranged from 0.046 to 0.05 day(-1), and in situ microelectrode measurements showed that the oxidation of Fe(II) is limited by the diffusion of O2 into the Fe(III)-oxide mat. The formation of microterracettes also implicated O2 as a major variable controlling microbial growth and subsequent mat morphology. The assembly and succession of Fe(III)-oxide mat communities follows a repeatable pattern of colonization by lithoautotrophic organisms, and the subsequent growth of diverse organoheterotrophs. The unique geochemical signatures and micromorphology of extant biomineralized Fe(III)-oxide mats are also useful for understanding other Fe(II)-oxidizing systems. PMID:26913020

  3. Effects of mat characteristics on plantar pressure patterns and perceived mat properties during landing in gymnastics.

    Science.gov (United States)

    Pérez-Soriano, Pedro; Llana-Belloch, Salvador; Morey-Klapsing, Gaspar; Perez-Turpin, Jose Antonio; Cortell-Tormo, Juan Manuel; van den Tillaar, Roland

    2010-11-01

    Shock absorption and stability during landings is provided by both, gymnast ability and mat properties. The aims of this study were to determine the influence of different mat constructions on their energy absorption and stability capabilities, and to analyse how these properties affect gymnast's plantar pressures as well as subjective mat perception during landing. Six mats were tested using a standard mechanical drop test. In addition, plantar pressures and subjective perception during landing were obtained from 15 expert gymnasts. The different mats influenced plantar pressures and gymnasts' subjective perception during landing of gymnasts. Significant correlations between plantar pressures at the medial metatarsal and lateral metatarsal zones of the gymnasts' feet with the different shock absorption characteristics of the mats were found. However, subjective perception tests were not able to discriminate mat functionality between the six mats as no significant correlations between the mechanical mat properties with the subjective perception of these properties were found. This study demonstrated that plantar pressures are a useful tool for discriminating different landing mats. Using similar approaches, ideally including kinematics as well, could help us in our understanding about the influences of different mats upon gymnast-mat interaction. PMID:21309299

  4. Nonwoven glass fiber mat reinforces polyurethane adhesive

    Science.gov (United States)

    Roseland, L. M.

    1967-01-01

    Nonwoven glass fiber mat reinforces the adhesive properties of a polyurethane adhesive that fastens hardware to exterior surfaces of aluminum tanks. The mat is embedded in the uncured adhesive. It ensures good control of the bond line and increases the peel strength.

  5. Investigation of VEGGIE Root Mat

    Science.gov (United States)

    Subbiah, Arun M.

    2013-01-01

    VEGGIE is a plant growth facility that utilizes the phenomenon of capillary action as its primary watering system. A cloth made of Meta Aramid fiber, known as Nomex is used to wick water up from a reservoir to the bottom of the plants roots. This root mat system is intended to be low maintenance with no moving parts and requires minimal crew interface time. Unfortunately, the water wicking rates are inconsistent throughout the plant life cycle, thus causing plants to die. Over-wicking of water occurs toward the beginning of the cycle, while under-wicking occurs toward the middle. This inconsistency of wicking has become a major issue, drastically inhibiting plant growth. The primary objective is to determine the root cause of the inconsistent wicking through experimental testing. Suspect causes for the capillary water column to break include: a vacuum effect due to a negative pressure gradient in the water reservoir, contamination of material due to minerals in water and back wash from plant fertilizer, induced air bubbles while using syringe refill method, and material limitations of Nomex's ability to absorb and retain water. Experimental testing will be conducted to systematically determine the cause of under and over-wicking. Pressure gages will be used to determine pressure drop during the course of the plant life cycle and during the water refill process. A debubbler device will be connected to a root mat in order to equalize pressure inside the reservoir. Moisture and evaporation tests will simultaneously be implemented to observe moisture content and wicking rates over the course of a plant cycle. Water retention tests will be performed using strips of Nomex to determine materials wicking rates, porosity, and absorptivity. Through these experimental tests, we will have a better understanding of material properties of Nomex, as well as determine the root cause of water column breakage. With consistent test results, a forward plan can be achieved to resolve

  6. Flat laminated microbial mat communities

    Science.gov (United States)

    Franks, Jonathan; Stolz, John F.

    2009-10-01

    Flat laminated microbial mats are complex microbial ecosystems that inhabit a wide range of environments (e.g., caves, iron springs, thermal springs and pools, salt marshes, hypersaline ponds and lagoons, methane and petroleum seeps, sea mounts, deep sea vents, arctic dry valleys). Their community structure is defined by physical (e.g., light quantity and quality, temperature, density and pressure) and chemical (e.g., oxygen, oxidation/reduction potential, salinity, pH, available electron acceptors and donors, chemical species) parameters as well as species interactions. The main primary producers may be photoautotrophs (e.g., cyanobacteria, purple phototrophs, green phototrophs) or chemolithoautophs (e.g., colorless sulfur oxidizing bacteria). Anaerobic phototrophy may predominate in organic rich environments that support high rates of respiration. These communities are dynamic systems exhibiting both spatial and temporal heterogeneity. They are characterized by steep gradients with microenvironments on the submillimeter scale. Diel oscillations in the physical-chemical profile (e.g., oxygen, hydrogen sulfide, pH) and species distribution are typical for phototroph-dominated communities. Flat laminated microbial mats are often sites of robust biogeochemical cycling. In addition to well-established modes of metabolism for phototrophy (oxygenic and non-oxygenic), respiration (both aerobic and anaerobic), and fermentation, novel energetic pathways have been discovered (e.g., nitrate reduction couple to the oxidation of ammonia, sulfur, or arsenite). The application of culture-independent techniques (e.g., 16S rRNA clonal libraries, metagenomics), continue to expand our understanding of species composition and metabolic functions of these complex ecosystems.

  7. Efeitos de diferentes níveis de matéria orgânica no solo e de inóculo sobre a interação planta-Meloidogyne spp. e a produção massal de Pasteuria penetrans Effects of cow manure levels in the soil and inoculum concentration on the plant-Meloidogyne spp. interaction and on the mass production of Pasteuria penetrans

    Directory of Open Access Journals (Sweden)

    Fábio Ramos Alves

    2007-12-01

    Full Text Available Foram estudados os efeitos de quatro proporções de esterco de curral no solo, 0, 20, 33 e 50% (V:V, e três níveis de inóculo de Meloidogyne spp. (3.000, 6.000 e 9.000 J2 por planta na concentração de fenóis em raízes de tomateiro, no desenvolvimento das fêmeas, nas células gigantes induzidas por esses patógenos e na infecção e reprodução de Pasteuria penetrans. O experimento foi conduzido em casa-de-vegetação, em delineamento inteiramente ao acaso com doze repetições, sendo avaliado 50 dias após a inoculação das plantas. O tamanho médio das fêmeas do nematóide foi maior quando as plantas foram inoculadas com 3.000 J2. Maior percentual de fêmeas infectadas por P. penetrans foi observado quando não se utilizou esterco no substrato ou quando as plantas foram inoculadas com 3.000 J2. As plantas inoculadas com 9.000 J2 e cultivadas no substrato com 20% de esterco foram as que produziram mais endósporos. A concentração de fenóis nas raízes aumentou à medida que se acrescentou esterco de curral ao substrato. As células gigantes de plantas cultivadas no substrato com 33 e 50% de esterco apresentaram menores número, tamanho e quantidade de núcleos. O aumento da proporção de esterco de curral ao substrato causou aumento nas concentrações de fenóis nas raízes, fato que foi deletério às células gigantes, prejudicial ao desenvolvimento do nematóide e à reprodução de P. penetrans.The effects of four different proportions of cow manure, 0, 20, 33 and 50% (V:V and three Meloidogyne spp. inoculum levels (3,000; 6,000 and 9,000 J2 per plant on the phenol concentration in the tomato roots, in the nematode female development, the giant cells induced by the nematode and on the reproduction of Pasteuria penetrans were investigated. The experiment was carried out in greenhouse, in a completely randomized design with twelve replicates, and evaluated 50 days after inoculation. The size of nematode females was higher when

  8. Expression, purification and preliminary structural analysis of Escherichia coli MatP in complex with the matS DNA site

    International Nuclear Information System (INIS)

    MatP is a small DNA-binding protein of about 18 kDa. In order to understand the DNA-compaction mechanism of MatP at an atomic level, the structures of apo MatP and of the nucleoprotein complex MatP–matS have been studied. The Escherichia coli chromosome is organized into four macrodomains which are found in the replication-origin region (Ori), at the terminus (Ter) and on both its sides (Right and Left). The localization of the macrodomains is subject to programmed changes during the cell cycle. The compaction of the 800 kb Ter macrodomain relies on the binding of the MatP protein to a 13 bp matS motif repeated 23 times. MatP is a small DNA-binding protein of about 18 kDa that shares homology in its C-terminal region with the ribbon–helix–helix (RHH) motifs present in regulatory DNA-binding proteins such as CopG. In order to understand the DNA-compaction mechanism of MatP at an atomic level, it was decided to study the structure of apo MatP and of the nucleoprotein complex MatP–matS by both X-ray diffraction and SAXS analysis. It was demonstrated that MatP forms dimers that bind a single matS motif. Complete native X-ray data sets were collected and phasing of the diffraction data is under way

  9. Macroalgal mats and species abundance: a field experiment

    Science.gov (United States)

    Hull, S. C.

    1987-11-01

    A field experiment was carried out whereby the density of macroalgae ( Enteromorpha spp.) was manipulated and the resultant changes in sediment infaunal density were monitored. Four densities of Enteromorpha spp. were used: 0,0·3, 1, and 3 kg FW m -2, corresponding to control, low-, medium-, and high-density plots. The experiment ran from May to October 1985 and was sampled on three occasions. By July, the density of Corophium volutator was reduced at all weed levels when compared to control plots, whereas densities of Hydrobia ulvae, Macoma balthica, Nereis diversicolor, and Capitella capitata, all increased. Samples taken in October when the weed mats were buried in the sediment showed fewer differences than in July. Macoma, Nereis, and Capitella were still significantly more abundant at medium and high weed densities. Corophium showed no significant treatment effect. There was, however, a highly significant difference in population size structure for Corophium. Measurements of sediment redox potential and silt content under medium- and high-density plots revealed rapid anoxia with a significant increase in siltation.

  10. Composição químico-bromatológica e degradabilidade In Situ da matéria seca, proteína bruta e fibra em detergente neutro da casca do fruto de três variedades de maracujá (Passiflora spp Chemical composition and In situ degradability of dry matter, crude protein and neutral detergent fiber of three varieties passion fruit (Passiflora spp shelves

    Directory of Open Access Journals (Sweden)

    Cláudio Villela Vieira

    1999-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a composição químico-bromatológica e as degradabilidades potenciais e efetivas da matéria seca (MS, proteína bruta (PB e fibra em detergente neutro (FDN do resíduo (casca das variedades de maracujá amarela (Passiflora edulis f. Flavicarpa Degener, roxa (Passiflora edulis Sims e doce (Passiflora alata e da mistura das variedades amarela e roxa. Calcularam-se, também, o consumo de MS e as concentrações de amônia, ácidos graxos voláteis e pH no líquido ruminal e a taxa de passagem das fases líquida e sólida da digesta no rúmen de bovinos. Os resíduos (casca in natura apresentaram grande quantidade de água, enquanto a variedade roxa apresentou o maior teor de matéria seca (17,01% e o amarelo, o menor (10,78%. O teor de proteína bruta variou de 9,82% na MS, para a variedade amarela, a 7,53%, para a doce. O teor de fósforo foi 0,13% na MS para a variedade doce, chegando a 0,09, para a roxo, e 0,08%, para a amarelo. Os teores de cálcio, FDN e FDA não diferiram entre as variedades. Às 48 horas de incubação no rúmen, a degradabilidade atingiu ponto máximo para o teor de MS, PB e FDN. Houve interação de tempo e variedade na degradabilidade de MS, PB e FDN. As degradabilidades de PB e FDN foram influenciadas pelas variedades. A DE da FDN foi maior para a mistura (45,85% e menor para a doce (34,61%. O consumo médio de MS foi de 16,90 kg/animal, equivalente a 3,27% do peso vivo ou 156,11 g/kg0,75, quando se utilizou farelo de casca (resíduo com 90% de MS. As concentrações de ácidos graxos voláteis mantiveram-se na faixa de 7,76 a 10,87 mmoles/100 mL. O pH do líquido ruminal variou de 6,03 a 6,75 e o N-amoniacal, de 4,93 a 9,86 mg/100 mL.Chemical composition and the potential and effective degradabilities of dry matter (DM, crude protein (CP and neutral detergent fiber (NDF of passion fruit residue (shelves were studied in the varieties yellow (Passiflora edulis f. Flavicarpa Degener

  11. Microstructuring of electrospun mats employing femtosecond laser

    Directory of Open Access Journals (Sweden)

    Erika Adomavičiūtė

    2015-03-01

    Full Text Available Electrospun mats from nano/micro-fibers with control porosity and pore shape may be ideal candidate for tissue engineering scaffolds. In this study three type of poly(vinyl alcohol (PVA mats of 48-65 µm thickness with different nano/micro-fibers diameters mostly of 100-200 nm were deposited by electrospinning process. Controlled density porosity in the electrospun mats was introduced by Yb:KGW femtosecond laser micromachining system. The influence of electrospun mat micro structure, the distance between the adjacent laser ablation points, the number of femtosecond laser pulses on quality and structure of laser irradiated holes were investigated. It was demonstrated that the quality of irradiated holes depend on structure of electrospun mats (diameter of nano/micro-fibers, thickness of mats and femtosecond laser processing parameters. Varying the distance between points and number of applied femtosecond laser pulses it is possible to fabricate electrospun mats with pores of 22-36 μm diameter.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.10249

  12. Interactions between macro-algal mats and invertebrates in the Ythan estuary, Aberdeenshire, Scotland

    Science.gov (United States)

    Raffaelli, D.

    2000-07-01

    Blooms of opportunistic green macro-algae are a common feature of coastal areas and their effects on mudflat invertebrates can be dramatic. On the Ythan estuary, Aberdeenshire, Scotland, we have carried out a number of manipulative field experiments designed to evaluate the effects on invertebrates of different species of macro-algae with contrasting ecologies, and the effects of invertebrates on the development of the blooms. Macro-algal mats were found to have dramatic nega- tive effects on the density of the amphipod Corophium volutator, with higher algal biomasses having greater impact. The mechanism for this interaction seems to be interference by the algal filaments with the feeding behaviour of the amphipod. In contrast, the polychaete Capitella spp. increases in abundance under macro-algal mats due to enrichment of the sediment with organic material. These two interactions are seen at all scales, in areas of less than 1 m2 to the scale of the entire estuary, irrespective of the species composition of the macro- algal mats. Bioturbation by Corophium and grazing by the snail Hydrobia ulvae had little effect on macro-algal biomass, but there were less algae when the polychaete Nereis diversicolor was present. The most significant interaction in this system is the pronounced negative impact of algal mats on the abundance of Corophium, probably the most important invertebrate species in the diets of the estuary's shorebirds, fish and epibenthic crustaceans.

  13. Leptospira spp. and Toxoplasma gondii antibodies in vampire bats (Desmodus rotundus in Botucatu region, SP, Brazil

    Directory of Open Access Journals (Sweden)

    CB Zetun

    2009-01-01

    Full Text Available The destruction of natural ecosystems has caused several problems to humans and other animals; herein we investigate the close relationship among vampire bats, humans and domestic animals. Toxoplasma gondii and Leptospira spp. infections are two worldwide zoonoses that provoke serious damage to animals. To determine the prevalence of bats seropositive for toxoplasmosis and leptospirosis in the Botucatu region, 204 serum samples of vampire bats (Desmodus rotundus were tested for T. gondii antibodies by modified agglutination test (MAT-t and for Leptospira spp. by microscopic agglutination test (MAT-l. No animal was tested positive for T. gondii while leptospiral positivity was 7.8% for Pyrogenes, Shermani and Javanica serovars, with titers varying from 100 to 1,600. Thus, it was verified that D. rotundus does not play a relevant role in toxoplasmosis epidemiology. However, these bats can be important in the maintenance of Leptospira spp. in the environment.

  14. Design of reactor building foundation mat system

    International Nuclear Information System (INIS)

    The design of the reactor building foundation mat system represents a great challenge to industry, since the design codes are not written specifically for such large and complicated interfacing configurations. The experimental data are also not available for such mats. It relies heavily upon the designer to decide the appropriate analysis techniques and code applications. The large number of loading combinations in design and the complexity of detailing and construction demonstrate the difficulty of the task. A case study of a BWR 6, Mark III containment vessel reactor building foundation mat system is presented here to describe a complete design. Code jurisdictional boundaries for each component are attempted. The design of the mat has to comply with all the loading combinations required by the regulatory agencies. However, this results in a very large number of combinations to be considered. By inspection, the large number of loading combinations is reduced to a smaller number of controlling combinations, which is analyzed using computer programs. A finite elements model is used for analysis. The soil is represented as elastic springs at the nodes. Using a process of trial and error, the springs that produce tensile stresses are eliminated from subsequent analysis, and only compression springs are retained. This process should give a true picture of the stress conditionn under the mat, and also the stresses within the mat. An acceptance is discussed for the residual local tension forces. (orig./HP)

  15. Contributions of ectomycorrhizal fungal mats to forest soil respiration

    OpenAIRE

    Phillips, C. L.; L. A. Kluber; Martin, J. P.; B. A. Caldwell; B. J. Bond

    2012-01-01

    Distinct aggregations of fungal hyphae and rhizomorphs, or "mats", formed by some genera of ectomycorrhizal (EcM) fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in western Oregon to investigate whether there was higher respiration from mats, and to estimate mat contributions to total soil respiration. We found that are...

  16. Carbon and Oxygen Budgets of Subtidal and Intertidal Cyanobacterial Mats

    Science.gov (United States)

    DesMarais, David J.; Discipulo, Mykell; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Intertidal cyanobacterial mats (Lyngbya-dominated) are contrasted with mats (Microcoleus-dominated) that grow in subtidal (0.7m water depth) hypersaline (90-110 permil) environments. In benthic chamber experiments conducted in Oct., 1999, mats exhibited greater net uptake of dissolved inorganic carbon (DIC) from overlying water during the daylight period than Microcoleus mats (e.g., 200 vs 120 mmol C/m. at 26 deg C, respectively). Net DIC release at night was similar for both mats (approx. 80 mmol C/m). Daytime net O2 release by Lyngby mats exceeded that by Microcoleus mats (150 vs 100 mmol O2/m), and O2 uptake at night was comparable for both mats (60-80 mmol O2/m). Nonphotosynthetic populations are more prominent within the subtidal versus intertidal mats, and accordingly exhibited greater internal 02 uptake and DIC production during the day. Over 24 hours, Lyngby-dominated mats exhibited greater net uptake of DIC than subtidal Microcoleus mats, consistent with these intertidal mats being "pioneer" communities that constantly recover from periodic physical disruption in energetic environments. The Microcoleus-dominated mats achieve steady-state mat thicknesses by balancing primary production against diagenetic decomposition of cellular and extracellular organic constituents.

  17. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    2016-01-01

    A class of spatial point process models that combine short range repulsion with medium range clustering is introduced. The model is motivated by patterns of centres of non-overlapping spherical cells in biological tissue which tend to have a clustering behaviour. Such a combination of clustering...... and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae for the intensity...... and second-order characteristics are established using the conditional Poisson assumption. These formulae include more complicated integrals for which approximations are suggested to simplify calculations. An example from pathology illustrates the applicability of the models....

  18. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    A new class of spatial point process models that combines short range repulsion with medium range clustering is introduced. The model is motivated by patterns of centres of non-overlapping spherical cells in biological tissue which tend to have a clustering behaviour. Such a combination...... of clustering and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae...... for the intensity and second-order characteristics are established using the conditional Poisson assumption. These formulae include more complicated integrals for which approximations are suggested to simplify calculations. An example from pathology illustrates the applicability of the models....

  19. Nitrogen cycle in microbial mats: completely unknown?

    Science.gov (United States)

    Coban, O.; Bebout, B.

    2015-12-01

    Microbial mats are thought to have originated around 3.7 billion years ago, most likely in the areas around submarine hydrothermal vents, which supplied a source of energy in the form of reduced chemical species from the Earth's interior. Active hydrothermal vents are also believed to exist on Jupiter's moon Europa, Saturn's moon Enceladus, and on Mars, earlier in that planet's history. Microbial mats have been an important force in the maintenance of Earth's ecosystems and the first photosynthesis was also originated there. Microbial mats are believed to exhibit most, if not all, biogeochemical processes that exist in aquatic ecosystems, due to the presence of different physiological groups of microorganisms therein. While most microbially mediated biogeochemical transformations have been shown to occur within microbial mats, the nitrogen cycle in the microbial mats has received very little study in spite of the fact that nitrogen usually limits growth in marine environments. We will present the first results in the determination of a complete nitrogen budget for a photosynthetic microbial mat. Both in situ sources and sinks of nitrogen in photosynthetic microbial mats are being measured using stable isotope techniques. Our work has a particular focus on recently described, but poorly understood, processes, e.g., anammox and dissimilatory nitrate reduction, and an emphasis on understanding the role that nitrogen cycling may play in generating biogenic nitrogen isotopic signatures and biomarker molecules. Measurements of environmental controls on nitrogen cycling should offer insight into the nature of co-evolution of these microbial communities and their planets of origin. Identifying the spatial (microscale) as well as temporal (diel and seasonal) distribution of nitrogen transformations, e.g., rates of nitrification and denitrification, within mats, particularly with respect to the distribution of photosynthetically-produced oxygen, is anticipated. The results

  20. Phylogeny of Korean Opuntia spp. based on multiple DNA regions

    OpenAIRE

    Srikanth, Krishnamoorthy; WHANG, SUNG SOO

    2015-01-01

    Although Opuntia species are of high agronomic value in Korea, the taxonomic position of Korean Opuntia species has never been investigated. The taxonomic position of Korean Opuntia spp. Within the tribe Opuntieae was examined based on DNA sequence analysis of matK, trnL-F, atpB-rbcl, and ITS regions. The total amplified sequence length was 2977 bp; only 18 parsimonious informative sites were present, even though they belonged to different species. A phylogenetic tree using both the maximum l...

  1. Emerging pathogens: Aeromonas spp.

    Science.gov (United States)

    Merino, S; Rubires, X; Knochel, S; Tomas, J M

    1995-12-01

    Aeromonas spp. are Gram-negative rods of the family Vibrionaceae. They are normal water inhabitants and are part of the regular flora of poiquilotherm and homeotherm animals. They can be isolated from many foodstuffs (green vegetables, raw milk, ice cream, meat and seafood). Mesophilic Aeromonas spp. have been classified following the AeroKey II system (Altwegg et al., 1990; Carnahan et al., 1991). The major human diseases caused by Aeromonas spp. can be classified in two major groups: septicemia (mainly by strains of A. veronii subsp. sobria and A. hydrophila), and gastroenteritis (any mesophilic Aeromonas spp. but principally A. hydrophila and A. veronii). Most epidemiological studies have shown Aeromonas spp. in stools to be more often associated with diarrhea than with the carrier state; an association with the consumption of untreated water was also conspicuous. Acute self-limited diarrhea is more frequent in young children, in older patients chronic enterocolitis may also be observed. Fever, vomiting, and fecal leukocytes or erythrocytes (colitis) may be present (Janda, 1991). The main putative virulence factors are: exotoxins, endotoxin (LPS), presence of S-layers, fimbriae or adhesins and the capacity to form capsules. PMID:8750664

  2. HiRadMat: materials under scrutiny

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    CERN's new facility, HiRadMat (High Radiation to Materials), which is designed to test materials for the world's future particle accelerators, should be operational and welcoming its first experiments by the end of the year.   The HiRadMat facility, located in the TNC tunnel. The materials used in the LHC and its experiments are exposed to very high-energy particles. The LHC machine experts obviously didn't wait for the first collisions in the world's most powerful accelerator to put the materials through their paces - the equipment was validated following a series of stringent tests. And these tests will get even tougher now, with the arrival of HiRadMat. The tunnel that formerly housed the West Area Neutrino Facility (WANF) has been completely revamped to make way for CERN's latest facility, HiRadMat. Supported by the Radioprotection service, a team from the Engineering (EN) Department handled the dismantling operations from October 2009 to December 2010. "We could only work on disman...

  3. Thermodynamics and phase transformations the selected works of Mats Hillert

    CERN Document Server

    Lilensten, Jean

    2006-01-01

    This book is a compendium of Mat Hillert's publications. Mat Hillert is a world specialist in metal alloy at the origin of a universal computing code used to calculate the diagrams of phase. This work is in English.

  4. Method for production of carbon nanofiber mat or carbon paper

    Science.gov (United States)

    Naskar, Amit K.

    2015-08-04

    Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

  5. Subsurface Microbial Methanotrophic Mats in the Black Sea†

    OpenAIRE

    Treude, Tina; Knittel, Katrin; Blumenberg, Martin; Seifert, Richard; Boetius, Antje

    2005-01-01

    A nodule-shaped microbial mat was found subsurface in sediments of a gas seep in the anoxic Black Sea. This mat was dominated by ANME-1 archaea and consumed methane and sulfate simultaneously. We propose that such subsurface mats represent the initial stage of previously investigated microbial reefs.

  6. Contributions of ectomycorrhizal fungal mats to forest soil respiration

    Directory of Open Access Journals (Sweden)

    C. L. Phillips

    2012-06-01

    Full Text Available Distinct aggregations of fungal hyphae and rhizomorphs, or "mats", formed by some genera of ectomycorrhizal (EcM fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in western Oregon to investigate whether there was higher respiration from mats, and to estimate mat contributions to total soil respiration. We found that areas where Piloderma mats colonized the organic horizon often had higher soil surface flux than non-mats, with the relative increase in respiration averaging 16% across two growing seasons. Both soil physical factors and biochemistry were related to the higher surface flux of mat soils. When soil moisture was high, soil CO2 production was concentrated into near-surface soil horizons where mats tend to colonize, resulting in greater apparent differences in respiration between mat and non-mat soils. Respiration rates were also correlated with the activity of chitin-degrading soil enzymes. This finding supports the notion that the abundance of fungal biomass in EcM mats is an important driver of C and N cycling. We found Piloderma mats present across 57% of the exposed soil, and use this value to estimate a respiratory contribution from mats at the stand-scale of about 9% of total soil respiration. The activity of EcM mats, which includes both EcM fungi and microbial associates, appeared to constitute a substantial portion of total soil respiration in this old-growth Douglas-fir forest.

  7. Ecophysiological Changes in Microbial Mats Incubated in a Greenhouse Collaboratory

    Science.gov (United States)

    Bebout, Brad; DesMarais, David J.; GarciaPichel, Ferran; Hogan, Mary; Jahnke, Linda; Keller, Richard M.; Miller, Scott R.

    2001-01-01

    Microbial mats are modern examples of the earliest microbial communities known. Among the best studied are microbial mats growing in hypersaline ponds managed for the production of salt by Exportadora de Sal, S.A. de C.V., Guerrero Negro, Baja California Sur, Mexico. In May, 2001, we collected mats from Ponds 4 and 5 in this system and returned them to Ames Research Center, where they have been maintained for a period of over nine months. We report here on both the ecophysiological changes occurring in the mats over that period of time as well as the facility in which they were incubated. Mats (approximately 1 sq. meter total area) were incubated in a greenhouse facility modified to provide the mats with natural levels of visible and ultraviolet radiation as well as constantly flowing, temperature-controlled water. Two replicated treatments were maintained, a 'high salinity' treatment (about 120 ppt) and a 'low salinity' treatment (about 90 ppt). Rates of net biological activity (e.g., photosynthesis, respiration, trace gas production) in the mats were relatively constant over the several months, and were similar to rates of activity measured in the field. However, over the course of the incubation, mats in both treatments changed in physical appearance. The most obvious change was that mats in the higher salinity treatments developed a higher proportion of carotenoid pigments (relative to chlorophyll), resulting in a noticeably orange color in the high salinity mats. This trend is also seen in the natural salinity gradient present at the field site. Changes in the community composition of the mats, as assayed by denaturing gradient gel electrophoresis (DGGE), as well as biomarker compounds produced in the mats were also monitored. The degree to which the mats kept in the greenhouse changed from the originally collected mats, as well as differences between high and low salinity mats will be discussed. Additional information is contained in the original extended

  8. Contributions of ectomycorrhizal fungal mats to forest soil respiration

    Directory of Open Access Journals (Sweden)

    C. L. Phillips

    2012-02-01

    Full Text Available Distinct aggregations of fungal hyphae and rhizomorphs, or "mats" formed by some genera of ectomycorrhizal (EcM fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in Western Oregon to investigate whether there was an incremental increase in respiration from mat soils, and to estimate mat contributions to total soil respiration. We found that areas where Piloderma mats colonized the organic horizon often had higher soil surface flux than non-mats, with the incremental increase in respiration averaging 16 % across two growing seasons. Both soil physical factors and biochemistry were related to the higher surface flux of mat soils. When air-filled pore space was low (high soil moisture, soil CO2 production was concentrated into near-surface soil horizons where mats tend to colonize, resulting in greater apparent differences in respiration between mat and non-mat soils. Respiration rates were also correlated with the activity of chitin-degrading soil enzymes. This suggests that the elevated activity of fungal mats may be related to consumption or turnover of chitinous fungal cell-wall materials. We found Piloderma mats present across 57 % of the soil surface in the study area, and use this value to estimate a respiratory contribution from mats at the stand-scale of about 9 % of total soil respiration. The activity of EcM mats, which includes both EcM fungi and microbial associates, was estimated to constitute a substantial portion of total soil respiration in this old-growth Douglas-fir forest.

  9. Permeability of Electro spun Super hydrophobic Nano fiber Mats

    International Nuclear Information System (INIS)

    This paper discusses the fabrication and characterization of electro spun nano fiber mats made up of poly(4-methyl-1-pentene) polymer. The polymer was electro spun in different weight concentrations. The mats were characterized by their basis weight, fiber diameter distribution, contact angles, contact angle hysteresis, and air permeability. All of the electro spun nonwoven fiber mats had water contact angles greater than 150 degrees making them super hydrophobic. The permeabilities of the mats were empirically fitted to the mat basis weight by a linear relation. The experimentally measured air permeabilities were significantly larger than the permeabilities predicted by the Kuwabara model for fibrous media.

  10. Impregnation of thermoplastic resin in jute fiber mat

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Impregnation rate of thermoplastic resin (polypropylene) in jute fiber mat and influence of relative factors on impregnation were studied,aiming to develop the continuous melt impregnation technique and to investigate the effect of impregnation rate and temperature on processing conditions and mechanical properties of natural fiber mat-reinforced thermoplastics.Influence of pressure on porosity of fiber mat and effect of melt viscosity on impregnation rate were also investigated.The modified capillary rheometer was used as apparatus and experimental data were analyzed based on the one-dimension Darcy's law.Results showed that at a given pressure,the impregnation rate is inversely proportional to melt viscosity and jute fiber mat has higher porosity than glass fiber mat.The architecture,compressibility,permeability and fiber diameter of jute fiber mat were compared with those of glass fiber mat and their effects on impregnation were discussed further.It could be seen that the average diameter of jute fiber is much bigger;the porosity of jute fiber mat is significantly higher and inner bundle impregnation does not exist in jute fiber mat.Therefore,it is not difficult to understand why the impregnation rate in jute fiber mat is 3.5 times higher and permeability is 14 times greater.Kozeny constants of jute and glass fiber mats calculated based on the capillary model are 2950 and 442,respectively.

  11. Mekh-mat entrance examinations problems

    CERN Document Server

    Vardi, I

    2000-01-01

    This paper provides a complete solution set to 25 ``killer problems'' given to Jewish candidates to the Mekh--mat at Moscow State University during the 1970's and 1980's. Typically, the problems are at the mathematical olympiad level and some feature interesting theorems. However, a number of the problems are flawed, or even completely wrong. The paper therefore includes an evaluation of the problems in the style of a referee report.

  12. Unravelling Colletotrichum species associated with Camellia: employing ApMat and GS loci to resolve species in the C. gloeosporioides complex

    OpenAIRE

    Liu, F; Weir, B S; Damm, U.; Crous, P.W.; Wang, Y; Liu, B.; Wang, M.(Central China Normal University, Wuhan, China); Zhang, M.; L. Cai

    2015-01-01

    We investigated the phylogenetic diversity of 144 Colletotrichum isolates associated with symptomatic and asymptomatic tissues of Camellia sinensis and other Camellia spp. from seven provinces in China (Fujian, Guizhou, Henan, Jiangxi, Sichuan, Yunnan, Zhejiang), and seven isolates obtained from other countries, including Indonesia, UK, and the USA. Based on multi-locus (ACT, ApMat, CAL, GAPDH, GS, ITS, TUB2) phylogenetic analyses and phenotypic characters, 11 species were distinguished, incl...

  13. Adhesins of Bartonella spp.

    Science.gov (United States)

    O'Rourke, Fiona; Schmidgen, Thomas; Kaiser, Patrick O; Linke, Dirk; Kempf, Volkhard A J

    2011-01-01

    Adhesion to host cells represents the first step in the infection process and one of the decisive features in the pathogenicity of Bartonella spp. B. henselae and B. quintana are considered to be the most important human pathogenic species, responsible for cat scratch disease, bacillary angiomatosis, trench fever and other diseases. The ability to cause vasculoproliferative disorders and intraerythrocytic bacteraemia are unique features of the genus Bartonella. Consequently, the interaction with endothelial cells and erythrocytes is a focus in Bartonella research. The genus harbours a variety of trimeric autotransporter adhesins (TAAs) such as the Bartonella adhesin A (BadA) of B. henselae and the variably expressed outer-membrane proteins (Vomps) of B. quintana, which display remarkable variations in length and modular construction. These adhesins mediate many of the biologically-important properties of Bartonella spp. such as adherence to endothelial cells and extracellular matrix proteins and induction of angiogenic gene programming. There is also significant evidence that the laterally acquired Trw-conjugation systems of Bartonella spp. mediate host-specific adherence to erythrocytes. Other potential adhesins are the filamentous haemagglutinins and several outer membrane proteins. The exact molecular functions of these adhesins and their interplay with other pathogenicity factors (e.g., the VirB/D4 type 4 secretion system) need to be analysed in detail to understand how these pathogens adapt to their mammalian hosts. PMID:21557057

  14. Charpy V, an application in Mat lab

    International Nuclear Information System (INIS)

    The obtained results with the system Charpy VV1 designed in Mat lab for the estimate of parameters of three mathematical models are shown. The adjustment of data is used to determine the fracture energy, the lateral expansion and the percentage of ductility of steels coming from the reactor vessels of Laguna Verde, Veracruz. The data come from test tubes type Charpy V of irradiated material and not irradiated. To verify our results they were compared with those obtained by General Electric of data coming from the Laguna Verde nuclear power plant. (Author)

  15. Mineralogy of iron microbial mats from Loihi Seamount

    OpenAIRE

    BrandyMarieToner; ThelmaSBerquó; F. MarcMichel; AlexisSTempleton; KatrinaJEdwards

    2012-01-01

    Extensive mats of Fe oxyhydroxides and associated Fe-oxidizing microbial organisms form in diverse geochemical settings – freshwater seeps to deep-sea vents – where ever opposing Fe(II)-oxygen gradients prevail. The mineralogy, reactivity, and structural transformations of Fe oxyhydroxides precipitated from submarine hydrothermal fluids within microbial mats remains elusive in active and fossil systems. In response, a study of Fe microbial mat formation at the Loihi Seamount was conducted t...

  16. Mineralogy of Iron Microbial Mats from Loihi Seamount

    OpenAIRE

    Toner, Brandy M.; Berquó, Thelma S.; Michel, F. Marc; Sorensen, Jeffry V.; Templeton, Alexis S.; Edwards, Katrina J.

    2012-01-01

    Extensive mats of Fe oxyhydroxides and associated Fe-oxidizing microbial organisms form in diverse geochemical settings – freshwater seeps to deep-sea vents – where ever opposing Fe(II)-oxygen gradients prevail. The mineralogy, reactivity, and structural transformations of Fe oxyhydroxides precipitated from submarine hydrothermal fluids within microbial mats remains elusive in active and fossil systems. In response, a study of Fe microbial mat formation at the Loihi Seamount was conducted to ...

  17. Mats Reidius : Rootsi taluliit tahab üle minna eurole / Mats Reidius ; interv. Annika Poldre

    Index Scriptorium Estoniae

    Reidius, Mats

    2003-01-01

    Rootsi majandusteadlane Mats Reidius Rootsi põllumajanduse olukorrast enne Rootsi liitumist EL-iga, Rootsi talunike võitudest-kaotustest El-iga ühinemisel, muutustest Rootsi toiduaineturul pärast EL-iga liitumist, Rootsi talunike arvamusest euro kohta

  18. Diel metabolomics analysis of a hot spring chlorophototrophic microbial mat leads to new hypotheses of community member metabolisms

    Directory of Open Access Journals (Sweden)

    Young-Mo eKim

    2015-04-01

    Full Text Available Dynamic environmental factors such as light, nutrients, salt, and temperature continuously affect chlorophototrophic microbial mats, requiring adaptive and acclimative responses to stabilize composition and function. Quantitative metabolomics analysis can provide insights into metabolite dynamics for understanding community response to such changing environmental conditions. In this study, we quantified volatile organic acids, polar metabolites (amino acids, glycolytic and citric acid cycle intermediates, nucleobases, nucleosides, and sugars, wax esters, and polyhydroxyalkanoates, resulting in the identification of 104 metabolites and related molecules in thermal chlorophototrophic microbial mat cores collected over a diel cycle in Mushroom Spring, Yellowstone National Park. A limited number of predominant taxa inhabit this community and their functional potentials have been previously identified through metagenomic and metatranscriptomic analyses and in situ metabolisms, and metabolic interactions among these taxa have been hypothesized. Our metabolomics results confirmed the diel cycling of photorespiration (e.g. glycolate and fermentation (e.g. acetate, propionate, and lactate products, the carbon storage polymers polyhydroxyalkanoates, and dissolved gases (e.g. H2 and CO2 in the waters overlying the mat, which were hypothesized to occur in major mat chlorophototrophic community members. In addition, we have formulated the following new hypotheses: 1 the morning hours are a time of biosynthesis of amino acids, DNA, and RNA; 2 photo-inhibited cells may also produce lactate via fermentation as an alternate metabolism; 3 glycolate and lactate are exchanged among Synechococcus and Roseiflexus spp.; and 4 fluctuations in many metabolite pools (e.g. wax esters at different times of day result from species found at different depths within the mat responding to temporal differences in their niches

  19. New universal matK primers for DNA barcoding angiosperms

    Institute of Scientific and Technical Information of China (English)

    Jing YU; Jian-Hua XUE; Shi-Liang ZHOU

    2011-01-01

    The chloroplast maturase K gene (matK) is one of the most variable coding genes of angiosperms and has been suggested to be a "barcode" for land plants. However, matK exhibits low amplification and sequencing rates due to low universality of currently available primers and mononucleotide repeats. To resolve these technical problems, we evaluated the entire matK region to find a region of 600-800 bp that is highly variable, represents the best of all matK regions with priming sites conservative enough to design universal primers, and avoids the mononucleotide repeats. After careful evaluation, a region in the middle was chosen and a pair of primers named natK472F and matK1248R was designed to amplify and sequence the matK fragment of approximately 776 bp. This region encompasses the most variable sites, represents the entire matK region best, and also exhibits high amplification rates and quality of sequences. The universality of this primer pair was tested using 58 species from 47 families of angiosperm plants. The primers showed a strong amplification (93.1%) and sequencing (92.6%)successes in the species tested. We propose that the new primers will solve, in part, the problems encountered when using matK and promote the adoption of matK as a DNA barcode for angiosperms.

  20. Use of palm-mat geotextiles for rainsplash erosion control

    Science.gov (United States)

    Bhattacharyya, R.; Fullen, M. A.; Davies, K.; Booth, C. A.

    2010-07-01

    Soil detachment by raindrop action (rainsplash erosion) is a very important subprocess of erosion by water. It is a particular problem in the UK as most soils are sandy or loamy sand in texture and lands have gentle to medium slope. However, few studies report potential rainsplash erosion control options under field conditions. Hence, the utilization of palm-mat geotextiles as a rainsplash erosion control technique was investigated at Hilton, east Shropshire, U.K. (52°33'5.7″ N, 2°19'18.3″ W). Geotextile-mats constructed from Borassus aethiopum (Borassus palm of West Africa) and Mauritia flexuosa (Buriti palm of South America) leaves are termed Borassus mats and Buriti mats, respectively. Two-year field experiments were conducted at Hilton to study the effects of emplacing Borassus and Buriti mats on rainsplash erosion of a loamy sand soil. Two sets (12 plots each) of experiments were established to study the effects of these mats on splash height and splash erosion. Splash height needs to be known to assess the transport mechanism of major soil fraction and its constituents on sloping land by rainsplash. In both sets, six randomly-selected plots were covered with mats, and the rest were bare. Results (during 22/01/2007‒23/01/2009; total precipitation = 1731.5 mm) show that Borassus mat-covered plots had ˜ 89% ( P 0.05) effect in rainsplash erosion control during that period, although plots with Buriti mats significantly ( P 0.05) improve selected soil properties (i.e., soil organic matter, particle size distribution, aggregate stability and total soil carbon) as soil organic matter (SOM) input from mat-decomposition was much less than total SOM content. However, the changes in fine and medium sand contents (after 2 years) in the Borassus covered plots were significantly ( P < 0.05; n = 6) related to the total rainsplash erosion during 2007‒2009. Emplacement of Borassus and Buriti mats on bare soils did not decrease SOM contents after 2 years, indicating

  1. Stromatolites, Metals, Statistics and Microbial Mats: A Complex Interplay

    Science.gov (United States)

    Spear, J. R.

    2014-12-01

    Initially thought to be relatively 'simple' ecosystems for study, microbial mats have long been considered ideal for any number of research questions. Microbial mats can be found in any number of environments, both natural and manmade, and are typically dependent upon the physiochemical environment for their structure, maintenance and longevity. Ultimately, these and other parameters govern community whereby a microbial mat provides overall ecosystem services to their environment. On the edge of a hotspring in Yellowstone National Park we have found an active microbial mat community that can form a laminated, lithified, accretionary structure that is likely the best example of a living and growing stromatolite. In the outfall channel of the sulfidic Stinking Spring, Utah, we have found examples of both naturally occurring laminated and floating mats where the carbon flux is controlled by abiotic degassing of CO2 rather than metabolism. δ13C-bicarbonate uptake experiments reveal an autotrophic growth rate of 0 - 0.16%/day while δ13C-acetate reveals a higher heterotrophic growth rate of 0.03 - 0.65%/day, which highlights the role of heterotrophs in these mats. Similar growth experiments on Little Hot Creek, California laminated microbial mats reveal a trend for top-down microbial growth with similar microbial taxonomy and diversity to other mat-types. Of a curious note is that incubation experiments with Little Hot Creek mats reveals the importance of particular metals in mat structure and function. Statistically, alpha- and beta-diversity metrics are often used to characterize microbial communities in such systems, but from an analysis of a wastewater treatment system, Hill diversities can better interpret the effective number of species to produce an ecologically intuitive quantity to better understand a microbial mat ecosystem.

  2. SPP1-mediated plasmid transduction.

    OpenAIRE

    Canosi, U; Lüder, G; Trautner, T A

    1982-01-01

    The virulent Bacillus subtilis phage SPP1 transduces plasmid DNA. Plasmid-transducing phages contain only plasmid DNA. Such DNA represents a concatemer of monomeric plasmid molecules with the molecular weight of mature SPP1 DNA. Biological parameters of plasmid transduction are described.

  3. Matting Of Hair Due To ′Sunsilk′ Shampoo

    OpenAIRE

    Nadeem Mohd

    1995-01-01

    Matting of hair been reported from time to time due to treatment of hair with detergent, shampoos, waving lotions, setting lotions and bleaches. A case of matting of hairs in a young girl due to a change in the brand of shampoo is reported.

  4. Matting Of Hair Due To ′Sunsilk′ Shampoo

    Directory of Open Access Journals (Sweden)

    Nadeem Mohd

    1995-01-01

    Full Text Available Matting of hair been reported from time to time due to treatment of hair with detergent, shampoos, waving lotions, setting lotions and bleaches. A case of matting of hairs in a young girl due to a change in the brand of shampoo is reported.

  5. Egg albumen - a promising material for fabrication of nanoporous mats

    Directory of Open Access Journals (Sweden)

    Zhao Lei

    2016-01-01

    Full Text Available The natural protein, egg albumen, is used for fabrication of nanoporous mats by bubbfil electrospinning. In our experiment, starch is used as an additive. By suitable choices of the spinning conditions, a mat with nanopores can be produced, and the spinning process is tenable by controlling the thermodynamic properties of spun solution and spinning environment.

  6. Matérialisme et passions

    OpenAIRE

    Cottegnies, Line; Léon-Miehe, Anne; Pierre LURBE; Moreau, Pierre-François; Thomson, Ann; Weber, Dominique

    2014-01-01

    La modernité, dès ses débuts, attribue un rôle-clef aux passions : qu’elles soient hostiles à la Raison ou au contraire ses alliées, dangereuses ou fascinantes, elles marquent le rôle du corps, du désir, du langage et de l’imagination dans la nature de l’homme. La même époque voit se développer différentes variantes du matérialisme. Presque toutes réévaluent ce que la raison classique avait tendance à réprimer ou à considérer comme révélateur de la faiblesse humaine : le corps et tout ce qui,...

  7. Vizualizace XML schémat

    OpenAIRE

    Slavětínský, Václav

    2008-01-01

    Bakalářská práce se zabývá návrhem a implementací aplikace, která slouží k převodu W3C XML schémat do interaktivního diagramu ve formátu SVG (Scalable Vector Graphics). Diagram poskytuje údaje získané ze schématu ? údaje o elementech a atributech, a jejich přípustné struktuře. Proto je vhodný jako součást dokumentace XML souborů vyhovujících schématu. Generovaná grafika je interaktivní a přehledná, uživatelům má usnadnit pochopení XML dokumentů a orientaci v nich. Aplikace je napsána v jazyce...

  8. Chimie des matériaux hybrides

    OpenAIRE

    Sanchez, Clément

    2013-01-01

    Cours : chimie des matériaux hybrides Depuis plus d’une vingtaine d’années, les méthodes d’élaboration de nanomatériaux inorganiques ou hybrides reposant sur la « chimie douce » suscitent un très fort intérêt, aussi bien dans le monde universitaire qu’industriel. Ces méthodes de synthèse mettent en jeu des réactions de « polymérisation » au sens large s’effectuant à température ambiante, en solvant aqueux ou organique, à partir de précurseurs moléculaires ou nanoparticulaires. Ces conditions ...

  9. Chlorophyll and carotenoid pigments in solar saltern microbial mats

    Science.gov (United States)

    Villanueva, Joan; Grimalt, Joan O.; de Wit, Rutger; Keely, Brendan J.; Maxwell, James R.

    1994-11-01

    The distributions of carotenoids, chlorophylls, and their degradation products have been studied in two microbial mat systems developed in the calcite and calcite/gypsum evaporite domains of a solar saltern system. Phormidium valderianum and Microcoleus chthonoplastes are the dominant cyanobacterial species, respectively, and large amounts of Chloroflexus-like bacteria occur in the carbonate/gypsum mat. In both systems, the major pigments are chlorophyll a, zeaxanthin, β-carotene and myxoxanthophyll, which originate from these mat-building cyanobacteria. This common feature contrasts with differences in other pigments that are specific for each mat community. Thus, chlorophyll c and fucoxanthin, reflecting diatom inputs, are only found in the calcite mat, whereas the calcite/gypsum mat contains high concentrations of bacteriochlorophylls c produced by the multicellular green filamentous bacteria. In both cases, the depth concentration profiles (0-30 and 0-40 mm) show a relatively good preservation of the cyanobacterial carotenoids, zeaxanthin, β-carotene, myxoxanthophyll, and echinenone. This contrasts with the extensive biodegradation of cyanobacterial remains observed microscopically. Fucoxanthin in the calcite mat is also transformed at a faster rate than the cyanobacterial carotenoids. Chlorophyll a, the major pigment in both mats, exhibits different transformation pathways. In the calcite/gypsum mat, it is transformed via C-13 2 carbomethoxy defunctionalization prior to loss of the phytyl chain, leading to the formation of pyrophaeophytin a and, subsequently, pyrophaeophorbide a. On the other hand, the occurrence of the enzyme chlorophyllase, attributed to diatoms in the calcite mat, gives rise to extensive phytyl hydrolysis, with the formation of chlorophyllide a, pyrophaeophorbide a and, in minor proportion, phaeophorbide a. Studies of the sources of the photosynthetic pigments and of their transformation pathways in such simplified ecosystems provide a

  10. Elastic-plastic behavior of non-woven fibrous mats

    Science.gov (United States)

    Silberstein, Meredith N.; Pai, Chia-Ling; Rutledge, Gregory C.; Boyce, Mary C.

    2012-02-01

    Electrospinning is a novel method for creating non-woven polymer mats that have high surface area and high porosity. These attributes make them ideal candidates for multifunctional composites. Understanding the mechanical properties as a function of fiber properties and mat microstructure can aid in designing these composites. Further, a constitutive model which captures the membrane stress-strain behavior as a function of fiber properties and the geometry of the fibrous network would be a powerful design tool. Here, mats electrospun from amorphous polyamide are used as a model system. The elastic-plastic behavior of single fibers are obtained in tensile tests. Uniaxial monotonic and cyclic tensile tests are conducted on non-woven mats. The mat exhibits elastic-plastic stress-strain behavior. The transverse strain behavior provides important complementary data, showing a negligible initial Poisson's ratio followed by a transverse:axial strain ratio greater than -1:1 after an axial strain of 0.02. A triangulated framework has been developed to emulate the fibrous network structure of the mat. The micromechanically based model incorporates the elastic-plastic behavior of single fibers into a macroscopic membrane model of the mat. This representative volume element based model is shown to capture the uniaxial elastic-plastic response of the mat under monotonic and cyclic loading. The initial modulus and yield stress of the mat are governed by the fiber properties, the network geometry, and the network density. The transverse strain behavior is linked to discrete deformation mechanisms of the fibrous mat structure including fiber alignment, fiber bending, and network consolidation. The model is further validated in comparison to experiments under different constrained axial loading conditions and found to capture the constraint effect on stiffness, yield, post-yield hardening, and post-yield transverse strain behavior. Due to the direct connection between

  11. Benthic Marine Cyanobacterial Mat Ecosystems: Biogeochemistry and Biomarkers

    Science.gov (United States)

    DesMarais, David J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Cyanobacterial mats are complete ecosystems that can include processes of primary production, diagenesis and lithification. Light sustains oxygenic photosynthesis, which in turn provides energy, organic matter and oxygen to the community. Due to both absorption and scattering phenomena, incident light is transformed with depth in the mat, both in intensity and spectral composition. Mobile photo synthesizers optimize their position with respect to this light gradient. When photosynthesis ceases at night, the upper layers of the mat become reduced and sulfidic. Counteracting gradients of oxygen and sulfide combine to provide daily-contrasting environments separated on a scale of a few mm. The functional complexity of mats, coupled with the highly proximal and ordered spatial arrangement of biota, offers the potential for a staggering number of interactions. At a minimum, the products of each functional group of microorganisms affect the other groups both positively and negatively. For example, cyanobacteria generate organic matter (potential substrates) but also oxygen (a toxin for many anaerobes). Anaerobic activity recycles nutrients to the photosynthesizers but also generates potentially toxic sulfide. The combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods, and to various depths in the mat. Observations of mats have produced numerous surprises. For example, obligately anaerobic processes can occur in the presence of abundant oxygen, highly reduced gases are produced in the presence of abundant sulfate, meiofauna thrive at high sulfide concentrations, and the mats' constituent populations respond to environmental changes in complex ways. While photosynthetic bacteria dominate the biomass and productivity of the mat, nonphotosynthetic, anaerobic processes constitute the ultimate biological filter on the ecosystem's emergent biosignatures, including those

  12. Antimicrobial activity of Leuzea spp. and Nigella spp. extracts

    Czech Academy of Sciences Publication Activity Database

    Kokoška, L.; Janovská, D.; Havlík, J.; Rada, V.; Vaněk, Tomáš; Nepovím, Aleš

    Kiel, 2003. s. 173. [Annual Congress of the Society for Medicinal Plant Research /51./. 31.08.2003-04.09.2003, Kiel] R&D Projects: GA ČR GA525/02/0257; GA ČR GP525/02/D107 Institutional research plan: CEZ:AV0Z4055905 Keywords : antimicrobial activity * Leuzea spp. * Nigella spp. Subject RIV: CE - Biochemistry

  13. Geosynthetic Reinforcement of Sand-Mat Layer above Soft Ground

    Directory of Open Access Journals (Sweden)

    Jong-Beom Park

    2013-11-01

    Full Text Available In order to improve the bearing capacity of soft ground for the purpose of getting trafficability of construction vehicles, the reinforcement of geosynthetics for sand-mat layers on soft ground has often been used. As the strength of the geosynthetics increases, and the sand-mat system becomes stronger, the bearing capacity of sand-mat systems will be increased. The depths of geosynthetics, reinforced in sand-mat layers, were varied with respect to the width of footing. The tensile strengths of geosynthetics were also varied to evaluate the effect of reinforcement on the bearing capacity of soft ground. The dispersion angles, with varying sand-mat thicknesses, were also determined in consideration of the tensile strength of geosynthetics and the depths of reinforcement installations. The bearing capacity ratios, with the variation of footing width and reinforced embedment depth, were determined for the geosynthetics-only, reinforced soft ground, 1-layer sand-mat system and 2-layer sand-mat system against the non-reinforced soft ground. From the test results of various models, a principle that better explains the concept of geosynthetic reinforcement has been found. On the basis of this principle, a new bearing capacity equation for practical use in the design of geosynthetically reinforced soft ground has been proposed by modifying Yamanouchi’s equation.

  14. Monitoring Survival and Preservation of Recent Cyanobacterial Mats

    Science.gov (United States)

    Chacon, Elizabeth; Negron-Mendoza, Alicia; Camargo, Claudia

    2010-05-01

    Through geobiological evolution cyanobacterial mats have played a fundamental role through the development of early microbial carbonate ecosystems and through the sustainment of major biogeochemical cycling in the biosphere; nonetheless their sedimentary record is relatively modest in comparison with their biological impact; this apparent under-representation in the fossil record may be due to their intrinsic poor preservation potential but also to our inability to recognize some subtle microbial signatures. Modern studies on cyanobacterial mats involve high-tech molecular approaches to identify, analyze and even quantify the genetic diversity of ancient and modern microbial mats, yet the physical changes of mats, their survival and preservation potential, remain almost unknown and experimentally poorly explored. If we are going to succeed in the astrobiological quest for traces of life we should develop integrated methods and diagnostic features to address biosignatures at both, the phenotypic and genotypic levels when possible. The correct recognition and interpretation of biosignatures in this emerging field needs, aside these fine molecular tools, plain experimental approaches to test microbial resistance, survival and preservation potential of microbial mats after exposure to diagenetic changes. In this work we study some effects on fresh slices of cyanobacterial mats and cultures of specific external simulated agents that normally occur during diagenesis such as dehydratation, heat, abrasion or pressure among others. Samples from different cyanobacterial communities associated to carbonates collected from different rivers and falls around Mexico were subjected to same lab procedures. Physical and textural changes were monitored through microscopic analysis where cell integrity and mat cohesiveness were analyzed before and after treatment. Preliminary results show that mats enriched in halite and clay sediments were preferentially preserved; however those mats

  15. Bartonella spp. in Bats, Kenya

    OpenAIRE

    Kosoy, Michael; Bai, Ying; Lynch, Tarah; Kuzmin, Ivan V.; Niezgoda, Michael; Franka, Richard; Agwanda, Bernard; Breiman, Robert F.; Rupprecht, Charles E.

    2010-01-01

    We report the presence and diversity of Bartonella spp. in bats of 13 insectivorous and frugivorous species collected from various locations across Kenya. Bartonella isolates were obtained from 23 Eidolon helvum, 22 Rousettus aegyptiacus, 4 Coleura afra, 7 Triaenops persicus, 1 Hipposideros commersoni, and 49 Miniopterus spp. bats. Sequence analysis of the citrate synthase gene from the obtained isolates showed a wide assortment of Bartonella strains. Phylogenetically, isolates clustered in s...

  16. Methanogenesis from Methylated Amines in a Hypersaline Algal Mat

    OpenAIRE

    King, Gary M.

    1988-01-01

    Methane ebullition and high rates of methane production were observed in sediments of a hypersaline pond (180‰) which contained sulfate in excess of 100 mM. The highest rates of methane production were observed in surface sediments associated with an algal mat dominated by a Spirulina sp. The mat contained a methylated amine, glycine betaine (GBT), at levels which accounted for up to 20% of the total mat nitrogen. GBT was apparently the source of trimethylamine (TMA), which was also present i...

  17. Electrospun graphene-ZnO nanofiber mats for photocatalysis applications

    International Nuclear Information System (INIS)

    Graphene-decorated zinc oxide (G-ZnO) nanofibers were fabricated, for the first time, by electrospinning. The effect of graphene concentration on the properties of G-ZnO mats were investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and thermo gravimetric analysis. The G-ZnO mats decorated with 0.5 wt.% of graphene showed excellent photocatalytic activity through degradation of methylene blue under UV irradiation. The highest photocatalytic activity (80% degradation) was observed for 0.5 wt.% G-ZnO mats annealed at 400 °C after 4 h of UV irradiation

  18. Electrospun graphene-ZnO nanofiber mats for photocatalysis applications

    Science.gov (United States)

    An, Seongpil; Joshi, Bhavana N.; Lee, Min Wook; Kim, Na Young; Yoon, Sam S.

    2014-03-01

    Graphene-decorated zinc oxide (G-ZnO) nanofibers were fabricated, for the first time, by electrospinning. The effect of graphene concentration on the properties of G-ZnO mats were investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and thermo gravimetric analysis. The G-ZnO mats decorated with 0.5 wt.% of graphene showed excellent photocatalytic activity through degradation of methylene blue under UV irradiation. The highest photocatalytic activity (80% degradation) was observed for 0.5 wt.% G-ZnO mats annealed at 400 °C after 4 h of UV irradiation.

  19. Water flow and solute transport in floating fen root mats

    Science.gov (United States)

    Stofberg, Sija F.; EATM van der Zee, Sjoerd

    2015-04-01

    Floating fens are valuable wetlands, found in North-Western Europe, that are formed by floating root mats when old turf ponds are colonized by plants. These terrestrialization ecosystems are known for their biodiversity and the presence of rare plant species, and the root mats reveal different vegetation zones at a small scale. The vegetation zones are a result of strong gradients in abiotic conditions, including groundwater dynamics, nutrients and pH. To prevent irreversible drought effects such as land subsidence and mineralization of peat, water management involves import of water from elsewhere to maintain constant surface water levels. Imported water may have elevated levels of salinity during dry summers, and salt exposure may threaten the vegetation. To assess the risk of exposure of the rare plant species to salinity, the hydrology of such root mats must be understood. Physical properties of root mats have scarcely been investigated. We have measured soil characteristics, hydraulic conductivity, vertical root mat movement and groundwater dynamics in a floating root mat in the nature reserve Nieuwkoopse Plassen, in the Netherlands. The root mat mostly consists of roots and organic material, in which the soil has a high saturated water content, and strongly varies in its stage of decomposition. We have found a distinct negative correlation between degree of decomposition and hydraulic conductivity, similar to observations for bogs in the literature. Our results show that the relatively young, thin edge of the root mat that colonizes the surface water has a high hydraulic conductivity and floats in the surface water, resulting in very small groundwater fluctuations within the root mat. The older part of the root mat, that is connected to the deeper peat layers is hydrologically more isolated and the material has a lower conductivity. Here, the groundwater fluctuates strongly with atmospheric forcing. The zones of hydraulic properties and vegetation, appear to

  20. Thermal Protection System Materials (TPSM): 3D MAT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The 3D MAT Project seeks to design and develop a game changing Woven Thermal Protection System (TPS) technology tailored to meet the needs of the Orion...

  1. Structure and function of cyanobacterial mats in wetlands of Belize

    Czech Academy of Sciences Publication Activity Database

    Komárek, Jiří; Sirová, D.; Komárková-Legnerová, Jaroslava; Rejmánková, E.

    Boca Raton : CRC Press, 2015 - (Entry, J.; Gottlieb, A.; Jayachandran, K.; Ogram, A.), 194-217 ISBN 978-1-4987-1183-8 Institutional support: RVO:67985939 ; RVO:60077344 Keywords : Belize * swamps * cyanobacterial mats Subject RIV: EF - Botanics

  2. Extraction of High Molecular Weight DNA from Microbial Mats

    OpenAIRE

    Bey, Benjamin S.; Fichot, Erin B.; Norman, R. Sean

    2011-01-01

    Successful and accurate analysis and interpretation of metagenomic data is dependent upon the efficient extraction of high-quality, high molecular weight (HMW) community DNA. However, environmental mat samples often pose difficulties to obtaining large concentrations of high-quality, HMW DNA. Hypersaline microbial mats contain high amounts of extracellular polymeric substances (EPS)1 and salts that may inhibit downstream applications of extracted DNA. Direct and harsh methods are often used i...

  3. Photosynthate Partitioning and Fermentation in Hot Spring Microbial Mat Communities

    OpenAIRE

    Nold, S C; Ward, D M

    1996-01-01

    Patterns of (sup14)CO(inf2) incorporation into molecular components of the thermophilic cyanobacterial mat communities inhabiting hot springs located in Yellowstone National Park and Synechococcus sp. strain C1 were investigated. Exponentially growing Synechococcus sp. strain C1 partitioned the majority of incorporated (sup14)CO(inf2) into protein, low-molecular-weight metabolites, and lipid fractions (45, 22, and 18% of total incorporated carbon, respectively). In contrast, mat cores from va...

  4. NITRIFICATION AND NITRIFYING BACTERIA IN A COASTAL MICROBIAL MAT

    Directory of Open Access Journals (Sweden)

    Haoxin eFan

    2015-12-01

    Full Text Available The first step of nitrification, the oxidation of ammonia to nitrite, can be performed by ammonia-oxidizing archaea (AOA or ammonium-oxidizing bacteria (AOB. We investigated the presence of these two groups in three structurally different types of coastal microbial mats that develop along the tidal gradient on the North Sea beach of the Dutch barrier island Schiermonnikoog. The abundance and transcription of amoA, a gene encoding for the alpha subunit of ammonia monooxygenase that is present in both AOA and AOB, were assessed and the potential nitrification rates in these mats were measured. The potential nitrification rates in the three mat types were highest in autumn and lowest in summer. AOB and AOA amoA genes were present in all three mat types. The composition of the AOA and AOB communities in the mats of the tidal and intertidal stations, based on the diversity of amoA, were similar and clustered separately from the supratidal microbial mat. In all three mats AOB amoA genes were significantly more abundant than AOA amoA genes. The abundance of neither AOB nor AOA amoA genes correlated with the potential nitrification rates, but AOB amoA transcripts were positively correlated with the potential nitrification rate. The composition and abundance of amoA genes seemed to be partly driven by salinity, ammonium, temperature and the nitrate/nitrite concentration. We conclude that AOB are responsible for the bulk of the ammonium oxidation in these coastal microbial mats.

  5. Nitrification and Nitrifying Bacteria in a Coastal Microbial Mat

    Science.gov (United States)

    Fan, Haoxin; Bolhuis, Henk; Stal, Lucas J.

    2015-01-01

    The first step of nitrification, the oxidation of ammonia to nitrite, can be performed by ammonia-oxidizing archaea (AOA) or ammonium-oxidizing bacteria (AOB). We investigated the presence of these two groups in three structurally different types of coastal microbial mats that develop along the tidal gradient on the North Sea beach of the Dutch barrier island Schiermonnikoog. The abundance and transcription of amoA, a gene encoding for the alpha subunit of ammonia monooxygenase that is present in both AOA and AOB, were assessed and the potential nitrification rates in these mats were measured. The potential nitrification rates in the three mat types were highest in autumn and lowest in summer. AOB and AOA amoA genes were present in all three mat types. The composition of the AOA and AOB communities in the mats of the tidal and intertidal stations, based on the diversity of amoA, were similar and clustered separately from the supratidal microbial mat. In all three mats AOB amoA genes were significantly more abundant than AOA amoA genes. The abundance of neither AOB nor AOA amoA genes correlated with the potential nitrification rates, but AOB amoA transcripts were positively correlated with the potential nitrification rate. The composition and abundance of amoA genes seemed to be partly driven by salinity, ammonium, temperature, and the nitrate/nitrite concentration. We conclude that AOB are responsible for the bulk of the ammonium oxidation in these coastal microbial mats. PMID:26648931

  6. Characterization of Carbon Mat Thermoplastic Composites: Flow and Mechanical Properties

    OpenAIRE

    Caba, Aaron C.

    2005-01-01

    Carbon mat thermoplastics (CMT) consisting of 12.7 mm or 25.4 mm long, 7.2 micrometer diameter, chopped carbon fibers in a polypropylene (PP) or poly(ethylene terephthalate) (PET) thermoplastic matrix were manufactured using the wetlay technique. This produces a porous mat with the carbon fibers well dispersed and randomly oriented in a plane. CMT composites offer substantial cost and weight savings over typical steel construction in new automotive applications. In production vehicles, aut...

  7. The biogeochemistry of microbial mats, stromatolites and the ancient biosphere

    Science.gov (United States)

    Desmarais, D. J.; Canfield, D. E.

    1991-01-01

    Stromatolites offer an unparalleled geologic record of early life, because they constitute the oldest and most abundant recognizable remains of microbial ecosystems. Microbial mats are living homologs of stromatolites; thus, the physiology of the microbiota as well as the processes which create those features of mats (e.g., biomarker organic compounds, elemental and stable isotopic compositions) which are preserved in the ancient record. Observations of the carbon isotopic composition (delta C-13) of stromatolites and microbial mats were made and are consistent with the hypothesis that atmospheric CO2 concentrations have declined by at least one to two orders of magnitude during the past 2.5 Ga. Whereas delta C-13 values of carbonate carbon average about 0 permil during both the early and mid-Proterozoic, the delta C-13 values of stromatolitic organic matter increase from an average of -35 between 2.0 and 2.6 Ga ago to an average of about -28 about 1.0 Ga ago. Modern microbial mats in hypersaline environments have delta C-13 values typically in the range of -5 to -9, relative to an inorganic bicarbonate source at 0 permil. Both microbial mats and pur cultures of cyanobacteria grown in waters in near equilibrium with current atmospheric CO2 levels exhibit minimal discrimination against C-13. In contrast, hot spring cyanobacterial mats or cyanobacterial cultures grown under higher CO2 levels exhibit substantially greater discrimination. If care is taken to compare modern mats with stromatolites from comparable environments, it might be possible to estimate ancient levels of atmospheric CO2. In modern microbial mats, a tight coupling exists between photosynthetic organic carbon production and subsequent carbon oxidation, mostly by sulfate reduction. The rate of one process fuels a high rate of the other, with much of the sulfate reduction occurring within the same depth interval as oxygenic photosynthesis. Other aspects of this study are presented.

  8. High universality of matK primers for barcoding gymnosperms

    Institute of Scientific and Technical Information of China (English)

    Yan LI; Lian-Ming GAO; RAM C.POUDEL; De-Zhu Li; Alan FORREST

    2011-01-01

    DNA barcoding is a tool to provide rapid and accurate taxonomic identification using a standard DNA region. A two-marker combination of rnatK+rbcL was formally proposed as the core barcode for land plants by the Consortium for the Barcode of Life Plant Working Group. However, there are currently no barcoding primers for matK showing high universality in gymnosperms. We used 57 gymnosperm species representing 40 genera, 11families and four subclasses to evaluate the universality of nine candidate matK primers and one rbcL primer in this study. Primer (1F/724R) of rbcL is proposed here as a universal primer for gymnosperms due to high universality. One of the nine candidate matK primers (Gym_F1A/Gym_R1A) is proposed as the best "universal" matK primer for gynnosperms because of high polymerase chain reaction success and routine generation of high quality bidirectional sequences. A specific matK primer for Ephedra was newly designed in this study, which performed well on the sampled species. The primers proposed here for rbcL and matK can be easily and successfully amplified for most gymnosperms.

  9. Invasive algal mats degrade coral reef physical habitat quality

    Science.gov (United States)

    Martinez, Jonathan A.; Smith, Celia M.; Richmond, Robert H.

    2012-03-01

    Invasive species alter the ecology of marine ecosystems through a variety of mechanisms or combination of mechanisms. This study documented critical physical parameters altered by the invasive red macroalga Gracilaria salicornia in situ, including: reduced irradiance, increased sedimentation, and marked variation in diurnal dissolved oxygen and pH cycles in Kāne'ohe Bay, O'ahu, Hawai'i. Paired studies showed that algal mats reduced irradiance by 99% and doubled sediment accumulation. Several mats developed hypoxia and hyperoxia in the extreme minima and maxima, though there was no statistical difference detected in the mean or the variability of dissolved oxygen between different 30 min time points of 24 h cycles between algal mat-open reef pairs. The algal mat significantly acidified the water under the algal mat by decreasing pH by 0.10-0.13 pH units below open reef pH. A minimum of pH 7.47 occurred between 14 and 19 h after sunrise. Our combined results suggest that mats of G. salicornia can alter various physical parameters on a fine scale and time course not commonly detected. These changes in parameters give insight into the underlying basis for negative impact, and suggest new ways in which the presence of invasive species leads to decline of coral reef ecosystems.

  10. Methane Production by Microbial Mats Under Low Sulfate Concentrations

    Science.gov (United States)

    Bebout, Brad M.; Hoehler, Tori M.; Thamdrup, Bo; Albert, Dan; Carpenter, Steven P.; Hogan, Mary; Turk, Kendra; DesMarais, David J.

    2003-01-01

    Cyanobacterial mats collected in hypersaline salterns were incubated in a greenhouse under low sulfate concentrations ([SO4]) and examined for their primary productivity and emissions of methane and other major carbon species. Atmospheric greenhouse warming by gases such as carbon dioxide and methane must have been greater during the Archean than today in order to account for a record of moderate to warm paleoclemates, despite a less luminous early sun. It has been suggested that decreased levels of oxygen and sulfate in Archean oceans could have significantly stimulated microbial methanogenesis relative to present marine rates, with a resultant increase in the relative importance of methane in maintaining the early greenhouse. We maintained modern microbial mats, models of ancient coastal marine communities, in artificial brine mixtures containing both modern [SO4=] (ca. 70 mM) and "Archean" [SO4] (less than 0.2 mM). At low [SO4], primary production in the mats was essentially unaffected, while rates of sulfate reduction decreased by a factor of three, and methane fluxes increased by up to ten-fold. However, remineralization by methanogenesis still amounted to less than 0.4 % of the total carbon released by the mats. The relatively low efficiency of conversion of photosynthate to methane is suggested to reflect the particular geometry and chemical microenvironment of hypersaline cyanobacterial mats. Therefore, such mats w-ere probably relatively weak net sources of methane throughout their 3.5 Ga history, even during periods of low- environmental levels oxygen and sulfate.

  11. Cyanobacterial reuse of extracellular organic carbon in microbial mats.

    Science.gov (United States)

    Stuart, Rhona K; Mayali, Xavier; Lee, Jackson Z; Craig Everroad, R; Hwang, Mona; Bebout, Brad M; Weber, Peter K; Pett-Ridge, Jennifer; Thelen, Michael P

    2016-05-01

    Cyanobacterial organic matter excretion is crucial to carbon cycling in many microbial communities, but the nature and bioavailability of this C depend on unknown physiological functions. Cyanobacteria-dominated hypersaline laminated mats are a useful model ecosystem for the study of C flow in complex communities, as they use photosynthesis to sustain a more or less closed system. Although such mats have a large C reservoir in the extracellular polymeric substances (EPSs), the production and degradation of organic carbon is not well defined. To identify extracellular processes in cyanobacterial mats, we examined mats collected from Elkhorn Slough (ES) at Monterey Bay, California, for glycosyl and protein composition of the EPS. We found a prevalence of simple glucose polysaccharides containing either α or β (1,4) linkages, indicating distinct sources of glucose with differing enzymatic accessibility. Using proteomics, we identified cyanobacterial extracellular enzymes, and also detected activities that indicate a capacity for EPS degradation. In a less complex system, we characterized the EPS of a cyanobacterial isolate from ES, ESFC-1, and found the extracellular composition of biofilms produced by this unicyanobacterial culture were similar to that of natural mats. By tracing isotopically labeled EPS into single cells of ESFC-1, we demonstrated rapid incorporation of extracellular-derived carbon. Taken together, these results indicate cyanobacteria reuse excess organic carbon, constituting a dynamic pool of extracellular resources in these mats. PMID:26495994

  12. Reduction in photosynthetic efficiency of Cladophora glomerata, induced by overlying canopies of Lemna spp.

    Science.gov (United States)

    Parr, L B; Perkins, R G; Mason, C F

    2002-04-01

    The duckweeds Lemna minor L. and L. minuscula Herter reduced PSII quantum efficiency (F'q/F'm) of the filamentous green alga Cladophora glomerata Kützing by up to 42% over seven days when floating above mats of C. glomerata in containers. Dissolved oxygen (DO) increased by 23% at 30 degrees C in containers with C. glomerata over controls. But when the water surface in the containers was covered with Lemna spp. floating above C. glomerata, DO was 83% lower at 30 degrees C over seven days than in control samples with no duckweed or alga. Dissolved oxygen was lower beneath a thick mat (1 cm) of either Lemna spp. covering the surface than under a thin layer (single-frond canopy). PAM fluorimetry showed that maximum PSII efficiency (Fv/Fm) of C. glomerata in containers was reduced under a canopy of L. minor by 17% over seven days, and under L. minuscula by 22%. F'q/F'm of C. glomerata in containers exposed to 51 micromol m(-2) s(-1) PPFD decreased under a canopy of L. minor by 16% over seven days, and under L. minuscula by 19% compared to controls. When light response curves were compared, F'q/F'm was significantly reduced under canopies of L. minor at the highest temperatures tested (28 degrees C and 30 degrees C). L. minor significantly reduced relative electron transport rate (rel. ETR) of the controls by up to 71% at 30 degrees C. Relative electron transport rate did not reach light saturation point (Esat) except at 28 degrees and 30 degrees C under mats of L. minor. Whereas the highest rate of production (rel. ETRmax) and Esat increased with temperature in controls, under a canopy of Lemna, decreases were observed. It is suggested that, during periods of high summer temperature and irradiance, shading inhibits oxygenic photosynthesis in mats of C. glomerata beneath canopies of Lenma spp. This results in less oxygen being produced by the C. glomerata (oxygen produced by Lemna spp. is not released into the water), and this may further inhibit the C. glomerata by

  13. IAEA surveillance data administration within Mat-DB

    International Nuclear Information System (INIS)

    Full text: JRC-IE has developed a web-enabled materials database (Mat-DB) for storing materials test data resulting from international research projects together with other documentation in a related document management database (DoMa) providing fast access to confidential and public data sets. The databases are implemented in the secure ODIN portal: https://odin.jrc.ec.europa.eu of JRC-IE. Mat-DB covers thermo-mechanical and thermo-physical properties data of engineering alloys at low, elevated and high temperatures for base materials and joints, including irradiated materials for nu-clear fission and fusion applications, thermal barrier coated materials for gas turbines and properties of corroded materials. The corrosion part refers to weight gain/loss data of high temperature exposed engineering alloys and ceramic materials. For each test type the database structure reflects international test standards and recommendations. Mat-DB features an extensive library of evaluation programs for web-enabled assessment of uni-axial creep, fatigue, crack growth and high temperature corrosion properties. Evaluations can be performed after data retrieval or independently of Mat-DB by transferring other materials data in a given format to the programs. The fast evaluation processes help the user to get a detailed data analysis or data extrapolation for component design and life-time prediction. Within an bi-lateral agreement Mat-DB hosts also thousands IAEA surveillance data of reactor pressure vessel materials from different nuclear power plants of their member states. These tensile and impact materials data tested before and after irradiation are uploaded in a confidential area of Mat-DB only accessible for the entitled IAEA administrators. The paper provides an overview over: - reflection on the complexity of IAEA data transfer into Mat-DB; - implementation of standardized XML technology to ease complex data exchange in the future, - security, access rights and data

  14. Community Structure and Function of High-temperature Chlorophototrophic Microbial Mats Inhabiting Diverse Geothermal Environments

    Directory of Open Access Journals (Sweden)

    William P. Inskeep

    2013-06-01

    Full Text Available Six phototrophic microbial mat communities from different geothermal springs (YNP were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average~ 53 Mbp/site were subjected to multiple taxonomic, phylogenetic and functional analyses. All methods, including G+C content distribution, MEGAN analyses and oligonucleotide frequency-based clustering, provided strong support for the dominant community members present in each site. Cyanobacteria were only observed in non-sulfidic sites; de novo assemblies were obtained for Synechococcus-like populations at Chocolate Pots (CP_7 and Fischerella-like populations at White Creek (WC_6. Chloroflexi-like sequences (esp. Roseiflexus and/or Chloroflexus spp. were observed in all six samples and contained genes involved in bacteriochlorophyll biosynthesis and the 3-hydroxypropionate carbon fixation pathway. Other major sequence assemblies were obtained for a Chlorobiales population from CP_7 (proposed family Thermochlorobacteriaceae, and an anoxygenic, sulfur-oxidizing Thermochromatium-like (Gamma-proteobacteria population from Bath Lake Vista Annex (BLVA_20. Additional sequence coverage is necessary to establish more complete assemblies of other novel bacteria in these sites (e.g., Bacteroidetes and Firmicutes; however, current assemblies suggested that several of these organisms play important roles in heterotrophic and fermentative metabolisms. Definitive linkages were established between several of the dominant phylotypes present in these habitats and important functional

  15. Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe

    DEFF Research Database (Denmark)

    Willer, M; Hoffmann, Ulla-Lisbeth; Styrkársdóttir, U;

    1995-01-01

    The mat1 locus is a key regulator of both conjugation and meiosis in the fission yeast Schizosaccharomyces pombe. Two alternative DNA segments of this locus, mat1-P and mat1-M, specify the haploid cell types (Plus and Minus). Each segment includes two genes: mat1-P includes mat1-Pc and mat1-Pm......, while mat1-M includes mat1-Mc and mat1-Mm. The mat1-Pc and mat1-Mc genes are responsible for establishing the pheromone communication system that mediates conjugation between P and M cells, while all four mat1 genes are required for meiosis in diploid P/M cells. Our understanding of the initiation of...... meiosis is based largely on indirect observations, and a more precise investigation of these events was required to define the interaction between the mat1 genes. Here we resolve this issue using synthetic pheromones and P/M strains with mutations in either mat1-Pc or mat1-Mc. Our results suggest a model...

  16. Extraction of high molecular weight DNA from microbial mats.

    Science.gov (United States)

    Bey, Benjamin S; Fichot, Erin B; Norman, R Sean

    2011-01-01

    Successful and accurate analysis and interpretation of metagenomic data is dependent upon the efficient extraction of high-quality, high molecular weight (HMW) community DNA. However, environmental mat samples often pose difficulties to obtaining large concentrations of high-quality, HMW DNA. Hypersaline microbial mats contain high amounts of extracellular polymeric substances (EPS)1 and salts that may inhibit downstream applications of extracted DNA. Direct and harsh methods are often used in DNA extraction from refractory samples. These methods are typically used because the EPS in mats, an adhesive matrix, binds DNA during direct lysis. As a result of harsher extraction methods, DNA becomes fragmented into small sizes. The DNA thus becomes inappropriate for large-insert vector cloning. In order to circumvent these limitations, we report an improved methodology to extract HMW DNA of good quality and quantity from hypersaline microbial mats. We employed an indirect method involving the separation of microbial cells from the background mat matrix through blending and differential centrifugation. A combination of mechanical and chemical procedures was used to extract and purify DNA from the extracted microbial cells. Our protocol yields approximately 2 μg of HMW DNA (35-50 kb) per gram of mat sample, with an A(260/280) ratio of 1.6. Furthermore, amplification of 16S rRNA genes suggests that the protocol is able to minimize or eliminate any inhibitory effects of contaminants. Our results provide an appropriate methodology for the extraction of HMW DNA from microbial mats for functional metagenomic studies and may be applicable to other environmental samples from which DNA extraction is challenging. PMID:21775955

  17. Microcosm experiments of oil degradation by microbial mats

    International Nuclear Information System (INIS)

    Several microcosm experiments were run in parallel to evaluate the efficiency of microbial mats for crude oil degradation as compared with physico-chemical weathering. The oils used in the experiments constituted representative examples of those currently used for commercial purposes. One was aliphatic and of low viscosity (33.4 American Petroleum Institute degrees, o API) and the other was predominantly aromatic, with high sulphur content (ca. 2.7%) and viscosity (16.6o API). After crude oil introduction, the microcosms were kept under cyclic changes in water level to mimic coastal tidal movements. The transformations observed showed that water weathering leads to more effective and rapid elimination of low molecular weight hydrocarbons than microbial mat metabolism, e.g. n-alkanes with chain length shorter than n-pentadecane or n-heptadecane, regular isoprenoid hydrocarbons with chain length lower than C16 or C18 or lower molecular weight naphthalenes. Microbial mats preserved these hydrocarbons from volatilization and water washing. However, hydrocarbons of lower volatility such as the C24-C3 n-alkanes or containing nitrogen atoms, e.g. carbazoles, were eliminated in higher proportion by microbial mats than by water weathering. The strong differences in composition between the two oils used for the experiments were also reflected in significant differences between water weathering and microbial mat biodegradation. Higher oil viscosity seemed to hinder the former but not the later

  18. Microcosm experiments of oil degradation by microbial mats.

    Science.gov (United States)

    de Oteyza, Tirso García; Grimalt, Joan O; Llirós, Marc; Esteve, Isabel

    2006-03-15

    Several microcosm experiments were run in parallel to evaluate the efficiency of microbial mats for crude oil degradation as compared with physico-chemical weathering. The oils used in the experiments constituted representative examples of those currently used for commercial purposes. One was aliphatic and of low viscosity (33.4 American Petroleum Institute degrees, degrees API) and the other was predominantly aromatic, with high sulphur content (ca. 2.7%) and viscosity (16.6 degrees API). After crude oil introduction, the microcosms were kept under cyclic changes in water level to mimic coastal tidal movements. The transformations observed showed that water weathering leads to more effective and rapid elimination of low molecular weight hydrocarbons than microbial mat metabolism, e.g. n-alkanes with chain length shorter than n-pentadecane or n-heptadecane, regular isoprenoid hydrocarbons with chain length lower than C16 or C18 or lower molecular weight naphthalenes. Microbial mats preserved these hydrocarbons from volatilization and water washing. However, hydrocarbons of lower volatility such as the C24-C30 n-alkanes or containing nitrogen atoms, e.g. carbazoles, were eliminated in higher proportion by microbial mats than by water weathering. The strong differences in composition between the two oils used for the experiments were also reflected in significant differences between water weathering and microbial mat biodegradation. Higher oil viscosity seemed to hinder the former but not the later. PMID:15935450

  19. Thermomechanical analyses of phenolic foam reinforced with glass fiber mat

    International Nuclear Information System (INIS)

    Highlights: • Over 10% glass fiber was used to reinforce phenolic foam in the shape of glass fiber mat. • Nucleating agents were used together with glass fiber mat and improved tensile strength of phenolic foam by 215.6%. • Nucleating agents lead to a smaller bubble size of phenolic foam. • The glass transition temperature of phenolic foam remained unchanged during the reinforcement. - Abstract: In this paper, thermomechanical analysis (TMA) and dynamic mechanical analysis were employed to study the properties of phenolic foam reinforced with glass fiber mat. Unreinforced phenolic foam was taken as the control sample. Mechanical tests and scanning electron microscopy were performed to confirm the results of TMA. The results show that glass fiber mat reinforcement improves the mechanical performance of phenolic foam, and nucleating agents improve it further. Phenolic foam reinforced with glass fiber mat has a smaller thermal expansion coefficient compared with unreinforced foam. The storage modulus of the reinforced phenolic foam is also higher than that in unreinforced foam, whereas the loss modulus of the former is lower than that of the latter. The glass transition temperature of the phenolic foam matrix remains unchanged during the reinforcement

  20. Electrospun chitosan/polyvinyl alcohol nanofibre mats for wound healing.

    Science.gov (United States)

    Charernsriwilaiwat, Natthan; Rojanarata, Theerasak; Ngawhirunpat, Tanasait; Opanasopit, Praneet

    2014-04-01

    Chitosan (CS) aqueous salt blended with polyvinyl alcohol (PVA) nanofibre mats was prepared by electrospinning. CS was dissolved with hydroxybenzotriazole (HOBt), thiamine pyrophosphate (TPP) and ethylenediaminetetraacetic acid (EDTA) in distilled water without the use of toxic or hazardous solvents. The CS aqueous salts were blended with PVA at different weight ratios, and the effect of the solution ratios was investigated. The morphologies and mechanical and swelling properties of the generated fibres were analysed. Indirect cytotoxicity studies indicated that the CS/PVA nanofibre mats were non-toxic to normal human fibroblast cells. The CS-HOBt/PVA and CS-EDTA/PVA nanofibre mats demonstrated satisfactory antibacterial activity against both gram-positive and gram-negative bacteria, and an in vivo wound healing test showed that the CS-EDTA/PVA nanofibre mats performed better than gauze in decreasing acute wound size during the first week after tissue damage. In conclusion, the biodegradable, biocompatible and antibacterial CS-EDTA/PVA nanofibre mats have potential for use as wound dressing materials. PMID:22925275

  1. Rickettsia spp. in Ticks, Poland

    OpenAIRE

    Chmielewski, Tomasz; Podsiadly, Edyta; Karbowiak, Grzegorz; Tylewska-Wierzbanowska, Stanislawa

    2009-01-01

    Ticks are recognized as the main vectors and reservoirs of spotted fever group rickettsiae. We searched for the most prevalent Rickettsia spp. in Poland and found R. slovaca and R. helvetica bacteria in ticks in southern and central Poland; R. raoulti was found in ticks in all parts of Poland.

  2. Sistem Informari Pembayaran Spp Di Sma Lhokseumawe

    OpenAIRE

    Gunwan, M. Arif

    2013-01-01

    Kajian ini bertujuan untuk membangun suatu sistem informasi pembayaran spp. Sistem ini dikembangkan dengan menggunakan perangkat lunak Microsoft Visual Basic 6.0 dan Microsoft Access 2003. Sistem ini bekerja untuk dapat memasukkan data siswa,data kelas, dan transaksi pembayaran biaya pendidikan, seperti spp. Tujuan sistem ini adalah untuk mempermudah bendahara dalam melakukan transaksi pembayaran spp. 092406156

  3. Survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Anahí Souto Vieira

    2011-09-01

    Full Text Available This work reports a survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction (PCR. Seventy pampas deer were captured in the dry season and surveyed using PCR, microscopic agglutination test (MAT (n = 51 and by both techniques (n = 47. PCR detected infections in two pampas deer and MAT detected infections in three. Through sequencing and phylogenetic analyses, the PCR-amplified fragment detected in deer was identified as Leptospira interrogans. Serovars Pomona and Butembo were detected using MAT and the highest titre was 200 for serovar Pomona. Epidemiological aspects of the findings are discussed.

  4. Pressure Mapping Mat for Tele-Home Care Applications

    Science.gov (United States)

    Saenz-Cogollo, Jose Francisco; Pau, Massimiliano; Fraboni, Beatrice; Bonfiglio, Annalisa

    2016-01-01

    In this paper we present the development of a mat-like pressure mapping system based on a single layer textile sensor and intended to be used in home environments for monitoring the physical condition of persons with limited mobility. The sensor is fabricated by embroidering silver-coated yarns on a light cotton fabric and creating pressure-sensitive resistive elements by stamping the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) at the crossing points of conductive stitches. A battery-operated mat prototype was developed and includes the scanning circuitry and a wireless communication module. A functional description of the system is presented together with a preliminary experimental evaluation of the mat prototype in the extraction of plantar pressure parameters. PMID:26978369

  5. HiRadMat High Intensity Beam Commissioning

    CERN Document Server

    Blanco Sancho, J; Cornelis, K; Goddard, B; Hessler, C; Jensen, L; Kain, V; Meddahi, M; Theis, C; Vincke, H; Vojtyla, P; Wenninger, J

    2011-01-01

    On Wednesday 14 September and Monday 19 September 2011, high intensity proton beam was sent for the first time down the HiRadMat primary beam line (thereafter TT66), onto the beam dump located in the HiRadMat experimental cavern. This high intensity beam commissioning followed a first period of low intensity beam commissioning which took place in June 2011. During the low intensity beam commissioning, it was checked that all beam line equipment operated as specified. Energy matching and beam steering were performed; optics checks did not reveal any optical errors. Aperture measurements confirmed that there were no bottlenecks. Radiation protection monitoring worked as expected and the measurements were within expectation [1]. With the completion of the HiRadMat ventilation system, the high intensity beam commissioning could successfully continue in September 2011. The main outcome is reported in this note.

  6. NANOFIBROUS MATS WITH BIRD'S NEST PATTERNS BY ELECTROSPINNING

    Institute of Scientific and Technical Information of China (English)

    Xiang-yu Ye; Xiao-jun Huang; Zhi-kang Xu

    2012-01-01

    Electrospun material with bio-inspired ordered architectures and patterns is very interesting,yet remains a challenge.We report here that nanofibrous mats with bird's nest patterned structures can be directly electrospun from chlorinated polypropylene solutions doped with an ionic liquid.The solution viscosity and the ionic liquid content are two dominant factors to influence the lopological morphology of the nanofibrous mats.The patterned structures can be further modulated by the collection time of electrospinning,the humidity of environment and the design of collector.We suggest the electrostatic repulsion between the residual charges of the mat surface and the upcoming nanofibers plays a key role in the formation of the bird's nest patterns.

  7. Storage of yerba maté in controlled atmosphere

    Directory of Open Access Journals (Sweden)

    Sarah Lemos Cogo Prestes

    2014-04-01

    Full Text Available The aim of this study was to evaluate the effect of controlled atmosphere in the change of color, chlorophyll degradation and phenolic compounds concentration in yerba maté thickly ground (“cancheada” and thinly milled (“socada”. Yerba maté samples from the towns of Arvorezinha (RS - Brazil and São Mateus do Sul (PR - Brazil were stored in four levels of oxygen (1, 3, 6 and 20.9kPa of O2 and four levels of carbon dioxide (0, 3, 6 and 18kPa of CO2 and then were analyzed, after nine months of storage. According to the results, the O2 partial pressure reduction decreased the loss of green coloration, kept a higher content of chlorophylls and of total phenolic compounds. In relation to the different levels of CO2, a response as remarkable as O2 was not observed. The yerba maté that was thickly ground (“cancheada” presented a better storage potential than the one thinly milled (“socada” in the storage with O2 and with CO2. The 1kPa of O2 condition kept the yerba maté greener and with a higher content of chlorophylls and of total phenolic compounds after nine months of storage. The CO2 partial pressure kept the yerba maté coloration greener and with a higher content of chlorophylls and of total phenolic compounds, regardless of the level used, in the maté from both cultivation areas.

  8. The Extracellular Matrix in Photosynthetic Mats: A Cyanobacterial Gingerbread House

    Science.gov (United States)

    Stuart, R.; Stannard, W.; Bebout, B.; Pett-Ridge, J.; Mayali, X.; Weber, P. K.; Lipton, M. S.; Lee, J.; Everroad, R. C.; Thelen, M.

    2014-12-01

    Hypersaline laminated cyanobacterial mats are excellent model systems for investigating photoautotrophic contributions to biogeochemical cycling on a millimeter scale. These self-sustaining ecosystems are characterized by steep physiochemical gradients that fluctuate dramatically on hour timescales, providing a dynamic environment to study microbial response. However, elucidating the distribution of energy from light absorption into biomass requires a complete understanding of the various constituents of the mat. Extracellular polymeric substances (EPS), which can be composed of proteins, polysaccharides, lipids and DNA are a major component of these mats and may function in the redistribution of nutrients and metabolites within the community. To test this notion, we established a model mat-building culture for comparison with the phylogenetically diverse natural mat communities. In these two systems we determined how proteins and glycans in the matrix changed as a function of light and tracked nutrient flow from the matrix. Using mass spectrometry metaproteomics analysis, we found homologous proteins in both field and culture extracellular matrix that point to cyanobacterial turnover of amino acids, inorganic nutrients, carbohydrates and nucleic acids from the EPS. Other abundant functions identified included oxidative stress response from both the cyanobacteria and heterotrophs and cyanobacterial structural proteins that may play a role in mat cohesion. Several degradative enzymes also varied in abundance in the EPS in response to light availability, suggesting active secretion. To further test cyanobacterial EPS turnover, we generated isotopically-labeled EPS and used NanoSIMS to trace uptake of this labeled EPS. Our findings suggest Cyanobacteria may facilitate nutrient transfer to other groups, as well as uptake of their own products through degradation of EPS components. This work provides evidence for the essential roles of EPS for storage, structural

  9. The heterothallic sugarbeet pathogen Cercospora beticola contains exon fragments of both MAT genes that are homogenized by concerted evolution

    NARCIS (Netherlands)

    Bolton, M.D.; Jonge, de R.; Inderbitzin, P.; Liu, Z.; Birla, K.; Peer, Van de Y.; Subbarao, K.; Thomma, B.P.H.J.; Secor, G.

    2014-01-01

    Dothideomycetes is one of the most ecologically diverse and economically important classes of fungi. Sexual reproduction in this group is governed by mating type (MAT) genes at the MAT1 locus. Self-sterile (heterothallic) species contain one of two genes at MAT1 (MAT1-1-1 or MAT1-2-1) and only isola

  10. Flow of light energy in benthic photosynthetic microbial mats

    Energy Technology Data Exchange (ETDEWEB)

    Al-Najjar, Mohammad Ahmad A.

    2010-12-15

    The work in this thesis demonstrates the assessment of the energy budget inside microbial mat ecosystems, and the factors affecting light utilization efficiency. It presents the first balanced light energy budget for benthic microbial mat ecosystems, and shows how the budget and the spatial distribution of the local photosynthetic efficiencies within the euphotic zone depend on the absorbed irradiance (Jabs). The energy budget was dominated by heat dissipation on the expense of photosynthesis. The maximum efficiency of photosynthesis was at light limiting conditions When comparing three different marine benthic photosynthetic ecosystems (originated from Abu-Dhabi, Arctic, and Exmouth Gulf in Western Australia), differences in the efficiencies were calculated. The results demonstrated that the maximum efficiency depended on mat characteristics affecting light absorption and scattering; such as, photopigments ratio and distribution, and the structural organization of the photosynthetic organisms relative to other absorbing components of the ecosystem (i.e., EPS, mineral particles, detritus, etc.). The maximum efficiency decreased with increasing light penetration depth, and increased with increasing the accessory pigments (phycocyanin and fucoxanthin)/chlorophyll ratio. Spatial heterogeneity in photosynthetic efficiency, pigment distribution, as well as light acclimation in microbial mats originating from different geographical locations was investigated. We used a combined pigment imaging approach (variable chlorophyll fluorescence and hyperspectral imaging), and fingerprinting approach. For each mat, the photosynthetic activity was proportional to the local pigment concentration in the photic zone, but not for the deeper layers and between different mats. In each mat, yield of PSII and E1/2 (light acclimation) generally decreased in parallel with depth, but the gradients in both parameters varied greatly between samples. This mismatch between pigments concentration

  11. HiRadMat Low Intensity Beam Commissioning

    CERN Document Server

    Blanco Sancho, J; Cornelis, K; Goddard, B; Hessler, C; Jensen, L; Kain, V; Meddahi, M; Theis, C; Vojtyla, P; Wenninger, J

    2011-01-01

    On Wednesday 22 June 2011, proton beam was sent for the first time through the HiRadMat primary beam line, onto the beam dump located in the HiRadMat experimental cavern. The aims of the beam commissioning were to check the beam line geometry and design validity, the correct functioning of all beam line equipment and to verify the beam parameters. At the first trial, the proton beam reached the end of the primary beam line and the preliminary checks allowed confirming that all beam equipment and parameters are within the specification.

  12. Radon and thoron anomalies along Mat fault in Mizoram, India

    Science.gov (United States)

    Jaishi, Hari Prasad; Singh, Sanjay; Tiwari, Raghavendra Prasad; Tiwari, Ramesh Chandra

    2013-12-01

    In this study, radon and thoron concentrations in soil gas has been monitored using LR-115(II) solid state nuclear track detectors since 15th July 2011 to February 2012. The study was carried out along Mat fault in Serchip district, Mizoram, India at two different sites - Mat Bridge (23°18'N, 92°48'E) and Tuichang (23°13'N, 92°56'E). The results obtained have been correlated to the seismic events that occurred within 800 km from the measuring sites over the mentioned period of time. Anomalous behaviour in radon concentrations have been observed prior to some earthquakes. Interestingly, some thoron anomalies were also recorded.

  13. Grazing effects by Nereis diversicolor on development and growth of green algal mats

    Science.gov (United States)

    Engelsen, Anna; Pihl, Leif

    2008-08-01

    Nereis diversicolor is generally considered to be a predator and deposit feeder, but have also been found to graze on benthic algae in shallow coastal areas. In this study we investigated the grazing effects on the development and growth of green algae, Ulva spp. Algal growth was studied in an experiment including two levels of sediment thickness; 100 mm sediment including macrofauna and 5 mm sediment without macrofauna, and three treatments of varying algal biomass; sediment with propagules, sediment with low algal biomass (120 g dry weight (dwt) m - 2 ) and sediment with high algal biomass (240 g dwt m - 2 ). In the 100 mm sediment, with a natural population of macrofauna, N. diversicolor was the dominating (60% of total biomass) species. After three weeks of experimentation the result showed that N. diversicolor was able to prevent initial algal growth, affect growth capacity and also partly reduce full-grown algal mats. The weight of N. diversicolor was significantly higher for polychaetes in treatments with algae added compared to non-algal treatments. There were also indications that a rich nutrient supply per algae biomass counteracted the grazing capacity of N. diversicolor.

  14. Genetic engineering of Geobacillus spp.

    Science.gov (United States)

    Kananavičiūtė, Rūta; Čitavičius, Donaldas

    2015-04-01

    Members of the genus Geobacillus are thermophiles that are of great biotechnological importance, since they are sources of many thermostable enzymes. Because of their metabolic versatility, geobacilli can be used as whole-cell catalysts in processes such as bioconversion and bioremediation. The effective employment of Geobacillus spp. requires the development of reliable methods for genetic engineering of these bacteria. Currently, genetic manipulation tools and protocols are under rapid development. However, there are several convenient cloning vectors, some of which replicate autonomously, while others are suitable for the genetic modification of chromosomal genes. Gene expression systems are also intensively studied. Combining these tools together with proper techniques for DNA transfer, some Geobacillus strains were shown to be valuable producers of recombinant proteins and industrially important biochemicals, such as ethanol or isobutanol. This review encompasses the progress made in the genetic engineering of Geobacillus spp. and surveys the vectors and transformation methods that are available for this genus. PMID:25659824

  15. Bioremediation of hexavalent chromium by a cyanobacterial mat

    Science.gov (United States)

    Shukla, Dhara; Vankar, Padma S.; Srivastava, Sarvesh Kumar

    2012-12-01

    The study comprises the use of cyanobacterial mat (collected from tannery effluent site) to remove hexavalent chromium. This mat was consortium of cyanobacteria/blue-green algae such as Chlorella sp., Phormidium sp. and Oscillatoria sp. The adsorption experiments were carried out in batches using chromium concentrations 2-10, 15-30 and 300 ppm at pH 5.5-6.2. The adsorption started within 15 min; however, 96 % reduction in metal concentration was observed within 210 min. The adsorption phenomenon was confirmed by Fourier transform-infrared spectroscopy and energy dispersive X-ray analysis. This biosorption fitted Freundlich adsorption isotherm very well. It was observed that the best adsorption was at 4 ppm, and at 25 ppm in the chosen concentration ranges. Scanning electron micrograph showed the physiology of mat, indicating sites for metal uptake. The main focus was collection of the cyanobacterial mat from local environments and its chromium removal potential at pH 5.5-6.2.

  16. The Varian MAT-250 mass spectrometer. Steady isotopes laboratory

    International Nuclear Information System (INIS)

    This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, δ notation. (Author)

  17. Myocardial Cell Pattern on Piezoelectric Nanofiber Mats for Energy Harvesting

    International Nuclear Information System (INIS)

    The paper presents in vitro contractile myocardial cell pattern on piezoelectric nanofiber mats with applications in energy harvesting. The cell-based energy harvester consists of myocardial cell sheet and a PDMS substrate with a PVDF nanofiber mat on. Experimentally, cultured on specifically distributed nanofiber mats, neonatal rat ventricular cardiomyocytes are characterized with the related morphology and contraction. Previously, we have come up with the concept of energy harvesting from heart beating using piezoelectric material. A bio-hybrid energy harvester combined living cardiomyocytes, PDMS polymer substrate and piezoelectric PVDF film with the electrical output of peak current 87.5nA and peak voltage 92.3mV. However, the thickness of the cardiomyocyte cultured on a two-dimensional substrate is much less than that of the piezoelectric film. The Micro Contact Printing (μCP) method used in cell pattern on the PDMS thin film has tough requirement for the film surface. As such, in this paper we fabricated nanofiber-constructed PDMS thin film to realize cell pattern due to PVDF nanofibers with better piezoelectricity and microstructures of nanofiber mats guiding cell distribution. Living cardiomyocytes patterned on those distributed piezoelectric nanofibers with the result of the same distribution as the nanofiber pattern

  18. Nitrification and Nitrifying Bacteria in a Coastal Microbial Mat

    NARCIS (Netherlands)

    H. Fan; H. Bolhuis; L.J. Stal

    2015-01-01

    The first step of nitrification, the oxidation of ammonia to nitrite, can be performed by ammonia-oxidizing archaea (AOA) or ammonium-oxidizing bacteria (AOB). We investigated the presence of these two groups in three structurally different types of coastal microbial mats that develop along the tida

  19. The Dark Side of the Mushroom Spring Microbial Mat: Life in the Shadow of Chlorophototrophs. I. Microbial Diversity Based on 16S rRNA Gene Amplicons and Metagenomic Sequencing.

    Science.gov (United States)

    Thiel, Vera; Wood, Jason M; Olsen, Millie T; Tank, Marcus; Klatt, Christian G; Ward, David M; Bryant, Donald A

    2016-01-01

    Microbial-mat communities in the effluent channels of Octopus and Mushroom Springs within the Lower Geyser Basin at Yellowstone National Park have been studied for nearly 50 years. The emphasis has mostly focused on the chlorophototrophic bacterial organisms of the phyla Cyanobacteria and Chloroflexi. In contrast, the diversity and metabolic functions of the heterotrophic community in the microoxic/anoxic region of the mat are not well understood. In this study we analyzed the orange-colored undermat of the microbial community of Mushroom Spring using metagenomic and rRNA-amplicon (iTag) analyses. Our analyses disclosed a highly diverse community exhibiting a high degree of unevenness, strongly dominated by a single taxon, the filamentous anoxygenic phototroph, Roseiflexus spp. The second most abundant organisms belonged to the Thermotogae, which have been hypothesized to be a major source of H2 from fermentation that could enable photomixotrophic metabolism by Chloroflexus and Roseiflexus spp. Other abundant organisms include two members of the Armatimonadetes (OP10); Thermocrinis sp.; and phototrophic and heterotrophic members of the Chloroflexi. Further, an Atribacteria (OP9/JS1) member; a sulfate-reducing Thermodesulfovibrio sp.; a Planctomycetes member; a member of the EM3 group tentatively affiliated with the Thermotogae, as well as a putative member of the Arminicenantes (OP8) represented ≥1% of the reads. Archaea were not abundant in the iTag analysis, and no metagenomic bin representing an archaeon was identified. A high microdiversity of 16S rRNA gene sequences was identified for the dominant taxon, Roseiflexus spp. Previous studies demonstrated that highly similar Synechococcus variants in the upper layer of the mats represent ecological species populations with specific ecological adaptations. This study suggests that similar putative ecotypes specifically adapted to different niches occur within the undermat community, particularly for Roseiflexus

  20. The Dark Side of the Mushroom Spring Microbial Mat: Life in the Shadow of Chlorophototrophs. I. Microbial Diversity Based on 16S rRNA Gene Amplicons and Metagenomic Sequencing

    Science.gov (United States)

    Thiel, Vera; Wood, Jason M.; Olsen, Millie T.; Tank, Marcus; Klatt, Christian G.; Ward, David M.; Bryant, Donald A.

    2016-01-01

    Microbial-mat communities in the effluent channels of Octopus and Mushroom Springs within the Lower Geyser Basin at Yellowstone National Park have been studied for nearly 50 years. The emphasis has mostly focused on the chlorophototrophic bacterial organisms of the phyla Cyanobacteria and Chloroflexi. In contrast, the diversity and metabolic functions of the heterotrophic community in the microoxic/anoxic region of the mat are not well understood. In this study we analyzed the orange-colored undermat of the microbial community of Mushroom Spring using metagenomic and rRNA-amplicon (iTag) analyses. Our analyses disclosed a highly diverse community exhibiting a high degree of unevenness, strongly dominated by a single taxon, the filamentous anoxygenic phototroph, Roseiflexus spp. The second most abundant organisms belonged to the Thermotogae, which have been hypothesized to be a major source of H2 from fermentation that could enable photomixotrophic metabolism by Chloroflexus and Roseiflexus spp. Other abundant organisms include two members of the Armatimonadetes (OP10); Thermocrinis sp.; and phototrophic and heterotrophic members of the Chloroflexi. Further, an Atribacteria (OP9/JS1) member; a sulfate-reducing Thermodesulfovibrio sp.; a Planctomycetes member; a member of the EM3 group tentatively affiliated with the Thermotogae, as well as a putative member of the Arminicenantes (OP8) represented ≥1% of the reads. Archaea were not abundant in the iTag analysis, and no metagenomic bin representing an archaeon was identified. A high microdiversity of 16S rRNA gene sequences was identified for the dominant taxon, Roseiflexus spp. Previous studies demonstrated that highly similar Synechococcus variants in the upper layer of the mats represent ecological species populations with specific ecological adaptations. This study suggests that similar putative ecotypes specifically adapted to different niches occur within the undermat community, particularly for Roseiflexus

  1. Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

    OpenAIRE

    Lee, Jackson Z.; Burow, Luke C; Dagmar eWoebken; R Craig Everroad; Kubo, Michael D.; Alfred Michael Spormann; Weber, Peter K.; Jennifer ePett-Ridge; Bebout, Brad M; Hoehler, Tori M.

    2014-01-01

    Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB). However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico -- permanently submerged Microcoleus microbial mats (GN-S), and intertidal Lyngbya microbial mats (GN-I) -- were used in microcosm diel manipulation experiments wi...

  2. Preparation of PVA/ H3PW12O40 Fiber Mats

    Institute of Scientific and Technical Information of China (English)

    Jian GONG; Chang Lu SHAO; Guo Cheng YANG; Yan PAN; Lun Yu QU

    2004-01-01

    Poly(vinyl alcohol) (PVA) fiber mats containing 20 and 80 wt% H3PW12O40 were prepared by using electrospinning technique. The fiber mats were characterized by IR, XRD spectra and scanning electron microscope (SEM). The diameter of the fiber mats is ca. 400 nm.

  3. Aspects of the ecology of mat-forming lichens

    Directory of Open Access Journals (Sweden)

    P. D. Crittenden

    2000-03-01

    Full Text Available Lichen species in the genera Cladonia (subgenus Cladina, Cetraria, Stereocaulon and Alectoria are important vegetation components on well-drained terrain and on elevated micro-sites in peatlands in boreal-Arctic regions. These lichens often form closed mats, the component thalli in which grow vertically upwards at the apices and die off in the older basal regions; they are therefore only loosely attached to the underlying soil. This growth habit is relatively unusual in lichens being found in <0.5% of known species. It might facilitate internal nutrienr recycling and higher growth rates and, together with the production of allelochemicals, it might underlie the considerable ecological success of mat-forming lichens; experiments to critically assess the importance of these processes are required. Mat-forming lichens can constitute in excess of 60% of the winter food intake of caribou and reindeer. Accordingly there is a pressing need for data on lichen growth rates, measured as mass increment, in order to help determine the carrying capacity of winter ranges for rhese herbivores and to better predict recovery rates following grazing. Trampling during the snow-free season fragments lichen thalli; mat-forming lichens regenerate very successfully from thallus fragments provided trampling does nor re-occur. Frequent recurrence of trampling creates disturbed habitats from which lichens will rapidly become eliminated consistent with J.P. Grime's CSR strategy theory. Such damage to lichen ground cover has occurred where reindeer or caribou are unable to migrate away from their winter range such as on small islands or where political boundaries have been fenced; it can also occur on summer range that contains a significant lichen component and on winter range where numbers of migrarory animals become excessive. Species of Stereocaulon, and other genera that contain cyanobacteria (most notably Peltigera and Nephroma, are among the principal agents of

  4. New plate medium for facilitated differentiation of Salmonella spp. from Proteus spp. and other enteric bacteria.

    OpenAIRE

    Rambach, A

    1990-01-01

    A new agar medium for the differentiation of Salmonella spp. from other members of the family Enterobacteriaceae is described. This medium exploits a novel phenotypic characteristic of Salmonella spp.: the formation of acid from propylene glycol. This characteristic may be used in combination with a chromogenic indicator of beta-galactosidase to differentiate Salmonella spp. from Proteus spp. and the other members of the Enterobacteriaceae. Desoxycholate may be included in the plate medium as...

  5. DETECTION OF Leptospira spp. AND Brucella abortus ANTIBODIES IN FREE-LIVING JAGUARS (Panthera onca IN TWO PROTECTED AREAS OF NORTHERN PANTANAL, BRAZIL

    Directory of Open Access Journals (Sweden)

    Selma Samiko Miyazaki ONUMA

    2015-04-01

    Full Text Available This study aimed to assess the exposure of free-living jaguars (Panthera onca to Leptospira spp. and Brucella abortus in two conservation units in the Pantanal of Mato Grosso, Brazil. The presence of antibodies in blood samples of eleven jaguars was investigated using autochthonous antigens isolated in Brazil added to reference antigen collection applied to diagnosis of leptospirosis by Microscopic Agglutination Test (MAT. The Rose Bengal test was applied for B. abortus antibodies. Two (18.2% jaguars were seroreactive for the Leptospira spp. antigen and the serovar considered as most infective in both animals was a Brazilian isolate of serovar Canicola (L01. All jaguars were seronegative for B. abortus. These data indicate that the inclusion of autochthonous antigens in serological studies can significantly increase the number of reactive animals, as well as modify the epidemiological profile of Leptospira spp. infection.

  6. Frequency of Leptospira spp. in sheep from Brazilian slaughterhouses and its association with epidemiological variables

    Directory of Open Access Journals (Sweden)

    Rodrigo Costa da Silva

    2012-03-01

    Full Text Available Leptospirosis is a worldwide anthropozoonosis that infects livestock, including sheep as the carriers to other animals and humans. The present study aimed to determine the prevalence of Leptospira spp. in sheep from two slaughterhouses in the state of São Paulo, Brazil and its association with epidemiological variables. Serum samples from 182 sheep were evaluated for Leptospira spp. antibodies by microscopic agglutination test (MAT. Results indicated 34/182 (18.68%; CI95% 13.70-24.98% positive serum samples, mainly to the serovar Copenhageni (17/34; 50%; CI95% 33.99-66.01%. Bacterial growth in the Fletcher medium was detected for 13/34 (38.24%; CI95% 23.87-55.08% animals, and confirmed by Polymerase Chain Reaction (PCR and sequencing for only two kidney samples from two animals. Thus, treatment and vaccination of sheep, besides rodent control, can be useful to prevent the infection in the studied region since sheep are important Leptospira spp. carriers, and its transmission to slaughterhouse workers is mainly through the manipulation of visceral tissues.

  7. Promoção do crescimento do feijoeiro e controle da antracnose por Trichoderma spp Plant growth promotion of common bean and anthracnose control by Trichoderma spp

    Directory of Open Access Journals (Sweden)

    Erica Aparecida de Souza Pedro

    2012-11-01

    Full Text Available O objetivo deste trabalho foi avaliar a capacidade de Trichoderma spp. em promover o crescimento de plantas de feijão e reduzir a severidade da antracnose do feijoeiro (Colletotrichum lindemuthianum, bem como identificar os isolados mais eficientes. Sessenta isolados de Trichoderma spp. foram avaliados quanto à capacidade de promoção do crescimento nas plantas. Os sete isolados que mais se destacaram foram adicionados ao substrato de cultivo e avaliados quanto à redução na severidade da antracnose em plantas de feijão tratadas com conídios de C. lindemuthianum. Os mais eficientes no controle da doença foram identificados por sequenciamento de DNA. O isolado IB 28/07 foi avaliado nas concentrações 0,5, 1, 1,5 e 2% (peso:volume, que reduziram a severidade da doença em 41,51, 55,15, 81,82 e 96,06%, respectivamente. Os isolados mais eficientes de Trichoderma spp. podem proporcionar aumentos superiores a 30% na produção de matéria seca da parte aérea das plantas e reduzir a severidade da doença entre 63 e 98%. Esses isolados foram identificados como pertencentes às espécies Trichoderma harzianum, T. strigosum e T. theobromicola.The objective of this work was to evaluate the ability of Trichoderma spp. to promote growth of common bean plants and to reduce severity of anthracnose (Colletotrichum lindemuthianum, as well as to identify the best performing isolates. Sixty Trichoderma spp. isolates were evaluated as to their capacity to promote growth in common bean. The seven isolates that stood out were added to the culture substrate and assessed for reduction in severity of anthracnose in bean plants treated with C. lindemuthianum conidia. The most efficient isolates in controlling the disease were identified by DNA sequencing. The IB 28/07 isolate was evaluated in the concentrations 0.5, 1, 1.5, and 2% (weight:volume, which reduced disease severity in 41.51, 55.15, 81.82, and 96.06%, respectively. The most efficient Trichoderma spp

  8. Radon and thoron anomalies along Mat fault in Mizoram, India

    Indian Academy of Sciences (India)

    Hari Prasad Jaishi; Sanjay Singh; Raghavendra Prasad Tiwari; Ramesh Chandra Tiwari

    2013-12-01

    In this study, radon and thoron concentrations in soil gas has been monitored using LR-115(II) solid state nuclear track detectors since 15th July 2011 to February 2012. The study was carried out along Mat fault in Serchip district, Mizoram, India at two different sites – Mat Bridge (23°18′N, 92° 48′E) and Tuichang (23° 13′N, 92° 56′E). The results obtained have been correlated to the seismic events that occurred within 800km from the measuring sites over the mentioned period of time. Anomalous behaviour in radon concentrations have been observed prior to some earthquakes. Interestingly, some thoron anomalies were also recorded.

  9. Social yoga mats: reinforcing synergy between physical and social activity

    DEFF Research Database (Denmark)

    Nagargoje, Arun; Sokoler, Tomas; Maybach, Karl

    2011-01-01

    This paper discusses our early research into the design space for digital technologies that extend the existing synergistic relationship between physical and social activity from fitness centers to the home. We focus on yoga activity for senior citizens and explore the concept of social yoga mats......, which spread awareness of individuals' exercise activities within a peer group. We describe the concept, hardware sketches, exploratory co-design process and discuss our findings and early reflections into this design space.......This paper discusses our early research into the design space for digital technologies that extend the existing synergistic relationship between physical and social activity from fitness centers to the home. We focus on yoga activity for senior citizens and explore the concept of social yoga mats...

  10. Biogeochemical cycles of carbon, sulfur, and free oxygen in a microbial mat

    Science.gov (United States)

    Canfield, Donald E.; Des Marais, David J.

    1993-01-01

    Complete budgets for carbon and oxygen have been constructed for cyanobacterial mats dominated by Microcoleus chthonoplastes from the evaporating ponds of a salt works. We infer from the data the various sinks for O2 as well as the sources of carbon for primary production. Although seasonal variability exists, a major percentage of the O2 produced during the day did not diffuse out of the mat but was used within the mat to oxidize both organic carbon and the sulfide produced by sulfate reduction. At night, most of the O2 that diffused into the mat was used to oxidize sulfide, with O2 respiration of minor importance. During the day, the internal mat processes of sulfate reduction and O2 respiration generated as much or more inorganic carbon (DIC) for primary production as diffusion into the mat. Oxygenic photosynthesis was the most important process of carbon fixation. At night, the DIC lost from the mat was mostly from sulfate reduction. Elemental fluxes across the mat/brine interface indicated that carbon with an oxidation state of greater than zero was taken up by the mat during the day and liberated from the mat at night. Overall, carbon with an average oxidation state of near zero accumulated in the mat. Both carbon fixation and carbon oxidation rates varied with temperature by a similar amount.

  11. Nitrification and Nitrifying Bacteria in a Coastal Microbial Mat

    OpenAIRE

    Fan, Haoxin; Bolhuis, Henk; Stal, Lucas J.

    2015-01-01

    The first step of nitrification, the oxidation of ammonia to nitrite, can be performed by ammonia-oxidizing archaea (AOA) or ammonium-oxidizing bacteria (AOB). We investigated the presence of these two groups in three structurally different types of coastal microbial mats that develop along the tidal gradient on the North Sea beach of the Dutch barrier island Schiermonnikoog. The abundance and transcription of amoA, a gene encoding for the alpha subunit of ammonia monooxygenase that is presen...

  12. NITRIFICATION AND NITRIFYING BACTERIA IN A COASTAL MICROBIAL MAT

    OpenAIRE

    Haoxin eFan; Henk eBolhuis; Lucas eStal

    2015-01-01

    The first step of nitrification, the oxidation of ammonia to nitrite, can be performed by ammonia-oxidizing archaea (AOA) or ammonium-oxidizing bacteria (AOB). We investigated the presence of these two groups in three structurally different types of coastal microbial mats that develop along the tidal gradient on the North Sea beach of the Dutch barrier island Schiermonnikoog. The abundance and transcription of amoA, a gene encoding for the alpha subunit of ammonia monooxygenase that is presen...

  13. Mineralogy of iron microbial mats from loihi seamount.

    Science.gov (United States)

    Toner, Brandy M; Berquó, Thelma S; Michel, F Marc; Sorensen, Jeffry V; Templeton, Alexis S; Edwards, Katrina J

    2012-01-01

    Extensive mats of Fe oxyhydroxides and associated Fe-oxidizing microbial organisms form in diverse geochemical settings - freshwater seeps to deep-sea vents - where ever opposing Fe(II)-oxygen gradients prevail. The mineralogy, reactivity, and structural transformations of Fe oxyhydroxides precipitated from submarine hydrothermal fluids within microbial mats remains elusive in active and fossil systems. In response, a study of Fe microbial mat formation at the Loihi Seamount was conducted to describe the physical and chemical characteristics of Fe-phases using extended X-ray absorption fine structure spectroscopy, powder X-ray diffraction, synchrotron radiation X-ray total scattering, low-temperature magnetic measurements, and Mössbauer spectroscopy. Particle sizes of 3.5-4.6 nm were estimated from magnetism data, and coherent scattering domain (CSD) sizes as small as 1.6 nm are indicated by pair distribution function (PDF) analysis. Disorder in the nanostructured Fe-bearing phases results in limited intermediate-range structural order: less than that of standard two-line ferrihydrite (Fh), except for the Pohaku site. The short-range ordered natural Fh (Fh(SRO)) phases were stable at 4°C in the presence of oxygen for at least 1 year and during 400°C treatment. The observed stability of the Fh(SRO) is consistent with magnetic observations that point to non-interacting nanoparticles. PDF analyses of total scattering data provide further evidence for Fh(SRO) particles with a poorly ordered silica coating. The presence of coated particles explains the small CSD for the mat minerals, as well as the stability of the minerals over time and against heating. The mineral properties observed here provide a starting point from which progressively older and more extensively altered Fe deposits may be examined, with the ultimate goal of improved interpretation of past biogeochemical conditions and diagenetic processes. PMID:22485113

  14. Mineralogy of iron microbial mats from Loihi Seamount

    Directory of Open Access Journals (Sweden)

    Brandy Marie Toner

    2012-04-01

    Full Text Available Extensive mats of Fe oxyhydroxides and associated Fe-oxidizing microbial organisms form in diverse geochemical settings – freshwater seeps to deep-sea vents – where ever opposing Fe(II-oxygen gradients prevail. The mineralogy, reactivity, and structural transformations of Fe oxyhydroxides precipitated from submarine hydrothermal fluids within microbial mats remains elusive in active and fossil systems. In response, a study of Fe microbial mat formation at the Loihi Seamount was conducted to describe the physical and chemical characteristics of Fe-phases using extended X-ray absorption fine structure spectroscopy, powder X-ray diffraction, synchrotron radiation X-ray total scattering, low-temperature magnetic measurements, and Mössbauer spectroscopy. Particle sizes of 3.5-4.6 nm were estimated from magnetism data, and coherent scattering domain sizes as small as 1.6 nm are indicated by pair distribution function (PDF analysis. Disorder in the nanostructured Fe-bearing phases results in limited intermediate-range structural order: less than that of standard 2-line ferrihydrite (Fh, except for the Pohaku site. The short-range ordered natural Fh (FhSRO phases were stable at 4 °C in the presence of oxygen for at least 1 year and during 400 oC treatment. The observed stability of the FhSRO is consistent with magnetic observations that point to non-interacting nanoparticles. PDF analyses of total scattering data provide further evidence for FhSRO particles with a poorly ordered silica coating. The presence of coated particles explains the small coherent scattering domain for the mat minerals, as well as the stability of the minerals over time and against heating. The mineral properties observed here provide a starting point from which progressively older and more extensively altered iron deposits may be examined, with the ultimate goal of improved interpretation of past biogeochemical conditions and diagenetic processes.

  15. Drying Spirulina with Foam Mat Drying at Medium Temperature

    OpenAIRE

    Aji Prasetyaningrum; Mohamad Djaeni

    2012-01-01

    Spirulina is a single cell blue green microalgae (Cyanobacteria) containing many Phytonutrients (Beta-carotene, Chlorophyl, Xanthophyl, Phyocianin) using as anti-carcinogen in food. Producing dry spirulina by quick drying process at medium temperature is very important to retain the Phytonutrient quality. Currently, the work is still challenging due to the gel formation that block the water diffusion from inside to the surface.  This research studies the performance of foam-mat drying on prod...

  16. Response of cyanobacterial mats to nutrient and salinity changes

    Czech Academy of Sciences Publication Activity Database

    Rejmánková, E.; Komárková, Jaroslava

    2005-01-01

    Roč. 83, č. 2 (2005), s. 87-107. ISSN 0304-3770. [INTECOL International Wetlands Conference /7./. Utrecht, 25.07.2004-30.7.2004] Grant ostatní: NSF(US) 0089211 Institutional research plan: CEZ:AV0Z60170517 Keywords : cyanobacterial mats * Belize * P-N impact Subject RIV: EH - Ecology, Behaviour Impact factor: 1.344, year: 2005

  17. Simulated Carbon Cycling in a Model Microbial Mat.

    Science.gov (United States)

    Decker, K. L.; Potter, C. S.

    2006-12-01

    We present here the novel addition of detailed organic carbon cycling to our model of a hypersaline microbial mat ecosystem. This ecosystem model, MBGC (Microbial BioGeoChemistry), simulates carbon fixation through oxygenic and anoxygenic photosynthesis, and the release of C and electrons for microbial heterotrophs via cyanobacterial exudates and also via a pool of dead cells. Previously in MBGC, the organic portion of the carbon cycle was simplified into a black-box rate of accumulation of simple and complex organic compounds based on photosynthesis and mortality rates. We will discuss the novel inclusion of fermentation as a source of carbon and electrons for use in methanogenesis and sulfate reduction, and the influence of photorespiration on labile carbon exudation rates in cyanobacteria. We will also discuss the modeling of decomposition of dead cells and the ultimate release of inorganic carbon. The detailed modeling of organic carbon cycling is important to the accurate representation of inorganic carbon flux through the mat, as well as to accurate representation of growth models of the heterotrophs under different environmental conditions. Because the model ecosystem is an analog of ancient microbial mats that had huge impacts on the atmosphere of early earth, this MBGC can be useful as a biological component to either early earth models or models of other planets that potentially harbor life.

  18. Hydroponic root mats for wastewater treatment-a review.

    Science.gov (United States)

    Chen, Zhongbing; Cuervo, Diego Paredes; Müller, Jochen A; Wiessner, Arndt; Köser, Heinz; Vymazal, Jan; Kästner, Matthias; Kuschk, Peter

    2016-08-01

    Hydroponic root mats (HRMs) are ecotechnological wastewater treatment systems where aquatic vegetation forms buoyant filters by their dense interwoven roots and rhizomes, sometimes supported by rafts or other floating materials. A preferential hydraulic flow is created in the water zone between the plant root mat and the bottom of the treatment system. When the mat touches the bottom of the water body, such systems can also function as HRM filter; i.e. the hydraulic flow passes directly through the root zone. HRMs have been used for the treatment of various types of polluted water, including domestic wastewater; agricultural effluents; and polluted river, lake, stormwater and groundwater and even acid mine drainage. This article provides an overview on the concept of applying floating HRM and non-floating HRM filters for wastewater treatment. Exemplary performance data are presented, and the advantages and disadvantages of this technology are discussed in comparison to those of ponds, free-floating plant and soil-based constructed wetlands. Finally, suggestions are provided on the preferred scope of application of HRMs. PMID:27164889

  19. Studying Microbial Mat Functioning Amidst "Unexpected Diversity": Methodological Approaches and Initial Results from Metatranscriptomes of Mats Over Diel cycles, iTags from Long Term Manipulations, and Biogeochemical Cycling in Simplified Microbial Mats Constructed from Cultures

    Science.gov (United States)

    Bebout, B.; Bebout, L. E.; Detweiler, A. M.; Everroad, R. C.; Lee, J.; Pett-Ridge, J.; Weber, P. K.

    2014-12-01

    Microbial mats are famously amongst the most diverse microbial ecosystems on Earth, inhabiting some of the most inclement environments known, including hypersaline, dry, hot, cold, nutrient poor, and high UV environments. The high microbial diversity of microbial mats makes studies of microbial ecology notably difficult. To address this challenge, we have been using a combination of metagenomics, metatranscriptomics, iTags and culture-based simplified microbial mats to study biogeochemical cycling (H2 production, N2 fixation, and fermentation) in microbial mats collected from Elkhorn Slough, Monterey Bay, California. Metatranscriptomes of microbial mats incubated over a diel cycle have revealed that a number of gene systems activate only during the day in Cyanobacteria, while the remaining appear to be constitutive. The dominant cyanobacterium in the mat (Microcoleus chthonoplastes) expresses several pathways for nitrogen scavenging undocumented in cultured strains, as well as the expression of two starch storage and utilization cycles. Community composition shifts in response to long term manipulations of mats were assessed using iTags. Changes in community diversity were observed as hydrogen fluxes increased in response to a lowering of sulfate concentrations. To produce simplified microbial mats, we have isolated members of 13 of the 15 top taxa from our iTag libraries into culture. Simplified microbial mats and simple co-cultures and consortia constructed from these isolates reproduce many of the natural patterns of biogeochemical cycling in the parent natural microbial mats, but against a background of far lower overall diversity, simplifying studies of changes in gene expression (over the short term), interactions between community members, and community composition changes (over the longer term), in response to environmental forcing.

  20. Radioresistance studies in Methylobacterium spp

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Fatima; Botelho, M. Luisa; Tenreiro, Rogerio

    1998-06-01

    Methylobacterium extorquens was isolated and was found as one of the most resistant microorganisms in the original bioburden of ophthalmic cotton dressings to be submitted to {gamma} radiation sterilization. Radiation survival curves were simultaneously performed in phosphate buffer and in test-pieces on two isolates, one obtained before irradiation (wild strain) and the other after irradiation at 20 kGy (rad strain), as well as on three type strains of Methylobacterium spp. (M. extorquens{sup T}, M. radiotolerans{sup T} and M. fujisawaense{sup T}). The radiation resistance was compared using D{sub values}. To analyze the effect of non linearity on radioresistance other measures were applied, such as intercept point, fraction of surviving cells at a selected dose and area. The ranking of strains with these approaches showed to be different, pointing out the need of an integrated measure of radioresistance. Therefore, an index of relative survival (IRS) is proposed.

  1. Leptospira spp. antibodies in captive coatis (Nasua nasua Storr, 1780 (Carnivora: Procyonidae

    Directory of Open Access Journals (Sweden)

    H Langoni

    2009-01-01

    Full Text Available Leptospirosis is a worldwide infection that affects many species, including wild animals. The present study aimed to detect Leptospira spp. antibodies in 17 captive coatis (Nasua nasua by the microscopic agglutination test (MAT. Nine (52.94% animals tested positive and the following serovars were identified: Copenhageni (22.22%, Shermani (22.22%, Andamana (11.11%, Wolfii (11.11% and Pyrogenes (11.11%. Two samples presented coagglutination, one (11.11% for Hebdomadis and Wolfii, and another (11.11% for Hebdomadis, Hardjo and Wolfii. The current study revealed the presence of the infection even in animals without any clinical signs, reinforcing the possibility that wild animals in captivity may be infected by leptospire serovars, thus enabling reservoirs.

  2. Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

    Directory of Open Access Journals (Sweden)

    Kirpluks Mikelis

    2014-12-01

    Full Text Available One of the biggest disadvantages of rigid polyurethane (PU foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ, which at 18-28 mW/(m•K is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K. This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.

  3. Diel Metagenomics and Metatranscriptomics of Elkhorn Slough Hypersaline Microbial Mat

    Science.gov (United States)

    Lee, J.; Detweiler, A. M.; Everroad, R. C.; Bebout, L. E.; Weber, P. K.; Pett-Ridge, J.; Bebout, B.

    2014-12-01

    To understand the variation in gene expression associated with the daytime oxygenic phototrophic and nighttime fermentation regimes seen in hypersaline microbial mats, a contiguous mat piece was subjected to sampling at regular intervals over a 24-hour diel period. Additionally, to understand the impact of sulfate reduction on biohydrogen consumption, molybdate was added to a parallel experiment in the same run. 4 metagenome and 12 metatranscriptome Illumina HiSeq lanes were completed over day / night, and control / molybdate experiments. Preliminary comparative examination of noon and midnight metatranscriptomic samples mapped using bowtie2 to reference genomes has revealed several notable results about the dominant mat-building cyanobacterium Microcoleus chthonoplastes PCC 7420. Dominant cyanobacterium M. chthonoplastes PCC 7420 shows expression in several pathways for nitrogen scavenging, including nitrogen fixation. Reads mapped to M. chthonoplastes PCC 7420 shows expression of two starch storage and utilization pathways, one as a starch-trehalose-maltose-glucose pathway, another through UDP-glucose-cellulose-β-1,4 glucan-glucose pathway. The overall trend of gene expression was primarily light driven up-regulation followed by down-regulation in dark, while much of the remaining expression profile appears to be constitutive. Co-assembly of quality-controlled reads from 4 metagenomes was performed using Ray Meta with progressively smaller K-mer sizes, with bins identified and filtered using principal component analysis of coverages from all libraries and a %GC filter, followed by reassembly of the remaining co-assembly reads and binned reads. Despite having relatively similar abundance profiles in each metagenome, this binning approach was able to distinctly resolve bins from dominant taxa, but also sulfate reducing bacteria that are desired for understanding molybdate inhibition. Bins generated from this iterative assembly process will be used for downstream

  4. Electrospun magnetic nanofibre mats – A new bondable biomaterial using remotely activated magnetic heating

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yi [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai (China); Leung, Victor; Yuqin Wan, Lynn [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Dutz, Silvio [Institut für Biomedizinische Technik und Informatik, Technische Universität Ilmenau (Germany); Department of Nano Biophotonics, Leibniz Institute of Photonic Technology, Jena (Germany); Ko, Frank K., E-mail: frank.ko@ubc.ca [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Häfeli, Urs O., E-mail: urs.hafeli@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Canada)

    2015-04-15

    A solvothermal process was adopted to produce hydrophilic magnetite (Fe{sub 3}O{sub 4}) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy.

  5. Electrospun magnetic nanofibre mats - A new bondable biomaterial using remotely activated magnetic heating

    Science.gov (United States)

    Zhong, Yi; Leung, Victor; Yuqin Wan, Lynn; Dutz, Silvio; Ko, Frank K.; Häfeli, Urs O.

    2015-04-01

    A solvothermal process was adopted to produce hydrophilic magnetite (Fe3O4) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy.

  6. Electrospun magnetic nanofibre mats – A new bondable biomaterial using remotely activated magnetic heating

    International Nuclear Information System (INIS)

    A solvothermal process was adopted to produce hydrophilic magnetite (Fe3O4) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy

  7. Solution-blown nanofiber mats from fish sarcoplasmic protein

    DEFF Research Database (Denmark)

    Sett, S.; Boutrup Stephansen, Karen; Yarin, A.L.

    2016-01-01

    In the present work, solution-blowing was adopted to form nanofibers from fish sarcoplasmic proteins (FSPs). Nanofiber mats containing different weight ratios (up to 90/10) of FSP in the FSP/nylon 6 blended nanofibers were formed from formic acid solutions, and compared to electrospun fibers made...... production rate of solution-blowing was increased 30-fold in relation to electrospinning. Overall, this study reveals FSP as an interesting biopolymeric alternative to synthetic polymers, and the introduction of FSP to nylon 6 provides a composite with controlled properties....

  8. Out-of-plane auxeticity in sintered fibre network mats

    International Nuclear Information System (INIS)

    Fibre network mats composed of stainless steel exhibit an unusually large out-of-plane auxeticity (i.e. high negative Poisson’s ratio ν) when subjected to in-plane tensile loading. In situ observations in a scanning electron microscope suggest that this is attributable to fibre segment straightening. An investigation was carried out on the effects of fibre volume fraction and network thickness on the auxetic response. Weak inter-layer bonding, high fibre content and low network thickness were found to amplify the auxetic effect

  9. Superhydrophobic silicone fiber mats fabricated by electrospinning from solution

    Science.gov (United States)

    Ludwig, Bonnie; Clark, Aneta; Snow, Steven; Hill, Randal; Schmidt, Randall; Fogg, Brad; Lo, Peter

    2007-03-01

    Fine silicone fibers of 1 -- 20 μm diameter were fabricated from solution via electrospinning. These are the first examples of fine fibers prepared from silicone homopolymers. Fiber morphology (beaded, ribbon-like, smooth) and diameter were controlled. The nanoscale surface roughness of nonwoven fiber mats created with silicone fibers produced a superhydrophobic surface that had a water contact angle of ˜160^o. The superhydrophobic surface was made reversibly hydrophilic with exposure to oxygen plasma. The combination of high surface area and superhydrophobicity suggests potential applications in the areas of water-repellent textiles, filtration, adsorption and chemical separations, wound dressings, and fuel cells.

  10. An in vitro growth inhibition test for measuring the potency of Leptospira spp. Sejroe group vaccine in buffaloes.

    Science.gov (United States)

    de Nardi, Geraldo; Genovez, Margareth Elide; Ribeiro, Marcio Garcia; Castro, Vanessa; Jorge, André Mendes

    2010-07-01

    Leptospira spp. serovars Hardjo and Wollfi from Sejroe serogroup have been detected in livestock in Brazil, where the main control procedures rely on vaccination. The potency of two commercial vaccines available in this country was monitored by microagglutination test-MAT and in vitro growth inhibition test-GIT in serum samples from 33 female buffaloes divided into: G1-unvaccinated control; G2-vaccinated with Leptobac-6 containing serovars Hardjo and Wolffi and G3-vaccinated with Triangle-9 containing serovar Hardjo. G2 and G3 animals were vaccinated on day zero, and received a booster and two revaccinations on days 30, 210 and 390 and G1 animals received phosphate buffered saline. Serum samples were collected at 15-day intervals between days 0 and 60; and at 30-day intervals between days 60 and 540 and were tested by MAT and GIT with serovars Hardjo and Wolffi. G1 remained negative throughout the experiment. Both vaccines were able to induce agglutinating and growth inhibition antibodies. Six months after the last revaccination, all animals tested negative by MAT, but still were positive by GIT until the end of experimental period. GIT could be a good tool to evaluate the potency and to monitor antibodies responses of vaccines of Sejroe group serovars. PMID:20332068

  11. Niche differentiation of bacterial communities at a millimeter scale in Shark Bay microbial mats

    OpenAIRE

    Hon Lun Wong; Daniela-Lee Smith; Pieter T. Visscher; Burns, Brendan P.

    2015-01-01

    Modern microbial mats can provide key insights into early Earth ecosystems, and Shark Bay, Australia, holds one of the best examples of these systems. Identifying the spatial distribution of microorganisms with mat depth facilitates a greater understanding of specific niches and potentially novel microbial interactions. High throughput sequencing coupled with elemental analyses and biogeochemical measurements of two distinct mat types (smooth and pustular) at a millimeter scale were undertake...

  12. MILLIMETER-SCALE GENETIC GRADIENTS AND COMMUNITY-LEVEL MOLECULAR CONVERGENCE IN A HYPERSALINE MICROBIAL MAT

    Energy Technology Data Exchange (ETDEWEB)

    Fenner, Marsha W; Kunin, Victor; Raes, Jeroen; Harris, J. Kirk; Spear, John R.; Walker, Jeffrey J.; Ivanova, Natalia; Mering, Christian von; Bebout, Brad M.; Pace, Norman R.; Bork, Peer; Hugenholtz, Philip

    2008-04-30

    To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that are consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino acid usage indicating that hypersalinity enforces an overriding selective pressure on the mat community.

  13. Sulfate-reducing bacteria and their activities in cyanobacterial mats of Solar Lake (Sinai, Egypt)

    DEFF Research Database (Denmark)

    Teske, A.; Ramsing, NB; Habicht, K.;

    1998-01-01

    aggregate formation were the most conspicuous adaptations of Solar Lake sulfate-reducing bacteria to the mat matrix and to diurnal oxygen stress. A comparison of sulfate reduction rates within the mat and previously published photosynthesis rates showed that CO2 from sulfate reduction in the upper 5 mm...... accounted for 7 to 8% of the total photosynthetic CO2 demand of the mat.......The sulfate-reducing bacteria within the surface layer of the hypersaline cyanobacterial mat of Solar Lake (Sinai, Egypt) were investigated with combined microbiological, molecular, and biogeochemical approaches. The diurnally oxic surface layer contained between 10(6) and 10(7) cultivable sulfate...

  14. Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

    OpenAIRE

    Min Sup Kim; Sang Jun Park; Bon Kang Gu; Chun-Ho Kim

    2012-01-01

    We describe here the preparation of poly(caprolactone) (PCL)-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of 340.5±2.6 nm, compared with a diameter of 524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angle...

  15. Aligned Electrospun Polyvinyl Pyrrolidone/Poly ɛ-Caprolactone Blend Nanofiber Mats for Tissue Engineering

    Science.gov (United States)

    Charernsriwilaiwat, Natthan; Rojanarata, Theerasak; Ngawhirunpat, Tanasait; Opanasopit, Praneet

    2016-02-01

    Electrospun nanofibrous materials are widely used in medical applications such as tissue engineering scaffolds, wound dressing material and drug delivery carriers. For tissue engineering scaffolds, the structure of the nanofiber is similar to extracellular matrix (ECM) which promotes the cell growth and proliferation. In the present study, the aligned nanofiber mats of polyvinyl pyrrolidone (PVP) blended poly ɛ-caprolactone (PCL) was successfully generated using electrospinning technique. The morphology of PVP/PCL nanofiber mats were characterized by scanning electron microspore (SEM). The chemical and crystalline structure of PVP/PCL nanofiber mats were analyzed using Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffactometer (PXRD). The water contact angle of mats was investigated. Cell culture studies using normal human fibroblasts (NHF) were performed to assess cell morphology, cell alignment and cell proliferation. The results indicated that the fiber were in nanometer range. The PVP/PCL was well dispersed in nanofiber mats and was in amorphous form. The water contact angle of PVP/PCL nanofiber mats was lower than PCL nanofiber mats. The PVP/PCL nanofiber mats exhibited good biocompatibility with NHF cells. In summary, the PVP/PCL nanofiber mats had potential to be used in tissue engineering and regenerative medicine.

  16. The contribution of microbial mats to the arsenic geochemistry of an ancient gold mine

    International Nuclear Information System (INIS)

    The ancient Zloty Stok (SW Poland) gold mine is such an environment, where different microbial communities, able to utilize inorganic arsenic species As(III) and As(V), are found. The purpose of the present study was to (i) estimate prokaryotic diversity in the microbial mats in bottom sediments of this gold mine, (ii) identify microorganisms that can metabolize arsenic, and (iii) estimate their potential role in the arsenic geochemistry of the mine and in the environment. The oxidation/reduction experiments showed that the microbial mat community may significantly contribute to arsenic contamination in groundwater. The presence of both arsenite oxidizing and dissimilatory arsenate reducing bacteria in the mat was confirmed by the detection of arsenite oxidase and dissimilatory arsenate reductase genes, respectively. This work also demonstrated that microorganisms utilizing other compounds that naturally co-occur with arsenic are present within the microbial mat community and may contribute to the arsenic geochemistry in the environment. - Highlights: ► The microbial mats from this ancient gold mine are highly diverse community. ► As(III) oxidizing and As(V) reducing bacteria are present in the mats. ► As redox transformations are linked to the metabolism of microbial mats bacteria. ► Microbial mats play a crucial role in the As biogeochemical cycle within the mine. - The microbial mats from this ancient gold mine can mediate oxidation/reduction reaction of arsenic and in this way may significantly contribute to arsenic contamination in groundwater.

  17. Regeneration in selected Cucurbita spp. germplasm

    OpenAIRE

    Gisbert Domenech, Maria Carmen; Nuez Viñals, Fernando; Picó Sirvent, María Belén

    2011-01-01

    Gisbert Domenech, MC.; Nuez Viñals, F.; Picó Sirvent, MB. (2011). Regeneration in selected Cucurbita spp. germplasm. Report- Cucurbit Genetics Cooperative. 33-34:53-54. http://hdl.handle.net/10251/62926.

  18. Coastal microbial mat diversity along a natural salinity gradient.

    Directory of Open Access Journals (Sweden)

    Henk Bolhuis

    Full Text Available The North Sea coast of the Dutch barrier island of Schiermonnikoog is covered by microbial mats that initiate a succession of plant communities that eventually results in the development of a densely vegetated salt marsh. The North Sea beach has a natural elevation running from the low water mark to the dunes resulting in gradients of environmental factors perpendicular to the beach. These gradients are due to the input of seawater at the low water mark and of freshwater from upwelling groundwater at the dunes and rainfall. The result is a natural and dynamic salinity gradient depending on the tide, rainfall and wind. We studied the microbial community composition in thirty three samples taken every ten meters along this natural salinity gradient by using denaturing gradient gel electrophoresis (DGGE of rRNA gene fragments. We looked at representatives from each Domain of life (Bacteria, Archaea and Eukarya and with a particular emphasis on Cyanobacteria. Analysis of the DGGE fingerprints together with pigment composition revealed three distinct microbial mat communities, a marine community dominated by diatoms as primary producers, an intermediate brackish community dominated by Cyanobacteria as primary producers and a freshwater community with Cyanobacteria and freshwater green algae.

  19. Aeromonas spp. clinical microbiology and disease.

    Science.gov (United States)

    Parker, Jennifer L; Shaw, Jonathan G

    2011-02-01

    Members of the genus Aeromonas inhabit various aquatic environments and are responsible for, and are implicated in, a number of intestinal and extra-intestinal infections in humans as well as other animals. This review focuses on invasive human infection and disease and summarizes available findings regarding the microbiology and detection of Aeromonas spp., with emphasis on successful identification and diagnosis, and the control of disease in the population. Antimicrobial resistance and therapy of Aeromonas spp. is also discussed. PMID:21163298

  20. Vibrio spp. and Salmonella spp., presence and susceptibility in crabs Ucides cordatus Vibrio spp. e Salmonella spp. em caranguejos, Ucides cordatus

    OpenAIRE

    Regine H.S.F. Vieira; Elenice Araújo de Lima; Dannielle Batista Rolim Sousa; Eliane Falavina dos Reis; Renata Garcia Costa; Dália dos Prazeres Rodrigues

    2004-01-01

    The presence of Vibrio spp. and Salmonella spp. in crabs marketed at the Bezerra de Menezes Ave., Fortaleza, State of Ceará, Brazil, was assessed between February and May, 2003. The number of individuals sampled in each one of the fifteen weekly samplings ranged between four and eight. Seven strains of Salmonella, from four different samplings, were identified, being five of them identified as serotype S. Senftenberg and two as S. Poona. All strains of Salmonella were sensitive to the tested ...

  1. Differentiation of Phytopathogenic Agrobacterium spp.

    Directory of Open Access Journals (Sweden)

    Nemanja Kuzmanović

    2011-01-01

    Full Text Available Due to the difficulties in differentiation of phytopathogenic Agrobacterium spp. and lack of a standardized protocol, we carried out selection and evaluation of suitable methods based on the bacterial physiological, genetic and pathogenic properties. Strains of Agrobacterium tumefaciens, A. rhizogenes and A. vitis were differentiated using standard bacteriological and molecular methods. The biochemical and physiological tests confirmed authenticity of the strains. Two duplex PCR methods were conducted with four different primer pairs. In all strains, presence of plasmid virD2 and virC pathogenicity genes was detected. Chromosomal pehA gene was determined in A. vitis strain. Pathogenicity was confirmed on carrot slices and young plants of tomato and sunflower. Strains of A. tumefaciens and A. vitis were pathogenic on all test plants, while strain of A. rhizogenes induced characteristic symptoms only on carrot slices. The tests used in this study provided reliable discrimination between the three species and confirmed their identity as tumorigenic (TiAgrobacterium tumefaciens and A. vitis, and rhizogenic (Ri A. rhizogenes.

  2. Genetic manipulation of Methanosarcina spp.

    Directory of Open Access Journals (Sweden)

    PetraRegine AdelheidKohler

    2012-07-01

    Full Text Available The discovery of the third domain of life, the Archaea, is one of the most exciting findings of the last century. These remarkable prokaryotes are well known for their adaptations to extreme environments; however, Archaea have also conquered moderate environments. Many of the archaeal biochemical processes, such as methane production, are unique in nature and therefore of great scientific interest. Although formerly restricted to biochemical and physiological studies, sophisticated systems for genetic manipulation have been developed during the last two decades for methanogenic archaea, halophilic archaea and thermophilic, sulfur-metabolizing archaea. The availability of these tools has allowed for more complete studies of archaeal physiology and metabolism and most importantly provides the basis for the investigation of gene expression, regulation and function. In this review we provide an overview of methods for genetic manipulation of Methanosarcina spp., a group of methanogenic archaea that are key players in the global carbon cycle and which can be found in a variety of anaerobic environments.

  3. SEROLOGICAL AND MOLECULAR SURVEY OF Leptospira spp. AMONG CART HORSES FROM AN ENDEMIC AREA OF HUMAN LEPTOSPIROSIS IN CURITIBA, SOUTHERN BRAZIL

    Directory of Open Access Journals (Sweden)

    Mariane Angélica Finger

    2014-12-01

    Full Text Available Introduction: Cart horses are a re-emerging population employed to carry recyclable material in cities. Methods: Sixty-two horses were sampled in an endemic area of human leptospirosis. The microscopic agglutination test (MAT and real-time polymerase chain reaction (qPCR were performed. Results: A seropositivity of 75.8% with serovar Icterohaemorrhagiae in 80.8% of the horses was observed. Blood and urine were qPCR negative. MAT showed positive correlations with rainfall (p = 0.02 and flooding (p = 0.03. Conclusions: Although horses may be constantly exposed to Leptospira spp. in the environment mostly because of rainfall and flooding, no leptospiremia or leptospiruria were observed in this study.

  4. SEROLOGICAL AND MOLECULAR SURVEY OF Leptospira spp. AMONG CART HORSES FROM AN ENDEMIC AREA OF HUMAN LEPTOSPIROSIS IN CURITIBA, SOUTHERN BRAZIL

    Science.gov (United States)

    Finger, Mariane Angélica; de Barros, Ivan Roque; Leutenegger, Christian; Estrada, Marko; Ullmann, Leila Sabrina; Langoni, Hélio; Kikuti, Mariana; Dornbush, Peterson Triches; Deconto, Ivan; Biondo, Alexander Welker

    2014-01-01

    Introduction: Cart horses are a re-emerging population employed to carry recyclable material in cities. Methods: Sixty-two horses were sampled in an endemic area of human leptospirosis. The microscopic agglutination test (MAT) and real-time polymerase chain reaction (qPCR) were performed. Results: A seropositivity of 75.8% with serovar Icterohaemorrhagiae in 80.8% of the horses was observed. Blood and urine were qPCR negative. MAT showed positive correlations with rainfall (p = 0.02) and flooding (p = 0.03). Conclusions: Although horses may be constantly exposed to Leptospira spp. in the environment mostly because of rainfall and flooding, no leptospiremia or leptospiruria were observed in this study. PMID:25351539

  5. Metagenomic and metabolic profiling of nonlithifying and lithifying stromatolitic mats of Highborne Cay, The Bahamas.

    Directory of Open Access Journals (Sweden)

    Christina L M Khodadad

    Full Text Available BACKGROUND: Stromatolites are laminated carbonate build-ups formed by the metabolic activity of microbial mats and represent one of the oldest known ecosystems on Earth. In this study, we examined a living stromatolite located within the Exuma Sound, The Bahamas and profiled the metagenome and metabolic potential underlying these complex microbial communities. METHODOLOGY/PRINCIPAL FINDINGS: The metagenomes of the two dominant stromatolitic mat types, a nonlithifying (Type 1 and lithifying (Type 3 microbial mat, were partially sequenced and compared. This deep-sequencing approach was complemented by profiling the substrate utilization patterns of the mats using metabolic microarrays. Taxonomic assessment of the protein-encoding genes confirmed previous SSU rRNA analyses that bacteria dominate the metagenome of both mat types. Eukaryotes comprised less than 13% of the metagenomes and were rich in sequences associated with nematodes and heterotrophic protists. Comparative genomic analyses of the functional genes revealed extensive similarities in most of the subsystems between the nonlithifying and lithifying mat types. The one exception was an increase in the relative abundance of certain genes associated with carbohydrate metabolism in the lithifying Type 3 mats. Specifically, genes associated with the degradation of carbohydrates commonly found in exopolymeric substances, such as hexoses, deoxy- and acidic sugars were found. The genetic differences in carbohydrate metabolisms between the two mat types were confirmed using metabolic microarrays. Lithifying mats had a significant increase in diversity and utilization of carbon, nitrogen, phosphorus and sulfur substrates. CONCLUSION/SIGNIFICANCE: The two stromatolitic mat types retained similar microbial communities, functional diversity and many genetic components within their metagenomes. However, there were major differences detected in the activity and genetic pathways of organic carbon

  6. Unravelling Colletotrichum species associated with Camellia: employing ApMat and GS loci to resolve species in the C. gloeosporioides complex.

    Science.gov (United States)

    Liu, F; Weir, B S; Damm, U; Crous, P W; Wang, Y; Liu, B; Wang, M; Zhang, M; Cai, L

    2015-12-01

    We investigated the phylogenetic diversity of 144 Colletotrichum isolates associated with symptomatic and asymptomatic tissues of Camellia sinensis and other Camellia spp. from seven provinces in China (Fujian, Guizhou, Henan, Jiangxi, Sichuan, Yunnan, Zhejiang), and seven isolates obtained from other countries, including Indonesia, UK, and the USA. Based on multi-locus (ACT, ApMat, CAL, GAPDH, GS, ITS, TUB2) phylogenetic analyses and phenotypic characters, 11 species were distinguished, including nine well-characterised species (C. alienum, C. boninense, C. camelliae, C. cliviae, C. fioriniae, C. fructicola, C. gloeosporioides, C. karstii, C. sia-mense), and two novel species (C. henanense and C. jiangxiense). Of these, C. camelliae proved to be the most dominant and probably host specific taxon occurring on Camellia. An epitype is also designated for the latter species in this study. Colletotrichum jiangxiense is shown to be phylogenetically closely related to the coffee berry pathogen C. kahawae subsp. kahawae. Pathogenicity tests and the pairwise homoplasy index test suggest that C. jiangxiense and C. kahawae subsp. kahawae are two independent species. This study represents the first report of C. alienum and C. cliviae occurring on Camellia sinensis. In addition, our study demonstrated that the combined use of the loci ApMat and GS in a phylogenetic analysis is able to resolve all currently accepted species in the C. gloeosporioides species complex. PMID:26823629

  7. Metagenomic insights into the dominant Fe(II oxidizing Zetaproteobacteria from an iron mat at Lōi’hi, Hawai’I

    Directory of Open Access Journals (Sweden)

    Esther eSinger

    2013-03-01

    Full Text Available Zetaproteobacteria are among the most prevalent Fe(II oxidizing bacteria at deep-sea hydrothermal vents; however, knowledge about their environmental significance is limited. We provide metagenomic insights into an iron mat at the Lōʻihi Seamount, Hawai’I, revealing novel genomic information of locally dominant Zetaproteobacteria lineages. These lineages were previously estimated to account for ~13% of all local Zetaproteobacteria based on 16S clone library data. Biogeochemically relevant genes include nitrite reductases, which were previously not identified in Zetaproteobacteria, sulfide:quinone oxidases, and ribulose-1,5-bisphosphate carboxylase (RuBisCo. Genes assumed to be involved in Fe(II oxidation correlate in synteny and share 70% AASim with those previously identified in the related Zetaproteobacterium Mariprofundus ferrooxydans PV-1. Overall, Zetaproteobacteria genes appear to originate primarily from within the Proteobacteria and the Fe(II oxidizing Leptospirillum spp. and are predicted to facilitate adaptation to a deep-sea hydrothermal vent environment in addition to microaerophilic Fe(II and H2S oxidation. This dataset represents the first metagenomic study of Fe(II oxidizing bacteria (FeOB from an iron oxide mat at a deep-sea hydrothermal habitat.

  8. Prevalence and risk factors for Leptospira spp. in cattle herds in the south central region of Paraná state

    Directory of Open Access Journals (Sweden)

    Vanessa Y Hashimoto

    2012-02-01

    Full Text Available The aim of this study was to determine the prevalence of anti-Leptospira spp. antibodies and the risk factors for Leptospira spp. infection in breeding cattle herds in the south central region of Paraná state. It was based on the statistic delineation/serological samples and information regarding the selected farms employed in the study of bovine brucellosis for Paraná state in the context of National Program for Control and Eradication of Brucellosis and Tuberculosis. A total of 1.880 females aged >24 months from 274 non vaccinated herds were studied. Serum samples were tested for antibodies against Leptospira spp. using microscopic agglutination test (MAT with 22 Leptospira serovars. The epidemiological questionnaire was applied on all the selected farms and aimed to obtain epidemiological data. Hundred eighty one of 274 herds were positive for Leptospira spp./presenting prevalence of positive herds of 66.06% (IC95%=60.12-71,65%. Presence of >43 cattle (OR=3.120; IC=1.418-6.867/animal purchase (OR=2.010; IC=1.154-3.500/rent of pastures (OR=2.925; IC=1.060-8.068 and presence of maternity paddock (OR=1.981; IC=1,068-3,676 were identified as risk factors for leptospirosis due to any serovar in the multivariate logistic regression. Risk factors for leptospirosis due to serovar Hardjo were presence of >43 cattle (OR=3.622; IC=1.512-8,677/animal purchase (OR=3.143; IC=1.557-6.342/rent of pastures (OR=4.070; IC=1.370-12.087 and presence of horses (OR=2.981; IC=1.321-6.726. These results indicate that Leptospira spp. infection is widespread in the south central region of Paraná state and that factors related to the herd characteristic and management are associated with the infection.

  9. Diagnostic study of Cryptosporidium spp. and Giardia spp. in stray dogs and cats in Mosul city, Iraq

    OpenAIRE

    E.D. Hadi; E. G. Suleiman; Q.T. Al-Obadi; S. H. Arslan

    2014-01-01

    The current study revealed the diagnosis of Cryptosporidium spp. and Giardia spp. in fecal samples which collected from stray dogs and cats in Mosul city. The total percentage of infection with oocysts of Cryptosporidium spp. and cysts of Giardia spp. in dogs were 42%, 26%, while the percentages in cats were 52%, 16% respectively and the single infection with oocysts of Cryptosporidium spp. in cats and dogs formed highest rate was 75%, 50% respectively. The infection rate with Cryptosporidium...

  10. Design of Quadric Surfaces Courseware Based on MatLab-GUIDE%基于MatLab-GUIDE的二次曲面课件设计*

    Institute of Scientific and Technical Information of China (English)

    刘奇; 肖凡; 王翠; 周德强

    2013-01-01

    Makes teaching courseware based on the GUIDE of MatLab. Takes quadric surfaces of analytic geometry as an example, designs a friendly human-computer interaction interface in GUIDE, with the aid of program to attain the visualization of graphical complex in analytic geometry, which facilitates the improvement of students,learning interest as well as accelerates the spread and the use of MatLab at teaching.%基于MatLab-GUIDE进行教学课件制作,以解析几何中的二次曲面为例,在GUIDE中设计出人机交互友好界面,借助编程实现解析几何中复杂图形可视化,有利于提高学生学习兴趣,又有利于促进MatLab 在教学中推广和使用。

  11. Seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in Italian horses.

    Science.gov (United States)

    Ebani, Valentina V; Bertelloni, Fabrizio; Pinzauti, Paolo; Cerri, Domenico

    2012-01-01

    The aim of the study was to determine the seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in healthy horses living in 7 provinces of central Italy. In the period 2007-2009, sera from 386 horses were tested by microagglutination test (MAT) to detect antibodies to Leptospira spp., employing the following serovars as antigens: Bratislava, Ballum, Canicola, Icterohaemorrhagiae, Grippotyphosa, Hardjo, Pomona, Tarassovi. 3 animals were positive for the serovars Icterohaemorrhagiae, 2 to Bratislava, and 1 to Pomona, for a total 1.5% seroprevalence. All sera were examined by immunofluorence antibody test (IFAT) to reveal anti-B. burgdorferi s.l. antibodies. 94 (24.3%) horses were positive with antibody titres ranging from 1:64 to 1:1,024. The seroprevalence was significantly higher in >10 year-old horses compared to younger subjects. No significant differences in the mean seroprevalence were observed in the respective years. The total mean seroprevalence were strictly related to the environmental conditions of the areas in which the horses lived. No cross-reactions between Leptospira and Borrelia were observed. This is the first serological survey on antibodies to B. burgdorferi s.l. in Italian horses. PMID:22742794

  12. Occurrence of Babesia spp., Rickettsia spp. and Bartonella spp. in Ixodes ricinus in Bavarian public parks, Germany

    Directory of Open Access Journals (Sweden)

    Mahling Monia

    2011-07-01

    Full Text Available Abstract Background Only limited information is available about the occurrence of ticks and tick-borne pathogens in public parks, which are areas strongly influenced by human beings. For this reason, Ixodes ricinus were collected in public parks of different Bavarian cities in a 2-year survey (2009 and 2010 and screened for DNA of Babesia spp., Rickettsia spp. and Bartonella spp. by PCR. Species identification was performed by sequence analysis and alignment with existing sequences in GenBank. Additionally, coinfections with Anaplasma phagocytophilum were investigated. Results The following prevalences were detected: Babesia spp.: 0.4% (n = 17, including one pool of two larvae in 2009 and 0.5 to 0.7% (n = 11, including one pool of five larvae in 2010; Rickettsia spp.: 6.4 to 7.7% (n = 285, including 16 pools of 76 larvae in 2009. DNA of Bartonella spp. in I. ricinus in Bavarian public parks could not be identified. Sequence analysis revealed the following species: Babesia sp. EU1 (n = 25, B. divergens (n = 1, B. divergens/capreoli (n = 1, B. gibsoni-like (n = 1, R. helvetica (n = 272, R. monacensis IrR/Munich (n = 12 and unspecified R. monacensis (n = 1. The majority of coinfections were R. helvetica with A. phagocytophilum (n = 27, but coinfections between Babesia spp. and A. phagocytophilum, or Babesia spp. and R. helvetica were also detected. Conclusions I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green

  13. Caractérisation et propriétés des "matériaux culturels"... vers une nouvelle discipline en Science des Matériaux

    OpenAIRE

    Robbiola, Luc

    1999-01-01

    This work mainly aims to introduce a new discipline in materials science: the cultural materials science, which is depicted through the example of the bronze alteration. Methodological aspects as well as presentation of research investigation performed both on ancient and modern copper-tin alloys are summarised. Illustrative examples are given. Ce rapport porte principalement sur la mise en place d'une nouvelle discipline en science des matériaux : la science des matériaux culturels. Celle...

  14. Efeito do nível de caroço de algodão sobre a digestibilidade da fibra dietética do feno de Tifton 85 (Cynodon spp.) em ovinos Effect of level of whole cottonseed on digestibility of dietary fiber in sheep

    OpenAIRE

    M.C.P. Rogério; I. Borges; D.A.B. Teixeira; N.M. Rodriguez; L.C. Gonçalves

    2004-01-01

    Vinte e cinco ovinos machos castrados foram submetidos a um delineamento inteiramente ao acaso para avaliar o efeito do nível de caroço de algodão (Gossypium hirsutum) a uma dieta básica de feno de Tifton 85 (Cynodon spp.). Foram estudados os consumos da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB) e extrato etéreo (EE) por unidade de tamanho metabólico e os coeficientes de digestibilidade da fibra detergente neutro, fibra detergente ácido, hemicelulose e celulose. O experime...

  15. Perfect simulation and moment properties for the Matérn type III process

    DEFF Research Database (Denmark)

    Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.

    2010-01-01

    In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound on the...

  16. Polyelectrolyte-Functionalized Nanofiber Mats Control the Collection and Inactivation of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Katrina A. Rieger

    2016-04-01

    Full Text Available Quantifying the effect that nanofiber mat chemistry and hydrophilicity have on microorganism collection and inactivation is critical in biomedical applications. In this study, the collection and inactivation of Escherichia coli K12 was examined using cellulose nanofiber mats that were surface-functionalized using three polyelectrolytes: poly (acrylic acid (PAA, chitosan (CS, and polydiallyldimethylammonium chloride (pDADMAC. The polyelectrolyte functionalized nanofiber mats retained the cylindrical morphology and average fiber diameter (~0.84 µm of the underlying cellulose nanofibers. X-ray photoelectron spectroscopy (XPS and contact angle measurements confirmed the presence of polycations or polyanions on the surface of the nanofiber mats. Both the control cellulose and pDADMAC-functionalized nanofiber mats exhibited a high collection of E. coli K12, which suggests that mat hydrophilicity may play a larger role than surface charge on cell collection. While the minimum concentration of polycations needed to inhibit E. coli K12 was 800 µg/mL for both CS and pDADMAC, once immobilized, pDADMAC-functionalized nanofiber mats exhibited a higher inactivation of E. coli K12, (~97%. Here, we demonstrate that the collection and inactivation of microorganisms by electrospun cellulose nanofiber mats can be tailored through a facile polyelectrolyte functionalization process.

  17. Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Min Sup Kim

    2012-01-01

    Full Text Available We describe here the preparation of poly(caprolactone (PCL-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of 340.5±2.6 nm, compared with a diameter of 524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angles as the proportion of chitin increased. However, the tensile properties of nanofibrous mats containing 30~50% (wt/wt chitin were enhanced compared with PCL-only mats. In vitro studies showed that the viability of human dermal fibroblasts (HDFs for up to 7 days in culture was higher on composite (OD value: 1.42±0.09 than on PCL-only (0.51±0.14 nanofibrous mats, with viability correlated with chitin concentration. Together, our results suggest that PCL-chitin nanofibrous mats can be used as an implantable substrate to modulate HDF viability in tissue engineering.

  18. Using Talking Mats to Support Communication in Persons with Huntington's Disease

    Science.gov (United States)

    Ferm, Ulrika; Sahlin, Anna; Sundin, Linda; Hartelius, Lena

    2010-01-01

    Background: Many individuals with Huntington's disease experience reduced functioning in cognition, language and communication. Talking Mats is a visually based low technological augmentative communication framework that supports communication in people with different cognitive and communicative disabilities. Aims: To evaluate Talking Mats as a…

  19. Physicochemical evolution and positive selection of the gymnosperm matK proteins

    Indian Academy of Sciences (India)

    Da Cheng Hao; Jun Mu; Shi Lin Chen; Pei Gen Xiao

    2010-04-01

    It is not clear whether matK evolves under Darwinian selection. In this study, the gymnosperm Taxaceae, Cephalotaxaceae and Pinaceae were used to illustrate the physicochemical evolution, molecular adaptation and evolutionary dynamics of gene divergence in matKs. matK sequences were amplified from 27 Taxaceae and 12 Cephalotaxaceae species. matK sequences of 19 Pinaceae species were retrieved from GenBank. The phylogenetic tree was generated using conceptual-translated amino acid sequences. Selective influences were investigated using standard $d_{\\text{N}}/d_{\\text{S}}$ ratio methods and more sensitive techniques investigating the amino acid property changes resulting from nonsynonymous replacements in a phylogenetic context. Analyses revealed the presence of positive selection in matKs (N-terminal region, RT domain and domain X) of Taxaceae and Pinaceae, and found positive destabilizing selection in N-terminal region and RT domain of Cephalotaxaceae matK. Moreover, various amino acid properties were found to be influenced by destabilizing positive selection. Amino acid sites relating to these properties and to different secondary structures were found and have the potential to affect group II intron maturase function. Despite the evolutionary constraint on the rapidly evolving matK, this protein evolves under positive selection in gymnosperm. Several regions of matK have experienced molecular adaptation which fine-tunes maturase performance.

  20. Niche differentiation of bacterial communities at a millimeter scale in Shark Bay microbial mats

    Science.gov (United States)

    Wong, Hon Lun; Smith, Daniela-Lee; Visscher, Pieter T.; Burns, Brendan P.

    2015-10-01

    Modern microbial mats can provide key insights into early Earth ecosystems, and Shark Bay, Australia, holds one of the best examples of these systems. Identifying the spatial distribution of microorganisms with mat depth facilitates a greater understanding of specific niches and potentially novel microbial interactions. High throughput sequencing coupled with elemental analyses and biogeochemical measurements of two distinct mat types (smooth and pustular) at a millimeter scale were undertaken in the present study. A total of 8,263,982 16S rRNA gene sequences were obtained, which were affiliated to 58 bacterial and candidate phyla. The surface of both mats were dominated by Cyanobacteria, accompanied with known or putative members of Alphaproteobacteria and Bacteroidetes. The deeper anoxic layers of smooth mats were dominated by Chloroflexi, while Alphaproteobacteria dominated the lower layers of pustular mats. In situ microelectrode measurements revealed smooth mats have a steeper profile of O2 and H2S concentrations, as well as higher oxygen production, consumption, and sulfate reduction rates. Specific elements (Mo, Mg, Mn, Fe, V, P) could be correlated with specific mat types and putative phylogenetic groups. Models are proposed for these systems suggesting putative surface anoxic niches, differential nitrogen fixing niches, and those coupled with methane metabolism.

  1. The architecture of iron microbial mats reflects the adaptation of chemolithotrophic iron oxidation in freshwater and marine environments

    Directory of Open Access Journals (Sweden)

    Clara S Chan

    2016-06-01

    Full Text Available Microbes form mats with architectures that promote efficient metabolism within a particular physicochemical environment, thus studying mat structure helps us understand ecophysiology. Despite much research on chemolithotrophic Fe-oxidizing bacteria, Fe mat architecture has not been visualized because these delicate structures are easily disrupted. There are striking similarities between the biominerals that comprise freshwater and marine Fe mats, made by Beta- and Zetaproteobacteria, respectively. If these biominerals are assembled into mat structures with similar functional morphology, this would suggest that mat architecture is adapted to serve roles specific to Fe oxidation. To evaluate this, we combined light, confocal, and scanning electron microscopy of intact Fe microbial mats with experiments on sheath formation in culture, in order to understand mat developmental history and subsequently evaluate the connection between Fe oxidation and mat morphology. We sampled a freshwater sheath mat from Maine and marine stalk and sheath mats from Loihi Seamount hydrothermal vents, Hawaii. Mat morphology correlated to niche: stalks formed in steeper O2 gradients while sheaths were associated with low to undetectable O2 gradients. Fe-biomineralized filaments, twisted stalks or hollow sheaths, formed the highly porous framework of each mat. The mat-formers are keystone species, with nascent marine stalk-rich mats comprised of novel and uncommon Zetaproteobacteria. For all mats, filaments were locally highly parallel with similar morphologies, indicating that cells were synchronously tracking a chemical or physical cue. In the freshwater mat, cells inhabited sheath ends at the growing edge of the mat. Correspondingly, time lapse culture imaging showed that sheaths are made like stalks, with cells rapidly leaving behind an Fe oxide filament. The distinctive architecture common to all observed Fe mats appears to serve specific functions related to

  2. The Architecture of Iron Microbial Mats Reflects the Adaptation of Chemolithotrophic Iron Oxidation in Freshwater and Marine Environments

    Science.gov (United States)

    Chan, Clara S.; McAllister, Sean M.; Leavitt, Anna H.; Glazer, Brian T.; Krepski, Sean T.; Emerson, David

    2016-01-01

    Microbes form mats with architectures that promote efficient metabolism within a particular physicochemical environment, thus studying mat structure helps us understand ecophysiology. Despite much research on chemolithotrophic Fe-oxidizing bacteria, Fe mat architecture has not been visualized because these delicate structures are easily disrupted. There are striking similarities between the biominerals that comprise freshwater and marine Fe mats, made by Beta- and Zetaproteobacteria, respectively. If these biominerals are assembled into mat structures with similar functional morphology, this would suggest that mat architecture is adapted to serve roles specific to Fe oxidation. To evaluate this, we combined light, confocal, and scanning electron microscopy of intact Fe microbial mats with experiments on sheath formation in culture, in order to understand mat developmental history and subsequently evaluate the connection between Fe oxidation and mat morphology. We sampled a freshwater sheath mat from Maine and marine stalk and sheath mats from Loihi Seamount hydrothermal vents, Hawaii. Mat morphology correlated to niche: stalks formed in steeper O2 gradients while sheaths were associated with low to undetectable O2 gradients. Fe-biomineralized filaments, twisted stalks or hollow sheaths, formed the highly porous framework of each mat. The mat-formers are keystone species, with nascent marine stalk-rich mats comprised of novel and uncommon Zetaproteobacteria. For all mats, filaments were locally highly parallel with similar morphologies, indicating that cells were synchronously tracking a chemical or physical cue. In the freshwater mat, cells inhabited sheath ends at the growing edge of the mat. Correspondingly, time lapse culture imaging showed that sheaths are made like stalks, with cells rapidly leaving behind an Fe oxide filament. The distinctive architecture common to all observed Fe mats appears to serve specific functions related to chemolithotrophic Fe

  3. Relation entre la carie du blé (Tilletia spp.) et son environnement, et propositions de recherches futures pour des agriculteurs en mode de production biologique

    OpenAIRE

    Vidal, Alix

    2012-01-01

    Le rapport se divise en cinq grandes parties : Présentation du contexte de l’étude, recherche bibliographique, matériel et méthodes, résultats et discussion et enfin, les perspectives pour la recherche future. Cette étude comporte deux objectifs principaux. Le premier est de mettre en relation la carie du blé (causée par Tilletia spp.)avec son environnement au sens large. Le second est de proposer des nouveaux angles d’approches pour la recherche future, en accord avec les agriculteurs en mod...

  4. MatLab Programming for Engineers Having No Formal Programming Knowledge

    Science.gov (United States)

    Shaykhian, Linda H.; Shaykhian, Gholam Ali

    2007-01-01

    MatLab is one of the most widely used very high level programming languages for Scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. Also, stated are the current limitations of the MatLab, which possibly can be taken care of by Mathworks Inc. in a future version to make MatLab more versatile.

  5. A Markov Random Field Model-Based Approach to Natural Image Matting

    Institute of Scientific and Technical Information of China (English)

    Sheng-You Lin; Jiao-Ying Shi

    2007-01-01

    This paper proposes a Markov Random Field (MRF) model-based approach to natural image matting with complex scenes.After the trimap for matting is given manually, the unknown region is roughly segmented into several joint sub-regions.In each sub-region, we partition the colors of neighboring background or foreground pixels into several clusters in RGB color space and assign matting label to each unknown pixel.All the labels are modelled as an MRF and the matting problem is then formulated as a maximum a posteriori (MAP) estimation problem.Simulated annealing is used to find the optimal MAP estimation.The better results can be obtained under the same user-interactions when images are complex.Results of natural image matting experiments performed on complex images using this approach are shown and compared in this paper.

  6. Biomedical Applications of Antibacterial Nanofiber Mats Made of Electrospinning with Wire Electrodes

    Directory of Open Access Journals (Sweden)

    Yi-Jun Pan

    2016-02-01

    Full Text Available Twisted stainless steel wires are used as wire electrodes for electrospinning the polyvinyl alcohol (PVA/zinc citrate nanofiber mats. The morphology and diameter of the nanofibers in PVA/zinc citrate nanofiber mats are evaluated. We measured the antibacterial efficacy against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli of the nanofiber mats. We also examined the cell adhesion affinity of mammalian tissue culture cells on these nanofiber mats. Our results indicate that an increase in zinc citrate increases the viscosity and electrical conductivity of PVA solution. In addition, increasing zinc citrate results in a smaller diameter of nanofibers that reaches below 100 nm. According to the antibacterial test results, increasing zinc citrate enlarges the inhibition zone of S. aureus but only has a bacteriostatic effect against E. coli. Finally, cell adhesion test results indicate that all nanofiber mats have satisfactory cell attachment regardless of the content of zinc citrate.

  7. Anti-Leptospira spp. antibodies in cats from the semiarid of the Paraíba State

    Directory of Open Access Journals (Sweden)

    Arthur Willian de Lima Brasil

    2014-12-01

    Full Text Available The aim of this survey was to determine de frequency of anti-Leptospira spp. antibodies and the associated risk factors in stray and domiciled cats in the county of Patos, semiarid region of the Paraíba state. Blood samples from 129 cats (61 domiciled and 68 stray were collected during the period of July to August 2011. For the anti-Leptospira spp. antibody search the microscopic agglutination test (MAT was performed using 24 serovars as antigens. Of the 129 cats examined seven (5.43% were seropositive to serovar Pomona, with titers ranging from 200 to 3,200. Of the stray cats three (4.41% were seropositive, and of the domiciled four (6.56% presented anti-Leptospira spp. serovars. Relating to risk factor analysis the variables and respective categories associated with the higher seropositivity were age/> 48 months (p = 0.001, environment where the animal stays/grass (p = 0.009 and presence of rodents/yes (p = 0.020.

  8. Activation of bovine neutrophils by Brucella spp.

    Science.gov (United States)

    Keleher, Lauren L; Skyberg, Jerod A

    2016-09-01

    Brucellosis is a globally important zoonotic infectious disease caused by gram negative bacteria of the genus Brucella. While many species of Brucella exist, Brucella melitensis, Brucella abortus, and Brucella suis are the most common pathogens of humans and livestock. The virulence of Brucella is largely influenced by its ability to evade host factors, including phagocytic killing mechanisms, which are critical for the host response to infection. The aim of this study was to characterize the bovine neutrophil response to virulent Brucella spp. Here, we found that virulent strains of smooth B. abortus, B. melitensis, B. suis, and virulent, rough, strains of Brucella canis possess similar abilities to resist killing by resting, or IFN-γ-activated, bovine neutrophils. Bovine neutrophils responded to infection with a time-dependent oxidative burst that varied little between Brucella spp. Inhibition of TAK1, or SYK kinase blunted the oxidative burst of neutrophils in response to Brucella infection. Interestingly, Brucella spp. did not induce robust death of bovine neutrophils. These results indicate that bovine neutrophils respond similarly to virulent Brucella spp. In addition, virulent Brucella spp., including naturally rough strains of B. canis, have a conserved ability to resist killing by bovine neutrophils. PMID:27436438

  9. Shareholders settling the dispute inside SPP

    International Nuclear Information System (INIS)

    Legal action against gas distribution company Slovensky plynarensky priemysel (SPP), a.s., Bratislava that was announced by Minister of Economy will not be taken. This suit should have been the climax of a dispute about contracts on consultancy services. According to these contracts the two minority (but managing) shareholders of SPP - Gaz de France and Ruhrgas - would invoice the services of their experts to SPP. These experts advise the SPP in area of restructuring and transformation to a more efficient company. Last week the Minister announced that the ministry reached an agreement with the minority shareholders and that the payments would be suspended with immediate effect. P. Rusko announced that he was expecting to receive a new draft of the contract by February 10. 'The contract will be signed between the shareholders of SPP and it will describe in detail the conditions of services offered,' he said. The new contract will stipulate conditions for any similar contracts to be signed in the future and also the maximum annual value of the contract. Compared to originally agreed amount of 1,2 bn Sk (29,59 mn Eur) payable throughout three years the figures in the new contract will be by several hundreds of thousand crowns lower

  10. Grain trapping by filamentous cyanobacterial and algal mats: implications for stromatolite microfabrics through time.

    Science.gov (United States)

    Frantz, C M; Petryshyn, V A; Corsetti, F A

    2015-09-01

    Archean and Proterozoic stromatolites are sparry or fine-grained and finely laminated; coarse-grained stromatolites, such as many found in modern marine systems, do not appear until quite late in the fossil record. The cause of this textural change and its relevance to understanding the evolutionary history of stromatolites is unclear. Cyanobacteria are typically considered the dominant stromatolite builders through time, but studies demonstrating the trapping and binding abilities of cyanobacterial mats are limited. With this in mind, we conducted experiments to test the grain trapping and binding capabilities of filamentous cyanobacterial mats and trapping in larger filamentous algal mats in order to better understand grain size trends in stromatolites. Mats were cut into squares, inclined in saltwater tanks at angles from 0 to 75° (approximating the angle of lamina in typical stromatolites), and grains of various sizes (fine sand, coarse sand, and fine pebbles) were delivered to their surface. Trapping of grains by the cyanobacterial mats depended strongly on (i) how far filaments protruded from the sediment surface, (ii) grain size, and (iii) the mat's incline angle. The cyanobacterial mats were much more effective at trapping fine grains beyond the abiotic slide angle than larger grains. In addition, the cyanobacterial mats actively bound grains of all sizes over time. In contrast, the much larger algal mats trapped medium and coarse grains at all angles. Our experiments suggest that (i) the presence of detrital grains beyond the abiotic slide angle can be considered a biosignature in ancient stromatolites where biogenicity is in question, and, (ii) where coarse grains are present within stromatolite laminae at angles beyond the abiotic angle of slide (e.g., most modern marine stromatolites), typical cyanobacterial-type mats are probably not solely responsible for the construction, giving insight into the evolution of stromatolite microfabrics through time

  11. Diagnostic study of Cryptosporidium spp. and Giardia spp. in stray dogs and cats in Mosul city, Iraq

    Directory of Open Access Journals (Sweden)

    E.D. Hadi

    2014-06-01

    Full Text Available The current study revealed the diagnosis of Cryptosporidium spp. and Giardia spp. in fecal samples which collected from stray dogs and cats in Mosul city. The total percentage of infection with oocysts of Cryptosporidium spp. and cysts of Giardia spp. in dogs were 42%, 26%, while the percentages in cats were 52%, 16% respectively and the single infection with oocysts of Cryptosporidium spp. in cats and dogs formed highest rate was 75%, 50% respectively. The infection rate with Cryptosporidium spp. and Giardia spp. appeared higher in animals aged less than one year. High percentage of infection with Giardia spp. appeared in the females of cats and dogs were 28.12%, 17.5%, while the high infection rate with oocysts of Cryptosporidium spp. appeared in males of dogs and cats were 50%, 60% respectively

  12. The Architecture of Iron Microbial Mats Reflects the Adaptation of Chemolithotrophic Iron Oxidation in Freshwater and Marine Environments

    OpenAIRE

    Chan, Clara S.; McAllister, Sean M.; Leavitt, Anna H.; Brian T. Glazer; Krepski, Sean T.; Emerson, David

    2016-01-01

    Microbes form mats with architectures that promote efficient metabolism within a particular physicochemical environment, thus studying mat structure helps us understand ecophysiology. Despite much research on chemolithotrophic Fe-oxidizing bacteria, Fe mat architecture has not been visualized because these delicate structures are easily disrupted. There are striking similarities between the biominerals that comprise freshwater and marine Fe mats, made by Beta- and Zetaproteobacteria, respecti...

  13. State carries takes another billions from SPP

    International Nuclear Information System (INIS)

    Financial aspects of activities of the SPP, a.s. are analysed. Economising of SPP of last year means income of 7.8 billions Slovak crowns for exchequer. Besides 3.9 billion of last year's taxes from income the state benefits will be doubled this year. The reason of increase are the dividends which account for 51% share of profit after distinctive deliveries from record clean profit of 8.7 billions Slovak crowns. Dividing of company profit, which doubled in last year to 12.6 billions Slovak crowns was adopted by shareholders in the last week at general assembly of SPP. Gaz de France and Ruhrgas who really began to manage the company in the second half of 2002 will divide remaining 3.7 billions Slovak crowns. (Author)

  14. 75 FR 55360 - In the Matter of Mattingly Testing Services, Inc. Molt, MT; Order Revoking License (Effective...

    Science.gov (United States)

    2010-09-10

    ... be filed in accordance with the NRC E-Filing rule (72 FR 49139, August 28, 2007). The E-Filing... Mattingly Testing Services, Inc. Molt, MT; Order Revoking License (Effective Immediately) I Mattingly... should be revoked. Mattingly's license authorizes possession of radioactive materials that are...

  15. Ulje Fusarium spp. iz sirutke kao supstrata

    OpenAIRE

    Akpinar-Bayizit, Arzu; Tulay OZCAN; Lutfiye YILMAZ-ERSAN; Basoglu, Fikri

    2014-01-01

    Cilj ovog rada bio je istražiti mogućnost sineteze ulja Fusarium spp. koristeći deproteiniziranu sirutku kao izvor ugljika. Ukupni lipidi akumulirani u biomasi gljiva utvrđeni su u rasponu od 0,1467-0,8661 mg lipida po mg biomase. Plinskom kromatografijom utvrđeno je da su glavni sastojci sintetiziranih mikrobnih lipida Fusarium spp: palmitinska kiselina (C16:0), palmitoleinska kiselina (C16:1), stearinska kiselina (C18:0), oleinska kiselina (C18:1) i linolna kiselina (C18:2), te se može zakl...

  16. Spatially-resolved carbon flow through a hypersaline phototrophic microbial mat

    Science.gov (United States)

    Moran, J.; Lindemann, S. R.; Cory, A. B.; Courtney, S.; Cole, J. K.; Fredrickson, J.

    2013-12-01

    Hot Lake is a hypersaline, meromictic lake located in an endorheic basin in north-central Washington. Low annual rainfall and high evaporation rates contribute to the lake's high salinity. The predominant dissolved salt is magnesium sulfate, of which monimolimnion waters may seasonally exceed 2 M concentrations. Induced by its high salinity and meromictic nature, Hot Lake displays an inverse thermal gradient with deep horizons seasonally exceeding 50 °C. Despite extreme conditions, dense benthic microbial mats composed of cyanobacteria, anoxygenic photoheterotrophs, and bacterial heterotroph populations develop in the lake. These mats can exceed 1 cm in thickness and display vertical stratification in color due to bacterial pigmentation. Typical mat stratification includes an orange surface layer underlain by green and purple layers at increasing depth. Carbonates, including aragonite and magnesite, are observed within the mat and their formation is likely induced or influenced by microbial metabolic activities and associated pH excursions. We are exploring the role Hot Lake's microbial mats play in carbon cycling. Cyanobacteria are the dominant CO2-fixing organisms in the mat and we seek to understand the spatial and metabolic controls on how the carbon initially fixed by mat cyanobacteria is transferred to associated heterotrophic populations spread throughout the mat strata. Secondly, we seek to understand the overall net carbon balance of the mat through a growing season. We are using a stable isotope probing approach for assessing carbon uptake and migration through representative mat samples. We performed a series of ex situ incubations of freshly harvested mat samples in lake water amended with 13C-labeled bicarbonate or substrates commonly consumed by heterotrophs (including acetate and glucose) and using multiple stable isotope techniques to track label uptake, residence time, remineralization, and location within the mat. In addition to bulk isotope

  17. Antibacterial electrospun chitosan-polyethylene oxide nanocomposite mats containing ZIF-8 nanoparticles.

    Science.gov (United States)

    Kohsari, Iraj; Shariatinia, Zahra; Pourmortazavi, Seied Mahdi

    2016-10-01

    Antimicrobial chitosan-polyethylene oxide (CS-PEO) nanofiber mats loaded with 3, 5 and 10% (w/w) of zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs, ∼60nm diameter) were developed by electrospinning technique. The CS-PEO-GA-3% ZIF-8 NPs crosslinked with glutaraldehyde (GA) vapor was also prepared. The electrospun mats were characterized by various analysis including FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. The nanofibers had average diameters within the range ∼70-120nm. Antimicrobial activities of the CS-PEO and CS-PEO-3% ZIF-8 mats were evaluated by the viable cell-counting method for determining their effectiveness in reducing or halting the growth of Staphylococcus aureus and Escherichia coli bacteria so that the CS-PEO mat containing 3% ZIF-8 revealed 100% bactericidal activity against both kinds of bacteria. The crosslinked CS-PEO-GA-3% ZIF-8 NPs sample was less thermally stable but more hydrophilic than its related non-crosslinked mat reflecting there was no need to crosslink the fibers using a chemical crosslinker having adverse effects. The highest hydrophobicity and appropriate thermal and tensile properties of CS-PEO-3% ZIF-8 NPs among those of the mats including 5 and 10% ZIF-8 NPs suggested that the mentioned mat is the most suitable sample for food coating applications. PMID:27311504

  18. Modification of PLGA Nanofibrous Mats by Electron Beam Irradiation for Soft Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Jae Baek Lee

    2015-01-01

    Full Text Available Biodegradable poly(lactide-co-glycolide (PLGA has found widespread use in modern medical practice. However, the degradation rate of PLGA should be adjusted for specific biomedical applications such as tissue engineering, drug delivery, and surgical implantation. This study focused on the effect of electron beam radiation on nanofibrous PLGA mats in terms of physical properties and degradation behavior with cell proliferation. PLGA nanofiber mats were prepared by electrospinning, and electron beam was irradiated at doses of 50, 100, 150, 200, 250, and 300 kGy. PLGA mats showed dimensional integrity after electron beam irradiation without change of fiber diameter. The degradation behavior of a control PLGA nanofiber (0 kGy and electron beam-irradiated PLGA nanofibers was analyzed by measuring the molecular weight, weight loss, change of chemical structure, and fibrous morphology. The molecular weight of the PLGA nanofibers decreased with increasing electron beam radiation dose. The mechanical properties of the PLGA nanofibrous mats were decreased with increasing electron beam irradiation dose. Cell proliferation behavior on all electron beam irradiated PLGA mats was similar to the control PLGA mats. Electron beam irradiation of PLGA nanofibrous mats is a potentially useful approach for modulating the biodegradation rate of tissue-specific nonwoven nanofibrous scaffolds, specifically for soft tissue engineering applications.

  19. Cantera Integration with the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

    Science.gov (United States)

    Lavelle, Thomas M.; Chapman, Jeffryes W.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

    2014-01-01

    NASA Glenn Research Center (GRC) has recently developed a software package for modeling generic thermodynamic systems called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS). T-MATS is a library of building blocks that can be assembled to represent any thermodynamic system in the Simulink (The MathWorks, Inc.) environment. These elements, along with a Newton Raphson solver (also provided as part of the T-MATS package), enable users to create models of a wide variety of systems. The current version of T-MATS (v1.0.1) uses tabular data for providing information about a specific mixture of air, water (humidity), and hydrocarbon fuel in calculations of thermodynamic properties. The capabilities of T-MATS can be expanded by integrating it with the Cantera thermodynamic package. Cantera is an object-oriented analysis package that calculates thermodynamic solutions for any mixture defined by the user. Integration of Cantera with T-MATS extends the range of systems that may be modeled using the toolbox. In addition, the library of elements released with Cantera were developed using MATLAB native M-files, allowing for quicker prototyping of elements. This paper discusses how the new Cantera-based elements are created and provides examples for using T-MATS integrated with Cantera.

  20. Fabrication of robust Antheraea assama fibroin nanofibrous mat using ionic liquid for skin tissue engineering.

    Science.gov (United States)

    Srivastava, Chandra Mohan; Purwar, Roli

    2016-11-01

    Electrospinning is an emerging technique used for fabrication of nanofibrous mats for skin tissue engineering applications. The aim of this study centered on fabrication of muga fibroin electrospun mats by using ionic liquid and its characterizations. The muga fibroin extracted from cocoon of Antheraea assama is dissolved in 1-butyl, 3-methyl imidazolium acetate (BMIMAc), a green solvent, to prepare a dope solution for electrospinning. The molecular weight, rheology and structural properties of dope solution are characterized. The process parameters of electrospinning machine such as voltage and concentration of dope solution are varied to obtain nanofibrous mats. The nanofibrous mat having average fiber diameter of 160nm are obtained from 10% w/v concentration of muga fibroin in BMIMAc with an applied voltage of 20KV. The mechanical, structural, physical and thermal properties of muga nanofibrous mat (MNF) are analyzed and compare with muga cast film. The cytocompatibility test is performed using L929 fibroblast cells. It is observed that muga nanofibrous mat support higher growth of fibroblast cells (pefficiency of gentamycin sulphate loaded muga nanofibrous mat are found to be significantly higher (pmaterial for skin tissue engineering. PMID:27524022

  1. Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats

    Directory of Open Access Journals (Sweden)

    Chunhui Xiang

    2016-04-01

    Full Text Available Tensile strength, Young’s modulus, and toughness of electrospun nylon 6 non-woven fiber mats were improved by increasing individual nanofiber strength and fiber–fiber load sharing. Single-walled carbon nanotubes (CNTs were used as reinforcement to increase the strength of the electrospun nylon 6 nanofibers. Young’s modulus, tensile strength, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % solutions increased 51%, 87%, and 136%, respectively, after incorporating 1 wt % CNTs into the nylon 6 nanofibers. Three methods were investigated to enhance fiber–fiber load sharing: increasing friction between fibers, thermal bonding, and solvent bonding. The addition of beaded nylon 6 nanofibers into the non-woven fiber mats to increase fiber-fiber friction resulted in a statistically significantly increase in Young’s modulus over comparable smooth non-woven fiber mats. After annealing, tensile strength, elongation, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % + 10 wt % solutions increased 26%, 28%, and 68% compared to those from 20 wt % solutions. Solvent bonding with formic acid vapor at room temperature for 30 min caused increases of 56%, 67%, and 39% in the Young’s modulus, tensile strength, and toughness of non-woven fiber mats, respectively. The increases attributed to increased individual nanofiber strength and solvent bonding synergistically resulted in the improvement of Young’s modulus of the electrospun nylon 6 non-woven fiber mats.

  2. Geochemical Characteristics and Origin of Tar Mats from the Yaha Field in Tarim Basin,China

    Institute of Scientific and Technical Information of China (English)

    张敏; 张俊; 等

    1999-01-01

    Tar mats were firstly discovered and determined accurately in terrestrial oil and gas reservoirs associated with Lower Tertiary sandstone reservoirs in the Yaha field of the Tarim Basin,China,by thin-layer chromatography-flame ionization detector(TLC-FID)and Rock-Eval analysis.The relative content of asphaltene in gross composition of tar mat extracts accounts for more than 30%,that in the corresponding oil leg less than 20%.In the geochemical description profile of oil gas reservoirs,drastic changes in asphaltene contents between tar mats and oil legs could be discovered.This in an important marker to determine tar mats.Distribution characteristics of saturated and aromaic hydrocarbons from reservoir core extracts and crude oils in the Yaha oil and gas reservoirs in the Tarim Basin are described systematically in this paper,and the results show there are similarities among n-alkane distribution characteristics,biomarker distribution characteristics and their combined characteristics of saturated hydrocarbons,and the geochemical characteristics of aromatic hydrocarbons for tar mats.oil leg,asphaltic sand and crude oil.These characteristics suggest the hydrocarbons in these samples were originated from the common source rocks.However,the geochemical characteristics of tar mats reveales that the mechanism of formation of tar mats is the precipitation of asphaltene from crude oils in petroleum reservoirs caused by increased dissolved gas in oil legs(gas injection).

  3. The micromorphology of Younger Dryas-aged black mats from Nevada, Arizona, Texas and New Mexico

    Science.gov (United States)

    Harris-Parks, Erin

    2016-01-01

    Black mats are organic-rich sediments and soils that form in wet environments associated with spring discharge. Micromorphological and geochemical analyses of 25 black mats dating to the Younger Dryas Chronozone (12.9-11.7 ka) and early Holocene were conducted to determine their composition and depositional environment. Samples were collected from Arizona, New Mexico, Texas and Nevada. Micromorphological analyses were conducted on thin sections using polarized and blue fluorescent light. These analyses determined that black mats contain humic acids, fine (5-20 μm) plant fragments, diatoms, phytoliths, and gastropods. The dominant type of organic matter in black mats is derived from herbaceous plants, contradicting previous studies that supported algal or charcoal sources. Differences in the micromorphological characteristics of the samples revealed that black mats formed as three different types, organic horizons, moist soils and, ponded sediments, depending on their topographic position in relation to the water table. The microscopic evidence found in black mats supports the presence of widespread wet environments in Nevada and Arizona during the Younger Dryas Chronozone, clearly indicating a sustained period of greater effective moisture, optimal for spring discharge and black mat formation.

  4. Symbiotic Relationship of Thiothrix spp. with an Echinoderm†

    Science.gov (United States)

    Brigmon, Robin L.; De Ridder, Chantal

    1998-01-01

    Immunoassay procedures were used to investigate the symbiotic relationship of Thiothrix spp. in the intestinal cecum of the spatangoid species Echinocardium cordatum. Thiothrix spp. were identified in nodule samples from E. cordatum digestive tubes based on microscopic examination, enzyme-linked immunosorbent assay, and indirect immunofluorescence. Thiothrix spp. protein made up as much as 84% of the total protein content of the nodules. This is the first identification of Thiothrix spp. internally symbiotic with marine invertebrates. PMID:9726902

  5. Symbiotic relationship of thiothrix spp. with An echinoderm

    Science.gov (United States)

    Brigmon; De Ridder C

    1998-09-01

    Immunoassay procedures were used to investigate the symbiotic relationship of Thiothrix spp. in the intestinal cecum of the spatangoid species Echinocardium cordatum. Thiothrix spp. were identified in nodule samples from E. cordatum digestive tubes based on microscopic examination, enzyme-linked immunosorbent assay, and indirect immunofluorescence. Thiothrix spp. protein made up as much as 84% of the total protein content of the nodules. This is the first identification of Thiothrix spp. internally symbiotic with marine invertebrates. PMID:9726902

  6. Symbiotic Relationship of Thiothrix spp. with an Echinoderm†

    OpenAIRE

    Brigmon, Robin L.; De Ridder, Chantal

    1998-01-01

    Immunoassay procedures were used to investigate the symbiotic relationship of Thiothrix spp. in the intestinal cecum of the spatangoid species Echinocardium cordatum. Thiothrix spp. were identified in nodule samples from E. cordatum digestive tubes based on microscopic examination, enzyme-linked immunosorbent assay, and indirect immunofluorescence. Thiothrix spp. protein made up as much as 84% of the total protein content of the nodules. This is the first identification of Thiothrix spp. inte...

  7. Structural and functional conservation of fungal MatA and human SRY sex determining proteins

    OpenAIRE

    Czaja, Wioletta; Miller, Karen Y.; Skinner, Michael K.; Bruce L. Miller

    2014-01-01

    Sex determination in animals and fungi is regulated by specific sex determining genes. The Aspergillus nidulans (A.nidulans) mating type gene matA and the human SRY (Sex Determining Region Y) encode proteins containing a single HMG (High Mobility Group) domain. Analysis of the amino acid sequence of MatA and SRY transcription factors revealed significant structural similarity. The human SRY protein is able to functionally replace MatA and drives the sexual cycle in the fungus A. nidulans. Fun...

  8. Occurrence of Cronobacter spp. in retail foods

    Czech Academy of Sciences Publication Activity Database

    Hochel, I.; Růžičková, H.; Krásný, Lukáš; Demnerová, K.

    2012-01-01

    Roč. 112, č. 6 (2012), s. 1257-1265. ISSN 1364-5072 Grant ostatní: GA ČR(CZ) GAP503/10/0664 Institutional research plan: CEZ:AV0Z50200510 Keywords : biotype * antibiotic resistance * Cronobacter spp Subject RIV: CE - Biochemistry Impact factor: 2.196, year: 2012

  9. Variability of Colletotrichum spp in common bean.

    Science.gov (United States)

    Mota, S F; Barcelos, Q L; Dias, M A; Souza, E A

    2016-01-01

    The Colletotrichum genus presents large genetic variability, as demonstrated by the occurrence of several pathogenic races and phenotypic traits. The objective of this study was to characterize 22 strains of C. lindemuthianum and Colletotrichum spp recovered from anthracnose lesions and bean scab, and to verify the relationship between species of the Colletotrichum genus, which inhabit anthracnose and scab lesions. Colony morphology, conidium size, the presence of septa, germination, sporulation, and mycelium growth rates, were analyzed in addition to the presence of mating-type genes, IRAP markers, and pathogenicity. Strains of Colletotrichum spp presented wide variation for all evaluated traits, indicating the presence of different species. Pathogenicity tests verified that the severity of the disease caused by strains of Colletotrichum spp must be evaluated 17 days after inoculation. Molecular analysis showed that only the C. lindemuthianum strains were grouped by the IRAP markers. For the physiological traits, we observed that C. lindemuthianum mycelium growth is slower than that of Colletotrichum spp strains. The information generated in this study confirms variability in the evaluated species of Colletotrichum and may direct future basic and applied studies aiming to control these diseases in common bean. PMID:27173211

  10. UV red fluorescence of Veillonella spp.

    OpenAIRE

    Brazier, J. S.; Riley, T. V.

    1988-01-01

    A total of 34 clinical isolates and 7 type strains of Veillonella spp. were tested for their ability to fluoresce on various culture media. Fluorescence was medium dependent and varied among the species. Scanning absorption spectrophotometry of culture extracts showed that the absorption spectrum of the fluorescent pigment is typical of a metal-free porphyrin.

  11. Biological control of saltcedar (Tamarix spp.) by saltcedar leaf beetles (Diorhabda spp.): effects on small mammals

    Science.gov (United States)

    The spread of introduced saltcedar (Tamarix spp.) throughout many riparian systems across the western United States motivated the introduction of biological control agents that are specific to saltcedar, saltcedar leaf beetles (Diorhabda carinulata, D. elongata; Chrysomelidae). I monitored small mam...

  12. 21 CFR 866.3550 - Salmonella spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Salmonella spp. serological reagents. 866.3550... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella spp. serological reagents. (a) Identification. Salmonella spp. serological reagents are devices...

  13. Detection of Salmonella spp. in oysters by PCR.

    OpenAIRE

    Bej, A K; Mahbubani, M H; Boyce, M. J.; Atlas, R M

    1994-01-01

    PCR DNA amplification of a region of the himA gene of Salmonella typhimurium specifically detected Salmonella spp. In oysters, 1 to 10 cells of Salmonella spp. were rapidly detected by the PCR following a pre-enrichment step to increase sensitivity and to ensure that detection was based on the presence of viable Salmonella spp.

  14. 21 CFR 866.3660 - Shigella spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shigella spp. serological reagents. 866.3660... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3660 Shigella spp. serological reagents. (a) Identification. Shigella spp. serological reagents are devices that consist...

  15. 21 CFR 866.3040 - Aspergillus spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Aspergillus spp. serological reagents. 866.3040... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3040 Aspergillus spp. serological reagents. (a) Identification. Aspergillus spp. serological reagents are devices...

  16. 21 CFR 866.3350 - Leptospira spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Leptospira spp. serological reagents. 866.3350... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3350 Leptospira spp. serological reagents. (a) Identification. Leptospira spp. serological reagents are devices...

  17. 21 CFR 866.3340 - Klebsiella spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Klebsiella spp. serological reagents. 866.3340... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3340 Klebsiella spp. serological reagents. (a) Identification. Klebsiella spp. serological reagents are devices...

  18. 21 CFR 866.3415 - Pseudomonas spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pseudomonas spp. serological reagents. 866.3415... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3415 Pseudomonas spp. serological reagents. (a) Identification. Pseudomonas spp. serological reagents are devices...

  19. 21 CFR 866.3375 - Mycoplasma spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mycoplasma spp. serological reagents. 866.3375... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3375 Mycoplasma spp. serological reagents. (a) Identification. Mycoplasma spp. serological reagents are devices...

  20. 21 CFR 866.3740 - Streptococcus spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Streptococcus spp. serological reagents. 866.3740... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological reagents are...

  1. Improvement of hydrophilic properties of electrospun polyamide-imide fibrous mats by atmospheric-pressure plasma treatment

    Science.gov (United States)

    Park, Soo-Jin; Yop Rhee, Kyong; Jin, Fan-Long

    2015-03-01

    Polyamide-imide (PAI) fibrous mats were fabricated through electrospinning and further treated with atmospheric-pressure plasma. The surface characteristics of the PAI fibrous mats were examined to determine the effect of plasma treatment on the hydrophilic properties. FT-IR, X-ray photoelectron spectroscopy, and contact-angle analysis indicated that the hydrophilicity of the PAI fibrous mats increased upon the introduction of hydrophilic groups by plasma treatment. The concentration of functional groups, including oxygen, and the surface roughness of the PAI fibrous mats increased with increasing treatment time. The optimum plasma treatment time for surface modification of the PAI fibrous mats under atmospheric pressure was 120 s.

  2. Vibrio spp. and Salmonella spp., presence and susceptibility in crabs Ucides cordatus Vibrio spp. e Salmonella spp. em caranguejos, Ucides cordatus

    Directory of Open Access Journals (Sweden)

    Regine H.S.F. Vieira

    2004-08-01

    Full Text Available The presence of Vibrio spp. and Salmonella spp. in crabs marketed at the Bezerra de Menezes Ave., Fortaleza, State of Ceará, Brazil, was assessed between February and May, 2003. The number of individuals sampled in each one of the fifteen weekly samplings ranged between four and eight. Seven strains of Salmonella, from four different samplings, were identified, being five of them identified as serotype S. Senftenberg and two as S. Poona. All strains of Salmonella were sensitive to the tested anti-microbial drugs, with the exception of tetracycline and nalidixic acid, for which an intermediary sensibility was found. The MPN's for Vibrio ranged between 110/g and 110,000/g. Of the forty five Vibrio strains isolated from the crab samples, only 10 were identified up to the species level: two V. alginolyticus and eight V. parahaemolyticus. Bacteria belonging to the Enterobacteriaceae and Pseudomonaceae families were also identified, namely Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pantoea agglomerans and Pseudomonas aeruginosa. The proper cooking of the animals is recommended in order to avoid problems for the consumers of this crustacean.Foram pesquisadas a presença de Vibrio spp. e de Salmonella spp. em caranguejos comercializados na Av. Bezerra de Menezes, Fortaleza, Ceará, Brasil, no período entre fevereiro e maio de 2003. O número de indivíduos em cada, das quinze coletas realizadas, semanalmente, variava entre quatro e oito dependendo do tamanho dos animais, totalizando um número de 90 (noventa animais examinados. Foram identificadas sete cepas de Salmonella spp. provenientes de quatro coletas: cinco foram identificadas como sorovar S. Senftenberg e duas como S. Poona. Todas as cepas de Salmonella, isoladas das amostras de caranguejos, apresentaram sensibilidade aos antimicrobianos testados, com exceção de tetraciclina e ácido nalidíxico para os quais elas apresentaram uma sensibilidade intermediária. Os NMPs

  3. [Obtainment of pineapple juice powder by foam-mat drying].

    Science.gov (United States)

    Beristain, C I; Cortés, R; Casillas, M A; Díaz, R

    1991-06-01

    The foam-mat production and stability using pineapple juice concentrate (25, 30 and 40 degrees Brix), adding a surfactants mixture and maltodextrin (DE 10) as co-adjuvant, stirred in a commercial mixer, was studied. Adequate foam formation conditions were as follows: concentrate of 25 degrees Brix using surface active agents (Sorbac 60-Polisorbac 80) 0.285% surface active agent/total solids, HLB = 6, and stirring time, 7 min. The foam was dehydrated in an oven dried with a horizontal air flow circulation set at 60, 70 and 80 degrees C using 3, 5 and 10 mm bed depths. The best conditions were obtained at 60 degrees C and 5 mm bed depth. The product had a particle size of sieve 40-80, and a moisture content of 3%. It was then packaged in multilayer plastic film and stored at environmental conditions. No brown color formation or mold growth was detected during storage. Pineapple juice and a refreshing drink were prepared. The general acceptability in a community indicated that 95% of the population involved accepted the product. PMID:1811453

  4. Hydrogel-Electrospun Fiber Mat Composite Coatings for Neural Prostheses

    Directory of Open Access Journals (Sweden)

    Ning eHan

    2011-03-01

    Full Text Available Achieving stable, long-term performance of implanted neural prosthetic devices has been challenging because of implantation related neuron loss and a foreign body response that results in encapsulating glial scar formation. To improve neuron-prosthesis integration and form chronic, stable interfaces, we investigated the potential of neurotrophin-eluting hydrogel-electrospun fiber mat (EFM composite coatings. In particular, poly(ethylene glycol-poly(ε-caprolactone (PEGPCL hydrogel- poly(ε-caprolactone (PCL EFM composites were applied as coatings for multielectrode arrays (MEAs. Coatings were stable and persisted on electrode surfaces for over 1 month under an agarose gel tissue phantom and over 9 months in a PBS immersion bath. To demonstrate drug release, a neurotrophin, nerve growth factor (NGF, was loaded in the PEGPCL hydrogel layer, and coating cytotoxicity and sustained NGF release were evaluated using a PC12 cell culture model. Quantitative MTT assays showed that these coatings had no significant toxicity toward PC12 cells, and neurite extension at day 7 and 14 confirmed sustained release of NGF at biologically significant concentrations for at least 2 weeks. Our results demonstrate that hydrogel-EFM composite materials can be applied to neural prostheses as a means to improve neuron-electrode proximity and enhance long-term device performance and function.

  5. Drying Spirulina with Foam Mat Drying at Medium Temperature

    Directory of Open Access Journals (Sweden)

    Aji Prasetyaningrum

    2012-10-01

    Full Text Available Spirulina is a single cell blue green microalgae (Cyanobacteria containing many Phytonutrients (Beta-carotene, Chlorophyl, Xanthophyl, Phyocianin using as anti-carcinogen in food. Producing dry spirulina by quick drying process at medium temperature is very important to retain the Phytonutrient quality. Currently, the work is still challenging due to the gel formation that block the water diffusion from inside to the surface.  This research studies the performance of foam-mat drying on production of dry spirulina. In this method the spirulina was mixed with foaming agent (glair/egg albumen, popular as white egg at 2.5% by weight at air velocity 2.2 m/sec. Here, the effect of spirulina thickness and operational temperature on drying time and quality (Beta-carotene and color were observed. The drying time was estimated based on the measurement of water content in spirulina versus time. Result showed that the thicker spirulina, the longer drying time. Conversely, the higher operational temperature, faster drying time. At thickness ranging 1-3 mm and operational temperature below 70oC, the quality of spirulina can fit the market requirement

  6. Contamination of public parks and squares from Guarulhos (São Paulo State, Brazil ) by Toxocara spp. and Ancylostoma spp.

    OpenAIRE

    Jacó Pereira Marques; Catarina de Rezende Guimarães; Ailton Vilas Boas; Paulo Usignolo Carnaúba; Josué de Moraes

    2012-01-01

    The contaminated soil with mammal feces is an important factor of risk to infection with zoonotic diseases. Amongst these zoonoses are visceral larva migrans and cutaneous larva migrans caused by Toxocara spp. and Ancylostoma spp., respectively. The aim of this study was to assess the environmental contamination by Toxocara spp. eggs and hookworms (Ancylostoma spp.) in public parks and squares in the city of Guarulhos, a metropolitan area of São Paulo, São Paulo State, Brazil. Soil samples we...

  7. Presence of Staphylococcus spp. and Candida spp. in the human oral cavity

    Directory of Open Access Journals (Sweden)

    Martins Clélia Aparecida de Paiva

    2002-01-01

    Full Text Available The presence of yeasts and staphylococci in the oral cavity is important because they can act as supplementary microbiota and in certain situations can cause oral or systemic diseases. The aim of this work was to study the prevalence of Candida spp. and Staphylococcus spp. in the human oral cavity. Oral rinses were collected from sixty-eight individuals according to the technique described by Samaranayake and MacFarlane and then cultured on Sabouraud medium supplemented with chloramphenicol and Baird-Parker agar. After the incubation period, the microorganisms were isolated and identified through biochemical tests. The data obtained were statistically analysed by ANOVA. Candida spp. were isolated from 61.76% of the examined individuals and C. albicans was the more frequently isolated specie. Staphylococcus spp. were isolated from 95.60% of the individuals and 41 strains were coagulase negative (63%. Among the coagulase positive strains, nine were S. aureus, 11 S. hyicus and 4 S. schleiferi subspecie coagulans. No correlation was observed between the counts (cfu of the isolated Candida spp. and Staphylococcus spp.

  8. Lipophilic pigments from cyanobacterial (blue-green algal) and diatom mats in Hamelin Pool, Shark Bay, Western Australia

    Science.gov (United States)

    Palmisano, A. C.; Summons, R. E.; Cronin, S. E.; Des Marais, D. J.

    1989-01-01

    Lipophilic pigments were examined in microbial mat communities dominated by cyanobacteria in the intertidal zone and by diatoms in the subtidal and sublittoral zones of Hamelin Pool, Shark Bay, Western Australia. These microbial mats have evolutionary significance because of their similarity to lithfied stromatolites from the Proterozoic and Early Paleozoic eras. Fucoxanthin, diatoxanthin, diadinoxanthin, beta-carotene, and chlorophylls a and c characterized the diatom mats, whereas cyanobacterial mats contained myxoxanthophyll, zeaxanthin, echinenone, beta-carotene, chlorophyll a and, in some cases, sheath pigment. The presence of bacteriochlorophyll a within the mats suggest a close association of photosynthetic bacteria with diatoms and cyanobacteria. The high carotenoids : chlorophyll a ratios (0.84-2.44 wt/wt) in the diatom mats suggest that carotenoids served a photoprotective function in this high light environment. By contrast, cyanobacterial sheath pigment may have largely supplanted the photoprotective role of carotenoids in the intertidal mats.

  9. Natural antioxidant from yerba maté (Ilex paraguariensis St. Hil. prevents hamburger peroxidation

    Directory of Open Access Journals (Sweden)

    Erica Lemos Ferreira

    2011-08-01

    Full Text Available The aim of this study was to evaluate whether yerba maté alcoholic extracts at very low concentrations (0.01 and 0.1%, prevent/retard lipid peroxidation in beef hamburgers without impairing sensory acceptability. For this TBARs and hexanal levels, fatty acid profile and cholesterol oxides were evaluated as oxidation parameters in beef hamburgers during 90 days' storage. The addition of 0.01% yerba maté ethanolic extracts proved inefficient in restraining the lipid peroxidation while the addition of 0.1% resulted in efficient antioxidant activity. Sensory evaluation of hamburger containing 0.1% yerba maté ethanolic extracts showed good acceptability. Yerba maté ethanolic extracts could entirely or partially replace the phenolic synthetic antioxidants in beef hamburgers only when used at above legally allowed concentrations for antioxidant additives (0.01%.

  10. Marine Microbial Mats and the Search for Evidence of Life in Deep Time and Space

    Science.gov (United States)

    Des Marais, David J.

    2011-01-01

    Cyanobacterial mats in extensive seawater evaporation ponds at Guerrero Negro, Baja California, Mexico, have been excellent subjects for microbial ecology research. The studies reviewed here have documented the steep and rapidly changing environmental gradients experienced by mat microorganisms and the very high rates of biogeochemical processes that they maintained. Recent genetic studies have revealed an enormous diversity of bacteria as well as the spatial distribution of Bacteria, Archaea and Eukarya. These findings, together with emerging insights into the intimate interactions between these diverse populations, have contributed substantially to our understanding of the origins, environmental impacts, and biosignatures of photosynthetic microbial mats. The biosignatures (preservable cells, sedimentary fabrics, organic compounds, minerals, stable isotope patterns, etc.) potentially can serve as indicators of past life on early Earth. They also can inform our search for evidence of any life on Mars. Mars exploration has revealed evidence of evaporite deposits and thermal spring deposits; similar deposits on Earth once hosted ancient microbial mat ecosystems.

  11. Manipulative Experimental Approaches to Addressing Geobiological Questions in Microbial Mat and Stromatolite Research

    Science.gov (United States)

    Bebout, I. Lee

    2005-01-01

    We will present a short synopsis of experimental approaches using greenhouse flume systems to address questions of biogeochemical cycling, mineral formation and 3-d structure for Guerrero Negro microbial mats and Highborne Cay Stromatolites.

  12. El telescopi MAGIC aporta llum al coneixement de la matèria fosca

    OpenAIRE

    Doro, Michele

    2011-01-01

    La matèria fosca és el component majoritari de l'Univers: hi ha quatre vegades més matèria fosca que matèria normal. Tot i així, és una gran desconeguda: no emet ni absorbeix la llum directament i només es veu afectada per la força de la gravetat. Ara bé, quan dues partícules de matèria fosca col·lisionen, es poden aniquilar i generar raigs gamma, que són fotons amb milions de vegades més energia que la llum visible, i que poden ser detectats per instruments com el telescopi MAGIC, un experim...

  13. VocMat projekt - uudsed e-õppe võimalused turismiasjalistele / Heli Tooman

    Index Scriptorium Estoniae

    Tooman, Heli, 1949-

    2008-01-01

    Turismivaldkonna spetsialistidele mõeldud koolitusprojektist VocMat (Vocational Management Training for the Tourism Industry). Projekti partneriteks Eestis on Ettevõtluse Arendamise Sihtasutuse Turismiarenduskeskus ja Tartu Ülikooli Pärnu kolledzh. Lisa: Kokkuvõte

  14. Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) User's Guide

    Science.gov (United States)

    Chapman, Jeffryes W.; Lavelle, Thomas M.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

    2014-01-01

    The Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) software package is an open source, MATLABSimulink toolbox (plug in) that can be used by industry professionals and academics for the development of thermodynamic and controls simulations.

  15. Life in Oligotropic Desert Environments: Contrasting Taxonomic and Functional Diversity of Two Microbial Mats with Metagenomics

    Science.gov (United States)

    Bonilla-Rosso, G.; Peimbert, M.; Olmedo, G.; Alcaraz, L. D.; Eguiarte, L. E.; Souza, V.

    2010-04-01

    The metagenomic analysis of two microbial mats from the oligotrophic waters in the Cuatrociéngas basin reveals large differences both at taxonomic and functional level. These are explained in terms of environmental stability and nutrient availability.

  16. Fabrication and characterization of superhydrophobic and superlipophilic silica nanofibers mats with excellent heat resistance

    Directory of Open Access Journals (Sweden)

    Gao S.

    2016-01-01

    Full Text Available A kind of silica nanofibers (SNF mats with superhydrophobicity and superlipophilicity as well as excellent heat resistance, had been prepared by modifying of 1, 1, 1, 3, 3, 3-hexamethyldisilazane on electrospun SNF mats. The effects of heat treatment time on properties of modified SNF mats were investigated by scanning electron microscopy, nitrogen absorption analysis, X-ray photoelectron spectroscopy, and contact angle measurement. With high specific surface area 240.1 m2/g, the optimal modified SNF mat approached water contact angle (WCA 153.2° and fuel contact angle (FCA 0°, furthermore, even after annealing by 450°C in air for 1h , WCA remained at 135.5° and FCA kept at 3.8°, which opened a new way to improve heat resistance of fuel-water filter paper.

  17. ELECTRO-THERMAL EFFECTS AND DEFORMATION RESPONSE OF CARBON FIBER MAT CEMENT BEAMS

    Institute of Scientific and Technical Information of China (English)

    ZhuSirong; LiZhuoqiu; SongXianhui

    2003-01-01

    A carbon fiber mat is a sheet composed of intercrossing short carbon fibers, which has more stable and lower electrical resistivity compared with dispersed short carbon fiber mixed in cement. Thereby carbon fiber mat cement could exhibit obvious electro-thermal effect. When electrified, the temperature of composite structures made up of cement mortar and carbon fiber mat will rise rapidly. If the temperature field is not uniform, temperature difference will cause structures to deform, which can be used to adjust the deformation of structures. The temperature field and deformation response driven by the electro-thermal effects of a type of carbon fiber mat cement beams are studied. Firstly, the temperature and deformation responses are studied using theories of thermal conduction and elasticity. Secondly, experimental results are given to verify the theoretical solution. These two parts lay the foundation for temperature and deformation adjustment.

  18. The contribution of microbial mats to the arsenic geochemistry of an ancient gold mine.

    Science.gov (United States)

    Drewniak, Lukasz; Maryan, Natalia; Lewandowski, Wiktor; Kaczanowski, Szymon; Sklodowska, Aleksandra

    2012-03-01

    The ancient Zloty Stok (SW Poland) gold mine is such an environment, where different microbial communities, able to utilize inorganic arsenic species As(III) and As(V), are found. The purpose of the present study was to (i) estimate prokaryotic diversity in the microbial mats in bottom sediments of this gold mine, (ii) identify microorganisms that can metabolize arsenic, and (iii) estimate their potential role in the arsenic geochemistry of the mine and in the environment. The oxidation/reduction experiments showed that the microbial mat community may significantly contribute to arsenic contamination in groundwater. The presence of both arsenite oxidizing and dissimilatory arsenate reducing bacteria in the mat was confirmed by the detection of arsenite oxidase and dissimilatory arsenate reductase genes, respectively. This work also demonstrated that microorganisms utilizing other compounds that naturally co-occur with arsenic are present within the microbial mat community and may contribute to the arsenic geochemistry in the environment. PMID:22243864

  19. Electrically conductive polyaniline-coated electrospun poly(vinylidene fluoride mats

    Directory of Open Access Journals (Sweden)

    Claudia eMerlini

    2015-02-01

    Full Text Available Electrically conductive polyaniline (PANI-coated electrospun poly(vinylidene fluoride (PVDF mats were fabricated through aniline (ANI oxidative polymerization on electrospun PVDF mats. The effect of polymerization condition on structure and property of PVDF/PANI mats was investigated. The electrical conductivity and PANI content enhanced significantly with increasing ANI concentration due to the formation of a conducting polymer layer that completely coated the PVDF fibers surface. The PANI deposition on the PVDF fibers surface increased the Young Modulus and the elongation at break reduced significantly. Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR revealed that the electrospun PVDF and PVDF/PANI mats display a polymorph crystalline structure, with absorption bands associated to the β, α and γ phases.

  20. Fabrication and In Vitro/In Vivo Performance of Mucoadhesive Electrospun Nanofiber Mats Containing α-Mangostin.

    Science.gov (United States)

    Samprasit, Wipada; Rojanarata, Theerasak; Akkaramongkolporn, Prasert; Ngawhirunpat, Tanasait; Kaomongkolgit, Ruchadaporn; Opanasopit, Praneet

    2015-10-01

    This study aimed to fabricate mucoadhesive electrospun nanofiber mats containing α-mangostin for the maintenance of oral hygiene and reduction of the bacterial growth that causes dental caries. Synthesized thiolated chitosan (CS-SH) blended with polyvinyl alcohol (PVA) was selected as the mucoadhesive polymer. α-Mangostin was incorporated into the CS-SH/PVA solution and electrospun to obtain nanofiber mats. Scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and tensile strength testing were used to characterize the mats. The swelling degree and mucoadhesion were also determined. The nanofiber mats were further evaluated regarding their α-mangostin content, in vitro α-mangostin release, antibacterial activity, cytotoxicity, in vivo performance, and stability. The results indicated that the mats were in the nanometer range. The α-mangostin was well incorporated into the mats, with an amorphous form. The mats showed suitable tensile strength, swelling, and mucoadhesive properties. The loading capacity increased when the initial amount of α-mangostin was increased. Rapid release of α-mangostin from the mats was achieved. Additionally, a fast bacterial killing rate occurred at the lowest concentration of nanofiber mats when α-mangostin was added to the mats. The mats were less cytotoxic after use for 72 h. Moreover, in vivo testing indicated that the mats could reduce the number of oral bacteria, with a good mouth feel. The mats maintained the amount of α-mangostin for 6 months. The results suggest that α-mangostin-loaded mucoadhesive electrospun nanofiber mats may be a promising material for oral care and the prevention of dental caries. PMID:25716329

  1. Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

    Directory of Open Access Journals (Sweden)

    Jackson Z Lee

    2014-02-01

    Full Text Available Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB. However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico -- permanently submerged Microcoleus microbial mats (GN-S, and intertidal Lyngbya microbial mats (GN-I -- were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl-1,1-dimethylurea (DCMU, molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of dsrA phylotypes were responsible for H2 consumption. Incubation with 13C-acetate and nanoSIMS (secondary ion mass-spectrometry indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi.

  2. Identification of the Mating-Type (MAT) Locus That Controls Sexual Reproduction of Blastomyces dermatitidis

    OpenAIRE

    Li, Wenjun; Sullivan, Thomas D.; Walton, Eric; Averette, Anna Floyd; Sakthikumar, Sharadha; Cuomo, Christina A.; Klein, Bruce S.; Heitman, Joseph

    2013-01-01

    Blastomyces dermatitidis is a dimorphic fungal pathogen that primarily causes blastomycosis in the midwestern and northern United States and Canada. While the genes controlling sexual development have been known for a long time, the genes controlling sexual reproduction of B. dermatitidis (teleomorph, Ajellomyces dermatitidis) are unknown. We identified the mating-type (MAT) locus in the B. dermatitidis genome by comparative genomic approaches. The B. dermatitidis MAT locus resembles those of...

  3. Microfacies analysis of Green River Formation stromatolites and comparison to microbial mat experiments

    Science.gov (United States)

    Miller, S. E.; Bahniuk Rumbelsperger, A. M.; Sauvage, J. F.; Jarrett, A. J.; Petryshyn, V. A.; Corsetti, F. A.; Shapiro, R. S.

    2011-12-01

    Stromatolites were collected from the Laney Member of the Early Eocene Green River Formation near LaClede, Wyoming. LaClede stromatolites are laminated at the micron scale and form domes ~10 cm in diameter. Relatively coarse sediments (>300 μm) fill interdomal depressions, but are rare within fine-grained laminae (a grain size distribution common in Proterozoic stromatolites). On the sides of domes, laminae thin significantly and are nearly vertical. Stromatolite growth and infill sedimentation likely occurred simultaneously, as laminae are draped into interdomal areas and are rarely cut by infill. Grains longer than 200 μm are absent on the steep edges of stromatolite domes, despite the presence of >200 μm grains deposited concomitantly in interdomal depressions. To test whether microbial mats are capable of collecting relatively coarse sediments at steep angles, sedimentation experiments were conducted using cyanobacterial mats collected from Catalina Harbor, Catalina Island, California. Fine (0.125-0.250 mm), medium (0.50-1.0 mm), and coarse (1.0-2.0 mm) sediments were dropped on mats inclined at six angles (15° increments from 0-75°). Coarse grains did not adhere to mats steeper than 45°, and all fine grains were captured by mats at angles less than 45°. All grains that settled on mats were strongly bound after one day of further microbial growth. Although we cannot conclude that fine-grained stromatolites were formed by cyanobacteria, our results suggest that coarse-grained stromatolites (e.g., most modern marine stromatolites) require processes not typically observed in modern cyanobacterial mats (e.g., processes associated with algal eukaryotes, diatoms, and/or copious extracellular polymeric substances, or EPS). Similar sedimentation experiments using other microbial mats, such as those with a thicker coating of EPS or a eukaryotic component, may yield additional information on the origins of coarse- and fine-grained stromatolites. This research was

  4. A strategy for biomimetic hybridization of electrospun fiber mat cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Mavis, Bora, E-mail: bmavis@hacettepe.edu.tr

    2011-10-10

    Concentrated synthetic body fluid (c-SBF) recipes have been used in biomimetic deposition of calcium phosphate (CaP) phases on electrospun polycaprolactone (PCL) fiber mats. However, cross-sections of mats could not be coated entirely when simple soaking methods had been used. In this study, calcium and phosphate sources that are used in typical c-SBF recipes were placed in two compartments which were separated by PCL fiber mats. By varying the concentrations of calcium and phosphate sources in either compartment according to a thermodynamic model, the difference between pH levels of compartments was adjusted. A gradual and homogeneous increase in supersaturation levels was achieved on both sides of the membrane with the onset of diffusion of species through the membrane. The strategy of separation of c-SBF constituents permitted coatings that extended through the cross-section of mats. In addition, types of CaP phases that can be precipitated on opposite sides of the membrane under different conditions were predicted by the same thermodynamic model. It was possible to coat the cross-sections of mats with the targeted phase mixtures by using the developed modeling approach. Highlights: {yields} A strategy for coating cross-sections of electrospun fiber mats is developed. {yields} Constituents of concentrated CPS were separated with mats to be coated. {yields} Both, sides and the cross-sections of fiber mats were coated simultaneously. {yields} Alternative that resulted in a biphasic and a single phase coating on opposite sides was predicted by thermodynamic model used. {yields} Coatings were changed from single phase to biphasic by decreasing the difference in pH values of the compartments.

  5. Sedimentary Parameters Controlling Occurrence and Preservation of Microbial Mats in Siliciclastic Depositional Systems

    Science.gov (United States)

    Noffke, Nora; Knoll, Andrew H.

    2001-01-01

    Shallow-marine, siliciclastic depositional systems are governed by physical sedimentary processes. Mineral precipitation or penecontemporaneous cementation play minor roles. Today, coastal siliciclastic environments may be colonized by a variety of epibenthic, mat-forming cyanobacteria. Studies on microbial mats showed that they are not randomly distributed in modern tidal environments. Distribution and abundancy is mainly function of a particular sedimentary facies. Fine-grained sands composed of "clear" (translucent) quartz particles constitute preferred substrates for cyanobacteria. Mat-builders also favor sites characterized by moderate hydrodynamic flow regimes, which permit biomass enrichment and construction of mat fabrics without lethal burial of mat populations by fine sediments. A comparable facies relationship can be observed in ancient siliciclastic shelf successions from the terminal Neoproterozoic Nama Group, Namibia. Wrinkle structures that record microbial mats are present but sparsely distributed in mid- to inner shelf sandstones of the Nudaus Formation. The sporadic distribution of these structures reflects both the narrow ecological window that governs mat development and the distinctive taphonomic conditions needed to preserve the structures. These observations caution that statements about changing mat abundance across the Proterozoic-Cambrian boundary must be firmly rooted in paleoenvironmental and taphonomic analysis. Understanding the factors that influence the formation and preservation of microbial structures in siliciclastic regimes can facilitate exploration for biological signatures in Earth's oldest rocks. Moreover, insofar as these structures can be preserved on bedding surfaces and are not easily mimicked by physical processes, they constitute a set of biological markers that can be searched for on Mars by remotely controlled rovers.

  6. A strategy for biomimetic hybridization of electrospun fiber mat cross-sections

    International Nuclear Information System (INIS)

    Concentrated synthetic body fluid (c-SBF) recipes have been used in biomimetic deposition of calcium phosphate (CaP) phases on electrospun polycaprolactone (PCL) fiber mats. However, cross-sections of mats could not be coated entirely when simple soaking methods had been used. In this study, calcium and phosphate sources that are used in typical c-SBF recipes were placed in two compartments which were separated by PCL fiber mats. By varying the concentrations of calcium and phosphate sources in either compartment according to a thermodynamic model, the difference between pH levels of compartments was adjusted. A gradual and homogeneous increase in supersaturation levels was achieved on both sides of the membrane with the onset of diffusion of species through the membrane. The strategy of separation of c-SBF constituents permitted coatings that extended through the cross-section of mats. In addition, types of CaP phases that can be precipitated on opposite sides of the membrane under different conditions were predicted by the same thermodynamic model. It was possible to coat the cross-sections of mats with the targeted phase mixtures by using the developed modeling approach. Highlights: → A strategy for coating cross-sections of electrospun fiber mats is developed. → Constituents of concentrated CPS were separated with mats to be coated. → Both, sides and the cross-sections of fiber mats were coated simultaneously. → Alternative that resulted in a biphasic and a single phase coating on opposite sides was predicted by thermodynamic model used. → Coatings were changed from single phase to biphasic by decreasing the difference in pH values of the compartments.

  7. Long‐Range Proton Conduction across Free‐Standing Serum Albumin Mats

    OpenAIRE

    Amdursky, Nadav; Wang, Xuhua; Meredith, Paul; Bradley, Donal D. C.; Stevens, Molly M.

    2016-01-01

    Free‐standing serum‐albumin mats can transport protons over millimetre length‐scales. The results of photoinduced proton transfer and voltage‐driven proton‐conductivity measurements, together with temperature‐dependent and isotope‐effect studies, suggest that oxo‐amino‐acids of the protein serum albumin play a major role in the translocation of protons via an “over‐the‐barrier” hopping mechanism. The use of proton‐conducting protein mats opens new possibilities for bioelectronic interfaces....

  8. Structural, mechanical, and tribological properties of electrospun poly(hexamethylene adipamide) fiber mats

    OpenAIRE

    Mannarino, Matthew M.; Katsumata, Reika; Gregory C. Rutledge

    2013-01-01

    The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility in a large number of applications. In this work, mats of electrospun fibers of poly(hexamethylene adipamide) (PA 6,6) with average fiber diameter of 238±22 nm are characterized for their crystal structure as well as their mechanical and tribological properties. Post-spin thermal annealing was used to modify the fiber morphology and crystallinity within the fibers. Morphological ch...

  9. Loss of matK RNA editing in seed plant chloroplasts

    Directory of Open Access Journals (Sweden)

    Maier Uwe G

    2009-08-01

    Full Text Available Abstract Background RNA editing in chloroplasts of angiosperms proceeds by C-to-U conversions at specific sites. Nuclear-encoded factors are required for the recognition of cis-elements located immediately upstream of editing sites. The ensemble of editing sites in a chloroplast genome differs widely between species, and editing sites are thought to evolve rapidly. However, large-scale analyses of the evolution of individual editing sites have not yet been undertaken. Results Here, we analyzed the evolution of two chloroplast editing sites, matK-2 and matK-3, for which DNA sequences from thousands of angiosperm species are available. Both sites are found in most major taxa, including deep-branching families such as the nymphaeaceae. However, 36 isolated taxa scattered across the entire tree lack a C at one of the two matK editing sites. Tests of several exemplary species from this in silico analysis of matK processing unexpectedly revealed that one of the two sites remain unedited in almost half of all species examined. A comparison of sequences between editors and non-editors showed that specific nucleotides co-evolve with the C at the matK editing sites, suggesting that these nucleotides are critical for editing-site recognition. Conclusion (i Both matK editing sites were present in the common ancestor of all angiosperms and have been independently lost multiple times during angiosperm evolution. (ii The editing activities corresponding to matK-2 and matK-3 are unstable. (iii A small number of third-codon positions in the vicinity of editing sites are selectively constrained independent of the presence of the editing site, most likely because of interacting RNA-binding proteins.

  10. Teaching Finite Element Method of Structural Line Elements Assisted by Open Source FreeMat

    OpenAIRE

    Waluyo Adi Siswanto; Agung Setyo Darmawan

    2012-01-01

    One of the important objectives in teaching finite element method at introductory level is to bring students into the comprehension of finite element procedures. This study presents a strategy of teaching structural line elements involving an open source computer-aided learning tool FreeMat integrated with another open source CALFEM finite element toolbox. FreeMat, which is a programming based learning tool, is used together with other higher level learning tools; Open/Libre Office Spreadshee...

  11. A novel procedure to measure the antioxidant capacity of Yerba maté extracts

    OpenAIRE

    Vanessa Graciela Hartwig; Luis Alberto Brumovsky; Raquel María Fretes; Lucila Sánchez Boado

    2012-01-01

    Yerba maté extracts have in vitro antioxidant capacity attributed to the presence of polyphenolic compounds, mainly chlorogenic acids and dicaffeoylquinic acid derivatives. DPPH is one of the most used assays to measure the antioxidant capacity of pure compounds and plant extracts. It is difficult to compare the results between studies because this assay is applied in too many different conditions by the different research groups. Thus, in order to assess the antioxidant capacity of yerba mat...

  12. Learning Geomicrobiology as a Team Using Microbial Mats, a Multidisciplinary Approach

    OpenAIRE

    Visscher, Pieter T.; Lilliam Casillas-Martinez; Carlos Rios-Velazquez

    2009-01-01

    Microbial mats are one of the best suited laminar organo-sedimentary ecosystems for students from different educational backgrounds to visualize the direct relationship between microbes and minerals. We have used tropical hypersaline microbial mats from Puerto Rico as educational tools to promote active learning of geomicrobiology introductory concepts for undergraduate students organized in multidisciplinary teams with biological and geological backgrounds. Besides field trips and independen...

  13. Bioremediation of Acetochlor in Soil and Water Systems by Cyanobacterial Mat

    OpenAIRE

    Yasser El-Nahhal; Yousef Awad; Jamal Safi

    2013-01-01

    This study investigated the bioremediation of organic pollution in soil and water systems by cyanobacterial mats collected from Wadi Gaza. Acetochlor, a model compound of herbicide, was used as a standard organic pollutant. Various concentrations of acetochlor were injected in soil and water samples pre-treated with cyanobacterial mat for several periods of time. Percentage of growth of wheat as a test plant was taken as indicator of bioremediation of acetochlor. Results showed that acetoc...

  14. Targeting accurate object extraction from an image: a comprehensive study of natural image matting.

    Science.gov (United States)

    Zhu, Qingsong; Shao, Ling; Li, Xuelong; Wang, Lei

    2015-02-01

    With the development of digital multimedia technologies, image matting has gained increasing interests from both academic and industrial communities. The purpose of image matting is to precisely extract the foreground objects with arbitrary shapes from an image or a video frame for further editing. It is generally known that image matting is inherently an ill-posed problem because we need to output three images out of only one input image. In this paper, we provide a comprehensive survey of the existing image matting algorithms and evaluate their performance. In addition to the blue screen matting, we systematically divide all existing natural image matting methods into four categories: 1) color sampling-based; 2) propagation-based; 3) combination of sampling-based and propagation-based; and 4) learning-based approaches. Sampling-based methods assume that the foreground and background colors of an unknown pixel can be explicitly estimated by examining nearby pixels. Propagation-based methods are instead based on the assumption that foreground and background colors are locally smooth. Learning-based methods treat the matting process as a supervised or semisupervised learning problem. Via the learning process, users can construct a linear or nonlinear model between the alpha mattes and the image colors using a training set to estimate the alpha matte of an unknown pixel without any assumption about the characteristics of the testing image. With three benchmark data sets, the various matting algorithms are evaluated and compared using several metrics to demonstrate the strengths and weaknesses of each method both quantitatively and qualitatively. Finally, we conclude this paper by outlining the research trends and suggesting a number of promising directions for future development. PMID:25423658

  15. Community structure and function of high-temperature chlorophototrophic microbial mats inhabiting diverse geothermal environments

    DEFF Research Database (Denmark)

    Klatt, Christian G.; Inskeep, William P.; Herrgard, Markus;

    2013-01-01

    Six phototrophic microbial mat communities from different geothermal springs (YNP) were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across...... the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average 53Mbp/site) were...

  16. Microbial Mats on the Orkney Islands Revisited: Microenvironment and Microbial Community Composition

    DEFF Research Database (Denmark)

    Wieland, A.; Kühl, M.; McGowan, L.;

    2003-01-01

    The microenvironment and community composition of microbial mats developing on beaches in Scapa Flow (Orkney Islands) were investigated. Analysis of characteristic biomarkers (major fatty acids, hydrocarbons, alcohols, and alkenones) revealed the presence of different groups of bacteria and...... from CLSM (confocal laser scanning microscopy) analysis. Spectral scalar irradiance measurements with fiber-optic microprobes indicated a pronounced heterogeneity concerning zonation and density of mainly anoxygenic phototrophs in Swanbister Bay mats. By microsensor and T-RFLP (terminal restriction...

  17. Engineering and Scientific Applications: Using MatLab(Registered Trademark) for Data Processing and Visualization

    Science.gov (United States)

    Sen, Syamal K.; Shaykhian, Gholam Ali

    2011-01-01

    MatLab(TradeMark)(MATrix LABoratory) is a numerical computation and simulation tool that is used by thousands Scientists and Engineers in many countries. MatLab does purely numerical calculations, which can be used as a glorified calculator or interpreter programming language; its real strength is in matrix manipulations. Computer algebra functionalities are achieved within the MatLab environment using "symbolic" toolbox. This feature is similar to computer algebra programs, provided by Maple or Mathematica to calculate with mathematical equations using symbolic operations. MatLab in its interpreter programming language form (command interface) is similar with well known programming languages such as C/C++, support data structures and cell arrays to define classes in object oriented programming. As such, MatLab is equipped with most of the essential constructs of a higher programming language. MatLab is packaged with an editor and debugging functionality useful to perform analysis of large MatLab programs and find errors. We believe there are many ways to approach real-world problems; prescribed methods to ensure foregoing solutions are incorporated in design and analysis of data processing and visualization can benefit engineers and scientist in gaining wider insight in actual implementation of their perspective experiments. This presentation will focus on data processing and visualizations aspects of engineering and scientific applications. Specifically, it will discuss methods and techniques to perform intermediate-level data processing covering engineering and scientific problems. MatLab programming techniques including reading various data files formats to produce customized publication-quality graphics, importing engineering and/or scientific data, organizing data in tabular format, exporting data to be used by other software programs such as Microsoft Excel, data presentation and visualization will be discussed.

  18. Serologic survey for Leptospira spp. in captive neotropical felids in Foz do Iguaçu, Paraná, Brazil.

    Science.gov (United States)

    Ullmann, Leila Sabrina; Hoffmann, Juliano L; de Moraes, Wanderlei; Cubas, Zalmir S; dos Santos, Leonilda Correia; da Silva, Rodrigo Costa; Moreira, Nei; Guimaraes, Ana Marcia Sa; Camossi, Lucilene Granuzzio; Langoni, Helio; Biondo, Alexander W

    2012-06-01

    Leptospirosis is a bacterial zoonosis of worldwide distribution and is endemic in tropical countries, where rodents and other wild mammals are abundant and may act as reservoirs. Leptospirosis has become a concern in captive wild animals, due mostly to their exposure to contaminated urine or environment. Although domestic cats (Felis catus) have been reported refractory to leptospirosis, serology and disease in captive wild felids is still unclear. In this study 57 adult, clinically healthy felids, including 1 Geoffroy's cat (Leopardus geoffroyi), 3 jaguarundis (Puma yagouaroundi), 17 margays (Leopardus wiedii), 22 little spotted cats (Leopardus tigrinus), and 14 ocelots (Leopardus pardalis) kept in captivity at the Sanctuary at the Itaipu Binacional hydroelectric power plant (Bela Vista Biological Sanctuary), Foz do Iguacu City, Paraná State, Brazil, were serologically surveyed for the presence of antibodies against 28 serovars of Leptospira spp. by microagglutination test (MAT). Two animals (3.5%) were seropositive: one male ocelot to the serovar Cynopteri (titer 100) and one female margay to Autumnalis (100) and Butembo (200). The captive-born, 5-yr-old ocelot had been solitary housed in an individual cage. The approximately 21-yr-old wild-caught margay was also kept individually. None of the tested animals showed signs ofleptospirosis. During a study conducted 4 yr previously in the same facility, this particular margay also tested positive for the same two serovars, among others. The present study indicates that the felids tested for Leptospira spp. by MAT were exposed to serovars, but did not demonstrate clinical signs of disease. Comparison with a previous study suggests that serovar titers may vary over time and that leptospirosis dynamics remains unclear in wild felids. PMID:22779223

  19. Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

    Directory of Open Access Journals (Sweden)

    Yongfang Qian

    2014-01-01

    Full Text Available Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θ of 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.

  20. Regulation of mat responses by a differentiation MAPK pathway in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Sheelarani Karunanithi

    Full Text Available Fungal species exhibit diverse behaviors when presented with extracellular challenges. Pathogenic fungi can undergo cell differentiation and biofilm formation in response to fluctuating nutrient levels, and these responses are required for virulence. In the model fungal eukaryote Saccharomyces cerevisiae, nutrient limitation induces filamentous growth and biofilm/mat formation. Both responses require the same signal transduction (MAPK pathway and the same cell adhesion molecule (Flo11 but have been studied under different conditions. We found that filamentous growth and mat formation are aspects of a related response that is regulated by the MAPK pathway. Cells in yeast-form mats differentiated into pseudohyphae in response to nutrient limitation. The MAPK pathway regulated mat expansion (in the plane of the XY-axis and substrate invasion (downward in the plane of the Z-axis, which optimized the mat's response to extracellular nutrient levels. The MAPK pathway also regulated an upward growth pattern (in the plane of the Z-axis in response to nutrient limitation and changes in surface rigidity. Upward growth allowed for another level of mat responsiveness and resembled a type of colonial chemorepulsion. Together our results show that signaling pathways play critical roles in regulating social behaviors in which fungal cells participate. Signaling pathways may regulate similar processes in pathogens, whose highly nuanced responses are required for virulence.

  1. Unraveling the stratification of an iron-oxidizing microbial mat by metatranscriptomics.

    Directory of Open Access Journals (Sweden)

    Achim Quaiser

    Full Text Available A metatranscriptomic approach was used to study community gene expression in a naturally occurring iron-rich microbial mat. Total microbial community RNA was reversely transcribed and sequenced by pyrosequencing. Characterization of expressed gene sequences provided accurate and detailed information of the composition of the transcriptionally active community and revealed phylogenetic and functional stratifications within the mat. Comparison of 16S rRNA reads and delineation of OTUs showed significantly lower values of metatranscriptomic-based richness and diversity in the upper parts of the mat than in the deeper regions. Taxonomic affiliation of rRNA sequences and mRNA genome recruitments indicated that iron-oxidizing bacteria affiliated to the genus Leptothrix, dominated the community in the upper layers of the mat. Surprisingly, type I methanotrophs contributed to the majority of the sequences in the deep layers of the mat. Analysis of mRNA expression patterns showed that genes encoding the three subunits of the particulate methane monooxygenase (pmoCAB were the most highly expressed in our dataset. These results provide strong hints that iron-oxidation and methane-oxidation occur simultaneously in microbial mats and that both groups of microorganisms are major players in the functioning of this ecosystem.

  2. Protein and Bacterial Antifouling Behavior of Melt-Coextruded Nanofiber Mats.

    Science.gov (United States)

    Kim, Si-Eun; Zhang, Cong; Advincula, Abigail A; Baer, Eric; Pokorski, Jonathan K

    2016-04-13

    Antifouling surfaces are important for biomedical devices to prevent secondary infections and mitigate the effects of the foreign body response. Herein, we describe melt-coextruded poly(ε-caprolactone) (PCL) nanofiber mats grafted with antifouling polymers. Nonwoven PCL fiber mats are produced using a multilayered melt coextrusion process followed by high-pressure hydroentanglement to yield porous patches. The resulting fiber mats show submicrometer cross-sectional fiber dimensions and yield pore sizes that were nearly uniform, with a mean pore size of 1.6 ± 0.9 μm. Several antifouling polymers, including hydrophilic, zwitterionic, and amphipathic molecules, are grafted to the surface of the mats using a two-step procedure that includes photochemistry followed by the copper-catalyzed azide-alkyne cycloaddition reaction. Fiber mats are evaluated using separate adsorption tests for serum proteins and E. coli. The results indicate that poly(oligo(ethylene glycol) methyl ether methacrylate)-co-(trifluoroethyl methacrylate) (poly(OEGMEMA-co-TFEMA)) grafted mats exhibit approximately 85% less protein adhesion and 97% less E. coli adsorption when compared to unmodified PCL fibermats. In dynamic antifouling testing, the amphiphilic fluorous polymer surface shows the highest flux and highest rejection value of foulants. The work presented within has implications on the high-throughput production of antifouling microporous patches for medical applications. PMID:27043205

  3. Using MatContM in the study of a nonlinear map in economics

    Science.gov (United States)

    Neirynck, Niels; Al-Hdaibat, Bashir; Govaerts, Willy; Kuznetsov, Yuri A.; Meijer, Hil G. E.

    2016-02-01

    MatContM is a MATLAB interactive toolbox for the numerical study of iterated smooth maps, their Lyapunov exponents, fixed points, and periodic, homoclinic and heteroclinic orbits as well as their stable and unstable invariant manifolds. The bifurcation analysis is based on continuation methods, tracing out solution manifolds of various types of objects while some of the parameters of the map vary. In particular, MatContM computes codimension 1 bifurcation curves of cycles and supports the computation of the normal form coefficients of their codimension two bifurcations, and allows branch switching from codimension 2 points to secondary curves. MatContM builds on an earlier command-line MATLAB package CL MatContM but provides new computational routines and functionalities, as well as a graphical user interface, enabling interactive control of all computations, data handling and archiving. We apply MatContM in our study of the monopoly model of T. Puu with cubic price and quadratic marginal cost functions. Using MatContM, we analyze the fixed points and their stability and we compute branches of solutions of period 5, 10, 13 17. The chaotic and periodic behavior of the monopoly model is further analyzed by computing the largest Lyapunov exponents.

  4. Sequester of metals and mineralization of organic contaminants with microbial mats

    International Nuclear Information System (INIS)

    Several recalcitrant organic contaminants are completely mineralized to simple products by microbial mats. Contaminants include chlordane, PCB, TNT, petroleum distillates, BM compounds and TCE in a mixed contaminant solution containing Zn. Degradation rates are relatively rapid under both dark and light conditions. In addition to complete degradation of organic materials, mats have been used to reduce selenate to elemental selenium, remove Pb, Cd, Cu, Zn, Co, Cr, Fe and Mn from water and sequester uranium (U238) at a rate of 3.19 mg/m2/h. Results of three pilot projects, including field pond treatment of mine drainage and bioreactor treatment of BTEX compounds will be reported. Microbial mats are natural heterotrophic and autotrophic communities dominated by cyanobacteria (blue-green algae). They are self-organized laminated structures annealed fightly together by slimy secretions from various microbial components. The surface slime of the mats effectively immobilizes the ecosystem to a variety of substrates, thereby stabilizing the most efficient internal microbial structure. Cyanobacteria mats are generated for bioremediation applications by enriching a water surface with ensiled grass clippings together with mat inocula developed in the laboratory

  5. MatProps: Material Properties Database and Associated Access Library

    Energy Technology Data Exchange (ETDEWEB)

    Durrenberger, J K; Becker, R C; Goto, D M; Neely, J R; Wallin, B K

    2007-08-13

    Coefficients for analytic constitutive and equation of state models (EOS), which are used by many hydro codes at LLNL, are currently stored in a legacy material database (Steinberg, UCRL-MA-106349). Parameters for numerous materials are available through this database, and include Steinberg-Guinan and Steinberg-Lund constitutive models for metals, JWL equations of state for high explosives, and Mie-Gruniesen equations of state for metals. These constitutive models are used in most of the simulations done by ASC codes today at Livermore. Analytic EOSs are also still used, but have been superseded in many cases by tabular representations in LEOS (http://leos.llnl.gov). Numerous advanced constitutive models have been developed and implemented into ASC codes over the past 20 years. These newer models have more physics and better representations of material strength properties than their predecessors, and therefore more model coefficients. However, a material database of these coefficients is not readily available. Therefore incorporating these coefficients with those of the legacy models into a portable database that could be shared amongst codes would be most welcome. The goal of this paper is to describe the MatProp effort at LLNL to create such a database and associated access library that could be used by codes throughout the DOE complex and beyond. We have written an initial version of the MatProp database and access library and our DOE/ASC code ALE3D (Nichols et. al., UCRL-MA-152204) is able to import information from the database. The database, a link to which exists on the Sourceforge server at LLNL, contains coefficients for many materials and models (see Appendix), and includes material parameters in the following categories--flow stress, shear modulus, strength, damage, and equation of state. Future versions of the Matprop database and access library will include the ability to read and write material descriptions that can be exchanged between codes. It will

  6. Detection of Fusarium spp. and Trichoderma spp. and antagonism of Trichoderma sp. in soybean under no-tillage

    OpenAIRE

    Paola Mendes Milanesi; Elena Blume; Marlove Fátima Brião Muniz; Lia Rejane Silveira Reiniger; Zaida Inês Antoniolli; Emanuele Junges; Manoeli Lupatini

    2013-01-01

    This study aimed i) to quantify the occurrence of Fusarium spp. and Trichoderma spp. in rhizospheric soil, with and without symptoms of Sudden Death Syndrome (SDS) in eight soybean genotypes; ii) morphologically identify isolates of Fusarium spp. from roots with SDS; iii) evaluate the antagonism between Trichoderma spp. and Fusarium spp. isolates from rhizospheric soil and roots from with and without SDS, respectively; and iv) characterize through the ITS1-5.8S-ITS2 region of rDNA the isolate...

  7. Serological Evidence of Exposure to Leptospira spp. in Veterinary Students and Other University Students in Trinidad and Tobago

    Directory of Open Access Journals (Sweden)

    Ambrose James

    2013-01-01

    Full Text Available The study compared the serological evidence of leptospirosis in 212 students in four schools (veterinary, dental, advanced nursing education and pharmacy of the University of the West Indies (UWI, by testing for IgG immunoglobulins to Leptospira spp. using the enzyme-linked immunosorbent assay (ELISA and the microscopic agglutination test (MAT. Overall, of 212 students tested by the ELISA, 12 (5.7% and 31 (14.6% were positive and borderline, respectively. Amongst the 113 veterinary students 11 (9.7% and 19 (16.8% were seropositive and borderline respectively compared with nonveterinary students with corresponding values of 1 (1.0% and 12 (12.1%. The frequency of serological evidence of leptospirosis by the ELISA was statistically significantly (; higher in veterinary students, 26.5% (30 of 113 than in nonveterinary students, 13.1% (13 of 99. By the MAT, the seropositivity for leptospirosis was similar for veterinary students, 7.1% (8 of 113 and nonveterinary students, 7.1% (7 of 99. For veterinary students, the prevalent infecting serovar was Icterohaemorrhagiae Copenhageni while amongst nonveterinary students, the prevalent serovar was Australis Rachmati. Being a veterinary student was the only risk factor that was significantly associated with Leptospira infection indicating that veterinary students need to be cognizant and to practise preventive measures for leptospirosis.

  8. Characterization of Trichodesmium spp. by Genetic Techniques

    OpenAIRE

    Orcutt, K.M.; Rasmussen, U.; Webb, E.A.; Waterbury, J B; K. Gundersen; Bergman, B

    2002-01-01

    The genetic diversity of Trichodesmium spp. from natural populations (off Bermuda in the Sargasso Sea and off North Australia in the Arafura and Coral Seas) and of culture isolates from two regions (Sargasso Sea and Indian Ocean) was investigated. Three independent techniques were used, including a DNA fingerprinting method based on a highly iterated palindrome (HIP1), denaturing gradient gel electrophoresis of a hetR fragment, and sequencing of the internal transcribed spacer (ITS) of the 16...

  9. Trypanosoma spp. in Swedish game animals

    OpenAIRE

    NEUMÜLLER, Magnus; Nilsson, Kenneth; Påhlson, Carl

    2012-01-01

    Serum and blood samples from 36 game animals, shot during the hunting seasons 2007-2009, were collected and analyzed for the presence of Trypanosoma spp. by three methods: isolation, polymerase chain reaction (PCR), and serology. Only fissiped animals were included, four different ruminants and wild boar. Trypanosomes could be isolated from two of the animals, and eight had detectable parasite DNA. Seven animals had high titers of anti-trypanosoma IgG antibodies. The two isolated strains, one...

  10. Characterization of Brevibacterium spp. from clinical specimens.

    OpenAIRE

    Gruner, E; Pfyffer, G E; von Graevenitz, A

    1993-01-01

    Nonfermenting coryneform bacteria identified as Brevibacterium spp. were isolated from routine clinical specimens. Four strains were derived from peritoneal fluid and has presumably been involved in the pathogenesis of continuous ambulatory peritoneal dialysis peritonitis. Another five isolates most probably represented skin contaminants. Cell wall and lipid analyses confirmed the genus identification. Strains in this taxon are difficult to distinguish from other biochemically inactive and no...

  11. Active ingredient-containing chitosan/polycaprolactone nonwoven mats: Characterizations and their functional assays

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Meng-Yi, E-mail: mybai@mail.ntust.edu.tw [Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan, ROC (China); Adjunct appointment to the Department of Biomedical Engineering, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Chou, Tz-Chong, E-mail: tcchou@ms5.hinet.net [Department of Biomedical Engineering, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Tsai, Jie-Chang; Yang, Hui-Ching [Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan, ROC (China)

    2013-01-01

    This study demonstrates a facile method developed to generate a chitosan/polycaprolactone (CS/PCL) nonwoven mat. All nonwoven mats are composed of microfibers with an average diameter of 2.51 {+-} 0.69 {mu}m. The X-ray photoelectron spectroscopy data indicate that positively charged nitrogen was generated on the surface of the mats after undergoing CS coating. By using a non-contacting electrostatic voltmeter, we determined that the nonwoven mats exhibited a positive potential and the charge density of the CS/PCL nonwoven mat was in proportion to the thickness of the CS overlayer. Moreover, platelet aggregation and anti-bacterial ability were enhanced by the CS/PCL nonwoven mat as compared to that of PCL nonwoven mat alone. The enhancements of the CS/PCL nonwoven mat on platelet aggregation are further promoted by incorporating a 1 mM calcium ion in its CS overlayer. We also find that the addition of tea tree oil in the CS overlayer significantly inhibited LPS-induced nitrite formation in Raw 264.7 macrophages. In conclusion, our CS/PCL nonwoven mat possesses pharmacological effects including an increase of platelet aggregation, anti-bacterial, anti-adhesive, and anti-inflammatory activities. The performance of this CS/PCL nonwoven mat can be further promoted by incorporating active compounds to exert therapeutic effects in wound healing. Highlights: Black-Right-Pointing-Pointer We develop a facile method to generate active ingredient-containing CS/PCLNM. Black-Right-Pointing-Pointer Our CS/PCLNM possesses superior mechanical strength, compared to CS-blended PCL nanofibers. Black-Right-Pointing-Pointer We prove that our prepared CS/PCLNM possesses several pharmacological properties Black-Right-Pointing-Pointer The functional performances of CS/PCLNM are enhanced by incorporation of active compounds. Black-Right-Pointing-Pointer Incorporation of 1 mM of calcium ions or 100 {mu}L of TTO into the CS overlayer of CS/PCLNM is the optimum dose.

  12. Active ingredient-containing chitosan/polycaprolactone nonwoven mats: Characterizations and their functional assays

    International Nuclear Information System (INIS)

    This study demonstrates a facile method developed to generate a chitosan/polycaprolactone (CS/PCL) nonwoven mat. All nonwoven mats are composed of microfibers with an average diameter of 2.51 ± 0.69 μm. The X-ray photoelectron spectroscopy data indicate that positively charged nitrogen was generated on the surface of the mats after undergoing CS coating. By using a non-contacting electrostatic voltmeter, we determined that the nonwoven mats exhibited a positive potential and the charge density of the CS/PCL nonwoven mat was in proportion to the thickness of the CS overlayer. Moreover, platelet aggregation and anti-bacterial ability were enhanced by the CS/PCL nonwoven mat as compared to that of PCL nonwoven mat alone. The enhancements of the CS/PCL nonwoven mat on platelet aggregation are further promoted by incorporating a 1 mM calcium ion in its CS overlayer. We also find that the addition of tea tree oil in the CS overlayer significantly inhibited LPS-induced nitrite formation in Raw 264.7 macrophages. In conclusion, our CS/PCL nonwoven mat possesses pharmacological effects including an increase of platelet aggregation, anti-bacterial, anti-adhesive, and anti-inflammatory activities. The performance of this CS/PCL nonwoven mat can be further promoted by incorporating active compounds to exert therapeutic effects in wound healing. Highlights: ► We develop a facile method to generate active ingredient-containing CS/PCLNM. ► Our CS/PCLNM possesses superior mechanical strength, compared to CS-blended PCL nanofibers. ► We prove that our prepared CS/PCLNM possesses several pharmacological properties ► The functional performances of CS/PCLNM are enhanced by incorporation of active compounds. ► Incorporation of 1 mM of calcium ions or 100 μL of TTO into the CS overlayer of CS/PCLNM is the optimum dose.

  13. Fermentability of an enzymatically modified solubilised potato polysaccharide (SPP)

    DEFF Research Database (Denmark)

    Olesen, M.; Gudmand-Høyer, E.; Bergsøe, Merete Norsker;

    1998-01-01

    : Seven healthy volunteers ingested in random order on seven different days: 20 g SPP; bread made of 180 g wheat flour served with 20 g raw SPP; bread baked of 180 g wheat flour and 20 g SPP; bread made from 180 g what flour; 20 g lactulose; 20 g oat bran; and 20 g wheat bran. The hydrogen breath test was...... used to evaluate oro-coecal transit time (OCTT) and fermentation. RESULTS: Fermentation of SPP yielded a measurable increase in end-expiratory H2. The total incremental increase in end expiratory H2 due to SPP was unaffected of whether SPP was served alone, as the raw flour served with bread, or baked...... into bread. The OCTT for raw SPP was significantly delayed compared to lactulose (P = 0.01). The OCTT for SPP baked into bread was significantly delayed compared to raw SPP (P = 0.01), indicating that SPP may be used as a marker of oro-coecal transit time for as well the fluid phase as the solid phase...

  14. Relationship between Fusarium spp. diversity and mycotoxin contents of mature grains in southern Belgium.

    Science.gov (United States)

    Hellin, Pierre; Dedeurwaerder, Géraldine; Duvivier, Maxime; Scauflaire, Jonathan; Huybrechts, Bart; Callebaut, Alfons; Munaut, Françoise; Legrève, Anne

    2016-07-01

    Over a 4-year period (2010-13), a survey aiming at determining the occurrence of Fusarium spp. and their relations to mycotoxins in mature grains took place in southern Belgium. The most prevalent species were F. graminearum, F. avenaceum, F. poae and F. culmorum, with large variations between years and locations. An even proportion of mating type found for F. avenaceum, F. culmorum, F. cerealis and F. tricinctum is usually a sign of ongoing sexual recombination. In contrast, an unbalanced proportion of mating type was found for F. poae and no MAT1-2 allele was present in the F. langsethiae population. Genetic chemotyping indicates a majority of deoxynivalenol (DON)-producing strains in F. culmorum (78%, all 3-ADON producers) and F. graminearum (95%, mostly 15-ADON producers), while all F. cerealis strains belong to the nivalenol (NIV) chemotype. Between 2011 and 2013, DON, NIV, enniatins (ENNs) and moniliformin (MON) were found in each field in various concentrations. By comparison, beauvericin (BEA) was scarcely detected and T-2 toxin, zearalenone and α- and β-zearalenols were never detected. Principal component analysis revealed correlations of DON with F. graminearum, ENNs and MON with F. avenaceum and NIV with F. culmorum, F. cerealis and F. poae. BEA was associated with the presence of F. tricinctum and, to a lesser extent, with the presence of F. poae. The use of genetic chemotype data revealed that DON concentrations were mostly influenced by DON-producing strains of F. graminearum and F. culmorum, whereas the concentrations of NIV were influenced by the number of NIV-producing strains of both species added to the number of F. cerealis and F. poae strains. This study emphasises the need to pay attention to less-studied Fusarium spp. for future Fusarium head blight management strategies, as they commonly co-occur in the field and are associated with a broad spectrum of mycotoxins. PMID:27181458

  15. Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake.

    Science.gov (United States)

    Jungblut, Anne D; Hawes, Ian; Mackey, Tyler J; Krusor, Megan; Doran, Peter T; Sumner, Dawn Y; Eisen, Jonathan A; Hillman, Colin; Goroncy, Alexander K

    2016-01-01

    Lake Fryxell is a perennially ice-covered lake in the McMurdo Dry Valleys, Antarctica, with a sharp oxycline in a water column that is density stabilized by a gradient in salt concentration. Dissolved oxygen falls from 20 mg liter(-1) to undetectable over one vertical meter from 8.9- to 9.9-m depth. We provide the first description of the benthic mat community that falls within this oxygen gradient on the sloping floor of the lake, using a combination of micro- and macroscopic morphological descriptions, pigment analysis, and 16S rRNA gene bacterial community analysis. Our work focused on three macroscopic mat morphologies that were associated with different parts of the oxygen gradient: (i) "cuspate pinnacles" in the upper hyperoxic zone, which displayed complex topography and were dominated by phycoerythrin-rich cyanobacteria attributable to the genus Leptolyngbya and a diverse but sparse assemblage of pennate diatoms; (ii) a less topographically complex "ridge-pit" mat located immediately above the oxic-anoxic transition containing Leptolyngbya and an increasing abundance of diatoms; and (iii) flat prostrate mats in the upper anoxic zone, dominated by a green cyanobacterium phylogenetically identified as Phormidium pseudopriestleyi and a single diatom, Diadesmis contenta. Zonation of bacteria was by lake depth and by depth into individual mats. Deeper mats had higher abundances of bacteriochlorophylls and anoxygenic phototrophs, including Chlorobi and Chloroflexi. This suggests that microbial communities form assemblages specific to niche-like locations. Mat morphologies, underpinned by cyanobacterial and diatom composition, are the result of local habitat conditions likely defined by irradiance and oxygen and sulfide concentrations. PMID:26567300

  16. Potential of Winkler type platform models for SSI problems considering flexibility of base mat

    International Nuclear Information System (INIS)

    Highlights: • Base mat's flexibility affects different seismic response parameters in different ways. • The most sensitive are the internal seismic response forces in the base mat itself. • Vertical response accelerations in the centers of the rooms are sensitive too. • Shaped Winkler model generally gives better results than the conventional flat one. • Even shaped Winkler model cannot reproduce the response in two sensitive formats. -- Abstract: Linear soil-structure interaction (SSI) analysis seems to be well understood nowadays and can be performed, for example, by convenient combined asymptotic method (CAM). However, CAM is asymptotically accurate for rigid base mats only – this is a limitation. So, the additional research is needed to find out (a) what is the impact of the base mat's flexibility to the seismic response; (b) how can one account for this impact using the conventional tools. In the first part of the paper a sample “wave” solution is obtained in the frequency domain using SASSI2000 code, without CAM at all. Different formats of the seismic response (e.g., in-structure response spectra, soil-structure interaction forces, in-structure internal forces) have proved to have different sensitivity to the base mat's flexibility. In the second part of the paper this wave solution is a benchmark for the different “platform” models with “soil” springs and dashpots distributed over the base mat (this is a broad definition of Winkler type model). Different shapes of distribution, starting from the conventional Winkler's flat shape and up to the “optimal” shape, are compared to each other in the second part of the paper. It is shown that even the most advanced “shaped” models of the Winkler type are limited in their ability to reproduce seismic response in the most sensitive format – the internal forces in the mat. This is the result of (a) local nature of Winkler's model, and (b) frequency independence of its’ parameters

  17. The Epsomitic Phototrophic Microbial Mat of Hot Lake, Washington. Community Structural Responses to Seasonal Cycling

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, Stephen R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stegen, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Renslow, Ryan S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cole, Jessica K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dohnalkova, Alice [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tremblay, Julien [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singh, Kanwar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Malfatti, Stephanie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chen, Feng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tringe, Susannah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Beyenal, Haluk [Washington State Univ., Pullman, WA (United States); Fredrickson, Jim K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-11-13

    Phototrophic microbial mats are compact ecosystems composed of highly interactive organisms in which energy and element cycling take place over millimeter-to-centimeter-scale distances. Although microbial mats are common in hypersaline environments, they have not been extensively characterized in systems dominated by divalent ions. Hot Lake is a meromictic, epsomitic lake that occupies a small, endorheic basin in north-central Washington. The lake harbors a benthic, phototrophic mat that assembles each spring, disassembles each fall, and is subject to greater than tenfold variation in salinity (primarily Mg2+ and SO2-4) and irradiation over the annual cycle. We examined spatiotemporal variation in the mat community at five time points throughout the annual cycle with respect to prevailing physicochemical parameters by amplicon sequencing of the V4 region of the 16S rRNA gene coupled to near-full-length 16S RNA clone sequences. The composition of these microbial communities was relatively stable over the seasonal cycle and included dominant populations of Cyanobacteria, primarily a group IV cyanobacterium (Leptolyngbya), and Alphaproteobacteria (specifically, members of Rhodobacteraceae and Geminicoccus). Members of Gammaproteobacteria (e.g., Thioalkalivibrio and Halochromatium) and Deltaproteobacteria (e.g., Desulfofustis) that are likely to be involved in sulfur cycling peaked in summer and declined significantly by mid-fall, mirroring larger trends in mat community richness and evenness. Phylogenetic turnover analysis of abundant phylotypes employing environmental metadata suggests that seasonal shifts in light variability exert a dominant influence on the composition of Hot Lake microbial mat communities. The seasonal development and organization of these structured microbial mats provide opportunities for analysis of the temporal and physical dynamics that feed back to community function.

  18. UV B-induced vertical migrations of cyanobacteria in a microbial mat

    International Nuclear Information System (INIS)

    Exposure to moderate doses of UV B (0.35 to 0.79 W m-2 s-1 or 0.98 to 2.2 μmol of photons m-2 s-1 at 310 nm) caused the surface layers of microbial mats from Solar Lake, Sinai, Egypt, to become visibly lighter green. Concurrent with the color change were rapid and dramatic reductions in gross photosynthesis and in the resultant high porewater oxygen concentrations in the surface layers of the mats. The depths at which both maximum gross photosynthesis and maximum oxygen concentrations occurred were displaced downward. In contrast, gross photosynthesis in the deeper layers of the mats increased in response to UV B incident upon the surface. The cessation of exposure to UV B partially reversed all of these changes. Taken together, these responses suggest that photoautotrophic members of the mat community, most likely the dominant cyanobacterium Microcoleus chthonoplastes, were migrating in response to the added UV B. The migration phenomenon was also observed in response to increases in visible radiation and UV A, but UV B was ca. 100-fold more effective than visible radiation and ca. 20-fold more effective than UV A in provoking the response. Migrating microorganisms within this mat are apparently able to sense UV B directly and respond behaviorally to limit their exposure to UV. Because of strong vertical gradients of light and dissolved substances in microbial mats, the migration and the resultant vertical redistribution of photosynthetic activity have important consequences for both the photobiology of the cyanobacteria and the net primary productivity of the mat ecosystem

  19. Existence of Cryptosporidium spp. oocysts and Giardia spp. cysts in well water in Nineveh governorate

    OpenAIRE

    R. G. Mohammad

    2011-01-01

    The study included examination of 110 water samples from well distributed in Mosul city and few towns and villages around it from May 2009 to March 2010 for detection of Cryptosporidium spp oocysts and Giardia spp cysts in well water. The results revealed that the prevalence of Cryptosporidium oocysts was 16.36% while the prevalence of Giardia cysts was 12.72%. The percentages of prevalence with Cryptosporidium and Giardia were in high rate in Bartilla and some villages around it 20% for Cryp...

  20. Standardization of a quantification method for Salmonella spp. and Shigella spp. in specific liquid media

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Rivera

    2010-09-01

    Full Text Available Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs have yielded promising results. Escherichia coli (E. coli is customarily used as faecal bacterial indicator to determine the efficiency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella  spp. and Salmonella  spp. Additionally, the viable non-culturable (VNC state yields bacteria which are not detectable on many culture media. Objective: The main objective is to standardize a method for counting Salmonella  spp. and Shigella  spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO. Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella  spp. and Shigella  spp. Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth. Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP and EE broths, respectively. To some extent, this suggests an additional confirmative method when using the

  1. Standardization of a quantification method for Salmonella spp. and Shigella spp. in specific liquid media

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Rivera

    2010-03-01

    Full Text Available Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs have yielded promising results. Escherichia coli (E. coli is customarily used as faecal bacterial indicator to determine the efficiency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella spp. and Salmonella spp. Additionally, the viable non-culturable (VNC state yields bacteria which are not detectable on many culture media.Objective: The main objective is to standardize a method for counting Salmonella spp. and Shigella spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO.Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella spp. and Shigella spp.Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth.Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP and EE broths, respectively. To some extent, this suggests an additional confirmative method when using the EE® broth

  2. Resistência ao glyphosate em biótipos de buva (Conyza spp. das regiões oeste e sudoeste do Paraná Resistance to glyphosate in Conyza spp. biotypes in western and southwestern Parana, Brazil

    Directory of Open Access Journals (Sweden)

    M.M Trezzi

    2011-01-01

    Full Text Available A resistência ao glyphosate em biótipos de Conyza spp. em áreas de lavoura das regiões oeste e sudoeste do Paraná causa grandes dificuldades ao manejo e, consequentemente, problemas econômicos e ambientais. Este experimento objetivou determinar a existência de resistência ao herbicida glyphosate em biótipos de buva (Conyza spp. suspeitos, coletados em lavouras das regiões oeste e sudoeste do Paraná, comparando-os com biótipos suscetíveis. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 12 x 8 x 3. Os fatores consistiram de 12 biótipos de buva, doses de glyphosate (0, 100, 180, 324, 583, 1.050, 1.888 e 3.345 g ha-1 e épocas de avaliação para a variável controle (7, 14 e 21 dias após a aplicação. Para as variáveis matéria verde e matéria seca, o esquema fatorial utilizado foi o 12 x 8. As variáveis avaliadas foram controle visual, matéria verde, matéria seca, C50, GR50 e fator de resistência. A dose de 3.345 g glyphosate ha-1 foi a que apresentou maior nível de controle dos biótipos, porém o controle dos biótipos suspeitos não foi efetivo, necessitando de doses mais altas. Todos os biótipos de buva suspeitos de resistência ao glyphosate tiveram essa característica confirmada. Entretanto, constatou-se grande amplitude de fatores de resistência, o que caracteriza a variabilidade entre os biótipos resistentes. Essas informações poderão ser utilizadas no planejamento de estratégias de manejo das populações resistentes e na prevenção da ocorrência de novas áreas com buva resistente ao glyphosate.Glyphosate-resistant biotypes of Conyza spp. (hairy fleabane, horseweed in crop areas in the western and southwestern regions of the state of Paraná, Brazil, cause great management, economic, and environmental problems. This experiment aimed to determine the existence of horseweed biotypes resistant to glyphosate in the suspected populations collected from farms in western

  3. Prevalencia de anticuerpos anti-Leptospira spp. en personas con exposición laboral en el departamento del Tolima / Prevalence of anti-Leptospira spp. antibodies among people with occupational exposure in Tolima Department

    Directory of Open Access Journals (Sweden)

    Blanca L. Guzmán-Barragán

    2016-05-01

    Full Text Available Resumen Objetivo: estimar la prevalencia de anticuerpos IgM contra Leptospira spp., mediante el Ensayo de Inmunoabsorción Ligado a Enzimas (elisa, en la población de riesgo laboral de 8 municipios del Tolima. Metodología: se obtuvieron muestras de sangre de 261 empleados, las cuales fueron analizadas mediante la técnica de elisa para la detección de anticuerpos IgM anti-Leptospira spp., seguido de mat y serotipificación. Resultado: se estimó una seroprevalencia del 25,29%, con una seroreactividad mayor en trabajadores de plantas de beneficio animal (34,2%, recolección de residuos sólidos (27,1% y trabajadores de acueducto y alcantarillado (14,8%. La actividad en plantas de beneficio animal se identificó como factor de riesgo de Leptospira spp. (OR=1,86. Los serovares identificados fueron L. Bratislava (16, Ballum (5, Tarassovi (3, Hebdomadis (2, Sejroe (2 y Icterhemorragiae (1. El municipio de Libano presento el mayor porcentaje de positividad (36,96%, seguido de Espinal y Guamo con 28,57% cada uno. Discusión: la evaluación del sistema de vigilancia indicó deficiencia en recursos y debilidades de los profesionales de la salud al desconocer los procedimientos, investigación, diagnóstico y notificación de la enfermedad. Conclusiones: la leptospirosis está presente en poblaciones de riesgo laboral en el Tolima y se hace necesario abordar esta problemática en la población de otros municipios y los animales transmisores de la enfermedad. / Abstract Objective: to estimate the prevalence of IgM antibodies against Leptospira spp. Using the enzyme-linked immunosorbent assay (elisa in a population at occupational risk from 8 municipalities of the Tolima department, Colombia. Methodology: blood samples were collected from 261 employees and analyzed with the elisa technique to detect IgM and anti-Leptospira spp. antibodies. This was followed by mat and serotyping. Results: a seroprevalence of 25.29% was estimated, with higher

  4. The evolutionary trajectory of the mating-type (mat genes in Neurospora relates to reproductive behavior of taxa

    Directory of Open Access Journals (Sweden)

    Johannesson Hanna

    2008-04-01

    Full Text Available Abstract Background Comparative sequencing studies among a wide range of taxonomic groups, including fungi, have led to the discovery that reproductive genes evolve more rapidly than other genes. However, for fungal reproductive genes the question has remained whether the rapid evolution is a result of stochastic or deterministic processes. The mating-type (mat genes constitute the master regulators of sexual reproduction in filamentous ascomycetes and here we present a study of the molecular evolution of the four mat-genes (mat a-1, mat A-1, mat A-2 and mat A-3 of 20 Neurospora taxa. Results We estimated nonsynonymous and synonymous substitution rates of genes to infer their evolutionary rate, and confirmed that the mat-genes evolve rapidly. Furthermore, the evolutionary trajectories are related to the reproductive modes of the taxa; likelihood methods revealed that positive selection acting on specific codons drives the diversity in heterothallic taxa, while among homothallic taxa the rapid evolution is due to a lack of selective constraint. The latter finding is supported by presence of stop codons and frame shift mutations disrupting the open reading frames of mat a-1, mat A-2 and mat A-3 in homothallic taxa. Lower selective constraints of mat-genes was found among homothallic than heterothallic taxa, and comparisons with non-reproductive genes argue that this disparity is not a nonspecific, genome-wide phenomenon. Conclusion Our data show that the mat-genes evolve rapidly in Neurospora. The rapid divergence is due to either adaptive evolution or lack of selective constraints, depending on the reproductive mode of the taxa. This is the first instance of positive selection acting on reproductive genes in the fungal kingdom, and illustrates how the evolutionary trajectory of reproductive genes can change after a switch in reproductive behaviour of an organism.

  5. Consumption of Methane and CO_2 by Methanotrophic Microbial Mats from Gas Seeps of the Anoxic Black Sea

    OpenAIRE

    Treude, Tina; Orphan, Victoria; Knittel, Katrin; Gieseke, Armin; House, Christopher H.; Boetius, Antje

    2007-01-01

    The deep anoxic shelf of the northwestern Black Sea has numerous gas seeps, which are populated by methanotrophic microbial mats in and above the seafloor. Above the seafloor, the mats can form tall reef-like structures composed of porous carbonate and microbial biomass. Here, we investigated the spatial patterns of CH_4 and CO_2 assimilation in relation to the distribution of ANME groups and their associated bacteria in mat samples obtained from the surface of a large reef structure. A combi...

  6. Application of Indigenous Folk Wisdom Concerning the Management of Commercial Reed-Mat Production in Maha Sarakham Province, Thailand

    OpenAIRE

    Songkoon Chantachon

    2013-01-01

    A dying skill in a thriving economy, reed-mat production is fast losing its identity as a traditional Thai handicraft. This qualitative research analyzes how local wisdom is used in the management of commercial reed-mat production in Maha Sarakham Province, Thailand. Once-distinctive Thai reed-mats are now being mass-produced to cope with global demand, killing the economic viability of hand produced merchandise. This study identifies problems with materials, equipment, production process, pr...

  7. Biogeochemistry of hypersaline microbial mats illustrates the dynamics of modern microbial ecosystems and the early evolution of the biosphere

    Science.gov (United States)

    Des Marais, David J.

    2003-01-01

    Photosynthetic microbial mats are remarkably complete self-sustaining ecosystems at the millimeter scale, yet they have substantially affected environmental processes on a planetary scale. These mats may be direct descendents of the most ancient biological communities in which even oxygenic photosynthesis might have developed. Photosynthetic mats are excellent natural laboratories to help us to learn how microbial populations associate to control dynamic biogeochemical gradients.

  8. Russian Army Mat as a Code System Controlling Behaviour in the Russian army

    Directory of Open Access Journals (Sweden)

    Vadim Mikhailin

    2004-09-01

    Full Text Available This text is to be a shortened, restructured and based on somewhat another factological foundation version of my article “Russkii mat kak muzhskoi obstsennyi kod: problema proiskhozhdeniia i evoliutsiia statusa”, published in # 43 of Novoe Literaturnoe Obozrenie. Tracing the genesis of mat to the specific modes of behaviour, peculiar to the archaic male warrior bands, I’m going to show that the military milieu (and some other, structurally close to it social strata, has always been – and remain – absolutely adequate for the mat speaking. Moreover, mat has always carried on within these strata rather specific function connected with creating of one’s identity as a military, and its use offers various and sometimes the only possible means of impact at one’s equal or subordinate (or even superior. As a matter of fact, mat is a basis for a whole code system, controlling different military behaviour practices. The problems of the freshers’ adaptation and of the national specificities in the late Soviet and modern Russian army are to be considered with special respect.

  9. Jet Shaping Nanofibers and the Collection of Nanofiber Mats in Electrospinning

    Institute of Scientific and Technical Information of China (English)

    Xinwei WANG; Jin CAO; Zuming HU; Wanlian PAN; Zhaofeng LIU

    2006-01-01

    Electrospinning is an effective way to produce nanofibers. Theconcentration or the corresponding viscosity of the spin solution is one of the most important variables to control the fiber morphology in electrospinning. Jet shaping nanofibers might be divided in two operating modes for different solution viscosity: split thinning and single thinning. From the analysis of jet single thinning, an equation to calculate the velocity of nanofibers depositing on the collector was educed and it was found that the velocity range was very different from the reported result. For the electrospun mats obtained from low solution concentration, the split is observed by scanning electron microscopy (SEM) images. On the other hand, the beads formation in the nanofiber mats can be explained well by jet splitting. The arrangement of nanofibers in the mats is related to the methods of collection, and the cylinder collector gets more ordered mats. This result is proved by so-called break strengths testing and SEM images of the mats obtained from different methods of collection.

  10. Rapid Reactivation of Cyanobacterial Photosynthesis and Migration upon Rehydration of Desiccated Marine Microbial Mats

    KAUST Repository

    Chennu, Arjun

    2015-12-24

    Desiccated cyanobacterial mats are the dominant biological feature in the Earth’s arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors, and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 min after rehydration chlorophyll a concentrations increased 2–5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min–48 h) involved migration of the reactivated cyanobacteria toward the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and marine origin. However, the response of upward migration and its triggering factor appear to be mat-specific and likely linked to other factors.

  11. Arc_Mat: a Matlab-based spatial data analysis toolbox

    Science.gov (United States)

    Liu, Xingjian; Lesage, James

    2010-03-01

    This article presents an overview of Arc_Mat, a Matlab-based spatial data analysis software package whose source code has been placed in the public domain. An earlier version of the Arc_Mat toolbox was developed to extract map polygon and database information from ESRI shapefiles and provide high quality mapping in the Matlab software environment. We discuss revisions to the toolbox that: utilize enhanced computing and graphing capabilities of more recent versions of Matlab, restructure the toolbox with object-oriented programming features, and provide more comprehensive functions for spatial data analysis. The Arc_Mat toolbox functionality includes basic choropleth mapping; exploratory spatial data analysis that provides exploratory views of spatial data through various graphs, for example, histogram, Moran scatterplot, three-dimensional scatterplot, density distribution plot, and parallel coordinate plots; and more formal spatial data modeling that draws on the extensive Spatial Econometrics Toolbox functions. A brief review of the design aspects of the revised Arc_Mat is described, and we provide some illustrative examples that highlight representative uses of the toolbox. Finally, we discuss programming with and customizing the Arc_Mat toolbox functionalities.

  12. Bacterial Diversity in Microbial Mats and Sediments from the Atacama Desert.

    Science.gov (United States)

    Rasuk, Maria Cecilia; Fernández, Ana Beatriz; Kurth, Daniel; Contreras, Manuel; Novoa, Fernando; Poiré, Daniel; Farías, María Eugenia

    2016-01-01

    The Atacama Desert has extreme environmental conditions that allow the development of unique microbial communities. The present paper reports the bacterial diversity of microbial mats and sediments and its mineralogical components. Some physicochemical conditions of the water surrounding these ecosystems have also been studied trying to determine their influence on the diversity of these communities. In that way, mats and sediments distributed among different hypersaline lakes located in salt flats of the Atacama Desert were subjected to massive parallel sequencing of the V4 region of the 16S rRNA genes of Bacteria. A higher diversity in sediment than in mat samples have been found. Lakes that harbor microbial mats have higher salinity than lakes where mats are absent. Proteobacteria and/or Bacteroidetes are the major phyla represented in all samples. An interesting item is the finding of a low proportion or absence of Cyanobacteria sequences in the ecosystems studied, suggesting the possibility that other groups may be playing an essential role as primary producers in these extreme environments. Additionally, the large proportion of 16S rRNA gene sequences that could not be classified at the level of phylum indicates potential new phyla present in these ecosystems. PMID:26224164

  13. Investigation of Water Permeability of Thermoplastic Polyurethane (TPU Electrospun Porous Mat

    Directory of Open Access Journals (Sweden)

    Aušra BANUŠKEVIČIŪTĖ

    2013-05-01

    Full Text Available The aim of this study is to form thermoplastic polyurethane (TPU mats by electrospinning process on knitted and woven materials, and to determine the water permeability of textile materials before and after mat has been formed on them. TPU granules were dissolved in a mixture of dimethylformamide (DMF and tetrahydrofuran (THF (1:1, w/w solvents. TPU solution of 3 wt.% concentration was prepared. TPU mats were electrospun by "NanospiderTM“, the applied voltage was 65 kV. Selected textile materials were knitted and woven cotton fabrics. Textile materials were covered by 1, 2, 3 and 4 layers of TPU mats. For the experiment four textile support materials such as fleece knitted fabric and three twill weave cotton fabrics were chosen. The water permeability was determined by a water drop method measuring the area of water drop. It was determined that the greater the number of layers on the textile materials with TPU electrospun fiber the thicker will be the mat. The greater number of layers decreases the expansion of water drop area on the textile material.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4435

  14. Rapid reactivation of cyanobacterial photosynthesis and migration upon rehydration of desiccated marine microbial mats

    Directory of Open Access Journals (Sweden)

    Arjun eChennu

    2015-12-01

    Full Text Available Desiccated cyanobacterial mats are the dominant biological feature in the Earth's arid zones. While the response of desiccated cyanobacteria to rehydration is well documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 minutes after rehydration chlorophyll a concentrations increased 2-5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min – 48 h involved migration of the reactivated cyanobacteria towards the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and aquatic origin. However the response of upward migration and its triggering factor appears to be mat-specific and likely linked to other factors.

  15. Enhancement of Rice Seed Germination and Vigour by Trichoderma spp.

    OpenAIRE

    Febri Doni; I. Anizan; C.M.Z. Che Radziah; Ahmad Hilmi Salman; Muhammad Hidayat Rodzihan; Wan Mohtar Wan Yusoff

    2014-01-01

    The present study was undertaken to examine the effectiveness of Trichoderma spp. to enhance rice germination and vigour. An in vitro experiment was carried out to assess the effect of seven isolates of Trichoderma spp. in enhancing rice germination and vigour. The results showed that all isolates of Trichoderma spp. significantly increased rice seedling growth, germination rate, vigour index and speed of germination with sp., SL2 showing the greatest increase in all the four parameters. Tric...

  16. Screening of Gibberellic Acid Production by Pseudomonas SPP

    International Nuclear Information System (INIS)

    The microbial gibberellic acid (GA3) production of Pseudomonas spp., was studied and qualitatively indentified by UV spectrophotometer. 20 strains of Pseudomonas spp., were isolated and screened the gibberellic acid productivily in King's B medium. Among them, only four strains can produce microbial gibberellic acid. The Rf values and colour appearance under UV were the same as authentic gibberellic acid. Moreover, the gibberellic acid producer strains were identified as Pseudomonas spp., by cultural, biochemical and drug sensitivity pattern.

  17. New, simple medium for selective, differential recovery of Klebsiella spp.

    OpenAIRE

    Tomás, J. M.; Ciurana, B; Jofre, J T

    1986-01-01

    A highly selective, differential medium for the enumeration and isolation of Klebsiella spp. was developed. With pure cultures, 100% recovery of Klebsiella spp. was observed. Recovery of Klebsiella spp. on MacConkey-inositol-potassium tellurite (MCIK) agar was as good as or better than on MacConkey-inositol-carbenicillin agar either with pure cultures or environmental samples. Recovery and percent colony confirmation with MCIK agar were greater and easier to obtain than for other proposed Kle...

  18. Cryptosporidium Spp. Infection in Human and Domestic Animals

    OpenAIRE

    Sh Farnia; Babaei, Z; Sh Maraghi; Mohebali, M; SM Heidarnegadi; A Bairami; M Rezaeian

    2012-01-01

    Background: Cryptosporidium spp. is a coccidian parasite infected humans and animals. Prevalence rate of Cryptosporidium spp. infection associated with is some parameters such as sampling, age, season, country and contact to domestic animals. This study aimed to determine Cryptosporidium spp. Infection in humans and some animals in rural areas of Shushtar district from Khuzestan Province, south- west of Iran.Methods: In this study, Stool specimens were randomly collected from 45 cattle , 8 bu...

  19. Occurrence of Giardia and Cryptosporidium spp. in Surface Water Supplies

    OpenAIRE

    LeChevallier, M W; Norton, W D; Lee, R. G.

    1992-01-01

    Giardia and Cryptosporidium levels were determined by using a combined immunofluorescence test for source waters of 66 surface water treatment plants in 14 states and 1 Canadian province. The results showed that cysts and oocysts were widely dispersed in the aquatic environment. Giardia spp. were detected in 81% of the raw water samples. Cryptosporidium spp. were found in 87% of the raw water locations. Overall, Giardia or Cryptosporidium spp. were detected in 97% of the raw water samples. Hi...

  20. Increased Prevalence of Trichinella spp., Northeastern Germany, 2008

    OpenAIRE

    Pannwitz, Gunter; Mayer-Scholl, Anne; Balicka-Ramisz, Aleksandra; Nöckler, Karsten

    2010-01-01

    In 2008, a Trichinella spp. outbreak occurred on a small family-owned pig farm in Mecklenburg–Western Pomerania in northeastern Germany. To obtain epidemiologic information on this outbreak, we determined that after 2005 the prevalence of Trichinella spp. in wild boars has increased in this region of Germany. We discuss the potential role of the raccoon dog in the increase in Trichinella spp. prevalence in the sylvatic cycle in this region. We believe that this increase could pose a threat to...

  1. Electrospun poly(l-lactide)/zein nanofiber mats loaded with Rana chensinensis skin peptides for wound dressing.

    Science.gov (United States)

    Zhang, Mei; Li, Xueqi; Li, Siming; Liu, Yongjia; Hao, Linlin

    2016-09-01

    Electrospun nanofiber mats can display impressive performance as an ideal wound dressing. In this study, poly(l-lactide)(PLLA)/zein nanofiber mats loaded with Rana chensinensis skin peptides (RCSPs) were successfully produced by two different electrospinning techniques, blend and coaxial, with the goal of developing a wound dressing material. The nanofiber mats were investigated by environmental scanning electron microscope (ESEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), water contact angle, mechanical tests and cell viability. The resulting nanofiber mats exhibited smooth surfaces, tiny diameters and different cross-sectional shapes from pure PLLA and zein nanofibers. The FTIR result showed that PLLA, zein and RCSPs were well dispersed, without chemical interactions. Compared with coaxial nanofiber mats, blending zein-RCSPs with PLLA enhanced hydrophilicity but decreased mechanical properties. Adding RCSPs into the electrospun nanofibers significantly improved the mechanical properties of the mats. Cell viability studies with human foreskin fibroblasts demonstrated that cell growth on PLLA/zein-RCSPs nanofiber mats was significantly higher than that on PLLA/zein nanofiber mats. The results indicate that nanofiber mats containing RCSPs are potential candidates for wound dressing. PMID:27432415

  2. Índice de área foliar, coeficiente de extinção luminosa e acúmulo de forragem em pastagens de Cynodon spp. sob lotação contínua

    OpenAIRE

    Fagundes Jailson Lara; Silva Sila Carneiro da; Pedreira Carlos Guilherme Silveira; Carnevalli Roberta Aparecida; Carvalho Carlos Augusto Brandão de; Sbrissia Andre Fisher; Pinto Luis Felipe de Moura

    2001-01-01

    Avaliou-se o índice de área foliar, o coeficiente de extinção luminosa e o acúmulo de matéria seca em três cultivares de Cynodon spp. (Tifton 85, Florakirk e Coastcross) submetidas a quatro intensidades de pastejo (5, 10, 15 e 20 cm) por ovinos em regime de lotação contínua. O delineamento experimental utilizado foi o de blocos completos casualizados, com quatro repetições, em parcelas subdivididas, tendo na parcela as cultivares, e na subparcela, as intensidades de pastejo. Os maiores valore...

  3. Isolamento de Pasteurella spp. e Vibrio spp. em robalos (Dicentrarchus labrax: susceptibilidade a diferentes grupos de antibióticos

    Directory of Open Access Journals (Sweden)

    Saavedra M.J.

    2004-01-01

    Full Text Available The most frequent infectious diseases that affect fish are those of bacterial origin. In European sea bass fish farms (Dicentrarchus labrax are included Vibrio spp., Pasteurella piscicida and Myxobacter spp. In addition to these, it is also possible to find, although lesser frequently, other pathogenic agents such as Pseudomonas spp., Aeromonas spp., Staphylococcus epidermis, Streptococcus spp. and Enterobacter spp. The presence of these micro-organisms in fish farms contributes for a significant decrease in fish production and subsequent loss of profitability in these aquaculture units. The use of antibiotics may therefore be necessary as a prophylactic measure although their systematic utilization leads to the development of strains of antibiotic resistant bacteria. Bearing that in mind, a survey was conducted on the susceptibility of isolated strains of bacteria found in juvenile European sea bass. It was concluded that chloranphenicol and tetracycline are two important antibiotic alternatives for therapy against isolated bacterial agents.

  4. Seroprevalence of Neospora Spp. in Horses in North East of Iran

    Directory of Open Access Journals (Sweden)

    MH Hosseini

    2011-06-01

    Full Text Available Background: Neospora caninum, an obligate intracellular protozoan parasite, is recognized as a major cause of abortion in cattle, while limited information is presently available on the seropreva­lence of Neospora antibodies in horses' worldwide .The aim of the present study was to de­termine serologic prevalence of Neospora infection in horses in Iran.Methods: Sera from 150 horses from Mashhad suburb in Razavi Khorasan Province, northeast Iran were examined for antibodies to Neospora spp. using Neospora modified direct agglutina­tion test (N-MAT.Results: Antibodies to this parasite were detected in 45 (30% of the examined serum samples. Thirty four percent of the samples had titer of 1:40 while then reduced to 30% when 1:80 serum dilution was applied as significant cut off titer.Conclusion: This study is the first investigation carried out on the Neospora in horses in Iran and indi­cates that horses in Iran are exposed to this parasite.

  5. Anti-Leptospira spp. antibodies in captive animals in Paraíba State

    Directory of Open Access Journals (Sweden)

    Arthur Brasil

    2013-12-01

    Full Text Available The aim of this survey was to verify the occurrence of anti-Leptospira spp. antibodies in captive animals in the Parque Zoobotânico Arruda Câmara, João Pessoa, Paraíba State, Northeastern Brazil. Blood samples were collected from 49 animals: 26 mammals of the species Sapajus libidinosus, Cebus flavius, Saimiri sciureu, Coendu sp., Pseudalopex vetulus, Leopardus pardalis, Leopardus tigrinus, Galactitis vitata, Eira barbara, Nasua nasua, Tayassu tajacu and Ratus norvegicus; 10 birds of the species Penelope jacucaca, Pavo cristatus, Anodorhynchus hyacinthinus, Ara chlorothpterus, Pionites leucogaster, Polyborus plancus, Geranoaetus melanoleucus and Urubitinga urubitinga; and 13 reptiles of the species Caiman latirostris, Paleosuchus trigonatus, Caiman crocodilus, Tupinabis merinae, Tupinambis teguixin, Boa constrictor, Corallus hortulanus, Python molurus, Bufocephala vanderhaegei, Geochelone denticulata and Geochelone carboraria. Sera were examined by the microscopic agglutination teste (MAT using 24 serovars as antigens and cut-off point of 1:100. One ocelot (Leopardo pardalis presented positive reaction for the Icterohaemorrhagiae serovar with titer of 100, however, it did not show any clinical sign of the infection. Sinantropic rodents are the main reservoirs of this serovar, which suggests the need of maintenance and continuous evaluation of rodent control programs.

  6. Medicinal leech therapy and Aeromonas spp. infection.

    Science.gov (United States)

    Verriere, B; Sabatier, B; Carbonnelle, E; Mainardi, J L; Prognon, P; Whitaker, I; Lantieri, L; Hivelin, M

    2016-06-01

    While the use of medicinal leech therapy (MLT) in reconstructive and orthopaedic surgery is widely described, post-operative complications related to leeches remain a major concern. Aeromonas spp. strains are involved in the majority of reported cases. As surgical success rate is directly impacted, an adapted antibiotic prophylaxis should be instituted in order to minimize these complications. We assessed pharmaceutical process, microbiological control and related infections in order to provide data and choose the appropriate antibiotherapy for patients requiring MLT. We report a clinical and microbiological study over a 24-month period. Clinical data were collected from patients' database, and microbiological analysis both on leeches' tank water and crushed leeches were performed to characterize isolated strains and their susceptibility to antibiotics. A total of 595 leeches were used to treat 28 patients (12 in plastic surgery and 16 in orthopaedic surgery), and three documented cases of post-operative infections were reported. Aeromonas spp. isolates yielded from 62 % of analyzed batches (75 % of Aeromonas veronii). Eighteen Aeromonas spp. isolates yielded from 23 water samples and three crushed leeches. Isolates were similar in tank and crushed leeches. Strains were susceptible to fluoroquinolones, sulfamethoxazole/trimethoprim, aminosides, and third-generation cephalosporins but resistant to amoxicillin/clavulanic acid and second-generation cephalosporins. According to collected data, routine tank water microbiological analyses are mandatory in order to identify leeches' batches containing resistant strains and to discard them. In this context, the surgeon is able to select an appropriated antibiotic prophylaxis in order to avoid MLT associated serious post-operative complications. PMID:27039338

  7. SPP retains interest in geothermal project

    International Nuclear Information System (INIS)

    Slovensky plynarensky priemysel (SPP) officially indicated that it intended to drop its project of using geothermal energy in the Kosicka kotlina. This spring it published an advert that it was looking for a company that wished to acquire a majority stake in the company, Geoterm Kosice. The company was established to commercially develop this geothermal source. But it seems SPP does not want to drop the project completely. It has kept some important cards, such as control over the land where the boreholes are located. Any company that wants to use geothermal energy needs a ruling issued by the Ministry of Environment defining the exploration area. Geothermal sources were found in the villages of Durkov, Svinica, Bidovce and Olsovany. Not so long ago the area was assigned to Geoterm but from May 9 2008 the area can be explored by Slovgeoterm. Both companies have the same majority shareholder - SPP. It controls 96% of Geoterm shares and 50% of Slovgeoterm. So far it has only officially announced its intention to sell the Geoterm shares. But as far as the use of the geothermal resource is concerned since May Slovgeoterm has played a key role.The company focuses on the utilization of geothermal energy. In addition to the project in the Kosice region, it has also participated in a project to heat more than a thousand flats using geothermal water in Galanta and a project to heat greenhouses in Podhajske. There are also other geothermal projects running in Presov and Michalovce. Icelandic company, Enex, with the same specialisation controls 28% of the company and a further 20% is owned by the investment group, NEFCO based in Helsinki. Two percent of the company is owned by its general director and the general proxy of Geoterm, Otto Halas. And so without the agreement of this company no-one can start any activities related to the utilization of geothermal energy. (authors)

  8. SPP retains interest in geothermal project

    International Nuclear Information System (INIS)

    Slovensky plynarensky priemysel (SPP) officially indicated that it intended to drop its project of using geothermal energy in the Kosicka kotlina. This spring it published an advert that it was looking for a company that wished to acquire a majority stake in the company, Geoterm Kosice. The company was established to commercially develop this geothermal source. But it seems SPP does not want to drop the project completely. It has kept some important cards, such as control over the land where the boreholes are located Any company that wants to use geothermal energy needs a ruling issued by the Ministry of Environment defining the exploration area. Geothermal sources were found in the villages of Durkov, Svinica, Bidovce and Olsovany. Not so long ago the area was assigned to Geoterm but from May 9 the area can be explored by Slovgeoterm. Both companies have the same majority shareholder - SPP. It controls 96% of Geoterm shares and 50% of Slovgeoterm. So far it has only officially announced its intention to sell the Geoterm shares. But as far as the use of the geothermal resource is concerned since May Slovgeoterm has played a key role.The company focuses on the utilization of geothermal energy. In addition to the project in the Kosice region, it has also participated in a project to heat more than a thousand flats using geothermal water in Galanta and a project to heat greenhouses in Podhajske. There are also other geothermal projects running in Presov and Michalovce. Icelandic company, Enex, with the same specialisation controls 28% of the company and a further 20% is owned by the investment group, NEFCO based in Helsinki. Two percent of the company is owned by its general director and the general proxy of Geoterm, Otto Halas. And so without the agreement of this company no-one can start any activities related to the utilization of geothermal energy. (authors)

  9. Extraction optimization of soluble compounds of yerba maté

    Directory of Open Access Journals (Sweden)

    César Sambiassi

    2002-06-01

    Full Text Available The objective of this research was the extraction optimization of water soluble compounds of yerba maté. Measures variables were extract concentration and weight of leaves and twigs. Controlled variables were time and temperature of extraction and water/solid relation. A surface response method of three variables was used as experimental design, with 20 experiences in each case. The range of each variable, defined in the experimental design, was: extraction time, 13.2 to 46.8 minutes; temperature, 48.2 to 81.8°C and water solid relation, 4.64 to 11.36 g water/100 g of dry solid. Extract weight varied from 13.14 to 29.56 g in leaves and 8.98 to 16.32 g in twigs (each one per 100 g of dry solid. Extract concentration varied between 2.17 and 3.43 g/100 ml in leaves and between 1.32 and 2.31 g/100 ml in twigs. The results were fit to a linear equation in each case.O objetivo desta pesquisa foi a otimização da extração aquosa da erva mate. As variáveis medidas foram a concentração do extrato e a massa das folhas e ramos. As variáveis controladas foram: o tempo e a temperatura de extração e a relação água/sólido. Como desenho experimental foi utilizado o método de resposta superficial de três variáveis, com vinte experiências em cada caso. A faixa de variação definida para as variáveis no desenho experimental foram: tempo de extração, de 13,2 a 46,8 minutos; temperatura, de 48,2 a 81,8 °C; relação água/sólido, de 4,64 a 11,36 gramas de água por gramas de sólido seco. A massa do extrato variou de 13,14 a 29,56 gramas para as folhas desramificadas e de 8,98 a 16,32 para os ramos (cada por 100 gramas de sólido seco. A concentração de extrato variou entre 2,17 a 3,43 g/ 100 ml nas folhas e entre 1,32 e 2,31 g/ 100 ml nos ramos. Os resultados foram, em ambos casos, ajustados para uma equação linear.

  10. Rooting cuttings of yam (Dioscorea spp.)

    OpenAIRE

    Luiz Eduardo Rocha e Silva; Roseane Cristina Prédes Trindade; Eurico Eduardo Pinto Lemos

    2014-01-01

    The culture of yams (Dioscorea spp.) has great importance for the entire Brazilian population, mainly in the Northeast, either by its nutritional or commercial value. This work aimed to study a new method of seedling production of yams by stem cuttings collected from plants with age of 120 days. The experiment was carried out in the CECA/UFAL, in a green house with intermittent fogging, in a fully randomized block design with a factorial 3 × 2 × 2, 12 treatments and 4 replications. Three f...

  11. Anther culture of chili pepper (Capsicum spp.).

    Science.gov (United States)

    Ochoa-Alejo, Neftalí

    2012-01-01

    Chili pepper (Capsicum spp.) is a very important horticultural crop around the world and is especially important for Mexicans because of its impact in the culture and the cuisine. Biotechnological tools such as tissue culture techniques and specifically anther culture may be applied successfully for plant breeding and genetic improvement in order to generate isogenic lines (100% homozygous) in a shorter time in comparison with the classic breeding methods. In this chapter, a protocol for efficient recovery of chili pepper haploid plants from in vitro cultured anthers is described. PMID:22610631

  12. Growth of Pseudomonas spp. in cottage cheese

    DEFF Research Database (Denmark)

    Østergaard, Nina Bjerre; Dalgaard, Paw

    spoilage microorganisms in cottage cheese can cause undesirable alterations in flavour, odour, appearance and texture. Contamination and growth of psychrotolerant pseudomonads including Pseudomonas fragi and Pseudomonas putida has been reported for cottage cheese but the influence of these bacteria on...... (pH 7.0) showed interesting results. Despite a lower pH value in the cottage cheese, compared to the dressing, more rapid growth was observed. This may be caused by insufficient amounts of oxygen in the cream dressing having a negative effect on growth of Pseudomonas spp. At 15˚C growth of...

  13. First report of Colletotrichum spp. causing diseases on Capsicum spp. in Sabah, Borneo, Malaysia

    Directory of Open Access Journals (Sweden)

    H.K. Yun

    2009-08-01

    Full Text Available Blackish or orange liquid-like spots were found on (n=100 fruits of chillies (Capsicum sold in five local markets in Kota Kinabalu, Sabah, Malaysia. Colletotrichum gloeosporioides and C. capsici were identified as the causal agents of an anthracnose disease. This is the first report of Colletotrichum spp. as the causal agent of anthracnose infected chillies in Sabah.

  14. Deposition of Biogenic Iron Minerals in a Methane Oxidizing Microbial Mat

    Directory of Open Access Journals (Sweden)

    Christoph Wrede

    2013-01-01

    Full Text Available The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  15. Matériaux organiques pour le génie civil : Approche physico-chimique

    OpenAIRE

    Mouton, Y

    2003-01-01

    Les matériaux organiques sont omniprésents dans le génie civil : bitume sur la route, géotextiles pour les murs de soutènement, membranes pour l'étanchéité des ponts, des tunnels ou des réservoirs, liants de peinture pour la protection des ouvrages métalliques ou du béton, ou encore pour le marquage routier, résines d'injection, produits de collage, adjuvants du béton, matériaux composites, etc. Leur caractère commun réside dans leur structure qui est du ressort de la chimie organique. Matéri...

  16. Superhydrophobic PVDF and PVDF-HFP nanofibrous mats with antibacterial and anti-biofouling properties

    Science.gov (United States)

    Spasova, M.; Manolova, N.; Markova, N.; Rashkov, I.

    2016-02-01

    Superhydrophobic nanofibrous materials of poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were prepared by one-pot electrospinning technique. The mats were decorated with ZnO nanoparticles with silanized surface and a model drug - 5-chloro-8-hydroxyquinolinol (5Cl8HQ). The obtained hybrid nanofibrous materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle measurements, mechanical and microbiological tests. The results showed that the incorporation of ZnO nanoparticles into PVDF and PVDF-HFP nanofibers increased the hydrophobicity (contact angle 152°), improved the thermal stability and imparted to the nanofibrous materials anti-adhesive and antimicrobial properties. The mats containing the model drug possessed antibacterial activity against Escherichia coli and Staphylococcus aureus. The results suggested that the obtained hybrid mats could find potential biomedical applications requiring antibacterial and anti-biofouling properties.

  17. A Matérn model of the spatial covariance structure of point rain rates

    KAUST Repository

    Sun, Ying

    2014-07-15

    It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.

  18. Effect of irradiation on physiological and biochemical property of mat rush seedlings

    International Nuclear Information System (INIS)

    The seeds of different varieties of mat rush were treated by 60Co γ-rays irradiation of 500, 1000, 1500 and 2000 Gy. The seedlings cultured from treated seeds ere used to detect the root activity, seedling growth, chlorophyll content, activities of polyphenol oxidase and catalase, and to investigate the effect of irradiation treatment on the physiological and biochemical properties of mat rush. The results showed that root activity, chlorophyll content and polyphenol oxidase activity of the control group was higher than those of all treatment groups, indicating that irradiation treatment could affect the above physiological and biochemical traits. Meanwhile, it was found that hydrogen peroxide activity of 500 Gy treatment was higher than that of CK and other treatment. In addition, with dose increasing, the stem length of seedlings was increased, suggesting that irradiation treatment could promote the seedling growth within some range of dosage. 500 Gy was recommended as suitable dosage for irradiation mutagenesis of mat rush. (authors)

  19. Spatial patterns and links between microbial community composition and function in cyanobacterial mats

    Directory of Open Access Journals (Sweden)

    MohammadA. A.Al-Najjar

    2014-08-01

    Full Text Available We imaged reflectance and variable fluorescence in 25 cyanobacterial mats from 4 distant sites around the globe to assess, at different scales of resolution, spatial variabilities in the physiological parameters characterizing their photosynthetic capacity, including the absorptivity by chlorophyll a (A_chl, maximum quantum yield of photosynthesis (Y_max and light acclimation irradiance (I_k. Generally, these parameters significantly varied within individual mats on a sub-millimeter scale, with about 2-fold higher variability in the vertical than in the horizontal direction. The average vertical profiles of Y_max and I_k decreased with depth in the mat, while A_chl exhibited a sub-surface maximum. The within-mat variability was comparable to, but often larger than, the between-sites variability, whereas the within-site variabilities (i.e., between samples from the same site were generally lowest. When compared based on averaged values of their photosynthetic parameters, mats clustered according to their site of origin. Similar clustering was found when the community composition of the mats' cyanobacterial layers were compared by automated ribosomal intergenic spacer analysis, indicating a significant link between the microbial community composition and function. Although this link is likely the result of community adaptation to the prevailing site-specific environmental conditions, our present data is insufficient to identify the main factors determining these patterns. Nevertheless, this study demonstrates that the spatial variability in the photosynthetic capacity and light acclimation of benthic phototrophic microbial communities is at least as large on a sub-millimeter scale as it is on a global scale, and suggests that this pattern of variability scaling is similar for the microbial community composition.

  20. Energy saving by improving the insulation of mat foundation slab. Energiansaeaestoemahdollisuudet maanvaraisen alapohjarakenteen laemmoeneristettae parantamalla

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, J.; Viljanen, M. (Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Structural Engineering and Building Physics); Friberg, P.; Slunga, E. (Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Soil Mechanics); Lehtinen, T. (Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Structural Engineering)

    1992-01-01

    In the research the energy saving possibilities of mat foundation slabs were studied in the structural engineering point of view. The energy saving levels were 25 %, 50 % and 75 % compared to the structures in use nowadays. The energy consumptions of the mat foundation slabs, whose thermal insulation were improved, were calculated by numerical two dimensional program. The ability of use a trace gas method to detect uncontrolled air flows was studied by laboratory tests. The effect of the underground air flows on the thermal behavior of mat slabs studied by field measurements and laboratory tests. The frost insulations of mat slabs will be designed individually. In the structural designing the frost insulations calculated in the research can be used for help as far as they are applicable to the case. Instead of the individual designing frost insulations can be determined by using the regulations of unheated houses or the foundation level can be lowered. The laboratory and field tests show, that the airtightness of foundation structures in use, especially the plinth, should be taken more carefully into account to get as good as possible correlations between the calculated and the real energy consumption. The trace gas method can be used to detect uncontrolled air flows in the slab insulation. The use of the saxon pipe system as a radon technical solution in energy saving mat slabs structures should be researched before taken in use. The moisture technical designing of energy saving mat slabs should be done by numerical calculations. Wood base materials can't be used without special examination below the upper surface of the slab thermal insulation

  1. Spatial patterns and links between microbial community composition and function in cyanobacterial mats

    KAUST Repository

    Al-Najjar, Mohammad A. A.

    2014-08-06

    We imaged reflectance and variable fluorescence in 25 cyanobacterial mats from four distant sites around the globe to assess, at different scales of resolution, spatial variabilities in the physiological parameters characterizing their photosynthetic capacity, including the absorptivity by chlorophyll a (Achl), maximum quantum yield of photosynthesis (Ymax), and light acclimation irradiance (Ik). Generally, these parameters significantly varied within individual mats on a sub-millimeter scale, with about 2-fold higher variability in the vertical than in the horizontal direction. The average vertical profiles of Ymax and Ik decreased with depth in the mat, while Achl exhibited a sub-surface maximum. The within-mat variability was comparable to, but often larger than, the between-sites variability, whereas the within-site variabilities (i.e., between samples from the same site) were generally lowest. When compared based on averaged values of their photosynthetic parameters, mats clustered according to their site of origin. Similar clustering was found when the community composition of the mats\\' cyanobacterial layers were compared by automated ribosomal intergenic spacer analysis (ARISA), indicating a significant link between the microbial community composition and function. Although this link is likely the result of community adaptation to the prevailing site-specific environmental conditions, our present data is insufficient to identify the main factors determining these patterns. Nevertheless, this study demonstrates that the spatial variability in the photosynthetic capacity and light acclimation of benthic phototrophic microbial communities is at least as large on a sub-millimeter scale as it is on a global scale, and suggests that this pattern of variability scaling is similar for the microbial community composition. © 2014 Al-Najjar, Ramette, Kühl, Hamza, Klatt and Polerecky.

  2. Pertumbuhan Optimum Penicillium spp. dan Cunninghamella spp. yang Diisolasi dari Pakan dan Efek Toksiknya pada Mencit (Mus musculus)

    OpenAIRE

    Ramli, N; M. Tafsin; A.D Hasjmy

    2009-01-01

    Fungi are a major microorganism present in the feedstuffs that able to reduce nutritive value and produce toxin that harmful for animal. Penicillium spp. and Cunninghamella spp. were dominant present in the feedstuffs in tropical regions. The objectives of this study were to find out the optimum pH and temperature of Penicillium spp. and Cunninghamella spp. on agar media and to find out the effect of feeding diet containing corn contaminated with the fungi at level of 0%, 50% and 100% on the ...

  3. Different sensing mechanisms in single wire and mat carbon nanotubes chemical sensors

    CERN Document Server

    Neumann, P L; Dobrik, G; Kertész, K; Horváth, E; Lukács, I E; Biró, L P; Horváth, Z E

    2014-01-01

    Chemical sensing properties of single wire and mat form sensor structures fabricated from the same carbon nanotube (CNT) materials have been compared. Sensing properties of CNT sensors were evaluated upon electrical response in the presence of five vapours as acetone, acetic acid, ethanol, toluene, and water. Diverse behaviour of single wire CNT sensors was found, while the mat structures showed similar response for all the applied vapours. This indicates that the sensing mechanism of random CNT networks cannot be interpreted as a simple summation of the constituting individual CNT effects, but is associated to another robust phenomenon, localized presumably at CNT-CNT junctions, must be supposed.

  4. UV B-Induced Vertical Migrations of Cyanobacteria in a Microbial Mat

    OpenAIRE

    Bebout, B. M.; Garcia-Pichel, F

    1995-01-01

    Exposure to moderate doses of UV B (0.35 to 0.79 W m(sup-2) s(sup-1) or 0.98 to 2.2 (mu)mol of photons m(sup-2) s(sup-1) at 310 nm) caused the surface layers of microbial mats from Solar Lake, Sinai, Egypt, to become visibly lighter green. Concurrent with the color change were rapid and dramatic reductions in gross photosynthesis and in the resultant high porewater oxygen concentrations in the surface layers of the mats. The depths at which both maximum gross photosynthesis and maximum oxygen...

  5. Description of the HiMAT Tailored composite structure and laboratory measured vehicle shape under load

    Science.gov (United States)

    Monaghan, R. C.

    1981-01-01

    The aeroelastically tailored outer wing and canard of the highly maneuverable aircraft technology (HiMAT) vehicle are closely examined and a general description of the overall structure of the vehicle is provided. Test data in the form of laboratory measured twist under load and predicted twist from the HiMAT NASTRAN structural design program are compared. The results of this comparison indicate that the measured twist is generally less than the NASTRAN predicted twist. These discrepancies in twist predictions are attributed, at least in part, to the inability of current analytical composite materials programs to provide sufficiently accurate properties of matrix dominated laminates for input into structural programs such as NASTRAN.

  6. NanoSIP: Developing Community Imaging for Phylogenetic and Functional Characterization Using Cyanobacterial Mats

    Energy Technology Data Exchange (ETDEWEB)

    Woebken, D., L.C. Burow, L. Prufert-Bebout, B.M. Bebout, T. M. Hoehler, J. Pett-Ridge, A.M. Spormann; Singer, S W; McMurdie, P J; Weber, P K

    2011-10-01

    This project was to develop and optimize the following technologies: stable isotope probing + NanoSIMS analysis (nanoSIP), FISH, functional gene analysis, H2 production measurements, culturing, and metatranscriptomics for specific use in microbial mat systems. The larger goal was to further develop these methodologies in a way that facilitates their linkage, high fidelity 3-D correlation to location specific environmental change integrating geochemical characterization, such that ability to see and characterize microbial community responses to normal daily fluctuations and further ecological manipulations, in different locations of the mat communities is optimized.

  7. The parametric study of SSI analysis for large mat foundation structure

    International Nuclear Information System (INIS)

    The developments of in-structure response spectrum (IRS) are major procedures of Generic Implementation Procedure (GIP) for the resolution of USI A-46. There are many factors influencing to IRS characteristics; especially the characteristics of surrounding soil of foundation affect the frequency and amplification IRS peaks. The most of soil-structure interaction (SSI) analyses for a large mat foundation such as base of the auxiliary building complex have been performed by simplified approaches, because of its complexity and huge computing cost. In this paper, the parametric study of SSI analysis about large mat foundation was performed. As a tool of SSI analyses, the program SASSI was used

  8. MAT-DB - A database for nuclear energy related materials data

    International Nuclear Information System (INIS)

    The web-enabled materials database (Mat-DB) of JRC-IE has a long-term history in storing materials test data resulting from European and international research projects. The database structure and the user-guidance has bee permanently updated improved and optimized. The database is implemented in the secure ODIN portal: https://odin.jrc.ec.europa.eu of JRC-IE. This architecture guarantees fast access to confidential and public data and documentation which are stored in an inter-related document management database (DoMa). It is a part of JRC's nuclear knowledge management. Mat-DB hosts the whole pool of IAEA surveillance data of reactor pressure vessel materials from different nuclear power plants of the member states. Mat-DB contains also thousands of European GEN IV reactor systems related R and D materials data which are an important basis for the evaluating and extrapolating design data for candidate materials and setting up design rules covering high temperature exposure, irradiation and corrosion. Those data and rules would match also fusion related components. Mat-DB covers thermo-mechanical and thermo-physical properties data of engineering alloys at low, elevated and high temperatures for base materials and joints, including irradiated materials for nuclear fission and fusion applications, thermal barrier coated materials for gas turbines and properties of corroded materials. The corrosion part refers to weight gain/loss data of high temperature exposed engineering alloys and ceramic materials. For each test type the database structure reflects international test standards and recommendations. Mat-DB features an extensive library of evaluation programs for web-enabled assessment of uniaxial creep, fatigue, crack growth and high temperature corrosion properties. Evaluations can be performed after data retrieval or independently of Mat-DB by transferring other materials data in a given format to the programs. The fast evaluation processes help the user to

  9. Photosynthetic Potential and Light-Dependent Oxygen Consumption in a Benthic Cyanobacterial Mat

    OpenAIRE

    Jørgensen, Bo Barker; Cohen, Yehuda; Revsbech, Niels Peter

    1988-01-01

    The potential to carry out oxygenic photosynthesis after prolonged burial below the photic zone was studied at 0.1-mm depth intervals in the thick, laminated Microcoleus chthonoplastes mats growing in Solar Lake, Sinai. The buried mat community lost about 20% of its photosynthetic potential with depth per annual layer down to 8- to 10-year-old layers at a 14-mm depth. In some of the older layers, below a 30-mm depth, light-dependent oxygen consumption which increased with increasing light int...

  10. The effectiveness of the 4MAT teaching model upon student achievement and attitude levels

    OpenAIRE

    UYANGÖR, Sevinç MERT

    2012-01-01

    4MAT is an 8-step, sequential instructional model based on two theoretical constructs: Kolb's model of learning styles and the concept of brain hemisphericity. The model, developed by B. McCarthy (1987) is derived by interacting each of Kolb's four quadrants with both left and right brain. The purpose of this study is to examine the influence of the 4MAT teaching model which depends on learning styles that have been generated by the help of the relationship between the brain and learning; and...

  11. Modular development mat reinforcing and liners containment/annulus building. Final report supplement. Volume I

    International Nuclear Information System (INIS)

    The feasibility of developing a modular system approach for the construction of containment mats has been established. The investigative results obtained from a plant used for the modular study has determined that (1) modularization results in a 10-week reduction in the construction schedule critical path over that for the conventional approach, and (2) modularization is cost effective and could result in a savings of approximately $10,700,000. Accordingly, it is recommended that the modular system approach be adopted as standard practice for the construction of containment mats

  12. Aeromonas spp.: An Emerging Nosocomial Pathogen.

    Science.gov (United States)

    Batra, Priyam; Mathur, Purva; Misra, Mahesh C

    2016-01-01

    Aeromonads are hallophillic, nonacid fast, nonspore forming, Gram-negative rods which are widely distributed in the soil, foodstuffs, and aquatic environment. Since times immemorial, they are important zoonotic pathogens of poikilotherms but are now emerging as important human pathogens. These emerging enteric pathogens flourish in the water distribution system by forming biofilms. They possess large number of virulence factors including inherent resistance to various antibiotics and ability to form biofilms using quorum sensing. These properties make them easy pathogens for human infections. Aeromonads are important enteric pathogens, but, with the growing level of immunosuppression in the population, they have been associated with various extraintestinal infections, such as skin and soft-tissue infections, traumatic wound infections, and lower respiratory tract/urinary tract infections. The average annual incidence of bacteremia in Southern Taiwan due to Aeromonas spp. was 76 cases/million inhabitants between 2008 and 2010. However, the incidence reported from Western countries is much lower. The case fatality rate among patients with Aeromonas bacteremia ranges from 27.5 to 46%. Aeromonads are universally resistant to the narrow-spectrum penicillin group of antibiotics such as penicillin, ampicillin, carbenicillin, and ticarcillin. They are however susceptible to piperacillin, azlocillin, second and third generation cephalosporins, and carbapenems. Most of the Aeromonas species are susceptible to aminoglycosides, tetracycline, chloramphenicol, trimethoprim-sulfamethoxazole, quinolones, and monobactams. This manuscript is a comprehensive systematic review of the literature available on Aeromonas spp. PMID:27013806

  13. Aeromonas spp.: An emerging nosocomial pathogen

    Directory of Open Access Journals (Sweden)

    Priyam Batra

    2016-01-01

    Full Text Available Aeromonads are hallophillic, nonacid fast, nonspore forming, Gram-negative rods which are widely distributed in the soil, foodstuffs, and aquatic environment. Since times immemorial, they are important zoonotic pathogens of poikilotherms but are now emerging as important human pathogens. These emerging enteric pathogens flourish in the water distribution system by forming biofilms. They possess large number of virulence factors including inherent resistance to various antibiotics and ability to form biofilms using quorum sensing. These properties make them easy pathogens for human infections. Aeromonads are important enteric pathogens, but, with the growing level of immunosuppression in the population, they have been associated with various extraintestinal infections, such as skin and soft-tissue infections, traumatic wound infections, and lower respiratory tract/urinary tract infections. The average annual incidence of bacteremia in Southern Taiwan due to Aeromonas spp. was 76 cases/million inhabitants between 2008 and 2010. However, the incidence reported from Western countries is much lower. The case fatality rate among patients with Aeromonas bacteremia ranges from 27.5 to 46%. Aeromonads are universally resistant to the narrow-spectrum penicillin group of antibiotics such as penicillin, ampicillin, carbenicillin, and ticarcillin. They are however susceptible to piperacillin, azlocillin, second and third generation cephalosporins, and carbapenems. Most of the Aeromonas species are susceptible to aminoglycosides, tetracycline, chloramphenicol, trimethoprim-sulfamethoxazole, quinolones, and monobactams. This manuscript is a comprehensive systematic review of the literature available on Aeromonas spp.

  14. The application of matK sequence as DNA barcode in Xanthium%matK序列作为DNA条形码在苍耳属中的应用

    Institute of Scientific and Technical Information of China (English)

    胡伟毅; 邵套喜

    2013-01-01

    matK序列作为DNA条形码,对从国外截获的7种苍耳属植物进行物种区分鉴定研究,采用DNeasy(R)Plant Mini Kit试剂盒进行总DNA的提取,应用通用引物对其matK基因进行扩增,测序得到7种苍耳属植物的matK序列,利用MEGA 5.1软件对这7种苍耳属植物的matK序列进行比对和分析并构建系统树,结果显示:matK序列能从基因位点层面对苍耳属植物进行区分鉴定.

  15. Manejo da adubação nitrogenada de tensões hídricas sobre a produção de matéria seca e índice de área foliar de Tifton 85 cultivado no Cerrado Management of nitrogen fertilization and of water tension on the production of dry matter and leaf area index of Tifton 85 cultivated in the Cerrado region

    OpenAIRE

    Kênia Régia Anasenko Marcelino; Lourival Vilela; Gilberto Gonçalves Leite; Antônio Fernando Guerra; José Mauro da Silva Diogo

    2003-01-01

    Este trabalho foi conduzido na Embrapa Cerrados, Planaltina (DF), objetivando avaliar a influência de tensões hídricas (35, 60, 100 e 500 kPa) e doses de nitrogênio (0 - Testemunha, 45, 90, 180, 360 kg/ha) sobre a produção de matéria seca (MS), a taxa de produção de matéria seca (TPMS) e o índice de área foliar (IAF) do capim Cynodon spp. cv. Tifton 85. Empregou-se delineamento em blocos ao acaso, com parcelas subdivididas em três repetições; nas parcelas foram distribuídas as tensões e nas s...

  16. Characterization and Modification of Electrospun Fiber Mats for Use in Composite Proton Exchange Membranes

    Science.gov (United States)

    Mannarino, Matthew Marchand

    Electrostatic fiber formation, or electrospinning, offers a particularly simple and robust method to create polymeric nanofibers of various sizes and morphologies. In electrospinning, a viscoelastic fluid is charged so that a liquid jet is ejected from the surface of the fluid (typically in the form of a drop supplied by a needle or spinneret) and collected on a grounded plate, creating a nonwoven fiber mat. Modification of the diameter of the fibers as well as the porosity, specific surface area, and mechanical properties of the mat allows one to tailor electrospun mats for specific applications. Despite the widespread and rapidly growing use of electrospinning in the fabrication of novel nanomaterials, there are no simple, universal methods of predicting, a priori, the properties of electrospun fibers from knowledge of the polymer solution properties and electrospinning operating conditions alone. Changing a single fluid or processing parameter can affect the jet and fiber formation through several mechanisms. For example, using a different solvent can change several properties of the electrospinning fluid, such as the dielectric constant, conductivity, surface tension, and solute-solvent interaction. The work in this thesis seeks to develop a simple relation for predicting terminal jet diameter during electrospinning, which accounts for solution viscoelasticity as well as solution conductivity and operating parameters that can be easily measured and controlled. The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility as components in a variety of applications. Although some mechanical properties of these mats have been investigated previously, reports of their tribological properties are essentially nonexistent. In this thesis, electrospun nanofiber mats of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) and poly(hexamethylene adipamide) (PA 6,6) are characterized mechanically and tribologically

  17. A new selective medium for isolating Pseudomonas spp. from water.

    OpenAIRE

    Krueger, C L; Sheikh, W

    1987-01-01

    A new medium, pseudomonas selective isolation agar, was developed to isolate Pseudomonas spp. from water. It consists of 350 micrograms of nitrofurantoin per ml and 2 micrograms of crystal violet per ml in a nutrient agar base. It is more selective for Pseudomonas spp. than are available commercial media. Its ingredients are inexpensive and readily available, and it is easy to prepare.

  18. 21 CFR 866.3085 - Brucella spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Brucella spp. serological reagents. 866.3085 Section 866.3085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3085 Brucella spp. serological reagents. (a)...

  19. Evaluation of transport methods for isolating Shigella spp.

    OpenAIRE

    Wells, J G; Morris, G K

    1981-01-01

    Recovery of Shigella spp. from fecal specimens transported in buffered glycerol saline and Cary-Blair media held at frozen, refrigerated, or room temperature was compared with recovery by direct plating of fecal specimens. Buffered glycerol saline was the better transport medium for the recovery of Shigella spp. Refrigerated or frozen transport temperatures were superior to room temperature for recovery from either medium.

  20. Severe Candida spp. infections: new insights into natural immunity.

    NARCIS (Netherlands)

    Meer, J.W.M. van der; Veerdonk, F.L. van de; Joosten, L.A.B.; Kullberg, B.J.; Netea, M.G.

    2010-01-01

    Invasive infections caused by Candida spp. are associated with high mortality. Colonisation by Candida spp. and the capacity of the host to recognise them as potential pathogens are essential steps in the development of these infections. The major pathogen-associated molecular patterns of Candida ar

  1. The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface Hydrothermal Circulation

    OpenAIRE

    Teske, Andreas; de Beer, Dirk; McKay, Luke J.; Margaret K. Tivey; Biddle, Jennifer F.; Hoer, Daniel; Lloyd, Karen G.; Lever, Mark A.; Røy, Hans; Albert, Daniel B.; Mendlovitz, Howard P.; MacGregor, Barbara J.

    2016-01-01

    The hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediment...

  2. Effects of base mat flexibility and structure-soil-structure interaction on the seismic responses of a nuclear stack building

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, A.F.; Malik, L.E. [Advanced Engineering Consultants, Inc., San Francisco, CA (United States); Maryak, M.E. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1991-12-31

    A nuclear exhaust stack building was analyzed considering flexibility of the base mat and through-soil coupling with a nearby massive reactor building. The analysis indicated that the base mat flexibility and the proximity of the reactor building significantly affect the seismic responses of the stack building.

  3. Effects of base mat flexibility and structure-soil-structure interaction on the seismic responses of a nuclear stack building

    International Nuclear Information System (INIS)

    A nuclear exhaust stack building was analyzed considering flexibility of the base mat and through-soil coupling with a nearby massive reactor building. The analysis indicated that the base mat flexibility and the proximity of the reactor building significantly affect the seismic responses of the stack building. (author)

  4. Effects of base mat flexibility and structure-soil-structure interaction on the seismic responses of a nuclear stack building

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, A.F.; Malik, L.E. (Advanced Engineering Consultants, Inc., San Francisco, CA (United States)); Maryak, M.E. (Westinghouse Savannah River Co., Aiken, SC (United States))

    1991-01-01

    A nuclear exhaust stack building was analyzed considering flexibility of the base mat and through-soil coupling with a nearby massive reactor building. The analysis indicated that the base mat flexibility and the proximity of the reactor building significantly affect the seismic responses of the stack building.

  5. Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning– electrospraying hybrid process for use in protective applications

    Science.gov (United States)

    ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacter...

  6. Giardia spp. e Cryptosporidium spp. em água de manancial superficial de abastecimento contaminada por dejetos humano e animal Giardia spp. and Cryptosporidium spp. in a fresh water supply source contaminated with human and animal excreta and waste water

    Directory of Open Access Journals (Sweden)

    G.M.F. Dias

    2008-12-01

    Full Text Available Estudou-se ocorrência de cistos de Giardia spp. e oocistos de Cryptosporidium spp. - (oocistos - na bacia hidrográfica do Ribeirão São Bartolomeu, localizada no município de Viçosa, MG. O estudo incluiu as populações humana e animal existentes na área da bacia, bem como no efluente de uma estação de tratamento de esgoto (ETE e de duas instalações para suínos. Os resultados indicam presença de (oocistos no manancial (médias geométricas: 3,92 e 3,62 (oocistos/l para Giardia spp. e Cryptosporidium spp., respectivamente. Propriedades com exploração bovina foram positivas ao longo de todo período (prevalência média de propriedades positivas 36,4% para Giardia spp. e 18,0% para Cryptosporidium spp.. O efluente da ETE apresentou elevada concentração de cistos de Giardia spp. (média geométrica na ordem de 10(4/l, mas não foram encontrados oocistos de Cryptosporidium spp. A ocorrência de (oocistos apresentou comportamento sazonal, sendo que os valores médios de (oocistos e de pluviosidade do trimestre de coleta revelaram bom ajuste de correlação (R²=98,3%; P=0,0087 para Giardia spp. e R²=91,8%; P=0,0421 para Cryptosporidium spp.. A significativa ocorrência de (oocistos no manancial sugere que a forma de ocupação do solo interfere na qualidade parasitológica da água bruta. Os resultados apontam para a importância de adoção de medidas preventivas, como proteção de áreas de mananciais, objetivando reduzir riscos de transmissão de protozoários via água de consumo humano.The occurrence of Giardia spp. cysts and Cryptosporidium spp. oocysts - (oocysts - was studied in a watershed (São Bartolomeu Stream-SB, at Viçosa city, MG. In the studied area, characterization of animal farms and identification of sewage and animal wastes discharges were undertaken. In addition, a sewage treatment plant (STP and effluents of two swine farms were sampled. The results presented protozoan contamination (geometric averages: 3

  7. Preparation and photochromic properties of ultra-fine H3PW11MoO40/PVA fibre mats

    International Nuclear Information System (INIS)

    Novel photochromic materials, H3PW11MoO40/Poly (vinyl alcohol) (PVA) ultra-fine fibre mats containing different weight percentages of H3PW11MoO40, have been prepared from different H3PW11MoO40/PVA solutions by an electrospinning technique. IR spectroscopy, wide-angle x-ray diffraction, and scanning electron microscope spectroscopy are used to characterize the fibre mats. Results of viscosity and conductivity measurements of the solutions indicate that lower viscosity and higher conductivity favour the formation of thin fibres without beads. When irradiated with ultraviolet light (313.2 nm), the colour of the fibre mats changes from white to blue, and the mats show reversible photochromism. IR and ESR spectra of the irradiated fibre mats indicate a conceivable photochromic mechanism, i.e. MoVI is reduced under ultraviolet irradiation. Meanwhile, PVA is oxidized to unsaturated ketone or aldehyde

  8. Modulation of a fluorescence switch of nanofiber mats containing photochromic spironaphthoxazine and D-π-A charge transfer dye

    International Nuclear Information System (INIS)

    Photoswitchable poly(methyl methacrylate) (PMMA) nanofiber mats containing spironaphthoxazine (SPO)/electron donor-π-acceptor (D-π-A) type fluorescent dye (TCF) were prepared by electrospinning. The photoregulated fluorescence switching behaviors of SPO/TCF blended solution and PMMA nanofiber mats containing SPO/TCF were also studied. Not only SPO/TCF blended solution but also PMMA nanofiber mats containing SPO/TCF showed reversible modulation of fluorescence intensity using alternating irradiation with UV and visible light. Highlights: ▶ We have designed PMMA nanofiber mats containing a photochromic SPO and fluorescent TCF. ▶ Photoswitchable PMMA nanofiber mats containing SPO/TCF were prepared by electrospinning. ▶ Reversible modulation of fluorescence intensity was achieved by irradiation with UV/vis.

  9. Characterization of geographically distinct bacterial communities associated with coral mucus produced by Acropora spp. and Porites spp.

    Science.gov (United States)

    McKew, B A; Dumbrell, A J; Daud, S D; Hepburn, L; Thorpe, E; Mogensen, L; Whitby, C

    2012-08-01

    Acropora and Porites corals are important reef builders in the Indo-Pacific and Caribbean. Bacteria associated with mucus produced by Porites spp. and Acropora spp. from Caribbean (Punta Maroma, Mexico) and Indo-Pacific (Hoga and Sampela, Indonesia) reefs were determined. Analysis of pyrosequencing libraries showed that bacterial communities from Caribbean corals were significantly more diverse (H', 3.18 to 4.25) than their Indonesian counterparts (H', 2.54 to 3.25). Dominant taxa were Gammaproteobacteria, Alphaproteobacteria, Firmicutes, and Cyanobacteria, which varied in relative abundance between coral genera and region. Distinct coral host-specific communities were also found; for example, Clostridiales were dominant on Acropora spp. (at Hoga and the Mexican Caribbean) compared to Porites spp. and seawater. Within the Gammproteobacteria, Halomonas spp. dominated sequence libraries from Porites spp. (49%) and Acropora spp. (5.6%) from the Mexican Caribbean, compared to the corresponding Indonesian coral libraries (coral mucus. In addition, the predominance of Clostridiales associated with Acropora spp. provided additional evidence for coral host-specific microorganisms. PMID:22636010

  10. Contamination of public parks and squares from Guarulhos (São Paulo State, Brazil by Toxocara spp. and Ancylostoma spp.

    Directory of Open Access Journals (Sweden)

    Jacó Pereira Marques

    2012-10-01

    Full Text Available The contaminated soil with mammal feces is an important factor of risk to infection with zoonotic diseases. Amongst these zoonoses are visceral larva migrans and cutaneous larva migrans caused by Toxocara spp. and Ancylostoma spp., respectively. The aim of this study was to assess the environmental contamination by Toxocara spp. eggs and hookworms (Ancylostoma spp. in public parks and squares in the city of Guarulhos, a metropolitan area of São Paulo, São Paulo State, Brazil. Soil samples were collected, between September and December 2010, and examined using the centrifugal flotation technique with sodium dichromate and zinc sulphate as well as the modified Baermann method. Notably, 35 (74.5% of the 47 districts surveyed in Guarulhos possessed samples contaminated with Toxocara spp. and/or eggs or larvae of Ancylostoma spp. The frequency of Toxocara spp. and Ancylostoma spp. in the samples from public areas was 68.1% and 46.8%, respectively. Overall, the eastern side of Guarulhos is the region with the highest occurrence of causative agents of larva migrans. In all collection sites, the presence of feces from dogs and cats accompanied by their owners and stray animals were observed. Notably, it is important to adopt measures to control dog and cat breeding, to treat infected animals, and provide health education to the population.

  11. An Empirical Study of an RFID Mat Sensor System in a Group Home

    Directory of Open Access Journals (Sweden)

    Motoki Miura

    2009-04-01

    Full Text Available We have been developing an RFID (radio frequency identification mat system to assist caregivers in a group home. In Japan, the number of group homes offering home-like care for elderly persons suffering from dementia has increased considerably. Even though the smaller number of people residing in a group home makes it suitable for family-like care, the scarcity of caregivers increases the burden, especially during the night. To augment caregiver attention, we developed floor mats with embedded RFID antennae and slippers with RFID tags. These can help caregivers be aware of the activities of persons suffering from dementia by specifying whether an individual has passed over a mat in a particular corridor. This not only helps the caregivers understand such persons by reviewing their activities but also keeps them informed about their current activities. We introduced the floor mats in a real group home and confirmed the feasibility of the system. In this study, we describe the system and lessons learned from our experiment.

  12. Modeling the pullout characteristics of welded wire mats embedded in silty sand

    International Nuclear Information System (INIS)

    This paper is an outgrowth of the on-going research on discrete finite element modeling of welded wire mesh reinforced soil structures such as the welded wire and RSE walls. The stiffness characteristics of the wire mesh-soil interfaces are modeled by a nonlinear hyperbolic relationship between the applied pullout stress and the associated mat placement. The relevant parameters are estimated from laboratory pullout tests that were conducted for welded wire mats embedded on silty sand. Since the bulk of the pullout resistance of welded wire mesh reinforcements is derived from the bearing resistance of the transverse wires that constitute the test mats. This feature permits proper evaluation of actual interface parameters for the actual reinforced soil structures in which the actual lengths of the mats are longer (i.e. more transverse members) than the specimen used in the laboratory pullout tests. The resulting pullout stress-displacement formulations are then verified by comparing the predicted pullout resistance to the existing specifications and design methods for estimated the pullout capacities of grid reinforcements. 22 refs., 13 figs

  13. Effects of root mat buoyancy and heterogeneity on floating fen hydrology

    NARCIS (Netherlands)

    Stofberg, S.F.; Engelen, van Joeri; Witte, J.Ph.M.; Zee, van der S.E.A.T.M.

    2016-01-01

    Floating fen ecosystems are home to several protected habitats and species. Their development and conservation require special
    attention regarding water management. Although they are known to be heterogeneous and partially buoyant, their root mats are
    simulated in hydrological models as homo

  14. Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianqiang; Luo, Chao [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qi, Genggeng [Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Pan, Kai, E-mail: pankai@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Cao, Bing, E-mail: bcao@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

    2014-10-15

    Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr{sub 2}O{sub 7}{sup 2−} and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl{sup −} and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl{sup −}, NO{sub 3}{sup −}, and SO{sub 4}{sup 2−}) except for PO{sub 4}{sup 3−} for the pH change.

  15. Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr2O72− and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl− and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl−, NO3−, and SO42−) except for PO43− for the pH change

  16. Cooperação jurídica internacional em matéria civil

    OpenAIRE

    Carmen Tiburcio

    2013-01-01

    O trabalho cuida dos sistemas e dos instrumentos de cooperação em matéria civil no âmbito do Mercosul: Protocolos de Las Leñas e Ouro Preto. Analisam-se os textos dos respectivos tratados, a jurisprudência brasileira e de outros países do Mercosul.

  17. High diversity and widespread occurrence of mitotic spore mats in ectomycorrhizal Pezizales.

    Science.gov (United States)

    Healy, R A; Smith, M E; Bonito, G M; Pfister, D H; Ge, Z-W; Guevara, G G; Williams, G; Stafford, K; Kumar, L; Lee, T; Hobart, C; Trappe, J; Vilgalys, R; McLaughlin, D J

    2013-03-01

    Fungal mitospores may function as dispersal units and/ or spermatia and thus play a role in distribution and/or mating of species that produce them. Mitospore production in ectomycorrhizal (EcM) Pezizales is rarely reported, but here we document mitospore production by a high diversity of EcM Pezizales on three continents, in both hemispheres. We sequenced the internal transcribed spacer (ITS) and partial large subunit (LSU) nuclear rDNA from 292 spore mats (visible mitospore clumps) collected in Argentina, Chile, China, Mexico and the USA between 2009 and 2012. We collated spore mat ITS sequences with 105 fruit body and 47 EcM root sequences to generate operational taxonomic units (OTUs). Phylogenetic inferences were made through analyses of both molecular data sets. A total of 48 OTUs from spore mats represented six independent EcM Pezizales lineages and included truffles and cup fungi. Three clades of seven OTUs have no known meiospore stage. Mitospores failed to germinate on sterile media, or form ectomycorrhizas on Quercus, Pinus and Populus seedlings, consistent with a hypothesized role of spermatia. The broad geographic range, high frequency and phylogenetic diversity of spore mats produced by EcM Pezizales suggests that a mitospore stage is important for many species in this group in terms of mating, reproduction and/or dispersal. PMID:23205556

  18. Microscale characterization of dissolved organic matter production and uptake in marine microbial mat communities

    Science.gov (United States)

    Paerl, H. W.; Bebout, B. M.; Joye, S. B.; Des Marais, D. J.

    1993-01-01

    Intertidal marine microbial mats exhibited biologically mediated uptake of low molecular weight dissolved organic matter (DOM), including D-glucose, acetate, and an L-amino acid mixture at trace concentrations. Uptake of all compounds occurred in darkness, but was frequently enhanced under natural illumination. The photosystem 2 inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU) generally failed to inhibit light-stimulated DOM uptake. Occasionally, light plus DCMU-amended treatments led to uptake rates higher than light-incubated samples, possibly due to phototrophic bacteria present in subsurface anoxic layers. Uptake was similar with either 3H- or 14C-labeled substrates, indicating that recycling of labeled CO2 via photosynthetic fixation was not interfering with measurements of light-stimulated DOM uptake. Microautoradiographs showed a variety of pigmented and nonpigmented bacteria and, to a lesser extent, cyanobacteria and eucaryotic microalgae involved in light-mediated DOM uptake. Light-stimulated DOM uptake was often observed in bacteria associated with sheaths and mucilage surrounding filamentous cyanobacteria, revealing a close association of organisms taking up DOM with photoautotrophic members of the mat community. The capacity for dark- and light-mediated heterotrophy, coupled to efficient retention of fixed carbon in the mat community, may help optimize net production and accretion of mats, even in oligotrophic waters.

  19. Carbon and Oxygen Budgets of Hypersaline Cyanobacterial Mats: Effects of Tidal Cycle and Temperature

    Science.gov (United States)

    DesMarais, David J.; Bebout, Brad M.; Carpenter, Steven; Discipulo, Mykell; Turk, Kendra

    2003-01-01

    The hierarchical organization of microbial ecosystems determines the rates of processes that shape Earth#s environment, define the stage upon which major evolutionary events occurred, and create biosignatures in sediments and atmospheres. In cyanobacterial mats, oxygenic photosynthesis provides energy, organic substrates and oxygen to the ecosystem. Incident light changes with depth in the mat, both in intensity and spectral composition, and counteracting gradients of oxygen and sulfide shape the chemical microenvironment. A combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods and to various depths in the mat. Microbiota produce hydrogen, small organic acids, and nitrogen and sulfur species. Such compounds fuel a flow of energy and electrons in these ecosystems and thus shape interactions between groups of microorganisms. Coordinated observations of population distribution, abundance, and activity for an entire community are making fundamental questions in ecology accessible. These questions address those factors that sustain the remarkable diversity of microorganisms that are now being revealed by molecular techniques. These questions also target the processes that shape the various kinds of biosignatures that we will seek, both in ancient rocks from Earth and Mars, and in atmospheres of distant planets beyond our Solar System.

  20. Welcome address / Mats Estonius, Toomas Hendrik Ilves, Eduardo Ibàñes, Uffe A. Baslev

    Index Scriptorium Estoniae

    2010-01-01

    Läänemere strateegia konverentsi avasõnad laususid Tallinna Ülikooli teadusprorektor Mats Estonius, Eesti Vabariigi president Toomas Hendrik Ilves ((vt. ka foto lk. 21), Hispaania Kuningriigi suursaadik Eestis Eduardo Ibáñes ja Taani Kuningriigi suursaadik Eestis Uffe A. Baslev

  1. T-MATS Toolbox for the Modeling and Analysis of Thermodynamic Systems

    Science.gov (United States)

    Chapman, Jeffryes W.

    2014-01-01

    The Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) is a MATLABSimulink (The MathWorks Inc.) plug-in for creating and simulating thermodynamic systems and controls. The package contains generic parameterized components that can be combined with a variable input iterative solver and optimization algorithm to create complex system models, such as gas turbines.

  2. Fabrication of Ag nanoparticles dispersed in PVA nanowire mats by microwave irradiation and electro-spinning

    International Nuclear Information System (INIS)

    In this study, the antimicrobial substance, silver nanoparticles (Ag NPs) loaded in poly (vinyl alcohol) (PVA) nanowire mats were fabricated by conjugation of the electro-spinning method and the microwave-assisted process. The best PVA nanowire mats were fabricated by through control of electro-spinning conditions, which were applied for fabrication of Ag NPs loaded in PVA nanowires. PVA was used not only as a carrier for loading of Ag NPs but also as a reduction agent with which the Ag+ ion was already reduced to a large number of Ag NPs by irradiation with a microwave. Ag NPs were synthesized inside the PVA solution depending on the time of microwave irradiation - whether for 60 s or 90 s. Size distribution of Ag NPs was 5-10 nm in diameter for 60 s; and 10-20 nm in diameter for 90 s of irradiation. Presence of Ag NPs acquired through microwave assisted irradiation was confirmed by X-ray diffraction profiles (XRD). Microstructure, particle size distribution, and morphology of both the nanowire mats and the Ag particles were investigated using SEM and TEM techniques. The effect of Ag-NPs on the PVA mechanical property of nano-fibrous mats was investigated according to tensile strength. Antibacterial activity of PVA loaded Ag NPs at different irradiation times was tested on Gram-positive bacteria, Staphylococcus aureus Gram-negative bacteria, and Escherichia coli.

  3. The Effectiveness of Talking Mats[R] with People with Intellectual Disability

    Science.gov (United States)

    Murphy, Joan; Cameron, Lois

    2008-01-01

    People with intellectual disability have significant difficulties in ensuring their voice is heard. Talking Mats is a low tech communication resource which helps understanding and supports expression. This study examined the effectiveness of the resource for people with intellectual disability. A mixed method quantitative and qualitative study…

  4. Using the 4MAT Framework to Design a Problem-Based Learning Biostatistics Course

    Science.gov (United States)

    Nowacki, Amy S.

    2011-01-01

    The study presents and applies the 4MAT theoretical framework to educational planning to transform a biostatistics course into a problem-based learning experience. Using a four-question approach, described are specific activities/materials utilized at both the class and course levels. Two web-based instruments collected data regarding student…

  5. Nitrogen fixation in a non-heterocystous cyanobacterial mat from a mountain river

    Science.gov (United States)

    Berrendero, Esther; Valiente, Eduardo Fernández; Perona, Elvira; Gómez, Claudia L.; Loza, Virginia; Muñoz-Martín, M. Ángeles; Mateo, Pilar

    2016-01-01

    In situ nitrogen fixation was investigated in a cyanobacterial mat growing on the bed of rocks of the Muga River, Spain. The filamentous non-heterocystous cyanobacterium Schizothrix dominated the mat, showing nitrogenase activity in the light at similar rates to those found in nearby heterocystous Rivularia colonies. N2 fixation in the light was significantly increased by an inhibitor of PSII and oxygen evolution, DCMU (3-[3,4-dichlorophenyl]-1,1-dimethylurea), and anaerobic conditions. However, no nitrogenase activity was found in the dark. Addition of fructose as a respiratory substrate induced nitrogenase activity in samples incubated under aerobic conditions in the dark but not in anaerobic conditions. Microelectrode oxygen profiles showed internal microaerobic microzones where nitrogen fixation might concentrate. Analyses of the 16S rRNA gene revealed only the presence of sequences belonging to filamentous non-heterocystous cyanobacteria. nifH gene diversity showed that the major phylotypes also belonged to this group. One of the three strains isolated from the Schizothrix mat was capable of fixing N2 and growing in the absence of combined N. This was consistent with the nifH gene analysis. These results suggest a relevant contribution of non-heterocystous cyanobacteria to nitrogen fixation in these mats. PMID:27476439

  6. Formation and Fate of Fermentation Products in Hot Spring Cyanobacterial Mats

    OpenAIRE

    Anderson, Karen L.; Tayne, Timothy A.; Ward, David M.

    1987-01-01

    The fate of representative fermentation products (acetate, propionate, butyrate, lactate, and ethanol) in hot spring cyanobacterial mats was investigated. The major fate during incubations in the light was photoassimilation by filamentous bacteria resembling Chloroflexus aurantiacus. Some metabolism of all compounds occurred under dark aerobic conditions. Under dark anaerobic conditions, only lactate was oxidized extensively to carbon dioxide. Extended preincubation under dark anaerobic condi...

  7. Eight-Week Traditional Mat Pilates Training-Program Effects on Adult Fitness Characteristics

    Science.gov (United States)

    Rogers, Kate; Gibson, Ann L.

    2009-01-01

    We investigated responses of adult, novice practitioners (n = 9) to an 8-week traditional mat Pilates program (P) that met 1 hr/day three times/week. Classes consisted primarily of beginner and intermediate level exercises. Compared to an active control group (C; n = 13) that showed no improvements, those in P significantly (p less than 0.05)…

  8. Fabrication of Ag nanoparticles dispersed in PVA nanowire mats by microwave irradiation and electro-spinning

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thi-Hiep [Department of Biomedical Engineering and Materials, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Lee, Kap-Ho [School of Advanced Materials Engineering, Chungnam National University, Yuseong-gu, Daejon 305 (Korea, Republic of); Lee, Byong-Taek, E-mail: lbt@sch.ac.kr [Department of Biomedical Engineering and Materials, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of)

    2010-08-30

    In this study, the antimicrobial substance, silver nanoparticles (Ag NPs) loaded in poly (vinyl alcohol) (PVA) nanowire mats were fabricated by conjugation of the electro-spinning method and the microwave-assisted process. The best PVA nanowire mats were fabricated by through control of electro-spinning conditions, which were applied for fabrication of Ag NPs loaded in PVA nanowires. PVA was used not only as a carrier for loading of Ag NPs but also as a reduction agent with which the Ag{sup +} ion was already reduced to a large number of Ag NPs by irradiation with a microwave. Ag NPs were synthesized inside the PVA solution depending on the time of microwave irradiation - whether for 60 s or 90 s. Size distribution of Ag NPs was 5-10 nm in diameter for 60 s; and 10-20 nm in diameter for 90 s of irradiation. Presence of Ag NPs acquired through microwave assisted irradiation was confirmed by X-ray diffraction profiles (XRD). Microstructure, particle size distribution, and morphology of both the nanowire mats and the Ag particles were investigated using SEM and TEM techniques. The effect of Ag-NPs on the PVA mechanical property of nano-fibrous mats was investigated according to tensile strength. Antibacterial activity of PVA loaded Ag NPs at different irradiation times was tested on Gram-positive bacteria, Staphylococcus aureus Gram-negative bacteria, and Escherichia coli.

  9. Producció de matèries primeres. Curs 2007-2008

    OpenAIRE

    Universitat de Barcelona. Facultat de Farmàcia

    2007-01-01

    Pla docent de l'assignatura Producció de matèries primeres de l'Ensenyament de Ciència i Tecnologia dels Aliments. Curs acadèmic 2007-2008. Departament de Productes Naturals, Biologia Vegetal i Edafologia.

  10. Producció de matèries primeres. Curs 2008-2009

    OpenAIRE

    Universitat de Barcelona. Facultat de Farmàcia

    2008-01-01

    Pla docent de l'assignatura Producció de matèries primeres de l'Ensenyament de Ciència i Tecnologia dels Aliments. Curs acadèmic 2008-2009. Departament Productes Naturals, Biologia Vegetal i Edafologia.

  11. Producció de matèries primeres. Curs 2006-2007

    OpenAIRE

    Universitat de Barcelona. Facultat de Farmàcia

    2006-01-01

    Pla docent de l'assignatura Producció de matèries primeres de l'Ensenyament de Ciència i Tecnologia dels Aliments. Curs acadèmic 2006-2007. Departaments de Productes Naturals, Biologia Vegetal i Edafologia (UB)/ Ciència animal i dels Aliments (UAB)

  12. Producció de matèries primeres. Curs 2005-2006

    OpenAIRE

    Universitat de Barcelona. Facultat de Farmàcia

    2005-01-01

    Pla docent de l'assignatura Producció de matèries primeres de l'Ensenyament de Ciència i Tecnologia dels Aliments. Curs acadèmic 2005-2006. Departament de Productes Naturals, Biologia Vegetal i Edafologia.

  13. Organic matter degradation drives benthic cyanobacterial mat abundance on caribbean coral reefs

    NARCIS (Netherlands)

    Brocke, Hannah J.; Polerecky, Lubos; De Beer, Dirk; Weber, Miriam; Claudet, Joachim; Nugues, Maggy M.

    2015-01-01

    Benthic cyanobacterial mats (BCMs) are impacting coral reefs worldwide. However, the factors and mechanisms driving their proliferation are unclear. We conducted a multi-year survey around the Caribbean island of Curaçao, which revealed highest BCM abundance on sheltered reefs close to urbanised are

  14. The Use of Maltodextrin Matrices to Control the Release of Minerals from Fortified Maté

    Directory of Open Access Journals (Sweden)

    Miguel E. Schmalko

    2012-04-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE The aim of this research was to study the sensorial acceptance of a fortified food containing different minerals (calcium, magnesium and iron and to determine the actual quantities present (bioaccessibility when extracted in maté. A sensorial analysis was performed to compare sensorial quality of fortified and non-fortified maté. Although panelists identified differences between the fortified and non-fortified maté, only 3% of them commented on an unpleasant flavor. Sequential extraction assays were performed simulating maté consumption under laboratory conditions. Profile concentration diminished sharply after the second extraction. Magnesium was found to be completely extracted in the first 500 mL. Calcium and Iron were extracted in a very low percentage (29% and 25%, respectively. The outlet rate of the minerals was fitted to two models, and a good fitness (p < 0:001 in all cases was obtained.

  15. Spatial and temporal changes in phosphorus partitioning within a freshwater cyanobacterial mat community

    Czech Academy of Sciences Publication Activity Database

    Borovec, Jakub; Sirová, D.; Mošnerová, Petra; Rejmánková, E.; Vrba, J.

    2010-01-01

    Roč. 101, 1-3 (2010), s. 323-333. ISSN 0168-2563 R&D Projects: GA MZe(CZ) QH81012 Institutional research plan: CEZ:AV0Z60170517; CEZ:AV0Z60050516 Keywords : phosphorus partitioning * cyanobacterial mat * diurnal changes * sequential fractionation * EPS Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.674, year: 2010

  16. A Cyanine Dye Encapsulated Porous Fibrous Mat for Naked-Eye Ammonia Sensing.

    Science.gov (United States)

    Ji, Chendong; Ma, Lijing; Yin, Meizhen; Yang, Wantai; Pan, Kai

    2016-08-19

    Electrospun ultrathin fiber-based sensors are desirable because of their practicality and sensitivity. Ammonia-detection systems are in high demand in different areas, including the industrial and agricultural fields. However, current technologies rely on large and complex instruments that restrict their actual utilization. Herein, we report a flexible naked-eye ammonia sensor, the polylactic acid-cyanine (PLA-Cy) fibrous mat, which was fabricated by blending a carboxyl-functionalized cyanine dye (D1) into electospun PLA porous fibers. The sensing mat was shown to undergo a naked-eye-detectable color change from white to blue upon exposure to ammonia vapor. The mat showed high selectivity to ammonia gas with a detection limit of 3.3 ppm. Aggregated D1 was first encapsulated by PLA and was then ionized by NH3 . These mechanisms were examined by photophysical studies and scanning electron microscopy. The aggregation-deaggregation process of D1 in the PLA-Cy fibrous mat led to the color change. This work provides a facile method for the naked-eye detection of ammonia and a novel strategy for the use of organic dyes in ammonia sensing. PMID:27411059

  17. Potentiality evaluation of the MAT 250 UF mass spectrometer for general analysis

    International Nuclear Information System (INIS)

    This work presents a study on the potentiality of the MAT 250 UF mass spectrometer. It was formerly used only, for uranium isotopic analysis. It will be used, flow now on, also for the analysis of other gases such as deuterium, helium and hydrogen, as well. (A.C.A.S.)

  18. Nitrogen fixation in a non-heterocystous cyanobacterial mat from a mountain river

    Science.gov (United States)

    Berrendero, Esther; Valiente, Eduardo Fernández; Perona, Elvira; Gómez, Claudia L.; Loza, Virginia; Muñoz-Martín, M. Ángeles; Mateo, Pilar

    2016-08-01

    In situ nitrogen fixation was investigated in a cyanobacterial mat growing on the bed of rocks of the Muga River, Spain. The filamentous non-heterocystous cyanobacterium Schizothrix dominated the mat, showing nitrogenase activity in the light at similar rates to those found in nearby heterocystous Rivularia colonies. N2 fixation in the light was significantly increased by an inhibitor of PSII and oxygen evolution, DCMU (3-[3,4-dichlorophenyl]-1,1-dimethylurea), and anaerobic conditions. However, no nitrogenase activity was found in the dark. Addition of fructose as a respiratory substrate induced nitrogenase activity in samples incubated under aerobic conditions in the dark but not in anaerobic conditions. Microelectrode oxygen profiles showed internal microaerobic microzones where nitrogen fixation might concentrate. Analyses of the 16S rRNA gene revealed only the presence of sequences belonging to filamentous non-heterocystous cyanobacteria. nifH gene diversity showed that the major phylotypes also belonged to this group. One of the three strains isolated from the Schizothrix mat was capable of fixing N2 and growing in the absence of combined N. This was consistent with the nifH gene analysis. These results suggest a relevant contribution of non-heterocystous cyanobacteria to nitrogen fixation in these mats.

  19. Community ecology of hot spring cyanobacterial mats: predominant populations and their functional potential

    DEFF Research Database (Denmark)

    Klatt, C. G.; Wood, J. M.; Rusch, D. B.;

    2011-01-01

    Phototrophic microbial mat communities from 60¿°C and 65¿°C regions in the effluent channels of Mushroom and Octopus Springs (Yellowstone National Park, WY, USA) were investigated by shotgun metagenomic sequencing. Analyses of assembled metagenomic sequences resolved six dominant chlorophototrophic...

  20. Base mat uplift effects on the seismic response of a rectangular nuclear building

    International Nuclear Information System (INIS)

    This contribution presents results of a seismic analysis of a rectangular building subjected to an earthquake in its weak direction with special regard to nonlinear base mat uplift effects. A nuclear power plant switchgear building, is assumed to be located in the Upper Rhine Graben, which belongs to the highest German earthquake zones. The peak ground acceleration based is 0.3 g. A linear earthquake analysis predicted that more than 50% of the area of the base mat would uplift off the supporting soil. For the state of maximum uplift conditions, a static analysis of the building subjected to the gravity loads of the lifted-off building parts would lead to high shear and tensile forces in the concrete walls, which would require an extreme amount of reinforcement. A nonlinear earthquake analysis was performed considering the nonlinear relationship - overturning moment vs. base rotation - in order to give an adequate estimate of the amount of base mat uplift and internal forces in the walls. Nonlinearities due to the decreasing contact area between base mat and soil were considered taking also into account the time-dependency of the vertical load component due to vertical vibrations. (orig./HP)

  1. Acquisition systems and data elaboration for Varian Mat 1129 mass spectrometers

    International Nuclear Information System (INIS)

    The data acquisition equipment to be described is used to capture data deriving from the Varian Mat 1125 mass spectrometer. It is based on a system controlled by the microprocessor 8085 and was designed with the aim of advantegeously replacing the photosensitive paper recorder used originally. (Author)

  2. Persistent Giardia spp. and Trichuris spp. infection in maras (Dolichotis patagonum) at a zoo in Greece.

    Science.gov (United States)

    Tahas, Stamatios Alan; Diakou, Anastasia

    2013-06-01

    The mara (Dolichotis patagonum) is a species classified as "Near Threatened" by the International Union for Conservation of Nature. In the wild, it inhabits only Argentina, but it is also kept in zoos around the world. In order to investigate the endoparasites of the maras kept in the Attica Zoological Park, Greece, four fecal examinations were performed in a period of 4 yr (2008-2011) by standard parasitologic methods. Cysts of the protozoan parasite Giardia spp. and eggs of the nematode Trichuris spp. were found in all four examinations. The possible routes of infection of the maras and the importance of these parasites to other animals and to humans are discussed. PMID:23805557

  3. Microbial mats of the Tswaing impact crater: results of a South African exobiology expedition and implications for the search for biological molecules on Mars

    OpenAIRE

    Cockell, C. S.; Brandt, D. (Dieter); Hand, K.; Lee, P C

    2001-01-01

    We describe microbial mats from the Tswaing impact crater in South Africa. The mats provide insights into the unique biological characteristics of impact craters and can help strategies for the search for biomolecules on Mars.

  4. Biocontrol of Rhizoctonia solani with Trichoderma Spp.

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ From over 800 fungal strains of Trichoderma Spp. , 6 strains were found to greatly inhibit the growing of Rhizocotonia solani, the pathogen of rice sheath blight in dual culture. Among them, strain T3 was the best antagonist,which reduced the growing of the pathogen by 52.54% (Table 1). In field, both the pesticide Jinggangmycin and the mixture of T1 T6 could reduce the severity of rice sheath blight(Table 2), which resulted in the increases of seed setting rate and 1000 grain weight. Because the effect of the antagonists on the control of the pathogen could be partially realized in the watery environment, studies on the biocontrol mechanism of the fungi should be strengthened to help the establishment of a best way of antagonist utilization.

  5. SOIL FAUNA CHARACTERIZATION IN Eucalyptus spp. PLANTATIONS

    Directory of Open Access Journals (Sweden)

    Juliana Garlet

    2013-08-01

    Full Text Available http://dx.doi.org/10.5902/1980509810545Forest soils provide good conditions for the development and the establishment of soil fauna, manly by the deposition of litter. However, monoculture systems conducted in a single substrate by providing food, can promote the development of certain animal groups over others, causing outbreaks of pest species. The aim of this study was to characterize the soil fauna and its relationship with meteorological variables, in plantations of Eucalyptus spp. This study was conducted in six stands of Eucalyptus from three species: Eucalyptus dunni Maiden, Eucalyptus grandis Maiden and Eucalyptus grandis x Eucalyptus urophylla S. T. Blake (clone hybrid and two ages (planted in 2006 and 2007.

  6. Design Studies with DEMIRCI for SPP RFQ

    CERN Document Server

    Yasatekin, B; Alacakir, A; Unel, G

    2014-01-01

    To design a Radio Frequency Quadrupole (RFQ) is a onerous job which requires a good understanding of all the main parameters and the relevant calculations. Up to the present there are only a few software packages performing this task in a reliable way. These legacy software, though proven in time, could benefit from the modern software development tools like Object Oriented (OO) programming. In this note, a new RFQ design software, DEMIRCI is introduced. It is written entirely from scratch using C++ and based on CERN's OO ROOT library. It has a friendly graphical user interface and also a command line interface for batch calculations. It can also interact by file exchange with similar software in the field. After presenting the generic properties of DEMIRCI, its compatibility with similar software packages is discussed based on the results from the reference design parameters of SPP (SNRTC Project Prometheus), a demonstration accelerator at Ankara, Turkey.

  7. A Biofilm Treatment Approach for Produced Water from Hydraulic Fracturing Using Engineered Microbial Mats

    Science.gov (United States)

    Akyon, B.; Stachler, E.; Bibby, K. J.

    2015-12-01

    Hydraulic fracturing results in large volumes of wastewater, called "produced water". Treatment of produced water is challenged by its high salt, organic compound, and radionuclide concentrations. Current disposal approaches include deep well injection and physical-chemical treatment for surface disposal; however, deep well injection has been recently linked to induced seismicity and physical-chemical treatments suffer from fouling and high cost. The reuse of the produced water has emerged as a desirable management option; however, this requires pretreatment to generate a water of usable quality and limit microbial activity. Biological treatment is an underexplored area in produced water management and has the potential to remove organics and reduce overall costs for physiochemical treatment or reuse. Suspended growth biological treatment techniques are known to be limited by salinity motivating a more robust biofilm approach: 'microbial mats'. In this study, we used engineered microbial mats as a biofilm treatment for the produced water. Evaluation of the biodegradation performance of microbial mats in synthetic and real produced waters showed microbial activity at up to 100,000 mg/L TDS concentration (three times the salt concentration of the ocean). Organic removal rates reached to 1.45 mg COD/gramwet-day at 91,351 mg/L TDS in real produced water samples and initial evaluation demonstrated the potential for field-scale application. Metagenomic analyses of microbial mats demonstrated an adaptive shift in the microbial community treating different samples, suggesting the wide applicability of this treatment approach for produced waters with varying chemical composition. On-going studies focus on the evaluation of the removal of the organics and the contaminants of high concern in produced water using microbial mats as well as the effect of the biofilm growth conditions on the biodegradation in changing salt concentrations.

  8. Learning Geomicrobiology as a Team Using Microbial Mats, a Multidisciplinary Approach

    Directory of Open Access Journals (Sweden)

    Carlos Rios-Velazquez

    2009-12-01

    Full Text Available Microbial mats are one of the best suited laminar organo-sedimentary ecosystems for students from different educational backgrounds to visualize the direct relationship between microbes and minerals. We have used tropical hypersaline microbial mats from Puerto Rico as educational tools to promote active learning of geomicrobiology introductory concepts for undergraduate students organized in multidisciplinary teams with biological and geological backgrounds. Besides field trips and independent research projects focused on microbial mats, four intensive workshops and one capstone activity were designed to expose students to the different geomicrobiology subdisciplines (microbiology, molecular biology, geology, and geochemistry. The teaching-learning process was assessed using pre- and posttests, group discussions, activities including Gallery Walks and exquisite cadaver’s, case studies, and focal interviews. While the posttest showed a significant difference in conceptual understanding, the Gallery Walk and the capstone activities demonstrated increase in the depth, coherence, and thoughtfulness in answering questions, including a clear integration of the different subdisciplines during their presentations. Finally, the main themes described by the students as important outcomes of their participation in the Research at Undergraduate Institutions: Microbial Observatory (RUI-MO program were: (i the opportunity to study and learn new and different science disciplines, (ii the microbial mats were excellent tools to learn from and integrate different science disciplines, and (iii working in multidisciplinary teams gave them the opportunity to learn from their peers’ discipline backgrounds. To our knowledge this is the first educational initiative that uses tropical hypersaline microbial mats to teach geomicrobiology in a multidisciplinary fashion.

  9. Learning Geomicrobiology as a Team Using Microbial Mats, a Multidisciplinary Approach

    Directory of Open Access Journals (Sweden)

    Pieter T. Visscher

    2007-12-01

    Full Text Available Microbial mats are one of the best suited laminar organo-sedimentary ecosystems for students from different educational backgrounds to visualize the direct relationship between microbes and minerals. We have used tropical hypersaline microbial mats from Puerto Rico as educational tools to promote active learning of geomicrobiology introductory concepts for undergraduate students organized in multidisciplinary teams with biological and geological backgrounds. Besides field trips and independent research projects focused on microbial mats, four intensive workshops and one capstone activity were designed to expose students to the different geomicrobiology subdisciplines (microbiology, molecular biology, geology, and geochemistry. The teaching-learning process was assessed using pre- and posttests, group discussions, activities including Gallery Walks and exquisite cadaver’s, case studies, and focal interviews. While the posttest showed a significant difference in conceptual understanding, the Gallery Walk and the capstone activities demonstrated increase in the depth, coherence, and thoughtfulness in answering questions, including a clear integration of the different subdisciplines during their presentations. Finally, the main themes described by the students as important outcomes of their participation in the Research at Undergraduate Institutions: Microbial Observatory (RUI-MO program were: (i the opportunity to study and learn new and different science disciplines, (ii the microbial mats were excellent tools to learn from and integrate different science disciplines, and (iii working in multidisciplinary teams gave them the opportunity to learn from their peers’ discipline backgrounds. To our knowledge this is the first educational initiative that uses tropical hypersaline microbial mats to teach geomicrobiology in a multidisciplinary fashion.

  10. Quantitative Relationships between Photosynthetic, Nitrogen Fixing, and Fermentative H2 Metabolism in a Photosynthetic Microbial Mat

    Science.gov (United States)

    Hoehler, Tori M.; Albert, Daniel B.; Bebout, Brad M.; Turk, Kendra A.; DesMarais, David J.

    2004-01-01

    The ultimate potential of any microbial ecosystem to contribute chemically to its environment - and therefore, to impact planetary biogeochemistry or to generate recognizable biosignatures - depends not only on the individual metabolic capabilities of constituent organisms, but also on how those capabilities are expressed through interactions with neighboring organisms. This is particularly important for microbial mats, which compress an extremely broad range of metabolic potential into a small and dynamic system. H2 participates in many of these metabolic processes, including the major elemental cycling processes of photosynthesis, nitrogen fixation, sulfate reduction, and fermentation, and may therefore serve as a mediator of microbial interactions within the mat system. Collectively, the requirements of energy, electron transfer, and biomass element stoichiometry suggest quantitative relationships among the major element cycling processes, as regards H2 metabolism We determined experimentally the major contributions to 32 cycling in hypersaline microbial mats from Baja California, Mexico, and compared them to predicted relationships. Fermentation under dark, anoxic conditions is quantitatively the most important mechanism of H2 production, consistent with expectations for non-heterocystous mats such as those under study. Up to 16% of reducing equivalents fixed by photosynthesis during the day may be released by this mechanism. The direct contribution of nitrogen fixation to H2 production is small in comparison, but this process may indirectly stimulate substantial H2 generation, by requiring higher rates of fermentation. Sulfate reduction, aerobic consumption, diffusive and ebulitive loss, and possibly H2-based photoreduction of CO2 serve as the principal H2 sinks. Collectively, these processes interact to create an orders-of-magnitude daily variation in H2 concentrations and fluxes, and thereby in the oxidation-reduction potential that is imposed on microbial

  11. Biodiversity within hot spring microbial mat communities: molecular monitoring of enrichment cultures

    Science.gov (United States)

    Ward, D. M.; Santegoeds, C. M.; Nold, S. C.; Ramsing, N. B.; Ferris, M. J.; Bateson, M. M.

    1997-01-01

    We have begun to examine the basis for incongruence between hot spring microbial mat populations detected by cultivation or by 16S rRNA methods. We used denaturing gradient gel electrophoresis (DGGE) to monitor enrichments and isolates plated therefrom. At near extincting inoculum dilutions we observed Chloroflexus-like and cyanobacterial populations whose 16S rRNA sequences have been detected in the 'New Pit' Spring Chloroflexus mat and the Octopus Spring cyanobacterial mat. Cyanobacterial populations enriched from 44 to 54 degrees C and 56 to 63 degrees C samples at near habitat temperatures were similar to those previously detected in mat samples of comparable temperatures. However, a lower temperature enrichment from the higher temperature sample selected for the populations found in the lower temperature sample. Three Thermus populations detected by both DGGE and isolation exemplify even more how enrichment may bias our view of community structure. The most abundant population was adapted to the habitat temperature (50 degrees C), while populations adapted to 65 degrees C and 70 degrees C were 10(2)- and 10(4)-fold less abundant, respectively. However, enrichment at 70 degrees C favored the least abundant strain. Inoculum dilution and incubation at the habitat temperature favored the more numerically relevant populations. We enriched many other aerobic chemoorganotrophic populations at various inoculum dilutions and substrate concentrations, most of whose 16S rRNA sequences have not been detected in mats. A common feature of numerically relevant cyanobacterial, Chloroflexus-like and aerobic chemorganotrophic populations, is that they grow poorly and resist cultivation on solidified medium, suggesting plating bias, and that the medium composition and incubation conditions may not reflect the natural microenvironments these populations inhabit.

  12. Listeria spp. no processamento de lingüiça frescal em frigoríficos de Pelotas, RS, Brasil Listeria spp. in the processing of fresh sausages in slaughterhou ses from Pelotas, RS, Brazil

    Directory of Open Access Journals (Sweden)

    Wladimir Padilha da Silva

    2004-06-01

    Full Text Available Alimentos intensamente manipulados, como as lingüiças mistas do tipo frescal são freqüentemente responsáveis pela veiculação de enfermidades transmitidas por alimentos. Devido ao risco à saúde pública que a bactéria Listeria monocytogenes representa, este trabalho teve como objetivo estudar a presença de Listeria spp., em especial de L. monocytogenes, durante o processamento de lingüiças mistas do tipo frescal, em três frigoríficos com inspeção sanitária estadual, em Pelotas-RS. Para isso, analisou-se a matéria-prima utilizada no preparo da lingüiça, os equipamentos da linha de processamento e o produto final. Isolou-se Listeria spp. em 100% das 41 amostras analisadas, nos 3 estabelecimentos estudados. Dentre as diferentes espécies, L. innocua foi aquela isolada com maior freqüência, em 97,6% das amostras, seguida por L. monocytogenes em 29,3% e L. welshimeri em 24,4%. A presença destes microrganismos nas amostras analisadas, em especial no produto final, demonstra a necessidade de readequação nas práticas de limpeza e sanificação das plantas de processamento analisadas, bem como representa risco potencial de listeriose ao consumidor.Food that is highly manipulated, such as fresh sausages, is frequently responsible for spreading food borne diseases. Due to the threat that the bacterium Listeria monocytogenes represents to public health, the aim of this work was to study the presence of Listeria spp., especially Listeria monocytogenes, during processing of fresh sausages, in three slaughterhouses with state food inspection, in the city of Pelotas, Brazil. The raw material used for the sausage elaboration, the equipment used in the processing and the end products were analyzed. The results showed Listeria spp. in 100% of the 41 samples analyzed. Among the different species, L. innocua was the most frequent, isolated from 97.6% of the samples, followed by the L. monocytogenes and L. welshimeri that were isolated from

  13. Impacto de herbicidas em isolados de Trichoderma spp. Impact of herbicides on strains of Trichoderma spp.

    Directory of Open Access Journals (Sweden)

    M.R. Reis

    2013-06-01

    Full Text Available O uso de microrganismos é uma alternativa para o controle de doenças em plantas. Todavia, é prudente verificar a interação desse com os demais métodos de controle empregados em determinada cultura. Dessa forma, objetivou-se avaliar a fungitoxicidade dos herbicidas sobre o crescimento e desenvolvimento dos isolados de Trichoderma spp. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 6 x 6 x 4, com quatro repetições. O fator A correspondeu aos herbicidas pendimethalin, clomazone, carfentrazone-ethyl, oxadiazon, thiobencarb + propanil e byspiribac-sodium; o fator B, às doses dos herbicidas - 0, 25, 50, 75, 100 e 200% da dose recomendada; e o fator C, aos isolados de Trichoderma spp. AJAM 18, CE 66, TRI 01 e TRI 02. O ensaio foi realizado em condições in vitro; avaliaram-se o crescimento micelial radial (CMR e a esporulação dos isolados após aplicação dos herbicidas. Observaram-se diferenças de sensibilidade dos isolados para o mesmo produto testado. O oxadiazon reduziu o CMR dos isolados AJAM 18 e TRI 01 em 66 e 35%, respectivamente. No entanto, reduziu apenas 16% do CMR do isolado TRI 02 e não alterou o CMR do isolado CE 66 mesmo em 200% da dose recomendada. Verificaram-se diferentes efeitos dos produtos em cada isolado. A mistura comercial de thiobencarb+propanil foi altamente tóxica aos isolados de Trichoderma spp., com reduções em torno de 85% no CMR e no número de esporos. Por outro lado, o byspiribac-sodium pouco afetou os isolados, apresentando reduções inferiores a 10% no CMR e na esporulação. O carfentrazone-ethyl e byspiribac-sodium demonstraram ser compatíveis com os isolados de Trichoderma spp. estudados.The use of microorganisms is an alternative for the control of plant diseases. However, one should verify its interaction with other methods of control used for a particular crop. The objective of this work was to evaluate the effect of herbicide fungitoxicity on the growth and

  14. [Soil contamination with Toxocara spp. eggs in the Elblag area].

    Science.gov (United States)

    Jarosz, W

    2001-01-01

    The distribution of Toxocara spp. eggs in Elbl4g was studied. Out of 72 soil samples collected in public places of the city 13.9% were positive and the mean egg density was 3.75/100g soil. The city backyards were much more contaminated with Toxocara spp. eggs (18.0%) than the playgrounds (4.5%). In sandpits examined the eggs were not found. Almost 80% of Toxocara spp. eggs recovered were infective. T. cati eggs were more frequent than T. canis eggs. Additionally in examined samples two eggs of Ancylostoma caninum and one egg of Ascaris lumbricoides were recognized. PMID:16888965

  15. A simple method for DNA isolation from Xanthomonas spp.

    Directory of Open Access Journals (Sweden)

    Gomes Luiz Humberto

    2000-01-01

    Full Text Available A simple DNA isolation method was developed with routine chemicals that yields high quality and integrity preparations when compared to some of the most well known protocols. The method described does not require the use of lysing enzymes, water bath and the DNA was obtained within 40 minutes The amount of nucleic acid extracted (measured in terms of absorbancy at 260 nm from strains of Xanthomonas spp., Pseudomonas spp. and Erwinia spp. was two to five times higher than that of the most commonly used method.

  16. Chemical and ecological control methods for Epitrix spp.

    Directory of Open Access Journals (Sweden)

    A. G. S. Cuthbertson

    2015-01-01

    Full Text Available Very little information exists in regards to the control options available for potato flea beetles, Epitrix spp. This short review covers both chemical and ecological options currently available for control of Epitrix spp. Synthetic pyrethroids are the weapon of choice for the beetles. However, the impetus in integrated pest management is to do timely (early-season applications with something harsh which will give long-term protection at a time when there are not a lot of beneficials in the field. Finding the balance for control of Epitrix spp. is proving difficult.

  17. Statistical Analysis of Charpy Transition Temperature Shift in Reactor Pressure Vessel Steels: Application of Nuclear Materials Database(MatDB)

    International Nuclear Information System (INIS)

    The MDPortal contains various technical documents on the degradation and development of nuclear materials. Additionally, the nuclear materials database (MatDB) is also launched in KAERI recently. The MatDB covers the mechanical properties of various nuclear structural materials used as the components: a reactor pressure vessel, steam generator, and primary and secondary piping. In this study, we introduced MatDB briefly, and analyzed the Charpy transition temperature shift in reactor pressure vessel steels of Korean nuclear power plants retrieved from MatDB. It can show an application of the MatDB to the real case of material degradations in NPPs. The MatDB includes the tensile results, Charpy results, fatigue results and J-R curve results at present. In the future other properties such as creep, fracture toughness, and SCC degradations are going to be added consistently. The data from MatDB were successfully applied to estimate the TTS analysis of Korean RPV steels in surveillance tests

  18. Dynamics of bacterial populations during bench-scale bioremediation of oily seawater and desert soil bioaugmented with coastal microbial mats.

    Science.gov (United States)

    Ali, Nidaa; Dashti, Narjes; Salamah, Samar; Sorkhoh, Naser; Al-Awadhi, Husain; Radwan, Samir

    2016-03-01

    This study describes a bench-scale attempt to bioremediate Kuwaiti, oily water and soil samples through bioaugmentation with coastal microbial mats rich in hydrocarbonoclastic bacterioflora. Seawater and desert soil samples were artificially polluted with 1% weathered oil, and bioaugmented with microbial mat suspensions. Oil removal and microbial community dynamics were monitored. In batch cultures, oil removal was more effective in soil than in seawater. Hydrocarbonoclastic bacteria associated with mat samples colonized soil more readily than seawater. The predominant oil degrading bacterium in seawater batches was the autochthonous seawater species Marinobacter hydrocarbonoclasticus. The main oil degraders in the inoculated soil samples, on the other hand, were a mixture of the autochthonous mat and desert soil bacteria; Xanthobacter tagetidis, Pseudomonas geniculata, Olivibacter ginsengisoli and others. More bacterial diversity prevailed in seawater during continuous than batch bioremediation. Out of seven hydrocarbonoclastic bacterial species isolated from those cultures, only one, Mycobacterium chlorophenolicum, was of mat origin. This result too confirms that most of the autochthonous mat bacteria failed to colonize seawater. Also culture-independent analysis of seawater from continuous cultures revealed high-bacterial diversity. Many of the bacteria belonged to the Alphaproteobacteria, Flavobacteria and Gammaproteobacteria, and were hydrocarbonoclastic. Optimal biostimulation practices for continuous culture bioremediation of seawater via mat bioaugmentation were adding the highest possible oil concentration as one lot in the beginning of bioremediation, addition of vitamins, and slowing down the seawater flow rate. PMID:26751253

  19. Modifying landing mat material properties may decrease peak contact forces but increase forefoot forces in gymnastics landings.

    Science.gov (United States)

    Mills, Chris; Yeadon, Maurice R; Pain, Matthew T G

    2010-09-01

    This study investigated how changes in the material properties of a landing mat could minimise ground reaction forces (GRF) and internal loading on a gymnast during landing. A multi-layer model of a gymnastics competition landing mat and a subject-specific seven-link wobbling mass model of a gymnast were developed to address this aim. Landing mat properties (stiffness and damping) were optimised using a Simplex algorithm to minimise GRF and internal loading. The optimisation of the landing mat parameters was characterised by minimal changes to the mat's stiffness (<0.5%) but increased damping (272%) compared to the competition landing mat. Changes to the landing mat resulted in reduced peak vertical and horizontal GRF and reduced bone bending moments in the shank and thigh compared to a matching simulation. Peak bone bending moments within the thigh and shank were reduced by 6% from 321.5 Nm to 302.5Nm and GRF by 12% from 8626 N to 7552 N when compared to a matching simulation. The reduction in these forces may help to reduce the risk of bone fracture injury associated with a single landing and reduce the risk of a chronic injury such as a stress fracture. PMID:21162361

  20. Fabrication of Pamidronic Acid-Immobilized TiO2/Hydroxyapatite Composite Nanofiber Mats for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Yong-Suk Shin

    2013-01-01

    Full Text Available TiO2/hydroxyapatite (TiO2/HA composite nanofiber mats were fabricated using an electrospinning technique. Subsequently, pamidronic acid (PDA was immobilized on the surface of the TiO2/HA nanofiber mat to improve osseointegration. X-ray photoelectron microscopy and scanning electron microscopy (SEM were used to characterize the structure and morphology of the PDA-immobilized TiO2/HA composite nanofiber mat (TiO2/HA-P. The potential of TiO2/HA-P as a bone scaffold was assessed by examining the cell adhesion and proliferation of osteoblasts and osteoclasts. The adhesion and proliferation of osteoblasts on the TiO2/HA-P composite nanofiber mat were slightly higher than those on the TiO2/HA composite nanofiber mat, whereas the viability of osteoclasts on the TiO2/HA-P nanofiber mat was significantly suppressed. These results suggest that the TiO2/HA-P nanofiber mat has the potential for use as a therapeutic bone implant.

  1. Occurrence of Cryptosporidium spp. and Giardia spp. in a public water-treatment system, Paraná, Southern Brazil.

    Science.gov (United States)

    Almeida, Jonatas Campos; Martins, Felippe Danyel Cardoso; Ferreira Neto, José Maurício; Santos, Maíra Moreira Dos; Garcia, João Luis; Navarro, Italmar Teodorico; Kuroda, Emília Kiyomi; Freire, Roberta Lemos

    2015-01-01

    The purpose of this study was to investigate the occurrence of Cryptosporidium spp. and Giardia spp. in a public water-treatment system. Samples of raw and treated water were collected and concentrated using the membrane filtration technique. Direct Immunofluorescence Test was performed on the samples. DNA extraction using a commercial kit was performed and the DNA extracted was submitted to a nested-PCR reaction (n-PCR) and sequencing. In the immunofluorescence, 2/24 (8.33%) samples of raw water were positive for Giardia spp.. In n-PCR and sequencing, 2/24 (8.33%) samples of raw water were positive for Giardia spp., and 2/24 (8.33%) samples were positive for Cryptosporidium spp.. The sequencing showed Cryptosporidium parvum and Giardia duodenalis DNA. In raw water, there was moderate correlation among turbidity, color and Cryptosporidium spp. and between turbidity and Giardia spp.. The presence of these protozoans in the water indicates the need for monitoring for water-treatment companies. PMID:26291147

  2. Seasonal variation in evapotranspiration from mat rush grown in paddy field

    International Nuclear Information System (INIS)

    Evapotranspiration from mat rush (Juncus effusus L.) was observed using the Bowen ratio method based on heat balance in a commercial paddy field located on the Yatsushiro Plain (32° 33.9′N, 130° 38.4′E, 1 m above sea level). Observations were conducted from transplanting (December) to harvest (July) in 1999/2000 (2000 season) and 2000/2001 (2001 season). Seasonal variation of evapotranspiration (E) showed an increasing trend with air temperature and solar radiation. Average and total values of E during the entire growth period in the 2000 and 2001 seasons were 2.02, 2.16 mm day-1 and 491, 499 mm, respectively. Daily mean values of E were compared with the reference crop evapotranspiration (E0) and potential evaporation (EP). Seasonal variations of E/E0 showed an increasing trend from 0.46 to 1.00 during the growth of mat rush. Similarly, E/EP showed an increasing trend from 0.42 to 0.84 during the growth of mat rush. E/E0 and E/EP of mat rush could be expressed as a function of plant area index (PAI). Root mean square error (RMSE) of estimating E using the function was 0.5 mm day-1 on a 1-day scale, 0.2 mm day-1 on a 5-day scale and 0.1 mm day-1 on a 10-day scale. Variations in E/E0 and E/EP were conjectured to be also influenced by soil moisture, wind speed and saturation deficit as the result of change in transpiration from mat rush. However, it was difficult to explain the difference in E/E0 and E/EP that was found between 2000 and 2001 seasons, based only on the difference in environmental factors described above. It was suggested that the difference in the physiological activity of the mat rush, which was indicated by differences in stem color between 2000 and 2001 seasons, affected the E/E0 and E/EP. (author)

  3. Phylogenetic Evidence for the Existence of Novel Thermophilic Bacteria in Hot Spring Sulfur-Turf Microbial Mats in Japan

    OpenAIRE

    Yamamoto, Hiroyuki; Hiraishi, Akira; Kato, Kenji; Chiura, Hiroshi X.; Maki, Yonosuke; Shimizu, Akira

    1998-01-01

    So-called sulfur-turf microbial mats, which are macroscopic white filaments or bundles consisting of large sausage-shaped bacteria and elemental sulfur particles, occur in sulfide-containing hot springs in Japan. However, no thermophiles from sulfur-turf mats have yet been isolated as cultivable strains. This study was undertaken to determine the phylogenetic positions of the sausage-shaped bacteria in sulfur-turf mats by direct cloning and sequencing of 16S rRNA genes amplified from the bulk...

  4. Effects of algae-mat thickness on survival and growth of eelgrass (Zostera marina) seedlings

    DEFF Research Database (Denmark)

    Rasmussen, Jonas; Olesen, Birgit

    eelgrass even short periods of water column anoxia may have severe implications for growth and survival. In addition, excessive covering by macroalgal mats decrease the available light at leaf surface and may hamper the diffusive movement of oxygen, inorganic carbon and nutrients to and from the shoot thus......: Chaetomorpha linum and artificial macroalgae. The two types of mats were used to separate physical and metabolic effects of algal presence. During the growth period concentrations of oxygen and sulphide and their diurnal variations in the mats were measured using microelectrodes....

  5. Large red cyanobacterial mats (Spirulina subsalsa Oersted ex Gomont in the shallow sublittoral of the southern Baltic

    Directory of Open Access Journals (Sweden)

    Piotr Balazy

    2014-06-01

    Full Text Available We report the first observation of large red cyanobacterial mats in the southern Baltic Sea. The mats (up to 2.5 m in diameter were observed by SCUBA divers at 7.7 m depth on loamy sediments in the Gulf of Gdańsk in mid-November 2013. The main structure of the mat was formed by cyanobacteria Spirulina subsalsa Oersted ex Gomont; a number of other cyanobacteria, diatoms and nematode species were also present. After a few days in the laboratory, the red trichomes of S. subsalsa started to turn blue-green in colour, suggesting the strong chromatic acclimation abilities of this species.

  6. Incidence and inactivation of Listeria spp. on frozen shrimp

    Science.gov (United States)

    Foodborne illness outbreaks occasionally occur as a result of microbiologically contaminated crustaceans, including shrimp. Foodborne pathogens occasionally found on shrimp include Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Vibrios. In this study the microbiological qualit...

  7. An alternative bacteriological medium for the isolation of Aeromonas spp.

    Science.gov (United States)

    Jenkins, J.A.; Taylor, P.W.

    1995-01-01

    Two solid bacteriologic media were compared for cultivating Aeromonas spp. from piscine sources: the Rimler-Shotts (RS) medium and a starch-glutamate-ampicillin-penicillin-based medium (SGAP-10C) used for the recovery of Aeromonas spp. from water samples. The selective and differential capacities of the media were assessed March through October 1992 by recovery rate and phenotype of 99 isolates representing 15 genera of bacteria. Recovery frequency of Aeromonas spp. (n = 62) was similar at 97% on RS and 95% on SGAP-10C. The SGAP-10C medium proved to be more specific than RS toward Aeromonas species (P ≤ 0.005). Use of SGAP-10C at 24 C for 48 hr offers a better choice for the laboratory recovery of Aeromonas spp. from clinical fish specimens.

  8. Symbiotic relationship of Thiothrix spp. with an echinoderm

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R.L. [Westinghouse Savannah River Co., Aiken, SC (United States); De Ridder, C. [Univ. Libre de Bruxelles, Brussels (Belgium). Lab. de Biologie Marine

    1998-09-01

    Thiothrix-like bacteria have been reported as symbionts in invertebrates from sulfide-rich habitats. Isolation of these symbiotic Thiothrix-like bacteria has failed, and the organisms have not been previously identified with certainty. The genus Thiothrix was created for ensheathed filamentous bacteria that oxidize sulfide and deposit sulfur granules internally, attach to substrates, produce gliding gonidia, and form rosettes. Immunoassay procedures were used to investigate the symbiotic relationship of Thiothrix spp. in the intestinal cecum of the spatangoid species Echinocardium cordatum. Thiothrix spp. were identified in nodule samples from E. cordatum digestive tubes based on microscopic examination, enzyme-linked immunosorbent assay, and indirect immunofluorescence. Thiothrix spp. protein made up as much as 84% of the total protein content of the nodules. This is the first identification of Thiothrix spp. internally symbiotic with marine invertebrates.

  9. Physiology and immunology of mucosal barriers in catfish (Ictalurus spp.)

    Science.gov (United States)

    The mucosal barriers of catfish (Ictalurus spp.) constitute the first line of defense against pathogen invasion while simultaneously carrying out a diverse array of other critical physiological processes, including nutrient adsorption, osmoregulation, waste excretion, and environmental sensing. Catf...

  10. Identification of Yersinia spp. with the API 20E system.

    OpenAIRE

    Archer, J R; Schell, R F; Pennell, D R; Wick, P D

    1987-01-01

    The ability of the API 20E system to identify 105 clinical isolates of Yersinia spp. was compared with those of conventional biochemical tests at 28 and 37 degrees C. Elimination of the Voges-Proskauer test (recorded as a negative result) increased the percentage of correct identifications for Yersinia spp. from 66 to 93% when the API 20E strips were incubated at 28 degrees C.

  11. Prevalence of Demodex spp among alcohol-dependent patients

    OpenAIRE

    Mehmet Hanifi Kokacya; Ozlem Aycan Kaya; Umit Sertan Copoglu; Sibel Elmacioglu

    2016-01-01

    Purpose: Demodex folliculorum and Demodex brevis are common ectoparasites found in humans and live on the pilosebaceous glands and hair follicles especially on the facial region. Chronic alcohol consumption can weaken immune system and cause more severe infections. Demodex spp is assumed to be more common in alcohol-dependent patients due to partial suppression of immune system and lack of good self-care. The present study aims to investigate the prevalence of Demodex spp. ectoparasite in alc...

  12. Cefotaxime resistance and outcome of Klebsiella spp bloodstream infection.

    Science.gov (United States)

    Ortega, M; Marco, F; Soriano, A; Almela, M; Martínez, J A; López, J; Pitart, C; Mensa, J

    2011-12-01

    We attempt to describe the epidemiology and outcome associated with cefotaxime-resistant (CTX-R) Klebsiella spp bacteraemia. Klebsiella spp bloodstream infection episodes prospectively collected through a blood culture surveillance programme from January 1991 to December 2008 in a single institution were analysed. A total of 910 monomicrobial episodes of Klebsiella spp bacteraemia were identified during the study period. The most important sources were from urinary tract infection, unknown sources, billiary focus and catheter related infection. There were 112 (12%) CTX-R isolates. Out of 112 isolates, 98 were CTX-R by Extended-Spectrum β-Lactamase production. Shock on presentation and mortality were significantly more frequent in CTX-R than in CTX susceptible isolates. Inappropriate empirical therapy was received in 50 (45%) cases in the CTX-R Klebsiella spp group (13 cases of death, 26%). Predictive factors associated with CTX-R Klebsiella spp isolate were: previous β-lactam therapy (OR = 4.16), nosocomial acquired bacteraemia (OR = 1.93), solid organ trasplantation (OR = 2.09) and shock (OR = 1.90). Independent risk factors associated with mortality in Klebsiella spp bacteraemia were: age (OR = 1.03), liver cirrhosis (OR = 2.63), ultimately or rapidly fatal prognosis of underlying disease (OR = 2.44), shock (OR = 8.60), pneumonia (OR = 4.96) or intraabdominal (OR = 3.85) source of bacteraemia and CTX-R isolate (OR = 4.63). Klebsiella spp is an important cause of bloodstream infection. CTX-R isolates have been increasing since 2000. CTX-R is an independent factor associated with mortality in Klebsiella spp bacteraemia. PMID:21509474

  13. Isolation of Cronobacter spp. (Enterobacter sakazakii from artisanal mozzarella

    Directory of Open Access Journals (Sweden)

    Francesco Casalinuovo

    2014-02-01

    Full Text Available Cronobacter spp. (Enterobacter sakazakii is an opportunistic bacterial pathogen capable of causing disease and even fatalities in newborn infants within the first weeks of life if consumed as part of the diet. Premature and immunocompromised newborn infants are at particular risk. The microorganism has been isolated from a variety of foods including contaminated infant milk formula powder and milk powder substitute. The study aimed to evaluate the level of microbiological contamination in 47 samples of mozzarella cheese made with cow’s milk collected from artisan cheese producers in Southern Italy. Samples were collected from commercial sales points and underwent qualitative and quantitative microbiological analyses to test for the bacterial contaminants most commonly found in milk and cheese products. The 47 samples underwent qualitative and quantitative microbiological tests according to ISO UNI EN standards. Analyses focused on Staphylococcus aures, Salmonella spp., Listeria monocytogenes, Pseudomonas spp., E. coli, Yersinia spp., total coliforms and Cronobacter sakazakii. The ISO/TS 22964:2006 method was used to investigate possible contamination by C. sakazakii. Biochemical identification was carried out using an automated system for identification and susceptibility tests. None of the samples examined resulted positive for Salmonella spp. or Listeria spp. Only one sample resulted positive for Staphylococcus aureus. Pseudomonas spp. was isolated in 10 (21% of 47 samples. High levels of total coliforms were found in 10 of 47 samples. Cronobacter spp. (Enterobacter sakazakii was isolated in one sample. This is the first study to confirm isolation of C. sakazakii in artisan mozzarella cheese made from cow’s milk. The presence of C. sakazakii could be related to external contamination during the phases of production or to the use of contaminated milk. Since mozzarella is recommended in the diet of children and adults of all ages, this

  14. Laboratory diagnosis of Blastocystis spp. in diarrheic patients

    OpenAIRE

    Elghareeb, Azza S; Younis, Mohamed S; El Fakahany, Amany F; Nagaty, Ibrahim M; Nagib, Marwa M

    2015-01-01

    Background: Many laboratories currently diagnose Blastocystis spp. infections by looking for the presence of vacuolar forms in faeces and the amoeboid form in diarrheal stools. Objectives: To investigate the best direct method in diagnosis of Blastocystis spp. and to study different morphological forms of the parasite. Materials and Methods: The study was carried out on one thousand and two hundred diarrheic stool samples. All samples were examined using direct smear, iodine stained smear, fo...

  15. Protoanemonin content variation between Clematis spp.: leaf, stem and root.

    Science.gov (United States)

    Jin, Fangming; Narkowicz, Christian; Jacobson, Glenn A

    2013-02-01

    The content of protoanemonin, a known biologically active constituent of Clematis spp., was determined by GC-MS in the leaf, stem and root extracts of one Chinese species and four Australian Clematis taxa. The results showed that protoanemonin concentrations varied between different plants and that leaves contained higher concentrations than stems and roots. To our knowledge this is the first study to determine protoanemonin content variation in leaf, stem and root of Clematis spp. PMID:23513731

  16. Survival of Escherichia coli and Salmonella spp. in estuarine environments.

    OpenAIRE

    Rhodes, M W; Kator, H.

    1988-01-01

    Survival of Escherichia coli and Salmonella spp. in estuarine waters was compared over a variety of seasonal temperatures during in situ exposure in diffusion chambers. Sublethal stress was measured by both selective-versus-resuscitative enumeration procedures and an electrochemical detection method. E. coli and Salmonella spp. test suspensions, prepared to minimize sublethal injury, were exposed in a shallow tidal creek and at a site 7.1 km further downriver. Bacterial die-off and sublethal ...

  17. A monograph on amylases from Bacillus spp.

    OpenAIRE

    M. K. Sarath Josh; S. Sreedevi; Prakasan Priji; K. N. Unni; S Sajith; S.Pradeep; V. N. Jisha; R. B. Smitha; Sailas Benjamin

    2013-01-01

    Owing to the production of alpha, beta and gamma amylase subtypes; starch degrading microbes, especially bacteria have an invincible role in the food, fermentation, textile and paper industries. Of them, α-amylases from Bacillus spp. have contributed tremendous advancements in bio-industry, especially in starch, detergent and pharmaceutical arena. Though general reviews are seen in literature on amylases, no focused review is available yet solely on α-amylases produced by Bacillus spp. Hence...

  18. Molecular Characterization of Non-flowering Perennial Sorghum spp. Hybrids

    OpenAIRE

    Jessup, R. W.; Whitmire, D. K.; Farrow, Z. L.; Burson, B. L.

    2011-01-01

    Aims: The goal of this study was to characterize recently identified, non-flowering, putative tetraploid Sorghum spp. hybrids utilizing bulked segregant analysis with SSRs and compare them to S. bicolor, S. halepense, and triploid putative Sorghum spp. hybrids. Confirmed species hybrids between S. bicolor and S. halepense would provide resources for investigating risks of invasiveness and transgene escape alongside potential for identifying novel perennial Sorghum feedstocks of value. Study d...

  19. Severe spp. infections: new insights into natural immunity

    OpenAIRE

    van der Meer, Jos W.M.; van de Veerdonk, Frank L.; Joosten, Leo A. B.; Kullberg, Bart-Jan; Mihai G Netea

    2010-01-01

    International audience Invasive infections caused by spp. are associated with high mortality. Colonization by spp. and the capacity of the host to recognize them as potential pathogens are essential steps in the development of these infections. The major pathogen-associated molecular patterns of are mannoproteins, glucans and chitins, which are recognized by C-type lectin pattern recognition receptors such as the mannose receptor, dectin-1 and dectin-2. By the secretion of proteases and to...

  20. Management of Root-Nematode (Meloidogyne SPP)

    International Nuclear Information System (INIS)

    Greenhouse and field experiments were undertaken to determine the possibility of using soil amendments with different C:N levels or applied at different rates and times in the control of root-knot nematodes (Meloidogyne spp.)in tomato c.v Cal J.A naturally infested field was used while artificial inoculation was done in the greenhouse. Root galling was rated on a scale of 0-10, nematode population was estimated by counting second stage juveniles extracted from 200 cm3 soil and fruit yields were recorded at the end of the season. Nematode population densities and galling indices were significantly (P< or=0.05) lower in amended soils compared to the control. Application of the amendments also resulted in significant (P< or=0.05) increase in yields. Chicken manure, compost manure, neem products and pig manure were were the most effective amendments. Fresh chicken manure had a more suppressive effect on nematode than when the manure was decomposed within or outside a nematode infested field. A general decrease in juvenile populations and galling was observed with increase of organic amendments applied

  1. Brachiaria spp. poisoning of ruminants in Brazil

    Directory of Open Access Journals (Sweden)

    B. Riet-Correa

    2011-03-01

    Full Text Available Brachiaria species are the most important grasses for cattle production in Brazil. However, a limiting factor for the use of Brachiaria spp. is their toxicity. Most outbreaks of hepatogenous photosensitization are caused by B. decumbens; however B. brizantha, B. humidicola and B. ruziziensis can also cause poisoning. The poisoning affects cattle, sheep, goats and buffalo. Sheep are more susceptible than other animal species and the young are more susceptible than adults. There are differences in susceptibility among animals of the same species and it has been suggested that this resistance is genetic. Also has been suggested that buffalo and probably some sheep are resilient, i.e. when poisoned these animals have histologic lesions and high GGT serum concentrations, but do not show clinical signs. In general, saponin concentrations are higher in growing plants, but outbreaks occur all over the year, probably due to unexplained rise in saponin concentration in the plant. A clinical syndrome of progressive weight loss and death, without photosensitization, has been reported in cattle poisoned by B. decumbens. Main preventive measures are based on the selection of resistant or resilient animals and on the development of Brachiaria species or varieties with low saponin concentration.

  2. Rooting cuttings of yam (Dioscorea spp.

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Rocha e Silva

    2014-12-01

    Full Text Available The culture of yams (Dioscorea spp. has great importance for the entire Brazilian population, mainly in the Northeast, either by its nutritional or commercial value. This work aimed to study a new method of seedling production of yams by stem cuttings collected from plants with age of 120 days. The experiment was carried out in the CECA/UFAL, in a green house with intermittent fogging, in a fully randomized block design with a factorial 3 × 2 × 2, 12 treatments and 4 replications. Three factors were evaluated: height of the cuttings collection in plant (top, center and bottom, position of the cuttings on the branch (proximal and distal and concentration of Indolebutyric acid (IBA applied (0 and 1 mg/L. The cuttings were planted in plastic trays of 32 cells, containing commercial Bioplant ® substrate. After 30 days, the presence, the number and length of roots was acessed. All variables were subjected to analysis of variance and averages were compared by Tukey test. The results obtained in this study showed that the use of IBA (1 g/L did not influence the rooting process. Cuttings collected in the basal third of the plants in the proximal part of the branches, independent of the concentration of IBA, presented the best results for the percentage of rooting, root number and length of roots per stake.

  3. Sylvatic Trichinella spp. infection in Finland.

    Science.gov (United States)

    Airas, Niina; Saari, Seppo; Mikkonen, Taina; Virtala, Anna-Maija; Pellikka, Jani; Oksanen, Antti; Isomursu, Marja; Kilpelä, Seija-Sisko; Lim, Chae W; Sukura, Antti

    2010-02-01

    Although human infections caused by Trichinella sp. have not been reported in Finland for several decades and Trichinella sp. infection in pork has become virtually extinct in the last decade, sylvatic Trichinella spp. infection is still highly prevalent in Finland. Muscle digestion of 2,483 carnivorous wild animals from 9 host species during 1999-2005 showed 617 positive animals (24.8%). Molecular identification from 328 larval isolates revealed 4 different endemic Trichinella species, i.e., T. nativa, T. spiralis, T. britovi, and T. pseudospiralis. Seven percent of the infected animals carried mixed infections. Trichinella nativa was the most common species (74%), but T. spiralis was identified in 12%, T. britovi in 6%, and T. pseudospiralis in 1% of the animals. Host species showed different sample prevalence and Trichinella species distribution. Geographical distribution also varied, with the southern part of the country having significantly higher percentages than the northern part. Infection density was dependent on both the infecting Trichinella species and the host species. Trichinella spiralis was discovered in areas with no known domestic infection cases, indicating that it can also occur in the sylvatic cycle. Raccoon dogs and red foxes are the most important reservoir animals for T. spiralis , as well as for the sylvatic Trichinella species in Finland. PMID:19731970

  4. SPP Beamline Design and Beam Dynamics

    CERN Document Server

    Turemen, G; Yasatekin, B; Yildiz, V; Celik, M; Alacakir, A; Unel, G; Mete, O

    2014-01-01

    The Radio Frequency Quadrupole of SANAEM Project Prometheus will be a demonstration and educational machine which will accelerate protons from 20 keV to 1.5 MeV. The project is funded by Turkish Atomic Energy Authority and it will be located at Saraykoy Nuclear Research and Training Center in Ankara. The SPP beamline consists of a multi-cusp H+ ion source, a Low Energy Beam Transport line and a four-vane RFQ operating at 352.2 MHz. The design studies for the multi-cusp ion source (RF or DC) were performed with IBSimu and SIMION software packages. The source has already been produced and currently undergoes extensive testing. There is also a preliminary design for the solenoid based LEBT, POISSON and PATH were used in parallel for the preliminary design. Two solenoid magnets are produced following this design. The RFQ design was made using LIDOS.RFQ.Designer and it was crosschecked with a home-grown software package, DEMIRCI. The initial beam dynamics studies have been performed with both LIDOS and TOUTATIS. T...

  5. The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats

    DEFF Research Database (Denmark)

    Teske, Andreas; de Beer, Dirk; McKay, Luke J; Tivey, Margaret K; Biddle, Jennifer F; Hoer, Daniel; Lloyd, Karen G; Lever, Mark A; Røy, Hans; Albert, Daniel B; Mendlovitz, Howard P; MacGregor, Barbara J

    2016-01-01

    The hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and...... selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediments show their steep geochemical and thermal gradients at millimeter-scale vertical resolution. Mapping these...... hydrothermal features and sampling locations within the southern Guaymas Basin suggest linkages to underlying shallow sills and heat flow gradients. Recognizing the inherent spatial limitations of much current Guaymas Basin sampling calls for comprehensive surveys of the wider spreading region....

  6. Nanostructured Polylactic Acid/Candeia Essential Oil Mats Obtained by Electrospinning

    Directory of Open Access Journals (Sweden)

    Cláudia L. S. de Oliveira Mori

    2015-01-01

    Full Text Available This work aims to evaluate the effect of inclusion of different contents of candeia (Eremanthus erythropappus essential oil (whose alpha-bisabolol is the main terpene on the properties of polylactic acid (PLA nanostructured mats and their relationship with fiber morphology and structure. The interaction occurring between the PLA and the candeia essential oil was confirmed by thermal and microscopy analysis. Addition of candeia essential oil increased nanofiber diameter and decreased the glass transition and melting temperatures of the nanofibers, suggesting lower energy input for processing. Scanning electron microscopy (SEM images provided evidence of a homogeneous structure for the nanostructured mats. X-ray diffraction did not show differences in the crystallization of the nanofibers. This ongoing research confirms the possibility of incorporation of candeia essential oil in the production of nanofibers that will be studied for multipurpose applications.

  7. MatSeis developer's guide:version 1.0.

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, Lane Christopher; Young, Christopher John

    2007-05-01

    This guide is intended to enable researchers working with seismic data, but lacking backgrounds in computer science and programming, to develop seismic algorithms using the MATLAB-based MatSeis software. Specifically, it presents a series of step-by-step instructions to write four specific functions of increasing complexity, while simultaneously explaining the notation, syntax, and general program design of the functions being written. The ultimate goal is that that the user can use this guide as a jumping off point from which he or she can write new functions that are compatible with and expand the capabilities of the current MatSeis software that has been developed as part of the Ground-based Nuclear Explosion Monitoring Research and Engineering (GNEMRE) program at Sandia National Laboratories.

  8. Molecular Ecology of Hypersaline Microbial Mats: Current Insights and New Directions

    Directory of Open Access Journals (Sweden)

    Hon Lun Wong

    2016-01-01

    Full Text Available Microbial mats are unique geobiological ecosystems that form as a result of complex communities of microorganisms interacting with each other and their physical environment. Both the microorganisms present and the network of metabolic interactions govern ecosystem function therein. These systems are often found in a range of extreme environments, and those found in elevated salinity have been particularly well studied. The purpose of this review is to briefly describe the molecular ecology of select model hypersaline mat systems (Guerrero Negro, Shark Bay, S’Avall, and Kiritimati Atoll, and any potentially modulating effects caused by salinity to community structure. In addition, we discuss several emerging issues in the field (linking function to newly discovered phyla and microbial dark matter, which illustrate the changing paradigm that is seen as technology has rapidly advanced in the study of these extreme and evolutionally significant ecosystems.

  9. Mise au point de deux nouveaux matériaux à base de cobalt

    OpenAIRE

    CEA

    2014-01-01

    Des chercheurs du CEA, du CNRS, du Collège de France et de l’Université de Grenoble ont mis au point deux nouveaux matériaux à base de cobalt capables de remplacer le platine, métal rare et cher, dans la production d’hydrogène à partir d’eau (électrolyse). L’un peut fonctionner en solution aqueuse de pH neutre. Le second constitue le premier matériau catalytique « commutable » et sans métaux nobles jamais créé capable d’intervenir dans les deux réactions chimiques essentielles à l’électrolys...

  10. Premixed combustion of coke oven gas in a metallic fibre mat

    Energy Technology Data Exchange (ETDEWEB)

    Cho, K.W.; Han, K.; Lee, Y.K.; Noh, D.-S.; Yoon, H.M.; Riu, K.-J.; Lee, K.-H. [Research Institute of Industrial Science and Technology, Pohang (Republic of Korea). Energy Research Team

    2001-05-01

    Combustion characteristics of liquefied petroleum gas (LPG) and coke oven gas (COG) in a metallic fibre mat were investigated experimentally to examine the effect of fuel change on surface combustion performance. It was found that the upper limit of surface loads representing the radiant mode is increased in the case of COG combustion. Mat temperatures were slightly lowered for COG combustion at low surface loads. The surface load showing the maximum surface temperature was shifted to a higher one for COG combustion. It was concluded that the range of surface loads for radiant mode combustion and the surface load for the peak surface temperature are mainly dependent upon the flame speed of the fuel used. Short communication. 13 refs., 3 figs., 1 tab.

  11. Transparent conducting film: Effect of mechanical stretching to optical and electrical properties of carbon nanotube mat

    Indian Academy of Sciences (India)

    Tsuyoshi Saotome; Hansang Kim; David Lashmore; H Thomas Hahn

    2011-07-01

    We describe in this paper a transparent conducting film (TCF). It is a fibrous layer of multiwalled carbon nanotubes (MWNTs), labeled a dilute CNT mat, that was prepared and unidirectionally stretched to improve both the optical and electrical properties. After stretching by 80% strain, transmittance at 550 nm wavelength was improved by 37% and sheet resistance was reduced to 71% of the original value. The improvement of the transmittance can be explained by increased area of the CNT mat after stretch, and the reduced sheet resistance can be explained by increased density of the CNT alignment in lateral direction due to contraction. Based on the microscopic observation before and after stretch, models to describe the phenomena are proposed. By further expanding on this method, it may be possible to obtain a transparent conducting carbon nanotube film which is crack-resistant for solar cell applications.

  12. Rhéologie des pâtes et des matériaux granulaires

    OpenAIRE

    LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES - LCPC

    2006-01-01

    Recueil de huit articles synthétiques, ce rapport constitue un bilan de recherches coordonnées des laboratoires des ponts et chaussées, au cours des années 2002-2005, sur les matériaux du génie civil, dont la rhéologie est mal comprise, susceptibles de comportements " solides " ou " liquides " : les pâtes (comme les ciments frais) et les assemblages granulaires (sols pulvérulents, granulats, poudres), éventuellement liés (cas des matériaux de chaussées).Y sont présentés les récents progrès da...

  13. Rhéologie des pâtes et des matériaux granulaires

    OpenAIRE

    LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES - LCPC

    2006-01-01

    Recueil de huit articles synthétiques, ce rapport constitue un bilan de recherches coordonnées des laboratoires des ponts et chaussées, au cours des années 2002-2005, sur les matériaux du génie civil, dont la rhéologie est mal comprise, susceptibles de comportements "solides" ou " liquides" : les pâtes (comme les ciments frais) et les assemblages granulaires (sols pulvérulents, granulats, poudres), éventuellement liés (cas des matériaux de chaussées). Y sont présentés les récents progrès dans...

  14. Evaluation of arboviruses of public health interest in free-living non-human primates (Alouatta spp., Callithrix spp., Sapajus spp. in Brazil

    Directory of Open Access Journals (Sweden)

    Tatiana Carneiro da Rocha

    2015-04-01

    Full Text Available INTRODUCTION: The aim of the present study was to evaluate the presence of arboviruses from the Flavivirus genus in asymptomatic free-living non-human primates (NHPs living in close contact with humans and vectors in the States of Paraná and Mato Grosso do Sul, Brazil. METHODS: NHP sera samples (total n = 80, Alouatta spp. n = 07, Callithrix spp. n = 29 and Sapajus spp. n = 44 were screened for the presence of viral genomes using reverse transcription polymerase chain reaction and 10% polyacrylamide gel electrophoresis techniques. RESULTS: All of the samples were negative for the Flavivirus genome following the 10% polyacrylamide gel electrophoresis analysis. CONCLUSIONS: These negative results indicate that the analyzed animals were not infected with arboviruses from the Flavivirus genus and did not represent a risk for viral transmission through vectors during the period in which the samples were collected.

  15. Response of mat conditions and flakeboard properties to steam- injection variables

    OpenAIRE

    Johnson, Stephen E.

    1990-01-01

    Mat conditions of temperature and gas pressure were measured in three locations for one conventional and four steam-injection press schedules used in the laboratory scale manufacture of aspen (Populus grandidentata and Populus tremuloides) flakeboard. Two resins, phenol formaldehyde and polymeric MDI, were used. Steam-injection press schedules varied from low steam input to high steam input by adjusting steam pressure, steam time, and the density range for steam-inject...

  16. Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

    OpenAIRE

    Yongfang Qian; Zhen Zhang; Laijiu Zheng; Ruoyuan Song; Yuping Zhao

    2014-01-01

    Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θ of 21° and 23.5° gradually decreased with the percentage of chit...

  17. The MATS experiments - mesoscale atmospheric transport studies at the Savannah River Site

    International Nuclear Information System (INIS)

    An overview of the Mesoscale Atmospheric Transport Studies (MATS) program is presented. MATS was an experimental program to create a data base for short-term atmospheric releases to study mesoscale atmospheric dispersion over gently rolling terrain at the Savannah River Site (SRS). Thirty-one experiments were performed over a 3-year period under daytime convective conditions using 15-minute releases of sulfur hexafluoride (SF6) tracer. Dispersion was typically measured along an arc of stationary samplers approximately 30 km downwind. Four nighttime experiments were performed with SF6 releases, and sampling was carried on for a few hours with a mobile sampling laboratory. The mobile laboratory repeatedly traversed the plume while recording tracer concentration, time, and location. Supporting meteorological data for the MATS experiments included wind and temperature measurements from an integrated meteorological tower network and computer system. The tower network consists of eight instrumented, 61-m towers located near each of SRS's major facilities and a 304-m television tower located about 16 km WNW from the SRS administrative area. Low-level soundings obtained from on-site launches of mini-rawinsondes and Airsondes provided additional date on the vertical structure of the boundary layer for 11 of the experiments. Soundings were also obtained for Athens, GA., and Charleston, SC, from the National Climatic Data Center. The MATS data set is available for use by diffusion researchers and modelers. Two experiments were examined in detail and compared with predictions from a simple Gaussian model to help demonstrate the usefulness of the data. These cases show that the downwind locations of tracer material were predicted adequately if uniform winds at release level were assumed but that the magnitude of the concentration was overpredicted by factors of 2.5 and 10. 21 refs., 14 figs., 4 tabs

  18. Diversity of Heterotrophic Nitrogen Fixation Genes in a Marine Cyanobacterial Mat

    OpenAIRE

    J. P. Zehr; Mellon, M.; Braun, S.; Litaker, W; Steppe, T.; Paerl, H W

    1995-01-01

    The diversity of nitrogenase genes in a marine cyanobacterial mat was investigated through amplification of a fragment of nifH, which encodes the Fe protein of the nitrogenase complex. The amplified nifH products were characterized by DNA sequencing and were compared with the sequences of nitrogenase genes from cultivated organisms. Phylogenetic analysis showed that similar organisms clustered together, with the exception that anaerobic bacteria clustered together, even though they represente...

  19. Summer season variability of dissolved oxygen concentration in Antarctic lakes rich in cyanobaterial mats

    OpenAIRE

    Váczi Peter; Barták Miloš

    2011-01-01

    Since 2007, limnological investigation of terrestrial lakes has been carried out at James Ross Island, Antarctica. The lakes in scope differ in their size, origin, geomorphological and hydrological characteristics. In several selected lakes, dissolved oxygen is measured repeatedly each summer season in order to quantify lake- and weather-related differences. For this study, typical reresentatives of (i) coastal shalow lakes, and (ii) high-altitude lakes with cyanobacterial mats were chosen. W...

  20. Multiarray on a test strip (MATS): rapid multiplex immunodetection of priority potato pathogens.

    Science.gov (United States)

    Safenkova, Irina V; Pankratova, Galina K; Zaitsev, Ilya A; Varitsev, Yuri A; Vengerov, Yuri Y; Zherdev, Anatoly V; Dzantiev, Boris B

    2016-09-01

    Multiarray on a test strip (MATS) was developed for the detection of eight important potato pathogens. The proposed assay combines the rapidity of immunochromatography with the high throughput of array techniques. The test zone of the immunochromatographic strip comprises ordered rows of spots containing antibodies specific for different potato pathogens. The assay benefits from the simplicity of immunochromatography; colored immune complexes form at the corresponding spots within the test zone. The presence and intensity of the coloration are used for identification of the target pathogens. The MATS was applied to the simultaneous detection of eight priority potato pathogens, characterized by the following limits of detection: 1 ng/mL for potato virus X and the ordinary type of potato virus Y, 10 ng/mL for potato virus M, 20 ng/mL for potato leaf roll virus, 40 ng/mL for necrotic-type potato virus Y, 100 ng/mL for potato virus S, 300 ng/mL for potato virus A, and 10(4) cells/mL for Clavibacter michiganensis subsp. sepedonicus. Analysis time was 15 min. The observed sensitivity of the MATS was comparable to the traditional enzyme-linked immunosorbent assay. The developed technique was tested on potato leaf extracts, and its efficiency for on-site control of the pathogens was confirmed in 100 % by commercial LFIA test strips. Graphical abstract Location of binding zones in the developed multiarray on a test strip (MATS) for simultaneous detection of eight pathogens. PMID:27007732

  1. Fermentation and Sulfur Reduction in the Mat-Building Cyanobacterium Microcoleus chthonoplastes

    OpenAIRE

    Moezelaar, R.; Bijvank, S. M.; Stal, L.J.

    1996-01-01

    The mat-building cyanobacterium Microcoleus chthonoplastes carried out a mixed-acid fermentation when incubated under anoxic conditions in the dark. Endogenous storage carbohydrate was fermented to acetate, ethanol, formate, lactate, H(inf2), and CO(inf2). Cells with a low glycogen content (about 0.3 (mu)mol of glucose per mg of protein) produced acetate and ethanol in equimolar amounts. In addition to glycogen, part of the osmoprotectant, glucosyl-glycerol, was degraded. The glucose componen...

  2. Microbial mats in Antarctica as models for the search of life on the Jovian moon Europa

    International Nuclear Information System (INIS)

    The possibility of sulfur patches on the Jovian satellite Europa being of biogenic origin is discussed. The presence of microbial mats and the accumulation of sulfur on the surface of some Antarctic subglacial lakes are correlated with the sulfur traces found on Europa by means of microbiological processes. Special attention has been paid to the influence of temperature and radiation on the icy surface of this Jovian satellite. An optimum penetration depth to look for biomarkers is proposed based on biogeochemical parameters. (author)

  3. Glass Fiber Reinforced Polymer Bars as the Top Mat Reinforcement for Bridge Decks

    OpenAIRE

    DeFreese, James Michael

    2001-01-01

    The primary objective of this research was to experimentally investigate material and bond properties of three different types of fiber reinforced polymer (FRP) bars, and determine their effect on the design of a bridge deck using FRP bars as the top mat of reinforcement. The properties evaluated include the tensile strength, modulus of elasticity, bond behavior, and maximum bond stress. The experimental program included 47 tensile tests and 42 beam end bond tests performed with FRP bars. ...

  4. Glass fiber reinforced polymer bars as top mat reinforcement for bridge decks

    OpenAIRE

    J.M. DeFreese; Roberts-Wollmann, Carin L.

    2002-01-01

    The objectives of this research were to characterize the material and bond properties of three commercially available GFRP (glass fiber reinforced polymer) reinforcing bars, and evaluate the effects of the material properties and the current ACI design recommendations (ACI 2001) on the design of a bridge deck with GFRP as top mat reinforcement. The tensile properties evaluated were ultimate tensile strength, tensile modulus of elasticity and ultimate rupture strain. Ultimate bond stress and l...

  5. Mat på arbetet dygnet runt? Arbete – Tid – Måltid

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Lagnevik, Magnus; Lindén, Anne-Lisa;

    nutritionister, som sociologer och företagsekonomer medverkar. I september 2008 hölls en workshop med utgångspunkt i rapporten ”Mat på arbetet dygnet runt”. Under workshopen deltog olika aktörer från båda sidor av Öresund, och denna slutrapport innehåller utöver en kunskapsöversikt och en jämförelse mellan...

  6. TRIGA-SPEC: the prototype of MATS and LaSpec

    Science.gov (United States)

    Kaufmann, S.; Beyer, T.; Blaum, K.; Block, M.; Düllmann, Ch E.; Eberhardt, K.; Eibach, M.; Geppert, C.; Gorges, C.; Grund, J.; Hammen, M.; Krämer, J.; Nagy, Sz; Nörtershäuser, W.; Renisch, D.; Schneider, F.; Wendt, K.

    2015-04-01

    Investigation of short-lived nuclei is a challenging task that MATS and LaSpec will handle at the low energy branch of Super-FRS at FAIR. The groundwork for those experiments is laid-out already today at the TRIGA-SPEC facility as a powerful development platform located at the research reactor TRIGA Mainz. The latest status, new developments and first results of commissioning runs are presented here.

  7. Development of multiplex real-time PCR assay for the detection of Brucella spp., Leptospira spp. and Campylobacter foetus

    Directory of Open Access Journals (Sweden)

    Abdelfattah M. Selim

    2014-12-01

    Full Text Available Abortion among dairy cattle is one of the major causes of economic losses in the livestock industry. This study describes a 1-step multiplex real-time polymerase chain reaction (PCR to detect Brucella spp., Leptospira spp. and Campylobacter foetus, these are significant bacteria commonly implicated in bovine abortion. ß-actin was added to the same PCR reaction as an internal control to detect any extraction failure or PCR inhibition. The detection limit of multiplex real-time PCR using purified DNA from cultured organisms was set to 5 fg for Leptospira spp. and C. foetus and to 50 fg for Brucella spp. The multiplex real-time PCR did not produce any non-specific amplification when tested with different strains of the 3 pathogens. This multiplex real-time PCR provides a valuable tool for diagnosis, simultaneous and rapid detection for the 3 pathogens causing abortion in bovine.

  8. Tracking the Effect of Algal Mats on Coral Bleaching Using Remote Sensing

    Science.gov (United States)

    El-Askary, H. M.; Johnson, S. H.; Idris, N.; Qurban, M. A. B.

    2014-12-01

    Benthic habitats rely on relatively stable environmental conditions for survival. The introduction of algal mats into an ecosystem can have a notable effect on the livelihood of organisms such as coral reefs by causing changes in the biogeochemistry of the surrounding water. Increasing levels of acidity and new competition for sunlight caused by congregations of cyanobacteria essentially starve coral reefs of natural resources. These changes are particularly prevalent in waters near quickly developing population centers, such as the ecologically diverse Arabian Gulf. While ground-truthing studies to determine the extensiveness of coral death proves useful on a microcosmic level, new ventures in remote sensing research allow scientists to utilize satellite data to track these changes on a broader scale. Satellite images acquired from Landsat 5, 1987, Landsat 7, 2000, and Landsat 8, 2013 along with higher resolution IKONOS data are digitally analyzed in order to create spectral libraries for relevant benthic types, which in turn can be used to perform supervised classifications and change detection analyses over a larger area. The supervised classifications performed over the three scenes show five significant marine-related classes, namely coral, mangroves, macro-algae, and seagrass, in different degrees of abundance, yet here we focus only on the algal mats impact on corals bleaching. The change detection analysis is introduced to study see the degree of algal mats impact on coral bleaching over the course of time with possible connection to the local meteorology and current climate scenarios.

  9. A class of Matérn-like covariance functions for smooth processes on a sphere

    KAUST Repository

    Jeong, Jaehong

    2015-02-01

    © 2014 Elsevier Ltd. There have been noticeable advancements in developing parametric covariance models for spatial and spatio-temporal data with various applications to environmental problems. However, literature on covariance models for processes defined on the surface of a sphere with great circle distance as a distance metric is still sparse, due to its mathematical difficulties. It is known that the popular Matérn covariance function, with smoothness parameter greater than 0.5, is not valid for processes on the surface of a sphere with great circle distance. We introduce an approach to produce Matérn-like covariance functions for smooth processes on the surface of a sphere that are valid with great circle distance. The resulting model is isotropic and positive definite on the surface of a sphere with great circle distance, with a natural extension for nonstationarity case. We present extensive numerical comparisons of our model, with a Matérn covariance model using great circle distance as well as chordal distance. We apply our new covariance model class to sea level pressure data, known to be smooth compared to other climate variables, from the CMIP5 climate model outputs.

  10. The effects of pilates mat exercise on the balance ability of elderly females.

    Science.gov (United States)

    Hyun, Ju; Hwangbo, Kak; Lee, Chae-Woo

    2014-02-01

    [Purpose] The purpose of this study was to examine the effects of Pilates exercise on a mat and balance exercise on an unstable base of support for trunk stability on the balance ability of elderly females. [Subjects and Methods] Forty elderly women aged 65 or older were equally assigned to a Pilates mat exercise (PME) group and an unstable support surface exercise (USSE) group. They conducted exercise three times per week for 12 weeks for 40 minutes each time. In order to examine balance, sway length and the speed of the center of foot pressure were measured for one minute, and in order to examine dynamic balance, the Timed Up and Go (TUG) test was conducted. [Results] After the intervention, sway length, sway speed, and TUG significantly decreased in both groups. A comparison of sway speed after the intervention between the two groups revealed that the PME group showed larger decreases than the USSE group. [Conclusion] PME and USSE elicited significant effects on the static and dynamic balance of elderly female subjects, suggesting that those exercises are effective at enhancing the balance ability of this group of subjects. However, the Pilates mat exercise is regarded as being safer than exercise on an unstable base of support. PMID:24648651

  11. Incorporation of Vanadium Oxide in Silica Nanofiber Mats via Electrospinning and Sol-Gel Synthesis

    Directory of Open Access Journals (Sweden)

    Jeanne E. Panels

    2006-01-01

    Full Text Available Submicron scale vanadia/silica hybrid nanofiber mats have been produced by electrospinning silica sol-gel precursor containing vanadium oxytriisopropoxide (VOTIP, followed by calcinations at high temperature. The properties of the resulting inorganic hybrid nanofiber mats are compared to those of electrospun pure silica nanofibers. SEM images show fibers are submicron in diameter and their morphology is maintained after calcination. Physisorption experiments reveal that silica nanofiber mats have a high specific surface area of 63 m2/g. FT-IR spectra exhibit Si—O vibrations and indicate the presence of V2O5 in the fibers. XPS studies reveal that the ratio of Si to O is close to 0.5 on the surface of fibers and the amount of vanadium on the surface of fibers increases with calcination. XRD diffraction patterns show that silica nanofibers are amorphous and orthorhombic V2O5 crystals have formed after calcination. EFTEM images demonstrate the growth of crystals on the surface of fibers containing vanadium after calcination. SEM images of fibers with high-vanadium content (50 mol% V: Si show that vanadia crystals are mostly aligned along the fiber axis. XPS shows an increase in vanadium contents at the surface, and XRD patterns exhibit an increase in the degree of crystallinity. A coaxial electrospinning scheme has successfully been employed to selectively place V2O5 in the skin layer.

  12. Multibeam Sonar Mapping and Modeling of a Submerged Bryophyte Mat in Crater Lake, Oregon

    Science.gov (United States)

    Dartnell, Peter; Collier, Robert; Buktenica, Mark; Jessup, Steven; Girdner, Scott; Triezenberg, Peter

    2008-01-01

    Traditionally, multibeam data have been used to map sea floor or lake floor morphology as well as the distribution of surficial facies in order to characterize the geologic component of benthic habitats. In addition to using multibeam data for geologic studies, we want to determine if these data can also be used directly to map the distribution of biota. Multibeam bathymetry and acoustic backscatter data collected in Crater Lake, Oregon, in 2000 are used to map the distribution of a deep-water bryophyte mat, which will be extremely useful for understanding the overall ecology of the lake. To map the bryophyte's distribution, depth range, acoustic backscatter intensity, and derived bathymetric index grids are used as inputs into a hierarchical decision-tree classification model. Observations of the bryophyte mat from over 23 line kilometers of lake-floor video collected in the summer of 2006 are used as controls for the model. The resulting map matches well with ground-truth information and shows that the bryophyte mat covers most of the platform surrounding Wizard Island as well as on outcrops around the caldera wall.

  13. Superhydrophobic, Hybrid, Electrospun Cellulose Acetate Nanofibrous Mats for Oil/Water Separation by Tailored Surface Modification.

    Science.gov (United States)

    Arslan, Osman; Aytac, Zeynep; Uyar, Tamer

    2016-08-01

    Electrospun cellulose acetate nanofibers (CA-NF) have been modified with perfluoro alkoxysilanes (FS/CA-NF) for tailoring their chemical and physical features aiming oil-water separation purposes. Strikingly, hybrid FS/CA-NF showed that perfluoro groups are rigidly positioned on the outer surface of the nanofibers providing superhydrophobic characteristic with a water contact angle of ∼155°. Detailed analysis showed that hydrolysis/condensation reactions led to the modification of the acetylated β(1 → 4) linked d-glucose chains of CA transforming it into a superhydrophobic nanofibrous mat. Analytical data have revealed that CA-NF surfaces can be selectively controlled for fabricating the durable, robust and water resistant hybrid electrospun nanofibrous mat. The -OH groups available on the CA structure allowed the basic sol-gel reactions started by the reactive FS hybrid precursor system which can be monitored by spectroscopic analysis. Since alkoxysilane groups on the perfluoro silane compound are capable of reacting for condensation together with the CA, superhydrophobic nanofibrous mat is obtained via electrospinning. This structural modification led to the facile fabrication of the novel oil/water nanofibrous separator which functions effectively demonstrated by hexane/oil and water separation experiments. Perfluoro groups consequently modified the hydrophilic CA nanofibers into superhydrophobic character and therefore FS/CA-NF could be quite practical for future applications like water/oil separators, as well as self-cleaning or water resistant nanofibrous structures. PMID:27398738

  14. Polyelectrolyte multilayer film-assisted formation of zero-valent iron nanoparticles onto polymer nanofibrous mats

    International Nuclear Information System (INIS)

    A facile approach that combines the electrospinning technique and layer-by-layer (LbL) assembly method has been developed to synthesize and immobilize zero-valent iron nanoparticles (ZVI NPs) onto the surface of nanofibers for potential environmental applications. In this approach, negatively charged cellulose acetate (CA) nanofibers fabricated by electrospinning CA solution were modified with bilayers composed of positively charged poly(diallyl-dimethyl-ammoniumchloride) (PDADMAC) and negatively charged poly(acrylic acid) (PAA) through electrostatic LbL assembly approach to form composite nanofibrous mats. The composite nanofibrous mats were immersed into the ferrous iron solution to allow Fe(II) ions to complex with the free carboxyl groups of PAA, and then ZVI NPs were immobilized onto the composite nanofibrous mats instantly by reducing the ferrous cations. Combined scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and thermogravimetry analysis demonstrated that the ZVI NPs are successfully synthesized and uniformly distributed into the polyelectrolyte (PE) multilayer films assembled onto the CA nanofibers. The present approach to synthesis ZVI NPs opens a new avenue to fabricating various materials with high surface area for environmental, catalytic, and sensing applications.

  15. Fabrication and Formation Mechanism of Ag Nanoplate-Decorated Nanofiber Mats and Their Application in SERS.

    Science.gov (United States)

    Jia, Peng; Chang, Jiao; Wang, Jianqiang; Zhang, Pan; Cao, Bing; Geng, Yuting; Wang, Xiuxing; Pan, Kai

    2016-01-01

    We report a new simple method to fabricate a highly active SERS substrate consisting of poly-m-phenylenediamine/polyacrylonitrile (PmPD/PAN) decorated with Ag nanoplates. The formation mechanism of Ag nanoplates is investigated. The synthetic process of the Ag nanoplate-decorated PmPD/PAN (Ag nanoplates@PmPD/PAN) nanofiber mats consists of the assembly of Ag nanoparticles on the surface of PmPD/PAN nanofibers as crystal nuclei followed by in situ growth of Ag nanoparticles exclusively into nanoplates. Both the reducibility of the polymer and the concentration of AgNO3 are found to play important roles in the formation and the density of Ag nanoplates. The optimized Ag nanoplates@PmPD/PAN nanofiber mats exhibit excellent activity and reproducibility in surface-enhanced Raman scattering (SERS) detection of 4-mercaptobenzoic acid (4-MBA) with a detection limit of 10(-10)  m, making the Ag nanoplates@PmPD/PAN nanofiber mats a promising substrate for SERS detection of chemical molecules. In addition, this work also provides a design and fabrication process for a 3D SERS substrate made of a reducible polymer with noble metals. PMID:26395245

  16. An Energy Balance Model to Predict Chemical Partitioning in a Photosynthetic Microbial Mat

    Science.gov (United States)

    Hoehler, Tori M.; Albert, Daniel B.; DesMarais, David J.

    2006-01-01

    Studies of biosignature formation in photosynthetic microbial mat communities offer potentially useful insights with regards to both solar and extrasolar astrobiology. Biosignature formation in such systems results from the chemical transformation of photosynthetically fixed carbon by accessory microorganisms. This fixed carbon represents a source not only of reducing power, but also energy, to these organisms, so that chemical and energy budgets should be coupled. We tested this hypothesis by applying an energy balance model to predict the fate of photosynthetic productivity under dark, anoxic conditions. Fermentation of photosynthetically fixed carbon is taken to be the only source of energy available to cyanobacteria in the absence of light and oxygen, and nitrogen fixation is the principal energy demand. The alternate fate for fixed carbon is to build cyanobacterial biomass with Redfield C:N ratio. The model predicts that, under completely nitrogen-limited conditions, growth is optimized when 78% of fixed carbon stores are directed into fermentative energy generation, with the remainder allocated to growth. These predictions were compared to measurements made on microbial mats that are known to be both nitrogen-limited and populated by actively nitrogen-fixing cyanobacteria. In these mats, under dark, anoxic conditions, 82% of fixed carbon stores were diverted into fermentation. The close agreement between these independent approaches suggests that energy balance models may provide a quantitative means of predicting chemical partitioning within such systems - an important step towards understanding how biological productivity is ultimately partitioned into biosignature compounds.

  17. LHCb Scintillating Fibre Tracker Engineering Design Review Report: Fibres, Mats and Modules

    CERN Document Server

    Joram, Christian; Leverington, Blake Dean; Kirn, Thomas; Bachmann, Sebastian; Ekelhof, Robert Jan; Müller, Janine

    2015-01-01

    During the Long Shutdown 2 of the LHC, the LHCb collaboration will replace the current Outer and Inner Tracker by a single tracking detector, based on 2.42m long scintillating fibres with a diameter of 250 $\\mu$m, readout by silicon photo-multipliers (SiPM). The fibers are arranged in mats of 6 fibre-layers with a width of 130.65 mm. Eight fibre mats will form a module and are sandwiched between honeycomb and carbon fibre composite panels to provide stability and support over the module length of 4.85m. At either end of the module are the interfaces to the SiPMs and the front-end electronics. The active detection area of the Scintillating Fiber Tracker (SciFi) of 360m$^2$ will comprise 144 single modules arranged in 12 detection planes. This document summarizes the engineering design of the fibre mats and of the modules including the interfaces to the SiPMs and the mounting to the detector frames. Mechanical and detector properties of several prototype modules are discussed. The production procedure of the fi...

  18. A natural view of microbial biodiversity within hot spring cyanobacterial mat communities

    Science.gov (United States)

    Ward, D. M.; Ferris, M. J.; Nold, S. C.; Bateson, M. M.

    1998-01-01

    This review summarizes a decade of research in which we have used molecular methods, in conjunction with more traditional approaches, to study hot spring cyanobacterial mats as models for understanding principles of microbial community ecology. Molecular methods reveal that the composition of these communities is grossly oversimplified by microscopic and cultivation methods. For example, none of 31 unique 16S rRNA sequences detected in the Octopus Spring mat, Yellowstone National Park, matches that of any prokaryote previously cultivated from geothermal systems; 11 are contributed by genetically diverse cyanobacteria, even though a single cyanobacterial species was suspected based on morphologic and culture analysis. By studying the basis for the incongruity between culture and molecular samplings of community composition, we are beginning to cultivate isolates whose 16S rRNA sequences are readily detected. By placing the genetic diversity detected in context with the well-defined natural environmental gradients typical of hot spring mat systems, the relationship between gene and species diversity is clarified and ecological patterns of species occurrence emerge. By combining these ecological patterns with the evolutionary patterns inherently revealed by phylogenetic analysis of gene sequence data, we find that it may be possible to understand microbial biodiversity within these systems by using principles similar to those developed by evolutionary ecologists to understand biodiversity of larger species. We hope that such an approach guides microbial ecologists to a more realistic and predictive understanding of microbial species occurrence and responsiveness in both natural and disturbed habitats.

  19. Biocidal Activity of Plasma Modified Electrospun Polysulfone Mats Functionalized with Polyethyleneimine-Capped Silver Nanoparticles

    KAUST Repository

    Schiffman, Jessica D.

    2011-11-01

    The incorporation of silver nanoparticles (AgNPs) into polymeric nanofibers has attracted a great deal of attention due to the strong antimicrobial activity that the resulting fibers exhibit. However, bactericidal efficacy of AgNP-coated electrospun fibrous mats has not yet been demonstrated. In this study, polysulfone (PSf) fibers were electrospun and surface-modified using an oxygen plasma treatment, which allowed for facile irreversible deposition of cationically charged polyethyleneimine (PEI)-AgNPs via electrostatic interactions. The PSf-AgNP mats were characterized for relative silver concentration as a function of plasma treatment time using ICP-MS and changes in contact angle. Plasma treatment of 60 s was the shortest time required for maximum loss of bacteria (Escherichia coli) viability. Time-dependent bacterial cytotoxicity studies indicate that the optimized PSf-AgNP mats exhibit a high level of inactivation against both Gram negative bacteria, Escherichia coli, and Gram positive bacteria, Bacillus anthracis and Staphylococcus aureus. © 2011 American Chemical Society.

  20. Oxygen-Dependent Morphogenesis of Modern Clumped Photosynthetic Mats and Implications for the Archean Stromatolite Record

    Directory of Open Access Journals (Sweden)

    Malcolm R. Walter

    2012-10-01

    Full Text Available Some modern filamentous oxygenic photosynthetic bacteria (cyanobacteria form macroscopic tufts, laminated cones and ridges that are very similar to some Archean and Proterozoic stromatolites. However, it remains unclear whether microbes that constructed Archean clumps, tufts, cones and ridges also produced oxygen. Here, we address this question by examining the physiology of cyanobacterial clumps, aggregates ~0.5 mm in diameter that initiate the growth of modern mm- and cm-scale cones. Clumps contain more particulate organic carbon in the form of denser, bowed and bent cyanobacterial filaments, abandoned sheaths and non-cyanobacterial cells relative to the surrounding areas. Increasing concentrations of oxygen in the solution enhance the bending of filaments and the persistence of clumps by reducing the lateral migration of filaments away from clumps. Clumped mats in oxic media also release less glycolate, a soluble photorespiration product, and retain a larger pool of carbon in the mat. Clumping thus benefits filamentous mat builders whose incorporation of inorganic carbon is sensitive to oxygen. The morphogenetic sequence of mm-scale clumps, reticulate ridges and conical stromatolites from the 2.7 Ga Tumbiana Formation likely records similar O2-dependent behaviors, preserving currently the oldest morphological signature of oxygenated environments on Early Earth.

  1. Use of Lightweight Cellular Mats to Reduce the Settlement of Structure on Soft Soil

    Science.gov (United States)

    Ganasan, R.; Lim, A. J. M. S.; Wijeyesekera, D. C.

    2016-07-01

    Construction of structures on soft soils gives rise to some difficulties in Malaysia and other country especially in settlement both in short and long term. The focus of this research is to minimize the differential and non-uniform settlement on peat soil with the use of an innovative cellular mat. The behaviour and performance of the lightweight geo-material (in block form) is critically investigated and in particular the use as a fill in embankment on soft ground. Hemic peat soil, sponge and innovative cellular mat will be used as the main material in this study. The monitoring in settlement behavior from this part of research will be done as laboratory testing only. The uneven settlement in this problem was uniquely monitored photographically using spot markers. In the end of the research, it is seen that the innovative cellular mat has reduce the excessive and differential settlement up to 50% compare to flexible and rigid foundations. This had improve the stiffness of soils as well as the porous contain in cellular structure which help in allowing water/moisture to flow through in or out thus resulting in prevent the condition of floating.

  2. The effectiveness of the 4MAT teaching model upon student achievement and attitude levels

    Directory of Open Access Journals (Sweden)

    Uyangör, Sevinç Mert

    2012-01-01

    Full Text Available 4MAT is an 8-step, sequential instructional model based on two theoretical constructs: Kolb's model of learning styles and the concept of brain hemisphericity. The model, developed by B. McCarthy (1987 is derived by interacting each of Kolb's four quadrants with both left and right brain. The purpose of this study is to examine the influence of the 4MAT teaching model which depends on learning styles that have been generated by the help of the relationship between the brain and learning; and focuses on the learning loop as a centre upon students’ level of mathematics course achievement; and the level of attitudes towards mathematics in the unit of the Hoop and Circle. An experimental pattern model with a pre-test, post-test control group has been used in this research. The sample of this study comprised 81 students from the 7th grade at Public School in Balıkesir during the 2009-2010 education periods. It has been determined that 4MAT method of instruction was more efficient than the traditional method.

  3. 何首乌及其常见混淆品的matK基因序列分析及鉴别%Analysis and Authentication of Fallopia multiflora and Its Adulterants by matK Sequence

    Institute of Scientific and Technical Information of China (English)

    生书晶; 严萍; 郑传进; 赵树进

    2010-01-01

    目的:比较何首乌与其常见混淆品的matK基因序列,从分子水平对中药材何首乌进行鉴定.方法:改良的CTAB法提取基因组DNA,用一对matK通用引物进行PCR扩增,TA克隆后进行测序和序列分析.结果:除毛脉蓼之外,其他混淆品与正品何首乌间的matK基因序列差异较大,不论是核苷酸替代数还是遗传距离,都远远大于不同居群的何首乌之间;进一步比对分析,发现了可以快速鉴别何首乌及其同属混淆品的鉴别位点;运用matK序列分析成功地对3种市售何首乌药材进行了真伪鉴定.结论:根据matK序列特征,能有效区分何首乌及其常见混淆品,matK序列可以作为何首乌药材鉴定的分子标记.

  4. Tunable Structures and Properties of Electrospun Regenerated Silk Fibroin Mats Annealed in Water Vapor at Different Times and Temperatures

    Directory of Open Access Journals (Sweden)

    Xiangyu Huang

    2014-01-01

    Full Text Available Regenerated silk fibroin (SF mats were fabricated using electrospinning technique, followed by mild water vapor annealing to effectively tune the structures and improve the mechanical properties of the mats at different annealing times and temperatures. The breaking strength and the breaking energy of the mats treated with water vapor at 65°C for 12 h reached 6.0 MPa and 171.7 J/kg, respectively. The conformational transition of the SF mats was significantly influenced by the treating temperature, while the influence of time was comparatively limited. The influence is consistent with the time-temperature equivalent principle and would be helpful for the preparation of water-vapor-annealed silk-based biomaterials for various applications.

  5. Expansion rate and geometry of floating vegetation mats on the margins of thermokarst lakes, northern Seward Peninsula, Alaska, USA

    Science.gov (United States)

    Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.

    2011-01-01

    Investigations on the northern Seward Peninsula in Alaska identified zones of recent (expansion. This paper reports on the recent expansion of these collapse features and their geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.

  6. RESIDUAL STRENGTH OF CHOPPED STRAND MAT GLASS FIBRE/EPOXY COMPOSITE STRUCTURES: EFFECT OF TEMPERATURE AND WATER ABSORPTION

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2011-12-01

    Full Text Available The residual strength of chopped strand mat glass fibre/epoxy composites following exposure to different hygrothermal conditions was investigated. All residual tests were carried out according to ASTM D 3479 and D 3039 on tension-tension fatigue with a frequency of 5 Hz, a stress ratio of R= 0.5and maximum stress σmax = 60 MPa. The residual strength curves were used to investigate the strength of chopped strand mat glass fibre/epoxy under the effect of temperature and the interactive environment of water absorption and temperature. The results showed that the chopped strand mat glass fibre/epoxy had high resistance toward tension-tension fatigue loading. However, the degradation of the tensile residual strength of chopped strand mat glass fibre/epoxy was significant with high water absorption at an elevated temperature.

  7. Avasõnad / Mats Estonius, Toomas Hendrik Ilves, Eduardo Ibáñes, Uffe A. Baslev

    Index Scriptorium Estoniae

    2010-01-01

    Konverentsi avasõnad laususid Tallinna Ülikooli prorektor Mats Estonius, Eesti Vabariigi president Toomas Hendrik Ilves, Hispaania Kuningriigi suursaadik Eestis Eduardo Ibáñes, Taani Kuningriigi suursaadik Eestis Uffe A. Baslev

  8. Propulsion System Simulation Using the Toolbox for the Modeling and Analysis of Thermodynamic System T-MATS

    Science.gov (United States)

    Chapman, Jeffryes W.; Lavelle, Thomas M.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

    2014-01-01

    A simulation toolbox has been developed for the creation of both steady-state and dynamic thermodynamic software models. This paper describes the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS), which combines generic thermodynamic and controls modeling libraries with a numerical iterative solver to create a framework for the development of thermodynamic system simulations, such as gas turbine engines. The objective of this paper is to present an overview of T-MATS, the theory used in the creation of the module sets, and a possible propulsion simulation architecture. A model comparison was conducted by matching steady-state performance results from a T-MATS developed gas turbine simulation to a well-documented steady-state simulation. Transient modeling capabilities are then demonstrated when the steady-state T-MATS model is updated to run dynamically.

  9. Propulsion System Simulation Using the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS)

    Science.gov (United States)

    Chapman, Jeffryes W.; Lavelle, Thomas M.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

    2014-01-01

    A simulation toolbox has been developed for the creation of both steady-state and dynamic thermodynamic software models. This paper describes the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS), which combines generic thermodynamic and controls modeling libraries with a numerical iterative solver to create a framework for the development of thermodynamic system simulations, such as gas turbine engines. The objective of this paper is to present an overview of T-MATS, the theory used in the creation of the module sets, and a possible propulsion simulation architecture. A model comparison was conducted by matching steady-state performance results from a T-MATS developed gas turbine simulation to a well-documented steady-state simulation. Transient modeling capabilities are then demonstrated when the steady-state T-MATS model is updated to run dynamically.

  10. Characterization of Geographically Distinct Bacterial Communities Associated with Coral Mucus Produced by Acropora spp. and Porites spp.

    OpenAIRE

    McKew, B.A.; Dumbrell, A.J.; Daud, S. D.; Hepburn, L; Thorpe, E.; Mogensen, L.; Whitby, C.

    2012-01-01

    Acropora and Porites corals are important reef builders in the Indo-Pacific and Caribbean. Bacteria associated with mucus produced by Porites spp. and Acropora spp. from Caribbean (Punta Maroma, Mexico) and Indo-Pacific (Hoga and Sampela, Indonesia) reefs were determined. Analysis of pyrosequencing libraries showed that bacterial communities from Caribbean corals were significantly more diverse (H′, 3.18 to 4.25) than their Indonesian counterparts (H′, 2.54 to 3.25). Dominant taxa were Gammap...

  11. Antimicrobial activity of the essential oil of Cymbopogon citratus (DC) Stapf. on Staphylococcus spp., Streptococcus mutans and Candida spp.

    OpenAIRE

    RBA Almeida; G Akisue; LML Cardoso; JC Junqueira; AO C Jorge

    2013-01-01

    Medicinal plants with fungicide action, antibacterial and anti-inflammatory effects are under investigation. The main purpose of this work was to evaluate the antimicrobial activity of the essential oil from Cymbopogon citratus (DC) Stapf. on strains of Staphylococcus spp., Streptococcus mutans and Candida spp. with planktonic and biofilm growth. To study the micro-organisms in planktonic cells, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were deter...

  12. The Effect of Co-Administration of Death Camas (Zigadenus spp.) and Low Larkspur (Delphinium spp.) in Cattle

    OpenAIRE

    Welch, Kevin D.; Green, Benedict T.; Gardner, Dale R.; Stonecipher, Clinton A.; James A. Pfister; Daniel Cook

    2016-01-01

    In many rangeland settings, there is more than one potential poisonous plant. Two poisonous plants that are often found growing simultaneously in the same location in North American rangelands are death camas (Zigadenus spp.) and low larkspur (Delphinium spp.). The objective of this study was to determine if co-administration of death camas would exacerbate the toxicity of low larkspur in cattle. Cattle dosed with 2.0 g of death camas/kg BW showed slight frothing and lethargy, whereas cattle ...

  13. Dosimetric comparison of 3D conformal, IMRT, and V-MAT techniques for accelerated partial-breast irradiation (APBI)

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jian-Jian [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai (China); Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Chang, Zheng; Horton, Janet K.; Wu, Qing-Rong Jackie; Yoo, Sua [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Yin, Fang-Fang, E-mail: fangfang.yin@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

    2014-07-01

    The purpose is to dosimetrically compare the following 3 delivery techniques: 3-dimensional conformal radiation therapy (3D-CRT), intensity-modulated arc therapy (IMRT), and volumetric-modulated arc therapy (V-MAT) in the treatment of accelerated partial-breast irradiation (APBI). Overall, 16 patients with T1/2N0 breast cancer were treated with 3D-CRT (multiple, noncoplanar photon fields) on the RTOG 0413 partial-breast trial. These cases were subsequently replanned using static gantry IMRT and V-MAT technology to understand dosimetric differences among these 3 techniques. Several dosimetric parameters were used in plan quality evaluation, including dose conformity index (CI) and dose-volume histogram analysis of normal tissue coverage. Quality assurance studies including gamma analysis were performed to compare the measured and calculated dose distributions. The IMRT and V-MAT plans gave more conformal target dose distributions than the 3D-CRT plans (p < 0.05 in CI). The volume of ipsilateral breast receiving 5 and 10 Gy was significantly less using the V-MAT technique than with either 3D-CRT or IMRT (p < 0.05). The maximum lung dose and the ipsilateral lung volume receiving 10 (V{sub 10}) or 20 Gy (V{sub 20}) were significantly less with both V-MAT and IMRT (p < 0.05). The IMRT technique was superior to 3D-CRT and V-MAT of low dose distributions in ipsilateral lung (p < 0.05 in V{sub 5} and D{sub 5}). The total mean monitor units (MUs) for V-MAT (621.0 ± 111.9) were 12.2% less than those for 3D-CRT (707.3 ± 130.9) and 46.5% less than those for IMRT (1161.4 ± 315.6) (p < 0.05). The average machine delivery time was 1.5 ± 0.2 minutes for the V-MAT plans, 7.0 ± 1.6 minutes for the 3D-CRT plans, and 11.5 ± 1.9 minutes for the IMRT plans, demonstrating much less delivery time for V-MAT. Based on this preliminary study, V-MAT and IMRT techniques offer improved dose conformity as compared with 3D-CRT techniques without increasing dose to the ipsilateral lung. In

  14. Evaluation of HiMAT aircraft landing approach lateral control gearing using simulation and a visual display

    Science.gov (United States)

    Sarrafian, S. K.

    1984-01-01

    The utility of a visual display when studying the influence of changes in lateral stick gearing gains on the Highly Maneuverable Aircraft Technology (HiMAT) vehicle handling qualities during simulated approaches and landings is investigated. The visual display improved the validity of the simulation and provided improved roll response cues for the HiMAT aircraft landing approach. A range of acceptable constant lateral stick gearing gains is found that provides adequate maneuverability and allows for precision moments.

  15. Dynamics of bacterial populations during bench‐scale bioremediation of oily seawater and desert soil bioaugmented with coastal microbial mats

    OpenAIRE

    Ali, Nidaa; Dashti, Narjes; Salamah, Samar; Sorkhoh, Naser; Al‐Awadhi, Husain; Samir RADWAN

    2016-01-01

    Summary This study describes a bench‐scale attempt to bioremediate Kuwaiti, oily water and soil samples through bioaugmentation with coastal microbial mats rich in hydrocarbonoclastic bacterioflora. Seawater and desert soil samples were artificially polluted with 1% weathered oil, and bioaugmented with microbial mat suspensions. Oil removal and microbial community dynamics were monitored. In batch cultures, oil removal was more effective in soil than in seawater. Hydrocarbonoclastic bacteria ...

  16. Professor Mats Larsson 60 år : En dokumentation från ett hyllningsseminarium i oktober 2013

    OpenAIRE

    2014-01-01

    To congratulate Professor Mats Larsson on the occasion of his 60th birthday, the Departmentof Economic History, Uppsala University, arranged a seminar in his honour in the fall of2013. Speakers representing business administration and economic history from a number ofSwedish universities spoke on a range of subjects touching upon Mats Larsson’s own researchinterests such as business history, banking history, economic history and biography. Thepresent volume includes the lectures and the follo...

  17. Timescales of Growth Response of Microbial Mats to Environmental Change in an Ice-Covered Antarctic Lake

    Directory of Open Access Journals (Sweden)

    Anne D. Jungblut

    2013-01-01

    Full Text Available Lake Vanda is a perennially ice-covered, closed-basin lake in the McMurdo Dry Valleys, Antarctica. Laminated photosynthetic microbial mats cover the floor of the lake from below the ice cover to >40 m depth. In recent decades, the water level of Lake Vanda has been rising, creating a “natural experiment” on development of mat communities on newly flooded substrates and the response of deeper mats to declining irradiance. Mats in recently flooded depths accumulate one lamina (~0.3 mm per year and accrue ~0.18 µg chlorophyll-a cm−2 y−1. As they increase in thickness, vertical zonation becomes evident, with the upper 2-4 laminae forming an orange-brown zone, rich in myxoxanthophyll and dominated by intertwined Leptolyngbya trichomes. Below this, up to six phycobilin-rich green/pink-pigmented laminae form a subsurface zone, inhabited by Leptolyngbya, Oscillatoria and Phormidium morphotypes. Laminae continued to increase in thickness for several years after burial, and PAM fluorometry indicated photosynthetic potential in all pigmented laminae. At depths that have been submerged for >40 years, mats showed similar internal zonation and formed complex pinnacle structures that were only beginning to appear in shallower mats. Chlorophyll-a did not change over time and these mats appear to represent resource-limited “climax” communities. Acclimation of microbial mats to changing environmental conditions is a slow process, and our data show how legacy effects of past change persist into the modern community structure.

  18. Influence of Pilates Mat and Apparatus Exercises on Pain and Balance of Businesswomen with Chronic Low Back Pain

    OpenAIRE

    Lee, Chae-Woo; Hyun, Ju; Kim, Seong Gil

    2014-01-01

    [Purpose] The purpose of this study was to examine the influence of mat Pilates and apparatus Pilates on pain and static balance of businesswomen with chronic back pain. [Subjects and Methods] Participants were randomly allocated to Pilates mat exercises (PME) or Pilates apparatus exercise (PAE), and performed the appropriate Pilates exercises 3 days per week for 8 weeks. In order to measure the improvement in the participants’ static balance ability as a result of the exercise, the sway leng...

  19. MatVPC: A User-Friendly MATLAB-Based Tool for the Simulation and Evaluation of Systems Pharmacology Models

    OpenAIRE

    Biliouris, Kostas; Lavielle, Marc; Trame, Mirjam

    2015-01-01

    International audience Quantitative systems pharmacology (QSP) models are progressively entering the arena of contemporary pharmacology. The efficient implementation and evaluation of complex QSP models necessitates the development of flexible computational tools that are built into QSP mainstream software. To this end, we present MatVPC, a versatile MATLAB-based tool that accommodates QSP models of any complexity level. MatVPC executes Monte Carlo simulations as well as automatic construc...

  20. Contrasted effects of natural complex mixtures of PAHs and metals on oxygen cycle in a microbial mat

    OpenAIRE

    Pringault, Olivier; Aube, J.; Bouchez, O.; Klopp, C.; Mariette, J.; Escudie, F.; Senin, P.; Goni-Urriza, M.

    2015-01-01

    The contamination of polluted environments is often due to a complex mixture of pollutants sometimes at trace levels which nevertheless may have significant effects on the diversity and functioning of organisms. The aim of this study was to assess the functional responses of a microbial mat exposed to a natural complex mixture of PAHs and metals as a function of the maturation stage of the biofilm. Microbial mats sampled in a slightly polluted environment were exposed to contaminated water of...