WorldWideScience

Sample records for drive microbial colonization

  1. Microbial Surface Colonization and Biofilm Development in Marine Environments

    Science.gov (United States)

    2015-01-01

    SUMMARY Biotic and abiotic surfaces in marine waters are rapidly colonized by microorganisms. Surface colonization and subsequent biofilm formation and development provide numerous advantages to these organisms and support critical ecological and biogeochemical functions in the changing marine environment. Microbial surface association also contributes to deleterious effects such as biofouling, biocorrosion, and the persistence and transmission of harmful or pathogenic microorganisms and their genetic determinants. The processes and mechanisms of colonization as well as key players among the surface-associated microbiota have been studied for several decades. Accumulating evidence indicates that specific cell-surface, cell-cell, and interpopulation interactions shape the composition, structure, spatiotemporal dynamics, and functions of surface-associated microbial communities. Several key microbial processes and mechanisms, including (i) surface, population, and community sensing and signaling, (ii) intraspecies and interspecies communication and interaction, and (iii) the regulatory balance between cooperation and competition, have been identified as critical for the microbial surface association lifestyle. In this review, recent progress in the study of marine microbial surface colonization and biofilm development is synthesized and discussed. Major gaps in our knowledge remain. We pose questions for targeted investigation of surface-specific community-level microbial features, answers to which would advance our understanding of surface-associated microbial community ecology and the biogeochemical functions of these communities at levels from molecular mechanistic details through systems biological integration. PMID:26700108

  2. Microbial colonization of silicone voice prostheses used in laryngectomized patients

    NARCIS (Netherlands)

    Eerenstein, S. E.; Grolman, W.; Schouwenburg, P. F.

    1999-01-01

    The aim of this study was to identify the microbial colonization of dysfunctioning voice prostheses in laryngectomized patients and determine the influence of patient radiation therapy on prosthesis life span. In a 40-month period, 257 outpatient voice prosthesis replacements were carried out in a

  3. Microbial Mineral Colonization Across a Subsurface Redox Transition Zone

    Directory of Open Access Journals (Sweden)

    Brandon eConverse

    2015-08-01

    Full Text Available This study employed 16S rRNA gene amplicon pyrosequencing to examine the hypothesis that chemolithotrophic Fe(II-oxidizing bacteria (FeOB would preferentially colonize the Fe(II-bearing mineral biotite compared to quartz sand when the minerals were incubated in situ within a subsurface redox transition zone (RTZ at the Hanford 300 Area site in Richland, WA, USA. The work was motivated by the recently documented presence of neutral-pH chemolithotrophic FeOB capable of oxidizing structural Fe(II in primary silicate and secondary phyllosilicate minerals in 300 Area sediments and groundwater (Benzine et al., 2013. Sterilized portions of sand+biotite or sand alone were incubated in situ for five months within a multilevel sampling (MLS apparatus that spanned a ca. 2-m interval across the RTZ in two separate groundwater wells. Parallel MLS measurements of aqueous geochemical species were performed prior to deployment of the minerals. Contrary to expectations, the 16S rRNA gene libraries showed no significant difference in microbial communities that colonized the sand+biotite versus sand-only deployments. Both mineral-associated and groundwater communities were dominated by heterotrophic taxa, with organisms from the Pseudomonaceae accounting for up to 70% of all reads from the colonized minerals. These results are consistent with previous results indicating the capacity for heterotrophic metabolism (including anaerobic metabolism below the RTZ as well as the predominance of heterotrophic taxa within 300 Area sediments and groundwater. Although heterotrophic organisms clearly dominated the colonized minerals, several putative lithotrophic (NH4+, H2, Fe(II, and HS- oxidizing taxa were detected in significant abundance above and within the RTZ. Such organisms may play a role in the coupling of anaerobic microbial metabolism to oxidative pathways with attendant impacts on elemental cycling and redox-sensitive contaminant behavior in the vicinity of the

  4. Microbial Populations of Stony Meteorites: Substrate Controls on First Colonizers

    Directory of Open Access Journals (Sweden)

    Alastair W. Tait

    2017-06-01

    Full Text Available Finding fresh, sterilized rocks provides ecologists with a clean slate to test ideas about first colonization and the evolution of soils de novo. Lava has been used previously in first colonizer studies due to the sterilizing heat required for its formation. However, fresh lava typically falls upon older volcanic successions of similar chemistry and modal mineral abundance. Given enough time, this results in the development of similar microbial communities in the newly erupted lava due to a lack of contrast between the new and old substrates. Meteorites, which are sterile when they fall to Earth, provide such contrast because their reduced and mafic chemistry commonly differs to the surfaces on which they land; thus allowing investigation of how community membership and structure respond to this new substrate over time. We conducted 16S rRNA gene analysis on meteorites and soil from the Nullarbor Plain, Australia. We found that the meteorites have low species richness and evenness compared to soil sampled from directly beneath each meteorite. Despite the meteorites being found kilometers apart, the community structure of each meteorite bore more similarity to those of other meteorites (of similar composition than to the community structure of the soil on which it resided. Meteorites were dominated by sequences that affiliated with the Actinobacteria with the major Operational Taxonomic Unit (OTU classified as Rubrobacter radiotolerans. Proteobacteria and Bacteroidetes were the next most abundant phyla. The soils were also dominated by Actinobacteria but to a lesser extent than the meteorites. We also found OTUs affiliated with iron/sulfur cycling organisms Geobacter spp. and Desulfovibrio spp. This is an important finding as meteorites contain abundant metal and sulfur for use as energy sources. These ecological findings demonstrate that the structure of the microbial community in these meteorites is controlled by the substrate, and will not

  5. Patterns of Early-Life Gut Microbial Colonization during Human Immune Development: An Ecological Perspective

    Directory of Open Access Journals (Sweden)

    Isabelle Laforest-Lapointe

    2017-07-01

    Full Text Available Alterations in gut microbial colonization during early life have been reported in infants that later developed asthma, allergies, type 1 diabetes, as well as in inflammatory bowel disease patients, previous to disease flares. Mechanistic studies in animal models have established that microbial alterations influence disease pathogenesis via changes in immune system maturation. Strong evidence points to the presence of a window of opportunity in early life, during which changes in gut microbial colonization can result in immune dysregulation that predisposes susceptible hosts to disease. Although the ecological patterns of microbial succession in the first year of life have been partly defined in specific human cohorts, the taxonomic and functional features, and diversity thresholds that characterize these microbial alterations are, for the most part, unknown. In this review, we summarize the most important links between the temporal mosaics of gut microbial colonization and the age-dependent immune functions that rely on them. We also highlight the importance of applying ecology theory to design studies that explore the interactions between this complex ecosystem and the host immune system. Focusing research efforts on understanding the importance of temporally structured patterns of diversity, keystone groups, and inter-kingdom microbial interactions for ecosystem functions has great potential to enable the development of biologically sound interventions aimed at maintaining and/or improving immune system development and preventing disease.

  6. The first microbial colonizers of the human gut

    NARCIS (Netherlands)

    Milani, Christian; Duranti, Sabrina; Bottacini, Francesca; Casey, Eoghan; Turroni, Francesca; Mahony, Jennifer; Belzer, Clara; Palacio, Susana Delgado; Montes, Silvia Arboleya; Mancabelli, Leonardo; Lugli, Gabriele Andrea; Rodriguez, Juan Miguel; Bode, Lars; Vos, De Willem; Gueimonde, Miguel; Margolles, Abelardo; Sinderen, Van Douwe; Ventura, Marco

    2017-01-01

    The human gut microbiota is engaged in multiple interactions affecting host health during the host's entire life span. Microbes colonize the neonatal gut immediately following birth. The establishment and interactive development of this early gut microbiota are believed to be (at least partially)

  7. Microbial biomass in compost during colonization of Agaricus bisporus

    NARCIS (Netherlands)

    Vos, Aurin M.; Heijboer, Amber; Boschker, Henricus T.S.; Bonnet, Barbara; Lugones, Luis G.; Wösten, Han A.B.

    2017-01-01

    Agaricus bisporus mushrooms are commercially produced on a microbe rich compost. Here, fungal and bacterial biomass was quantified in compost with and without colonization by A. bisporus. Chitin content, indicative of total fungal biomass, increased during a 26-day period from 576 to 779 nmol

  8. Anaplasma phagocytophilum Dihydrolipoamide Dehydrogenase 1 Affects Host-Derived Immunopathology during Microbial Colonization

    Czech Academy of Sciences Publication Activity Database

    Chen, G.; Severo, M. S.; Sakhon, O. S.; Choy, A.; Herron, M. J.; Felsheim, R. F.; Wiryawan, H.; Liao, J.; Johns, J. L.; Munderloh, U. G.; Sutterwala, F. S.; Kotsyfakis, Michalis; Pedra, J. H. F.

    2012-01-01

    Roč. 80, č. 9 (2012), s. 3194-3205 ISSN 0019-9567 Institutional support: RVO:60077344 Keywords : ricketsia * microbial colonization * immunopathology * inflammation * signaling pathways Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.074, year: 2012 http://iai. asm .org/content/80/9/3194

  9. MICROBIAL COLONIZATION, RESPIRATION, AND BREAKDOWN OF MAPLE LEAVES ALONG A STREAM-MARSH CONTINUUM

    Science.gov (United States)

    Breakdown rates, macroinvertebrate and bacterial colonization, and microbial respiration were measured on decaying maple (Acer saccharum) leaves at three sites along a stream-marsh continuum. Breakdown rates (-k+-SE) were 0.0284+-0.0045 d-1 for leaves in a high-gradient, non-tida...

  10. Context-dependent colonization dynamics: Regional reward contagion drives local compression in aquatic beetles.

    Science.gov (United States)

    Pintar, Matthew R; Resetarits, William J

    2017-09-01

    Habitat selection by colonizing organisms is an important factor in determining species abundance and community dynamics at multiple spatial scales. Many organisms select habitat patches based on intrinsic patch quality, but patches exist in complex landscapes linked by dispersal and colonization, forming metapopulations and metacommunities. Perceived patch quality can be influenced by neighbouring patches through spatial contagion, wherein perceived quality of one patch can extend beyond its borders and either increase or decrease the colonization of neighbouring patches and localities. These spatially explicit colonization dynamics can result in habitat compression, wherein more colonists occupy a patch or locality than in the absence of spatial context dependence. Previous work on contagion/compression focused primarily on the role of predators in driving colonization patterns. Our goal was to determine whether resource abundance can drive multi-scale colonization dynamics of aquatic beetles through the processes of contagion and compression in naturally colonized experimental pools. We established two levels (high/low quality) of within-patch resource abundances (leaf litter) using an experimental landscape of mesocosms, and assayed colonization by 35 species of aquatic beetles. Patches were arranged in localities (sets of two patches), which consisted of a combination of two patch-level resource levels in a 2 × 2 factorial design, allowing us to assay colonization at both locality and patch levels. We demonstrate that patterns of species abundance and richness of colonizing aquatic beetles are determined by patch quality and context-dependent processes at multiple spatial scales. Localities that consisted of at least one high-quality patch were colonized at equivalent rates that were higher than localities containing only low-quality patches, displaying regional reward contagion. In localities that consisted of one high- and one low-quality patch, reward

  11. Microbial pathways in colonic sulfur metabolism and links with health and disease

    Directory of Open Access Journals (Sweden)

    Franck eCarbonero

    2012-11-01

    Full Text Available Sulfur is both crucial to life and a potential threat to health. While colonic sulfur metabolism mediated by eukaryotic cells is relatively well studied, much less is known about sulfur metabolism within gastrointestinal microbes. Sulfated compounds in the colon are either of inorganic (e.g., sulfates, sulfites or organic (e.g., dietary amino acids and host mucins origin. The most extensively studied of the microbes involved in colonic sulfur metabolism are the sulfate-reducing bacteria, which are common colonic inhabitants. Many other microbial pathways are likely to shape colonic sulfur metabolism as well as the composition and availability of sulfated compounds, and these interactions need to be examined in more detail. Hydrogen sulfide is the sulfur derivative that has attracted the most attention in the context of colonic health, and the extent to which it is detrimental or beneficial remains in debate. Several lines of evidence point to sulfate-reducing bacteria or exogenous hydrogen sulfide as potential players in the etiology of intestinal disorders, inflammatory bowel diseases and colorectal cancer in particular. Generation of hydrogen sulfide via pathways other than dissimilatory sulfate reduction may be as, or more, important than those involving the sulfate-reducing bacteria. We suggest here that a novel axis of research is to assess the effects of hydrogen sulfide in shaping colonic microbiome structure. Clearly, in-depth characterization of the microbial pathways involved in colonic sulfur metabolism is necessary for a better understanding of its contribution to colonic disorders and development of therapeutic strategies.

  12. 170 pattern of microbial colonization of the vagina of diabetics

    African Journals Online (AJOL)

    boaz

    sensitivity of high vaginal swabs from 60 consecutive non-insulin-dependent diabetics and 20 non-diabetics attending Oluyoro Catholic ... tuberculosis and acute cholecystitis16. The lower genital flora may act .... TABLE I: AGE, FASTING PLASMA GLUCOSE, DURATION OF DIABETES AND MICROBIAL. ISOLATES FROM ...

  13. Membrane biofouling in a wastewater nitrification reactor: Microbial succession from autotrophic colonization to heterotrophic domination.

    Science.gov (United States)

    Lu, Huijie; Xue, Zheng; Saikaly, Pascal; Nunes, Suzana P; Bluver, Ted R; Liu, Wen-Tso

    2016-01-01

    Membrane biofouling is a complex process that involves bacterial adhesion, extracellular polymeric substances (EPS) excretion and utilization, and species interactions. To obtain a better understanding of the microbial ecology of biofouling process, this study conducted rigorous, time-course analyses on the structure, EPS and microbial composition of the fouling layer developed on ultrafiltration membranes in a nitrification bioreactor. During a 14-day fouling event, three phases were determined according to the flux decline and microbial succession patterns. In Phase I (0-2 days), small sludge flocs in the bulk liquid were selectively attached on membrane surfaces, leading to the formation of similar EPS and microbial community composition as the early biofilms. Dominant populations in small flocs, e.g., Nitrosomonas, Nitrobacter, and Acinetobacter spp., were also the major initial colonizers on membranes. In Phase II (2-4 d), fouling layer structure, EPS composition, and bacterial community went through significant changes. Initial colonizers were replaced by fast-growing and metabolically versatile heterotrophs (e.g., unclassified Sphingobacteria). The declining EPS polysaccharide to protein (PS:PN) ratios could be correlated well with the increase in microbial community diversity. In Phase III (5-14 d), heterotrophs comprised over 90% of the community, whereas biofilm structure and EPS composition remained relatively stable. In all phases, AOB and NOB were constantly found within the top 40% of the fouling layer, with the maximum concentrations around 15% from the top. The overall microbial succession pattern from autotrophic colonization to heterotrophic domination implied that MBR biofouling could be alleviated by forming larger bacterial flocs in bioreactor suspension (reducing autotrophic colonization), and by designing more specific cleaning procedures targeting dominant heterotrophs during typical filtration cycles. Copyright © 2015 Elsevier Ltd. All

  14. Membrane biofouling in a wastewater nitrification reactor: microbial succession from autotrophic colonization to heterotrophic domination

    KAUST Repository

    Lu, Huijie

    2015-10-22

    Membrane biofouling is a complex process that involves bacterial adhesion, extracellular polymeric substances (EPS) excretion and utilization, and species interactions. To obtain a better understanding of the microbial ecology of biofouling process, this study conducted rigorous, time-course analyses on the structure, EPS and microbial composition of the fouling layer developed on ultrafiltration membranes in a nitrification bioreactor. During a 14-day fouling event, three phases were determined according to the flux decline and microbial succession patterns. In Phase I (0-2 days), small sludge flocs in the bulk liquid were selectively attached on membrane surfaces, leading to the formation of similar EPS and microbial community composition as the early biofilms. Dominant populations in small flocs, e.g., Nitrosomonas, Nitrobacter, and Acinetobacter spp., were also the major initial colonizers on membranes. In Phase II (2-4 d), fouling layer structure, EPS composition, and bacterial community went through significant changes. Initial colonizers were replaced by fast-growing and metabolically versatile heterotrophs (e.g., unclassified Sphingobacteria). The declining EPS polysaccharide to protein (PS:PN) ratios could be correlated well with the increase in microbial community diversity. In Phase III (5-14 d), heterotrophs comprised over 90% of the community, whereas biofilm structure and EPS composition remained relatively stable. In all phases, AOB and NOB were constantly found within the top 40% of the fouling layer, with the maximum concentrations around 15% from the top. The overall microbial succession pattern from autotrophic colonization to heterotrophic domination implied that MBR biofouling could be alleviated by forming larger bacterial flocs in bioreactor suspension (reducing autotrophic colonization), and by designing more specific cleaning procedures targeting dominant heterotrophs during typical filtration cycles.

  15. Investigation of the microbial communities colonizing prepainted steel used for roofing and walling.

    Science.gov (United States)

    Huynh, Tran T; Jamil, Ili; Pianegonda, Nicole A; Blanksby, Stephen J; Barker, Philip J; Manefield, Mike; Rice, Scott A

    2017-04-01

    Microbial colonization of prepainted steel, commonly used in roofing applications, impacts their aesthetics, durability, and functionality. Understanding the relevant organisms and the mechanisms by which colonization occurs would provide valuable information that can be subsequently used to design fouling prevention strategies. Here, next-generation sequencing and microbial community finger printing (T-RFLP) were used to study the community composition of microbes colonizing prepainted steel roofing materials at Burrawang, Australia and Kapar, Malaysia over a 52-week period. Community diversity was low and was dominated by Bacillus spp., cyanobacteria, actinobacteria, Cladosporium sp., Epicoccum nigrum, and Teratosphaeriaceae sp. Cultivation-based methods isolated approximately 20 different fungi and bacteria, some of which, such as E. nigrum and Cladosporium sp., were represented in the community sequence data. Fluorescence in situ hybridization imaging showed that fungi were the most dominant organisms present. Analysis of the sequence and T-RFLP data indicated that the microbial communities differed significantly between locations and changed significantly over time. The study demonstrates the utility of molecular ecology tools to identify and characterize microbial communities associated with the fouling of painted steel surfaces and ultimately can enable the targeted development of control strategies based on the dominant species responsible for fouling. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  16. Characterization of microbial communities in pest colonized books by molecular biology tools

    OpenAIRE

    Franco Palla

    2011-01-01

    This work presents the identification of bacteria and fungi colonies in insect infesting books, by cultural-independent methodologies based on molecular biology techniques. Microbial genomic DNA extraction, in vitro amplification of specific target sequences by polymerase chain reactions (PCR), sequencing and sequence analysis were performed. These procedures minimized the samples amount, optimized the diagnostic studies on bacteria and fungi colonization and allowed the identification of man...

  17. Gut microbial colonization orchestrates TLR2 expression, signaling and epithelial proliferation in the small intestinal mucosa.

    Directory of Open Access Journals (Sweden)

    Nives Hörmann

    Full Text Available The gut microbiota is an environmental factor that determines renewal of the intestinal epithelium and remodeling of the intestinal mucosa. At present, it is not resolved if components of the gut microbiota can augment innate immune sensing in the intestinal epithelium via the up-regulation of Toll-like receptors (TLRs. Here, we report that colonization of germ-free (GF Swiss Webster mice with a complex gut microbiota augments expression of TLR2. The microbiota-dependent up-regulation of components of the TLR2 signaling complex could be reversed by a 7 day broad-spectrum antibiotic treatment. TLR2 downstream signaling via the mitogen-activated protein kinase (ERK1/2 and protein-kinase B (AKT induced by bacterial TLR2 agonists resulted in increased proliferation of the small intestinal epithelial cell line MODE-K. Mice that were colonized from birth with a normal gut microbiota (conventionally-raised; CONV-R showed signs of increased small intestinal renewal and apoptosis compared with GF controls as indicated by elevated mRNA levels of the proliferation markers Ki67 and Cyclin D1, elevated transcripts of the apoptosis marker Caspase-3 and increased numbers of TUNEL-positive cells per intestinal villus structure. In accordance, TLR2-deficient mice showed reduced proliferation and reduced apoptosis. Our findings suggest that a tuned proliferation response of epithelial cells following microbial colonization could aid to protect the host from its microbial colonizers and increase intestinal surface area.

  18. Colonization patterns of soil microbial communities in the Atacama Desert.

    Science.gov (United States)

    Crits-Christoph, Alexander; Robinson, Courtney K; Barnum, Tyler; Fricke, W Florian; Davila, Alfonso F; Jedynak, Bruno; McKay, Christopher P; Diruggiero, Jocelyne

    2013-11-20

    The Atacama Desert is one of the driest deserts in the world and its soil, with extremely low moisture, organic carbon content, and oxidizing conditions, is considered to be at the dry limit for life. Analyses of high throughput DNA sequence data revealed that bacterial communities from six geographic locations in the hyper-arid core and along a North-South moisture gradient were structurally and phylogenetically distinct (ANOVA test for observed operating taxonomic units at 97% similarity (OTU0.03), P microbial communities' diversity metrics (least squares linear regression for observed OTU0.03 and air RH and soil conductivity, P PCoA Spearman's correlation for air RH and soil conductivity, P <0.0001), indicating that water availability and salt content are key factors in shaping the Atacama soil microbiome. Mineralization studies showed communities actively metabolizing in all soil samples, with increased rates in soils from the southern locations. Our results suggest that microorganisms in the driest soils of the Atacama Desert are in a state of stasis for most of the time, but can potentially metabolize if presented with liquid water for a sufficient duration. Over geological time, rare rain events and physicochemical factors potentially played a major role in selecting micro-organisms that are most adapted to extreme desiccating conditions.

  19. Microbial community composition and endolith colonization at an Arctic thermal spring are driven by calcite precipitation

    Science.gov (United States)

    Starke, Verena; Kirshtein, Julie; Fogel, Marilyn L.; Steele, Andrew

    2013-01-01

    Environmental conditions shape community composition. Arctic thermal springs provide an opportunity to study how environmental gradients can impose strong selective pressures on microbial communities and provide a continuum of niche opportunities. We use microscopic and molecular methods to conduct a survey of microbial community composition at Troll Springs on Svalbard, Norway, in the high Arctic. Microorganisms there exist under a wide range of environmental conditions: in warm water as periphyton, in moist granular materials, and in cold, dry rock as endoliths. Troll Springs has two distinct ecosystems, aquatic and terrestrial, together in close proximity, with different underlying environmental factors shaping each microbial community. Periphyton are entrapped during precipitation of calcium carbonate from the spring's waters, providing microbial populations that serve as precursors for the development of endolithic communities. This process differs from most endolith colonization, in which the rock predates the communities that colonize it. Community composition is modulated as environmental conditions change within the springs. At Troll, the aquatic environments show a small number of dominant operational taxonomic units (OTUs) that are specific to each sample. The terrestrial environments show a more even distribution of OTUs common to multiple samples.

  20. Variable effects of plant colonization on black slate uptake into microbial PLFAs

    Science.gov (United States)

    Seifert, Anne-Gret; Trumbore, Susan; Xu, Xiaomei; Zhang, Dachung; Gleixner, Gerd

    2013-04-01

    Microbial degradation of carbon derived from black shale and slate has been shown in vitro. However, in natural settings where other labile carbon sources are likely to exist, this has not been previously demonstrated. We investigated the uptake of ancient carbon derived from slate weathering and from recently photosynthesised organic matter by different groups of microorganisms. Therefore we isolated microbial biomarkers (phospholipid fatty acids, PLFAs) from black slates collected at a chronosequence of waste piles which differed in age and vegetation cover. We quantified the amount of PLFAs and performed stable isotope and radiocarbon measurements on individual or grouped PLFAs to quantify the fraction of slate derived carbon. We used black slate from a pile heaped in the 1950s with either uncovered black slate material (bare site) or material slightly colonized by small plants (greened site) and from a forested leaching pile (forested site) used for alum-mining in the 19th century. Colonization by plants influenced the amount and composition of the microbial community. Greater amounts of PLFAs (5410 ng PLFA/g dw) were extracted from slate sampled at the forested site as opposed to the bare site (960 ng PLFAs/g dw) or the greened (annual grasses and mosses) rock waste pile (1050 ng PLFAs/g dw). We found the highest proportion of PLFAs representing Gram-negative bacteria on the forested site and the highest proportion of PLFAs representing Gram-positive bacteria on the bare site. The fungal PLFA was most abundant at the greened site. Sites with less plant colonization (bare and greened site) tended to have more depleted δ13C values compared to the forested site. Radiocarbon measurements on PLFAs indicated that fungi and Gram-positive bacteria were best adapted to black slate carbon uptake. In the fungal PLFA (combined bare and greened waste pile sample) and in PLFAs of Gram-positive bacteria (greened site) we measured 39.7% and 28.9% ancient carbon uptake

  1. Microbial colonization of biopolymeric thin films containing natural compounds and antibiotics fabricated by MAPLE

    Energy Technology Data Exchange (ETDEWEB)

    Cristescu, R., E-mail: rodica.cristescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, PO Box MG-36, Bucharest-Magurele (Romania); Surdu, A.V.; Grumezescu, A.M.; Oprea, A.E.; Trusca, R.; Vasile, O. [Faculty of Applied Chemistry and Materials Science, Department of Science and Engineering of Oxide Materials and Nanomaterials, Politehnica University of Bucharest, Polizu Street No. 1–7, 011061 Bucharest (Romania); Dorcioman, G.; Visan, A.; Socol, G.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, PO Box MG-36, Bucharest-Magurele (Romania); Mihaiescu, D. [Faculty of Applied Chemistry and Materials Science, Department of Organic Chemistry, Politehnica University of Bucharest, 1–7 Polizu Street, 011061 Bucharest (Romania); Enculescu, M. [National Institute of Materials Physics, PO Box MG-7, Bucharest-Magurele (Romania); Chifiriuc, M.C. [Microbiology Immunology Department, Faculty of Biology, Research Institute of the University of Bucharest—ICUB, Research Institute of the University of Bucharest, 77206 Bucharest (Romania); Boehm, R.D.; Narayan, R.J. [Biomedical Engineering, University of North Carolina, Chapel Hill, NC (United States); Chrisey, D.B. [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA (United States)

    2015-05-01

    Highlights: • We deposited thin composite quercetin/polyvinylpyrrolidone/antibiotic films with close resemblance to the starting/drop-cast composition by MAPLE. • Quercetin flavonoid shows an anti-biofilm activity comparable to that of the tested large-spectrum antibiotics (norfloxacin or cefuroxime), especially in case of 72 h biofilms. • These results could account for the possible use of quercetin as an alternative to antibiotics to combat the mature biofilms developed on different substrates. • MAPLE may be used to produce implantable medical devices that provide a relatively long term in vitro stability and resistance to the growth of microorganisms. - Abstract: Although a great number of antibiotics are currently available, they are often rendered ineffective by the ability of microbial strains to develop genetic resistance and to grow in biofilms. Since many antimicrobial agents poorly penetrate biofilms, biofilm-associated infections often require high concentrations of antimicrobial agents for effective treatment. Among the various strategies that may be used to inhibit microbial biofilms, one strategy that has generated significant interest involves the use of bioactive surfaces that are resistant to microbial colonization. In this respect, we used matrix assisted pulsed laser evaporation (MAPLE) involving a pulsed KrF* excimer laser source (λ = 248 nm, τ = 25 ns, ν = 10 Hz) to obtain thin composite biopolymeric films containing natural (flavonoid) or synthetic (antibiotic) compounds as bioactive substances. Chemical composition and film structures were investigated by Fourier transform infrared spectroscopy and X-ray diffraction. Films morphology was studied by scanning electron microscopy and transmission electron microscopy. The antimicrobial assay of the microbial biofilms formed on these films was assessed by the viable cell counts method. The flavonoid-containing thin films showed increased resistance to microbial colonization

  2. Microbial colonization of biopolymeric thin films containing natural compounds and antibiotics fabricated by MAPLE

    International Nuclear Information System (INIS)

    Cristescu, R.; Surdu, A.V.; Grumezescu, A.M.; Oprea, A.E.; Trusca, R.; Vasile, O.; Dorcioman, G.; Visan, A.; Socol, G.; Mihailescu, I.N.; Mihaiescu, D.; Enculescu, M.; Chifiriuc, M.C.; Boehm, R.D.; Narayan, R.J.; Chrisey, D.B.

    2015-01-01

    Highlights: • We deposited thin composite quercetin/polyvinylpyrrolidone/antibiotic films with close resemblance to the starting/drop-cast composition by MAPLE. • Quercetin flavonoid shows an anti-biofilm activity comparable to that of the tested large-spectrum antibiotics (norfloxacin or cefuroxime), especially in case of 72 h biofilms. • These results could account for the possible use of quercetin as an alternative to antibiotics to combat the mature biofilms developed on different substrates. • MAPLE may be used to produce implantable medical devices that provide a relatively long term in vitro stability and resistance to the growth of microorganisms. - Abstract: Although a great number of antibiotics are currently available, they are often rendered ineffective by the ability of microbial strains to develop genetic resistance and to grow in biofilms. Since many antimicrobial agents poorly penetrate biofilms, biofilm-associated infections often require high concentrations of antimicrobial agents for effective treatment. Among the various strategies that may be used to inhibit microbial biofilms, one strategy that has generated significant interest involves the use of bioactive surfaces that are resistant to microbial colonization. In this respect, we used matrix assisted pulsed laser evaporation (MAPLE) involving a pulsed KrF* excimer laser source (λ = 248 nm, τ = 25 ns, ν = 10 Hz) to obtain thin composite biopolymeric films containing natural (flavonoid) or synthetic (antibiotic) compounds as bioactive substances. Chemical composition and film structures were investigated by Fourier transform infrared spectroscopy and X-ray diffraction. Films morphology was studied by scanning electron microscopy and transmission electron microscopy. The antimicrobial assay of the microbial biofilms formed on these films was assessed by the viable cell counts method. The flavonoid-containing thin films showed increased resistance to microbial colonization

  3. The First Microbial Colonizers of the Human Gut: Composition, Activities, and Health Implications of the Infant Gut Microbiota.

    Science.gov (United States)

    Milani, Christian; Duranti, Sabrina; Bottacini, Francesca; Casey, Eoghan; Turroni, Francesca; Mahony, Jennifer; Belzer, Clara; Delgado Palacio, Susana; Arboleya Montes, Silvia; Mancabelli, Leonardo; Lugli, Gabriele Andrea; Rodriguez, Juan Miguel; Bode, Lars; de Vos, Willem; Gueimonde, Miguel; Margolles, Abelardo; van Sinderen, Douwe; Ventura, Marco

    2017-12-01

    The human gut microbiota is engaged in multiple interactions affecting host health during the host's entire life span. Microbes colonize the neonatal gut immediately following birth. The establishment and interactive development of this early gut microbiota are believed to be (at least partially) driven and modulated by specific compounds present in human milk. It has been shown that certain genomes of infant gut commensals, in particular those of bifidobacterial species, are genetically adapted to utilize specific glycans of this human secretory fluid, thus representing a very intriguing example of host-microbe coevolution, where both partners are believed to benefit. In recent years, various metagenomic studies have tried to dissect the composition and functionality of the infant gut microbiome and to explore the distribution across the different ecological niches of the infant gut biogeography of the corresponding microbial consortia, including those corresponding to bacteria and viruses, in healthy and ill subjects. Such analyses have linked certain features of the microbiota/microbiome, such as reduced diversity or aberrant composition, to intestinal illnesses in infants or disease states that are manifested at later stages of life, including asthma, inflammatory bowel disease, and metabolic disorders. Thus, a growing number of studies have reported on how the early human gut microbiota composition/development may affect risk factors related to adult health conditions. This concept has fueled the development of strategies to shape the infant microbiota composition based on various functional food products. In this review, we describe the infant microbiota, the mechanisms that drive its establishment and composition, and how microbial consortia may be molded by natural or artificial interventions. Finally, we discuss the relevance of key microbial players of the infant gut microbiota, in particular bifidobacteria, with respect to their role in health and

  4. Evolutionary bottlenecks in brackish water habitats drive the colonization of fresh water by stingrays.

    Science.gov (United States)

    Kirchhoff, K N; Hauffe, T; Stelbrink, B; Albrecht, C; Wilke, T

    2017-08-01

    Species richness in freshwater bony fishes depends on two main processes: the transition into and the diversification within freshwater habitats. In contrast to bony fishes, only few cartilaginous fishes, mostly stingrays (Myliobatoidei), were able to colonize fresh water. Respective transition processes have been mainly assessed from a physiological and morphological perspective, indicating that the freshwater lifestyle is strongly limited by the ability to perform osmoregulatory adaptations. However, the transition history and the effect of physiological constraints on the diversification in stingrays remain poorly understood. Herein, we estimated the geographic pathways of freshwater colonization and inferred the mode of habitat transitions. Further, we assessed habitat-related speciation rates in a time-calibrated phylogenetic framework to understand factors driving the transition of stingrays into and the diversification within fresh water. Using South American and Southeast Asian freshwater taxa as model organisms, we found one independent freshwater colonization event by stingrays in South America and at least three in Southeast Asia. We revealed that vicariant processes most likely caused freshwater transition during the time of major marine incursions. The habitat transition rates indicate that brackish water species switch preferably back into marine than forth into freshwater habitats. Moreover, our results showed significantly lower diversification rates in brackish water lineages, whereas freshwater and marine lineages exhibit similar rates. Thus, brackish water habitats may have functioned as evolutionary bottlenecks for the colonization of fresh water by stingrays, probably because of the higher variability of environmental conditions in brackish water. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  5. Colonization Habitat Controls Biomass, Composition, and Metabolic Activity of Attached Microbial Communities in the Columbia River Hyporheic Corridor

    Energy Technology Data Exchange (ETDEWEB)

    Stern, Noah; Ginder-Vogel, Matthew; Stegen, James C.; Arntzen, Evan; Kennedy, David W.; Larget, Bret R.; Roden, Eric E.; Kostka, Joel E.

    2017-06-09

    Hydrologic exchange plays a critical role in biogeochemical cycling within the hyporheic zone (the interface between river water and groundwater) of riverine ecosystems. Such exchange may set limits on the rates of microbial metabolism and impose deterministic selection on microbial communities that adapt to dynamically changing dissolved organic carbon (DOC) sources. This study examined the response of attached microbial communities (in situcolonized sand packs) from groundwater, hyporheic, and riverbed habitats within the Columbia River hyporheic corridor to “cross-feeding” with either groundwater, river water, or DOC-free artificial fluids. Our working hypothesis was that deterministic selection duringin situcolonization would dictate the response to cross-feeding, with communities displaying maximal biomass and respiration when supplied with their native fluid source. In contrast to expectations, the major observation was that the riverbed colonized sand had much higher biomass and respiratory activity, as well as a distinct community structure, compared with those of the hyporheic and groundwater colonized sands. 16S rRNA gene amplicon sequencing revealed a much higher proportion of certain heterotrophic taxa as well as significant numbers of eukaryotic algal chloroplasts in the riverbed colonized sand. Significant quantities of DOC were released from riverbed sediment and colonized sand, and separate experiments showed that the released DOC stimulated respiration in the groundwater and piezometer colonized sand. These results suggest that the accumulation and degradation of labile particulate organic carbon (POC) within the riverbed are likely to release DOC, which may enter the hyporheic corridor during hydrologic exchange, thereby stimulating microbial activity and imposing deterministic selective pressure on the microbial community composition.

    IMPORTANCEThe influence of river water

  6. The Effect of Therapeutic Clowning on Handwashing Technique and Microbial Colonization in Preschool Children.

    Science.gov (United States)

    Arıkan, Duygu; Gürarslan Baş, Nazan; Kurudirek, Fatma; Baştopcu, Ayşe; Uslu, Hakan

    2018-05-15

    This study aimed to determine the effect of therapeutic clowning on handwashing technique and microbial colonization in preschool children. This randomized controlled trial was conducted using pre-test and post-test experimental and control groups. The study was conducted between March and June 2016 in two kindergartens in eastern Turkey. The study was completed with a total of 195 students, including 90 students in the experimental group and 105 students in the control group. A questionnaire was used for data collection. This questionnaire included sections about the subjects' descriptive characteristics and the results of the bacterial cultures of their hand swabs. For the collection of these swabs, the subjects were informed in advance, and samples were collected at predetermined times. The swabs were analyzed to determine the bacterial colonization of the subjects' hands. Clowns and video activities were used as intervention tools in the study. In the post-test, the microbial growth was ≤10 3 in 68.9% and >10 3 in 31.1% of the subjects in the experimental group. In contrast, the growth was ≤10 3 in 34.3% and >10 3 in 65.7% of the control group subjects. The difference in the post-test microbial growths of the two groups was statistically significant (p < .000). The hygienic handwashing technique taught in the therapeutic clowning and videos reduced the bacterial colonization on the preschool children's hands by 50%. Moreover, this method was effective in reducing the growth rate of coliform bacteria that indicate undesirable, poor hygiene of the hands. Considering these results, we recommend that pediatric healthcare professionals use entertaining methods such as those involving clowns to teach and guide children regarding hygienic handwashing techniques. © 2018 Sigma Theta Tau International.

  7. Characterization of microbial communities in pest colonized books by molecular biology tools

    Directory of Open Access Journals (Sweden)

    Franco Palla

    2011-08-01

    Full Text Available This work presents the identification of bacteria and fungi colonies in insect infesting books, by cultural-independent methodologies based on molecular biology techniques. Microbial genomic DNA extraction, in vitro amplification of specific target sequences by polymerase chain reactions (PCR, sequencing and sequence analysis were performed. These procedures minimized the samples amount, optimized the diagnostic studies on bacteria and fungi colonization and allowed the identification of many species also in complex microbial consortia. The molecular techniques for sure accomplish and integrate the microbiological standard methods (in vitro culture and morphological analyses (OM, SEM, CLSM, in order to understand the role of microorganisms in bio-deterioration of cultural assets. This monitoring is also indispensable to shed light on the risk for visitors and/or professionals to contract potential illnesses within indoor environments.

  8. The potential of whey in driving microbial fuel cells: A dual prospect ...

    African Journals Online (AJOL)

    Renewable and green energy resources are paramount to environmental sustainability. Microbial fuel cells (MFCs) are potential candidates for these alternatives but there is need to search for cheaper fuels to drive the MFCs for realistic large scale applications. A high strength effluent such as whey, which poses a serious ...

  9. Investigating microbial colonization in actively forming hydrothermal deposits using thermocouple arrays

    Science.gov (United States)

    Tivey, M. K.; Reysenbach, A. L.; Hirsch, M.; Steinberg, J.; Flores, G. E.

    2010-12-01

    Investigations of microbial colonization of very young hydrothermal deposits were carried out in 2009 at hydrothermal vents in the Lau Basin (SW Pacific), and in Guaymas Basin, Gulf of California, with a test deployment at the Rainbow vent field on the Mid-Atlantic Ridge in 2008. Our method entailed razing active chimneys and placing arrays of temperature probes (8 titanium-encased probes with their tips placed within a titanium cage) over the active flow. The chimneys that grew back through each array, encasing the temperature probe tips, were recovered after 2 to 15 days, along with temperature records. Molecular phylogenetic methods are being used to reveal the members of the microbial communities that developed in each chimney of known age and thermal history. A total of 15 array deployments were made at 10 vents in 6 different vent fields. Similar morphology beehives (with porous fine-grained interiors and steep temperature gradients across the outermost more-consolidated “wall”) formed at 2 of the 3 vents in Guaymas Basin (in 2 and 5 days at one vent and 3 and 15 days at a second), and at one vent each in the Kilo Moana (in 3 days), Tahi Moana (in 2.5 days), and Tui Malila (in 3 and 8 days) vent fields in the Lau Basin. In contrast, open conduit, thin walled chimneys grew within arrays at the Mariner vent field, Lau Basin, at 3 different vents (in 3 days at one vent, in 3 and 11 days at a second vent, and in 13 days at a third vent). A lower temperature (Archaea showed very little change in diversity over time, with members of the genera Thermococcus and Methanocaldococcus present in all samples analyzed, irrespective of location and timing of sampling. This is very different from a 72-hour test array deployment done in 2008 at Rainbow vent field, where the deposited soft material was colonized only by the sulfate-reducing archaeum, Archaeoglobus. These samples (8 beehives, 4 open conduit smokers, one diffuser spire, from chimneys of known composition

  10. Acetaldehyde production and microbial colonization in oral squamous cell carcinoma and oral lichenoid disease.

    Science.gov (United States)

    Marttila, Emilia; Uittamo, Johanna; Rusanen, Peter; Lindqvist, Christian; Salaspuro, Mikko; Rautemaa, Riina

    2013-07-01

    The main aim of this prospective study was to explore the ability of the oral microbiome to produce acetaldehyde in ethanol incubation. A total of 90 patients [30 oral squamous cell carcinoma (OSCC); 30 oral lichenoid disease (OLD); 30 healthy controls (CO)] were enrolled in the study. Microbial samples were taken from the mucosa using a filter paper method. The density of microbial colonization was calculated and the spectrum analyzed. Microbial acetaldehyde production was measured by gas chromatography. The majority (68%) of cultures produced carcinogenic levels of acetaldehyde (>100 μM) when incubated with ethanol (22 mM). The mean acetaldehyde production by microbes cultured from smoker samples was significantly higher (213 μM) than from non-smoker samples (141 μM) (P=.0326). The oral microbiota from OSCC, OLD patients and healthy individuals are able to produce carcinogenic levels of acetaldehyde. The present provisional study suggests smoking may increase the production of acetaldehyde. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Mineralogical controls on surface colonization by sulfur-metabolizing microbial communities

    Science.gov (United States)

    Jones, A. A.; Bennett, P.

    2012-12-01

    When characterizing microbial diversity and the microbial ecosystem of the shallow subsurface the mineral matrix is generally assumed to be homogenous and unreactive. We report here experimental evidence that microorganisms colonize rock surfaces according to the rock's chemistry and the organism's metabolic requirements and tolerances. We investigated this phenomenon using laboratory biofilm reactors with both a pure culture of sulfur-oxidizing Thiothrix unzii and a mixed environmental sulfur-metabolizing community from Lower Kane, Cave, WY, USA. Reactors contained rock and mineral chips (calcite, albite, microcline, quartz, chert, Madison Limestone (ML), Madison Dolostone (MD), and basalt) amended with one of the two inoculants. Biomass of attached microorganisms on each mineral surface was quantified. The 16S rRNA of attached microbial communities were compared using Roche FLX and Titanium 454 next generation pyrosequencing. A primary controlling factor on taxonomy of attached microorganisms in both pure and mixed culture experiments was mineral buffering capacity. In mixed culture experiments acid-buffering carbonates were preferentially colonized by neutrophilic sulfur-oxidizing microorganisms (~18% to ~27% of microorganisms), while acidophilic sulfur-oxidizing microorganisms colonized non-buffering quartz exclusively (~46% of microorganisms). The nutrient content of the rock was a controlling factor on biomass accumulation, with neutrophilic organisms selecting between carbonate surfaces of equivalent buffer capacities according to the availability of phosphate. Dry biomass on ML was 17.8 ± 2.3 mg/cm2 and MD was 20.6 ± 6.8 mg/cm2; while nutrient poor calcite accumulated 2.4 ± 0.3 mg/cm2. Biomass accumulation was minimal on non-buffering nutrient-limited surfaces. These factors are countered by the competitive exclusion of some populations. A pure culture of T. unzii preferentially colonizes carbonates while a very closely related Thiothrix spp is excluded

  12. Steam explosion enhances digestibility and fermentation of corn stover by facilitating ruminal microbial colonization.

    Science.gov (United States)

    Zhao, Shengguo; Li, Guodong; Zheng, Nan; Wang, Jiaqi; Yu, Zhongtang

    2018-04-01

    The purpose of this study was to evaluate steam explosion as a pretreatment to enhance degradation of corn stover by ruminal microbiome. The steam explosion conditions were first optimized, and then the efficacy of steam explosion was evaluated both in vitro and in vivo. Steam explosion altered the physical and chemical structure of corn stover as revealed by scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy, respectively, and increased its cellulose content while decreasing hemicellulose content. Steam-exploded corn stover also increased release of reducing sugars, rate of fermentation, and production of volatile fatty acids (VFAs) in vitro. The steam explosion treatment increased microbial colonization and in situ degradation of cellulose and hemicellulose of corn stover in the rumen of dairy cows. Steam explosion may be a useful pretreatment of corn stover to improve its nutritional value as forage for cattle, or as feedstock for biofuel production. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota

    Science.gov (United States)

    Marteinsson, V.; Klonowski, A.; Reynisson, E.; Vannier, P.; Sigurdsson, B. D.; Ólafsson, M.

    2015-02-01

    Colonization of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue-green algae, most studies have been focused on the settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse soils and the influence of associated vegetation and birds on numbers of environmental bacteria, we collected 45 samples from different soil types on the surface of the island. Total viable bacterial counts were performed with the plate count method at 22, 30 and 37 °C for all soil samples, and the amount of organic matter and nitrogen (N) was measured. Selected samples were also tested for coliforms, faecal coliforms and aerobic and anaerobic bacteria. The subsurface biosphere was investigated by collecting liquid subsurface samples from a 181 m borehole with a special sampler. Diversity analysis of uncultivated biota in samples was performed by 16S rRNA gene sequences analysis and cultivation. Correlation was observed between nutrient deficits and the number of microorganisms in surface soil samples. The lowest number of bacteria (1 × 104-1 × 105 cells g-1) was detected in almost pure pumice but the count was significantly higher (1 × 106-1 × 109 cells g-1) in vegetated soil or pumice with bird droppings. The number of faecal bacteria correlated also to the total number of bacteria and type of soil. Bacteria belonging to Enterobacteriaceae were only detected in vegetated samples and samples containing bird droppings. The human pathogens Salmonella, Campylobacter and Listeria were not in any sample. Both thermophilic bacteria and archaea 16S rDNA sequences were found in the subsurface samples collected at 145 and 172 m depth at 80 and 54 °C, respectively, but no growth was observed in enrichments. The microbiota sequences generally showed low affiliation to any known 16S rRNA gene sequences.

  14. Nanocoatings for Chronic Wound Repair—Modulation of Microbial Colonization and Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Mara Mădălina Mihai

    2018-04-01

    Full Text Available Wound healing involves a complex interaction between immunity and other natural host processes, and to succeed it requires a well-defined cascade of events. Chronic wound infections can be mono- or polymicrobial but their major characteristic is their ability to develop a biofilm. A biofilm reduces the effectiveness of treatment and increases resistance. A biofilm is an ecosystem on its own, enabling the bacteria and the host to establish different social interactions, such as competition or cooperation. With an increasing incidence of chronic wounds and, implicitly, of chronic biofilm infections, there is a need for alternative therapeutic agents. Nanotechnology shows promising openings, either by the intrinsic antimicrobial properties of nanoparticles or their function as drug carriers. Nanoparticles and nanostructured coatings can be active at low concentrations toward a large variety of infectious agents; thus, they are unlikely to elicit emergence of resistance. Nanoparticles might contribute to the modulation of microbial colonization and biofilm formation in wounds. This comprehensive review comprises the pathogenesis of chronic wounds, the role of chronic wound colonization and infection in the healing process, the conventional and alternative topical therapeutic approaches designed to combat infection and stimulate healing, as well as revolutionizing therapies such as nanotechnology-based wound healing approaches.

  15. Microbial ecology of fermentative hydrogen producing bioprocesses: useful insights for driving the ecosystem function.

    Science.gov (United States)

    Cabrol, Lea; Marone, Antonella; Tapia-Venegas, Estela; Steyer, Jean-Philippe; Ruiz-Filippi, Gonzalo; Trably, Eric

    2017-03-01

    One of the most important biotechnological challenges is to develop environment friendly technologies to produce new sources of energy. Microbial production of biohydrogen through dark fermentation, by conversion of residual biomass, is an attractive solution for short-term development of bioH2 producing processes. Efficient biohydrogen production relies on complex mixed communities working in tight interaction. Species composition and functional traits are of crucial importance to maintain the ecosystem service. The analysis of microbial community revealed a wide phylogenetic diversity that contributes in different-and still mostly unclear-ways to hydrogen production. Bridging this gap of knowledge between microbial ecology features and ecosystem functionality is essential to optimize the bioprocess and develop strategies toward a maximization of the efficiency and stability of substrate conversion. The aim of this review is to provide a comprehensive overview of the most up-to-date biodata available and discuss the main microbial community features of biohydrogen engineered ecosystems, with a special emphasis on the crucial role of interactions and the relationships between species composition and ecosystem service. The elucidation of intricate relationships between community structure and ecosystem function would make possible to drive ecosystems toward an improved functionality on the basis of microbial ecology principles. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Rhizosphere effect of colonizer plant species on the development of soil microbial community during primary succession on postmining sites

    Energy Technology Data Exchange (ETDEWEB)

    Elhottova, D.; Kristufek, V.; Maly, S.; Frouz, J. [Academy of Sciences of the Czech Republic, Ceske Budejovice (Czech Republic). Inst. for Soil Biology

    2009-07-01

    The impact of pioneer plant species Tussilago farfara on structural, functional, and growth characterization of microbial community colonizing the spoil colliery substrate was studied in a laboratory microcosm experiment. Microcosms consisting of spoil substrate (0.7 dm{sup 3} of tertiary alkaline clay sediment from Sokolov brown-coal mine area) from a pioneer site (without vegetation, 5 years after heaping) were cultivated in a greenhouse with one plant of this species. Plant roots substantially increased microbial diversity and biomass after one season (7 months) of cultivation. Roots influenced the microbial community and had nearly twice the size, higher growth, and metabolic potential in comparison to the control. The development of microbial specialists improves the plant nutrient status. Bacterial nitrogen (N{sub 2}) fixators (Bradyrhizobium japonicum, Rhizobium radiobacter) and arbuscular mycorrhizal fungi were confirmed in the rhizosphere of Tussilago farfara.

  17. Effects of silver sulfide nanomaterials on mycorrhizal colonization of tomato plants and soil microbial communities in biosolid-amended soil

    International Nuclear Information System (INIS)

    Judy, Jonathan D.; Kirby, Jason K.; Creamer, Courtney; McLaughlin, Mike J.; Fiebiger, Cathy; Wright, Claire; Cavagnaro, Timothy R.; Bertsch, Paul M.

    2015-01-01

    We investigated effects of Ag_2S engineered nanomaterials (ENMs), polyvinylpyrrolidone (PVP) coated Ag ENMs (PVP-Ag), and Ag"+ on arbuscular mycorrhizal fungi (AMF), their colonization of tomato (Solanum lycopersicum), and overall microbial community structure in biosolids-amended soil. Concentration-dependent uptake was measured in all treatments. Plants exposed to 100 mg kg"−"1 PVP-Ag ENMs and 100 mg kg"−"1 Ag"+ exhibited reduced biomass and greatly reduced mycorrhizal colonization. Bacteria, actinomycetes and fungi were inhibited by all treatment classes, with the largest reductions measured in 100 mg kg"−"1 PVP-Ag ENMs and 100 mg kg"−"1 Ag"+. Overall, Ag_2S ENMs were less toxic to plants, less disruptive to plant-mycorrhizal symbiosis, and less inhibitory to the soil microbial community than PVP-Ag ENMs or Ag"+. However, significant effects were observed at 1 mg kg"−"1 Ag_2S ENMs, suggesting that the potential exists for microbial communities and the ecosystem services they provide to be disrupted by environmentally relevant concentrations of Ag_2S ENMs. - Highlights: • PVP-Ag and Ag"+ inhibited AMF colonization more readily than Ag_2S ENMs. • Impact of PVP-Ag ENMs and Ag"+ on microbial communities larger than for Ag_2S ENMs. • Significant changes in microbial communities in response to Ag_2S ENMs at 1 mg kg"−"1. - Although Ag_2S ENMs are less toxic to soil microorganisms than pristine nanomaterials or ions, some effects are observed on soil microbial communities at relevant concentrations.

  18. Diet, microbiota, and microbial metabolites in colon cancer risk in rural Africans and African Americans

    NARCIS (Netherlands)

    Ou, J.; Carbonero, F.; Zoetendal, E.G.; Delany, J.P.; Wang, M.; Newton, K.; Gaskins, H.R.; O'Keefe, S.F.

    2013-01-01

    BACKGROUND: Epidemiologic studies have suggested that most cases of sporadic colon cancer can be attributed to diet. The recognition that colonic microbiota have a major influence on colonic health suggests that they might mediate colonic carcinogenesis. OBJECTIVE: To examine the hypothesis that the

  19. Electron acceptors for anaerobic oxidation of methane drive microbial community structure and diversity in mud volcanoes.

    Science.gov (United States)

    Ren, Ge; Ma, Anzhou; Zhang, Yanfen; Deng, Ye; Zheng, Guodong; Zhuang, Xuliang; Zhuang, Guoqiang; Fortin, Danielle

    2018-04-06

    Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high-throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate- and iron-reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM). The impacts of sulfate/iron/nitrate on AOM in the MVs were verified by microcosm experiments. Further, two representative MVs were selected to explore the microbial interactions based on phylogenetic molecular ecological networks. The sites showed distinct network structures, key species and microbial interactions, with more complex and numerous linkages between methane-cycling microbes and their partners being observed in the iron/sulfate-rich MV. These findings suggest that electron acceptors are important factors driving the structure of microbial communities in these methane-rich environments. © 2018 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  20. Microbial colonization and degradation of polyethylene and biodegradable plastic bags in temperate fine-grained organic-rich marine sediments.

    Science.gov (United States)

    Nauendorf, Alice; Krause, Stefan; Bigalke, Nikolaus K; Gorb, Elena V; Gorb, Stanislav N; Haeckel, Matthias; Wahl, Martin; Treude, Tina

    2016-02-15

    To date, the longevity of plastic litter at the sea floor is poorly constrained. The present study compares colonization and biodegradation of plastic bags by aerobic and anaerobic benthic microbes in temperate fine-grained organic-rich marine sediments. Samples of polyethylene and biodegradable plastic carrier bags were incubated in natural oxic and anoxic sediments from Eckernförde Bay (Western Baltic Sea) for 98 days. Analyses included (1) microbial colonization rates on the bags, (2) examination of the surface structure, wettability, and chemistry, and (3) mass loss of the samples during incubation. On average, biodegradable plastic bags were colonized five times higher by aerobic and eight times higher by anaerobic microbes than polyethylene bags. Both types of bags showed no sign of biodegradation during this study. Therefore, marine sediment in temperate coastal zones may represent a long-term sink for plastic litter and also supposedly compostable material. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Evaluation of the Efficacy of Different Mixing Techniques and Disinfection on Microbial Colonization of Polyether Impression Materials: A Comparative Study.

    Science.gov (United States)

    Singla, Youginder; Pachar, Renu B; Poriya, Sangeeta; Mishra, Aalok; Sharma, Rajni; Garg, Anshu

    2018-03-01

    This study aims to determine the role of mixing techniques of polyether impression materials and efficacy of disinfection on microbial colonization of these impression materials. Polyether impression material was mixed using two methods: First by hand mixing (group I) and second using an automixer (group II) with a total of 100 samples. Four microbial strains were studied, which included Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. After incubation, the bacterial colonies were counted, and then, disinfectant solution was applied. The effect of disinfection solution was evaluated for each specimen. The surface of polyether impression materials mixed with an automixer has less number of voids and overall a smoother surface as compared with the hand-mixed ones. On comparing the disinfection procedures, i.e., specimens without any disinfection and specimens after disinfection, statistically highly significant difference was seen between all the groups. We can conclude that impression mixing procedures are important in determining the surface characteristics of the impression and ultimately the colonization of bacteria and also determine the importance of disinfection on microbial colonization. This study emphasises the deleterious role of nosocomial infections and specific measures that should be taken regarding the prevention of such diseases. Dental impressions are proved to be a source of such infections and may lead to transmission of such diseases. Thus, proper measures should be taken right from the first step of impression taking to minimizing and preventing such kind of contaminations in clinical practice.

  2. A central venous catheter coated with benzalkonium chloride for the prevention of catheter-related microbial colonization.

    Science.gov (United States)

    Moss, H A; Tebbs, S E; Faroqui, M H; Herbst, T; Isaac, J L; Brown, J; Elliott, T S

    2000-11-01

    In an attempt to overcome infections associated with central venous catheters, a new antiseptic central venous catheter coated with benzalkonium chloride on the internal and external surfaces has been developed and evaluated in a clinical trial. Patients (235) randomly received either a triple-lumen central venous catheter coated with benzalkonium chloride (117) or a polyurethane non-antiseptic catheter (118). The incidence of microbial colonization of both catheters and retained antiseptic activity of the benzalkonium chloride device following removal were determined. The benzalkonium chloride resulted in a significant reduction of the incidence of microbial colonization on both the internal and external catheter surfaces. The reduction in colonization was detected at both the intradermal (21 benzalkonium chloride catheters vs. 38 controls, P = 0.0016) and distal segments of the antiseptic-coated catheters. Following catheter removal retained activity was demonstrated in benzalkonium chloride catheters which had been in place for up to 12 days. No patients developed adverse reactions to the benzalkonium chloride catheters. The findings demonstrate that the benzalkonium chloride catheter significantly reduced the incidence of catheter-associated colonization.

  3. Gut Microbial Metabolism of Polyphenols from Black Tea and Red Wine/Grape Juice Is Source-Specific and Colon-Region Dependent

    NARCIS (Netherlands)

    Dorsten, van F.A.; Peters, S.; Gross, G.; Gomez-Roldan, V.; Klinkenberg, M.; Vos, de Ric; Vaughan, E.E.; Duynhoven, van J.P.M.; Possemiers, S.; Wiele, van der T.; Jacobs, D.M.

    2012-01-01

    The colonic microbial degradation of a polyphenol-rich black tea extract (BTE) and red wine/grape juice extract (RWGE) was compared in a five-stage in vitro gastrointestinal model (TWINSHIME). Microbial metabolism of BTE and RWGE polyphenols in the TWINSHIME was studied subsequently in single- and

  4. Microbial community development in a dynamic gut model is reproducible, colon region specific, and selective for Bacteroidetes and Clostridium cluster IX

    NARCIS (Netherlands)

    Abbeele, van den P.; Grootaert, C.; Marzorati, M.; Possemiers, S.; Verstraete, W.; Gérard, P.; Rabot, S.; Bruneau, A.; Aidy, El S.F.; Derrien, M.M.N.; Zoetendal, E.G.; Kleerebezem, M.; Smidt, H.; Wiele, van der T.

    2010-01-01

    Dynamic, multicompartment in vitro gastrointestinal simulators are often used to monitor gut microbial dynamics and activity. These reactors need to harbor a microbial community that is stable upon inoculation, colon region specific, and relevant to in vivo conditions. Together with the

  5. Microbial community development in a dynamic gut model is reproducible, colon region specific, and selective for Bacteroidetes and Clostridium cluster IX.

    Science.gov (United States)

    Van den Abbeele, Pieter; Grootaert, Charlotte; Marzorati, Massimo; Possemiers, Sam; Verstraete, Willy; Gérard, Philippe; Rabot, Sylvie; Bruneau, Aurélia; El Aidy, Sahar; Derrien, Muriel; Zoetendal, Erwin; Kleerebezem, Michiel; Smidt, Hauke; Van de Wiele, Tom

    2010-08-01

    Dynamic, multicompartment in vitro gastrointestinal simulators are often used to monitor gut microbial dynamics and activity. These reactors need to harbor a microbial community that is stable upon inoculation, colon region specific, and relevant to in vivo conditions. Together with the reproducibility of the colonization process, these criteria are often overlooked when the modulatory properties from different treatments are compared. We therefore investigated the microbial colonization process in two identical simulators of the human intestinal microbial ecosystem (SHIME), simultaneously inoculated with the same human fecal microbiota with a high-resolution phylogenetic microarray: the human intestinal tract chip (HITChip). Following inoculation of the in vitro colon compartments, microbial community composition reached steady state after 2 weeks, whereas 3 weeks were required to reach functional stability. This dynamic colonization process was reproducible in both SHIME units and resulted in highly diverse microbial communities which were colon region specific, with the proximal regions harboring saccharolytic microbes (e.g., Bacteroides spp. and Eubacterium spp.) and the distal regions harboring mucin-degrading microbes (e.g., Akkermansia spp.). Importantly, the shift from an in vivo to an in vitro environment resulted in an increased Bacteroidetes/Firmicutes ratio, whereas Clostridium cluster IX (propionate producers) was enriched compared to clusters IV and XIVa (butyrate producers). This was supported by proportionally higher in vitro propionate concentrations. In conclusion, high-resolution analysis of in vitro-cultured gut microbiota offers new insight on the microbial colonization process and indicates the importance of digestive parameters that may be crucial in the development of new in vitro models.

  6. Seasonal differences in extinction and colonization drive occupancy dynamics of an imperilled amphibian.

    Directory of Open Access Journals (Sweden)

    Lea A Randall

    Full Text Available A detailed understanding of the population dynamics of many amphibian species is lacking despite concerns about declining amphibian biodiversity and abundance. This paper explores temporal patterns of occupancy and underlying extinction and colonization dynamics in a regionally imperiled amphibian species, the Northern leopard frog (Lithobates pipiens in Alberta. Our study contributes to elucidating regional occupancy dynamics at northern latitudes, where climate extremes likely have a profound effect on seasonal occupancy. The primary advantage of our study is its wide geographic scale (60,000 km2 and the use of repeat visual surveys each spring and summer from 2009-2013. We find that occupancy varied more dramatically between seasons than years, with low spring and higher summer occupancy. Between spring and summer, colonization was high and extinction low; inversely, colonization was low and extinction high over the winter. The dynamics of extinction and colonization are complex, making conservation management challenging. Our results reveal that Northern leopard frog occupancy was constant over the last five years and thus there is no evidence of decline or recovery within our study area. Changes to equilibrium occupancy are most sensitive to increasing colonization in the spring or declining extinction in the summer. Therefore, conservation and management efforts should target actions that are likely to increase spring colonization; this could be achieved through translocations or improving the quality or access to breeding habitat. Because summer occupancy is already high, it may be difficult to improve further. Nevertheless, summer extinction could be reduced by predator control, increasing water quality or hydroperiod of wetlands, or increasing the quality or quantity of summer habitat.

  7. Seasonal differences in extinction and colonization drive occupancy dynamics of an imperilled amphibian.

    Science.gov (United States)

    Randall, Lea A; Smith, Des H V; Jones, Breana L; Prescott, David R C; Moehrenschlager, Axel

    2015-01-01

    A detailed understanding of the population dynamics of many amphibian species is lacking despite concerns about declining amphibian biodiversity and abundance. This paper explores temporal patterns of occupancy and underlying extinction and colonization dynamics in a regionally imperiled amphibian species, the Northern leopard frog (Lithobates pipiens) in Alberta. Our study contributes to elucidating regional occupancy dynamics at northern latitudes, where climate extremes likely have a profound effect on seasonal occupancy. The primary advantage of our study is its wide geographic scale (60,000 km2) and the use of repeat visual surveys each spring and summer from 2009-2013. We find that occupancy varied more dramatically between seasons than years, with low spring and higher summer occupancy. Between spring and summer, colonization was high and extinction low; inversely, colonization was low and extinction high over the winter. The dynamics of extinction and colonization are complex, making conservation management challenging. Our results reveal that Northern leopard frog occupancy was constant over the last five years and thus there is no evidence of decline or recovery within our study area. Changes to equilibrium occupancy are most sensitive to increasing colonization in the spring or declining extinction in the summer. Therefore, conservation and management efforts should target actions that are likely to increase spring colonization; this could be achieved through translocations or improving the quality or access to breeding habitat. Because summer occupancy is already high, it may be difficult to improve further. Nevertheless, summer extinction could be reduced by predator control, increasing water quality or hydroperiod of wetlands, or increasing the quality or quantity of summer habitat.

  8. The influence of Staphylococcus aureus on gut microbial ecology in an in vitro continuous culture human colonic model system.

    Science.gov (United States)

    Sannasiddappa, Thippeswamy H; Costabile, Adele; Gibson, Glenn R; Clarke, Simon R

    2011-01-01

    An anaerobic three-stage continuous culture model of the human colon (gut model), which represent different anatomical areas of the large intestine, was used to study the effect of S. aureus infection of the gut on the resident faecal microbiota. Studies on the development of the microbiota in the three vessels were performed and bacteria identified by culture independent fluorescence in situ hybridization (FISH). Furthermore, short chain fatty acids (SCFA), as principal end products of gut bacterial metabolism, were measured along with a quantitative assessment of the predominant microbiota. During steady state conditions, numbers of S. aureus cells stabilised until they were washed out, but populations of indigenous bacteria were transiently altered; thus S. aureus was able to compromise colonisation resistance by the colonic microbiota. Furthermore, the concentration of butyric acid in the vessel representing the proximal colon was significantly decreased by infection. Thus infection by S. aureus appears to be able to alter the overall structure of the human colonic microbiota and the microbial metabolic profiles. This work provides an initial in vitro model to analyse interactions with pathogens.

  9. Intestinal helminth infection drives carcinogenesis in colitis-associated colon cancer.

    Directory of Open Access Journals (Sweden)

    Eva Pastille

    2017-09-01

    Full Text Available Inflammatory bowel diseases (IBD are chronic inflammatory disorders of the gastrointestinal tract, strongly associated with an increased risk of colorectal cancer development. Parasitic infections caused by helminths have been shown to modulate the host's immune response by releasing immunomodulatory molecules and inducing regulatory T cells (Tregs. This immunosuppressive state provoked in the host has been considered as a novel and promising approach to treat IBD patients and alleviate acute intestinal inflammation. On the contrary, specific parasite infections are well known to be directly linked to carcinogenesis. Whether a helminth infection interferes with the development of colitis-associated colon cancer (CAC is not yet known. In the present study, we demonstrate that the treatment of mice with the intestinal helminth Heligmosomoides polygyrus at the onset of tumor progression in a mouse model of CAC does not alter tumor growth and distribution. In contrast, H. polygyrus infection in the early inflammatory phase of CAC strengthens the inflammatory response and significantly boosts tumor development. Here, H. polygyrus infection was accompanied by long-lasting alterations in the colonic immune cell compartment, with reduced frequencies of colonic CD8+ effector T cells. Moreover, H. polygyrus infection in the course of dextran sulfate sodium (DSS mediated colitis significantly exacerbates intestinal inflammation by amplifying the release of colonic IL-6 and CXCL1. Thus, our findings indicate that the therapeutic application of helminths during CAC might have tumor-promoting effects and therefore should be well-considered.

  10. From vineyard to winery: a source map of microbial diversity driving wine fermentation.

    Science.gov (United States)

    Morrison-Whittle, Peter; Goddard, Matthew R

    2018-01-01

    Humans have been making wine for thousands of years and microorganisms play an integral part in this process as they not only drive fermentation, but also significantly influence the flavour, aroma and quality of finished wines. Since fruits are ephemeral, they cannot comprise a permanent microbial habitat; thus, an age-old unanswered question concerns the origin of fruit and ferment associated microbes. Here we use next-generation sequencing approaches to examine and quantify the roles of native forest, vineyard soil, bark and fruit habitats as sources of fungal diversity in ferments. We show that microbial communities in harvested juice and ferments vary significantly across regions, and that while vineyard fungi account for ∼40% of the source of this diversity, uncultivated ecosystems outside of vineyards also prove a significant source. We also show that while communities in harvested juice resemble those found on grapes, these increasingly resemble fungi present on vine bark as the ferment proceeds. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. Effect of Bioprocessing on the In Vitro Colonic Microbial Metabolism of Phenolic Acids from Rye Bran Fortified Breads

    DEFF Research Database (Denmark)

    Koistinen, Ville M; Nordlund, Emilia; Katina, Kati

    2017-01-01

    in an in vitro colon model, the metabolites were analyzed using two different methods applying mass spectrometry. While phenolic acids were released more extensively from the bioprocessed bran bread and ferulic acid had consistently higher concentrations in the bread type during fermentation, there were only......Cereal bran is an important source of dietary fiber and bioactive compounds, such as phenolic acids. We aimed to study the phenolic acid metabolism of native and bioprocessed rye bran fortified refined wheat bread and to elucidate the microbial metabolic route of phenolic acids. After incubation...

  12. Mammalian engineers drive soil microbial communities and ecosystem functions across a disturbance gradient.

    Science.gov (United States)

    Eldridge, David J; Delgado-Baquerizo, Manuel; Woodhouse, Jason N; Neilan, Brett A

    2016-11-01

    The effects of mammalian ecosystem engineers on soil microbial communities and ecosystem functions in terrestrial ecosystems are poorly known. Disturbance from livestock has been widely reported to reduce soil function, but disturbance by animals that forage in the soil may partially offset these negative effects of livestock, directly and/or indirectly by shifting the composition and diversity of soil microbial communities. Understanding the role of disturbance from livestock and ecosystem engineers in driving soil microbes and functions is essential for formulating sustainable ecosystem management and conservation policies. We compared soil bacterial community composition and enzyme concentrations within four microsites: foraging pits of two vertebrates, the indigenous short-beaked echidna (Tachyglossus aculeatus) and the exotic European rabbit (Oryctolagus cuniculus), and surface and subsurface soils along a gradient in grazing-induced disturbance in an arid woodland. Microbial community composition varied little across the disturbance gradient, but there were substantial differences among the four microsites. Echidna pits supported a lower relative abundance of Acidobacteria and Cyanobacteria, but a higher relative abundance of Proteobacteria than rabbit pits and surface microsites. Moreover, these microsite differences varied with disturbance. Rabbit pits had a similar profile to the subsoil or the surface soils under moderate and high, but not low disturbance. Overall, echidna foraging pits had the greatest positive effect on function, assessed as mean enzyme concentrations, but rabbits had the least. The positive effects of echidna foraging on function were indirectly driven via microbial community composition. In particular, increasing activity was positively associated with increasing relative abundance of Proteobacteria, but decreasing Acidobacteria. Our study suggests that soil disturbance by animals may offset, to some degree, the oft-reported negative

  13. The effect of microbial colonization on the host proteome varies by gastrointestinal location.

    Science.gov (United States)

    Lichtman, Joshua S; Alsentzer, Emily; Jaffe, Mia; Sprockett, Daniel; Masutani, Evan; Ikwa, Elvis; Fragiadakis, Gabriela K; Clifford, David; Huang, Bevan Emma; Sonnenburg, Justin L; Huang, Kerwyn Casey; Elias, Joshua E

    2016-05-01

    Endogenous intestinal microbiota have wide-ranging and largely uncharacterized effects on host physiology. Here, we used reverse-phase liquid chromatography-coupled tandem mass spectrometry to define the mouse intestinal proteome in the stomach, jejunum, ileum, cecum and proximal colon under three colonization states: germ-free (GF), monocolonized with Bacteroides thetaiotaomicron and conventionally raised (CR). Our analysis revealed distinct proteomic abundance profiles along the gastrointestinal (GI) tract. Unsupervised clustering showed that host protein abundance primarily depended on GI location rather than colonization state and specific proteins and functions that defined these locations were identified by random forest classifications. K-means clustering of protein abundance across locations revealed substantial differences in host protein production between CR mice relative to GF and monocolonized mice. Finally, comparison with fecal proteomic data sets suggested that the identities of stool proteins are not biased to any region of the GI tract, but are substantially impacted by the microbiota in the distal colon.

  14. An in vitro evaluation of antioxidant and colonic microbial profile levels following mushroom consumption.

    Science.gov (United States)

    Vamanu, Emanuel; Pelinescu, Diana; Avram, Ionela; Nita, Sultana

    2013-01-01

    The biological activity of mushroom consumption is achieved by the antioxidant effect of constituent biomolecules released during digestion. In the following study, the consumption of mushroom fungi was determined to increase the number of Lactobacillus and Bifidobacterium strains within the colon. The main phenolic antioxidant compounds identified were both gentisic and homogentisic acids. Moreover, the flavonoid catechin as well as a significant amount of δ - and γ-tocopherols was determined. The amount of Lactobacillus and Bifidobacterium strains from different sections of the human colon was significantly correlated with levels of antioxidative biomolecules. The experimental data clearly demonstrate a significant impact of mushroom consumption on the fermentative function of microorganisms in the human colon, resulting in the homeostasis of normal physiological colonic functions.

  15. Membrane biofouling in a wastewater nitrification reactor: microbial succession from autotrophic colonization to heterotrophic domination

    KAUST Repository

    Lu, Huijie; Xue, Zheng; Saikaly, Pascal; Nunes, Suzana Pereira; Bluver, Ted R.; Liu, Wen-Tso

    2015-01-01

    through significant changes. Initial colonizers were replaced by fast-growing and metabolically versatile heterotrophs (e.g., unclassified Sphingobacteria). The declining EPS polysaccharide to protein (PS:PN) ratios could be correlated well

  16. Deteriorating effects of lichen and microbial colonization of carbonate building rocks in the Romanesque churches of Segovia (Spain)

    International Nuclear Information System (INIS)

    Rios, Asuncion de los; Camara, Beatriz; Garcia del Cura, Ma Angeles; Rico, Victor J.; Galvan, Virginia; Ascaso, Carmen

    2009-01-01

    In this study, the deterioration effects of lichens and other lithobionts in a temperate mesothermal climate were explored. We examined samples of dolostone and limestone rocks with visible signs of biodeterioration taken from the exterior wall surfaces of four Romanesque churches in Segovia (Spain): San Lorenzo, San Martin, San Millan and La Vera Cruz. Biofilms developing on the lithic substrate were analyzed by scanning electron microscopy. The most common lichen species found in the samples were recorded. Fungal cultures were then obtained from these carbonate rocks and characterized by sequencing Internal Transcribed Spacers (ITS). Through scanning electron microscopy in back-scattered electron mode, fungi (lichenized and non-lichenized) were observed as the most frequent microorganisms occurring at sites showing signs of biodeterioration. The colonization process was especially conditioned by the porosity characteristics of the stone used in these buildings. While in dolostones, microorganisms mainly occupied spaces comprising the rock's intercrystalline porosity, in bioclastic dolomitized limestones, fungal colonization seemed to be more associated with moldic porosity. Microbial biofilms make close contact with the substrate, and thus probably cause significant deterioration of the underlying materials. We describe the different processes of stone alteration induced by fungal colonization and discuss the implications of these processes for the design of treatments to prevent biodeterioration

  17. Deteriorating effects of lichen and microbial colonization of carbonate building rocks in the Romanesque churches of Segovia (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Asuncion de los [Instituto de Recursos Naturales, Centro de Ciencias Medioambientales (CSIC), Serrano 115 dpdo., 28006 Madrid (Spain)], E-mail: arios@ccma.csic.es; Camara, Beatriz [Instituto de Recursos Naturales, Centro de Ciencias Medioambientales (CSIC), Serrano 115 dpdo., 28006 Madrid (Spain); Garcia del Cura, Ma Angeles [Instituto de Geologia Economica CSIC-UCM, Laboratorio de Petrologia Aplicada, Unidad Asociada CSIC-UA, Alicante (Spain); Rico, Victor J. [Departamento de Biologia Vegetal II, Facultad de Farmacia, Universidad Complutense, 28040 Madrid (Spain); Galvan, Virginia [Facultad Patrimonio Cultural, Universidad SEK, Convento de Santa Cruz la Real, 40003 Segovia (Spain); Ascaso, Carmen [Instituto de Recursos Naturales, Centro de Ciencias Medioambientales (CSIC), Serrano 115 dpdo., 28006 Madrid (Spain)

    2009-01-15

    In this study, the deterioration effects of lichens and other lithobionts in a temperate mesothermal climate were explored. We examined samples of dolostone and limestone rocks with visible signs of biodeterioration taken from the exterior wall surfaces of four Romanesque churches in Segovia (Spain): San Lorenzo, San Martin, San Millan and La Vera Cruz. Biofilms developing on the lithic substrate were analyzed by scanning electron microscopy. The most common lichen species found in the samples were recorded. Fungal cultures were then obtained from these carbonate rocks and characterized by sequencing Internal Transcribed Spacers (ITS). Through scanning electron microscopy in back-scattered electron mode, fungi (lichenized and non-lichenized) were observed as the most frequent microorganisms occurring at sites showing signs of biodeterioration. The colonization process was especially conditioned by the porosity characteristics of the stone used in these buildings. While in dolostones, microorganisms mainly occupied spaces comprising the rock's intercrystalline porosity, in bioclastic dolomitized limestones, fungal colonization seemed to be more associated with moldic porosity. Microbial biofilms make close contact with the substrate, and thus probably cause significant deterioration of the underlying materials. We describe the different processes of stone alteration induced by fungal colonization and discuss the implications of these processes for the design of treatments to prevent biodeterioration.

  18. Characterization of microbial metabolism of Syrah grape products in an in vitro colon model using targeted and non-targeted analytical approaches

    OpenAIRE

    Aura, Anna-Marja; Mattila, Ismo; Hyötyläinen, Tuulia; Gopalacharyulu, Peddinti; Cheynier, Veronique; Souquet, Jean-Marc; Bes, Magali; Le Bourvellec, Carine; Guyot, Sylvain; Orešič, Matej

    2012-01-01

    Purpose Syrah red grapes are used in the production of tannin-rich red wines. Tannins are high molecular weight molecules, proanthocyanidins (PAs), and poorly absorbed in the upper intestine. In this study, gut microbial metabolism of Syrah grape phenolic compounds was investigated. Methods Syrah grape pericarp was subjected to an enzymatic in vitro digestion model, and red wine and grape skin PA fraction were prepared. Microbial conversion was screened using an in vitro colon model with faec...

  19. CoMiniGut—a small volume in vitro colon model for the screening of gut microbial fermentation processes

    Science.gov (United States)

    Khakimov, Bekzod; Nielsen, Sebastian; Sørensen, Helena; van den Berg, Frans; Nielsen, Dennis Sandris

    2018-01-01

    Driven by the growing recognition of the influence of the gut microbiota (GM) on human health and disease, there is a rapidly increasing interest in understanding how dietary components, pharmaceuticals and pre- and probiotics influence GM. In vitro colon models represent an attractive tool for this purpose. With the dual objective of facilitating the investigation of rare and expensive compounds, as well as an increased throughput, we have developed a prototype in vitro parallel gut microbial fermentation screening tool with a working volume of only 5 ml consisting of five parallel reactor units that can be expanded with multiples of five to increase throughput. This allows e.g., the investigation of interpersonal variations in gut microbial dynamics and the acquisition of larger data sets with enhanced statistical inference. The functionality of the in vitro colon model, Copenhagen MiniGut (CoMiniGut) was first demonstrated in experiments with two common prebiotics using the oligosaccharide inulin and the disaccharide lactulose at 1% (w/v). We then investigated fermentation of the scarce and expensive human milk oligosaccharides (HMOs) 3-Fucosyllactose, 3-Sialyllactose, 6-Sialyllactose and the more common Fructooligosaccharide in fermentations with infant gut microbial communities. Investigations of microbial community composition dynamics in the CoMiniGut reactors by MiSeq-based 16S rRNA gene amplicon high throughput sequencing showed excellent experimental reproducibility and allowed us to extract significant differences in gut microbial composition after 24 h of fermentation for all investigated substrates and fecal donors. Furthermore, short chain fatty acids (SCFAs) were quantified for all treatments and donors. Fermentations with inulin and lactulose showed that inulin leads to a microbiota dominated by obligate anaerobes, with high relative abundance of Bacteroidetes, while the more easily fermented lactulose leads to higher relative abundance of

  20. CoMiniGut-a small volume in vitro colon model for the screening of gut microbial fermentation processes.

    Science.gov (United States)

    Wiese, Maria; Khakimov, Bekzod; Nielsen, Sebastian; Sørensen, Helena; van den Berg, Frans; Nielsen, Dennis Sandris

    2018-01-01

    Driven by the growing recognition of the influence of the gut microbiota (GM) on human health and disease, there is a rapidly increasing interest in understanding how dietary components, pharmaceuticals and pre- and probiotics influence GM. In vitro colon models represent an attractive tool for this purpose. With the dual objective of facilitating the investigation of rare and expensive compounds, as well as an increased throughput, we have developed a prototype in vitro parallel gut microbial fermentation screening tool with a working volume of only 5 ml consisting of five parallel reactor units that can be expanded with multiples of five to increase throughput. This allows e.g., the investigation of interpersonal variations in gut microbial dynamics and the acquisition of larger data sets with enhanced statistical inference. The functionality of the in vitro colon model, Copenhagen MiniGut (CoMiniGut) was first demonstrated in experiments with two common prebiotics using the oligosaccharide inulin and the disaccharide lactulose at 1% (w/v). We then investigated fermentation of the scarce and expensive human milk oligosaccharides (HMOs) 3-Fucosyllactose, 3-Sialyllactose, 6-Sialyllactose and the more common Fructooligosaccharide in fermentations with infant gut microbial communities. Investigations of microbial community composition dynamics in the CoMiniGut reactors by MiSeq-based 16S rRNA gene amplicon high throughput sequencing showed excellent experimental reproducibility and allowed us to extract significant differences in gut microbial composition after 24 h of fermentation for all investigated substrates and fecal donors. Furthermore, short chain fatty acids (SCFAs) were quantified for all treatments and donors. Fermentations with inulin and lactulose showed that inulin leads to a microbiota dominated by obligate anaerobes, with high relative abundance of Bacteroidetes, while the more easily fermented lactulose leads to higher relative abundance of

  1. CoMiniGut—a small volume in vitro colon model for the screening of gut microbial fermentation processes

    Directory of Open Access Journals (Sweden)

    Maria Wiese

    2018-01-01

    Full Text Available Driven by the growing recognition of the influence of the gut microbiota (GM on human health and disease, there is a rapidly increasing interest in understanding how dietary components, pharmaceuticals and pre- and probiotics influence GM. In vitro colon models represent an attractive tool for this purpose. With the dual objective of facilitating the investigation of rare and expensive compounds, as well as an increased throughput, we have developed a prototype in vitro parallel gut microbial fermentation screening tool with a working volume of only 5 ml consisting of five parallel reactor units that can be expanded with multiples of five to increase throughput. This allows e.g., the investigation of interpersonal variations in gut microbial dynamics and the acquisition of larger data sets with enhanced statistical inference. The functionality of the in vitro colon model, Copenhagen MiniGut (CoMiniGut was first demonstrated in experiments with two common prebiotics using the oligosaccharide inulin and the disaccharide lactulose at 1% (w/v. We then investigated fermentation of the scarce and expensive human milk oligosaccharides (HMOs 3-Fucosyllactose, 3-Sialyllactose, 6-Sialyllactose and the more common Fructooligosaccharide in fermentations with infant gut microbial communities. Investigations of microbial community composition dynamics in the CoMiniGut reactors by MiSeq-based 16S rRNA gene amplicon high throughput sequencing showed excellent experimental reproducibility and allowed us to extract significant differences in gut microbial composition after 24 h of fermentation for all investigated substrates and fecal donors. Furthermore, short chain fatty acids (SCFAs were quantified for all treatments and donors. Fermentations with inulin and lactulose showed that inulin leads to a microbiota dominated by obligate anaerobes, with high relative abundance of Bacteroidetes, while the more easily fermented lactulose leads to higher relative

  2. PhyloChip microarray analysis reveals altered gastrointestinal microbial communities in a rat model of colonic hypersensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, T.A.; Holmes, S.; Alekseyenko, A.V.; Shenoy, M.; DeSantis, T.; Wu, C.H.; Andersen, G.L.; Winston, J.; Sonnenburg, J.; Pasricha, P.J.; Spormann, A.

    2010-12-01

    Irritable bowel syndrome (IBS) is a chronic, episodic gastrointestinal disorder that is prevalent in a significant fraction of western human populations; and changes in the microbiota of the large bowel have been implicated in the pathology of the disease. Using a novel comprehensive, high-density DNA microarray (PhyloChip) we performed a phylogenetic analysis of the microbial community of the large bowel in a rat model in which intracolonic acetic acid in neonates was used to induce long lasting colonic hypersensitivity and decreased stool water content and frequency, representing the equivalent of human constipation-predominant IBS. Our results revealed a significantly increased compositional difference in the microbial communities in rats with neonatal irritation as compared with controls. Even more striking was the dramatic change in the ratio of Firmicutes relative to Bacteroidetes, where neonatally irritated rats were enriched more with Bacteroidetes and also contained a different composition of species within this phylum. Our study also revealed differences at the level of bacterial families and species. The PhyloChip is a useful and convenient method to study enteric microflora. Further, this rat model system may be a useful experimental platform to study the causes and consequences of changes in microbial community composition associated with IBS.

  3. Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils.

    Science.gov (United States)

    Habibul, Nuzahat; Hu, Yi; Sheng, Guo-Ping

    2016-11-15

    An investigation of the feasibility of in-situ electrokinetic remediation for toxic metal contaminated soil driven by microbial fuel cell (MFC) is presented. Results revealed that the weak electricity generated from MFC could power the electrokinetic remediation effectively. The metal removal efficiency and its influence on soil physiological properties were also investigated. With the electricity generated through the oxidation of organics in soils by microorganisms, the metals in the soils would mitigate from the anode to the cathode. The concentrations of Cd and Pb in the soils increased gradually through the anode to the cathode regions after remediation. After about 143days and 108 days' operation, the removal efficiencies of 31.0% and 44.1% for Cd and Pb at the anode region could be achieved, respectively. Soil properties such as pH and soil conductivity were also significantly redistributed from the anode to the cathode regions. The study shows that the MFC driving electrokinetic remediation technology is cost-effective and environmental friendly, with a promising application in soil remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Maternal antibiotic-induced early changes in microbial colonization selectively modulate colonic permeability and inducible heat shock proteins, and digesta concentrations of alkaline phosphatase and TLR-stimulants in swine offspring.

    Directory of Open Access Journals (Sweden)

    Marie-Edith Arnal

    Full Text Available Elevated intake of high energy diets is a risk factor for the development of metabolic diseases and obesity. High fat diets cause alterations in colonic microbiota composition and increase gut permeability to bacterial lipopolysaccharide, and subsequent low-grade chronic inflammation in mice. Chronic inflammatory bowel diseases are increasing worldwide and may involve alterations in microbiota-host dialog. Metabolic disorders appearing in later life are also suspected to reflect changes in early programming. However, how the latter affects the colon remains poorly studied. Here, we hypothesized that various components of colonic physiology, including permeability, ion exchange and protective inducible heat shock proteins (HSP are influenced in the short- and long-terms by early disturbances in microbial colonization. The hypothesis was tested in a swine model. Offspring were born to control mothers (n = 12 or mothers treated with the antibiotic (ATB amoxicillin around parturition (n = 11. Offspring were slaughtered between 14 and 42 days of age to study short-term effects. For long-term effects, young adult offspring from the same litters consumed a normal or a palm oil-enriched diet for 4 weeks between 140 and 169 days of age. ATB treatment transiently modified maternal fecal microbiota although the minor differences observed for offspring colonic microbiota were nonsignificant. In the short-term, consistently higher HSP27 and HSP70 levels and transiently increased horseradish peroxidase permeability in ATB offspring colon were observed. Importantly, long-term consequences included reduced colonic horseradish peroxidase permeability, and increased colonic digesta alkaline phosphatase (AP and TLR2- and TLR4-stimulant concentrations in rectal digesta in adult ATB offspring. Inducible HSP27 and HSP70 did not change. Interactions between early ATB treatment and later diet were noted for paracellular permeability and concentrations of colonic

  5. Initial Gut Microbial Composition as a Key Factor Driving Host Response to Antibiotic Treatment, as Exemplified by the Presence or Absence of Commensal Escherichia coli.

    Science.gov (United States)

    Ju, Tingting; Shoblak, Yasmeen; Gao, Yanhua; Yang, Kaiyuan; Fouhse, Janelle; Finlay, B Brett; So, Yee Wing; Stothard, Paul; Willing, Benjamin P

    2017-09-01

    Antibiotics are important for treating bacterial infection; however, efficacies and side effects of antibiotics vary in medicine and experimental models. A few studies have correlated microbiota composition variations with health outcomes in response to antibiotics; however, no study has demonstrated causality. We had noted variation in colonic expression of C-type lectins, regenerating islet-derived protein 3β (Reg3β) and Reg3γ, after metronidazole treatment in a mouse model. To investigate the effects of specific variations in the preexisting microbiome on host response to antibiotics, mice harboring a normal microbiota were allocated to 4 treatments in a 2-by-2 factorial arrangement with or without commensal Escherichia coli and with or without metronidazole in drinking water. E. coli colonized readily without causing a notable shift in the microbiota or host response. Metronidazole administration reduced microbiota biodiversity, indicated by decreased Chao1 and Shannon index values, and altered microbiota composition. However, the presence of E. coli strongly affected metronidazole-induced microbiota shifts. Remarkably, this single commensal bacterium in the context of a complex population led to variations in host responses to metronidazole treatment, including increased expression of antimicrobial peptides Reg3β and Reg3γ and intestinal inflammation indicated by tumor necrosis factor alpha levels. Similar results were obtained from 2-week antibiotic exposure and with additional E. coli isolates. The results of this proof-of-concept study indicate that even minor variations in initial commensal microbiota can drive shifts in microbial composition and host response after antibiotic administration. As well as providing an explanation for variability in animal models using antibiotics, the findings encourage the development of personalized medication in antibiotic therapies. IMPORTANCE This work provides an understanding of variability in studies where

  6. Soil type links microbial colonization of rice roots to methane emission

    NARCIS (Netherlands)

    Conrad, R.; Klose, M.; Noll, M.; Kemnitz, D.; Bodelier, P.L.E.

    2008-01-01

    Most of the methane (CH4) emission from rice fields is derived from plant photosynthates, which are converted to CH4. Rice cluster I (RC-1) archaea colonizing the rhizosphere were found to be the methanogens responsible for this process. Hence, RC-1 methanogens seem to play a crucial role in

  7. Different Land Use Intensities in Grassland Ecosystems Drive Ecology of Microbial Communities Involved in Nitrogen Turnover in Soil

    OpenAIRE

    Meyer, Annabel; Focks, Andreas; Radl, Viviane; Keil, Daniel; Welzl, Gerhard; Sch?ning, Ingo; Boch, Steffen; Marhan, Sven; Kandeler, Ellen; Schloter, Michael

    2013-01-01

    Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions,...

  8. The influence of stents on microbial colonization of the airway in children after slide tracheoplasty: a 14-year single-center experience.

    Science.gov (United States)

    Rijnberg, Friso M; Butler, Colin R; Speggiorin, Simone; Fierens, Anja; Wallis, Colin; Nouraei, Reza; McLaren, Clare A; Roebuck, Derek J; Hewitt, Richard; Elliott, Martin J

    2015-01-01

    This study describes the microbial colonization profile of the airway in children after slide tracheoplasty (STP) with and without stents, and compares colonization to children undergoing cardiothoracic surgical procedures without airway related disease. A 14-year retrospective single case note review was performed on patients undergoing STP and stent insertion. Nose and throat (NT) and bronchoalveolar lavage (BAL) specimens were analyzed for microbial profile and expressed as cumulative mean microorganisms per patient (MMP). Forty-three patients (median age ± SD 15.02 ± 31.76 months) underwent STP and 141 patients underwent cardiothoracic but no airway surgery (median age ± SD 31.7 ± 47.2 months). Sixteen patients required a stent after STP. One-hundred seventy-two positive microbial specimens were identified. The predominant 6 microorganisms were (1) Staphylococcus aureus; (2) Pseudomonas aeruginosa; (3) Haemophilus influenzae not type B; (4) Coliforms; (5) Streptococcus pneumoniae; and (6) Candida Albicans, and accounted for 128 (74%) of all positive specimens found. Children with stents had more MMP compared to children without stents after STP [4.06 ± 2.38 and 2.04 ± 2.24 MMP (P stents had more microbial colonization of their lower respiratory tract compared to their upper respiratory tract (3.36 ± 2.02 and 1.36 ± 0.93 MMP (P stents compared to children without stents after STP [0.5 and 0.15 MMP (P stents to be a significant risk factor for microbial colonization of the airway in children. More specifically airway stents appear to increase colonization in the distal airway, which appears unrelated to that of the upper respiratory tract. © 2014 Wiley Periodicals, Inc.

  9. Implant-abutment gap versus microbial colonization : Clinical significance based on a literature review

    NARCIS (Netherlands)

    Passos, Sheila Pestana; May, Liliana Gressler; Faria, Renata; Ozcan, Mutlu; Bottino, Marco Antonio

    2013-01-01

    Microorganisms from the oral cavity may settle at the implant-abutment interface (IAI). As a result, tissue inflammation could occur around these structures. The databases MEDLINE/PubMed and PubMed Central were used to identify articles published from 1981 through 2012 related to the microbial

  10. Predicted Bacterial Interactions Affect in Vivo Microbial Colonization Dynamics in Nematostella

    Science.gov (United States)

    Domin, Hanna; Zurita-Gutiérrez, Yazmín H.; Scotti, Marco; Buttlar, Jann; Hentschel Humeida, Ute; Fraune, Sebastian

    2018-01-01

    The maintenance and resilience of host-associated microbiota during development is a fundamental process influencing the fitness of many organisms. Several host properties were identified as influencing factors on bacterial colonization, including the innate immune system, mucus composition, and diet. In contrast, the importance of bacteria–bacteria interactions on host colonization is less understood. Here, we use bacterial abundance data of the marine model organism Nematostella vectensis to reconstruct potential bacteria–bacteria interactions through co-occurrence networks. The analysis indicates that bacteria–bacteria interactions are dynamic during host colonization and change according to the host’s developmental stage. To assess the predictive power of inferred interactions, we tested bacterial isolates with predicted cooperative or competitive behavior for their ability to influence bacterial recolonization dynamics. Within 3 days of recolonization, all tested bacterial isolates affected bacterial community structure, while only competitive bacteria increased bacterial diversity. Only 1 week after recolonization, almost no differences in bacterial community structure could be observed between control and treatments. These results show that predicted competitive bacteria can influence community structure for a short period of time, verifying the in silico predictions. However, within 1 week, the effects of the bacterial isolates are neutralized, indicating a high degree of resilience of the bacterial community. PMID:29740401

  11. Predicted Bacterial Interactions Affect in Vivo Microbial Colonization Dynamics in Nematostella

    Directory of Open Access Journals (Sweden)

    Hanna Domin

    2018-04-01

    Full Text Available The maintenance and resilience of host-associated microbiota during development is a fundamental process influencing the fitness of many organisms. Several host properties were identified as influencing factors on bacterial colonization, including the innate immune system, mucus composition, and diet. In contrast, the importance of bacteria–bacteria interactions on host colonization is less understood. Here, we use bacterial abundance data of the marine model organism Nematostella vectensis to reconstruct potential bacteria–bacteria interactions through co-occurrence networks. The analysis indicates that bacteria–bacteria interactions are dynamic during host colonization and change according to the host’s developmental stage. To assess the predictive power of inferred interactions, we tested bacterial isolates with predicted cooperative or competitive behavior for their ability to influence bacterial recolonization dynamics. Within 3 days of recolonization, all tested bacterial isolates affected bacterial community structure, while only competitive bacteria increased bacterial diversity. Only 1 week after recolonization, almost no differences in bacterial community structure could be observed between control and treatments. These results show that predicted competitive bacteria can influence community structure for a short period of time, verifying the in silico predictions. However, within 1 week, the effects of the bacterial isolates are neutralized, indicating a high degree of resilience of the bacterial community.

  12. Microbial Interactions With Dissolved Organic Matter Drive Carbon Dynamics and Community Succession

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    Xiaoqin Wu

    2018-06-01

    Full Text Available Knowledge of dynamic interactions between natural organic matter (NOM and microbial communities is critical not only to delineate the routes of NOM degradation/transformation and carbon (C fluxes, but also to understand microbial community evolution and succession in ecosystems. Yet, these processes in subsurface environments are usually studied independently, and a comprehensive view has been elusive thus far. In this study, we fed sediment-derived dissolved organic matter (DOM to groundwater microbes and continually analyzed microbial transformation of DOM over a 50-day incubation. To document fine-scale changes in DOM chemistry, we applied high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS and soft X-ray absorption spectroscopy (sXAS. We also monitored the trajectory of microbial biomass, community structure and activity over this time period. Together, these analyses provided an unprecedented comprehensive view of interactions between sediment-derived DOM and indigenous subsurface groundwater microbes. Microbial decomposition of labile C in DOM was immediately evident from biomass increase and total organic carbon (TOC decrease. The change of microbial composition was closely related to DOM turnover: microbial community in early stages of incubation was influenced by relatively labile tannin- and protein-like compounds; while in later stages the community composition evolved to be most correlated with less labile lipid- and lignin-like compounds. These changes in microbial community structure and function, coupled with the contribution of microbial products to DOM pool affected the further transformation of DOM, culminating in stark changes to DOM composition over time. Our study demonstrates a distinct response of microbial communities to biotransformation of DOM, which improves our understanding of coupled interactions between sediment-derived DOM, microbial processes, and community structure in

  13. Effect of Aging on Periodontal Inflammation, Microbial Colonization, and Disease Susceptibility.

    Science.gov (United States)

    Wu, Y; Dong, G; Xiao, W; Xiao, E; Miao, F; Syverson, A; Missaghian, N; Vafa, R; Cabrera-Ortega, A A; Rossa, C; Graves, D T

    2016-04-01

    Periodontitis is a chronic inflammatory disease induced by a biofilm that forms on the tooth surface. Increased periodontal disease is associated with aging. We investigated the effect of aging on challenge by oral pathogens, examining the host response, colonization, and osteoclast numbers in aged versus young mice. We also compared the results with mice with lineage-specific deletion of the transcription factor FOXO1, which reduces dendritic cell (DC) function. Periodontitis was induced by oral inoculation of Porphyromonas gingivalis and Fusobacterium nucleatum in young (4 to 5 mo) and aged (14 to 15 mo) mice. Aged mice as well as mice with reduced DC function had decreased numbers of DCs in lymph nodes, indicative of a diminished host response. In vitro studies suggest that reduced DC numbers in lymph nodes of aged mice may involve the effect of advanced glycation end products on DC migration. Surprisingly, aged mice but not mice with genetically altered DC function had greater production of antibody to P. gingivalis, greater IL-12 expression, and more plasma cells in lymph nodes following oral inoculation as compared with young mice. The greater adaptive immune response in aged versus young mice was linked to enhanced levels of P. gingivalis and reduced bacterial diversity. Thus, reduced bacterial diversity in aged mice may contribute to increased P. gingivalis colonization following inoculation and increased periodontal disease susceptibility, reflected by higher TNF levels and osteoclast numbers in the periodontium of aged versus young mice. © International & American Associations for Dental Research 2016.

  14. Water regime history drives responses of soil Namib Desert microbial communities to wetting events

    Science.gov (United States)

    Frossard, Aline; Ramond, Jean-Baptiste; Seely, Mary; Cowan, Don A.

    2015-07-01

    Despite the dominance of microorganisms in arid soils, the structures and functional dynamics of microbial communities in hot deserts remain largely unresolved. The effects of wetting event frequency and intensity on Namib Desert microbial communities from two soils with different water-regime histories were tested over 36 days. A total of 168 soil microcosms received wetting events mimicking fog, light rain and heavy rainfall, with a parallel “dry condition” control. T-RFLP data showed that the different wetting events affected desert microbial community structures, but these effects were attenuated by the effects related to the long-term adaptation of both fungal and bacterial communities to soil origins (i.e. soil water regime histories). The intensity of the water pulses (i.e. the amount of water added) rather than the frequency of wetting events had greatest effect in shaping bacterial and fungal community structures. In contrast to microbial diversity, microbial activities (enzyme activities) showed very little response to the wetting events and were mainly driven by soil origin. This experiment clearly demonstrates the complexity of microbial community responses to wetting events in hyperarid hot desert soil ecosystems and underlines the dynamism of their indigenous microbial communities.

  15. Mean Annual Temperature Drives Microbial Nitrogen Cycling and Fine Root Nutrient Foraging Across a Tropical Montane Wet Forest Elevation Gradient

    Science.gov (United States)

    Pierre, S.; Litton, C. L. M.; Giardina, C. P.; Sparks, J. P.; Groffman, P. M.; Hewson, I.; Fahey, T. J.

    2017-12-01

    Mean annual temperature (MAT) is positively correlated with rates of primary production and carbon (C) turnover in forests globally, but the underlying biotic drivers of these relationships remain poorly resolved. We hypothesized that (1) MAT increases nitrifier abundance and thereby nitrate (NO-) bioavailability in soils and (2) increased NO- bioavailability reduces fine root nitrogen (N) demand. We used an ecologically well-constrained natural elevation gradient (13˚C -18˚C) in a tropical wet motane forest on the Island of Hawaii to study to role of MAT in situ. Our previous work showed that MAT drives increased soil NO- bioavailability in situ (r²=0.79, P=0.003), and indicated that the abundance of ammonia oxidizing archaea is strongly and positively correlated with MAT in situ (r²=0.34, Preduce fine root foraging effort. Further, higher MAT and greater N fertility in soils may reduce the C limitation of AM fungal colonization. We conclude that MAT drives N-rich conditions, which allow for lower N foraging effort, but greater C investment in P acquisition through AM fine root colonization.

  16. How Do Landscape Structure, Management and Habitat Quality Drive the Colonization of Habitat Patches by the Dryad Butterfly (Lepidoptera: Satyrinae) in Fragmented Grassland?

    Science.gov (United States)

    Kalarus, Konrad; Nowicki, Piotr

    2015-01-01

    Most studies dealing with species distribution patterns on fragmented landscapes focus on the characteristics of habitat patches that influence local occurrence and abundance, but they tend to neglect the question of what drives colonization of previously unoccupied patches. In a study of the dryad butterfly, we combined classical approaches derived from metapopulation theory and landscape ecology to investigate the factors driving colonization from a recent refugium. In three consecutive transect surveys, we recorded the presence and numbers of imagos in 27 patches of xerothermic grassland and 26 patches of wet meadow. Among the predictors affecting the occurrence and abundance of the dryad, we considered environmental variables reflecting (i) habitat patch quality (e.g., goldenrod cover, shrub density, vegetation height); (ii) factors associated with habitat spatial structure (patch size, patch isolation and fragmentation); and (iii) features of patch surroundings (100-m buffers around patches) that potentially pose barriers or provide corridors. Patch colonization by the dryad was strongly limited by the distance from the species refugium in the region; there was a slight positive effect of shrub density in this respect. Butterfly abundance increased in smaller and more fragmented habitat patches; it was negatively impacted by invasive goldenrod cover, and positively influenced by the density of watercourses in patch surroundings. Nectar plant availability was positively related to species abundance in xerothermic grassland, while in wet meadow the effect was the reverse. We conclude that dryad colonization of our study area is very recent, since the most important factor limiting colonization was distance from the refugium, while the habitat quality of target patches had less relevance. In order to preserve the species, conservation managers should focus on enhancing the quality of large patches and should also direct their efforts on smaller and more

  17. How Do Landscape Structure, Management and Habitat Quality Drive the Colonization of Habitat Patches by the Dryad Butterfly (Lepidoptera: Satyrinae in Fragmented Grassland?

    Directory of Open Access Journals (Sweden)

    Konrad Kalarus

    Full Text Available Most studies dealing with species distribution patterns on fragmented landscapes focus on the characteristics of habitat patches that influence local occurrence and abundance, but they tend to neglect the question of what drives colonization of previously unoccupied patches. In a study of the dryad butterfly, we combined classical approaches derived from metapopulation theory and landscape ecology to investigate the factors driving colonization from a recent refugium. In three consecutive transect surveys, we recorded the presence and numbers of imagos in 27 patches of xerothermic grassland and 26 patches of wet meadow. Among the predictors affecting the occurrence and abundance of the dryad, we considered environmental variables reflecting (i habitat patch quality (e.g., goldenrod cover, shrub density, vegetation height; (ii factors associated with habitat spatial structure (patch size, patch isolation and fragmentation; and (iii features of patch surroundings (100-m buffers around patches that potentially pose barriers or provide corridors. Patch colonization by the dryad was strongly limited by the distance from the species refugium in the region; there was a slight positive effect of shrub density in this respect. Butterfly abundance increased in smaller and more fragmented habitat patches; it was negatively impacted by invasive goldenrod cover, and positively influenced by the density of watercourses in patch surroundings. Nectar plant availability was positively related to species abundance in xerothermic grassland, while in wet meadow the effect was the reverse. We conclude that dryad colonization of our study area is very recent, since the most important factor limiting colonization was distance from the refugium, while the habitat quality of target patches had less relevance. In order to preserve the species, conservation managers should focus on enhancing the quality of large patches and should also direct their efforts on smaller and

  18. Differences in the Microbial Colonization Among Arch Wire Types, Gauges and Cross Sections

    Directory of Open Access Journals (Sweden)

    Reem A. Rafeeq

    2018-02-01

    Full Text Available Background: The presence of orthodontic materials in the oral cavity represent a unique surface that can interact with bacteria, leading to pathogenic plaque formation and subsequent enamel demineralization, Streptococcus mutans play an important role in the initiation and progression of dental caries and they are considered the primary cause of bacteriological caries. The objective of this study was to investigate the effect of multiple factors including the type of arch wire, salivary coating, cross section, and wire thickness on the levels of mutans streptococci adherence. Materials and Methods: Two types of arch wire stainless steel and nickel titanium were selected using the following criteria: round and rectangular with gauges 0.014, 0.018, 0.016 × 0.022 and 0.019 × 0.0 25 inches which were subdivided into eight groups. Bacterial adhesion was quantified by a microbial culture technique and the number of adhesive bacteria were analyzed and counted after growth in culture for each group with and without saliva coating at 15 and 60 minutes. Detection of mutans streptococci by saliva-check Mutans test. Results: There was a significant difference between arch wire types in each time interval and the highest bacterial adhesion on the NiTi arch wires with rectangular cross section in the absence of saliva with extended incubation time. Conclusions: The adherence of mutans streptococci in saliva coated wires seems to be low. At increased incubation time, rectangular cross section arch wire showed an increased number of adhering bacteria with less effect on different gauges of the arch wire.

  19. Syntrophic interactions drive the hydrogen production from glucose at low temperature in microbial electrolysis cells

    KAUST Repository

    Lu, Lu; Xing, Defeng; Ren, Nanqi; Logan, Bruce E.

    2012-01-01

    H2 can be obtained from glucose by fermentation at mesophilic temperatures, but here we demonstrate that hydrogen can also be obtained from glucose at low temperatures using microbial electrolysis cells (MECs). H2 was produced from glucose at 4°C

  20. Natural and artificial feeding management before weaning promote different rumen microbial colonization but not differences in gene expression levels at the rumen epithelium of newborn goats.

    Science.gov (United States)

    Abecia, Leticia; Jiménez, Elisabeth; Martínez-Fernandez, Gonzalo; Martín-García, A Ignacio; Ramos-Morales, Eva; Pinloche, Eric; Denman, Stuart E; Newbold, C Jamie; Yáñez-Ruiz, David R

    2017-01-01

    The aim of this work was to evaluate the effect of feeding management during the first month of life (natural with the mother, NAT, or artificial with milk replacer, ART) on the rumen microbial colonization and the host innate immune response. Thirty pregnant goats carrying two fetuses were used. At birth one kid was taken immediately away from the doe and fed milk replacer (ART) while the other remained with the mother (NAT). Kids from groups received colostrum during first 2 days of life. Groups of four kids (from ART and NAT experimental groups) were slaughtered at 1, 3, 7, 14, 21 and 28 days of life. On the sampling day, after slaughtering, the rumen content was sampled and epithelial rumen tissue was collected. Pyrosequencing analyses of the bacterial community structure on samples collected at 3, 7, 14 and 28 days showed that both systems promoted significantly different colonization patterns (P = 0.001). Diversity indices increased with age and were higher in NAT feeding system. Lower mRNA abundance was detected in TLR2, TLR8 and TLR10 in days 3 and 5 compared to the other days (7, 14, 21 and 28). Only TLR5 showed a significantly different level of expression according to the feeding system, presenting higher mRNA abundances in ART kids. PGLYRP1 showed significantly higher abundance levels in days 3, 5 and 7, and then experienced a decline independently of the feeding system. These observations confirmed a highly diverse microbial colonisation from the first day of life in the undeveloped rumen, and show that the colonization pattern substantially differs between pre-ruminants reared under natural or artificial milk feeding systems. However, the rumen epithelial immune development does not differentially respond to distinct microbial colonization patterns.

  1. Natural and artificial feeding management before weaning promote different rumen microbial colonization but not differences in gene expression levels at the rumen epithelium of newborn goats.

    Directory of Open Access Journals (Sweden)

    Leticia Abecia

    Full Text Available The aim of this work was to evaluate the effect of feeding management during the first month of life (natural with the mother, NAT, or artificial with milk replacer, ART on the rumen microbial colonization and the host innate immune response. Thirty pregnant goats carrying two fetuses were used. At birth one kid was taken immediately away from the doe and fed milk replacer (ART while the other remained with the mother (NAT. Kids from groups received colostrum during first 2 days of life. Groups of four kids (from ART and NAT experimental groups were slaughtered at 1, 3, 7, 14, 21 and 28 days of life. On the sampling day, after slaughtering, the rumen content was sampled and epithelial rumen tissue was collected. Pyrosequencing analyses of the bacterial community structure on samples collected at 3, 7, 14 and 28 days showed that both systems promoted significantly different colonization patterns (P = 0.001. Diversity indices increased with age and were higher in NAT feeding system. Lower mRNA abundance was detected in TLR2, TLR8 and TLR10 in days 3 and 5 compared to the other days (7, 14, 21 and 28. Only TLR5 showed a significantly different level of expression according to the feeding system, presenting higher mRNA abundances in ART kids. PGLYRP1 showed significantly higher abundance levels in days 3, 5 and 7, and then experienced a decline independently of the feeding system. These observations confirmed a highly diverse microbial colonisation from the first day of life in the undeveloped rumen, and show that the colonization pattern substantially differs between pre-ruminants reared under natural or artificial milk feeding systems. However, the rumen epithelial immune development does not differentially respond to distinct microbial colonization patterns.

  2. Nitrogen availability drives priming effect by altering microbial carbon-use efficiency after permafrost thaw

    Science.gov (United States)

    Chen, L.; Liu, L.; Zhang, Q.; Mao, C.; Liu, F.; Yang, Y.

    2017-12-01

    Enhanced vegetation growth can potentially aggravate soil C loss by accelerating the decomposition of soil organic matter (SOM) ("priming effect"), thereby reinforcing the positive C-climate feedback in permafrost ecosystems. However, the degree to which priming effect alters permafrost C dynamics is expected to be modified by nitrogen (N) availability after permafrost thaw. Despite this recognition, experimental evidence for the linkage between priming effect and post-thaw N availability is still lacking. Particularly, the microbial mechanisms involved remain unknown. Here, using a thermokarst-induced natural N gradient combined with an isotope-labeled glucose and N addition experiment, we presented a strong linkage between soil N availability and priming effect in Tibetan permafrost. We observed that the magnitude of priming effect along the thaw gradient was negatively associated with soil total dissolved nitrogen (TDN) concentration. This negative effect of post-thaw N availability was further proved by a sharply reduced priming effect following mineral N supply. These two lines of evidence jointly illustrated that the priming effect along the thaw chronosequence was controlled by N availability, supporting the `N mining theory'. In contrast to the prevailing assumption, this N-regulated priming effect was independent from changes in C- or N-acquiring enzyme activities, but positively associated with the change in metabolic quotients (△SOM-qCO2), highlighting that decreased microbial metabolism efficiency rather than increased enzyme activities account for greater priming effect under reduced N availability. Taken together, these findings demonstrate that C dynamics in melting permafrost largely depends on post-thaw N availability due to its effect of retarding SOM mineralization. This C-N interaction and the relevant microbial metabolic efficiency should be considered in Earth System Models for a better understanding of soil C dynamics after permafrost thaw.

  3. Microbial colonization of Ca-sulfate crusts in the hyperarid core of the Atacama Desert: implications for the search for life on Mars.

    Science.gov (United States)

    Wierzchos, J; Cámara, B; de Los Ríos, A; Davila, A F; Sánchez Almazo, I M; Artieda, O; Wierzchos, K; Gómez-Silva, B; McKay, C; Ascaso, C

    2011-01-01

    The scarcity of liquid water in the hyperarid core of the Atacama Desert makes this region one of the most challenging environments for life on Earth. The low numbers of microbial cells in the soils suggest that within the Atacama Desert lies the dry limit for life on our planet. Here, we show that the Ca-sulfate crusts of this hyperarid core are the habitats of lithobiontic micro-organisms. This microporous, translucent substrate is colonized by epilithic lichens, as well as endolithic free-living algae, fungal hyphae, cyanobacteria and non photosynthetic bacteria. We also report a novel type of endolithic community, "hypoendoliths", colonizing the undermost layer of the crusts. The colonization of gypsum crusts within the hyperarid core appears to be controlled by the moisture regime. Our data shows that the threshold for colonization is crossed within the dry core, with abundant colonization in gypsum crusts at one study site, while crusts at a drier site are virtually devoid of life. We show that the cumulative time in 1 year of relative humidity (RH) above 60% is the best parameter to explain the difference in colonization between both sites. This is supported by controlled humidity experiments, where we show that colonies of endolithic cyanobacteria in the Ca-sulfate crust undergo imbibition process at RH >60%. Assuming that life once arose on Mars, it is conceivable that Martian micro-organisms sought refuge in similar isolated evaporite microenvironments during their last struggle for life as their planet turned arid. © 2010 Blackwell Publishing Ltd.

  4. RBP4-STRA6 Pathway Drives Cancer Stem Cell Maintenance and Mediates High-Fat Diet-Induced Colon Carcinogenesis

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    Sheelarani Karunanithi

    2017-08-01

    Full Text Available The transmembrane protein, STRA6, functions as a vitamin A transporter and a cytokine receptor when activated by vitamin A-bound serum retinol binding protein 4 (RBP4. STRA6 activation transduces a JAK2-STAT3 signaling cascade and promotes tumorigenesis in a xenograft mouse model of colon cancer. We show here that RBP4 and STRA6 expression is associated with poor oncologic prognosis. Downregulating STRA6 or RBP4 in colon cancer cells decreased the fraction of cancer stem cells and their sphere and tumor initiation frequency. Furthermore, we show that high-fat diet (HFD increases LGR5 expression and promotes tumor growth in a xenograft model independent of obesity. HFD increased STRA6 levels, and downregulation of STRA6 delays and impairs tumor initiation, tumor growth, and expression of stemness markers. Together, these data demonstrate a key role of STRA6 and RBP4 in the maintenance of colon cancer self-renewal and that this pathway is an important link through which consumption of HFD contributes to colon carcinogenesis.

  5. Host Ecology Rather Than Host Phylogeny Drives Amphibian Skin Microbial Community Structure in the Biodiversity Hotspot of Madagascar.

    Science.gov (United States)

    Bletz, Molly C; Archer, Holly; Harris, Reid N; McKenzie, Valerie J; Rabemananjara, Falitiana C E; Rakotoarison, Andolalao; Vences, Miguel

    2017-01-01

    ) was enriched on terrestrial frogs. The presence of shared bacterial OTUs across geographic regions for selected host genera suggests the presence of core microbial communities which in Madagascar, might be driven more strongly by a species' preference for specific microhabitats than by the physical, physiological or biochemical properties of their skin. These results corroborate that both host and environmental factors are driving community assembly of amphibian cutaneous microbial communities, and provide an improved foundation for elucidating their role in disease resistance.

  6. Host Ecology Rather Than Host Phylogeny Drives Amphibian Skin Microbial Community Structure in the Biodiversity Hotspot of Madagascar

    Science.gov (United States)

    Bletz, Molly C.; Archer, Holly; Harris, Reid N.; McKenzie, Valerie J.; Rabemananjara, Falitiana C. E.; Rakotoarison, Andolalao; Vences, Miguel

    2017-01-01

    ) was enriched on terrestrial frogs. The presence of shared bacterial OTUs across geographic regions for selected host genera suggests the presence of core microbial communities which in Madagascar, might be driven more strongly by a species’ preference for specific microhabitats than by the physical, physiological or biochemical properties of their skin. These results corroborate that both host and environmental factors are driving community assembly of amphibian cutaneous microbial communities, and provide an improved foundation for elucidating their role in disease resistance. PMID:28861051

  7. Host Ecology Rather Than Host Phylogeny Drives Amphibian Skin Microbial Community Structure in the Biodiversity Hotspot of Madagascar

    Directory of Open Access Journals (Sweden)

    Molly C. Bletz

    2017-08-01

    (Rhizobiaceae was enriched on terrestrial frogs. The presence of shared bacterial OTUs across geographic regions for selected host genera suggests the presence of core microbial communities which in Madagascar, might be driven more strongly by a species’ preference for specific microhabitats than by the physical, physiological or biochemical properties of their skin. These results corroborate that both host and environmental factors are driving community assembly of amphibian cutaneous microbial communities, and provide an improved foundation for elucidating their role in disease resistance.

  8. Pharmacokinetics, microbial response, and pulmonary outcomes of multidose intravenous azithromycin in preterm infants at risk for Ureaplasma respiratory colonization.

    Science.gov (United States)

    Merchan, L Marcela; Hassan, Hazem E; Terrin, Michael L; Waites, Ken B; Kaufman, David A; Ambalavanan, Namasivayam; Donohue, Pamela; Dulkerian, Susan J; Schelonka, Robert; Magder, Laurence S; Shukla, Sagar; Eddington, Natalie D; Viscardi, Rose M

    2015-01-01

    The study objectives were to refine the population pharmacokinetics (PK) model, determine microbial clearance, and assess short-term pulmonary outcomes of multiple-dose azithromycin treatment in preterm infants at risk for Ureaplasma respiratory colonization. Fifteen subjects (7 of whom were Ureaplasma positive) received intravenous azithromycin at 20 mg/kg of body weight every 24 h for 3 doses. Azithromycin concentrations were determined in plasma samples obtained up to 168 h post-first dose by using a validated liquid chromatography-tandem mass spectrometry method. Respiratory samples were obtained predose and at three time points post-last dose for Ureaplasma culture, PCR, antibiotic susceptibility testing, and cytokine concentration determinations. Pharmacokinetic data from these 15 subjects as well as 25 additional subjects (who received either a single 10-mg/kg dose [n = 12] or a single 20-mg/kg dose [n = 13]) were analyzed by using a nonlinear mixed-effect population modeling (NONMEM) approach. Pulmonary outcomes were assessed at 36 weeks post-menstrual age and 6 months adjusted age. A 2-compartment model with all PK parameters allometrically scaled on body weight best described the azithromycin pharmacokinetics in preterm neonates. The population pharmacokinetics parameter estimates for clearance, central volume of distribution, intercompartmental clearance, and peripheral volume of distribution were 0.15 liters/h · kg(0.75), 1.88 liters · kg, 1.79 liters/h · kg(0.75), and 13 liters · kg, respectively. The estimated area under the concentration-time curve over 24 h (AUC24)/MIC90 value was ∼ 4 h. All posttreatment cultures were negative, and there were no drug-related adverse events. One Ureaplasma-positive infant died at 4 months of age, but no survivors were hospitalized for respiratory etiologies during the first 6 months (adjusted age). Thus, a 3-day course of 20 mg/kg/day intravenous azithromycin shows preliminary efficacy in eradicating

  9. Characterization of microbial metabolism of Syrah grape products in an in vitro colon model using targeted and non-targeted analytical approaches.

    Science.gov (United States)

    Aura, Anna-Marja; Mattila, Ismo; Hyötyläinen, Tuulia; Gopalacharyulu, Peddinti; Cheynier, Veronique; Souquet, Jean-Marc; Bes, Magali; Le Bourvellec, Carine; Guyot, Sylvain; Orešič, Matej

    2013-03-01

    Syrah red grapes are used in the production of tannin-rich red wines. Tannins are high molecular weight molecules, proanthocyanidins (PAs), and poorly absorbed in the upper intestine. In this study, gut microbial metabolism of Syrah grape phenolic compounds was investigated. Syrah grape pericarp was subjected to an enzymatic in vitro digestion model, and red wine and grape skin PA fraction were prepared. Microbial conversion was screened using an in vitro colon model with faecal microbiota, by measurement of short-chain fatty acids by gas chromatography (GC) and microbial phenolic metabolites using GC with mass detection (GC-MS). Red wine metabolites were further profiled using two-dimensional GC mass spectrometry (GCxGC-TOFMS). In addition, the effect of PA structure and dose on conversion efficiency was investigated by GC-MS. Red wine exhibited a higher degree of C1-C3 phenolic acid formation than PA fraction or grape pericarp powders. Hydroxyphenyl valeric acid (flavanols and PAs as precursors) and 3,5-dimethoxy-4-hydroxybenzoic acid (anthocyanin as a precursor) were identified from the red wine metabolite profile. In the absence of native grape pericarp or red wine matrix, the isolated PAs were found to be effective in the dose-dependent inhibition of microbial conversions and short-chain fatty acid formation. Metabolite profiling was complementary to targeted analysis. The identified metabolites had biological relevance, because the structures of the metabolites resembled fragments of their grape phenolic precursors or were in agreement with literature data.

  10. Syntrophic interactions drive the hydrogen production from glucose at low temperature in microbial electrolysis cells

    KAUST Repository

    Lu, Lu

    2012-11-01

    H2 can be obtained from glucose by fermentation at mesophilic temperatures, but here we demonstrate that hydrogen can also be obtained from glucose at low temperatures using microbial electrolysis cells (MECs). H2 was produced from glucose at 4°C in single-chamber MECs at a yield of about 6mol H2mol-1 glucose, and at rates of 0.25±0.03-0.37±0.04m3 H2m-3d-1. Pyrosequencing of 16S rRNA gene and electrochemical analyses showed that syntrophic interactions combining glucose fermentation with the oxidization of fermentation products by exoelectrogens was the predominant pathway for current production at a low temperature other than direct glucose oxidization by exoelectrogens. Another syntrophic interaction, methanogenesis and homoacetogenesis, which have been found in 25°C reactors, were not detected in MECs at 4°C. These results demonstrate the feasibility of H2 production from abundant biomass of carbohydrates at low temperature in MECs. © 2012 Elsevier Ltd.

  11. Synthetic biology for manufacturing chemicals: constraints drive the use of non-conventional microbial platforms.

    Science.gov (United States)

    Czajka, Jeffrey; Wang, Qinhong; Wang, Yechun; Tang, Yinjie J

    2017-10-01

    Genetically modified microbes have had much industrial success producing protein-based products (such as antibodies and enzymes). However, engineering microbial workhorses for biomanufacturing of commodity compounds remains challenging. First, microbes cannot afford burdens with both overexpression of multiple enzymes and metabolite drainage for product synthesis. Second, synthetic circuits and introduced heterologous pathways are not yet as "robust and reliable" as native pathways due to hosts' innate regulations, especially under suboptimal fermentation conditions. Third, engineered enzymes may lack channeling capabilities for cascade-like transport of metabolites to overcome diffusion barriers or to avoid intermediate toxicity in the cytoplasmic environment. Fourth, moving engineered hosts from laboratory to industry is unreliable because genetic mutations and non-genetic cell-to-cell variations impair the large-scale fermentation outcomes. Therefore, synthetic biology strains often have unsatisfactory industrial performance (titer/yield/productivity). To overcome these problems, many different species are being explored for their metabolic strengths that can be leveraged to synthesize specific compounds. Here, we provide examples of non-conventional and genetically amenable species for industrial manufacturing, including the following: Corynebacterium glutamicum for its TCA cycle-derived biosynthesis, Yarrowia lipolytica for its biosynthesis of fatty acids and carotenoids, cyanobacteria for photosynthetic production from its sugar phosphate pathways, and Rhodococcus for its ability to biotransform recalcitrant feedstock. Finally, we discuss emerging technologies (e.g., genome-to-phenome mapping, single cell methods, and knowledge engineering) that may facilitate the development of novel cell factories.

  12. Genomes in Turmoil: Frugality Drives Microbial Community Structure in Extremely Acidic Environments

    Science.gov (United States)

    Holmes, D. S.

    2016-12-01

    Extremely acidic environments (To gain insight into these issues, we have conducted deep bioinformatic analyses, including metabolic reconstruction of key assimilatory pathways, phylogenomics and network scrutiny of >160 genomes of acidophiles, including representatives from Archaea, Bacteria and Eukarya and at least ten metagenomes of acidic environments [Cardenas JP, et al. pp 179-197 in Acidophiles, eds R. Quatrini and D. B. Johnson, Caister Academic Press, UK (2016)]. Results yielded valuable insights into cellular processes, including carbon and nitrogen management and energy production, linking biogeochemical processes to organismal physiology. They also provided insight into the evolutionary forces that shape the genomic structure of members of acidophile communities. Niche partitioning can explain diversity patterns in rapidly changing acidic environments such as bioleaching heaps. However, in spatially and temporally homogeneous acidic environments genome flux appears to provide deeper insight into the composition and evolution of acidic consortia. Acidophiles have undergone genome streamlining by gene loss promoting mutual coexistence of species that exploit complementarity use of scarce resources consistent with the Black Queen hypothesis [Morris JJ et al. mBio 3: e00036-12 (2012)]. Acidophiles also have a large pool of accessory genes (the microbial super-genome) that can be accessed by horizontal gene transfer. This further promotes dependency relationships as drivers of community structure and the evolution of keystone species. Acknowledgements: Fondecyt 1130683; Basal CCTE PFB16

  13. Lack of STAT6 Attenuates Inflammation and Drives Protection against Early Steps of Colitis-Associated Colon Cancer.

    Science.gov (United States)

    Leon-Cabrera, Sonia A; Molina-Guzman, Emmanuel; Delgado-Ramirez, Yael G; Vázquez-Sandoval, Armando; Ledesma-Soto, Yadira; Pérez-Plasencia, Carlos G; Chirino, Yolanda I; Delgado-Buenrostro, Norma L; Rodríguez-Sosa, Miriam; Vaca-Paniagua, Felipe; Ávila-Moreno, Federico; Gutierrez-Cirlos, Emma B; Arias-Romero, Luis E; Terrazas, Luis I

    2017-05-01

    Colitis-associated colon cancer (CAC) is one of the most common malignant neoplasms and a leading cause of death. The immunologic factors associated with CAC development are not completely understood. Signal transducer and activator of transcription 6 (STAT6) is part of an important signaling pathway for modulating intestinal immune function and homeostasis. However, the role of STAT6 in colon cancer progression is unclear. Following CAC induction in wild-type (WT) and STAT6-deficient mice (STAT6 -/- ), we found that 70% of STAT6 -/- mice were tumor-free after 8 weeks, whereas 100% of WT mice developed tumors. STAT6 -/- mice displayed fewer and smaller colorectal tumors than WT mice; this reduced tumorigenicity was associated with decreased proliferation and increased apoptosis in the colonic mucosa in the early steps of tumor progression. STAT6 -/- mice also exhibited reduced inflammation, diminished concentrations COX2 and nuclear β-catenin protein in the colon, and decreased mRNA expression of IL17A and TNFα, but increased IL10 expression when compared with WT mice. Impaired mucosal expression of CCL9, CCL25, and CXCR2 was also observed. In addition, the number of circulating CD11b + Ly6C hi CCR2 + monocytes and CD11b + Ly6C low Ly6G + granulocytes was both decreased in a STAT6-dependent manner. Finally, WT mice receiving a STAT6 inhibitor in vivo confirmed a significant reduction in tumor load as well as less intense signs of CAC. Our results demonstrate that STAT6 is critical in the early steps of CAC development for modulating inflammatory responses and controlling cell recruitment and proliferation. Thus, STAT6 may represent a promising target for CAC treatment. Cancer Immunol Res; 5(5); 385-96. ©2017 AACR . ©2017 American Association for Cancer Research.

  14. Low concentration of copper inhibits colonization of soil by the arbuscular mycorrhizal fungus Glomus intraradices and radically changes the microbial community structure

    DEFF Research Database (Denmark)

    Hagerberg, David; Manique, Nina; Brandt, Kristian K.

    2011-01-01

    . To avoid indirect effects through the plant, copper was only added to root-free microcosm compartments. [Cu]bio was measured using a Pseudomonas fluorescens biosensor strain. In the range of 0–1.5 μg g−1 [Cu]bio, a log–log linear relationship between added copper and [Cu]bio was found. Microbial...... colonization of the root-free compartment was evaluated by whole-cell fatty acid analysis (WCFA) and amplified rDNA restriction analysis (ARDRA). The WCFA analysis showed that the AM fungus soil colonization was severely inhibited by Cu with a 50% reduction of mycorrhizal growth at 0.26 μg g−1 [Cu......]bio. The growth of other main microbial groups was not significantly affected by copper. However, ARDRA analysis showed a very strong effect of copper on the bacterial community composition probably caused by an increased proportion of Cu-resistant bacteria. Our results suggest that problems with plant yield may...

  15. Neonatal microbial colonization in mice promotes prolonged dominance of CD11b+Gr-1+cells and accelerated establishment of the CD4+T cell population in the spleen

    DEFF Research Database (Denmark)

    Kristensen, Matilde Bylov; Metzdorff, Stine Broeng; Bergström, Anders

    2015-01-01

    To assess the microbial influence on postnatal hematopoiesis, we examined the role of early life microbial colonization on the composition of leukocyte subsets in the neonatal spleen. A high number of CD11b+Gr-1+ splenocytes present perinatally was sustained for a longer period in conventionally...... event, which we suggest impacts the subsequent development of the T cell population in the murine spleen....

  16. Rhizosphere effect of colonizer plant species on the development of soil microbial community during primary succession on postmining sites

    Czech Academy of Sciences Publication Activity Database

    Elhottová, Dana; Krištůfek, Václav; Malý, S.; Frouz, Jan

    2009-01-01

    Roč. 40, 1-6 (2009), s. 758-770 ISSN 0010-3624 R&D Projects: GA MŠk LC06066; GA ČR GA526/03/1259 Institutional research plan: CEZ:AV0Z60660521 Keywords : colonizer plant * colliery spoil substrate * rhizosphere effect Subject RIV: EH - Ecology, Behaviour Impact factor: 0.397, year: 2009

  17. An APC:WNT counter-current-like mechanism regulates cell division along the colonic crypt axis: a mechanism that explains how APC mutations induce proliferative abnormalities that drive colon cancer development.

    Directory of Open Access Journals (Sweden)

    Bruce M Boman

    2013-11-01

    Full Text Available APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside. WNT signaling, in contrast, is high at the bottom (where SCs reside and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g. survivin are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric. APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly-proliferating cells during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes.

  18. An APC:WNT Counter-Current-Like Mechanism Regulates Cell Division Along the Human Colonic Crypt Axis: A Mechanism That Explains How APC Mutations Induce Proliferative Abnormalities That Drive Colon Cancer Development

    Science.gov (United States)

    Boman, Bruce M.; Fields, Jeremy Z.

    2013-01-01

    APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT) that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs) at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside). WNT signaling, in contrast, is high at the bottom (where SCs reside) and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g., survivin) are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric). APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly proliferating cells) during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes. PMID:24224156

  19. Different land use intensities in grassland ecosystems drive ecology of microbial communities involved in nitrogen turnover in soil.

    Science.gov (United States)

    Meyer, Annabel; Focks, Andreas; Radl, Viviane; Keil, Daniel; Welzl, Gerhard; Schöning, Ingo; Boch, Steffen; Marhan, Sven; Kandeler, Ellen; Schloter, Michael

    2013-01-01

    Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions, which have been continuously treated for many years as intensely used meadows (IM), intensely used mown pastures (IP) and extensively used pastures (EP), respectively. The obtained data were linked to above ground biodiversity pattern as well as water extractable fractions of nitrogen and carbon in soil. Shifts in land use intensity changed plant community composition from systems dominated by s-strategists in extensive managed grasslands to c-strategist dominated communities in intensive managed grasslands. Along the different types of land use intensity, the availability of inorganic nitrogen regulated the abundance of bacterial and archaeal ammonia oxidizers. In contrast, the amount of dissolved organic nitrogen determined the abundance of denitrifiers (nirS and nirK). The high abundance of nifH carrying bacteria at intensive managed sites gave evidence that the amounts of substrates as energy source outcompete the high availability of inorganic nitrogen in these sites. Overall, we revealed that abundance and function of microorganisms involved in key processes of inorganic N cycling (nitrification, denitrification and N fixation) might be independently regulated by different abiotic and biotic factors in response to land use intensity.

  20. Different land use intensities in grassland ecosystems drive ecology of microbial communities involved in nitrogen turnover in soil.

    Directory of Open Access Journals (Sweden)

    Annabel Meyer

    Full Text Available Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions, which have been continuously treated for many years as intensely used meadows (IM, intensely used mown pastures (IP and extensively used pastures (EP, respectively. The obtained data were linked to above ground biodiversity pattern as well as water extractable fractions of nitrogen and carbon in soil. Shifts in land use intensity changed plant community composition from systems dominated by s-strategists in extensive managed grasslands to c-strategist dominated communities in intensive managed grasslands. Along the different types of land use intensity, the availability of inorganic nitrogen regulated the abundance of bacterial and archaeal ammonia oxidizers. In contrast, the amount of dissolved organic nitrogen determined the abundance of denitrifiers (nirS and nirK. The high abundance of nifH carrying bacteria at intensive managed sites gave evidence that the amounts of substrates as energy source outcompete the high availability of inorganic nitrogen in these sites. Overall, we revealed that abundance and function of microorganisms involved in key processes of inorganic N cycling (nitrification, denitrification and N fixation might be independently regulated by different abiotic and biotic factors in response to land use intensity.

  1. Different Land Use Intensities in Grassland Ecosystems Drive Ecology of Microbial Communities Involved in Nitrogen Turnover in Soil

    Science.gov (United States)

    Meyer, Annabel; Focks, Andreas; Radl, Viviane; Keil, Daniel; Welzl, Gerhard; Schöning, Ingo; Boch, Steffen; Marhan, Sven; Kandeler, Ellen; Schloter, Michael

    2013-01-01

    Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions, which have been continuously treated for many years as intensely used meadows (IM), intensely used mown pastures (IP) and extensively used pastures (EP), respectively. The obtained data were linked to above ground biodiversity pattern as well as water extractable fractions of nitrogen and carbon in soil. Shifts in land use intensity changed plant community composition from systems dominated by s-strategists in extensive managed grasslands to c-strategist dominated communities in intensive managed grasslands. Along the different types of land use intensity, the availability of inorganic nitrogen regulated the abundance of bacterial and archaeal ammonia oxidizers. In contrast, the amount of dissolved organic nitrogen determined the abundance of denitrifiers (nirS and nirK). The high abundance of nifH carrying bacteria at intensive managed sites gave evidence that the amounts of substrates as energy source outcompete the high availability of inorganic nitrogen in these sites. Overall, we revealed that abundance and function of microorganisms involved in key processes of inorganic N cycling (nitrification, denitrification and N fixation) might be independently regulated by different abiotic and biotic factors in response to land use intensity. PMID:24039974

  2. A liquid chromatography – tandem mass spectrometry method to measure a selected panel of uremic retention solutes derived from endogenous and colonic microbial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Loor, Henriette de; Poesen, Ruben [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); De Leger, Wout; Dehaen, Wim [KU Leuven – University of Leuven, Department of Chemistry, Division of Molecular Design and Synthesis, B-3000 Leuven (Belgium); Augustijns, Patrick [KU Leuven – University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Drug Delivery and Disposition, B-3000 Leuven (Belgium); Evenepoel, Pieter [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium); Meijers, Björn, E-mail: bjorn.meijers@uzleuven.be [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium)

    2016-09-14

    Chronic kidney disease (CKD) is associated with an increased risk of mortality and cardiovascular disease, which is, at least partly, mediated by the accumulation of so-called uremic retention solutes. Although there has been an increasing interest in the behavior of these solutes, derived from both the endogenous and colonic microbial metabolism, methods to simultaneously and accurately measure a broad panel of relevant uremic retention solutes remain scarce. We developed a highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. A high throughput sample preparation was used with extraction of analytes from 50 μl serum using Ostro plate technology. For most solutes, stable isotopes labelled metabolites were used as internal standards. Chromatography was achieved using an Acquity UPLC CSH Fluoro Phenyl column. The total run time was 8 min, the mobile phase was a gradient of 0.1% formic acid in Milli-Q water and pure methanol at a flow rate of 0.5 ml min{sup −1}. Detection was performed using a tandem mass spectrometer with alternated positive and negative electrospray ionization. Calibration curves were linear for all solutes. Precision was assessed according to the NCCLS EP5-T guideline, being below 15% for all metabolites. Mean recoveries were between 83 and 104% for all metabolites. The validated method was successfully applied in a cohort of 488 patients with CKD. We developed and validated a sensitive and robust UPLC-MS/MS method for quantification of 15 uremic retention solutes derived from endogenous and colonic microbial metabolism. This method allows for studying the behavior and relevance of these solutes in patients with CKD. - Highlights: • Simultaneous quantification of fifteen relevant uremic retention solutes. • Comprehensive validation, highly sensitive and high through-put LC-MSMS method. • Comparison of different blood tubes. • Freeze-thaw stability. • Successful implementation in a

  3. Colon cancer

    Science.gov (United States)

    Colorectal cancer; Cancer - colon; Rectal cancer; Cancer - rectum; Adenocarcinoma - colon; Colon - adenocarcinoma; Colon carcinoma ... eat may play a role in getting colon cancer. Colon cancer may be linked to a high-fat, ...

  4. New methods for determination of microbial adherence and colonization to bio material surface pre and post-irradiation treatment in cancer patients

    International Nuclear Information System (INIS)

    Shehata, M.M.K.K.

    2007-01-01

    Biomaterials are being used with increasing frequency in medical fields in the saving of patients' lives and enhancing the quality of life for many others.Colonization of biomaterials by some pathogenic microorganisms depends on their ability to grow and adhere to the solid surface which then allows microorganisms to from bio films in which they are protected from host defense mechanisms and antimicrobial chemotherapy. Adherence and colonization followed by biofilm formation has been implicated as a potential virulence factor of some pathogenic strains responsible for catheter related infections in immuno-compromised cancer patients. Adherence assay and quantitation of bio films of microorganisms isolated and identified from catheter associated urinary tract infections from bladder cancer patients was performed by spectrophotometric method, hydrophobicities of some tested strains were also evaluated by adhesion to p-xylene, MICs of various antibiotics for isolated strains in conjunction with plasmid profiles and algD gene responsible for biofilm formation of selected strains were determined before and after in-vitro exposure to test dose of 24.14 Gy gamma radiation in studying the role of radiotherapy on the microorganisms and their virulence and also enable the design for new approaches to the prevention of serious microbial infections by interfering with adhesion process

  5. Microbial DNA fingerprinting of human fingerprints: dynamic colonization of fingertip microflora challenges human host inferences for forensic purposes.

    Science.gov (United States)

    Tims, Sebastian; van Wamel, Willem; Endtz, Hubert P; van Belkum, Alex; Kayser, Manfred

    2010-09-01

    Human fingertip microflora is transferred to touched objects and may provide forensically relevant information on individual hosts, such as on geographic origins, if endogenous microbial skin species/strains would be retrievable from physical fingerprints and would carry geographically restricted DNA diversity. We tested the suitability of physical fingerprints for revealing human host information, with geographic inference as example, via microbial DNA fingerprinting. We showed that the transient exogenous fingertip microflora is frequently different from the resident endogenous bacteria of the same individuals. In only 54% of the experiments, the DNA analysis of the transient fingertip microflora allowed the detection of defined, but often not the major, elements of the resident microflora. Although we found microbial persistency in certain individuals, time-wise variation of transient and resident microflora within individuals was also observed when resampling fingerprints after 3 weeks. While microbial species differed considerably in their frequency spectrum between fingerprint samples from volunteers in Europe and southern Asia, there was no clear geographic distinction between Staphylococcus strains in a cluster analysis, although bacterial genotypes did not overlap between both continental regions. Our results, though limited in quantity, clearly demonstrate that the dynamic fingerprint microflora challenges human host inferences for forensic purposes including geographic ones. Overall, our results suggest that human fingerprint microflora is too dynamic to allow for forensic marker developments for retrieving human information.

  6. Impact of drinking water conditions and copper materials on downstream biofilm microbial communities and legionella pneumophila colonization

    Science.gov (United States)

    Legionella pneumophila, the medically important species within the genus Legionella, is a concern in engineered water systems. Its ability to amplify within free-living amoebae is well documented, but its interactions/ecology within the microbial community of drinking water biofi...

  7. Microbial DNA fingerprinting of human fingerprints: dynamic colonization of fingertip microflora challenges human host inferences for forensic purposes

    NARCIS (Netherlands)

    S. Tims (Sebastian); W.J.B. van Wamel (Willem); H.P. Endtz (Hubert); A.F. van Belkum (Alex); M.H. Kayser (Manfred)

    2009-01-01

    textabstractHuman fingertip microflora is transferred to touched objects and may provide forensically relevant information on individual hosts, such as on geographic origins, if endogenous microbial skin species/strains would be retrievable from physical fingerprints and would carry geographically

  8. Bacterial adaptation to the gut environment favors successful colonization: microbial and metabonomic characterization of a simplified microbiota mouse model.

    Science.gov (United States)

    Rezzonico, Enea; Mestdagh, Renaud; Delley, Michèle; Combremont, Séverine; Dumas, Marc-Emmanuel; Holmes, Elaine; Nicholson, Jeremy; Bibiloni, Rodrigo

    2011-01-01

    Rodent models harboring a simple yet functional human intestinal microbiota provide a valuable tool to study the relationships between mammals and their bacterial inhabitants. In this study, we aimed to develop a simplified gnotobiotic mouse model containing 10 easy-to-grow bacteria, readily available from culture repositories, and of known genome sequence, that overall reflect the dominant commensal bacterial makeup found in adult human feces. We observed that merely inoculating a mix of fresh bacterial cultures into ex-germ free mice did not guarantee a successful intestinal colonization of the entire bacterial set, as mice inoculated simultaneously with all strains only harbored 3 after 21 d. Therefore, several inoculation procedures were tested and levels of individual strains were quantified using molecular tools. Best results were obtained by inoculating single bacterial strains into individual animals followed by an interval of two weeks before allowing the animals to socialize to exchange their commensal microbes. Through this procedure, animals were colonized with almost the complete bacterial set (9/10). Differences in the intestinal composition were also reflected in the urine and plasma metabolic profiles, where changes in lipids, SCFA, and amino acids were observed. We conclude that adaptation of bacterial strains to the host's gut environment (mono-colonization) may predict a successful establishment of a more complex microbiota in rodents.

  9. Low iron availability in continuous in vitro colonic fermentations induces strong dysbiosis of the child gut microbial consortium and a decrease of main metabolites

    Science.gov (United States)

    Dostal, Alexandra; Fehlbaum, Sophie; Chassard, Christophe; Zimmermann, Michael Bruce; Lacroix, Christophe

    2012-01-01

    Iron (Fe) deficiency affects an estimated 2 billion people worldwide and Fe supplements are a common corrective strategy. The impact of Fe deficiency and Fe supplementation on the complex microbial community of the child gut was studied using in vitro colonic fermentation models inoculated with immobilized fecal microbiota. Chyme media (all Fe chelated by 2,2’-dipyridyl to 26.5 mg Fe L-1) mimicking Fe deficiency and supplementation were continuously fermented. Fermentation effluent samples were analyzed daily on the microbial composition and metabolites by qPCR, 16S rRNA gene 454-pyrosequencing and HPLC. Low Fe conditions (1.56 mg Fe L-1) significantly decreased acetate concentrations and subsequent Fe supplementation (26.5 mg Fe L-1) restored acetate production. High Fe following normal Fe conditions had no impact on the gut microbiota composition and metabolic activity. During very low Fe conditions (0 . 9 m g F e L-1 or Fe chelated b y 2,2’-dipyridyl), a decrease of Roseburia spp./Eubacterium rectale, Clostridium Cluster IV members and Bacteroides spp. was observed while Lactobacillus spp. and Enterobacteriaceae increased consistent with a decrease of butyrate (-84%) and propionate (-55%). The strong dysbiosis of the gut microbiota together with decrease of main gut microbiota metabolites observed with very low iron conditions could weaken the barrier effect of the microbiota and negatively impact gut health. PMID:22845175

  10. Effects of correcting in situ ruminal microbial colonization of feed particles on the relationship between ruminally undegraded and intestinally digested crude protein in concentrate feeds.

    Science.gov (United States)

    González, Javier; Mouhbi, Rabiaa; Guevara-González, Jesús Alberto; Arroyo, José María

    2018-02-01

    In situ estimates of ruminally undegraded protein (RUP) and intestinally digested protein (IDP) of ten concentrates, uncorrected or corrected for the ruminal microbial colonization, were used to examine the effects of this correction on the relationship between IDP and RUP values. Both variables were established for three rumen and duodenum cannulated wethers using 15 N labeling-techniques and considering measured rates of ruminal particle comminution (k c ) and outflow (k p ). A covariance analysis showed that the close relationship found between both variables (IDP = -0.0132 ± 0.00679 + 0.776 ± 0.0002 RUP; n = 60; P content in concentrates and industrial by-products can be predicted from RUP values, thus avoiding the laborious and complex procedure of determining intestinal digestibility; however, a larger sample of feeds is necessary to achieve more accurate predictions. The lack of influence of the correction for microbial contamination on the prediction observed in the present study increases the data available for this prediction. However, only the use of corrected values may provide an accurate evaluation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Low iron availability in continuous in vitro colonic fermentations induces strong dysbiosis of the child gut microbial consortium and a decrease in main metabolites.

    Science.gov (United States)

    Dostal, Alexandra; Fehlbaum, Sophie; Chassard, Christophe; Zimmermann, Michael B; Lacroix, Christophe

    2013-01-01

    Iron (Fe) deficiency affects an estimated 2 billion people worldwide, and Fe supplements are a common corrective strategy. The impact of Fe deficiency and Fe supplementation on the complex microbial community of the child gut was studied using in vitro colonic fermentation models inoculated with immobilized fecal microbiota. Chyme media (all Fe chelated by 2,2'-dipyridyl to 26.5 mg Fe L(-1) ) mimicking Fe deficiency and supplementation were continuously fermented. Fermentation effluent samples were analyzed daily on the microbial composition and metabolites by quantitative PCR, 16S rRNA gene 454-pyrosequencing, and HPLC. Low Fe conditions (1.56 mg Fe L(-1) ) significantly decreased acetate concentrations, and subsequent Fe supplementation (26.5 mg Fe L(-1) ) restored acetate production. High Fe following normal Fe conditions had no impact on the gut microbiota composition and metabolic activity. During very low Fe conditions (0.9 mg Fe L(-1) or Fe chelated by 2,2'-dipyridyl), a decrease in Roseburia spp./Eubacterium rectale, Clostridium Cluster IV members and Bacteroides spp. was observed, while Lactobacillus spp. and Enterobacteriaceae increased consistent with a decrease in butyrate (-84%) and propionate (-55%). The strong dysbiosis of the gut microbiota together with decrease in main gut microbiota metabolites observed with very low iron conditions could weaken the barrier effect of the microbiota and negatively impact gut health. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  12. Soil microbial communities drive the resistance of ecosystem multifunctionality to global change in drylands across the globe.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Eldridge, David J; Ochoa, Victoria; Gozalo, Beatriz; Singh, Brajesh K; Maestre, Fernando T

    2017-10-01

    The relationship between soil microbial communities and the resistance of multiple ecosystem functions linked to C, N and P cycling (multifunctionality resistance) to global change has never been assessed globally in natural ecosystems. We collected soils from 59 dryland ecosystems worldwide to investigate the importance of microbial communities as predictor of multifunctionality resistance to climate change and nitrogen fertilisation. Multifunctionality had a lower resistance to wetting-drying cycles than to warming or N deposition. Multifunctionality resistance was regulated by changes in microbial composition (relative abundance of phylotypes) but not by richness, total abundance of fungi and bacteria or the fungal: bacterial ratio. Our results suggest that positive effects of particular microbial taxa on multifunctionality resistance could potentially be controlled by altering soil pH. Together, our work demonstrates strong links between microbial community composition and multifunctionality resistance in dryland soils from six continents, and provides insights into the importance of microbial community composition for buffering effects of global change in drylands worldwide. © 2017 John Wiley & Sons Ltd/CNRS.

  13. Intestinal microbial dysbiosis and colonic epithelial cell hyperproliferation by dietary α-mangostin is independent of mouse strain.

    Science.gov (United States)

    Gutierrez-Orozco, Fabiola; Thomas-Ahner, Jennifer M; Galley, Jeffrey D; Bailey, Michael T; Clinton, Steven K; Lesinski, Gregory B; Failla, Mark L

    2015-01-22

    Beverages and supplements prepared from mangosteen fruit are claimed to support gut health and immunity, despite the absence of supporting evidence from clinical trials. We recently reported that α-mangostin (α-MG), the most abundant xanthone in mangosteen fruit, altered the intestinal microbiome, promoted dysbiosis, and exacerbated colitis in C57BL/6J mice. The objective of this study was to determine whether induction of dysbiosis by dietary α-MG is limited to the C57BL/6J strain or represents a more generic response to chronic intake of the xanthone on the gut microbiota of mice. C3H, Balb/c, Nude FoxN1nu, and C57BL/6J mice, each demonstrating unique microbiomes, were fed standard diet or diet containing 0.1% α-MG for four weeks. Dietary α-MG significantly altered the cecal and colonic microbiota in all four strains of mice, promoting a reduction in generally assumed beneficial bacterial groups while increasing the abundance of pathogenic bacteria. Consumption of α-MG was associated with reduced abundance of Firmicutes and increased abundance of Proteobacteria. The abundance of Lachnospiraceae, Ruminococcaceae, and Lactobacillaceae was reduced in α-MG-fed mice, while that of Enterobacteriaceae and Enterococcaceae was increased. Dietary α-MG also was associated with increased proliferation of colonic epithelial cells, infiltration of immune cells, infiltration of immune cells and increased fluid content in stool. These results suggest that ingestion of pharmacologic doses of xanthones in mangosteen-containing supplements may adversely alter the gut microbiota and should be used with caution.

  14. Intestinal Microbial Dysbiosis and Colonic Epithelial Cell Hyperproliferation by Dietary α-Mangostin is Independent of Mouse Strain

    Directory of Open Access Journals (Sweden)

    Fabiola Gutierrez-Orozco

    2015-01-01

    Full Text Available Beverages and supplements prepared from mangosteen fruit are claimed to support gut health and immunity, despite the absence of supporting evidence from clinical trials. We recently reported that α-mangostin (α-MG, the most abundant xanthone in mangosteen fruit, altered the intestinal microbiome, promoted dysbiosis, and exacerbated colitis in C57BL/6J mice. The objective of this study was to determine whether induction of dysbiosis by dietary α-MG is limited to the C57BL/6J strain or represents a more generic response to chronic intake of the xanthone on the gut microbiota of mice. C3H, Balb/c, Nude FoxN1nu, and C57BL/6J mice, each demonstrating unique microbiomes, were fed standard diet or diet containing 0.1% α-MG for four weeks. Dietary α-MG significantly altered the cecal and colonic microbiota in all four strains of mice, promoting a reduction in generally assumed beneficial bacterial groups while increasing the abundance of pathogenic bacteria. Consumption of α-MG was associated with reduced abundance of Firmicutes and increased abundance of Proteobacteria. The abundance of Lachnospiraceae, Ruminococcaceae, and Lactobacillaceae was reduced in α-MG-fed mice, while that of Enterobacteriaceae and Enterococcaceae was increased. Dietary α-MG also was associated with increased proliferation of colonic epithelial cells, infiltration of immune cells, infiltration of immune cells and increased fluid content in stool. These results suggest that ingestion of pharmacologic doses of xanthones in mangosteen-containing supplements may adversely alter the gut microbiota and should be used with caution.

  15. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter

    Directory of Open Access Journals (Sweden)

    Zachary L Rinkes

    2013-09-01

    Full Text Available Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (< 10% mass loss, mid- (10-40% mass loss, and late (> 40% mass loss decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood < maple < maple-oak mixture < oak. In the field, mass loss was minimal (< 10% over the first 50 days (January-February, even for labile litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab

  16. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter.

    Science.gov (United States)

    Rinkes, Zachary L; Sinsabaugh, Robert L; Moorhead, Daryl L; Grandy, A Stuart; Weintraub, Michael N

    2013-01-01

    Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (40% mass loss) decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C) ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N) accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab conditions.

  17. Different flour microbial communities drive to sourdoughs characterized by diverse bacterial strains and free amino acid profiles

    Directory of Open Access Journals (Sweden)

    GIUSEPPE CELANO

    2016-11-01

    Full Text Available This work aimed to investigate whether different microbial assemblies in flour may influence the microbiological and biochemical characteristics of traditional sourdough. To reach this purpose, members of lactic acid bacteria, enterobacteria, and yeasts were isolated from durum wheat flour. Secondly, the isolated microorganisms (Pediococcus pentosaceus, Saccharomyces cerevisiae, Pantoea agglomerans, and Escherichia hermanni were inoculated in doughs prepared with irradiated flour (gamma rays at 10 kGy, so that eight different microbial assemblies were obtained. Two non-inoculated controls were prepared, one of which (C-IF using irradiated flour and the other (C using non-irradiated flour.As shown by plate counts, irradiation of flour caused total inactivation of yeasts and a decrease of all the other microbial populations. However acidification occurred also in the dough C-IF, due to metabolic activity of P. pentosaceus that had survived irradiation. After six fermentations, P. pentosaceus was the dominant lactic acid bacterium species in all the sourdoughs produced with irradiated flour (IF. Yet, IF-based sourdoughs broadly differed from each other in terms of strains of P. pentosaceus, probably due to the different microorganisms initially inoculated. Quantitative and qualitative differences of free amino acids concentration were found among the sourdoughs, possibly because of different microbial communities. In addition, as shown by culture-independent analysis (16S metagenetics, irradiation of flour lowered and modified microbial diversity of sourdough ecosystem.

  18. Strain-resolved microbial community proteomics reveals simultaneous aerobic and anaerobic function during gastrointestinal tract colonization of a preterm infant

    Directory of Open Access Journals (Sweden)

    Brandon eBrooks

    2015-07-01

    Full Text Available While there has been growing interest in the gut microbiome in recent years, it remains unclear whether closely related species and strains have similar or distinct functional roles and if organisms capable of both aerobic and anaerobic growth do so simultaneously. To investigate these questions, we implemented a high-throughput mass spectrometry-based proteomics approach to identify proteins in fecal samples collected on days of life 13-21 from an infant born at 28 weeks gestation. No prior studies have coupled strain-resolved community metagenomics to proteomics for such a purpose. Sequences were manually curated to resolve the genomes of two strains of Citrobacter that were present during the later stage of colonization. Proteome extracts from fecal samples were processed via a nano-2D-LC-MS/MS and peptides were identified based on information predicted from the genome sequences for the dominant organisms, Serratia and the two Citrobacter strains. These organisms are facultative anaerobes, and proteomic information indicates the utilization of both aerobic and anaerobic metabolisms throughout the time series. This may indicate growth in distinct niches within the gastrointestinal tract. We uncovered differences in the physiology of coexisting Citrobacter strains, including differences in motility and chemotaxis functions. Additionally, for both Citrobacter strains we resolved a community-essential role in vitamin metabolism and a predominant role in propionate production. Finally, in this case study we detected differences between genome abundance and activity levels for the dominant populations. This underlines the value in layering proteomic information over genetic potential.

  19. Weathering of post-impact hydrothermal deposits from the Haughton impact structure: implications for microbial colonization and biosignature preservation.

    Science.gov (United States)

    Izawa, M R M; Banerjee, Neil R; Osinski, G R; Flemming, R L; Parnell, J; Cockell, C S

    2011-01-01

    Meteorite impacts are among the very few processes common to all planetary bodies with solid surfaces. Among the effects of impact on water-bearing targets is the formation of post-impact hydrothermal systems and associated mineral deposits. The Haughton impact structure (Devon Island, Nunavut, Canada, 75.2 °N, 89.5 °W) hosts a variety of hydrothermal mineral deposits that preserve assemblages of primary hydrothermal minerals commonly associated with secondary oxidative/hydrous weathering products. Hydrothermal mineral deposits at Haughton include intra-breccia calcite-marcasite vugs, small intra-breccia calcite or quartz vugs, intra-breccia gypsum megacryst vugs, hydrothermal pipe structures and associated surface "gossans," banded Fe-oxyhydroxide deposits, and calcite and quartz veins and coatings in shattered target rocks. Of particular importance are sulfide-rich deposits and their associated assemblage of weathering products. Hydrothermal mineral assemblages were characterized structurally, texturally, and geochemically with X-ray diffraction, micro X-ray diffraction, optical and electron microscopy, and inductively coupled plasma atomic emission spectroscopy. Primary sulfides (marcasite and pyrite) are commonly associated with alteration minerals, including jarosite (K,Na,H(3)O)Fe(3)(SO(4))(2)(OH)(6), rozenite FeSO(4)·4(H(2)O), copiapite (Fe,Mg)Fe(4)(SO(4))(6)(OH)(2)·20(H(2)O), fibroferrite Fe(SO(4))(OH)·5(H(2)O), melanterite FeSO(4)·7(H(2)O), szomolnokite FeSO(4)·H(2)O, goethite α-FeO(OH), lepidocrocite γ-FeO(OH) and ferrihydrite Fe(2)O(3)·0.5(H(2)O). These alteration assemblages are consistent with geochemical conditions that were locally very different from the predominantly circumneutral, carbonate-buffered environment at Haughton. Mineral assemblages associated with primary hydrothermal activity, and the weathering products of such deposits, provide constraints on possible microbial activity in the post-impact environment. The initial period of

  20. Host Ecology Rather Than Host Phylogeny Drives Amphibian Skin Microbial Community Structure in the Biodiversity Hotspot of Madagascar

    OpenAIRE

    Bletz, Molly C.; Archer, Holly; Harris, Reid N.; McKenzie, Valerie J.; Rabemananjara, Falitiana C. E.; Rakotoarison, Andolalao; Vences, Miguel

    2017-01-01

    Host-associated microbiotas of vertebrates are diverse and complex communities that contribute to host health. In particular, for amphibians, cutaneous microbial communities likely play a significant role in pathogen defense; however, our ecological understanding of these communities is still in its infancy. Here, we take advantage of the fully endemic and locally species-rich amphibian fauna of Madagascar to investigate the factors structuring amphibian skin microbiota on a large scale. Usin...

  1. Accelerated decay rates drive soil organic matter persistence and storage in temperate forests via greater mineral stabilization of microbial residues.

    Science.gov (United States)

    Phillips, R.; Craig, M.; Turner, B. L.; Liang, C.

    2017-12-01

    Climate predicts soil organic matter (SOM) stocks at the global scale, yet controls on SOM stocks at finer spatial scales are still debated. A current hypothesis predicts that carbon (C) and nitrogen (N) storage in soils should be greater when decomposition is slow owing to microbial competition for nutrients or the recalcitrance of organic substrates (hereafter the `slow decay' hypothesis). An alternative hypothesis predicts that soil C and N storage should be greater in soils with rapid decomposition, owing to the accelerated production of microbial residues and their stabilization on soil minerals (hereafter the `stabilization hypothesis'). To test these alternative hypotheses, we quantified soil C and N to 1-m depth in temperate forests across the Eastern and Midwestern US that varied in their biotic, climatic, and edaphic properties. At each site, we sampled (1) soils dominated by arbuscular mycorrhizal (AM) tree species, which typically have fast decay rates and accelerated N cycling, (2) soils dominated by ectomycorrhizal (ECM) tree species, which generally have slow decay rates and slow N cycling, and (3) soils supporting both AM and ECM trees. To the extent that trees and theor associated microbes reflect and reinforce soil conditions, support for the slow decay hypothesis would be greater SOM storage in ECM soils, whereas support for the stabilization hypothesis would be greater SOM storage in AM soils. We found support for both hypotheses, as slow decomposition in ECM soils increased C and N storage in topsoil, whereas fast decomposition in AM soils increased C and N storage in subsoil. However, at all sites we found 57% greater total C and N storage in the entire profile in AM- soils (P stabilization hypothesis. Amino sugar biomarkers (an indicator of microbial necromass) and particle size fractionation revealed that the greater SOM storage in AM soils was driven by an accumulation of microbial residues on clay minerals and metal oxides. Taken together

  2. Timing of global regression and microbial bloom linked with the Permian-Triassic boundary mass extinction: implications for driving mechanisms.

    Science.gov (United States)

    Baresel, Björn; Bucher, Hugo; Bagherpour, Borhan; Brosse, Morgane; Guodun, Kuang; Schaltegger, Urs

    2017-03-06

    New high-resolution U-Pb dates indicate a duration of 89 ± 38 kyr for the Permian hiatus and of 14 ± 57 kyr for the overlying Triassic microbial limestone in shallow water settings of the Nanpanjiang Basin, South China. The age and duration of the hiatus coincides with the Permian-Triassic boundary (PTB) and the extinction interval in the Meishan Global Stratotype Section and Point, and strongly supports a glacio-eustatic regression, which best explains the genesis of the worldwide hiatus straddling the PTB in shallow water records. In adjacent deep marine troughs, rates of sediment accumulation display a six-fold decrease across the PTB compatible with a dryer and cooler climate as indicated by terrestrial plants. Our model of the Permian-Triassic boundary mass extinction (PTBME) hinges on the synchronicity of the hiatus with the onset of the Siberian Traps volcanism. This early eruptive phase released sulfur-rich volatiles into the stratosphere, thus simultaneously eliciting a short-lived ice age responsible for the global regression and a brief but intense acidification. Abrupt cooling, shrunk habitats on shelves and acidification may all have synergistically triggered the PTBME. Subsequently, the build-up of volcanic CO 2 induced a transient cool climate whose early phase saw the deposition of the microbial limestone.

  3. Microbial ecology and adaptation in cystic fibrosis airways

    DEFF Research Database (Denmark)

    Yang, Lei; Jelsbak, Lars; Molin, Søren

    2011-01-01

    Chronic infections in the respiratory tracts of cystic fibrosis (CF) patients are important to investigate, both from medical and from fundamental ecological points of view. Cystic fibrosis respiratory tracts can be described as natural environments harbouring persisting microbial communities...... constitute the selective forces that drive the evolution of the microbes after they migrate from the outer environment to human airways. Pseudomonas aeruginosa adapts to the new environment through genetic changes and exhibits a special lifestyle in chronic CF airways. Understanding the persistent...... colonization of microbial pathogens in CF patients in the context of ecology and evolution will expand our knowledge of the pathogenesis of chronic infections and improve therapeutic strategies....

  4. Belowground Carbon Allocation and Plant-Microbial Interactions Drive Resistance and Resilience of Mountain Grassland Communities to Drought

    Science.gov (United States)

    Karlowsky, S.; Augusti, A.; Ingrisch, J.; Hasibeder, R.; Lavorel, S.; Bahn, M.; Gleixner, G.

    2016-12-01

    Belowground carbon allocation (BCA) and plant-microbial interactions are crucial for the functioning of terrestrial ecosystems. Recent research suggests that extreme events can have severe effects on these processes but it is unknown how land use intensity potentially modifies their responses. We studied the resistance and resilience of mountain grassland communities to prolonged drought and investigated the role of plant C allocation and soil microbial communities in mediating drought resistance and immediate recovery. In a common garden experiment we exposed monoliths from an abandoned grassland and a hay meadow to an early summer drought. Two independent 13C pulse labeling experiments were conducted, the first during peak drought and the second during the recovery phase. The 13C incorporation was analyzed in above- and belowground plant parts and in phospho- and neutral lipid fatty acids of soil microorganisms. In addition, a 15N label was added at the rewetting to determine plant N uptake. We found that C uptake, BCA and C transfer to soil microorganisms were less strongly reduced by drought in the abandoned grassland than in the meadow. Moreover, drought induced an increase of arbuscular mycorrhiza fungi (AMF) marker in the abandoned grassland. Nevertheless, C uptake and related parameters were quickly recovered and N uptake increased in the meadow during recovery. Unexpectedly, AMF and their C uptake were generally reduced during recovery, while bacteria increased and quickly recovered C uptake, particularly in the meadow. Our results showed a negative relation between high resistance and fast recovery. The more resistant abandoned grassland plant communities seemed to invest more C below ground and into interactions with AMF during drought, likely to access water through their hyphal network. Conversely, meadow communities invested more C from recent photosynthesis into bacterial communities during recovery, obviously to gain more nutrients for regrowth

  5. Timing of global regression and microbial bloom linked with the Permian-Triassic boundary mass extinction: implications for driving mechanisms

    Science.gov (United States)

    Baresel, Bjoern; Bucher, Hugo; Bagherpour, Borhan; Brosse, Morgane; Guodun, Kuang; Schaltegger, Urs

    2017-04-01

    High-precision U-Pb dating of single-zircon crystals by chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) is applied to volcanic beds that are intercalated in sedimentary sequences across the Permian-Triassic boundary (PTB). By assuming that the zircon crystallization age closely approximate that of the volcanic eruption and subsequent deposition, U-Pb zircon geochronology is the preferred approach for dating abiotic and biotic events, such as the formational PTB and the Permian-Triassic boundary mass extinction (PTBME). We will present new U-Pb zircon dates for a series of volcanic ash beds in shallow-marine Permian-Triassic sections in the Nanpanjiang Basin, South China. These high-resolution U-Pb dates indicate a duration of 90 ± 38 kyr for the Permian sedimentary hiatus and a duration of 13 ± 57 kyr for the overlying Triassic microbial limestone in the shallow water settings of the Nanpanjiang pull apart Basin. The age and duration of the hiatus coincides with the formational PTB and the extinction interval in the Meishan Global Stratotype Section and Point, thus strongly supporting a glacio-eustatic regression, which best explains the genesis of the worldwide hiatus straddling the PTB in shallow water records. In adjacent deep marine troughs, rates of sediment accumulation display a six-fold decrease across the PTB compatible with a dryer and cooler climate during the Griesbachian as indicated by terrestrial plants. Our model of the PTBME hinges on the synchronicity of the hiatus with the onset of the Siberian Traps volcanism. This early eruptive phase likely released sulfur-rich volatiles into the stratosphere, thus simultaneously eliciting a short-lived ice age responsible for the global regression and a brief but intense acidification. Abrupt cooling, shrunk habitats on shelves and acidification may all have synergistically triggered the PTBME. Subsequently, the build-up of volcanic CO2 induced this transient cool

  6. Barcoded pyrosequencing analysis of the microbial community in a simulator of the human gastrointestinal tract showed a colon region-specific microbiota modulation for two plant-derived polysaccharide blends.

    Science.gov (United States)

    Marzorati, Massimo; Maignien, Lois; Verhelst, An; Luta, Gabriela; Sinnott, Robert; Kerckhof, Frederiek Maarten; Boon, Nico; Van de Wiele, Tom; Possemiers, Sam

    2013-02-01

    The combination of a Simulator of the Human Intestinal Microbial Ecosystem with ad hoc molecular techniques (i.e. pyrosequencing, denaturing gradient gel electrophoresis and quantitative PCR) allowed an evaluation of the extent to which two plant polysaccharide supplements could modify a complex gut microbial community. The presence of Aloe vera gel powder and algae extract in product B as compared to the standard blend (product A) improved its fermentation along the entire simulated colon. The potential extended effect of product B in the simulated distal colon, as compared to product A, was confirmed by: (i) the separate clustering of the samples before and after the treatment in the phylogenetic-based dendrogram and OTU-based PCoA plot only for product B; (ii) a higher richness estimator (+33 vs. -36 % of product A); and (iii) a higher dynamic parameter (21 vs. 13 %). These data show that the combination of well designed in vitro simulators with barcoded pyrosequencing is a powerful tool for characterizing changes occurring in the gut microbiota following a treatment. However, for the quantification of low-abundance species-of interest because of their relationship to potential positive health effects (i.e. bifidobacteria or lactobacilli)-conventional molecular ecological approaches, such as PCR-DGGE and qPCR, still remain a very useful complementary tool.

  7. PRODUCTION UNDER CONTROLLED CONDITIONS OF “CASU MARZU” CHEESE: EFFECT OF THE Piophila Casei COLONIZATION ON MICROBIAL AND CHEMICAL COMPOSITION OF THE CHEESES

    Directory of Open Access Journals (Sweden)

    M Coinu

    2013-02-01

    Full Text Available The aim of the present study was to evaluate the effect of the Piophila casei colonization under controlled conditions on “casu marzu”, a typical Sardinian sheep milk cheese. Three batches of two different kind of cheese (PO, holed paste and PC, firm paste were produced in duplicate (test and control. Test cheeses were exposed to the Piophila casei colonization in a conditioned store room, while control cheeses were suitably protected. All the samples were analyzed at 0, 10, 30, 60 and 90 days from the production. The pH and aw, the chemical composition and the microbiological parameters (food safety and process hygiene criteria were determined. The colonization was unhomogeneous between the batches: PO cheeses were more easily colonized and showed more intense proteolysis and lipolysis respect to PC cheeses. The microbiological parameters were strongly affected by the experimental process conditions. The authors discuss about the opportunity of a controlled production of “casu marzu” and the implications to the health of consumers.

  8. Analysis of microbial taxonomical groups present in maize stalks suppressive to colonization by toxigenic Fusarium spp.: A strategy for the identification of potential antagonists

    NARCIS (Netherlands)

    Köhl, J.; Lombaers-van der Plas, C.H.; Moretti, A.; Bandyopadhyay, R.; Somma, S.; Kastelein, P.

    2015-01-01

    Pink ear rot of maize caused by Fusarium verticillioides, Fusariumproliferatum and Fusariumgraminearumcan lead to severe yield losses and contamination of grain with a range of mycotoxins. Maize stalks colonized by Fusarium spp. are the main primary inoculum source for Fusarium incited epidemics in

  9. Colonic transit time is related to bacterial metabolism and mucosal turnover in the human gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    Little is known about how colonic transit time relates to human colonic metabolism, and its importance for host health, although stool consistency, a proxy for colonic transit time, has recently been negatively associated with gut microbial richness. To address the relationships between colonic t...... imply a healthy gut microbial ecosystem and points at colonic transit time as a highly important factor to consider in microbiome and metabolomics studies.......Little is known about how colonic transit time relates to human colonic metabolism, and its importance for host health, although stool consistency, a proxy for colonic transit time, has recently been negatively associated with gut microbial richness. To address the relationships between colonic...... transit time and the gut microbial composition and metabolism, we assessed the colonic transit time of 98 subjects using radiopaque markers, and profiled their gut microbiota by16S rRNA gene sequencing and their urine metabolome by ultra performance liquid chromatography mass spectrometry. Based...

  10. COMPOSITION AND METHOD FOR CONTROLLING MICROBIAL ADHESION AND BIOFILM FORMATION OF SURFACES

    DEFF Research Database (Denmark)

    2003-01-01

    The present invention describes how coating of surfaces with an extract, particularly a fish extract, can significantly reduce microbial adhesion, attachment, colonization and biofilm formation on surfaces. Such reduction of microbial adherence, attachment and colonization will be applicable...

  11. Colon interposition

    International Nuclear Information System (INIS)

    Isolauri, J.; Tampere Univ. Central Hospital; Paakkala, T.; Arajaervi, P.; Markkula, H.

    1987-01-01

    Colon interposition was carried out in 12 patients with oesophageal carcinoma and on 38 patients with benign oesophageal disease an average of 71 months before the radiographic examination. Various ischaemic changes including 'jejunization', loss of haustration and stricture formation were observed in 15 cases. In 12 patients one or several diverticula were seen in the colon graft. Reflux was observed in 17 cases in supine position. Double contrast technique in the examination of interposed colon is recommended. (orig.)

  12. Colonic lipoma

    International Nuclear Information System (INIS)

    Siddiqui, M.S.; Khatri, A.R.; Quraishy, M.S.; Fatima, L.; Muzaffar, S.

    2003-01-01

    Lipoma of the colon is rare and may lead to intestinal obstruct. We have presented two cases of colonic lipoma. Both were elderly females, one presented with diarrhea and the other with sub-acute intestinal obstruction. After colonoscopy surgical removal was done. Histopathology revealed lipoma. (author)

  13. Colonic angiodysplasia

    International Nuclear Information System (INIS)

    Vallee, C.; Legmann, P.; Garnier, T.; Levesque, M.

    1984-01-01

    The main clinical, endoscopic and radiographic findings in thirty documented cases of colonic angiodysplasia or vacular ectasia are described. We emphasise the association with colonic diverticulosis and cardiovascular pathology, describe the histological changes, summarize the present physiopathological hypothesis, and consider the various therapeutic approaches. (orig.)

  14. Colonic locomotion

    NARCIS (Netherlands)

    Dodou, D.

    2006-01-01

    The most effective screening method for colonic cancer is colonoscopy. However, colonoscopy cannot be easily embraced by the population because of the related pain intensity. Robotic devices that pull themselves forward through the colon are a possible alternative. The main challenge for such

  15. AFM study of microbial colonization and its deleterious effect on 304 stainless steel by Pseudomonas NCIMB 2021 and Desulfovibrio desulfuricans in simulated seawater

    International Nuclear Information System (INIS)

    Yuan, S.J.; Pehkonen, S.O.

    2009-01-01

    The biofilm colonization dynamics of Pseudomonas NCIMB 2021 and Desulfovibrio desulfuricans (ATCC 27774) on 304 stainless steels (304 SS) was evaluated using atomic force microscopy (AFM) in simulated seawater-based media under aerobic and anaerobic conditions. Results showed that the biofilm formed on the coupon surface by the two strains of bacteria increased in the coverage, heterogeneity and thickness with exposure time, thus resulting in the deterioration of the steel substratum underneath the biofilm in the form of pitting corrosion. The depth of pits induced by D. desulfuricans was larger than that by Pseudomonas NCIMB 2021, which was mainly attributed to the enhanced corrosion of 304 SS coupons by the biogenic sulfide ions, as revealed by the results of X-ray photoelectron spectroscopy (XPS) and Tafel polarization curves. AFM was also used to determine cell attachment/detachment processes of the Pseudomonas and D. desulfuricans bacteria on the coupon surface by quantifying the tip-cell interaction forces. The interactive forces between the tip and the bacterial cell surface were considerably smaller than those between the tip and the cell-cell interface due to the accumulation of extra-cellular polymeric substances (EPS) for both strains. Furthermore, the adhesion forces over the Pseudomonas cells were verified to be more attractive than those of D. desulfuricans due to the former being a slime-producer.

  16. Colon neoplasm

    International Nuclear Information System (INIS)

    Kimura F, K.

    1991-01-01

    The main aspects of colon neoplasms are described, including several factors that predispose the disease, the occurrence, the main biomedical radiography and the evaluation after the surgery. (C.G.C.)

  17. Synthesis, spectroscopic properties, molecular docking, anti-colon cancer and anti-microbial studies of some novel metal complexes for 2-amino-4-phenylthiazole derivative

    Science.gov (United States)

    Al-Harbi, Sami A.; Bashandy, Mahmoud S.; Al-Saidi, Hammed M.; Emara, Adel A. A.; Mousa, Tarek A. A.

    2015-06-01

    This article describes the synthesis of novel bidentate Schiff base (H2L) from condensation of 2-amino-4-phenylthiazole (APT) with 4,6-diacetylresorcinol (DAR) in the molar ratio 2:1. We studied interaction of ligand (H2L) with transition metal ions such as Cr(III), Fe(III), Cu(II), Zn(II) and Cd(II). The ligand (H2L) has two bidentate sets of (N-O) units which can coordinate with two metal ions to afford novel binuclear metal complexes. The directions of coordinate bonds are from nitrogen atoms of azomethine groups and oxygen atoms of the phenolic groups. Structures of the newly synthesized complexes were confirmed by elemental analysis, IR, UV, 1H NMR, ESR, TGA and mass spectral data. All of the newly synthesized complexes were evaluated for their antibacterial and anti-fungal activities. They were also evaluated for their in vitro anticancer activity against human colon carcinoma cells (HCT-116) and mammalian cells of African green monkey kidney (VERO). The Cu(II) complex with selectivity index (S.I.) = 21.26 exhibited better activity than methotrexate (MTX) as a reference drug with S.I. value = 13.30, while Zn(II) complex with S.I. value = 10.24 was found to be nearly as active as MTX. Molecular docking studies further helped in understanding the mode of action of the compounds through their various interactions with active sites of dihydrofolate reductase (DHFR) enzyme. The observed activity of Fe(III) and Cu(II) complexes gave rise to the conclusion that they might exert their action through inhibition of the DHFR enzyme.

  18. Microbial ecology and biogeochemistry of continental Antarctic soils

    Directory of Open Access Journals (Sweden)

    Don A Cowan

    2014-04-01

    Full Text Available The Antarctica Dry Valleys are regarded as the coldest hyperarid desert system on Earth. While a wide variety of environmental stressors including very low minimum temperatures, frequent freeze-thaw cycles and low water availability impose severe limitations to life, suitable niches for abundant microbial colonization exist. Antarctic desert soils contain much higher levels of microbial diversity than previously thought. Edaphic niches, including cryptic and refuge habitats, microbial mats and permafrost soils all harbour microbial communities which drive key biogeochemical cycling processes. For example, lithobionts (hypoliths and endoliths possess a genetic capacity for nitrogen and carbon cycling, polymer degradation and other system processes. Nitrogen fixation rates of hypoliths, as assessed through acetylene reduction assays, suggest that these communities are a significant input source for nitrogen into these oligotrophic soils. Here we review aspects of microbial diversity in Antarctic soils with an emphasis on functionality and capacity. We assess current knowledge regarding adaptations to Antarctic soil environments and highlight the current threats to Antarctic desert soil communities.

  19. Microbial ecology and biogeochemistry of continental Antarctic soils.

    Science.gov (United States)

    Cowan, Don A; Makhalanyane, Thulani P; Dennis, Paul G; Hopkins, David W

    2014-01-01

    The Antarctica Dry Valleys are regarded as the coldest hyperarid desert system on Earth. While a wide variety of environmental stressors including very low minimum temperatures, frequent freeze-thaw cycles and low water availability impose severe limitations to life, suitable niches for abundant microbial colonization exist. Antarctic desert soils contain much higher levels of microbial diversity than previously thought. Edaphic niches, including cryptic and refuge habitats, microbial mats and permafrost soils all harbor microbial communities which drive key biogeochemical cycling processes. For example, lithobionts (hypoliths and endoliths) possess a genetic capacity for nitrogen and carbon cycling, polymer degradation, and other system processes. Nitrogen fixation rates of hypoliths, as assessed through acetylene reduction assays, suggest that these communities are a significant input source for nitrogen into these oligotrophic soils. Here we review aspects of microbial diversity in Antarctic soils with an emphasis on functionality and capacity. We assess current knowledge regarding adaptations to Antarctic soil environments and highlight the current threats to Antarctic desert soil communities.

  20. Insights into Feast-Famine polyhydroxyalkanoate (PHA)-producer selection: Microbial community succession, relationships with system function and underlying driving forces.

    Science.gov (United States)

    Huang, Long; Chen, Zhiqiang; Wen, Qinxue; Zhao, Lizhi; Lee, Duu-Jong; Yang, Lian; Wang, Yao

    2017-12-18

    The Feast-Famine (FF) process has been frequently used to select polyhydroxyalkanoate (PHA)-accumulating mixed cultures (MCs), but there has been little insight into the ecophysiology of the microbial community during the selection process. In three FF systems with well-defined conditions, synchronized variations in higher-order properties of MCs and complicate microbial community succession mainly including enrichment and elimination of non-top competitors and unexpected turnover of top competitors, were observed. Quantification of PHA-accumulating function genes (phaC) revealed that the top competitors maintained the PHA synthesis by playing consecutive roles when the highly dynamic turnover occurred. Due to its specific physiological characteristics during the PHA-accumulating process, Thauera strain OTU 7 was found to be responsible for the fluctuating SVI, which threatened the robustness of the FF system. This trait was also responsible for its later competitive exclusion by the other PHA-producer, Paracoccus strain OTU 1. Deterministic processes dominated the entire FF system, resulting in the inevitable microbial community succession in the acclimation phase and maintenance of the stable PHA-accumulating function in the maturation phase. However, neutral processes, likely caused by predation from bacterial phages, also occurred, which led to the unpredictable temporal dynamics of the top competitors. Copyright © 2017. Published by Elsevier Ltd.

  1. Characteristics of microbial community involved in early biofilms formation under the influence of wastewater treatment plant effluent.

    Science.gov (United States)

    Peng, Yuke; Li, Jie; Lu, Junling; Xiao, Lin; Yang, Liuyan

    2018-04-01

    Effluents from wastewater treatment plants (WWTPs) containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16S and 18S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be "biofilm-specific", with only a few dominant operational taxonomic units (OTUs) shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities. Copyright © 2017. Published by Elsevier B.V.

  2. Spatial variability in photosynthetic and heterotrophic activity drives localized δ13C org fluctuations and carbonate precipitation in hypersaline microbial mats.

    Science.gov (United States)

    Houghton, J; Fike, D; Druschel, G; Orphan, V; Hoehler, T M; Des Marais, D J

    2014-11-01

    Modern laminated photosynthetic microbial mats are ideal environments to study how microbial activity creates and modifies carbon and sulfur isotopic signatures prior to lithification. Laminated microbial mats from a hypersaline lagoon (Guerrero Negro, Baja California, Mexico) maintained in a flume in a greenhouse at NASA Ames Research Center were sampled for δ(13) C of organic material and carbonate to assess the impact of carbon fixation (e.g., photosynthesis) and decomposition (e.g., bacterial respiration) on δ(13) C signatures. In the photic zone, the δ(13) C org signature records a complex relationship between the activities of cyanobacteria under variable conditions of CO2 limitation with a significant contribution from green sulfur bacteria using the reductive TCA cycle for carbon fixation. Carbonate is present in some layers of the mat, associated with high concentrations of bacteriochlorophyll e (characteristic of green sulfur bacteria) and exhibits δ(13) C signatures similar to DIC in the overlying water column (-2.0‰), with small but variable decreases consistent with localized heterotrophic activity from sulfate-reducing bacteria (SRB). Model results indicate respiration rates in the upper 12 mm of the mat alter in situ pH and HCO3- concentrations to create both phototrophic CO2 limitation and carbonate supersaturation, leading to local precipitation of carbonate minerals. The measured activity of SRB with depth suggests they variably contribute to decomposition in the mat dependent on organic substrate concentrations. Millimeter-scale variability in the δ(13) C org signature beneath the photic zone in the mat is a result of shifting dominance between cyanobacteria and green sulfur bacteria with the aggregate signature overprinted by heterotrophic reworking by SRB and methanogens. These observations highlight the impact of sedimentary microbial processes on δ(13) C org signatures; these processes need to be considered when attempting to relate

  3. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  4. Dementia & Driving

    Science.gov (United States)

    ... have to give up driving. Many people associate driving with self-reliance and freedom; the loss of driving privileges ... familiar roads and avoid long distances. Avoid heavy traffic and heavily traveled roads. Avoid driving at night and in bad weather. Reduce the ...

  5. Mechanisms and rates of bacterial colonization of sinking aggregates

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Grossart, H.P.; Ploug, H.

    2002-01-01

    Quantifying the rate at which bacteria colonize aggregates is a key to understanding microbial turnover of aggregates. We used encounter models based on random walk and advection-diffusion considerations to predict colonization rates from the bacteria's motility patterns (swimming speed, tumbling...

  6. Colonic transit time is related to bacterial metabolism and mucosal turnover in the gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    2016-01-01

    Little is known about how colonic transit time relates to human colonic metabolism and its importance for host health, although a firm stool consistency, a proxy for a long colonic transit time, has recently been positively associated with gut microbial richness. Here, we show that colonic transi...... does not per se imply a healthy gut microbial ecosystem and points at colonic transit time as a highly important factor to consider in microbiome and metabolomics studies.......Little is known about how colonic transit time relates to human colonic metabolism and its importance for host health, although a firm stool consistency, a proxy for a long colonic transit time, has recently been positively associated with gut microbial richness. Here, we show that colonic transit...... time in humans, assessed using radio-opaque markers, is associated with overall gut microbial composition, diversity and metabolism. We find that a long colonic transit time associates with high microbial richness and is accompanied by a shift in colonic metabolism from carbohydrate fermentation...

  7. Anaerobic microbial dehalogenation

    NARCIS (Netherlands)

    Smidt, H.; Vos, de W.M.

    2004-01-01

    The natural production and anthropogenic release of halogenated hydrocarbons into the environment has been the likely driving force for the evolution of an unexpectedly high microbial capacity to dehalogenate different classes of xenobiotic haloorganics. This contribution provides an update on the

  8. Microbial composition of guava (Psidium guajava), hibiscus ...

    African Journals Online (AJOL)

    Microbial composition of guava (Psidium guajava), hibiscus (Hibiscus-rosa sinensis), mango (Mangifera indica) and pumpkin (Telfairia occidentalis Hook) ... African Journal of Biotechnology ... The microbial genera isolated from this study showed that, both human and plant pathogens can colonize plants' phyllosphere.

  9. Distracted driving

    Science.gov (United States)

    ... including maps) The Dangers of Talking on the Phone While Driving You are four times more likely to get ... of reach. If you are caught using a phone while driving, you may risk a ticket or fine. Most ...

  10. Distracted Driving

    Science.gov (United States)

    ... and increased awareness of distracted driving using radio advertisements, news stories, and similar media. After the projects ... available at www.trafficsafetymarketing.gov . Distracted Driving Enforcement – TV Ads (Paid). For re-tagging, go to: www. ...

  11. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  12. Diatom-driven recolonization of microbial mat-dominated siliciclastic tidal flat sediments.

    Science.gov (United States)

    Pan, Jerónimo; Cuadrado, Diana G; Bournod, Constanza N

    2017-10-01

    Modern microbial mats and biofilms play a paramount role in sediment biostabilization. When sporadic storms affect tidal flats of Bahía Blanca Estuary, the underlying siliciclastic sediment is exposed by physical disruption of the mat, and in a few weeks' lapse, a microbial community re-establishes. With the objective of studying colonization patterns and the ecological succession of microorganisms at the scale of these erosional structures, these were experimentally made and their biological recolonization followed for 8 weeks, with replication in winter and spring. Motile pennate diatoms led the initial colonization following two distinct patterns: a dominance by Cylindrotheca closterium in winter and by naviculoid and nitzschioid diatoms in spring. During the first 7 days, cell numbers increased 2- to 17-fold. Cell densities further increased exhibiting sigmoidal community growth, reaching 2.9-8.9 × 106 cells cm-3 maxima around day 30; centric diatoms maintained low densities throughout. In 56 days after removal of the original mat, filamentous cyanobacteria that dominate mature mats did not establish a significant biomass, leading to the rejection of the hypothesis that cyanobacteria would drive the colonization. The observed dominance of pennate diatoms is attributed to extrinsic factors determined by tidal flooding, and intrinsic ones, e.g. motility, nutrient affinity and high growth rate. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Bacterial Endophyte Colonization and Distribution within Plants

    Directory of Open Access Journals (Sweden)

    Shyam L. Kandel

    2017-11-01

    Full Text Available The plant endosphere contains a diverse group of microbial communities. There is general consensus that these microbial communities make significant contributions to plant health. Both recently adopted genomic approaches and classical microbiology techniques continue to develop the science of plant-microbe interactions. Endophytes are microbial symbionts residing within the plant for the majority of their life cycle without any detrimental impact to the host plant. The use of these natural symbionts offers an opportunity to maximize crop productivity while reducing the environmental impacts of agriculture. Endophytes promote plant growth through nitrogen fixation, phytohormone production, nutrient acquisition, and by conferring tolerance to abiotic and biotic stresses. Colonization by endophytes is crucial for providing these benefits to the host plant. Endophytic colonization refers to the entry, growth and multiplication of endophyte populations within the host plant. Lately, plant microbiome research has gained considerable attention but the mechanism allowing plants to recruit endophytes is largely unknown. This review summarizes currently available knowledge about endophytic colonization by bacteria in various plant species, and specifically discusses the colonization of maize plants by Populus endophytes.

  14. Clostridium difficile – From Colonization to Infection

    Science.gov (United States)

    Schäffler, Holger; Breitrück, Anne

    2018-01-01

    Clostridium difficile is the most frequent cause of nosocomial antibiotic-associated diarrhea. The incidence of C. difficile infection (CDI) has been rising worldwide with subsequent increases in morbidity, mortality, and health care costs. Asymptomatic colonization with C. difficile is common and a high prevalence has been found in specific cohorts, e.g., hospitalized patients, adults in nursing homes and in infants. However, the risk of infection with C. difficile differs significantly between these cohorts. While CDI is a clear indication for therapy, colonization with C. difficile is not believed to be a direct precursor for CDI and therefore does not require treatment. Antibiotic therapy causes alterations of the intestinal microbial composition, enabling C. difficile colonization and consecutive toxin production leading to disruption of the colonic epithelial cells. Clinical symptoms of CDI range from mild diarrhea to potentially life-threatening conditions like pseudomembranous colitis or toxic megacolon. While antibiotics are still the treatment of choice for CDI, new therapies have emerged in recent years such as antibodies against C. difficile toxin B and fecal microbial transfer (FMT). This specific therapy for CDI underscores the role of the indigenous bacterial composition in the prevention of the disease in healthy individuals and its role in the pathogenesis after alteration by antibiotic treatment. In addition to the pathogenesis of CDI, this review focuses on the colonization of C. difficile in the human gut and factors promoting CDI. PMID:29692762

  15. Pile Driving

    Science.gov (United States)

    1987-01-01

    Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

  16. Colonic lymphoid follicles associated with colonic neoplasms

    International Nuclear Information System (INIS)

    Glick, S.N.; Teplick, S.K.; Ross, W.M.

    1986-01-01

    The authors prospectively evaluated 62 patients over 40 years old in whom lymphoid follicles were demonstrated on double-contrast enema examinations. Eighteen patients (29%) had no current radiographic evidence of, or history of, colonic neoplasms. Forty-four patients (71%) had an associated neoplasm. Fourteen patients had associated colonic carcinoma, and ten patients had a history of a previously resected colon cancer. One patient had previously undergone resection for ''polyps.'' Twenty-two patients had an associated ''polyp.'' There were no clinical or radiographic features that could reliably distinguish the neoplastic from the nonneoplastic groups. However, lymphoid follicles in the left colon or diffusely involving the colon were more likely to be associated with a colonic neoplasm. Lymphoid follicles were almost always identified near a malignant lesion

  17. Exocellular electron transfer in anaerobic microbial communities

    NARCIS (Netherlands)

    Stams, A.J.M.; Bok, de F.A.M.; Plugge, C.M.; Eekert, van M.H.A.; Dolfing, J.; Schraa, G.

    2006-01-01

    Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory

  18. Antegrade Colonic Lavage in Acute Colonic Obstruction

    OpenAIRE

    Foster, Michael E.; Johnson, Colin D.

    1986-01-01

    Conventional management of acute left sided colonic obstruction employs some form of proximal colostomy. Intraoperative antegrade colonic irrigation relieves proximal faecal loading and may permit safer primary resection and anastomosis. The results of a pilot study are presented, and are shown to be favourable.

  19. Impaired Driving

    Science.gov (United States)

    ... Get the Facts What Works: Strategies to Increase Car Seat and Booster Seat ... narcotics. 3 That’s one percent of the 111 million self-reported episodes of alcohol-impaired driving among U.S. ...

  20. Management of Colonic Volvulus

    Science.gov (United States)

    Gingold, Daniel; Murrell, Zuri

    2012-01-01

    Colonic volvulus is a common cause of large bowel obstruction worldwide. It can affect all parts of the colon, but most commonly occurs in the sigmoid and cecal areas. This disease has been described for centuries, and was studied by Hippocrates himself. Currently, colonic volvulus is the third most common cause of large bowel obstruction worldwide, and is responsible for ∼15% of large bowel obstructions in the United States. This article will discuss the history of colonic volvulus, and the predisposing factors that lead to this disease. Moreover, the epidemiology and diagnosis of each type of colonic volvulus, along with the various treatment options will be reviewed. PMID:24294126

  1. Microbial activity on ligno cellulosic material

    International Nuclear Information System (INIS)

    Abdullah, N.; Wan, H.Y.; Jalaludin, S.

    1991-01-01

    Study of rumen bacteria and fungi colonizing rice straw was conducted in situ while the ability of rumen fungi to produce polysaccharides was investigated in vitro. In the microbial colonization study by electron microscopy, it was observed that rice straw fragments were heavily colonized by bacteria and fungi after 6 h of incubation in the rumen of cattle and buffaloes. Extensive degradation of cell walls was observed, particularly with rice fragments after 24 h of incubation. The fungal isolate from the rumen of cattle when in straw showed high activity of cellobiose, CMCase and FPase and to a lesser extent, xylanase and cellulase. (author)

  2. Driving things

    DEFF Research Database (Denmark)

    Nevile, Maurice Richard

    2015-01-01

    I explore how participants organise involvement with objects brought into the car, relative to the demands of driving and social activity. Objects in cars commonly include phones or other technologies, food, body care products, texts, clothing, bags and carry items, toys, and even animals...... 2004, Haddington et al. 2012). I focus here especially on how the practical and interactional work of locating, seeing, placing, handling, hearing, and relinquishing, is ordered and accomplished relative to the emerging and contingent demands of both driving and social participation......, such that involvement with objects is constituted as secondary to driving in a multiactivity setting (e.g. Haddington et al. 2014). We see how events with, for, of, and even by objects can occur as predictable, planned and even designed for (e.g. changing glasses, applying body lotion), or might be unexpected...

  3. Ecology of root colonizing Massilia (Oxalobacteraceae.

    Directory of Open Access Journals (Sweden)

    Maya Ofek

    Full Text Available BACKGROUND: Ecologically meaningful classification of bacterial populations is essential for understanding the structure and function of bacterial communities. As in soils, the ecological strategy of the majority of root-colonizing bacteria is mostly unknown. Among those are Massilia (Oxalobacteraceae, a major group of rhizosphere and root colonizing bacteria of many plant species. METHODOLOGY/PRINCIPAL FINDINGS: The ecology of Massilia was explored in cucumber root and seed, and compared to that of Agrobacterium population, using culture-independent tools, including DNA-based pyrosequencing, fluorescence in situ hybridization and quantitative real-time PCR. Seed- and root-colonizing Massilia were primarily affiliated with other members of the genus described in soil and rhizosphere. Massilia colonized and proliferated on the seed coat, radicle, roots, and also on hyphae of phytopathogenic Pythium aphanidermatum infecting seeds. High variation in Massilia abundance was found in relation to plant developmental stage, along with sensitivity to plant growth medium modification (amendment with organic matter and potential competitors. Massilia absolute abundance and relative abundance (dominance were positively related, and peaked (up to 85% at early stages of succession of the root microbiome. In comparison, variation in abundance of Agrobacterium was moderate and their dominance increased at later stages of succession. CONCLUSIONS: In accordance with contemporary models for microbial ecology classification, copiotrophic and competition-sensitive root colonization by Massilia is suggested. These bacteria exploit, in a transient way, a window of opportunity within the succession of communities within this niche.

  4. Ecology of root colonizing Massilia (Oxalobacteraceae).

    Science.gov (United States)

    Ofek, Maya; Hadar, Yitzhak; Minz, Dror

    2012-01-01

    Ecologically meaningful classification of bacterial populations is essential for understanding the structure and function of bacterial communities. As in soils, the ecological strategy of the majority of root-colonizing bacteria is mostly unknown. Among those are Massilia (Oxalobacteraceae), a major group of rhizosphere and root colonizing bacteria of many plant species. The ecology of Massilia was explored in cucumber root and seed, and compared to that of Agrobacterium population, using culture-independent tools, including DNA-based pyrosequencing, fluorescence in situ hybridization and quantitative real-time PCR. Seed- and root-colonizing Massilia were primarily affiliated with other members of the genus described in soil and rhizosphere. Massilia colonized and proliferated on the seed coat, radicle, roots, and also on hyphae of phytopathogenic Pythium aphanidermatum infecting seeds. High variation in Massilia abundance was found in relation to plant developmental stage, along with sensitivity to plant growth medium modification (amendment with organic matter) and potential competitors. Massilia absolute abundance and relative abundance (dominance) were positively related, and peaked (up to 85%) at early stages of succession of the root microbiome. In comparison, variation in abundance of Agrobacterium was moderate and their dominance increased at later stages of succession. In accordance with contemporary models for microbial ecology classification, copiotrophic and competition-sensitive root colonization by Massilia is suggested. These bacteria exploit, in a transient way, a window of opportunity within the succession of communities within this niche.

  5. Toward Understanding, Managing, and Protecting Microbial Ecosystems

    Science.gov (United States)

    Bodelier, Paul L. E.

    2011-01-01

    Microbial communities are at the very basis of life on earth, catalyzing biogeochemical reactions driving global nutrient cycles. However, unlike for plants and animals, microbial diversity is not on the biodiversity–conservation agenda. The latter, however, would imply that microbial diversity is not under any threat by anthropogenic disturbance or climate change. This maybe a misconception caused by the rudimentary knowledge we have concerning microbial diversity and its role in ecosystem functioning. This perspective paper identifies major areas with knowledge gaps within the field of environmental microbiology that preclude a comprehension of microbial ecosystems on the level we have for plants and animals. Opportunities and challenges are pointed out to open the microbial black box and to go from descriptive to predictive microbial ecology. PMID:21747797

  6. Towards understanding, managing and protecting microbial ecosystems

    Directory of Open Access Journals (Sweden)

    Paul eBodelier

    2011-04-01

    Full Text Available Microbial communities are at the very basis of life on earth, catalysing biogeochemical reactions driving global nutrient cycles. However, unlike for plants and animals, microbial diversity is not on the biodiversity conservation agenda. The latter, however, would imply that microbial diversity is not under any threat by anthropogenic disturbance or climate change. This maybe a misconception caused by the rudimentary knowledge we have concerning microbial diversity and its role in ecosystem functioning. This perspective paper indentifies major areas with knowledge gaps within the field of environmental microbiology that preclude a comprehension of microbial ecosystems on the level we have for plants and animals. Opportunities and challenges are pointed out to open the microbial black box and to go from descriptive to predictive microbial ecology.

  7. Toward understanding, managing, and protecting microbial ecosystems.

    Science.gov (United States)

    Bodelier, Paul L E

    2011-01-01

    Microbial communities are at the very basis of life on earth, catalyzing biogeochemical reactions driving global nutrient cycles. However, unlike for plants and animals, microbial diversity is not on the biodiversity-conservation agenda. The latter, however, would imply that microbial diversity is not under any threat by anthropogenic disturbance or climate change. This maybe a misconception caused by the rudimentary knowledge we have concerning microbial diversity and its role in ecosystem functioning. This perspective paper identifies major areas with knowledge gaps within the field of environmental microbiology that preclude a comprehension of microbial ecosystems on the level we have for plants and animals. Opportunities and challenges are pointed out to open the microbial black box and to go from descriptive to predictive microbial ecology.

  8. Colonic transit time relates to bacterial metabolism and mucosal turnover in the human gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    catabolism as reflected by microbial metabolites in urine. This results in a number of potentially deleterious protein-derived metabolites. Additionally, longer colonic transit time correlates with metabolites likely reflecting reduced renewal of the colonic mucosa. Together, this suggests that a high gut...

  9. Dietary factors and the occurence of truncating APC mutations in sporadic colon carcinomas: a Dutch population-based study

    NARCIS (Netherlands)

    Diergaarde, B.; Geloof, van W.L.; Muijen, van G.N.P.; Kok, F.J.; Kampman, E.

    2003-01-01

    The interactions between environmental factors and the genetic and epigenetic changes that drive colon carcinogenesis are not clear. Dietary factors reported previously to be associated with colon cancer risk may well influence the occurrence of specific somatic alterations in colon tumors. To

  10. Dietary factors and the occurrence of truncating APC mutations in sporadic colon carcinomas: a Dutch population-based study.

    NARCIS (Netherlands)

    Diergaarde, B.; Geloof, W. van; Muijen, G.N.P. van; Kok, F.J.; Kampman, E.

    2003-01-01

    The interactions between environmental factors and the genetic and epigenetic changes that drive colon carcinogenesis are not clear. Dietary factors reported previously to be associated with colon cancer risk may well influence the occurrence of specific somatic alterations in colon tumors. To

  11. CT in colon cancer

    International Nuclear Information System (INIS)

    Fujita, Nobuyuki; Hasegawa, Takashi; Kubo, Kozo; Ogawa, Hajime; Sato, Yukihiko; Tomita, Masayoshi; Hanawa, Makoto; Matsuzawa, Tohru; Nishioka, Ken

    1990-01-01

    CT pictures from 59 lesions of advanced colon cancer including rectal cancer were reviewed to evaluate a role of CT in preoperative staging diagnosis. CT findings were recorded following general rules for clinical and pathological studies on cancer of colon rectum and anus, proposed by Japanese society for cancer of colon and rectum. Tumors were detected in 90% of advanced colon cancers. Sensitivity in local extension (S factor) was 58.0%. Sensitivity in lymphonode involvement (N factor) was 50.0%. Sensitivity in final staging diagnosis, dividing colon cancer into two groups below st II and above st III, was 63.3%. Further study should be necessitated to provide useful information for preoperative staging diagnosis of colon cancer. (author)

  12. Community Drive

    DEFF Research Database (Denmark)

    Magnussen, Rikke

    2018-01-01

    Schools and educational institutions are challenged by not adequately educating students for independent knowledge collaboration and solving of complex societal challenges (Bundsgaard & Hansen, 2016; Slot et al., 2017). As an alternative strategy to formal learning has Community-driven research...... opportunity to break boundaries between research institutions and surrounding communities through the involvement of new types of actors, knowledge forms and institutions (OECD, 2011). This paper presents the project Community Drive a three year cross disciplinary community-driven game– and data-based project....... In the paper we present how the project Community Drive initiated in May 2018 is based on results from pilot projects conducted from 2014 – 2017. Overall these studies showed that it is a strong motivational factor for students to be given the task to change their living conditions through redesign...

  13. An Act of Colonization

    DEFF Research Database (Denmark)

    Rasmussen, Anders Bo

    When Gideon Welles, U.S. Secretary of the Navy, sat down to write his diary entry on September 26, 1862, his thoughts turned once more to colonization. President Lincoln was an ardent proponent of colonization, “the government-promoted settlement of black Americans in Africa or some other location....... Croix. Thus, when the Lincoln administration seriously considered colonization plans in 1862, Danish Charge d’Affaires Waldemar Raasløff offered free transport for freedmen to the Caribbean island, where there was a “distinct lack of laborers.” As a small first step towards colonization, Denmark...

  14. Colon cancer screening

    Science.gov (United States)

    Screening for colon cancer; Colonoscopy - screening; Sigmoidoscopy - screening; Virtual colonoscopy - screening; Fecal immunochemical test; Stool DNA test; sDNA test; Colorectal cancer - screening; Rectal ...

  15. Colonization of torrefied grass fibers by plant-beneficial microorganisms

    NARCIS (Netherlands)

    Trifonova, R.; Babini, V.; Postma, J.; Ketelaars, J.J.M.H.; van Elsas, J.D.

    This study aimed to assess the colonization of thermally treated (i.e. torrefied) grass fibers (TGFs), a new prospective ingredient of potting soil. Eleven bacterial strains and one fungus, Coniochaeta ligniaria F/TGF15, all isolated from TGF or its extract after inoculation with a soil microbial

  16. Colonization of torrefied grass fibers by plant beneficial microorganisms

    NARCIS (Netherlands)

    Trifonova, R.D.; Babini, V.; Postma, J.; Ketelaars, J.J.M.H.; Elsas, van J.D.

    2009-01-01

    This study aimed to assess the colonization of thermally treated (i.e. torrefied) grass fibers (TGFs), a new prospective ingredient of potting soil. Eleven bacterial strains and one fungus, Coniochaeta ligniaria F/TGF15, all isolated from TGF or its extract after inoculation with a soil microbial

  17. Diet, genes, and microbes: complexities of colon cancer prevention.

    Science.gov (United States)

    Birt, Diane F; Phillips, Gregory J

    2014-01-01

    Colorectal cancer is one of the leading causes of cancer-related deaths in the United States, and generally, as countries climb the economic ladder, their rates of colon cancer increase. Colon cancer was an early disease where key genetic mutations were identified as important in disease progression, and there is considerable interest in determining whether specific mutations sensitize the colon to cancer prevention strategies. Epidemiological studies have revealed that fiber- and vegetable-rich diets and physical activity are associated with reduced rates of colon cancer, while consumption of red and processed meat, or alcoholic beverages, and overconsumption as reflected in obesity are associated with increased rates. Animal studies have probed these effects and suggested directions for further refinement of diet in colon cancer prevention. Recently a central role for the microorganisms in the gastrointestinal tract in colon cancer development is being probed, and it is hypothesized that the microbes may integrate diet and host genetics in the etiology of the disease. This review provides background on dietary, genetic, and microbial impacts on colon cancer and describes an ongoing project using rodent models to assess the ability of digestion-resistant starch in the integration of these factors with the goal of furthering colon cancer prevention.

  18. CT Findings of Colonic Complications Associated with Colon Cancer

    International Nuclear Information System (INIS)

    Kim, Sang Won; Shin, Hyeong Cheol; Kim, Il Young; Kim, Young Tong; Kim, Chang Jin

    2010-01-01

    A broad spectrum of colonic complications can occur in patients with colon cancer. Clinically, some of these complications can obscure the presence of underlying malignancies in the colon and these complications may require emergency surgical management. The complications of the colon that can be associated with colon cancer include obstruction, perforation, abscess formation, acute appendicitis, ischemic colitis and intussusception. Although the majority of these complications only rarely occur, familiarity with the various manifestations of colon cancer complications will facilitate making an accurate diagnosis and administering prompt management in these situations. The purpose of this pictorial essay is to review the CT appearance of the colonic complications associated with colon cancer

  19. CT Findings of Colonic Complications Associated with Colon Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Won; Shin, Hyeong Cheol; Kim, Il Young; Kim, Young Tong; Kim, Chang Jin [Cheonan Hospital, Soonchunhyang University, Cheonan (Korea, Republic of)

    2010-04-15

    A broad spectrum of colonic complications can occur in patients with colon cancer. Clinically, some of these complications can obscure the presence of underlying malignancies in the colon and these complications may require emergency surgical management. The complications of the colon that can be associated with colon cancer include obstruction, perforation, abscess formation, acute appendicitis, ischemic colitis and intussusception. Although the majority of these complications only rarely occur, familiarity with the various manifestations of colon cancer complications will facilitate making an accurate diagnosis and administering prompt management in these situations. The purpose of this pictorial essay is to review the CT appearance of the colonic complications associated with colon cancer.

  20. Colon and rectal cancer

    International Nuclear Information System (INIS)

    Saldombide, L.; Cordoba, A.

    2010-01-01

    This study is about the diagnosis, therapy and monitoring of colon cancer. The techniques used are the endoscopy with biopsy in the pre and post operative colon surgery, abdominal ultrasound, chest X-ray studies of hemogram as well as liver and renal function

  1. Colon of the rat

    International Nuclear Information System (INIS)

    Lindstroem, C.G.; Rosengren, J.-E.; Fork, F.-T.

    1979-01-01

    The anatomy and radiologic appearance of the colon in rats are described on the basis of 300 animals treated with carcinogenic agents and 40 normal rats. The macroscopic and microscopic appearance of the mucosa varies in the different parts of the colon. Lymphoid plaques are normal structures. The results justify a new anatomic nomenclature. (Auth.)

  2. Shotgun microbial profiling of fossil remains

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Ermini, Luca; Jónsson, Hákon

    2014-01-01

    the specimen of interest, but instead reflect environmental organisms that colonized the specimen after death. Here, we characterize the microbial diversity recovered from seven c. 200- to 13 000-year-old horse bones collected from northern Siberia. We use a robust, taxonomy-based assignment approach...... to identify the microorganisms present in ancient DNA extracts and quantify their relative abundance. Our results suggest that molecular preservation niches exist within ancient samples that can potentially be used to characterize the environments from which the remains are recovered. In addition, microbial...... community profiling of the seven specimens revealed site-specific environmental signatures. These microbial communities appear to comprise mainly organisms that colonized the fossils recently. Our approach significantly extends the amount of useful data that can be recovered from ancient specimens using...

  3. Electric drives

    Energy Technology Data Exchange (ETDEWEB)

    1986-10-01

    Several electric vehicles have been tested in long-term tests, i.e. an electric passenger car (maximum speed 115 km/h) and several busses for use in pedestrians' zones, spas, airports, natural reserves, and urban transportation (DUO busses). The ICE high-speed train is discussed in some detail, i.e. its aeroacoustic and aerodynamic design, running gear, computer-controlled drives and brakes, diagnostic systems, and electrical equipment. The Berlin Maglev system is mentioned as well as current inverters in rail vehicles. (HWJ).

  4. Microbial biosensors

    International Nuclear Information System (INIS)

    Le Yu; Chen, Wilfred; Mulchandani, Ashok

    2006-01-01

    A microbial biosensor is an analytical device that couples microorganisms with a transducer to enable rapid, accurate and sensitive detection of target analytes in fields as diverse as medicine, environmental monitoring, defense, food processing and safety. The earlier microbial biosensors used the respiratory and metabolic functions of the microorganisms to detect a substance that is either a substrate or an inhibitor of these processes. Recently, genetically engineered microorganisms based on fusing of the lux, gfp or lacZ gene reporters to an inducible gene promoter have been widely applied to assay toxicity and bioavailability. This paper reviews the recent trends in the development and application of microbial biosensors. Current advances and prospective future direction in developing microbial biosensor have also been discussed

  5. Safe driving for teens

    Science.gov (United States)

    Driving and teenagers; Teens and safe driving; Automobile safety - teenage drivers ... months before taking friends as passengers. Teenage-related driving deaths occur more often in certain conditions. OTHER SAFETY TIPS FOR TEENS Reckless driving is still a ...

  6. The Role of Curcumin in Modulating Colonic Microbiota During Colitis and Colon Cancer Prevention

    Science.gov (United States)

    McFadden, Rita-Marie T.; Larmonier, Claire B.; Shehab, Kareem W.; Midura-Kiela, Monica; Ramalingam, Rajalakshmy; Harrison, Christy A.; Besselsen, David G.; Chase, John H.; Caporaso, J. Gregory; Jobin, Christian; Ghishan, Fayez K.; Kiela, Pawel R.

    2015-01-01

    Background Intestinal microbiota influences the progression of colitis-associated colorectal cancer (CAC). With diet being a key determinant of the gut microbial ecology, dietary interventions are an attractive avenue for the prevention of CAC. Curcumin is the most active constituent of the ground rhizome of the Curcuma Longa plant, which has been demonstrated to have anti-inflammatory, anti-oxidative and anti-proliferative properties. Methods Il10−/− mice on 129/SvEv background were used as a model of CAC. Starting at 10 weeks of age, WT or Il10−/− mice received six weekly i.p. injections of azoxymethane (AOM) or saline, and were started on either a control or curcumin-supplemented diet. Stools were collected every 4 weeks for microbial community analysis. Mice were sacrificed at 30 weeks of age. Results Curcumin-supplemented diet increased survival, decreased colon weight/length ratio, and at 0.5%, entirely eliminated tumor burden. Although colonic histology indicated improvement with curcumin, no effects of mucosal immune responses have been observed in PBS/Il10−/− mice, and limited effects were seen in AOM/Il10−/− mice. In WT and in Il10−/− mice, curcumin increased bacterial richness, prevented age-related decrease in alpha diversity, increased the relative abundance of Lactobacillales, and decreased Coriobacterales order. Taxonomic profile of AOM/Il10−/− mice receiving curcumin was more similar to those of wild-type mice than those fed control diet. Conclusions In AOM/Il10−/− model, curcumin reduced or eliminated colonic tumor burden with limited effects on mucosal immune responses. The beneficial effect of curcumin on tumorigenesis was associated with the maintenance of a more diverse colonic microbial ecology. PMID:26218141

  7. Microbial community functional change during vertebrate carrion decomposition.

    Directory of Open Access Journals (Sweden)

    Jennifer L Pechal

    Full Text Available Microorganisms play a critical role in the decomposition of organic matter, which contributes to energy and nutrient transformation in every ecosystem. Yet, little is known about the functional activity of epinecrotic microbial communities associated with carrion. The objective of this study was to provide a description of the carrion associated microbial community functional activity using differential carbon source use throughout decomposition over seasons, between years and when microbial communities were isolated from eukaryotic colonizers (e.g., necrophagous insects. Additionally, microbial communities were identified at the phyletic level using high throughput sequencing during a single study. We hypothesized that carrion microbial community functional profiles would change over the duration of decomposition, and that this change would depend on season, year and presence of necrophagous insect colonization. Biolog EcoPlates™ were used to measure the variation in epinecrotic microbial community function by the differential use of 29 carbon sources throughout vertebrate carrion decomposition. Pyrosequencing was used to describe the bacterial community composition in one experiment to identify key phyla associated with community functional changes. Overall, microbial functional activity increased throughout decomposition in spring, summer and winter while it decreased in autumn. Additionally, microbial functional activity was higher in 2011 when necrophagous arthropod colonizer effects were tested. There were inconsistent trends in the microbial function of communities isolated from remains colonized by necrophagous insects between 2010 and 2011, suggesting a greater need for a mechanistic understanding of the process. These data indicate that functional analyses can be implemented in carrion studies and will be important in understanding the influence of microbial communities on an essential ecosystem process, carrion decomposition.

  8. A Case of Sigmoid Colon Tuberculosis Mimicking Colon Cancer

    OpenAIRE

    Yu, Seong-Min; Park, Jong-Hwan; Kim, Min-Dae; Lee, Hee-Ryong; Jung, Peel; Ryu, Tae-Hyun; Choi, Seung-Ho; Lee, Il-Seon

    2012-01-01

    Tuberculosis of the sigmoid colon is a rare disorder. An 80-year-old man visited Bongseng Memorial Hospital for medical examination. A colonoscopy was performed, and a lesion in the sigmoid colon that was suspected to be colon cancer was found. A biopsy was performed, and tuberculous enteritis with chronic granulomatous inflammation was diagnosed. Intestinal tuberculosis is most frequent in the ileocecal area, followed by the ascending colon, transverse colon, duodenum, stomach, and sigmoid c...

  9. Microbial Regulation in Gorgonian Corals

    Directory of Open Access Journals (Sweden)

    Laura D. Mydlarz

    2012-06-01

    Full Text Available Gorgonian corals possess many novel natural products that could potentially mediate coral-bacterial interactions. Since many bacteria use quorum sensing (QS signals to facilitate colonization of host organisms, regulation of prokaryotic cell-to-cell communication may represent an important bacterial control mechanism. In the present study, we examined extracts of twelve species of Caribbean gorgonian corals, for mechanisms that regulate microbial colonization, such as antibacterial activity and QS regulatory activity. Ethanol extracts of gorgonians collected from Puerto Rico and the Florida Keys showed a range of both antibacterial and QS activities using a specific Pseudomonas aeruginosa QS reporter, sensitive to long chain AHLs and a short chain N-acylhomoserine lactones (AHL biosensor, Chromobacterium violaceium. Overall, the gorgonian corals had higher antimicrobial activity against non-marine strains when compared to marine strains. Pseudopterogorgia americana, Pseusopterogorgia acerosa, and Pseudoplexuara flexuosa had the highest QS inhibitory effect. Interestingly, Pseudoplexuara porosa extracts stimulated QS activity with a striking 17-fold increase in signal. The stimulation of QS by P. porosa or other elements of the holobiont may encourage colonization or recruitment of specific microbial species. Overall, these results suggest the presence of novel stimulatory QS, inhibitory QS and bactericidal compounds in gorgonian corals. A better understanding of these compounds may reveal insight into coral-microbial ecology and whether a therapeutic potential exists.

  10. Selling space colonization and immortality: A psychosocial, anthropological critique of the rush to colonize Mars

    Science.gov (United States)

    Slobodian, Rayna Elizabeth

    2015-08-01

    Extensive media coverage regarding the proposal to send four people to Mars by 2025 has exploded recently. Private enterprise has taken the reins to venture into space, which has typically only been reserved for government agencies. I argue, that with this new direction comes less regulation, raising questions regarding the ethics of sending people into outer space to colonize Mars within a decade. Marketers selling colonization to the public include perspectives such as biological drives, species survival, inclusiveness and utopian ideals. I challenge these narratives by suggesting that much of our desire to colonize space within the next decade is motivated by ego, money and romanticism. More specifically, I will examine the roles that fear and stories of immortality play within selling space and how those stories are marketed. I am passionate about space and hope that one day humanity will colonize other worlds, but the rush to settle is dangerous and careless. I assert that humanity should first gain more experience and knowledge before colonizing outer space, using this research to mitigate the risk to astronauts and proceed with careful consideration for the lives of potential astronauts.

  11. Carotenoids and colon cancer.

    Science.gov (United States)

    Slattery, M L; Benson, J; Curtin, K; Ma, K N; Schaeffer, D; Potter, J D

    2000-02-01

    Carotenoids have numerous biological properties that may underpin a role for them as chemopreventive agents. However, except for beta-carotene, little is known about how dietary carotenoids are associated with common cancers, including colon cancer. The objective of this study was to evaluate associations between dietary alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, and beta-cryptoxanthin and the risk of colon cancer. Data were collected from 1993 case subjects with first primary incident adenocarcinoma of the colon and from 2410 population-based control subjects. Dietary data were collected from a detailed diet-history questionnaire and nutrient values for dietary carotenoids were obtained from the US Department of Agriculture-Nutrition Coordinating Center carotenoid database (1998 updated version). Lutein was inversely associated with colon cancer in both men and women [odds ratio (OR) for upper quintile of intake relative to lowest quintile of intake: 0.83; 95% CI: 0.66, 1.04; P = 0.04 for linear trend]. The greatest inverse association was observed among subjects in whom colon cancer was diagnosed when they were young (OR: 0.66; 95% CI: 0.48, 0.92; P = 0.02 for linear trend) and among those with tumors located in the proximal segment of the colon (OR: 0.65; 95% CI: 0.51, 0.91; P lettuce, tomatoes, oranges and orange juice, carrots, celery, and greens. These data suggest that incorporating these foods into the diet may help reduce the risk of developing colon cancer.

  12. Microbial desalination cells for energy production and desalination

    KAUST Repository

    Kim, Younggy; Logan, Bruce E.

    2013-01-01

    Microbial desalination cells (MDCs) are a new, energy-sustainable method for using organic matter in wastewater as the energy source for desalination. The electric potential gradient created by exoelectrogenic bacteria desalinates water by driving

  13. Microbial glycoproteomics

    DEFF Research Database (Denmark)

    Halim, Adnan; Anonsen, Jan Haug

    2017-01-01

    Mass spectrometry-based "-omics" technologies are important tools for global and detailed mapping of post-translational modifications. Protein glycosylation is an abundant and important post translational modification widespread throughout all domains of life. Characterization of glycoproteins...... and research in this area is rapidly accelerating. Here, we review recent developments in glycoproteomic technologies with a special focus on microbial protein glycosylation....

  14. Patterns of gut bacterial colonization in three primate species.

    Directory of Open Access Journals (Sweden)

    Erin A McKenney

    Full Text Available Host fitness is impacted by trillions of bacteria in the gastrointestinal tract that facilitate development and are inextricably tied to life history. During development, microbial colonization primes the gut metabolism and physiology, thereby setting the stage for adult nutrition and health. However, the ecological rules governing microbial succession are poorly understood. In this study, we examined the relationship between host lineage, captive diet, and life stage and gut microbiota characteristics in three primate species (infraorder, Lemuriformes. Fecal samples were collected from captive lemur mothers and their infants, from birth to weaning. Microbial DNA was extracted and the v4 region of 16S rDNA was sequenced on the Illumina platform using protocols from the Earth Microbiome Project. Here, we show that colonization proceeds along different successional trajectories in developing infants from species with differing dietary regimes and ecological profiles: frugivorous (fruit-eating Varecia variegata, generalist Lemur catta, and folivorous (leaf-eating Propithecus coquereli. Our analyses reveal community membership and succession patterns consistent with previous studies of human infants, suggesting that lemurs may serve as a useful model of microbial ecology in the primate gut. Each lemur species exhibits distinct species-specific bacterial diversity signatures correlating to life stages and life history traits, implying that gut microbial community assembly primes developing infants at species-specific rates for their respective adult feeding strategies.

  15. CT findings of colonic diverticulitis

    International Nuclear Information System (INIS)

    Sasaki, Shigeru; Ohba, Satoru; Mizutani, Masaru

    1998-01-01

    Although colonic diverticulitis has no indication for operation, but in some mistaken cases were operated with a diagnosis of acute appendicitis. We evaluated the CT findings of colonic diverticulitis about 19 cases and of asymptomatic colonic diverticula about 15 cases retrospectively. Diagnosis was confirmed of barium enema and operation. CT are complementary methods of examination that can delineated the range of thickening of the colon and the extension of inflammatory changes around the colon. We also believe that CT findings of colonic diverticulitis are useful for differentiating from a diagnosis of appendicitis. (author)

  16. Temporal and spatial interplay of microbiota and intestinal mucosa drive establishment of immune homeostasis in conventionalized mice

    NARCIS (Netherlands)

    Aidy, El S.; Baarlen, van P.; Derrien, M.; Lindenbergh-Kortleve, D.J.; Hooiveld, G.J.; Levenez, F.; Dore, J.; Dekker, J.; Samsom, J.N.; Nieuwenhuis, E.E.S.; Kleerebezem, M.

    2012-01-01

    During colonization of germfree mice with the total fecal microbial community of their conventionally born and raised siblings (conventionalization), the intestinal mucosal immune system initiates and maintains a balanced immune response. However, the genetic regulation of these balanced,

  17. Complicated colonic intussusception

    Directory of Open Access Journals (Sweden)

    Justin James

    2012-01-01

    Full Text Available The manuscript deals with the case of a 53-year-old woman who developed large bowel obstruction. Per-rectal examination revealed a pedunculated lesion in the rectum; rigid sigmoidoscopy revealed a prolapsing pedunculated mass with a necrotic surface. The patient recovered well following anterior resection. Histology confirmed a pedunculated sub mucosal lipoma as the lead point for intussusception. Colonic intussusception is a rare cause of adult large bowel obstruction, and the preoperative clinical diagnosis of this condition can be difficult. Resection of the involved segment of the colon is the most appropriate choice of treatment in most such cases.

  18. Colonic potassium handling

    DEFF Research Database (Denmark)

    Sørensen, Mads Vaarby; Matos, Joana E.; Prætorius, Helle

    2010-01-01

    , intestinal K+ losses caused by activated ion secretion may become life threatening. This topical review provides an update of the molecular mechanisms and the regulation of mammalian colonic K+ absorption and secretion. It is motivated by recent results, which have identified the K+ secretory ion channel...... regulated by hormones and adapts readily to changes in dietary K+ intake, aldosterone and multiple local paracrine agonists. In chronic renal insufficiency, colonic K+ secretion is greatly enhanced and becomes an important accessory K+ excretory pathway. During severe diarrheal diseases of different causes...

  19. Submersible microbial fuel cell sensor for monitoring microbial activity and BOD in groundwater: Focusing on impact of anodic biofilm on sensor applicability

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2011-01-01

    was required for application of the sensor for microbial activity measurement, while biofilm‐colonized anode was needed for utilizing the sensor for BOD content measurement. The current density of SUMFC sensor equipped with a biofilm‐colonized anode showed linear relationship with BOD content, to up to 250 mg......A sensor, based on a submersible microbial fuel cell (SUMFC), was developed for in situ monitoring of microbial activity and biochemical oxygen demand (BOD) in groundwater. Presence or absence of a biofilm on the anode was a decisive factor for the applicability of the sensor. Fresh anode...

  20. Microbial xanthophylls.

    Science.gov (United States)

    Bhosale, Prakash; Bernstein, Paul S

    2005-09-01

    Xanthophylls are oxygenated carotenoids abundant in the human food supply. Lutein, zeaxanthin, and cryptoxanthin are major xanthophyll carotenoids in human plasma. The consumption of these xanthophylls is directly associated with reduction in the risk of cancers, cardiovascular disease, age-related macular degeneration, and cataract formation. Canthaxanthin and astaxanthin also have considerable importance in aquaculture for salmonid and crustacean pigmentation, and are of commercial interest for the pharmaceutical and food industries. Chemical synthesis is a major source for the heavy demand of xanthophylls in the consumer market; however, microbial producers also have potential as commercial sources. In this review, we discuss the biosynthesis, commercial utility, and major microbial sources of xanthophylls. We also present a critical review of current research and technologies involved in promoting microbes as potential commercial sources for mass production.

  1. Colonization, mouse-style

    Directory of Open Access Journals (Sweden)

    Searle Jeremy B

    2010-10-01

    Full Text Available Abstract Several recent papers, including one in BMC Evolutionary Biology, examine the colonization history of house mice. As well as background for the analysis of mouse adaptation, such studies offer a perspective on the history of movements of the humans that accidentally transported the mice. See research article: http://www.biomedcentral.com/1471-2148/10/325

  2. Zebrafish Axenic Larvae Colonization with Human Intestinal Microbiota.

    Science.gov (United States)

    Arias-Jayo, Nerea; Alonso-Saez, Laura; Ramirez-Garcia, Andoni; Pardo, Miguel A

    2018-04-01

    The human intestine hosts a vast and complex microbial community that is vital for maintaining several functions related with host health. The processes that determine the gut microbiome composition are poorly understood, being the interaction between species, the external environment, and the relationship with the host the most feasible. Animal models offer the opportunity to understand the interactions between the host and the microbiota. There are different gnotobiotic mice or rat models colonized with the human microbiota, however, to our knowledge, there are no reports on the colonization of germ-free zebrafish with a complex human intestinal microbiota. In the present study, we have successfully colonized 5 days postfertilization germ-free zebrafish larvae with the human intestinal microbiota previously extracted from a donor and analyzed by high-throughput sequencing the composition of the transferred microbial communities that established inside the zebrafish gut. Thus, we describe for first time which human bacteria phylotypes are able to colonize the zebrafish digestive tract. Species with relevant interest because of their linkage to dysbiosis in different human diseases, such as Akkermansia muciniphila, Eubacterium rectale, Faecalibacterium prausnitzii, Prevotella spp., or Roseburia spp. have been successfully transferred inside the zebrafish digestive tract.

  3. Schwannoma of the Colon

    Directory of Open Access Journals (Sweden)

    Ronaldo Nonose

    2009-09-01

    Full Text Available Schwannomas are neoplasms originating from Schwann cells, which are the cells forming nerve sheaths. These neoplasms generally involve peripheral nerves. They rarely affect the gastrointestinal tract and primary colon involvement is extremely rare. The objective of the present paper was to present a case of primary schwannoma of the sigmoid colon, unassociated with von Recklinghausen disease, that was histopathologically confirmed by means of an immunohistochemical panel. The patient was a 71-year-old woman who had had rectal bleeding when evacuating, with pain and tenesmus, for 4 months. She underwent colonoscopy, which identified a raised submucous lesion of 2.8 cm in diameter, located in the sigmoid colon, 30 cm from the anal margin. During examination, loop polypectomy with lesion excision was performed. Histopathological evaluation showed that this was a tumor of stromal origin. Its resection margins were compromised by neoplasia, and colon resection by means of videolaparoscopy was indicated. Conventional histopathological examination using the hematoxylin-eosin technique suggested that the neoplasm was of mesenchymal origin. An immunohistochemical panel was run for etiological confirmation, using anti-CD34 antibodies, desmin, cytokeratins (AE1/AE3, cKit, chromogranin and S-100 protein. The panel showed intense immunoexpression of S-100 protein. Investigation of the proliferative activity rate using Ki-67 antibodies showed that there was a low rate of mitotic activity, thus confirming the diagnosis of primary benign schwannoma of the colon. The patient’s postoperative evolution was uneventful and she remains in good health, without signs of tumor recurrence, 15 months after surgical excision.

  4. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  5. Extended driving impairs nocturnal driving performances.

    Directory of Open Access Journals (Sweden)

    Patricia Sagaspe

    Full Text Available Though fatigue and sleepiness at the wheel are well-known risk factors for traffic accidents, many drivers combine extended driving and sleep deprivation. Fatigue-related accidents occur mainly at night but there is no experimental data available to determine if the duration of prior driving affects driving performance at night. Participants drove in 3 nocturnal driving sessions (3-5 am, 1-5 am and 9 pm-5 am on open highway. Fourteen young healthy men (mean age [+/-SD] = 23.4 [+/-1.7] years participated Inappropriate line crossings (ILC in the last hour of driving of each session, sleep variables, self-perceived fatigue and sleepiness were measured. Compared to the short (3-5 am driving session, the incidence rate ratio of inappropriate line crossings increased by 2.6 (95% CI, 1.1 to 6.0; P<.05 for the intermediate (1-5 am driving session and by 4.0 (CI, 1.7 to 9.4; P<.001 for the long (9 pm-5 am driving session. Compared to the reference session (9-10 pm, the incidence rate ratio of inappropriate line crossings were 6.0 (95% CI, 2.3 to 15.5; P<.001, 15.4 (CI, 4.6 to 51.5; P<.001 and 24.3 (CI, 7.4 to 79.5; P<.001, respectively, for the three different durations of driving. Self-rated fatigue and sleepiness scores were both positively correlated to driving impairment in the intermediate and long duration sessions (P<.05 and increased significantly during the nocturnal driving sessions compared to the reference session (P<.01. At night, extended driving impairs driving performances and therefore should be limited.

  6. Patterns of early gut colonization shape future immune responses of the host

    DEFF Research Database (Denmark)

    Hansen, Camilla Hartmann Friis; Nielsen, Dennis Sandris; Kverka, Miloslav

    2012-01-01

    The most important trigger for immune system development is the exposure to microbial components immediately after birth. Moreover, targeted manipulation of the microbiota can be used to change host susceptibility to immune-mediated diseases. Our aim was to analyze how differences in early gut...... production. In conclusion, a time window exists that enables the artificial colonization of GF mice by a single oral dose of caecal content, which may modify the future immune phenotype of the host. Moreover, delayed microbial colonization of the gut causes permanent changes in the immune system....

  7. Microbial effects

    International Nuclear Information System (INIS)

    Sharpe, V.J.

    1985-10-01

    The long term safety and integrity of radioactive waste disposal sites proposed for use by Ontario Hydro may be affected by the release of radioactive gases. Microbes mediate the primary pathways of waste degradation and hence an assessment of their potential to produce gaseous end products from the breakdown of low level waste was performed. Due to a number of unknown variables, assumptions were made regarding environmental and waste conditions that controlled microbial activity; however, it was concluded that 14 C and 3 H would be produced, albeit over a long time scale of about 1500 years for 14 C in the worst case situation

  8. HARMONIC DRIVE SELECTION

    Directory of Open Access Journals (Sweden)

    Piotr FOLĘGA

    2014-03-01

    Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

  9. Microbial changes during pregnancy, birth and infancy

    Directory of Open Access Journals (Sweden)

    Meital Nuriel-Ohayon

    2016-07-01

    Full Text Available Several healthy developmental processes such as pregnancy, fetal development and infant development include a multitude of physiological changes: weight gain, hormonal and metabolic changes, as well as immune changes. In this review we present an additional important factor which both influences and is affected by these physiological processes- the microbiome. We summarize the known changes in microbiota composition at a variety of body sites including gut, vagina, oral cavity and placenta, throughout pregnancy, fetal development and early childhood. There is still a lot to be discovered; yet several pieces of research point to the healthy desired microbial changes. Future research is likely to unravel precise roles and mechanisms of the microbiota in gestation; perhaps linking the metabolic, hormonal and immune changes together. Although some research has started to link microbial dysbiosis and specific microbial populations with unhealthy pregnancy complications, it is important to first understand the context of the natural healthy microbial changes occurring. Until recently the placenta and developing fetus were considered to be germ free, containing no apparent microbiome. We present multiple study results showing distinct microbiota compositions in the placenta and meconium, alluding to early microbial colonization. These results may change dogmas and our overall understanding of the importance and roles of microbiota from the beginning of life. We further review the main factors shaping the infant microbiome- modes of delivery, feeding, weaning, and exposure to antibiotics. Taken together, we are starting to build a broader understanding of healthy vs. abnormal microbial alterations throughout major developmental time-points.

  10. Conjugation of metronidazole with dextran: a potential pharmaceutical strategy to control colonic distribution of the anti-amebic drug susceptible to metabolism by colonic microbes.

    Science.gov (United States)

    Kim, Wooseong; Yang, Yejin; Kim, Dohoon; Jeong, Seongkeun; Yoo, Jin-Wook; Yoon, Jeong-Hyun; Jung, Yunjin

    2017-01-01

    Metronidazole (MTDZ), the drug of choice for the treatment of protozoal infections such as luminal amebiasis, is highly susceptible to colonic metabolism, which may hinder its conversion from a colon-specific prodrug to an effective anti-amebic agent targeting the entire large intestine. Thus, in an attempt to control the colonic distribution of the drug, a polymeric colon-specific prodrug, MTDZ conjugated to dextran via a succinate linker (Dex-SA-MTDZ), was designed. Upon treatment with dextranase for 8 h, the degree of Dex-SA-MTDZ depolymerization (%) with a degree of substitution (mg of MTDZ bound in 100 mg of Dex-SA-MTDZ) of 7, 17, and 30 was 72, 38, and 8, respectively, while that of dextran was 85. Depolymerization of Dex-SA-MTDZ was found to be necessary for the release of MTDZ, because dextranase pretreatment ensures that de-esterification occurs between MTDZ and the dextran backbone. In parallel, Dex-SA-MTDZ with a degree of substitution of 17 was found not to release MTDZ upon incubation with the contents of the small intestine and stomach of rats, but it released MTDZ when incubated with rat cecal contents (including microbial dextranases). Moreover, Dex-SA-MTDZ exhibited prolonged release of MTDZ, which contrasts with drug release by small molecular colon-specific prodrugs, MTDZ sulfate and N -nicotinoyl-2-{2-(2-methyl-5-nitroimidazol-1-yl)ethyloxy}-d,l-glycine. These prodrugs were eliminated very rapidly, and no MTDZ was detected in the cecal contents. Consistent with these in vitro results, we found that oral gavage of Dex-SA-MTDZ delivered MTDZ (as MTDZ conjugated to [depolymerized] dextran) to the distal colon. However, upon oral gavage of the small molecular prodrugs, no prodrugs were detected in the distal colon. Collectively, these data suggest that dextran conjugation is a potential pharmaceutical strategy to control the colonic distribution of drugs susceptible to colonic microbial metabolism.

  11. Disturbance opens recruitment sites for bacterial colonization in activated sludge.

    Science.gov (United States)

    Vuono, David C; Munakata-Marr, Junko; Spear, John R; Drewes, Jörg E

    2016-01-01

    Little is known about the role of immigration in shaping bacterial communities or the factors that may dictate success or failure of colonization by bacteria from regional species pools. To address these knowledge gaps, the influence of bacterial colonization into an ecosystem (activated sludge bioreactor) was measured through a disturbance gradient (successive decreases in the parameter solids retention time) relative to stable operational conditions. Through a DNA sequencing approach, we show that the most abundant bacteria within the immigrant community have a greater probability of colonizing the receiving ecosystem, but mostly as low abundance community members. Only during the disturbance do some of these bacterial populations significantly increase in abundance beyond background levels and in few cases become dominant community members post-disturbance. Two mechanisms facilitate the enhanced enrichment of immigrant populations during disturbance: (i) the availability of resources left unconsumed by established species and (ii) the increased availability of niche space for colonizers to establish and displace resident populations. Thus, as a disturbance decreases local diversity, recruitment sites become available to promote colonization. This work advances our understanding of microbial resource management and diversity maintenance in complex ecosystems. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Plant colonization by pink-pigmented facultative methylotrophic bacteria (PPFMs).

    Science.gov (United States)

    Omer, Zahra S; Tombolini, Riccardo; Gerhardson, Berndt

    2004-03-01

    Bacteria belonging to the genus Methylobacterium are characterized by being able to rely on methanol as a sole carbon and energy source and by presenting a more or less intense pink reddish pigmentation. These bacteria, also referred to as pink-pigmented methylotrophic bacteria (PPFMs), are common inhabitants of the phyllosphere and are found in many other environmental samples. Since they grow slowly they are often overlooked and their impact on phyllosphere microbial communities and on the plants harboring them is not well studied nor has their ecology been elucidated. In a survey of PPFM colonization in three different agricultural sites, PPFM populations were identified on both red clover and winter wheat, but red clover was more consistently colonized. Isolations from collected leaves showed PPFM populations to decrease from spring towards summer, but they increased again towards the end of the cropping season. Isolates from red clover readily colonized winter wheat leaves and vice versa in greenhouse experiments, but population sizes were dependent on the application procedure. Tested isolates had also good potential to colonize the rhizosphere, especially after seed inoculations. Confocal scanning laser microscopy showed gfp-tagged isolates to colonize the surface of clover leaves by forming large aggregates.

  13. Outcomes of colon resection in patients with metastatic colon cancer.

    Science.gov (United States)

    Moghadamyeghaneh, Zhobin; Hanna, Mark H; Hwang, Grace; Mills, Steven; Pigazzi, Alessio; Stamos, Michael J; Carmichael, Joseph C

    2016-08-01

    Patients with advanced colorectal cancer have a high incidence of postoperative complications. We sought to identify outcomes of patients who underwent resection for colon cancer by cancer stage. The National Surgical Quality Improvement Program database was used to evaluate all patients who underwent colon resection with a diagnosis of colon cancer from 2012 to 2014. Multivariate logistic regression analysis was performed to investigate patient outcomes by cancer stage. A total of 7,786 colon cancer patients who underwent colon resection were identified. Of these, 10.8% had metastasis at the time of operation. Patients with metastatic disease had significantly increased risks of perioperative morbidity (adjusted odds ratio [AOR]: 1.44, P = .01) and mortality (AOR: 3.72, P = .01). Patients with metastatic disease were significantly younger (AOR: .99, P colon cancer have metastatic disease. Postoperative morbidity and mortality are significantly higher than in patients with localized disease. Published by Elsevier Inc.

  14. Microbes on a Bottle: Substrate, Season and Geography Influence Community Composition of Microbes Colonizing Marine Plastic Debris.

    Science.gov (United States)

    Oberbeckmann, Sonja; Osborn, A Mark; Duhaime, Melissa B

    2016-01-01

    Plastic debris pervades in our oceans and freshwater systems and the potential ecosystem-level impacts of this anthropogenic litter require urgent evaluation. Microbes readily colonize aquatic plastic debris and members of these biofilm communities are speculated to include pathogenic, toxic, invasive or plastic degrading-species. The influence of plastic-colonizing microorganisms on the fate of plastic debris is largely unknown, as is the role of plastic in selecting for unique microbial communities. This work aimed to characterize microbial biofilm communities colonizing single-use poly(ethylene terephthalate) (PET) drinking bottles, determine their plastic-specificity in contrast with seawater and glass-colonizing communities, and identify seasonal and geographical influences on the communities. A substrate recruitment experiment was established in which PET bottles were deployed for 5-6 weeks at three stations in the North Sea in three different seasons. The structure and composition of the PET-colonizing bacterial/archaeal and eukaryotic communities varied with season and station. Abundant PET-colonizing taxa belonged to the phylum Bacteroidetes (e.g. Flavobacteriaceae, Cryomorphaceae, Saprospiraceae-all known to degrade complex carbon substrates) and diatoms (e.g. Coscinodiscophytina, Bacillariophytina). The PET-colonizing microbial communities differed significantly from free-living communities, but from particle-associated (>3 μm) communities or those inhabiting glass substrates. These data suggest that microbial community assembly on plastics is driven by conventional marine biofilm processes, with the plastic surface serving as raft for attachment, rather than selecting for recruitment of plastic-specific microbial colonizers. A small proportion of taxa, notably, members of the Cryomorphaceae and Alcanivoraceae, were significantly discriminant of PET but not glass surfaces, conjuring the possibility that these groups may directly interact with the PET

  15. Microbes on a Bottle: Substrate, Season and Geography Influence Community Composition of Microbes Colonizing Marine Plastic Debris

    Science.gov (United States)

    Osborn, A. Mark

    2016-01-01

    Plastic debris pervades in our oceans and freshwater systems and the potential ecosystem-level impacts of this anthropogenic litter require urgent evaluation. Microbes readily colonize aquatic plastic debris and members of these biofilm communities are speculated to include pathogenic, toxic, invasive or plastic degrading-species. The influence of plastic-colonizing microorganisms on the fate of plastic debris is largely unknown, as is the role of plastic in selecting for unique microbial communities. This work aimed to characterize microbial biofilm communities colonizing single-use poly(ethylene terephthalate) (PET) drinking bottles, determine their plastic-specificity in contrast with seawater and glass-colonizing communities, and identify seasonal and geographical influences on the communities. A substrate recruitment experiment was established in which PET bottles were deployed for 5–6 weeks at three stations in the North Sea in three different seasons. The structure and composition of the PET-colonizing bacterial/archaeal and eukaryotic communities varied with season and station. Abundant PET-colonizing taxa belonged to the phylum Bacteroidetes (e.g. Flavobacteriaceae, Cryomorphaceae, Saprospiraceae—all known to degrade complex carbon substrates) and diatoms (e.g. Coscinodiscophytina, Bacillariophytina). The PET-colonizing microbial communities differed significantly from free-living communities, but from particle-associated (>3 μm) communities or those inhabiting glass substrates. These data suggest that microbial community assembly on plastics is driven by conventional marine biofilm processes, with the plastic surface serving as raft for attachment, rather than selecting for recruitment of plastic-specific microbial colonizers. A small proportion of taxa, notably, members of the Cryomorphaceae and Alcanivoraceae, were significantly discriminant of PET but not glass surfaces, conjuring the possibility that these groups may directly interact with the

  16. Microbes on a Bottle: Substrate, Season and Geography Influence Community Composition of Microbes Colonizing Marine Plastic Debris.

    Directory of Open Access Journals (Sweden)

    Sonja Oberbeckmann

    Full Text Available Plastic debris pervades in our oceans and freshwater systems and the potential ecosystem-level impacts of this anthropogenic litter require urgent evaluation. Microbes readily colonize aquatic plastic debris and members of these biofilm communities are speculated to include pathogenic, toxic, invasive or plastic degrading-species. The influence of plastic-colonizing microorganisms on the fate of plastic debris is largely unknown, as is the role of plastic in selecting for unique microbial communities. This work aimed to characterize microbial biofilm communities colonizing single-use poly(ethylene terephthalate (PET drinking bottles, determine their plastic-specificity in contrast with seawater and glass-colonizing communities, and identify seasonal and geographical influences on the communities. A substrate recruitment experiment was established in which PET bottles were deployed for 5-6 weeks at three stations in the North Sea in three different seasons. The structure and composition of the PET-colonizing bacterial/archaeal and eukaryotic communities varied with season and station. Abundant PET-colonizing taxa belonged to the phylum Bacteroidetes (e.g. Flavobacteriaceae, Cryomorphaceae, Saprospiraceae-all known to degrade complex carbon substrates and diatoms (e.g. Coscinodiscophytina, Bacillariophytina. The PET-colonizing microbial communities differed significantly from free-living communities, but from particle-associated (>3 μm communities or those inhabiting glass substrates. These data suggest that microbial community assembly on plastics is driven by conventional marine biofilm processes, with the plastic surface serving as raft for attachment, rather than selecting for recruitment of plastic-specific microbial colonizers. A small proportion of taxa, notably, members of the Cryomorphaceae and Alcanivoraceae, were significantly discriminant of PET but not glass surfaces, conjuring the possibility that these groups may directly interact

  17. Marine snow microbial communities: scaling of abundances with aggregate size

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2003-01-01

    Marine aggregates are inhabited by diverse microbial communities, and the concentration of attached microbes typically exceeds concentrations in the ambient water by orders of magnitude. An extension of the classical Lotka-Volterra model, which includes 3 trophic levels (bacteria, flagellates...... are controlled by flagellate grazing, while flagellate and ciliate populations are governed by colonization and detachment. The model also suggests that microbial populations are turned over rapidly (1 to 20 times d-1) due to continued colonization and detachment. The model overpredicts somewhat the scaling...... of microbial abundances with aggregate size observed in field-collected aggregates. This may be because it disregards the aggregation/disaggregation dynamics of aggregates, as well as interspecific interactions between bacteria....

  18. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading.......Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading....

  19. Dementia and driving

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000028.htm Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia , deciding when they can no longer drive may ...

  20. Gear bearing drive

    Science.gov (United States)

    Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor); Weinberg, Brian (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  1. Colonic motility and enema spreading

    International Nuclear Information System (INIS)

    Hardy, J.G.; Wood, E.; Clark, A.G.; Reynolds, J.R.; Queen's Medical Centre, Nottingham

    1986-01-01

    Radiolabelled enema solution was administered to eight healthy subjects, both in fasted and fed states. Enema spreading was monitored over a 4-h period using gamma scintigraphy and colonic motility was recorded simultaneously using a pressure sensitive radiotelemetry capsule. The rate and extent of enema dispersion were unaffected by eating. Spreading could be correlated with colonic motility and was inhibited by aboral propulsion of the colonic contents. (orig.)

  2. Vasohibin-1 suppresses colon cancer

    OpenAIRE

    Liu, Shuai; Han, Bing; Zhang, Qunyuan; Dou, Jie; Wang, Fang; Lin, Wenli; Sun, Yuping; Peng, Guangyong

    2015-01-01

    Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor. However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and co...

  3. Antihistamines and driving safety.

    Science.gov (United States)

    O'Hanlon, J F

    1988-10-27

    The results of two placebo-controlled driving performance studies confirm laboratory data showing that the nonsedating antihistamine terfenadine does not influence the driving performance of users. The amplitude of vehicle weaving calculated for drivers who received this agent did not differ from control values. Neither terfenadine nor loratadine, another nonsedating antihistamine, potentiated the adverse effects of alcohol on driving performance.

  4. Driving After a Stroke

    Science.gov (United States)

    ... 23,2015 Can I drive after a stroke? Driving is often a major concern after someone has a stroke. It’s not unusual for stroke survivors to want to drive. Being able to get around after a stroke is important. Safety behind the wheel is even more important after ...

  5. Sequential Dependencies in Driving

    Science.gov (United States)

    Doshi, Anup; Tran, Cuong; Wilder, Matthew H.; Mozer, Michael C.; Trivedi, Mohan M.

    2012-01-01

    The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find…

  6. Simple Driving Techniques

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    2002-01-01

    -like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data...

  7. Diffuse hemangioma of the colon

    International Nuclear Information System (INIS)

    Reis, J.; Caseiro-Alves, F.; Cruz, L.; Moreira, A.; Rebelo, O.

    1995-01-01

    We report two cases of diffuse hemangioma of the colon in adolescent patients. One patient had multiple phleboliths at the lower pelvis identified with plain radiographs of the abdomen. Several aspects were seen on double-contrast enema: luminal narrowing, colonic-wall thickening and submucosal colonic masses that changed in appearance with the degree of colonic distension. Angiography was inconclusive in one case. Use of CT and MR provided relevant information regarding the true extent of the disease, but MR was superior in demonstrating unequivocally the vascular nature of the lesions. (orig.)

  8. Estrogen inhibits chloride secretion caused by cholera and Escherichia coli enterotoxins in female rat distal colon.

    OpenAIRE

    Alzamora, Rodrigo; O'Mahony, Fiona; Harvey, Brian J

    2011-01-01

    Excessive Cl(-) secretion is the driving force for secretory diarrhea. 17β-Estradiol has been shown to inhibit Cl(-) secretion in rat distal colon through a nongenomic pathway. We examined whether 17β-estradiol inhibits Cl(-) secretion in an animal model of secretory diarrhea and the downstream effectors involved. The effect of 17β-estradiol on cholera toxin and heat-stable enterotoxin induced Cl(-) secretion in rat colonic mucosal sheets was studied by current-voltage clamping. Selective per...

  9. Hospitalized Premature Infants Are Colonized by Related Bacterial Strains with Distinct Proteomic Profiles

    Science.gov (United States)

    Xiong, Weili; Olm, Matthew R.; Thomas, Brian C.; Baker, Robyn; Firek, Brian; Morowitz, Michael J.; Hettich, Robert L.

    2018-01-01

    ABSTRACT During the first weeks of life, microbial colonization of the gut impacts human immune system maturation and other developmental processes. In premature infants, aberrant colonization has been implicated in the onset of necrotizing enterocolitis (NEC), a life-threatening intestinal disease. To study the premature infant gut colonization process, genome-resolved metagenomics was conducted on 343 fecal samples collected during the first 3 months of life from 35 premature infants housed in a neonatal intensive care unit, 14 of whom developed NEC, and metaproteomic measurements were made on 87 samples. Microbial community composition and proteomic profiles remained relatively stable on the time scale of a week, but the proteome was more variable. Although genetically similar organisms colonized many infants, most infants were colonized by distinct strains with metabolic profiles that could be distinguished using metaproteomics. Microbiome composition correlated with infant, antibiotics administration, and NEC diagnosis. Communities were found to cluster into seven primary types, and community type switched within infants, sometimes multiple times. Interestingly, some communities sampled from the same infant at subsequent time points clustered with those of other infants. In some cases, switches preceded onset of NEC; however, no species or community type could account for NEC across the majority of infants. In addition to a correlation of protein abundances with organism replication rates, we found that organism proteomes correlated with overall community composition. Thus, this genome-resolved proteomics study demonstrated that the contributions of individual organisms to microbiome development depend on microbial community context. PMID:29636439

  10. Hospitalized Premature Infants Are Colonized by Related Bacterial Strains with Distinct Proteomic Profiles

    Directory of Open Access Journals (Sweden)

    Christopher T. Brown

    2018-04-01

    Full Text Available During the first weeks of life, microbial colonization of the gut impacts human immune system maturation and other developmental processes. In premature infants, aberrant colonization has been implicated in the onset of necrotizing enterocolitis (NEC, a life-threatening intestinal disease. To study the premature infant gut colonization process, genome-resolved metagenomics was conducted on 343 fecal samples collected during the first 3 months of life from 35 premature infants housed in a neonatal intensive care unit, 14 of whom developed NEC, and metaproteomic measurements were made on 87 samples. Microbial community composition and proteomic profiles remained relatively stable on the time scale of a week, but the proteome was more variable. Although genetically similar organisms colonized many infants, most infants were colonized by distinct strains with metabolic profiles that could be distinguished using metaproteomics. Microbiome composition correlated with infant, antibiotics administration, and NEC diagnosis. Communities were found to cluster into seven primary types, and community type switched within infants, sometimes multiple times. Interestingly, some communities sampled from the same infant at subsequent time points clustered with those of other infants. In some cases, switches preceded onset of NEC; however, no species or community type could account for NEC across the majority of infants. In addition to a correlation of protein abundances with organism replication rates, we found that organism proteomes correlated with overall community composition. Thus, this genome-resolved proteomics study demonstrated that the contributions of individual organisms to microbiome development depend on microbial community context.

  11. MALToma of the Transverse colon, Ascending colon and Caecum: A ...

    African Journals Online (AJOL)

    TNHJOURNALPH

    RESULT. We herein report a case of a 40-year-old male with mucosa - associated lymphoid tissue. [MALT] lymphoma of the transverse colon, ascending colon and caecum. He presented with severe abdominal pains and a centrally located huge abdominal mass for which a surgical resection was done. Histologically.

  12. Endogenous Antimicrobial Peptide Expression in Response to Bacterial Epidermal Colonization

    Directory of Open Access Journals (Sweden)

    Michael Brandwein

    2017-11-01

    Full Text Available Bacterial commensal colonization of human skin is vital for the training and maintenance of the skin’s innate and adaptive immune functions. In addition to its physical barrier against pathogen colonization, the skin expresses a variety of antimicrobial peptides (AMPs which are expressed constitutively and induced in response to pathogenic microbial stimuli. These AMPs are differentially effective against a suite of microbial skin colonizers, including both bacterial and fungal residents of the skin. We review the breadth of microorganism-induced cutaneous AMP expression studies and their complementary findings on the efficacy of skin AMPs against different bacterial and fungal species. We suggest further directions for skin AMP research based on emerging skin microbiome knowledge in an effort to advance our understanding of the nuanced host–microbe balance on human skin. Such advances should enable the scientific community to bridge the gap between descriptive disease-state AMP studies and experimental single-species in vitro studies, thereby enabling research endeavors that more closely mimic the natural skin environs.

  13. Colonic duplication in an adult

    International Nuclear Information System (INIS)

    Baro, P.; Dario Casas, J.; Sanchez, D.

    1988-01-01

    A case of colonic duplication that was diagnosed radiologically in an adult is reported. A long duplicated segment below the normal transverse colon, with a wide anastomosis at the hepatic flexure level, was observed on barium enema. The rarity of this anomaly unassociated with other malformations is emphasized. (orig.)

  14. Prehistoric human colonization of India

    Indian Academy of Sciences (India)

    Unknown

    2. Earliest human colonization of south Asia. The early human colonization of south Asia is represented largely by an abundance of stone tool assemblages. The oldest known tools ..... component among finished tools is conspicuous in the hinterland riverine ...... sativum), green gram (Vigna radiata), gram/chicken pea.

  15. Colonic Diverticulitis in the Elderly

    Directory of Open Access Journals (Sweden)

    Chien-Kuo Liu

    2009-03-01

    Full Text Available Diverticular disease of the colon is a disease that mainly affects the elderly and presents in 50–70% of those aged 80 years or older. The most common complication is colonic diverticulitis. Eighty percent of patients who present with colonic diverticulitis are aged 50 years and older. Diagnosis and treatment of colonic diverticulitis in the elderly is more difficult and complicated owing to more comorbid conditions. Computed tomography is recommended for diagnosis when colonic diverticulitis is suspected. Most patients admitted with acute colonic diverticulitis respond to conservative treatment, but 15–30% of patients require surgery. Because surgery for acute colonic diverticulitis carries significant rates of morbidity and mortality, conservative treatment is recommended in the elderly. Conservative treatment of colonic diverticulitis with antibiotics, bowel rest, possibly including parenteral alimentation, is usually applied for 1–2 weeks. In the absence of a response to conservative treatment, frequent recurrence or complications (abscesses, fistulas, bowel obstructions, and free perforations, surgery is indicated.

  16. Colonic perforation following endoscopic retrograde ...

    African Journals Online (AJOL)

    She developed severe upper abdominal pain after the ... non-surgical management of pancreatitis and associated complications, colonic perforation should be considered in patients who deteriorate ... To our knowledge this is the first case of a secure pre-operative diagnosis of colonic perforation due to to pancreatitis.

  17. Control rod drive

    International Nuclear Information System (INIS)

    Okutani, Tetsuro.

    1988-01-01

    Purpose: To provide a simple and economical control rod drive using a control circuit requiring no pulse circuit. Constitution: Control rods in a BWR type reactor are driven by hydraulic pressure and inserted or withdrawn in the direction of applying the hydraulic pressure. The direction of the hydraulic pressure is controlled by a direction control valve. Since the driving for the control rod is extremely important in view of the operation, a self diagnosis function is disposed for rapid inspection of possible abnormality. In the present invention, two driving contacts are disposed each by one between the both ends of a solenoid valve of the direction control valve for driving the control rod and the driving power source, and diagnosis is conducted by alternately operating them. Therefore, since it is only necessary that the control circuit issues a driving instruction only to one of the two driving contacts, the pulse circuit is no more required. Further, since the control rod driving is conducted upon alignment of the two driving instructions, the reliability of the control rod drive can be improved. (Horiuchi, T.)

  18. Microbial micropatches within microbial hotspots

    Science.gov (United States)

    Smith, Renee J.; Tobe, Shanan S.; Paterson, James S.; Seymour, Justin R.; Oliver, Rod L.; Mitchell, James G.

    2018-01-01

    The spatial distributions of organism abundance and diversity are often heterogeneous. This includes the sub-centimetre distributions of microbes, which have ‘hotspots’ of high abundance, and ‘coldspots’ of low abundance. Previously we showed that 300 μl abundance hotspots, coldspots and background regions were distinct at all taxonomic levels. Here we build on these results by showing taxonomic micropatches within these 300 μl microscale hotspots, coldspots and background regions at the 1 μl scale. This heterogeneity among 1 μl subsamples was driven by heightened abundance of specific genera. The micropatches were most pronounced within hotspots. Micropatches were dominated by Pseudomonas, Bacteroides, Parasporobacterium and Lachnospiraceae incertae sedis, with Pseudomonas and Bacteroides being responsible for a shift in the most dominant genera in individual hotspot subsamples, representing up to 80.6% and 47.3% average abundance, respectively. The presence of these micropatches implies the ability these groups have to create, establish themselves in, or exploit heterogeneous microenvironments. These genera are often particle-associated, from which we infer that these micropatches are evidence for sub-millimetre aggregates and the aquatic polymer matrix. These findings support the emerging paradigm that the microscale distributions of planktonic microbes are numerically and taxonomically heterogeneous at scales of millimetres and less. We show that microscale microbial hotspots have internal structure within which specific local nutrient exchanges and cellular interactions might occur. PMID:29787564

  19. Microbes on a bottle: substrate, season and geography influence community composition of microbes colonizing marine plastic debris

    OpenAIRE

    Carter, Dee A.; Oberbeckmann, Sonja; Osborn, A. Mark; Duhaime, Melissa B.

    2016-01-01

    Plastic debris pervades in our oceans and freshwater systems and the potential ecosystem-level impacts of this anthropogenic litter require urgent evaluation. Microbes readily colonize aquatic plastic debris and members of these biofilm communities are speculated to include pathogenic, toxic, invasive or plastic degrading-species. The influence of plastic-colonizing microorganisms on the fate of plastic debris is largely unknown, as is the role of plastic in selecting for unique microbial com...

  20. Transported biofilms and their influence on subsequent macrofouling colonization.

    Science.gov (United States)

    Sweat, L Holly; Swain, Geoffrey W; Hunsucker, Kelli Z; Johnson, Kevin B

    2017-05-01

    Biofilm organisms such as diatoms are potential regulators of global macrofouling dispersal because they ubiquitously colonize submerged surfaces, resist antifouling efforts and frequently alter larval recruitment. Although ships continually deliver biofilms to foreign ports, it is unclear how transport shapes biofilm microbial structure and subsequent macrofouling colonization. This study demonstrates that different ship hull coatings and transport methods change diatom assemblage composition in transported coastal marine biofilms. Assemblages carried on the hull experienced significant cell losses and changes in composition through hydrodynamic stress, whereas those that underwent sheltered transport, even through freshwater, were largely unaltered. Coatings and their associated biofilms shaped distinct macrofouling communities and affected recruitment for one third of all species, while biofilms from different transport treatments had little effect on macrofouling colonization. These results demonstrate that transport conditions can shape diatom assemblages in biofilms carried by ships, but the properties of the underlying coatings are mainly responsible for subsequent macrofouling. The methods by which organisms colonize and are transferred by ships have implications for their distribution, establishment and invasion success.

  1. Using driving simulators to assess driving safety.

    Science.gov (United States)

    Boyle, Linda Ng; Lee, John D

    2010-05-01

    Changes in drivers, vehicles, and roadways pose substantial challenges to the transportation safety community. Crash records and naturalistic driving data are useful for examining the influence of past or existing technology on drivers, and the associations between risk factors and crashes. However, they are limited because causation cannot be established and technology not yet installed in production vehicles cannot be assessed. Driving simulators have become an increasingly widespread tool to understand evolving and novel technologies. The ability to manipulate independent variables in a randomized, controlled setting also provides the added benefit of identifying causal links. This paper introduces a special issue on simulator-based safety studies. The special issue comprises 25 papers that demonstrate the use of driving simulators to address pressing transportation safety problems and includes topics as diverse as neurological dysfunction, work zone design, and driver distraction. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  2. Plant genotype, microbial recruitment and nutritional security.

    Science.gov (United States)

    Patel, Jai S; Singh, Akanksha; Singh, Harikesh B; Sarma, Birinchi K

    2015-01-01

    Agricultural food products with high nutritional value should always be preferred over food products with low nutritional value. Efforts are being made to increase nutritional value of food by incorporating dietary supplements to the food products. The same is more desirous if the nutritional value of food is increased under natural environmental conditions especially in agricultural farms. Fragmented researches have demonstrated possibilities in achieving the same. The rhizosphere is vital in this regard for not only health and nutritional status of plants but also for the microorganisms colonizing the rhizosphere. Remarkably robust composition of plant microbiome with respect to other soil environments clearly suggests the role of a plant host in discriminating its colonizers (Zancarini et al., 2012). A large number of biotic and abiotic factors are believed to manipulate the microbial communities in the rhizosphere. However, plant genotype has proven to be the key in giving the final shape of the rhizosphere microbiome (Berendsen et al., 2012; Marques et al., 2014).

  3. Microbial programming of health and disease starts during fetal life.

    Science.gov (United States)

    Koleva, Petya T; Kim, Ji-Sun; Scott, James A; Kozyrskyj, Anita L

    2015-12-01

    The pioneer microbiota of the neonatal gut are essential for gut maturation, and metabolic and immunologic programming. Recent research has shown that early bacterial colonization may impact the occurrence of disease later in life (microbial programming). Despite early conflicting evidence, it has long been considered that the womb is a sterile environment and human microbial colonization begins at birth. In the last few years, several findings have reiterated the presence of microbes in infant first stool (meconium) and pointed to the existence of in utero microbial colonization of the infant gut. The dominant bacterial taxa detected in meconium specimens belong to the Enterobacteriaceae family (Escherichia genus) and lactic acid bacteria (notably members of the genera Leuconostoc, Enterococcus, and Lactococcus). Maternal atopy promotes dominance of Enterobacteriaceae in newborn meconium, which in turn may lead to respiratory problems in the infant. This microbial interaction with the host immune system may in fact, originate during fetal life. Our review evaluates the evidence for an intrauterine origin of meconium microbiota, their composition and influences, and potential clinical implications on infant health. © 2015 Wiley Periodicals, Inc.

  4. Superluminal warp drive

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Diaz, Pedro F. [Colina de los Chopos, Centro de Fisica ' Miguel A. Catalan' , Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)], E-mail: p.gonzalezdiaz@imaff.cfmac.csic.es

    2007-09-20

    In this Letter we consider a warp drive spacetime resulting from that suggested by Alcubierre when the spaceship can only travel faster than light. Restricting to the two dimensions that retains most of the physics, we derive the thermodynamic properties of the warp drive and show that the temperature of the spaceship rises up as its apparent velocity increases. We also find that the warp drive spacetime can be exhibited in a manifestly cosmological form.

  5. Microbial degradation of water-insoluble organic compounds

    International Nuclear Information System (INIS)

    Thomas, J.M.

    1985-01-01

    The effect of solubilization on biodegradation of water-insoluble organic compounds was investigated. The effect of particle size on solubilization and degradation of 4-chlorobiphenyl (4-CB) and naphthalene by a microbial mixture was determined. The concentration of soluble compound was determined using gas-liquid chromatography. The rates of solubilization were inversely related to particle size for both compounds. The rates of mineralization of 14 C-labeled palmitic acid, octadecane, di(2-ethylhexyl)phthalate (DEHP), and Sevin (1-naphthyl N-methylcarbamate) by microbial mixtures were determined by trapping the 14 CO 2 formed, and those rates were compared to solubilization rates determined by periodically filtering sterile MS amended with one of the compounds. Mineralization and colonization of the surface of 10 μg palmitic acid per 10 ml MS by Pseudomonas pseudoflava was determined by trapping 14 CO 2 and epifluorescence microscopy. Mineralization began before colonization and was initially exponential, but the rate then declined. The rate of mineralization at the end of the exponential phase approximated the rate of solubilization. The surface was completely covered about the time mineralization stopped. Unbound cells grew exponentially before colonization was detected; however, colonization of the surface was complete after the number of free cells stopped increasing. The data suggest that soluble palmitic acid is utilized before the insoluble phase but colonization is important in the mineralization of palmitic acid when solubilization becomes rate limiting

  6. Medications and impaired driving.

    Science.gov (United States)

    Hetland, Amanda; Carr, David B

    2014-04-01

    To describe the association of specific medication classes with driving outcomes and provide clinical recommendations. The MEDLINE and EMBASE databases were searched for articles published from January 1973 to June 2013 on classes of medications associated with driving impairment. The search included outcome terms such as automobile driving, motor vehicle crash, driving simulator, and road tests. Only English-language articles that contained findings from observational or interventional designs with ≥ 10 participants were included in this review. Cross-sectional studies, case series, and case reports were excluded. Driving is an important task and activity for the majority of adults. Some commonly prescribed medications have been associated with driving impairment measured by road performance, driving simulation, and/or motor vehicle crashes. This review of 30 studies identified findings with barbiturates, benzodiazepines, hypnotics, antidepressants, opioid and nonsteroidal analgesics, anticonvulsants, antipsychotics, antiparkinsonian agents, skeletal muscle relaxants, antihistamines, anticholinergic medications, and hypoglycemic agents. Additional studies of medication impact on sedation, sleep latency, and psychomotor function, as well as the role of alcohol, are also discussed. Psychotropic agents and those with central nervous system side effects were associated with measures of impaired driving performance. It is difficult to determine if such associations are actually a result of medication use or the medical diagnosis itself. Regardless, clinicians should be aware of the increased risk of impaired driving with specific classes of medications, educate their patients, and/or consider safer alternatives.

  7. Universal Drive Train Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  8. The Microbial Engines That Drive Earth’s Biogeochemical Cycles

    Science.gov (United States)

    Falkowski, Paul G.; Fenchel, Tom; Delong, Edward F.

    2008-05-01

    Virtually all nonequilibrium electron transfers on Earth are driven by a set of nanobiological machines composed largely of multimeric protein complexes associated with a small number of prosthetic groups. These machines evolved exclusively in microbes early in our planet’s history yet, despite their antiquity, are highly conserved. Hence, although there is enormous genetic diversity in nature, there remains a relatively stable set of core genes coding for the major redox reactions essential for life and biogeochemical cycles. These genes created and coevolved with biogeochemical cycles and were passed from microbe to microbe primarily by horizontal gene transfer. A major challenge in the coming decades is to understand how these machines evolved, how they work, and the processes that control their activity on both molecular and planetary scales.

  9. Engineering chemical interactions in microbial communities.

    Science.gov (United States)

    Kenny, Douglas J; Balskus, Emily P

    2018-03-05

    Microbes living within host-associated microbial communities (microbiotas) rely on chemical communication to interact with surrounding organisms. These interactions serve many purposes, from supplying the multicellular host with nutrients to antagonizing invading pathogens, and breakdown of chemical signaling has potentially negative consequences for both the host and microbiota. Efforts to engineer microbes to take part in chemical interactions represent a promising strategy for modulating chemical signaling within these complex communities. In this review, we discuss prominent examples of chemical interactions found within host-associated microbial communities, with an emphasis on the plant-root microbiota and the intestinal microbiota of animals. We then highlight how an understanding of such interactions has guided efforts to engineer microbes to participate in chemical signaling in these habitats. We discuss engineering efforts in the context of chemical interactions that enable host colonization, promote host health, and exclude pathogens. Finally, we describe prominent challenges facing this field and propose new directions for future engineering efforts.

  10. Diverticulosis of colon: Case report

    International Nuclear Information System (INIS)

    Han, Chang Yul

    1972-01-01

    The authors reports 2 cases of diverticulosis involving the sacending colon and cecum: one, 55 year old, 85 kg Korean male admitted to Paik Hospital because of abdominal palm, constipation and tenderness in the right lower abdomen. The other, 48 year old, 78 kg male visited to our hospital for the routine examination. According to late European and American statistics, the colonic diverticulosis was discovered in late middle life about 20%, however, the incidence of colonic diverticulosis is rare in Korea. This paper presents a brief review of literature on the etiology, incidence and symptom

  11. Vasohibin-1 suppresses colon cancer

    Science.gov (United States)

    Liu, Shuai; Han, Bing; Zhang, Qunyuan; Dou, Jie; Wang, Fang; Lin, Wenli; Sun, Yuping; Peng, Guangyong

    2015-01-01

    Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor. However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and colony formation in vitro and tumor growth in vivo. In addition, knockdown of VASH1 in cancer cells promoted cell growth, adhesion and migration in vitro, and enhanced tumorigenesis and metastasis in vivo. PMID:25797264

  12. Colonic motility in proctalgia fugax.

    Science.gov (United States)

    Harvey, R F

    1979-10-06

    Intraluminal pressure recordings were obtained from the rectum and sigmoid colon in two patients experiencing attacks of proctalgia fugax. In each patient the pain appeared to result from contractions of the sigmoid colon, and not from spasm of the levator ani, rectal wall muscle, or anal sphincters, all of which have previously been suggested as the source of such pain. Proctalgia fugax therefore appears, at least in some patients, to be an unusual variant of the irritable bowel syndrome, in which pain is referred from the sigmoid colon to the rectum.

  13. Vasohibin-1 suppresses colon cancer.

    Science.gov (United States)

    Liu, Shuai; Han, Bing; Zhang, Qunyuan; Dou, Jie; Wang, Fang; Lin, Wenli; Sun, Yuping; Peng, Guangyong

    2015-04-10

    Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor.However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and colony formation in vitro and tumor growth in vivo. In addition, knockdown of VASH1 in cancer cells promoted cell growth, adhesion and migration in vitro, and enhanced tumorigenesis and metastasis in vivo.

  14. Immune Response of Chicken Gut to Natural Colonization by Gut Microflora and to Salmonella enterica Serovar Enteritidis Infection ▿

    OpenAIRE

    Crhanova, Magdalena; Hradecka, Helena; Faldynova, Marcela; Matulova, Marta; Havlickova, Hana; Sisak, Frantisek; Rychlik, Ivan

    2011-01-01

    In commercial poultry production, there is a lack of natural flora providers since chickens are hatched in the clean environment of a hatchery. Events occurring soon after hatching are therefore of particular importance, and that is why we were interested in the development of the gut microbial community, the immune response to natural microbial colonization, and the response to Salmonella enterica serovar Enteritidis infection as a function of chicken age. The complexity of chicken gut micro...

  15. 11 Soil Microbial Biomass

    African Journals Online (AJOL)

    186–198. Insam H. (1990). Are the soil microbial biomass and basal respiration governed by the climatic regime? Soil. Biol. Biochem. 22: 525–532. Insam H. D. and Domsch K. H. (1989). Influence of microclimate on soil microbial biomass. Soil Biol. Biochem. 21: 211–21. Jenkinson D. S. (1988). Determination of microbial.

  16. Molecular microbial ecology manual

    NARCIS (Netherlands)

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

    2004-01-01

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

  17. Microbial Rechargeable Battery

    NARCIS (Netherlands)

    Molenaar, Sam D.; Mol, Annemerel R.; Sleutels, Tom H.J.A.; Heijne, Ter Annemiek; Buisman, Cees J.N.

    2016-01-01

    Bioelectrochemical systems hold potential for both conversion of electricity into chemicals through microbial electrosynthesis (MES) and the provision of electrical power by oxidation of organics using microbial fuel cells (MFCs). This study provides a proof of concept for a microbial

  18. Childhood microbial keratitis

    Directory of Open Access Journals (Sweden)

    Abdullah G Al Otaibi

    2012-01-01

    Conclusion: Children with suspected microbial keratitis require comprehensive evaluation and management. Early recognition, identifying the predisposing factors and etiological microbial organisms, and instituting appropriate treatment measures have a crucial role in outcome. Ocular trauma was the leading cause of childhood microbial keratitis in our study.

  19. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  20. Wrong-way driving.

    NARCIS (Netherlands)

    2006-01-01

    Wrong-way driving is a phenomenon that mainly happens on motorways. Although the number of wrong-way crashes is relatively limited, their consequences are much more severe than the consequences of other motorway injury crashes. The groups most often causing wrong-way driving accidents are young,

  1. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't

  2. Control rod drives

    International Nuclear Information System (INIS)

    Futatsugi, Masao.

    1980-01-01

    Purpose: To secure the reactor operation safety by the provision of a fluid pressure detecting section for control rod driving fluid and a control rod interlock at the midway of the flow pass for supplying driving fluid to the control rod drives. Constitution: Between a driving line and a direction control valve are provided a pressure detecting portion, an alarm generating device, and a control rod inhibition interlock. The driving fluid from a driving fluid source is discharged by way of a pump and a manual valve into the reactor in which the control rods and reactor fuels are contained. In addition, when the direction control valve is switched and the control rods are inserted and extracted by the control rod drives, the pressure in the driving line is always detected by the pressure detection section, whereby if abnormal pressure is resulted, the alarm generating device is actuated to warn the abnormality and the control rod inhibition interlock is actuated to lock the direction control valve thereby secure the safety operation of the reactor. (Seki, T.)

  3. Switched reluctance motor drives

    Indian Academy of Sciences (India)

    Davis RM, Ray WF, Blake RJ 1981 Inverter drive for switched reluctance: circuits and component ratings. Inst. Elec. Eng. Proc. B128: 126-136. Ehsani M. 1991 Position Sensor elimination technique for the switched reluctance motor drive. US Patent No. 5,072,166. Ehsani M, Ramani K R 1993 Direct control strategies based ...

  4. Self-driving carsickness

    NARCIS (Netherlands)

    Diels, C.; Bos, J.E.

    2016-01-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and

  5. Self-driving carsickness.

    NARCIS (Netherlands)

    Diels, C.; Bos, J.E.

    2016-01-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and

  6. Fundamentals of electrical drives

    CERN Document Server

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  7. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  8. Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls

    Science.gov (United States)

    Kallenbach, Cynthia M.; Frey, Serita D.; Grandy, A. Stuart

    2016-11-01

    Soil organic matter (SOM) and the carbon and nutrients therein drive fundamental submicron- to global-scale biogeochemical processes and influence carbon-climate feedbacks. Consensus is emerging that microbial materials are an important constituent of stable SOM, and new conceptual and quantitative SOM models are rapidly incorporating this view. However, direct evidence demonstrating that microbial residues account for the chemistry, stability and abundance of SOM is still lacking. Further, emerging models emphasize the stabilization of microbial-derived SOM by abiotic mechanisms, while the effects of microbial physiology on microbial residue production remain unclear. Here we provide the first direct evidence that soil microbes produce chemically diverse, stable SOM. We show that SOM accumulation is driven by distinct microbial communities more so than clay mineralogy, where microbial-derived SOM accumulation is greatest in soils with higher fungal abundances and more efficient microbial biomass production.

  9. Colonization of overlaying water by bacteria from dry river sediments.

    Science.gov (United States)

    Fazi, Stefano; Amalfitano, Stefano; Piccini, Claudia; Zoppini, Annamaria; Puddu, Alberto; Pernthaler, Jakob

    2008-10-01

    We studied the diversity, community composition and activity of the primary microbial colonizers of the water above freshly re-wetted sediments from a temporary river. Dried sediments, collected from Mulargia River (Sardinia, Italy), were covered with sterile freshwater in triplicate microcosms, and changes of the planktonic microbial assemblage were monitored over a 48 h period. During the first 9 h bacterial abundance was low (1.5 x 10(4) cells ml(-1)); it increased to 3.4 x 10(6) cells ml(-1) after 28 h and did not change thereafter. Approximately 20% of bacteria exhibited DNA de novo synthesis already after 9 h of incubation. Changes of the ratios of (3)H-leucine to (3)H-thymidine incorporation rates indicated a shift of growth patterns during the experiment. Extracellular enzyme activity showed a maximum at 48 h with aminopeptidase activity (430.8 +/- 22.6 nmol MCA l(-1) h(-1)) significantly higher than alkaline phosphatase (98.6 +/- 4.3 nmol MUF l(-1) h(-1)). The primary microbial colonizers of the overlaying water - as determined by 16S rRNA gene sequence analysis - were related to at least six different phylogenetic lineages of Bacilli and to Alphaproteobacteria (Brevundimonas spp. and Caulobacter spp.). Large bacterial cells affiliated to one clade of Bacillus sp. were rare in the dried sediments, but constituted the majority of the planktonic microbial assemblage and of cells with detectable DNA-synthesis until 28 h after re-wetting. Their community contribution decreased in parallel with a rise of flagellated and ciliated protists. Estimates based on cell production rates suggested that the rapidly enriched Bacillus sp. suffered disproportionally high loss rates from selective predation, thus favouring the establishment of a more heterogenic assemblage of microbes (consisting of Proteobacteria, Actinobacteria and Cytophaga-Flavobacteria). Our results suggest that the primary microbial colonizers of the water above dried sediments are passively released

  10. Control rod drives

    International Nuclear Information System (INIS)

    Nakamura, Akira.

    1984-01-01

    Purpose: To enable to monitor the coupling state between a control rod and a control rod drive. Constitution: After the completion of a control rod withdrawal, a coolant pressure is applied to a control rod drive being adjusted so as to raise only the control rod drive and, in a case where the coupling between the control rod drive and the control rod is detached, the former is elevated till it contacts the control rod and then stopped. The actual stopping position is detected by an actual position detection circuit and compared with a predetermined position stored in a predetermined position detection circuit. If both of the positions are not aligned with each other, it is judged by a judging circuit that the control rod and the control rod drives are not combined. (Sekiya, K.)

  11. Colonization and environment

    International Nuclear Information System (INIS)

    Garcia Gutierrez, E.

    1999-01-01

    It stands out the man's paper in the deterioration of the soil and in the phenomenon of the desertization, the conflicts of the use of the soil in the country and the underestimate that it is made of this resource in the environmental analysis. The man's relationships are discussed with the earth and the problem of the soils of the Colombian Orinoquia is examined in terms of the excess of toxic elements as To the, Fe and Mn and the other elements like P, S, Ca, Mg, K, B, and Zn. It is examined the degradation and poverty of the organic complex of the soil, the physical degradation and chemistry and their susceptibility to the erosion, as well as the excess conditions and deficit of humidity. It is recognized that it lacks calibration of the analytic methods for the soils oxisoils of the Orinoquia and the Amazonia. The importance of the soils of the humid tropic is stood out as seat of colonization that have failed when not having an appropriate technology for its handling that it forces to undertake systems of migratory agriculture and to the transformation of the forest in prairie, phenomenon that comes accompanied by the degradation of the soils, illicit cultivations, social conflicts and alteration of the essential ecological processes for the survival

  12. Microbial electrosynthesis of hydrogen peroxide in microbial reverse-electrodialysis electrolysis cell

    DEFF Research Database (Denmark)

    Li, Xiaohu; Angelidaki, Irini; Zhang, Yifeng

    2016-01-01

    Microbial reverse-electrodialysis electrolysis cell (MREC) as a novel type of microbial electrochemical technologies has been proposed to produce H2 and CH4. In this study, we developed MREC to produce the strong oxidant H2O2. In the MREC, electrical potential generated by the exoelectrogens...... and the salinity-gradient between sea water and river water were utilized to drive the high-rate H2O2 production without external power supply. Operational parameters such as air flow rate, pH, cathodic potential, flow rate of high and low concentration solution were investigated. The optimal H2O2 production were...

  13. Distal, not proximal, colonic acetate infusions promote fat oxidation and improve metabolic markers in overweight/obese men

    DEFF Research Database (Denmark)

    van der Beek, Christina M; Canfora, Emanuel E; Lenaerts, Kaatje

    2016-01-01

    , circulating hormones or inflammatory markers. In conclusion distal colonic acetate infusions affected whole-body substrate metabolism, with a pronounced increase in fasting fat oxidation and plasma PYY. Modulating colonic acetate may be a nutritional target to treat or prevent metabolic disorders.......Gut microbial-derived short-chain fatty acids (SCFA) are believed to affect host metabolism and cardiometabolic risk factors. The present study aim was to investigate the effects of proximal and distal colonic infusions with the SCFA acetate on fat oxidation and other metabolic parameters in men...... in the colon for three consecutive test days, enabling colonic acetate (100 or 180 mmol/l) or placebo infusion during fasting conditions and after an oral glucose load (postprandial). Fat oxidation and energy expenditure were measured using an open-circuit ventilated hood system and blood samples were...

  14. Multidetector CT of the colon

    International Nuclear Information System (INIS)

    Luboldt, W.; Hoepffner, N.; Holzer, K.

    2003-01-01

    Multidetector technology, enabling faster imaging, higher spatial resolution and reduction in radiation dose, increases the role of CT in colonic diagnostic. The higher spatial resolution in the z-direction also changes the way to analyze the images. Instead of reading axial sections, now the colon can be systematically assessed in 3D by scrolling through multiplanar reconstructions or in CT colonography by virtual endoscopy. With ongoing improvements in computer-aided diagnosis CT colonography becomes an alternative to fiberoptic colonocopy for screening (http://www.multiorganscreening.org). In this article we propose a CT examination protocol for the colon, describe the typical imaging findings of different colonic diseases, and summarize the current status of CT colonography. (orig.)

  15. Understanding your colon cancer risk

    Science.gov (United States)

    ... for women and 2 drinks per day for men DO NOT smoke You can also have genetic testing done to assess your risk for colon cancer. If you have a strong family history of the disease, talk with your ...

  16. Colon Cleansing: Health or Hype?

    Science.gov (United States)

    ... cramps Dizziness Dehydration Bowel perforation Infection Depletion of probiotics, sodium and potassium Kidney damage Plus, colon cleansing ... goodbye to bacon, sausage, deli meats and hot dogs. Cancer-causing substances form when meats are preserved. ...

  17. Primary closure in colon trauma.

    Science.gov (United States)

    Salinas-Aragón, Luis Enrique; Guevara-Torres, Lorenzo; Vaca-Pérez, Enrique; Belmares-Taboada, Jaime Arístides; Ortiz-Castillo, Fátima de Guadalupe; Sánchez-Aguilar, Martín

    2009-01-01

    Primary repair of colon injuries is an accepted therapeutic option; however, controversy persists regarding its safety. Our objective was to report the evolution and presence of complications in patients with colon injury who underwent primary closure and to determine if the time interval (>6 h), degree of injury, contamination, anatomic site injured, PATI (Penetrating Abdominal Trauma Index) >25, and the presence of other injuries in colon trauma are associated with increased morbidity and mortality. This was a prospective, observational, longitudinal and descriptive study conducted at the Central Hospital "Dr. Ignacio Morones Prieto," San Luis Potosí, Mexico, from January 1, 2003 to December 31, 2007. We included patients with abdominal trauma with colon injury subjected to surgical treatment. chi(2) was used for basic statistical analysis. There were 481 patients with abdominal trauma who underwent surgery; 77(16.1%) had colon injury. Ninety percent (n = 69) were treated in the first 6 h; 91% (n = 70) were due to penetrating injuries, and gunshot wound accounted for 48% (n = 37). Transverse colon was the most frequently injured (38%) (n = 29). Grade I and II injuries accounted for 75.3% (n = 58). Procedures included primary repair (76.66 %) (n = 46); resection with anastomosis (8.3%) (n = 5); and colostomy (15%) (n = 9). Associated injuries were present in 76.6% (n = 59). There was some degree of contamination in 85.7% (n = 66); 82.8% (58) had PATI colon injury. Primary repair is a safe procedure for treatment of colon injuries. Patients with primary repair had lower morbidity (p <0.009). Surgery during the first 6 h (p <0.006) and in hemodynamically stable patients (p <0.014) had a lower risk of complications.

  18. Gastrointestinal microbial ecology and its health benefits in Dogs

    Directory of Open Access Journals (Sweden)

    K.B. Kore

    2010-06-01

    Full Text Available Gastrointestinal microbial balance is the most important prerequisite for normal functions of digestive system, physiological and immunological homeostasis in dogs as well as in other animals. It helps in prevention of pathogenic colonization, provides energy through SCFA by nutrient breakdown, and improves mineral-vitamin supply to host, augment host immune status. Hence, it is imperative to explore the potential means to improve the gastrointestinal microbial diversity which in turns boost up dog health. [Vet. World 2010; 3(3.000: 140-141

  19. Colon in acute intestinal infection.

    Science.gov (United States)

    Guarino, Alfredo; Buccigrossi, Vittoria; Armellino, Carla

    2009-04-01

    The colon is actively implicated in intestinal infections not only as a target of enteric pathogens and their products but also as a target organ for treatment. In the presence of diarrhea, both of osmotic and secretory nature, the colon reacts with homeostatic mechanisms to increase ion absorption. These mechanisms can be effectively exploited to decrease fluid discharge. A model of intestinal infections using rotavirus (RV) in colonic cells was set up and used to define a dual model of secretory and osmotic diarrhea in sequence. Using this model, antidiarrheal drugs were tested, namely zinc and the enkephalinase inhibitor racecadotril. Zinc was able to decrease the enterotoxic activity responsible for secretory diarrhea. It also inhibited the cytotoxic effect of RV. The mechanism of zinc was related at least in part to the activation of MAPK activity, but also a direct antiviral effect was observed. Racecadotril showed a potent and selective inhibition of active secretion, being particularly effective in the first phase of RV diarrhea. The use of drugs active at the colonic level, therefore, offers effective options to treat intestinal infections in childhood. In addition, the colon is the natural site of colonic microflora, a target of probiotic therapy, which is the first line of approach recommended by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition to treat infectious diarrhea.

  20. The Relevance of the Colon to Zinc Nutrition

    Directory of Open Access Journals (Sweden)

    Geetha Lavaniya Gopalsamy

    2015-01-01

    Full Text Available Globally, zinc deficiency is widespread, despite decades of research highlighting its negative effects on health, and in particular upon child health in low-income countries. Apart from inadequate dietary intake of bioavailable zinc, other significant contributors to zinc deficiency include the excessive intestinal loss of endogenously secreted zinc and impairment in small intestinal absorptive function. Such changes are likely to occur in children suffering from environmental (or tropical enteropathy (EE—an almost universal condition among inhabitants of developing countries characterized by morphologic and functional changes in the small intestine. Changes to the proximal gut in environmental enteropathy will likely influence the nature and amount of zinc delivered into the large intestine. Consequently, we reviewed the current literature to determine if colonic absorption of endogenous or exogenous (dietary zinc could contribute to overall zinc nutriture. Whilst we found evidence that significant zinc absorption occurs in the rodent colon, and is favoured when microbially-fermentable carbohydrates (specifically resistant starch are consumed, it is unclear whether this process occur in humans and/or to what degree. Constraints in study design in the few available studies may well have masked a possible colonic contribution to zinc nutrition. Furthermore these few available human studies have failed to include the actual target population that would benefit, namely infants affected by EE where zinc delivery to the colon may be increased and who are also at risk of zinc deficiency. In conducting this review we have not been able to confirm a colonic contribution to zinc absorption in humans. However, given the observations in rodents and that feeding resistant starch to children is feasible, definitive studies utilising the dual stable isotope method in children with EE should be undertaken.

  1. White and dark kidney beans reduce colonic mucosal damage and inflammation in response to dextran sodium sulfate.

    Science.gov (United States)

    Monk, Jennifer M; Zhang, Claire P; Wu, Wenqing; Zarepoor, Leila; Lu, Jenifer T; Liu, Ronghua; Pauls, K Peter; Wood, Geoffrey A; Tsao, Rong; Robinson, Lindsay E; Power, Krista A

    2015-07-01

    Common beans are a rich source of nondigestible fermentable components and phenolic compounds that have anti-inflammatory effects. We assessed the gut-health-promoting potential of kidney beans in healthy mice and their ability to attenuate colonic inflammation following dextran sodium sulphate (DSS) exposure (via drinking water, 2% DSS w/v, 7 days). C57BL/6 mice were fed one of three isocaloric diets: basal diet control (BD), or BD supplemented with 20% cooked white (WK) or dark red kidney (DK) bean flour for 3 weeks. In healthy mice, anti-inflammatory microbial-derived cecal short chain fatty acid (SCFA) levels (acetate, butyrate and propionate), colon crypt height and colonic Mucin 1 (MUC1) and Resistin-like Molecule beta (Relmβ) mRNA expression all increased in WK- and DK-fed mice compared to BD, indicative of enhanced microbial activity, gut barrier integrity and antimicrobial defense response. During colitis, both bean diets reduced (a) disease severity, (b) colonic histological damage and (c) increased mRNA expression of antimicrobial and barrier integrity-promoting genes (Toll-like Receptor 4 (TLR4), MUC1-3, Relmβ and Trefoil Factor 3 (TFF3)) and reduced proinflammatory mediator expression [interleukin (IL)-1β, IL-6, interferon (IFN)γ, tumor necrosis factor (TNF)α and monocyte chemoattractant protein-1], which correlated with reduced colon tissue protein levels. Further, bean diets exerted a systemic anti-inflammatory effect during colitis by reducing serum levels of IL-17A, IFNγ, TNFα, IL-1β and IL-6. In conclusion, both WK and DK bean-supplemented diets enhanced microbial-derived SCFA metabolite production, gut barrier integrity and the microbial defensive response in the healthy colon, which supported an anti-inflammatory phenotype during colitis. Collectively, these data demonstrate a beneficial colon-function priming effect of bean consumption that mitigates colitis severity. Crown Copyright © 2015. Published by Elsevier Inc. All rights

  2. Colonic diverticulosis is not a risk factor for colonic adenoma.

    Science.gov (United States)

    Hong, Wandong; Dong, Lemei; Zippi, Maddalena; Stock, Simon; Geng, Wujun; Xu, Chunfang; Zhou, Mengtao

    2018-01-01

    Colonic diverticulosis may represent a risk factor for colonic adenomas by virtue of the fact that evolving data suggest that these 2 conditions may share common risk factors such as Western dietary pattern and physical inactivity. This study aims to investigate the association between colonic diverticulosis and colonic adenomas in mainland China. We conducted a cross-sectional study on patients who underwent colonoscopic examination between October 2013 and December 2014 in a university hospital in mainland China. Age, gender, colonic adenomas, advanced adenomas, and distribution of diverticulosis were recorded during the procedures. Multivariate logistic regression and stratified analysis were used to evaluate the associations between the prevalence of diverticulosis and age, sex, and presence of colonic adenomas and advanced adenomas. A total of 17,456 subjects were enrolled. The prevalence of colonic diverticulosis and adenoma was 2.4% and 13.2%, respectively. With regard to distribution of diverticula, most (365/424, 86.1%) were right-sided. Multiple logistic regression analysis suggested that age and male gender were independent risk factors for adenoma and advanced adenoma. There was no relationship between diverticulosis or location of diverticulosis and presence of adenoma and advanced adenoma adjusting by age and gender. In a stratified analysis according to age and gender, similar results were also noted. There was no statistical relationship between diverticulosis and the risk of adenoma and advanced adenoma. Our results may not be generalized to the Western population due to the fact that left-sided diverticular cases were very small in our study.

  3. Navy and black bean supplementation primes the colonic mucosal microenvironment to improve gut health.

    Science.gov (United States)

    Monk, Jennifer M; Lepp, Dion; Wu, Wenqing; Pauls, K Peter; Robinson, Lindsay E; Power, Krista A

    2017-11-01

    Common beans (Phaseolus vulgaris L.) are enriched in non-digestible fermentable carbohydrates and phenolic compounds that can modulate the colonic microenvironment (microbiota and host epithelial barrier) to improve gut health. In a comprehensive assessment of the impact of two commonly consumed bean varieties (differing in levels and types of phenolic compounds) within the colonic microenvironment, C57Bl/6 mice were fed diets supplemented with 20% cooked navy bean (NB) or black bean (BB) flours or an isocaloric basal diet control (BD) for 3 weeks. NB and BB similarly altered the fecal microbiota community structure (16S rRNA sequencing) notably by increasing the abundance of carbohydrate fermenting bacteria such as Prevotella, S24-7 and Ruminococcus flavefaciens, which coincided with enhanced short chain fatty acid (SCFA) production (microbial-derived carbohydrate fermentation products) and colonic expression of the SCFA receptors GPR-41/-43/-109a. Both NB and BB enhanced multiple aspects of mucus and epithelial barrier integrity vs. BD including: (i) goblet cell number, crypt mucus content and mucin mRNA expression, (ii) anti-microbial defenses (Reg3γ), (iii) crypt length and epithelial cell proliferation, (iv) apical junctional complex components (occludin, JAM-A, ZO-1 and E-cadherin) mRNA expression and (v) reduced serum endotoxin concentrations. Interestingly, biomarkers of colon barrier integrity (crypt height, mucus content, cell proliferation and goblet cell number) were enhanced in BB vs. NB-fed mice, suggesting added benefits attributable to unique BB components (e.g., phenolics). Overall, NB and BB improved baseline colonic microenvironment function by altering the microbial community structure and activity and promoting colon barrier integrity and function; effects which may prove beneficial in attenuating gut-associated diseases. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  4. Microbial syntrophy: interaction for the common good.

    Science.gov (United States)

    Morris, Brandon E L; Henneberger, Ruth; Huber, Harald; Moissl-Eichinger, Christine

    2013-05-01

    Classical definitions of syntrophy focus on a process, performed through metabolic interaction between dependent microbial partners, such as the degradation of complex organic compounds under anoxic conditions. However, examples from past and current scientific discoveries suggest that a new, simple but wider definition is necessary to cover all aspects of microbial syntrophy. We suggest the term 'obligately mutualistic metabolism', which still focuses on microbial metabolic cooperation but also includes an ecological aspect: the benefit for both partners. By the combined metabolic activity of microorganisms, endergonic reactions can become exergonic through the efficient removal of products and therefore enable a microbial community to survive with minimal energy resources. Here, we explain the principles of classical and non-classical syntrophy and illustrate the concepts with various examples. We present biochemical fundamentals that allow microorganism to survive under a range of environmental conditions and to drive important biogeochemical processes. Novel technologies have contributed to the understanding of syntrophic relationships in cultured and uncultured systems. Recent research highlights that obligately mutualistic metabolism is not limited to certain metabolic pathways nor to certain environments or microorganisms. This beneficial microbial interaction is not restricted to the transfer of reducing agents such as hydrogen or formate, but can also involve the exchange of organic, sulfurous- and nitrogenous compounds or the removal of toxic compounds. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  5. Impact of metal pollution and Thlaspi caerulescens growth on soil microbial communities

    NARCIS (Netherlands)

    Epelde, L.; Becerril, J.M.; Kowalchuk, G.A.; Deng, Y.; Zhou, J.N.; Garbisu, C.

    2010-01-01

    Soil microorganisms drive critical functions in plant-soil systems. As such, various microbial properties have been proposed as indicators of soil functioning, making them potentially useful in evaluating the recovery of polluted soils via phytoremediation strategies. To evaluate microbial responses

  6. Environmental Drivers of Differences in Microbial Community Structure in Crude Oil Reservoirs across a Methanogenic Gradient

    OpenAIRE

    Shelton, Jenna L.; Akob, Denise M.; McIntosh, Jennifer C.; Fierer, Noah; Spear, John R.; Warwick, Peter D.; McCray, John E.

    2016-01-01

    Stimulating in situ microbial communities in oil reservoirs to produce natural gas is a potentially viable strategy for recovering additional fossil fuel resources following traditional recovery operations. Little is known about what geochemical parameters drive microbial population dynamics in biodegraded, methanogenic oil reservoirs. We investigated if microbial community structure was significantly impacted by the extent of crude oil biodegradation, extent of biogenic methane production, a...

  7. Colonization and environment

    International Nuclear Information System (INIS)

    Garcia Gutierrez, E.

    1999-01-01

    The environmental results of the colonization, process and their consequences are analyzed in the local, national and international order, the activities through which the acts on the means and the nature of these. It is examined the meaning of the sustainable development, the phenomenon of the exhaustion of the ecosystems and their responsible ones. It discusses the importance of the Orinoquia in the mark of the environmental problems in the international order, the region has been intensely exploded by means of intensive production systems, what has led to the exhaustion of these areas in the world environment. The colonist's paper is exposed in the environmental deterioration, in front of the function of the tropical humid forest and it confirms a focus that it approaches the environmental problem from a perspective that makes emphasis in the social component of that problem, in opposition to the conservators where the ecosystem is the only valid reason and the social groups that intervene him, they should simply disappear. It is necessary the necessity to focus of integral way, the colonist's nature like element of a social group, the list that completes in the mark of the nation and their development model, the political economic system and the nationality inside which makes their economic decisions and of production. It is recognized that they are not enough solutions of technical order to impact on the use and sustainable handling of the Orinoquia, but rather it should be contemplated the economic, social, environmental and political aspects of the problem simultaneously, as well as the growing and resolved participation of the social group in their group

  8. Turbulent current drive mechanisms

    Science.gov (United States)

    McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

    2017-08-01

    Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

  9. Fast wave current drive

    International Nuclear Information System (INIS)

    Goree, J.; Ono, M.; Colestock, P.; Horton, R.; McNeill, D.; Park, H.

    1985-07-01

    Fast wave current drive is demonstrated in the Princeton ACT-I toroidal device. The fast Alfven wave, in the range of high ion-cyclotron harmonics, produced 40 A of current from 1 kW of rf power coupled into the plasma by fast wave loop antenna. This wave excites a steady current by damping on the energetic tail of the electron distribution function in the same way as lower-hybrid current drive, except that fast wave current drive is appropriate for higher plasma densities

  10. Identifying Method of Drunk Driving Based on Driving Behavior

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhao

    2011-05-01

    Full Text Available Drunk driving is one of the leading causes contributing to traffic crashes. There are numerous issues that need to be resolved with the current method of identifying drunk driving. Driving behavior, with the characteristic of real-time, was extensively researched to identify impaired driving behaviors. In this paper, the drives with BACs above 0.05% were defined as drunk driving state. A detailed comparison was made between normal driving and drunk driving. The experiment in driving simulator was designed to collect the driving performance data of the groups. According to the characteristics analysis for the effect of alcohol on driving performance, seven significant indicators were extracted and the drunk driving was identified by the Fisher Discriminant Method. The discriminant function demonstrated a high accuracy of classification. The optimal critical score to differentiate normal from drinking state was found to be 0. The evaluation result verifies the accuracy of classification method.

  11. Gut Microbial Diversity in Rat Model Induced by Rhubarb

    Science.gov (United States)

    Peng, Ying; Wu, Chunfu; Yang, Jingyu; Li, Xiaobo

    2014-01-01

    Rhubarb is often used to establish chronic diarrhea and spleen (Pi)-deficiency syndrome animal models in China. In this study, we utilized the enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) method to detect changes in bacterial diversity in feces and the bowel mucosa associated with this model. Total microbial genomic DNA from the small bowel (duodenum, jejunum, and ileum), large bowel (proximal colon, distal colon, and rectum), cecum, and feces of normal and rhubarb-exposed rats were used as templates for the ERIC-PCR analysis. We found that the fecal microbial composition did not correspond to the bowel bacteria mix. More bacterial diversity was observed in the ileum of rhubarb-exposed rats (Panalysis with the SPSS software, the Canonical Discriminant Function Formulae for model rats was established. PMID:25048267

  12. Mangrove microbial diversity and the impact of trophic contamination.

    Science.gov (United States)

    Bouchez, Agnès; Pascault, Noémie; Chardon, Cècile; Bouvy, Marc; Cecchi, Philippe; Lambs, Luc; Herteman, Mélanie; Fromard, François; Got, Patrice; Leboulanger, Christophe

    2013-01-15

    Mangroves are threatened ecosystems that provide numerous ecosystem services, especially through their wide biodiversity, and their bioremediation capacity is a challenging question in tropical areas. In a mangrove in Mayotte, we studied the potential role of microbial biofilm communities in removing nutrient loads from pre-treated wastewater. Microbial community samples were collected from tree roots, sediments, water, and from a colonization device, and their structure and dynamics were compared in two areas: one exposed to sewage and the other not. The samples from the colonization devices accurately reflected the natural communities in terms of diversity. Communities in the zone exposed to sewage were characterized by more green algae and diatoms, higher bacteria densities, as well as different compositions. In the area exposed to sewage, the higher cell densities associated with specific diversity patterns highlighted adapted communities that may play a significant role in the fate of nutrients. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. A highly diverse, desert-like microbial biocenosis on solar panels in a Mediterranean city.

    Science.gov (United States)

    Dorado-Morales, Pedro; Vilanova, Cristina; Peretó, Juli; Codoñer, Francisco M; Ramón, Daniel; Porcar, Manuel

    2016-07-05

    Microorganisms colonize a wide range of natural and artificial environments although there are hardly any data on the microbial ecology of one the most widespread man-made extreme structures: solar panels. Here we show that solar panels in a Mediterranean city (Valencia, Spain) harbor a highly diverse microbial community with more than 500 different species per panel, most of which belong to drought-, heat- and radiation-adapted bacterial genera, and sun-irradiation adapted epiphytic fungi. The taxonomic and functional profiles of this microbial community and the characterization of selected culturable bacteria reveal the existence of a diverse mesophilic microbial community on the panels' surface. This biocenosis proved to be more similar to the ones inhabiting deserts than to any human or urban microbial ecosystem. This unique microbial community shows different day/night proteomic profiles; it is dominated by reddish pigment- and sphingolipid-producers, and is adapted to withstand circadian cycles of high temperatures, desiccation and solar radiation.

  14. Particle-associated flagellates: swimming patterns, colonization rates, and grazing on attached bacteria

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Grossart, H.P.; Ploug, H.

    2004-01-01

    Some pelagic flagellates colonize particles, such as marine snow, where they graze on bacteria and thus impact the dynamics of the attached microbial communities. Particle colonization is governed by motility. Swimming patterns of 2 particle-associated flagellates, Bodo designis and Spumella sp......., are very different, the former swimming slowly in an erratic, random pattern, and the latter faster and along smooth helixes of variable amplitude and frequency. At spatial scales exceeding ca. 50 mum, the motility of B. designis can be described as a random walk and modeled as diffusion. Spumella sp...

  15. Effects of treatment with antimicrobial agents on the human colonic microflora

    Directory of Open Access Journals (Sweden)

    Fatemeh Rafii

    2008-12-01

    Full Text Available Fatemeh Rafii, John B Sutherland, Carl E CernigliaDivision of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR, USAAbstract: Antimicrobial agents are the most valuable means available for treating bacterial infections. However, the administration of therapeutic doses of antimicrobial agents to patients is a leading cause of disturbance of the normal gastrointestinal microflora. This disturbance results in diminishing the natural defense mechanisms provided by the colonic microbial ecosystem, making the host vulnerable to infection by commensal microorganisms or nosocomial pathogens. In this minireview, the impacts of antimicrobials, individually and in combinations, on the human colonic microflora are discussed.Keywords: antibiotics, intestinal bacteria

  16. The role of bifidobacteria in newborn health and the intestinal microbial balance

    OpenAIRE

    Mazzola, Giuseppe

    2015-01-01

    Gut microbial acquisition during the early stage of life is an extremely important event since it affects the health status of the host. In this contest the healthy properties of the genus Bifidobacterium have a central function in newborns. The aim of this thesis was to explore the dynamics of the gut microbial colonization in newborns and to suggest possible strategies to maintain or restore a correct balance of gut bacterial population in inf...

  17. Linear step drive

    International Nuclear Information System (INIS)

    Haniger, L.; Elger, R.; Kocandrle, L.; Zdebor, J.

    1986-01-01

    A linear step drive is described developed in Czechoslovak-Soviet cooperation and intended for driving WWER-1000 control rods. The functional principle is explained of the motor and the mechanical and electrical parts of the drive, power control, and the indicator of position are described. The motor has latches situated in the reactor at a distance of 3 m from magnetic armatures, it has a low structural height above the reactor cover, which suggests its suitability for seismic localities. Its magnetic circuits use counterpoles; the mechanical shocks at the completion of each step are damped using special design features. The position indicator is of a special design and evaluates motor position within ±1% of total travel. A drive diagram and the flow chart of both the control electronics and the position indicator are presented. (author) 4 figs

  18. Fundamentals of electrical drives

    NARCIS (Netherlands)

    Veltman, A.; Pulle, D.W.J.; de Doncker, R.W.

    2016-01-01

    Comprehensive, user-friendly, color illustrated introductory text for electrical drive systems that simplifies the understanding of electrical machine principles Updated edition covers innovations in machine design, power semi-conductors, digital signal processors and simulation software Presents

  19. Science of driving.

    Science.gov (United States)

    2016-08-01

    The Science of Driving project focused on developing a collaborative relationship to develop curriculum units for middle school and high school students to engage them in exciting real-world scenarios. This effort involved faculty, staff, and student...

  20. Drugs and driving

    NARCIS (Netherlands)

    Walsh, J. Michael; De Gier, Johan J.; Christopherson, Asbjørg S.; Verstraete, Alain G.

    The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence-which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for

  1. Gut microbiota utilize immunoglobulin A for mucosal colonization.

    Science.gov (United States)

    Donaldson, G P; Ladinsky, M S; Yu, K B; Sanders, J G; Yoo, B B; Chou, W-C; Conner, M E; Earl, A M; Knight, R; Bjorkman, P J; Mazmanian, S K

    2018-05-18

    The immune system responds vigorously to microbial infection while permitting lifelong colonization by the microbiome. Mechanisms that facilitate the establishment and stability of the gut microbiota remain poorly described. We found that a regulatory system in the prominent human commensal Bacteroides fragilis modulates its surface architecture to invite binding of immunoglobulin A (IgA) in mice. Specific immune recognition facilitated bacterial adherence to cultured intestinal epithelial cells and intimate association with the gut mucosal surface in vivo. The IgA response was required for B. fragilis (and other commensal species) to occupy a defined mucosal niche that mediates stable colonization of the gut through exclusion of exogenous competitors. Therefore, in addition to its role in pathogen clearance, we propose that IgA responses can be co-opted by the microbiome to engender robust host-microbial symbiosis. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  2. The Colonic Microbiome and Epithelial Transcriptome Are Altered in Rats Fed a High-Protein Diet Compared with a Normal-Protein Diet.

    Science.gov (United States)

    Mu, Chunlong; Yang, Yuxiang; Luo, Zhen; Guan, Leluo; Zhu, Weiyun

    2016-03-01

    A high-protein diet (HPD) can produce hazardous compounds and reduce butyrate-producing bacteria in feces, which may be detrimental to gut health. However, information on whether HPD affects intestinal function is limited. The aim of this study was to determine the impact of an HPD on the microbiota, microbial metabolites, and epithelial transcriptome in the colons of rats. Adult male Wistar rats were fed either a normal-protein diet (20% protein, 56% carbohydrate) or an HPD (45% protein, 30% carbohydrate) for 6 wk (n = 10 rats per group, individually fed). After 6 wk, the colonic microbiome, microbial metabolites, and epithelial transcriptome were determined. Compared with the normal-protein diet, the HPD adversely altered the colonic microbiota by increasing (P 0.7, P < 0.05) with genes and metabolites generally regarded as being involved in disease pathogenesis, suggesting these bacteria may mediate the detrimental effects of HPDs on colonic health. Our findings suggest that the HPD altered the colonic microbial community, shifted the metabolic profile, and affected the host response in the colons of rats toward an increased risk of colonic disease. © 2016 American Society for Nutrition.

  3. Instant Google Drive starter

    CERN Document Server

    Procopio, Mike

    2013-01-01

    This book is a Starter which teaches you how to use Google Drive practically. This book is perfect for people of all skill levels who want to enjoy the benefits of using Google Drive to safely store their files online and in the cloud. It's also great for anyone looking to learn more about cloud computing in general. Readers are expected to have an Internet connection and basic knowledge of using the internet.

  4. Control rod driving mechanism

    International Nuclear Information System (INIS)

    Ooshima, Yoshio.

    1983-01-01

    Purpose: To perform reliable scram operation, even if abnormality should occur in a system instructing scram operation in FBR type reactors. Constitution: An aluminum alloy member to be melt at a predetermined temperature (about 600sup(o)C) is disposed to a connection part between a control rod and a driving mechanism, whereby the control rod is detached from the driving mechanism and gravitationally fallen to the reactor core. (Ikeda, J.)

  5. Modulated Current Drive Measurements

    International Nuclear Information System (INIS)

    Petty, C.C.; Lohr, J.; Luce, T.C.; Prater, R.; Cox, W.A.; Forest, C.B.; Jayakumar, R.J.; Makowski, M.A.

    2005-01-01

    A new measurement approach is presented which directly determines the noninductive current profile from the periodic response of the motional Stark effect (MSE) signals to the slow modulation of the external current drive source. A Fourier transform of the poloidal magnetic flux diffusion equation is used to analyze the MSE data. An example of this measurement technique is shown using modulated electron cyclotron current drive (ECCD) discharges from the DIII-D tokamak

  6. Belt drive construction improvement

    Directory of Open Access Journals (Sweden)

    I.Yu. Khomenko

    2012-08-01

    Full Text Available The possibility of the traction capacity increase of the belt drive TRK is examined. This was done for the purpose of air conditioning system of passenger car with double-generator system energy supplying. Belts XPC (made by the German firm «Continental ContiTech» testing were conducted. The results confirmed the possibility of their usage in order to improve belt drive TRK characteristics.

  7. Self-driving carsickness.

    Science.gov (United States)

    Diels, Cyriel; Bos, Jelte E

    2016-03-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and productivity. However, we here show that the envisaged scenarios all lead to an increased risk of motion sickness. As such, the benefits this technology is assumed to bring may not be capitalised on, in particular by those already susceptible to motion sickness. This can negatively affect user acceptance and uptake and, in turn, limit the potential socioeconomic benefits that this emerging technology may provide. Following a discussion on the causes of motion sickness in the context of self-driving cars, we present guidelines to steer the design and development of automated vehicle technologies. The aim is to limit or avoid the impact of motion sickness and ultimately promote the uptake of self-driving cars. Attention is also given to less well known consequences of motion sickness, in particular negative aftereffects such as postural instability, and detrimental effects on task performance and how this may impact the use and design of self-driving cars. We conclude that basic perceptual mechanisms need to be considered in the design process whereby self-driving cars cannot simply be thought of as living rooms, offices, or entertainment venues on wheels. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  8. Dementia and driving.

    Science.gov (United States)

    O'Neill, D; Neubauer, K; Boyle, M; Gerrard, J; Surmon, D; Wilcock, G K

    1992-04-01

    Many European countries test cars, but not their drivers, as they age. There is evidence to suggest that human factors are more important than vehicular factors as causes of motor crashes. The elderly also are involved in more accidents per distance travelled than middle-aged drivers. As the UK relies on self-certification of health by drivers over the age of 70 years, we examined the driving practices of patients with dementia attending a Memory Clinic. Nearly one-fifth of 329 patients with documented dementia continued to drive after the onset of dementia, and impaired driving ability was noted in two-thirds of these. Their families experienced great difficulty in persuading patients to stop driving, and had to invoke outside help in many cases. Neuropsychological tests did not help to identify those who drove badly while activity of daily living scores were related to driving ability. These findings suggest that many patients with dementia drive in an unsafe fashion after the onset of the illness. The present system of self-certification of health by the elderly for driver-licensing purposes needs to be reassessed.

  9. Enfermedad Diverticular del Colon

    Directory of Open Access Journals (Sweden)

    Gonzalo López Escobar

    1991-06-01

    Full Text Available

    Los divertículos del colon han sido reconocidos por varios observadores desde hace más de un siglo, pero en su mayor parte se trataba de casos aislados, hoy se la considera como la enfermedad del siglo XX, la de la era moderna y de los países industrializados y de avanzada tecnología (5,18,33.

    Según el diccionario de la Real Academia Española (11, divertículo, del latín, diverticulum, quiere decir desviación de un camino; y desde el punto de vista anatómico, apéndice hueco y terminado en fondo de saco. (Gráfica No. 1.

    Goligher (17 lo define como la “posada al borde del camino, probablemente un lugar, a menudo, de mala reputación”.

    Historia

    Según Hackford (18, el proceso fué descrito brevemente por Littre a comienzos del siglo XVIII; pero se le atribuye a Cruveilhier la primera descripción como proceso patológico en 1849, quien, además, mencionó: “encontramos, no rara vez, en el sigmoide, entre las bandas de fibras musculares longitudinales, una serie de pequeños tumores piriformes oscuros, que están formados por hernias de la mucosa a través de brechas en la capa muscular” (17.

    Fleischman en 1815 hizo la primera observación de la enfermedad y empleó el término divertículo (45.

    Rokitansky en 1.849, habló de una enfermedad adquirida y consideró que su causa consistía en la constipación (45.

    Virchowen 1853 describió la perisigmoiditis (45.

    En 1859 Sidney Jones informó de una fístula colo-vesical debida a diverticulitis (5,45.

    Loomis en 1870 describe una peritonitis como resultante de una diverticulitis (45.

    En 1877 Ball describió la anatomía patológica de la enfermedad y presentó dos casos de fístula colovesical debidas a diverticulitis (9. Cripps en 1.888 popularizó la colostomía de desviación como tratamiento para la fístula colovesical(18...

  10. Percutaneous drainage of colonic diverticular abscess: is colon resection necessary?

    Science.gov (United States)

    Gaertner, Wolfgang B; Willis, David J; Madoff, Robert D; Rothenberger, David A; Kwaan, Mary R; Belzer, George E; Melton, Genevieve B

    2013-05-01

    Recurrent diverticulitis has been reported in up to 30% to 40% of patients who recover from an episode of colonic diverticular abscess, so elective interval resection is traditionally recommended. The aim of this study was to review the outcomes of patients who underwent percutaneous drainage of colonic diverticular abscess without subsequent operative intervention. This was an observational study. This investigation was conducted at a tertiary care academic medical center and a single-hospital health system. Patients treated for symptomatic colonic diverticular abscess from 2002 through 2007 were included. The primary outcomes measured were complications, recurrence, and colectomy-free survival. Two hundred eighteen patients underwent percutaneous drainage of colonic diverticular abscesses. Thirty-two patients (15%) did not undergo subsequent colonic resection. Abscess location was pelvic (n = 9) and paracolic (n = 23), the mean abscess size was 4.2 cm, and the median duration of percutaneous drainage was 20 days. The comorbidities of this group of patients included severe cardiac disease (n = 16), immunodeficiency (n = 7), and severe pulmonary disease (n = 6). Freedom from recurrence at 7.4 years was 0.58 (95% CI 0.42-0.73). All recurrences were managed nonoperatively. Recurrence was significantly associated with an abscess size larger than 5 cm. Colectomy-free survival at 7.4 years was 0.17 (95% CI 0.13-0.21). This study was limited by its retrospective, nonexperimental design and short follow-up. In selected patients, observation after percutaneous drainage of colonic diverticular abscess appears to be a safe and low-risk management option.

  11. Complete colonic duplication in children.

    Science.gov (United States)

    Khaleghnejad Tabari, Ahmad; Mirshemirani, Alireza; Khaleghnejad Tabari, Nasibeh

    2012-01-01

    Complete colonic duplication is a very rare congenital anomaly that may have different presentations according to its location and size. Complete colonic duplication can occur in 15% of gastrointestinal duplication. We report two cases of complete colonic duplications, and their characteristics. We present two patients with complete colonic duplication with different types and presentations. Case 1: A 2- year old boy presented to the clinic with abdominal protrusion, difficulty to defecate, chronic constipation and mucosal prolaps covered bulging (rectocele) since he was 6 months old. The patient had palpable pelvic mass with doughy consistency. Rectal exam confirmed perirectal mass with soft consistency. The patient underwent a surgical operation that had total tubular colorectal duplication with one blind end and was treated with simple fenestration of distal end, and was discharged without complication. After two years follow up, he had normal defecation and good weight gain. Case 2: A 2 -day old infant was referred with imperforate anus and complete duplication of recto-sigmoid colon, diphallus, double bladder, and hypospadiasis. After clinical and paraclinical investigations, he underwent operations in several stages in different periods, and was discharged without complications. After four years follow up, he led a normal life. The patients with complete duplication have to be examined carefully because of the high incidence of other systemic anomalies. Treatment includes simple resection of distal common wall, fenestration, and repair other associated anomalies.

  12. Colonic infusions of short-chain fatty acid mixtures promote energy metabolism in overweight/obese men

    DEFF Research Database (Denmark)

    Canfora, Emanuel E; van der Beek, Christina M; Jocken, Johan W E

    2017-01-01

    Short-chain fatty acids (SCFA), formed by microbial fermentation, are believed to be involved in the aetiology of obesity and diabetes. This study investigated the effects of colonic administration of physiologically relevant SCFA mixtures on human substrate and energy metabolism...

  13. Ecosystem and physiological scales of microbial responses to nutrients in a detritus-based stream: results of a 5-year continuous enrichment

    Science.gov (United States)

    Keller Suberkropp; Vladislav Gulis; Amy D. Rosemond; Jonathan Benstead

    2010-01-01

    Our study examined the response of leaf detritus–associated microorganisms (both bacteria and fungi) to a 5-yr continuous nutrient enrichment of a forested headwater stream. Leaf litter dominates detritus inputs to such streams and, on a system wide scale, serves as the key substrate for microbial colonization. We determined physiological responses as microbial biomass...

  14. Microbial interactions: ecology in a molecular perspective.

    Science.gov (United States)

    Braga, Raíssa Mesquita; Dourado, Manuella Nóbrega; Araújo, Welington Luiz

    2016-12-01

    The microorganism-microorganism or microorganism-host interactions are the key strategy to colonize and establish in a variety of different environments. These interactions involve all ecological aspects, including physiochemical changes, metabolite exchange, metabolite conversion, signaling, chemotaxis and genetic exchange resulting in genotype selection. In addition, the establishment in the environment depends on the species diversity, since high functional redundancy in the microbial community increases the competitive ability of the community, decreasing the possibility of an invader to establish in this environment. Therefore, these associations are the result of a co-evolution process that leads to the adaptation and specialization, allowing the occupation of different niches, by reducing biotic and abiotic stress or exchanging growth factors and signaling. Microbial interactions occur by the transference of molecular and genetic information, and many mechanisms can be involved in this exchange, such as secondary metabolites, siderophores, quorum sensing system, biofilm formation, and cellular transduction signaling, among others. The ultimate unit of interaction is the gene expression of each organism in response to an environmental (biotic or abiotic) stimulus, which is responsible for the production of molecules involved in these interactions. Therefore, in the present review, we focused on some molecular mechanisms involved in the microbial interaction, not only in microbial-host interaction, which has been exploited by other reviews, but also in the molecular strategy used by different microorganisms in the environment that can modulate the establishment and structuration of the microbial community. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  15. Microbial electrosynthetic cells

    Energy Technology Data Exchange (ETDEWEB)

    May, Harold D.; Marshall, Christopher W.; Labelle, Edward V.

    2018-01-30

    Methods are provided for microbial electrosynthesis of H.sub.2 and organic compounds such as methane and acetate. Method of producing mature electrosynthetic microbial populations by continuous culture is also provided. Microbial populations produced in accordance with the embodiments as shown to efficiently synthesize H.sub.2, methane and acetate in the presence of CO.sub.2 and a voltage potential. The production of biodegradable and renewable plastics from electricity and carbon dioxide is also disclosed.

  16. Control rod drive

    International Nuclear Information System (INIS)

    Hawke, B.C.

    1986-01-01

    A reactor core, one or more control rods, and a control rod drive are described for selectively inserting and withdrawing the one or more control rods into and from the reactor core, which consists of: a support structure secured beneath the reactor core; control rod positioning means supported by the support structure for movably supporting the control rod for movement between a lower position wherein the control rod is located substantially beneath the reactor core and an upper position wherein at least an upper portion of the control rod extends into the reactor core; transmission means; primary drive means connected with the control rod positioning means by the transmission means for positioning the control rod under normal operating conditions; emergency drive means for moving the control rod from the lower position to the upper position under emergency conditions, the emergency drive means including a weight movable between an upper and a lower position, means for movably supporting the weight, and means for transmitting gravitational force exerted on the weight to the control rod positioning means to move the control rod upwardly when the weight is pulled downwardly by gravity; the transmission means connecting the control rod positioning means with the emergency drive means so that the primary drive means effects movement of the weight and the control rod in opposite directions under normal conditions, thus providing counterbalancing to reduce the force required for upward movement of the control rod under normal conditions; and restraint means for restraining the fall of the weight under normal operating conditions and disengaging the primary drive means to release the weight under emergency conditions

  17. The Economics of Colon Cancer.

    Science.gov (United States)

    Orangio, Guy R

    2018-04-01

    The economic burden of cancer on the national health expenditure is billions of dollars. The economic cost is measured on direct and indirect medical costs, which vary depending on stage at diagnosis, patient age, type of medical services, and site of service. Costs vary by region, physician behavior, and patient preferences. When analyzing the economic burden of survivors of colon cancer, we cannot forget the societal burden. Post-acute care and readmissions are major economic burdens. People with colon cancer have to be followed for their lifetime. Economic models are being studied to give cost-effective solutions to this problem. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Neurological manifestation of colonic adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Uzair Chaudhary

    2012-04-01

    Full Text Available Paraneoplastic neurologic disorders are extremely rare in cancer patients and are most commonly associated with certain tumors, such as ovarian cancer, small cell lung cancer, and breast cancer. We report here a paraneoplastic neurological syndrome in a 53-year-old man with colonic adenocarcinoma with a solitary liver metastasis. His paraneoplastic syndrome was successfully treated by methylprednisolone and primary oncologic therapies including neoadjuvant chemotherapy and definitive surgery. This is also the first documented case of simultaneous manifestation of a sensory neuropathy and limbic encephalitis with colon cancer.

  19. Control rod drives

    International Nuclear Information System (INIS)

    Hayakawa, Hiroyasu.

    1979-01-01

    Purpose: To enable rapid control in a simple circuit by providing a motor control device having an electric capacity capable of simultaneously driving all of the control rods rapidly only in the inserting direction as well as a motor controlling device capable of fine control for the insertion and extraction at usual operation. Constitution: The control rod drives comprise a first motor control device capable of finely controlling the control rods both in inserting and extracting directions, a second motor control device capable of rapidly driving the control rods only in the inserting direction, and a first motor switching circuit and a second motor switching circuit switched by switches. Upon issue of a rapid insertion instruction for the control rods, the second motor switching circuit is closed by the switch and the second motor control circuit and driving motors are connected. Thus, each of the control rod driving motors is driven at a high speed in the inserting direction to rapidly insert all of the control rods. (Yoshino, Y.)

  20. Epilepsy and driving

    Directory of Open Access Journals (Sweden)

    Matej Mavrič

    2015-05-01

    Full Text Available Epilepsy poses a risk for all participants in road traffic; therefore people with epilepsy do not meet the criteria for an unlimited driving license. Their driving is affected not only by epileptic seizures causing impaired consciousness and involuntary movements, but also by antiepileptic drugs with their many unwanted affects. The experts have not yet agreed on whether people with epilepsy have an increased risk of experiencing a road traffic accident. However, recent data suggests that the overall risk is lower compared to other medical conditions. Scientific evidence forms the basis of legislation, which by limiting people with epilepsy, enables all participants in road traffic to drive in the safest possible environment. The legislation that governs epilepsy and driving in Slovenia has been recently thoroughly reformed and thus allows a less discriminatory management of people with epilepsy. Although people with epilepsy experience many issues in their daily life, including their personal relationships and employment, they often list the need for driving as a top concern in surveys. General physicians play an important role in managing the issues of people with epilepsy.

  1. Self-rated Driving and Driving Safety in Older Adults

    OpenAIRE

    Ross, Lesley A.; Dodson, Joan; Edwards, Jerri D.; Ackerman, Michelle L.; Ball, Karlene

    2012-01-01

    Many U.S. states rely on older adults to self-regulate their driving and determine when driving is no longer a safe option. However, the relationship of older adults’ self-rated driving in terms of actual driving competency outcomes is unclear. The current study investigates self-rated driving in terms of (1) systematic differences between older adults with high (good/excellent) versus low (poor/fair/average) self-ratings, and (2) the predictive nature of self-rated driving to adverse driving...

  2. MALToma of the Transverse colon, Ascending colon and Caecum: A ...

    African Journals Online (AJOL)

    Background The stomach is the most common site formucosa - associated lymphoid tissue [MALT] lymphoma (MALToma). MALToma of the colon is a rare occurrence. It is on this background that we report this case. Methods The case records a patient with a MALT lymphoma and a review of the literature on the subject ...

  3. Bioreceptivity of dolostones to fungal colonization

    Directory of Open Access Journals (Sweden)

    Ascaso, C.

    2008-06-01

    Full Text Available In many historic monuments in which signs of biodeterioration have been frequently reported, dolostones were used as dimension stone for their construction. In an effort to assess the influence of the texture of dolostones on their potential bioreceptivity, we characterized microbial colonization strategies in dolostone samples of predictably different textural features by scanning electron microscopy in back scattered electron mode (SEM-BSE, low temperature scanning electron microscopy (LTSEM, transmission light microscopy (TLM and mercury intrusion porosimetry (MIP. Fungi were the predominant microorganisms in the dolostones examined and their colonization showed three well defined stages with the final consequence of complete rock disaggregation. The results of this study indicate that porosity differences (mainly the extent and type were particularly relevant for determining the presence and extent of each colonization stage. As a determinant of bioreceptivity, the porosity of dolostones will also condition the decay processes associated with this colonization. These findings highlight the fact that the intrinsic properties of dolostones, such as texture, need to be considered when selecting this type of stone for future construction projects.La dolomía ha sido empleada como piedra de fábrica en la construcción de muchos monumentos históricos en los que se han detectado fenómenos de biodeterioro en numerosas ocasiones. En este trabajo se evalúa cómo influye la textura de las dolomías en las estrategias adoptadas por los microorganismos para colonizar estos materiales pétreos. Para ello se han caracterizado muestras de dolomías con diferentes texturas mediante microscopía electrónica de barrido en modo de electrones retrodispersados (SEM-BSE, microscopía electrónica de barrido a bajas temperaturas (LTSEM, microscopía de luz transmitida (TLM y porosimetría por intrusión de mercurio (MIP. De estas observaciones se deduce que

  4. Effect of Gamma radiation on microbial population of natural casings

    International Nuclear Information System (INIS)

    Trigo, M.J.; Fraqueza, M.J.

    1998-01-01

    The high microbial load of fresh and dry natural casings increases the risk of meat product contamination with pathogenic microorganims, agents of foodborn diseases. The aim of this work is to evaluate the killing effect of gamma radiation on the resident microbial population of pork and beef casings, to improve their hygiene and safety. Portions of fresh pork (small intestine and colon) and dry beef casings were irradiated in a Cobalt 60 source with absorbed doses of 1, 2, 5 and 10 kGy. The D 10 values of total aerobic microorganisms in the pork casings were 1.65 kGy for colon and 1.54 kGy for small intestine. The D 10 value found in beef dry casings (small intestine) was 10.17 kGy. Radurization with 5 kGy was able to reduce, at least, 6 logs the coliform bacteria in pork casings. The killing effect over faecal Streptococci was 4 logs for pork fresh casings and 2 logs for beef dry casings. Gamma radiation with 5 kGy proved to be a convenient method to reduce substantially the microbial population of pork fresh casings. Otherwise, the microbial population of beef dry casings still resisted to 10 kGy

  5. Microbial biofilm formation and its consequences for the CELSS program

    Science.gov (United States)

    Mitchell, R.

    1994-01-01

    A major goal of the Controlled Ecology Life Support System (CELSS) program is to provide reliable and efficient life support systems for long-duration space flights. A principal focus of the program is on the growth of higher plants in growth chambers. These crops should be grown without the risk of damage from microbial contamination. While it is unlikely that plant pathogens will pose a risk, there are serious hazards associated with microorganisms carried in the nutrient delivery systems and in the atmosphere of the growth chamber. Our experience in surface microbiology showed that colonization of surfaces with microorganisms is extremely rapid even when the inoculum is small. After initial colonization extensive biofilms accumulate on moist surfaces. These microbial films metabolize actively and slough off continuously to the air and water. During plant growth in the CELSS program, microbial biofilms have the potential to foul sensors and to plug nutrient delivery systems. In addition both metabolic products of microbial growth and degradation products of materials being considered for use as nutrient reservoirs and for delivery are likely sources of chemicals known to adversly affect plant growth.

  6. Ursodeoxycholic acid and lithocholic acid exert anti-inflammatory actions in the colon.

    Science.gov (United States)

    Ward, Joseph B J; Lajczak, Natalia K; Kelly, Orlaith B; O'Dwyer, Aoife M; Giddam, Ashwini K; Ní Gabhann, Joan; Franco, Placido; Tambuwala, Murtaza M; Jefferies, Caroline A; Keely, Simon; Roda, Aldo; Keely, Stephen J

    2017-06-01

    inflammation and suggest that microbial metabolism of UDCA is necessary for the full expression of its protective actions. NEW & NOTEWORTHY On the basis of its cytoprotective and anti-inflammatory actions, the secondary bile acid ursodeoxycholic acid (UDCA) has well-established uses in both traditional and Western medicine. We identify a new role for the primary metabolite of UDCA, lithocholic acid, as a potent inhibitor of intestinal inflammatory responses, and we present data to suggest that microbial metabolism of UDCA is necessary for the full expression of its protective effects against colonic inflammation. Copyright © 2017 the American Physiological Society.

  7. PREPARATION AND CHARACTERIZATION OF CHITOSAN TABLETS OF ACECLOFENAC FOR COLON TARGETED DRUG DELIVERY

    OpenAIRE

    UMA DEVI,THIRUGANESH, SURESH

    2013-01-01

    The present study objective was to develop novel colon specific drug delivery systems for aceclofenac using chitosan as a microbially degradable polymeric carrier and to coat the optimized batches with a pH dependent polymeric coating solution containing Eudragit L 100 and S 100 (1:4). Tablets containing four proportions of chitosan were prepared. The tablets were evaluated for physicochemical properties, drug content, dissolution, water uptake & erosion characteristics, in vitro drug rel...

  8. Mast cell degranulation by a hemolytic lipid toxin decreases GBS colonization and infection

    OpenAIRE

    Gendrin, Claire; Vornhagen, Jay; Ngo, Lisa; Whidbey, Christopher; Boldenow, Erica; Santana-Ufret, Veronica; Clauson, Morgan; Burnside, Kellie; Galloway, Dionne P.; Waldorf, Kristina Adams; Piliponsky, Adrian M.; Rajagopal, Lakshmi

    2015-01-01

    Ascending infection of microbes from the lower genital tract into the amniotic cavity increases the risk of preterm birth, stillbirth, and newborn infections. Host defenses that are critical for preventing ascending microbial infection are not completely understood. Group B Streptococcus (GBS) are Gram-positive bacteria that frequently colonize the lower genital tract of healthy women but cause severe infections during pregnancy, leading to preterm birth, stillbirth, or early-onset newborn in...

  9. Microbial community composition affects soil fungistasis.

    Science.gov (United States)

    de Boer, Wietse; Verheggen, Patrick; Klein Gunnewiek, Paulien J A; Kowalchuk, George A; van Veen, Johannes A

    2003-02-01

    Most soils inhibit fungal germination and growth to a certain extent, a phenomenon known as soil fungistasis. Previous observations have implicated microorganisms as the causal agents of fungistasis, with their action mediated either by available carbon limitation (nutrient deprivation hypothesis) or production of antifungal compounds (antibiosis hypothesis). To obtain evidence for either of these hypotheses, we measured soil respiration and microbial numbers (as indicators of nutrient stress) and bacterial community composition (as an indicator of potential differences in the composition of antifungal components) during the development of fungistasis. This was done for two fungistatic dune soils in which fungistasis was initially fully or partly relieved by partial sterilization treatment or nutrient addition. Fungistasis development was measured as restriction of the ability of the fungi Chaetomium globosum, Fusarium culmorum, Fusarium oxysporum, and Trichoderma harzianum to colonize soils. Fungistasis did not always reappear after soil treatments despite intense competition for carbon, suggesting that microbial community composition is important in the development of fungistasis. Both microbial community analysis and in vitro antagonism tests indicated that the presence of pseudomonads might be essential for the development of fungistasis. Overall, the results lend support to the antibiosis hypothesis.

  10. Gammarus-Microbial Interactions: A Review

    Directory of Open Access Journals (Sweden)

    Daniel Nelson

    2011-01-01

    Full Text Available Gammarus spp. are typically classified as shredders under the functional feeding group classification. In the wild and in the laboratory, Gammarus spp. will often shred leaves, breaking them down into finer organic matter fractions. However, leaf litter is a poor quality food source (i.e., high C : N and C : P ratios and very little leaf material is assimilated by shredders. In freshwater habitats leaf litter is colonized rapidly (within ∼1-2 weeks by aquatic fungi and bacteria, making the leaves more palatable and nutritious to consumers. Several studies have shown that Gammarus spp. show preference for conditioned leaves over nonconditioned leaves and certain fungal species to others. Furthermore, Gammarus spp. show increased survival and growth rates when fed conditioned leaves compared to non-conditioned leaves. Thus, Gammarus spp. appear to rely on the microbial biofilm associated with leaf detritus as a source of carbon and/or essential nutrients. Also, Gammarus spp. can have both positive and negative effects on the microbial communities on which they fed, making them an important component of the microbial loop in aquatic ecosystems.

  11. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium.

    Science.gov (United States)

    Teixeira, Catarina; Almeida, C Marisa R; Nunes da Silva, Marta; Bordalo, Adriano A; Mucha, Ana P

    2014-09-15

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  13. Toyota hybrid synergy drive

    Energy Technology Data Exchange (ETDEWEB)

    Gautschi, H.

    2008-07-01

    This presentation made at the Swiss 2008 research conference on traffic by Hannes Gautschi, director of service and training at the Toyota company in Switzerland, takes a look at Toyota's hybrid drive vehicles. The construction of the vehicles and their combined combustion engines and electric generators and drives is presented and the combined operation of these components is described. Braking and energy recovery are discussed. Figures on the performance, fuel consumption and CO{sub 2} output of the hybrid vehicles are compared with those of conventional vehicles.

  14. Evolving colon injury management: a review.

    Science.gov (United States)

    Greer, Lauren T; Gillern, Suzanne M; Vertrees, Amy E

    2013-02-01

    The colon is the second most commonly injured intra-abdominal organ in penetrating trauma. Management of traumatic colon injuries has evolved significantly over the past 200 years. Traumatic colon injuries can have a wide spectrum of severity, presentation, and management options. There is strong evidence that most non-destructive colon injuries can be successfully managed with primary repair or primary anastomosis. The management of destructive colon injuries remains controversial with most favoring resection with primary anastomosis and others favor colonic diversion in specific circumstances. The historical management of traumatic colon injuries, common mechanisms of injury, demographics, presentation, assessment, diagnosis, management, and complications of traumatic colon injuries both in civilian and military practice are reviewed. The damage control revolution has added another layer of complexity to management with continued controversy.

  15. Colon Trauma: Evidence-Based Practices.

    Science.gov (United States)

    Yamamoto, Ryo; Logue, Alicia J; Muir, Mark T

    2018-01-01

    Colon injury is not uncommon and occurs in about a half of patients with penetrating hollow viscus injuries. Despite major advances in the operative management of penetrating colon wounds, there remains discussion regarding the appropriate treatment of destructive colon injuries, with a significant amount of scientific evidence supporting segmental resection with primary anastomosis in most patients without comorbidities or large transfusion requirement. Although literature is sparse concerning the management of blunt colon injuries, some studies have shown operative decision based on an algorithm originally defined for penetrating wounds should be considered in blunt colon injuries. The optimal management of colonic injuries in patients requiring damage control surgery (DCS) also remains controversial. Studies have recently reported that there is no increased risk compared with patients treated without DCS if fascial closure is completed on the first reoperation, or that a management algorithm for penetrating colon wounds is probably efficacious for colon injuries in the setting of DCS as well.

  16. Conservative management of colonic injury during percutaneous ...

    African Journals Online (AJOL)

    M. Elghoneimy

    2016-02-22

    Feb 22, 2016 ... Patients' records were searched for the occurrence of colonic injury. Records were ... tion to opacify the system and the percutaneous renal access was .... identify the presence of a retrorenal colon, yet the rarity of such a.

  17. Microbial accumulation of uranium

    International Nuclear Information System (INIS)

    Zhang Wei; Dong Faqin; Dai Qunwei

    2005-01-01

    The mechanism of microbial accumulation of uranium and the effects of some factors (including pH, initial uranium concentration, pretreatment of bacteria, and so on) on microbial accumulation of uranium are discussed briefly. The research direction and application prospect are presented. (authors)

  18. MICROBIAL FUEL CELL

    DEFF Research Database (Denmark)

    2008-01-01

    A novel microbial fuel cell construction for the generation of electrical energy. The microbial fuel cell comprises: (i) an anode electrode, (ii) a cathode chamber, said cathode chamber comprising an in let through which an influent enters the cathode chamber, an outlet through which an effluent...

  19. Microbial control of pollution

    Energy Technology Data Exchange (ETDEWEB)

    Fry, J C; Gadd, G M; Herbert, R A; Jones, C W; Watson-Craik, I A [eds.

    1992-01-01

    12 papers are presented on the microbial control of pollution. Topics covered include: bioremediation of oil spills; microbial control of heavy metal pollution; pollution control using microorganisms and magnetic separation; degradation of cyanide and nitriles; nitrogen removal from water and waste; and land reclamation and restoration.

  20. Prehistoric human colonization of India

    Indian Academy of Sciences (India)

    Unknown

    J. Biosci. | Vol. 26 | No. 4 | Suppl. | November 2001. V N Misra. 492 ... humans differ from the other apes in their upright posture, ... characterized by Levallois flakes and blades and by the ... and the coastal region running parallel to them, northeast ..... November 2001. Prehistoric human colonization of India. 497. Figure 1.

  1. In vitro efficacy of an anti-microbial solution in prevention of micro ...

    African Journals Online (AJOL)

    Aim: To evaluate the In vitro efficacy of a new biologically acceptable Anti Microbial-Solution (AMS) for prevention of colonization of polymeric denture base materials. Materials and methods: Sample discs of 6.25mm in diameter and 2mm thick were sectioned from molded rods using two types of Poly Methylmethacrylate ...

  2. Antibiotics in 16-day-old broilers temporarily affect microbial and immune parameters in the gut

    NARCIS (Netherlands)

    Wisselink, H.J.; Cornelissen, J.B.W.J.; Mevius, D.J.; Smits, M.A.; Smidt, H.; Rebel, Johanna M.J.

    2017-01-01

    Animal health benefits from a stable intestinal homeostasis, for which proper development and functioning of the intestinal microbiota and immune system are essential. It has been established that changes in microbial colonization in early life (the first 2 wk post hatch) impacts the functioning of

  3. The relative importance of exogenous and substrate-derived nitrogen for microbial growth during leaf decomposition

    Science.gov (United States)

    B.M. Cheever; J. R. Webster; E. E. Bilger; S. A. Thomas

    2013-01-01

    Heterotrophic microbes colonizing detritus obtain nitrogen (N) for growth by assimilating N from their substrate or immobilizing exogenous inorganic N. Microbial use of these two pools has different implications for N cycling and organic matter decomposition in the face of the global increase in biologically available N. We used sugar maple leaves labeled with

  4. Acute pseudo-obstruction of the colon

    International Nuclear Information System (INIS)

    Beese, M.; Heller, M.

    1988-01-01

    The radiological correlate to the pseudo-obstruction of the colon is not specific, but it does supply a pointer to the disease of it shows dilation of the caecum, colon ascendens and colon transversum with air-pockets and reflected imaging as well as a usually not dilated colon descendens with remarkably little air. To make the diagnosis quite sure we must exclude intestinal obstruction by using X-ray contrast media or by coloscopy. (orig./GDG) [de

  5. Laparoscopic colectomy for transverse colon carcinoma.

    Science.gov (United States)

    Zmora, O; Bar-Dayan, A; Khaikin, M; Lebeydev, A; Shabtai, M; Ayalon, A; Rosin, D

    2010-03-01

    Laparoscopic resection of transverse colon carcinoma is technically demanding and was excluded from most of the large trials of laparoscopic colectomy. The aim of this study was to assess the safety, feasibility, and outcome of laparoscopic resection of carcinoma of the transverse colon. A retrospective review was performed to identify patients who underwent laparoscopic resection of transverse colon carcinoma. These patients were compared to patients who had laparoscopic resection for right and sigmoid colon carcinoma. In addition, they were compared to a historical series of patients who underwent open resection for transverse colon cancer. A total of 22 patients underwent laparoscopic resection for transverse colon carcinoma. Sixty-eight patients operated for right colon cancer and 64 operated for sigmoid colon cancer served as comparison groups. Twenty-four patients were identified for the historical open group. Intraoperative complications occurred in 4.5% of patients with transverse colon cancer compared to 5.9% (P = 1.0) and 7.8% (P = 1.0) of patients with right and sigmoid colon cancer, respectively. The early postoperative complication rate was 45, 50 (P = 1.0), and 37.5% (P = 0.22) in the three groups, respectively. Conversion was required in 1 (5%) patient in the laparoscopic transverse colon group. The conversion rate and late complications were not significantly different in the three groups. There was no significant difference in the number of lymph nodes harvested in the laparoscopic and open groups. Operative time was significantly longer in the laparoscopic transverse colectomy group when compared to all other groups (P = 0.001, 0.008, and transverse colectomy, respectively). The results of laparoscopic colon resection for transverse colon carcinoma are comparable to the results of laparoscopic resection of right or sigmoid colon cancer and open resection of transverse colon carcinoma. These results suggest that laparoscopic resection of transverse

  6. Standard colonic lavage alters the natural state of mucosal-associated microbiota in the human colon.

    Directory of Open Access Journals (Sweden)

    Laura Harrell

    Full Text Available Past studies of the human intestinal microbiota are potentially confounded by the common practice of using bowel-cleansing preparations. We examined if colonic lavage changes the natural state of enteric mucosal-adherent microbes in healthy human subjects.Twelve healthy individuals were divided into three groups; experimental group, control group one, and control group two. Subjects in the experimental group underwent an un-prepped flexible sigmoidoscopy with biopsies. Within two weeks, subjects were given a standard polyethylene glycol-based bowel cleansing preparation followed by a second flexible sigmoidoscopy. Subjects in control group one underwent two un-prepped flexible sigmoidoscopies within one week. Subjects in the second control group underwent an un-prepped flexible sigmoidoscopy followed by a second flexible sigmoidoscopy after a 24-hour clear liquid diet within one week. The mucosa-associated microbial communities from the two procedures in each subject were compared using 16S rRNA gene based terminal restriction fragment length polymorphism (T-RFLP, and library cloning and sequencing.Clone library sequencing analysis showed that there were changes in the composition of the mucosa-associated microbiota in subjects after colonic lavage. These changes were not observed in our control groups. Standard bowel preparation altered the diversity of mucosa-associated microbiota. Taxonomic classification did not reveal significant changes at the phylum level, but there were differences observed at the genus level.Standard bowel cleansing preparation altered the mucosal-adherent microbiota in all of our subjects, although the degree of change was variable. These findings underscore the importance of considering the confounding effects of bowel preparation when designing experiments exploring the gut microbiota.

  7. Mutualistic interaction between Salmonella enterica and Aspergillus niger and its effects on Zea mays colonization.

    Science.gov (United States)

    Balbontín, Roberto; Vlamakis, Hera; Kolter, Roberto

    2014-11-01

    Salmonella Typhimurium inhabits a variety of environments and is able to infect a broad range of hosts. Throughout its life cycle, some hosts can act as intermediates in the path to the infection of others. Aspergillus niger is a ubiquitous fungus that can often be found in soil or associated to plants and microbial consortia. Recently, S. Typhimurium was shown to establish biofilms on the hyphae of A. niger. In this work, we have found that this interaction is stable for weeks without a noticeable negative effect on either organism. Indeed, bacterial growth is promoted upon the establishment of the interaction. Moreover, bacterial biofilms protect the fungus from external insults such as the effects of the anti-fungal agent cycloheximide. Thus, the Salmonella-Aspergillus interaction can be defined as mutualistic. A tripartite gnotobiotic system involving the bacterium, the fungus and a plant revealed that co-colonization has a greater negative effect on plant growth than colonization by either organism in dividually. Strikingly, co-colonization also causes a reduction in plant invasion by S. Typhimurium. This work demonstrates that S. Typhimurium and A. niger establish a mutualistic interaction that alters bacterial colonization of plants and affects plant physiology. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  8. Bacteria from diverse habitats colonize and compete in the mouse gut.

    Science.gov (United States)

    Seedorf, Henning; Griffin, Nicholas W; Ridaura, Vanessa K; Reyes, Alejandro; Cheng, Jiye; Rey, Federico E; Smith, Michelle I; Simon, Gabriel M; Scheffrahn, Rudolf H; Woebken, Dagmar; Spormann, Alfred M; Van Treuren, William; Ursell, Luke K; Pirrung, Megan; Robbins-Pianka, Adam; Cantarel, Brandi L; Lombard, Vincent; Henrissat, Bernard; Knight, Rob; Gordon, Jeffrey I

    2014-10-09

    To study how microbes establish themselves in a mammalian gut environment, we colonized germ-free mice with microbial communities from human, zebrafish, and termite guts, human skin and tongue, soil, and estuarine microbial mats. Bacteria from these foreign environments colonized and persisted in the mouse gut; their capacity to metabolize dietary and host carbohydrates and bile acids correlated with colonization success. Cohousing mice harboring these xenomicrobiota or a mouse cecal microbiota, along with germ-free "bystanders," revealed the success of particular bacterial taxa in invading guts with established communities and empty gut habitats. Unanticipated patterns of ecological succession were observed; for example, a soil-derived bacterium dominated even in the presence of bacteria from other gut communities (zebrafish and termite), and human-derived bacteria colonized germ-free bystander mice before mouse-derived organisms. This approach can be generalized to address a variety of mechanistic questions about succession, including succession in the context of microbiota-directed therapeutics. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Genetic Control of Plant Root Colonization by the Biocontrol agent, Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Benjamin J.; Fletcher, Meghan; Waters, Jordan; Wetmore, Kelly; Blow, Matthew J.; Deutschbauer, Adam M.; Dangl, Jeffry L.; Visel, Axel

    2015-03-19

    Plant growth promoting rhizobacteria (PGPR) are a critical component of plant root ecosystems. PGPR promote plant growth by solubilizing inaccessible minerals, suppressing pathogenic microorganisms in the soil, and directly stimulating growth through hormone synthesis. Pseudomonas fluorescens is a well-established PGPR isolated from wheat roots that can also colonize the root system of the model plant, Arabidopsis thaliana. We have created barcoded transposon insertion mutant libraries suitable for genome-wide transposon-mediated mutagenesis followed by sequencing (TnSeq). These libraries consist of over 105 independent insertions, collectively providing loss-of-function mutants for nearly all genes in the P.fluorescens genome. Each insertion mutant can be unambiguously identified by a randomized 20 nucleotide sequence (barcode) engineered into the transposon sequence. We used these libraries in a gnotobiotic assay to examine the colonization ability of P.fluorescens on A.thaliana roots. Taking advantage of the ability to distinguish individual colonization events using barcode sequences, we assessed the timing and microbial concentration dependence of colonization of the rhizoplane niche. These data provide direct insight into the dynamics of plant root colonization in an in vivo system and define baseline parameters for the systematic identification of the bacterial genes and molecular pathways using TnSeq assays. Having determined parameters that facilitate potential colonization of roots by thousands of independent insertion mutants in a single assay, we are currently establishing a genome-wide functional map of genes required for root colonization in P.fluorescens. Importantly, the approach developed and optimized here for P.fluorescens>A.thaliana colonization will be applicable to a wide range of plant-microbe interactions, including biofuel feedstock plants and microbes known or hypothesized to impact on biofuel-relevant traits including biomass productivity

  10. CALCIUM AND THE PREVENTION OF COLON CANCER

    NARCIS (Netherlands)

    WELBERG, JWM; KLEIBEUKER, JH; VANDERMEER, R; MULDER, NH; DEVRIES, EGE

    1991-01-01

    Diet is a major determinant of colon cancer risk. Calcium may protect against colon cancer, presumably by binding cytotoxic bile acids and fatty acids. Numerous studies support this proposition. In subjects at risk for colon cancer oral calcium supplementation has been shown to reduce rectal

  11. Congenital Diverticular Disease of the Entire Colon

    Directory of Open Access Journals (Sweden)

    A. Patel

    2013-01-01

    Full Text Available Congenital or true colonic diverticulosis is a rare condition typified by the preservation of the colonic wall architecture within the diverticular outpouching. Cases of multiple jejunal diverticula have been reported as well as cases of solitary giant diverticula of the colon. There have been no reports in the literature of pancolonic congenital diverticulosis.

  12. Comparing Expert and Novice Driving Behavior in a Driving Simulator

    Directory of Open Access Journals (Sweden)

    Hiran B. Ekanayake

    2014-02-01

    Full Text Available This paper presents a study focused on comparing driving behavior of expert and novice drivers in a mid-range driving simulator with the intention of evaluating the validity of driving simulators for driver training. For the investigation, measurements of performance, psychophysiological measurements, and self-reported user experience under different conditions of driving tracks and driving sessions were analyzed. We calculated correlations between quantitative and qualitative measures to enhance the reliability of the findings. The experiment was conducted involving 14 experienced drivers and 17 novice drivers. The results indicate that driving behaviors of expert and novice drivers differ from each other in several ways but it heavily depends on the characteristics of the task. Moreover, our belief is that the analytical framework proposed in this paper can be used as a tool for selecting appropriate driving tasks as well as for evaluating driving performance in driving simulators.

  13. A novel dissolution media for testing drug release from a nanostructured polysaccharide-based colon specific drug delivery system: an approach to alternative colon media

    Directory of Open Access Journals (Sweden)

    Kotla NG

    2016-03-01

    Full Text Available Niranjan G Kotla,1,2 Sima Singh,1,3 Balaji Maddiboyina,4 Omprakash Sunnapu,2 Thomas J Webster5,6 1School of Pharmaceutical Sciences, Lovely Professional University, Punjab, India; 2Technologies for the Advancement of Science, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, Karnataka, India; 3Department of Pharmaceutical Sciences, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India; 4Department of Pharmaceutics, Vishwabharathi College of Pharmaceutical Sciences, Guntur, Andhra Pradesh, India; 5Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 6Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: The aim of this study was to develop a novel microbially triggered and animal-sparing dissolution method for testing of nanorough polysaccharide-based micron granules for colonic drug delivery. In this method, probiotic cultures of bacteria present in the colonic region were prepared and added to the dissolution media and compared with the performance of conventional dissolution methodologies (such as media with rat cecal and human fecal media. In this study, the predominant species (such as Bacteroides, Bifidobacterium, Lactobacillus species, Eubacterium and Streptococcus were cultured in 12% w/v skimmed milk powder and 5% w/v grade “A” honey. Approximately 1010–1011 colony forming units m/L of probiotic culture was added to the dissolution media to test the drug release of polysaccharide-based formulations. A USP dissolution apparatus I/II using a gradient pH dissolution method was used to evaluate drug release from formulations meant for colonic drug delivery. Drug release of guar gum/Eudragit FS30D coated 5-fluorouracil granules was assessed under gastric and small intestine conditions within a simulated colonic environment involving fermentation testing with the probiotic culture. The results with the probiotic system were

  14. Driving skills after whiplash.

    Science.gov (United States)

    Gimse, R; Bjørgen, I A; Straume, A

    1997-09-01

    Previous studies have shown that some persons with longlasting problems after whiplash have changed eye movements. These changes have been related to disturbance of the posture control system. The question raised in the present study is whether such disturbances can influence daily life functions connected with balance, position and external movements, such as car driving. A group of 23 persons with disturbed eye movements due to whiplash injury, was tested in a driving simulator, together with a closely matched control group. The results revealed significant differences between the two groups with respect to response times to the traffic signs presented, identification of type of sign, as well as steering precision while the subjects' attention was directed to the process of identifying the signs. Alternative explanations such as driving experience, pain, medication or malingering are at least partly controlled for, but cannot completely be ruled out. A distorted posture control system leading to disturbance of eye movements seems to be the most likely primary causative factor, but these disturbances are most certainly complexly determined. Reduced attention capacity is considered to be a mediating secondary factor. Registration of eye movements may be a useful diagnostic tool to evaluate driving skill after whiplash.

  15. Gaze-controlled Driving

    DEFF Research Database (Denmark)

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...

  16. Gas turbine drives

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Developments in gas turbine drives are reviewed, e.g., low weight per unit power and thrust-weight ratio, fast availability of the maximum speed, absolute resistance to cold and to droplet formation vibrationeless run, and low exhaust gas temperatures. Applications in aeronautic engineering (turbofan), power stations, marine propulsion systems, railways and road transportation vehicles are mentioned.

  17. Chaos in drive systems

    Directory of Open Access Journals (Sweden)

    Kratochvíl C.

    2007-10-01

    Full Text Available The purpose of this article is to provide an elementary introduction to the subject of chaos in the electromechanical drive systems. In this article, we explore chaotic solutions of maps and continuous time systems. These solutions are also bounded like equilibrium, periodic and quasiperiodic solutions.

  18. Electric Drive Study

    Science.gov (United States)

    1987-03-01

    compound promises to reduce weight of future permanent magnet motors by 20 to 30 percent; a similar reduction is expected in size (approximately 20...drive systems. The AC permanent magnet (brushless DC motor) is rapidly evolving and will replace most electrically excited machines. Permanent magnet motors using

  19. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-11

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  20. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-01

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  1. Driving While Intoxicated.

    Science.gov (United States)

    Brick, John

    Alcohol intoxication increases the risk of highway accidents, the relative risk of crash probability increasing as a function of blood alcohol content (BAC). Because alcohol use is more prevalent than use of other drugs, more is known about the relationship between alcohol use and driving. Most states presume a BAC of .10% to be evidence of drunk…

  2. Temperature and redox effect on mineral colonization in Juan de Fuca Ridge flank subsurface crustal fluids

    Directory of Open Access Journals (Sweden)

    Jean-Paul eBaquiran

    2016-03-01

    Full Text Available To examine microbe-mineral interactions in subsurface oceanic crust, we evaluated microbial colonization on crustal minerals that were incubated in borehole fluids for one year at the seafloor wellhead of a crustal borehole observatory (IODP Hole U1301A, Juan de Fuca Ridge flank as compared to an experiment that was not exposed to subsurface crustal fluids (at nearby IODP Hole U1301B. In comparison to previous studies at these same sites, this approach allowed assessment of the effects of temperature, fluid chemistry, and/or mineralogy on colonization patterns of different mineral substrates, and an opportunity to verify the approach of deploying colonization experiments at an observatory wellhead at the seafloor instead of within the borehole. The Hole U1301B deployment did not have biofilm growth, based on microscopy and DNA extraction, thereby confirming the integrity of the colonization design against bottom seawater intrusion. In contrast, the Hole U1301A deployment supported biofilms dominated by Epsilonproteobacteria (43.5% of 370 16S rRNA gene clone sequences and Gammaproteobacteria (29.3%. Sequence analysis revealed overlap in microbial communities between different minerals incubated at the Hole U1301A wellhead, indicating that mineralogy did not separate biofilm structure within the one-year colonization experiment. Differences in the Hole U1301A wellhead biofilm community composition relative to previous studies from within the borehole using similar mineral substrates suggest that temperature and the diffusion of dissolved oxygen through plastic components influenced the mineral colonization experiments positioned at the wellhead. This highlights the capacity of low abundance crustal fluid taxa to rapidly establish communities on diverse mineral substrates under changing environmental conditions such as from temperature and oxygen.

  3. Spruce colonization at treeline: where do those seeds come from?

    Science.gov (United States)

    Piotti, A; Leonardi, S; Piovani, P; Scalfi, M; Menozzi, P

    2009-08-01

    At treeline, selection by harsh environmental conditions sets an upward limit to arboreal vegetation. Increasing temperatures and the decline of traditional animal raising have favoured an upward shift of treeline in the last decades. These circumstances create a unique opportunity to study the balance of the main forces (selection and gene flow) that drive tree migration. We conducted a parentage analysis sampling and genotyping with five microsatellite markers in all Norway spruce individuals (342 juveniles and 23 adults) found in a recently colonized treeline area (Paneveggio forest, Eastern Alps, Italy). Our goal was to evaluate local reproductive success versus gene flow from the outside. We were able to identify both parents among local adults for only 11.1% of the juveniles. In the gamete pool we sampled, two-thirds were not produced locally. Effective seed dispersal distance distribution was characterized by a peak far from the seed source (mean 344.66 m+/-191.02 s.d.). Reproductive success was skewed, with six local adults that generated almost two-thirds (62.4%) of juveniles with local parents. Our findings indicate that, although a few local adults seem to play an important role in the colonization process at treeline, large levels of gene flow from outside were maintained, suggesting that the potential advantages of local adults (such as local adaptation, proximity to the colonization area, phenological synchrony) did not prevent a large gamete immigration.

  4. Magnetic Separation for the Direct Observation of Mineral-Associated Microbial Diversity

    Science.gov (United States)

    Harrison, B. K.; Orphan, V.

    2006-12-01

    Previous studies have demonstrated that microorganisms may selectively colonize mineral surfaces in diverse environments. Mineral substrates may serve as an important source of limiting nutrients or provide electron acceptors and donors for dissimilatory reactions. This work presents a new method for characterizing the microbial diversity associated with specific components in environmental samples. Minerals are concentrated from the bulk sample according to magnetic susceptibility, resulting in compositionally distinct partitions. The microbial communities associated with these partitions are subsequently characterized using molecular techniques. Initial testing of samples from active and dormant hydrothermal chimney structures from the Lau and Fiji Basins show that mineral components may be concentrated from bulk samples without concealing pre-existing patterns of selective colonization. 16S gene surveys from environmental clone libraries reveal distinct colonization patterns for thermophilic archaea and bacteria between sulfide mineral partitions. This method offers a unique tool discerning the role of mineral composition in surface-associated diversity.

  5. Internal Porosity of Mineral Coating Supports Microbial Activity in Rapid Sand Filters for Groundwater Treatment

    DEFF Research Database (Denmark)

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin

    2014-01-01

    of the filter material. The volumetric NH4+ removal rate also increased with the degree of mineral coating. Consistently, bacterial 16S rRNA and amoA abundances positively correlated with increased mineral coating levels. Microbial colonization could be visualized mainly within the outer periphery (60.6 ± 35......, and abundance of microbiota. This study reveals that a mineral coating can positively affect the colonization and activity of microbial communities in rapid sand filters. To understand this effect, we investigated the abundance, spatial distribution, colonization, and diversity of all and of nitrifying...... prokaryotes in filter material with various degrees of mineral coating. We also examined the physical and chemical characteristics of the mineral coating. The amount of mineral coating correlated positively with the internal porosity, the packed bulk density, and the biologically available surface area...

  6. The microbial diversity, distribution, and ecology of permafrost in China: a review.

    Science.gov (United States)

    Hu, Weigang; Zhang, Qi; Tian, Tian; Cheng, Guodong; An, Lizhe; Feng, Huyuan

    2015-07-01

    Permafrost in China mainly located in high-altitude areas. It represents a unique and suitable ecological niche that can be colonized by abundant microbes. Permafrost microbial community varies across geographically separated locations in China, and some lineages are novel and possible endemic. Besides, Chinese permafrost is a reservoir of functional microbial groups involved in key biogeochemical cycling processes. In future, more work is necessary to determine if these phylogenetic groups detected by DNA-based methods are part of the viable microbial community, and their functional roles and how they potentially respond to climate change. This review summaries recent studies describing microbial biodiversity found in permafrost and associated environments in China, and provides a framework for better understanding the microbial ecology of permafrost.

  7. Control of Colon Cancer Progression by the Colon Microbiome

    Science.gov (United States)

    2015-08-01

    Award  Number:    W81XWH-­14-­1-­0235   TITLE:      Control of Colon Cancer Progression by the Colon Microbiome PRINCIPAL  INVESTIGATOR:    Frank  J... Microbiome Table  of  Contents   Page   1. Introduction………………………………………………………….4 2. Keywords…………………………………………………………….5 3. Accomplishments………..…………………………………………5

  8. Rod drive and latching mechanism

    International Nuclear Information System (INIS)

    Veronesi, L.; Sherwood, D.G.

    1982-01-01

    Hydraulic drive and latching mechanisms for driving reactivity control mechanisms in nuclear reactors are described. Preferably, the pressurized reactor coolant is utilized to raise the drive rod into contact with and to pivot the latching mechanism so as to allow the drive rod to pass the latching mechanism. The pressure in the housing may then be equalized which allows the drive rod to move downwardly into contact with the latching mechanism but to hold the shaft in a raised position with respect to the reactor core. Once again, the reactor coolant pressure may be utilized to raise the drive rod and thus pivot the latching mechanism so that the drive rod passes above the latching mechanism. Again, the mechanism pressure can be equalized which allows the drive rod to fall and pass by the latching mechanism so that the drive rod approaches the reactor core. (author)

  9. Microbial Biotransformation of a Polyphenol-Rich Potato Extract Affects Antioxidant Capacity in a Simulated Gastrointestinal Model

    Directory of Open Access Journals (Sweden)

    Joelle Khairallah

    2018-03-01

    Full Text Available A multistage human gastrointestinal model was used to digest a polyphenol-rich potato extract containing chlorogenic acid, caffeic acid, ferulic acid, and rutin as the primary polyphenols, to assess for their microbial biotransformation and to measure changes in antioxidant capacity in up to 24 h of digestion. The biotransformation of polyphenols was assessed by liquid chromatography–mass spectrometry. Antioxidant capacity was measured by the ferric reducing antioxidant power (FRAP assay. Among the colonic reactors, parent (polyphenols were detected in the ascending (AC, but not the transverse (TC or descending (DC colons. The most abundant microbial phenolic metabolites in all colonic reactors included derivatives of propionic acid, acetic acid, and benzoic acid. As compared to the baseline, an earlier increase in antioxidant capacity (T = 8 h was seen in the stomach and small intestine vessels as compared to the AC (T = 16 h and TC and DC (T = 24 h. The increase in antioxidant capacity observed in the DC and TC can be linked to the accumulation of microbial smaller-molecular-weight phenolic catabolites, as the parent polyphenolics had completely degraded in those vessels. The colonic microbial digestion of potato-based polyphenols could lead to improved colonic health, as this generates phenolic metabolites with significant antioxidant potential.

  10. Transverse loop colostomy and colonic motility.

    Science.gov (United States)

    Pucciani, F; Ringressi, M N; Maltinti, G; Bechi, P

    2014-11-01

    The motility of the defunctionalized colon, distal to transverse loop colostomy, has never been studied "in vivo." The aim of our study was to evaluate the influence of transverse loop colostomy on colonic motility. Thirteen patients were examined before stoma closure by means of clinical evaluation and colonic manometry; we studied both the right and distal colon in both fasting and fed patients in order to detect motor activity. Quantitative and qualitative manometric analyses showed that the diverted colon had motor activity even if no regular colonic motor pattern was observed. The spreading of aboral propagated contractions (PCs) was sometimes recorded from the right colon to the distal colon. The response of the proximal and distal colon to a standard meal, when compared to fasting values, increased more than 40 and 35 %, respectively. Stool and gas ejections from the colostomy were never related to a particular type of colonic motility: Motor quiescence such as PCs was chaotically related to stool escape. In conclusion, motility of the defunctionalized colon is preserved in patients with transverse loop colostomy.

  11. Electrical drives for direct drive renewable energy systems

    CERN Document Server

    Mueller, Markus

    2013-01-01

    Wind turbine gearboxes present major reliability issues, leading to great interest in the current development of gearless direct-drive wind energy systems. Offering high reliability, high efficiency and low maintenance, developments in these direct-drive systems point the way to the next generation of wind power, and Electrical drives for direct drive renewable energy systems is an authoritative guide to their design, development and operation. Part one outlines electrical drive technology, beginning with an overview of electrical generators for direct drive systems. Principles of electrical design for permanent magnet generators are discussed, followed by electrical, thermal and structural generator design and systems integration. A review of power electronic converter technology and power electronic converter systems for direct drive renewable energy applications is then conducted. Part two then focuses on wind and marine applications, beginning with a commercial overview of wind turbine drive systems and a...

  12. Driving towards ecotechnologies.

    Science.gov (United States)

    Najjar, Devora A; Normandin, Avery M; Strait, Elizabeth A; Esvelt, Kevin M

    2017-12-01

    The prospect of using genetic methods to target vector, parasite, and reservoir species offers tremendous potential benefits to public health, but the use of genome editing to alter the shared environment will require special attention to public perception and community governance in order to benefit the world. Public skepticism combined with the media scrutiny of gene drive systems could easily derail unpopular projects entirely, especially given the potential for trade barriers to be raised against countries that employ self-propagating gene drives. Hence, open and community-guided development of thoughtfully chosen applications is not only the most ethical approach, but also the most likely to overcome the economic, social, and diplomatic barriers. Here we review current and past attempts to alter ecosystems using biological methods, identify key determinants of social acceptance, and chart a stepwise path for developers towards safe and widely supported use.

  13. Control rod drives

    International Nuclear Information System (INIS)

    Asano, Hiromitsu.

    1979-01-01

    Purpose: To drive control rods at an optimum safety speed corresponding to the reactor core output. Constitution: The reactor power is detected by a neutron detector and the output signal is applied to a process computer. The process computer issues a signal representing the reactor core output, which is converted through a function generator into a signal representing the safety speed of control rods. The converted signal is further supplied to a V/F converter and converted into a pulse signal. The pulse signal is inputted to a step motor driving circuit, which actuates a step motor to operate the control rods always at a safety speed corresponding to the reactor core power. (Furukawa, Y.)

  14. Drive-by-Downloads

    Energy Technology Data Exchange (ETDEWEB)

    Narvaez, Julia; Endicott-Popovsky, Barbara E.; Seifert, Christian; Aval, Chiraag U.; Frincke, Deborah A.

    2010-02-01

    Abstract: Drive-by-downloads are malware that push, and then execute, malicious code on a client system without the user's consent. The purpose of this paper is to introduce a discussion of the usefulness of antivirus software for detecting the installation of such malware, providing groundwork for future studies. Client honeypots collected drive-by malware which was then evaluated using common antivirus products. Initial analysis showed that most of such antivirus products identified less than 70% of these highly polymorphic malware programs. Also, it was observed that the antivirus products tested, even when successfully detecting this malware, often failed to classify it, leading to the conclusion that further work could involve not only developing new behavioral detection technologies, but also empirical studies that improve general understanding of these threats. Toward that end, one example of malicious code was analyzed behaviorally to provide insight into next steps for the future direction of this research.

  15. Safety rod driving device

    International Nuclear Information System (INIS)

    Murakami, Kiyonobu; Kurosaki, Akira.

    1988-01-01

    Purpose: To rapidly insert safety rods for a criticality experiment device into a reactor core container to stop the criticality reaction thereby prevent reactivity accidents. Constitution: A cylinder device having a safety rod as a cylinder rod attached with a piston at one end is constituted. The piston is elevated by pressurized air and attracted and fixed by an electromagnet which is a stationary device disposed at the upper portion of the cylinder. If the current supply to the electromagnet is disconnected, the safety rod constituting the cylinder rod is fallen together with the piston to the lower portion of the cylinder. Since the cylinder rod driving device has neither electrical motor nor driving screw as in the conventional device, necessary space can be reduced and the weight is decreased. In addition, since the inside of the nuclear reactor can easily be shielded completely from the external atmosphere, leakage of radioactive materials can be prevented. (Horiuchi, T.)

  16. Control rod drive mechanism

    International Nuclear Information System (INIS)

    Futatsugi, Masao; Goto, Mikihiko.

    1976-01-01

    Purpose: To provide a control rod drive mechanism using water as an operating source, which prevents a phenomenon for forming two-layers of water in the neighbourhood of a return nozzle in a reactor to limit formation of excessive thermal stress to improve a safety. Constitution: In the control rod drive mechanism of the present invention, a heating device is installed in the neighbourhood of a pressure container for a reactor. This heating device is provided to heat return water in the reactor to a level equal to the temperature of reactor water thereby preventing a phenomenon for forming two-layers of water in the reactor. This limits formation of thermal stress in the return nozzle in the reactor. Accordingly, it is possible to minimize damages in the return nozzle portion and yet a possibility of failure in reactor water. (Kawakami, Y.)

  17. A rotary drive

    International Nuclear Information System (INIS)

    Causer, R.

    1983-01-01

    A rotary drive for a manipulator or teleoperator comprises a ring member freely rotatable about an eccentric boss extending from an input driver shaft. The ring member has a tapered rim portion wedged between two resiliently biassed friction rings of larger diameter than the ring member and coaxial with the driver shaft, and the ring member is rotatably connected to an output driven shaft. The rotary drive provides a considerable velocity ratio, and also provides a safety feature in that friction between the rim portion and the friction rings only causes rotation of the driven shaft if the load on the driven shaft is less than a certain limiting value. This limiting value may be varied by adjusting the resilient bias on the friction rings. (author)

  18. Driving and engine cycles

    CERN Document Server

    Giakoumis, Evangelos G

    2017-01-01

    This book presents in detail the most important driving and engine cycles used for the certification and testing of new vehicles and engines around the world. It covers chassis and engine-dynamometer cycles for passenger cars, light-duty vans, heavy-duty engines, non-road engines and motorcycles, offering detailed historical information and critical review. The book also provides detailed examples from SI and diesel engines and vehicles operating during various cycles, with a focus on how the engine behaves during transients and how this is reflected in emitted pollutants, CO2 and after-treatment systems operation. It describes the measurement methods for the testing of new vehicles and essential information on the procedure for creating a driving cycle. Lastly, it presents detailed technical specifications on the most important chassis-dynamometer cycles around the world, together with a direct comparison of those cycles.

  19. Bacterial Colonization of Disposable Soft Contact Lenses Is Greater during Corneal Infiltrative Events than during Asymptomatic Extended Lens Wear

    Science.gov (United States)

    Sankaridurg, Padmaja R.; Sharma, Savitri; Willcox, Mark; Naduvilath, Thomas J.; Sweeney, Deborah F.; Holden, Brien A.; Rao, Gullapalli N.

    2000-01-01

    Microorganisms, especially gram-negative bacteria, are considered to play a role in the etiology of certain corneal infiltrative events (CIEs) observed during soft contact lens wear. This study explored the possibility of microbial colonization of soft contact lenses as a risk factor leading to CIEs. In a clinical trial conducted from March 1993 to January 1996, 330 subjects wore disposable soft contact lenses on a 6-night extended-wear and disposal schedule. During this period, 4,321 lenses (118 during CIEs; 4,203 during asymptomatic lens wear) were recovered aseptically and analyzed for microbial colonization. A greater percentage of lenses were free from microbial colonization during asymptomatic wear than during CIEs (42 versus 23%; P bacteria, gram-negative bacteria and fungi was greater during CIEs than during asymptomatic lens wear (P bacteria were isolated most frequently and were usually normal external ocular microbiota. Of the gram-positive bacteria, the incidence of Streptococcus pneumoniae was greater during CIE than during asymptomatic wear (7.6 versus 0.6%; P bacteria were seen in few cases during asymptomatic wear, their incidence during CIE in comparison to asymptomatic wear was substantial and significant (23.7 versus 3.8%; P bacteria or S. pneumoniae. Colonization of soft contact lenses with pathogenic bacteria, especially gram-negative bacteria and S. pneumoniae, appears to be a significant risk factor leading to CIE. PMID:11101574

  20. Driving electrostatic transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes power stages and bias configurations suitable for driving an electrostatic transducer. Measurement results of a 300 V prototype amplifier are shown. Measuring THD across a high impedance source is discussed...

  1. Low Microbial Diversity and Abnormal Microbial Succession Is Associated with Necrotizing Enterocolitis in Preterm Infants

    Science.gov (United States)

    Dobbler, Priscila T.; Procianoy, Renato S.; Mai, Volker; Silveira, Rita C.; Corso, Andréa L.; Rojas, Bruna S.; Roesch, Luiz F. W.

    2017-01-01

    Despite increased efforts, the diverse etiologies of Necrotizing Enterocolitis (NEC) have remained largely elusive. Clinical predictors of NEC remain ill-defined and currently lack sufficient specificity. The development of a thorough understanding of initial gut microbiota colonization pattern in preterm infants might help to improve early detection or prediction of NEC and its associated morbidities. Here we compared the fecal microbiota successions, microbial diversity, abundance and structure of newborns that developed NEC with preterm controls. A 16S rRNA based microbiota analysis was conducted in a total of 132 fecal samples that included the first stool (meconium) up until the 5th week of life or NEC diagnosis from 40 preterm babies (29 controls and 11 NEC cases). A single phylotype matching closest to the Enterobacteriaceae family correlated strongly with NEC. In DNA from the sample with the greatest abundance of this phylotype additional shotgun metagenomic sequencing revealed Citrobacter koseri and Klebsiella pneumoniae as the dominating taxa. These two taxa might represent suitable microbial biomarker targets for early diagnosis of NEC. In NEC cases, we further detected lower microbial diversity and an abnormal succession of the microbial community before NEC diagnosis. Finally, we also detected a disruption in anaerobic microorganisms in the co-occurrence network of meconium samples from NEC cases. Our data suggest that a strong dominance of Citrobacter koseri and/or Klebsiella pneumoniae, low diversity, low abundance of Lactobacillus, as well as an altered microbial-network structure during the first days of life, correlate with NEC risk in preterm infants. Confirmation of these findings in other hospitals might facilitate the development of a microbiota based screening approach for early detection of NEC. PMID:29187842

  2. Schwannoma of the sigmoid colon

    OpenAIRE

    Çakır, Tuğrul; Aslaner, Arif; Yaz, Müjgan; Gündüz, Umut rıza

    2015-01-01

    Colonic schwannomas are very rare gastrointestinal tumours originating from Schwann cells, which form the neural sheath. Primary schwannomas of the lower gastrointestinal tract are very rare and usually benign in nature. However, if they are not surgically removed, malign degeneration can occur. We report a case of a 79-year-old woman who presented to our clinic with rectal bleeding and constipation. She underwent a lower gastrointestinal tract endoscopy. A mass subtotally obstructing the lum...

  3. Oral yeast colonization throughout pregnancy

    OpenAIRE

    Rio, Rute; Sim?es-Silva, Liliana; Garro, Sofia; Silva, M?rio-Jorge; Azevedo, ?lvaro; Sampaio-Maia, Benedita

    2017-01-01

    Background Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with n...

  4. Control rod drive mechanism

    International Nuclear Information System (INIS)

    Mizuno, Katsuyuki.

    1976-01-01

    Object: To restrict the reduction in performance due to stress corrosion cracks by making use of condensate produced in a turbine steam condenser. Structure: Water produced in a turbine steam condenser is forced into a condensed water desalting unit by low pressure condensate pump. The condensate is purified and then forced by a high pressure condensate pump into a feedwater heater for heating before it is returned to the reactor by a feedwater pump. Part of the condensate issuing from the condensate desalting unit is branched from the remaining portion at a point upstream the pump and is withdrawn into a control rod drive water pump after passing through a motordriven bypass valve, an orifice and a condenser water level control valve, is pressurized in the control rod drive water desalting unit and supplied to a control rod drive water pressure system. The control rod is vertically moved by the valve operation of the water pressure system. Since water of high oxygen concentration does not enter during normal operation, it is possible to prevent the stress cracking of the stainless steel apparatus. (Nakamura, S.)

  5. Motor car driving; Kraftfahrzeugfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Juergensohn, T. [Technische Univ. Berlin (Germany). ISS-Fahrzeugtechnik; Timpe, K.P. (eds.) [Technische Univ. Berlin (DE). Zentrum Mensch-Maschine-Systeme (ZMMS)

    2001-07-01

    This is the first comprehensive book on motor car driving, i.e. all aspects of motor car technology that cannot be looked at separately from the needs, characteristics and limitations of the human driver. This includes ergonomics as well as the design of the driver interface in consideration of the findings of cognitive science, problems of driving simulation in the context of simulation of technical systems, problems relating to optimal car automation up to traffic psychology. The book is in honour of Prof. Dr. Willumeit who died in summer 2000. Prof. Willumeit was one of the few scientists in Germany who had been an expert on all aspects of motor car driving for many years. [German] Erstmalig wird das Thema der Fahrzeugfuehrung geschlossen dargestellt. Die Thematik der 'Kraftfahrzeugfuehrung' umfasst in diesem Zusammenhang alle Aspekte der Kraftfahrzeugtechnik, die nicht isoliert von den Erfordernissen, Eigenschaften und Grenzen des menschlichen Fahrers betrachtet werden koennen. Dies beinhaltet u.a. Probleme der Ergonomie, aber auch Fragen nach einer kognitionswissenschaftlich unterstuetzten Schnittstellengestaltung, Fragen der Simulation des Fahrverhalten im Kontext der Simulation technischer Systeme oder Fragen einer optimalen Fahrzeugautomatisierung bis hin zu verkehrspsychologischen Aspekten. Das Buch ist als Gedenkband fuer Prof. Dr. Willumeit konzipiert, der im Sommer 2000 verstarb. Prof. Willumeit war einer der wenigen Wissenschaftler in Deutschland, der ueber viele Jahre diese Thematik der Kraftfahrzeugfuehrung in ihrer vollen Breite verfolgte. (orig.)

  6. Control rod drive

    International Nuclear Information System (INIS)

    Watando, Kosaku; Tanaka, Yuzo; Mizumura, Yasuhiro; Hosono, Kazuya.

    1975-01-01

    Object: To provide a simple and compact construction of an apparatus for driving a drive shaft inside with a magnetic force from the outside of the primary system water side. Structure: The weight of a plunger provided with an attraction plate is supported by a plunger lift spring means so as to provide a buffer action at the time of momentary movement while also permitting the load on lift coil to be constituted solely by the load on the drive shaft. In addition, by arranging the attraction plate and lift coil so that they face each other with a small gap there-between, it is made possible to reduce the size and permit efficient utilization of the attracting force. Because of the small size, cooling can be simply carried out. Further, since there is no mechanical penetration portion, there is no possibility of leakage of the primary system water. Furthermore, concentration of load on a latch pin is prevented by arranging so that with a structure the load of the control rod to be directly beared through the scrum latch. (Kamimura, M.)

  7. Oral yeast colonization throughout pregnancy.

    Science.gov (United States)

    Rio, R; Simões-Silva, L; Garro, S; Silva, M-J; Azevedo, Á; Sampaio-Maia, B

    2017-03-01

    Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined. Pregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log10CFU/mL) increase from the 1st to the 3rd trimester in pregnant women, but not in non-pregnant women. Pregnancy may favour oral yeast growth that may be associated with an acidic oral environment.

  8. CT staging of colon cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dighe, S. [Department of Radiology, Royal Marsden Hospital, Sutton SM5 2TT (United Kingdom); Swift, I. [Department of Surgery, Mayday University Hospital, Croydon CR7 7YE (United Kingdom); Brown, G. [Department of Radiology, Royal Marsden Hospital, Sutton SM5 2TT (United Kingdom)], E-mail: gina.brown@rmh.nhs.uk

    2008-12-15

    Computer tomography (CT) has been the principal investigation in the staging of colon cancers. The information obtained with routine CT has been limited to identifying the site of the tumour, size of the tumour, infiltration into surrounding structures and metastatic spread. The Foxtrot trial National Cancer Research Institute (NCRI) has been specifically designed to evaluate the efficacy of neoadjuvant treatment in colon cancers by using preoperative chemotherapy with or without an anti-Epidermal Growth Factor Receptor (EGFR) monoclonal antibody to improve outcome in high-risk operable colon cancer. Patients are selected based on their staging CT examination. The criteria for poor prognosis are T4 and T3 tumours with more than 5 mm extramural depth. Thus the success of the trial would depend upon the confidence of the radiologist to identify the patients that would receive the neoadjuvant treatment. The aim of this review is to explain the process of identifying high-risk features seen on the staging CT images. This will help to identify a cohort of patients that could truly benefit from neoadjuvant strategies.

  9. CT staging of colon cancer

    International Nuclear Information System (INIS)

    Dighe, S.; Swift, I.; Brown, G.

    2008-01-01

    Computer tomography (CT) has been the principal investigation in the staging of colon cancers. The information obtained with routine CT has been limited to identifying the site of the tumour, size of the tumour, infiltration into surrounding structures and metastatic spread. The Foxtrot trial National Cancer Research Institute (NCRI) has been specifically designed to evaluate the efficacy of neoadjuvant treatment in colon cancers by using preoperative chemotherapy with or without an anti-Epidermal Growth Factor Receptor (EGFR) monoclonal antibody to improve outcome in high-risk operable colon cancer. Patients are selected based on their staging CT examination. The criteria for poor prognosis are T4 and T3 tumours with more than 5 mm extramural depth. Thus the success of the trial would depend upon the confidence of the radiologist to identify the patients that would receive the neoadjuvant treatment. The aim of this review is to explain the process of identifying high-risk features seen on the staging CT images. This will help to identify a cohort of patients that could truly benefit from neoadjuvant strategies

  10. Analysis of gut microbial regulation of host gene expression along the length of the gut and regulation of gut microbial ecology through MyD88.

    Science.gov (United States)

    Larsson, Erik; Tremaroli, Valentina; Lee, Ying Shiuan; Koren, Omry; Nookaew, Intawat; Fricker, Ashwana; Nielsen, Jens; Ley, Ruth E; Bäckhed, Fredrik

    2012-08-01

    The gut microbiota has profound effects on host physiology but local host-microbial interactions in the gut are only poorly characterised and are likely to vary from the sparsely colonised duodenum to the densely colonised colon. Microorganisms are recognised by pattern recognition receptors such as Toll-like receptors, which signal through the adaptor molecule MyD88. To identify host responses induced by gut microbiota along the length of the gut and whether these required MyD88, transcriptional profiles of duodenum, jejunum, ileum and colon were compared from germ-free and conventionally raised wild-type and Myd88-/- mice. The gut microbial ecology was assessed by 454-based pyrosequencing and viruses were analysed by PCR. The gut microbiota modulated the expression of a large set of genes in the small intestine and fewer genes in the colon but surprisingly few microbiota-regulated genes required MyD88 signalling. However, MyD88 was essential for microbiota-induced colonic expression of the antimicrobial genes Reg3β and Reg3γ in the epithelium, and Myd88 deficiency was associated with both a shift in bacterial diversity and a greater proportion of segmented filamentous bacteria in the small intestine. In addition, conventionally raised Myd88-/- mice had increased expression of antiviral genes in the colon, which correlated with norovirus infection in the colonic epithelium. This study provides a detailed description of tissue-specific host transcriptional responses to the normal gut microbiota along the length of the gut and demonstrates that the absence of MyD88 alters gut microbial ecology.

  11. Self-rated driving and driving safety in older adults.

    Science.gov (United States)

    Ross, Lesley A; Dodson, Joan E; Edwards, Jerri D; Ackerman, Michelle L; Ball, Karlene

    2012-09-01

    Many U.S. states rely on older adults to self-regulate their driving and determine when driving is no longer a safe option. However, the relationship of older adults' self-rated driving in terms of actual driving competency outcomes is unclear. The current study investigates self-rated driving in terms of (1) systematic differences between older adults with high (good/excellent) versus low (poor/fair/average) self-ratings, and (2) the predictive nature of self-rated driving to adverse driving outcomes in older adults (n=350; mean age 73.9, SD=5.25, range 65-91). Adverse driving outcomes included self-reported incidences of (1) being pulled over by the police, (2) receiving a citation, (3) receiving a recommendation to cease or limit driving, (4) crashes, and (5) state-reported crashes. Results found that older drivers with low self-ratings reported more medical conditions, less driving frequency, and had been given more suggestions to stop/limit their driving; there were no other significant differences between low and high self-raters. Logistic regression revealed older drivers were more likely to have a state-reported crash and receive a suggestion to stop or limit driving. Men were more likely to report all adverse driving outcomes except for receiving a suggestion to stop or limit driving. Regarding self-rated driving, older adults with high ratings were 66% less likely (OR=0.34, 95% CI=0.14-0.85) to have received suggestions to limit or stop driving after accounting for demographics, health and driving frequency. Self-ratings were not predictive of other driving outcomes (being pulled over by the police, receiving a citation, self-reported crashes, or state-reported crashes, ps>0.05). Most older drivers (85.14%) rated themselves as either good or excellent drivers regardless of their actual previous citation or crash rates. Self-rated driving is likely not related to actual driving proficiency as indicated by previous crash involvement in older adults

  12. Evolution of microbial pathogens

    National Research Council Canada - National Science Library

    DiRita, Victor J; Seifert, H. Steven

    2006-01-01

    ... A. Hogan vvi ■ CONTENTS 8. Evolution of Pathogens in Soil Rachel Muir and Man-Wah Tan / 131 9. Experimental Models of Symbiotic Host-Microbial Relationships: Understanding the Underpinnings of ...

  13. Multitrophic microbial interactions for eco- and agro-biotechnological processes: theory and practice.

    Science.gov (United States)

    Saleem, Muhammad; Moe, Luke A

    2014-10-01

    Multitrophic level microbial loop interactions mediated by protist predators, bacteria, and viruses drive eco- and agro-biotechnological processes such as bioremediation, wastewater treatment, plant growth promotion, and ecosystem functioning. To what extent these microbial interactions are context-dependent in performing biotechnological and ecosystem processes remains largely unstudied. Theory-driven research may advance the understanding of eco-evolutionary processes underlying the patterns and functioning of microbial interactions for successful development of microbe-based biotechnologies for real world applications. This could also be a great avenue to test the validity or limitations of ecology theory for managing diverse microbial resources in an era of altering microbial niches, multitrophic interactions, and microbial diversity loss caused by climate and land use changes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Low Sex Drive in Women

    Science.gov (United States)

    Low sex drive in women Overview Women's sexual desires naturally fluctuate over the years. Highs and lows commonly coincide ... used for mood disorders also can cause low sex drive in women. If your lack of interest ...

  15. Marijuana and actual driving performance

    Science.gov (United States)

    1993-11-01

    This report concerns the effects of marijuana smoking on actual driving performance. It presents the results of one pilot and three actual driving studies. The pilot study's major purpose was to establish the THC dose current marijuana users smoke to...

  16. Distracted Driving Raises Crash Risk

    Science.gov (United States)

    ... this issue Health Capsule Distracted Driving Raises Crash Risk En español Send us your comments Video technology ... distracted driving, especially among new drivers, raises the risk for car crashes and near crashes. The study ...

  17. Synthetic Electric Microbial Biosensors

    Science.gov (United States)

    2017-06-10

    domains and DNA-binding domains into a single protein for deregulation of down stream genes of have been favored [10]. Initially experiments with... Germany DISTRIBUTION A. Approved for public release: distribution unlimited.   Talk title: “Synthetic biology based microbial biosensors for the...toolbox” in Heidelberg, Germany Poster title: “Anaerobic whole cell microbial biosensors” Link: http://phdsymposium.embl.org/#home   September, 2014

  18. A model for bacterial colonization of sinking aggregates.

    Science.gov (United States)

    Bearon, R N

    2007-01-01

    Sinking aggregates provide important nutrient-rich environments for marine bacteria. Quantifying the rate at which motile bacteria colonize such aggregations is important in understanding the microbial loop in the pelagic food web. In this paper, a simple analytical model is presented to predict the rate at which bacteria undergoing a random walk encounter a sinking aggregate. The model incorporates the flow field generated by the sinking aggregate, the swimming behavior of the bacteria, and the interaction of the flow with the swimming behavior. An expression for the encounter rate is computed in the limit of large Péclet number when the random walk can be approximated by a diffusion process. Comparison with an individual-based numerical simulation is also given.

  19. Microbial bioinformatics 2020.

    Science.gov (United States)

    Pallen, Mark J

    2016-09-01

    Microbial bioinformatics in 2020 will remain a vibrant, creative discipline, adding value to the ever-growing flood of new sequence data, while embracing novel technologies and fresh approaches. Databases and search strategies will struggle to cope and manual curation will not be sustainable during the scale-up to the million-microbial-genome era. Microbial taxonomy will have to adapt to a situation in which most microorganisms are discovered and characterised through the analysis of sequences. Genome sequencing will become a routine approach in clinical and research laboratories, with fresh demands for interpretable user-friendly outputs. The "internet of things" will penetrate healthcare systems, so that even a piece of hospital plumbing might have its own IP address that can be integrated with pathogen genome sequences. Microbiome mania will continue, but the tide will turn from molecular barcoding towards metagenomics. Crowd-sourced analyses will collide with cloud computing, but eternal vigilance will be the price of preventing the misinterpretation and overselling of microbial sequence data. Output from hand-held sequencers will be analysed on mobile devices. Open-source training materials will address the need for the development of a skilled labour force. As we boldly go into the third decade of the twenty-first century, microbial sequence space will remain the final frontier! © 2016 The Author. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  20. Dietary flaxseed modulates the colonic microenvironment in healthy C57Bl/6 male mice which may alter susceptibility to gut-associated diseases.

    Science.gov (United States)

    Power, Krista A; Lepp, Dion; Zarepoor, Leila; Monk, Jennifer M; Wu, Wenqing; Tsao, Rong; Liu, Ronghua

    2016-02-01

    Understanding how dietary components alter the healthy baseline colonic microenvironment is important in determining their roles in influencing gut health and gut-associated diseases. Dietary flaxseed (FS) has demonstrated anti-colon cancer effects in numerous rodent models, however, exacerbated acute colonic mucosal injury and inflammation in a colitis model. This study investigates whether FS alters critical aspects of gut health in healthy unchallenged mice, which may help explain some of the divergent effects observed following different gut-associated disease challenges. Four-week-old C57Bl/6 male mice were fed an AIN-93G basal diet (BD) or an isocaloric BD+10% ground FS diet for 3 weeks. FS enhanced colon goblet cell density, mucus production, MUC2 mRNA expression, and cecal short chain fatty acid levels, indicative of beneficial intestinal barrier integrity responses. Additionally, FS enhanced colonic regenerating islet-derived protein 3 gamma (RegIIIγ) and reduced MUC1 and resistin-like molecule beta (RELMβ) mRNA expression which may indicate altered responses in regulating microbial defense and injury repair responses. FS diet altered the fecal microbial community structure (16S rRNA gene profiling), including a 20-fold increase in Prevotella spp. and a 30-fold reduction in Akkermansia muciniphila abundance. A 10-fold reduction in A. muciniphila abundance by FS was also demonstrated in the colon tissue-associated microbiota (quantitative PCR). Furthermore, fecal branched chain fatty acids were increased by FS, indicative of increased microbial-derived putrefactive compounds. In conclusion, consumption of a FS-supplemented diet alters the baseline colonic microenvironment of healthy mice which may modify subsequent mucosal microbial defense and injury-repair responses leading to altered susceptibility to different gut-associated diseases. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  1. Microbial deterioration of Mayan stone buildings at Uxmal, Yucatan, Mexico

    International Nuclear Information System (INIS)

    Ortega-Morales, O.; Guezennec, J.; Hernandez D, G.; Jozsa, P.; Sand, W.; Crassous, P.

    1998-01-01

    The microbial communities associated to Uxmal Mayan monuments (Yucatan, Mexico) and their role in stone deterioration were preliminary characterized by chemical, biochemical, microbiological, microscopical and surface analysis methods under two climatic seasons (1997). The organic matter and organic carbon and nitrogen were in the range of those reported for other stone buildings, indicating that oligo trophic conditions prevail at Uxmal. Quantitative differences in microbial biomass was higher at indoor section were the organic matter content was the highest and micro-environmental conditions (availability of water and protection to direct sunlight) are more suitable for microbial growth. The microbiological analysis underestimated the microbial biomass, as revealed by biochemical approaches. Nitrate and nitrite-oxidizing, metilotrophic and heterotrophic bacteria and fungi were detected in most surfaces. The heterotrophic bacteria were the most abundant microbial group (microbiological data). However, the chlorophyll profiles and Scanning Electron Microscopy showed that the microalgae are the most abundant colonizers in Uxmal stone buildings. EDAX analysis showed that the most surfaces were covered by an organic layer (cells and exo polymers). Gypsum was found in few samples. The large photo trophic biomass seems to play a role in stone bio deterioration by supporting growth of heterotrophic microorganisms (bacteria and fungi) which are known to produce organic acids leading to calcite dissolution and cations chelation. Further studies are being carried out in order to determine the role of exo polysaccharides which are thought to play a role in chemical degradation of limestone substrates in Uxmal. (Author)

  2. A novel dissolution media for testing drug release from a nanostructured polysaccharide-based colon specific drug delivery system: an approach to alternative colon media.

    Science.gov (United States)

    Kotla, Niranjan G; Singh, Sima; Maddiboyina, Balaji; Sunnapu, Omprakash; Webster, Thomas J

    2016-01-01

    The aim of this study was to develop a novel microbially triggered and animal-sparing dissolution method for testing of nanorough polysaccharide-based micron granules for colonic drug delivery. In this method, probiotic cultures of bacteria present in the colonic region were prepared and added to the dissolution media and compared with the performance of conventional dissolution methodologies (such as media with rat cecal and human fecal media). In this study, the predominant species (such as Bacteroides, Bifidobacterium, Lactobacillus species, Eubacterium and Streptococcus) were cultured in 12% w/v skimmed milk powder and 5% w/v grade "A" honey. Approximately 10(10)-10(11) colony forming units m/L of probiotic culture was added to the dissolution media to test the drug release of polysaccharide-based formulations. A USP dissolution apparatus I/II using a gradient pH dissolution method was used to evaluate drug release from formulations meant for colonic drug delivery. Drug release of guar gum/Eudragit FS30D coated 5-fluorouracil granules was assessed under gastric and small intestine conditions within a simulated colonic environment involving fermentation testing with the probiotic culture. The results with the probiotic system were comparable to those obtained from the rat cecal and human fecal-based fermentation model, thereby suggesting that a probiotic dissolution method can be successfully applied for drug release testing of any polysaccharide-based oral formulation meant for colonic delivery. As such, this study significantly adds to the nanostructured biomaterials' community by elucidating an easier assay for colonic drug delivery.

  3. Modeling adaptation of carbon use efficiency in microbial communities

    Directory of Open Access Journals (Sweden)

    Steven D Allison

    2014-10-01

    Full Text Available In new microbial-biogeochemical models, microbial carbon use efficiency (CUE is often assumed to decline with increasing temperature. Under this assumption, soil carbon losses under warming are small because microbial biomass declines. Yet there is also empirical evidence that CUE may adapt (i.e. become less sensitive to warming, thereby mitigating negative effects on microbial biomass. To analyze potential mechanisms of CUE adaptation, I used two theoretical models to implement a tradeoff between microbial uptake rate and CUE. This rate-yield tradeoff is based on thermodynamic principles and suggests that microbes with greater investment in resource acquisition should have lower CUE. Microbial communities or individuals could adapt to warming by reducing investment in enzymes and uptake machinery. Consistent with this idea, a simple analytical model predicted that adaptation can offset 50% of the warming-induced decline in CUE. To assess the ecosystem implications of the rate-yield tradeoff, I quantified CUE adaptation in a spatially-structured simulation model with 100 microbial taxa and 12 soil carbon substrates. This model predicted much lower CUE adaptation, likely due to additional physiological and ecological constraints on microbes. In particular, specific resource acquisition traits are needed to maintain stoichiometric balance, and taxa with high CUE and low enzyme investment rely on low-yield, high-enzyme neighbors to catalyze substrate degradation. In contrast to published microbial models, simulations with greater CUE adaptation also showed greater carbon storage under warming. This pattern occurred because microbial communities with stronger CUE adaptation produced fewer degradative enzymes, despite increases in biomass. Thus the rate-yield tradeoff prevents CUE adaptation from driving ecosystem carbon loss under climate warming.

  4. Nuclear refueling platform drive system

    International Nuclear Information System (INIS)

    Busch, F.R.; Faulstich, D.L.

    1992-01-01

    This patent describes a drive system. It comprises: a gantry including a bridge having longitudinal and transverse axes and supported by spaced first and second end frames joined to fist and second end frames joined to first and second drive trucks for moving the bridge along the transverse axis; first means for driving the first drive truck; second means for driving the second drive truck being independent from the first driving means; and means for controlling the first and second driving means for reducing differential transverse travel between the first and second drive trucks, due to a skewing torque acting on the bridge, to less than a predetermined maximum, the controlling means being in the form of an electrical central processing unit and including: a closed-loop first velocity control means for controlling velocity of the first drive truck by providing a first command signal to the first driver means; a close loop second velocity control means for controlling velocity of the second drive truck by providing a second command signal to the second driving means; and an auxiliary closed-loop travel control means

  5. Microbial Activity and Silica Degradation in Rice Straw

    Science.gov (United States)

    Kim, Esther Jin-kyung

    Abundantly available agricultural residues like rice straw have the potential to be feedstocks for bioethanol production. Developing optimized conditions for rice straw deconstruction is a key step toward utilizing the biomass to its full potential. One challenge associated with conversion of rice straw to bioenergy is its high silica content as high silica erodes machinery. Another obstacle is the availability of enzymes that hydrolyze polymers in rice straw under industrially relevant conditions. Microbial communities that colonize compost may be a source of enzymes for bioconversion of lignocellulose to products because composting systems operate under thermophilic and high solids conditions that have been shown to be commercially relevant. Compost microbial communities enriched on rice straw could provide insight into a more targeted source of enzymes for the breakdown of rice straw polysaccharides and silica. Because rice straw is low in nitrogen it is important to understand the impact of nitrogen concentrations on the production of enzyme activity by the microbial community. This study aims to address this issue by developing a method to measure microbial silica-degrading activity and measure the effect of nitrogen amendment to rice straw on microbial activity and extracted enzyme activity during a high-solids, thermophilic incubation. An assay was developed to measure silica-degrading enzyme or silicase activity. This process included identifying methods of enzyme extraction from rice straw, identifying a model substrate for the assay, and optimizing measurement techniques. Rice straw incubations were conducted with five different levels of nitrogen added to the biomass. Microbial activity was measured by respiration and enzyme activity. A microbial community analysis was performed to understand the shift in community structure with different treatments. With increased levels of nitrogen, respiration and cellulose and hemicellulose degrading activity

  6. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  7. Contrasting effects of biochar versus manure on soil microbial communities and enzyme activities in an Aridisol.

    Science.gov (United States)

    Elzobair, Khalid A; Stromberger, Mary E; Ippolito, James A; Lentz, Rodrick D

    2016-01-01

    Biochar can increase microbial activity, alter microbial community structure, and increase soil fertility in arid and semi-arid soils, but at relatively high rates that may be impractical for large-scale field studies. This contrasts with organic amendments such as manure, which can be abundant and inexpensive if locally available, and thus can be applied to fields at greater rates than biochar. In a field study comparing biochar and manure, a fast pyrolysis hardwood biochar (22.4 Mg ha(-1)), dairy manure (42 Mg ha(-1) dry wt), a combination of biochar and manure at the aforementioned rates, or no amendment (control) was applied to an Aridisol (n=3) in fall 2008. Plots were annually cropped to corn (Zea maize L.). Surface soils (0-30 cm) were sampled directly under corn plants in late June 2009 and early August 2012, and assayed for microbial community fatty acid methyl ester (FAME) profiles and six extracellular enzyme activities involved in soil C, N, and P cycling. Arbuscular mycorrhizal (AM) fungal colonization was assayed in corn roots in 2012. Biochar had no effect on microbial biomass, community structure, extracellular enzyme activities, or AM fungi root colonization of corn. In the short-term, manure amendment increased microbial biomass, altered microbial community structure, and significantly reduced the relative concentration of the AM fungal biomass in soil. Manure also reduced the percent root colonization of corn by AM fungi in the longer-term. Thus, biochar and manure had contrasting short-term effects on soil microbial communities, perhaps because of the relatively low application rate of biochar. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Electrical machines and drives

    CERN Document Server

    Hindmarsh, John

    2002-01-01

    Recent years have brought substantial developments in electrical drive technology, with the appearance of highly rated, very-high-speed power-electronic switches, combined with microcomputer control systems.This popular textbook has been thoroughly revised and updated in the light of these changes. It retains its successful formula of teaching through worked examples, which are put in context with concise explanations of theory, revision of equations and discussion of the engineering implications. Numerous problems are also provided, with answers supplied.The third edition in

  9. Electrical machines & drives

    CERN Document Server

    Hammond, P

    1985-01-01

    Containing approximately 200 problems (100 worked), the text covers a wide range of topics concerning electrical machines, placing particular emphasis upon electrical-machine drive applications. The theory is concisely reviewed and focuses on features common to all machine types. The problems are arranged in order of increasing levels of complexity and discussions of the solutions are included where appropriate to illustrate the engineering implications. This second edition includes an important new chapter on mathematical and computer simulation of machine systems and revised discussions o

  10. Measurement of Driving Terms

    CERN Document Server

    Schmidt, F; Faus-Golfe, A

    2001-01-01

    In 2000 a series of MDs has been performed at the SPS to measure resonance driving terms. Theory predicts that these terms can be determined by harmonic analysis of BPM data recorded after applying single kicks at various amplitudes. Strong sextupoles were introduced to create a sizeable amount of nonlinearities. Experiments at injection energy (26 GeV) with single bunch as well as one experiment at 120 GeV with 84 bunches were carried out. The expected nonlinear content is compared to the experimenteal observation.

  11. Cell proliferation and ageing in mouse colon

    International Nuclear Information System (INIS)

    Hamilton, E.; Franks, L.M.

    1980-01-01

    Cell kinetic parameters in the descending colon of unirradiated mice, 3-30-months-old were compared with those in mice irradiated repeatedly from the age of 6 or 24 months. The latter animals were given 1250 rad local X-irradiation to the colon every 6 weeks. Dose-survival curves showed the colon crypts of 6 and 24-months-old mice were similarly radiosensitive. In unirradiated mice the number of crypts per colon section decreased significantly at 30 months, but no significant age-related changes were seen in crypt size or labelling index (LI). Cell proliferation returned to control levels within 6 weeks of each X-ray dose and remained at this level for 20 weeks after the final dose. Later, cell proliferation in the irradiated colon fell significantly below control. A total of 6 or 7 doses each of 1250 rad produced only 1 colon carcinoma amongst 50 mice kept until they died. (author)

  12. Historical and Current Trends in Colon Trauma

    Science.gov (United States)

    Causey, Marlin Wayne; Rivadeneira, David E.; Steele, Scott R.

    2012-01-01

    The authors discuss the evolution of the evaluation and management of colonic trauma, as well as the debate regarding primary repair versus fecal diversion. Their evidence-based review covers diagnosis, management, surgical approaches, and perioperative care of patients with colon-related trauma. The management of traumatic colon injuries has evolved significantly over the past 50 years; here the authors describe a practical approach to the treatment and management of traumatic injuries to the colon based on the most current research. However, management of traumatic colon injuries remains a challenge and continues to be associated with significant morbidity. Familiarity with the different methods to the approach and management of colonic injuries will allow surgeons to minimize unnecessary complications and mortality. PMID:24294119

  13. Complications of acromegaly: thyroid and colon.

    Science.gov (United States)

    Tirosh, Amit; Shimon, Ilan

    2017-02-01

    In acromegaly the long-term exposure to high growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels may result in specific complications in different human organs, including the thyroid gland and the colon. We will review here the evidence available regarding the characteristic thyroid and colon complications in acromegaly. This review summarizes the published data observing noncancerous structural abnormalities (thyroid nodules, colonic polyps) and thyroid and colon cancer in patients diagnosed with acromegaly. Thyroid micro-carcinomas are probably over-diagnosed among acromegalic patients. In regard to colon cancer, there is no sufficient data to suggest that colon cancer risk is higher in acromegaly compared to the general population.

  14. Image diagnostic of colonic diseases - controversial questions

    International Nuclear Information System (INIS)

    Pomakov, P.; Rizov, A.; Stancheva, I.

    2013-01-01

    In the system of colonic diseases' diagnostic algorithm, fibrocolonoscopy (FCS) is defined as 'Golden Standard'. By this reason some X-ray diagnostic methods - irrigography, etc. are currently not being used in a number of health institutions. The aim of this study is a comparative analysis of FCS and irrigography diagnostic efficacy in various colonic diseases. For 10-years period, in cooperation with a gastroenterologist-gastroscopist, 2151 patients with various colonic diseases were evaluated by FCS and irrigography with pharmaco-diagnostics/when necessary. Advantage of FCS was established in diagnosing diseases with patho-morfologic changes on the inner surface of the colon - benign and malignant neoplastic processes, chronic inflammatory diseases, etc. At the same time functional changes - irritated colon syndrome, changes in defecation act, etc., are not an object of diagnosis through FCS. Correction in colonic diseases diagnostic algorithm is necessary. FCS should be mandatory. If result is negative - irrigography with pharmaco-diagnostics should be done. (authors)

  15. Abundance of Enterobacteriaceae in the colon mucosa in diverticular disease.

    Science.gov (United States)

    Linninge, Caroline; Roth, Bodil; Erlanson-Albertsson, Charlotte; Molin, Göran; Toth, Ervin; Ohlsson, Bodil

    2018-02-15

    To compare gut bacterial diversity and amount of Enterobacteriaceae in colonic mucosa between patients with and without diverticular disease (DD). Patients in a stable clinical condition with planned elective colonoscopy were included. Blood samples and colon mucosa biopsies were collected at the colonoscopy. Study questionnaires including questions about gastrointestinal symptoms were completed by the patients and physicians. DNA from mucosa samples was isolated and the amount of Enterobacteriaceae was estimated using PCR assay. Terminal restriction fragment length polymorphism was applied to assess microbial diversity. Diversity was estimated by calculations of richness (number of terminal restriction fragments) and Shannon-Wiener and Simpson's indices. A total of 51 patients were included, 16 patients with DD [68 (62-76) years] and 35 controls [62 (40-74) years] without any diverticula. Patients with DD had significantly higher levels of Enterobacteriaceae than those without DD ( P = 0.043), and there was an inverse relationship between the amount of Enterobacteriaceae and the Simpson's index (rs = -0.361, P = 0.033) and the Shannon-Wiener index (rs = -0.299, P = 0.081). The Simpson's index ( P = 0.383), Shannon-Wiener index ( P = 0.401) or number of restrictions fragments ( P = 0.776) did not differ between DD and controls. The majority of patients experienced gastrointestinal symptoms, and 22 patients (43.1%) fulfilled the criteria for irritable bowel syndrome, with no difference between the groups ( P = 0.212). Demography, socioeconomic status, lifestyle habits, inflammatory biomarkers, or symptoms were not related to the amount of Enterobacteriaceae or bacterial diversity. Patients with DD had higher amount of Enterobacteriaceae in the colon mucosa compared to patients without diverticula.

  16. Deep subsurface microbial processes

    Science.gov (United States)

    Lovley, D.R.; Chapelle, F.H.

    1995-01-01

    Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

  17. Local and distal effects of arbuscular mycorrhizal colonization on direct pathway Pi uptake and root growth in Medicago truncatula

    Science.gov (United States)

    Watts-Williams, Stephanie J.; Jakobsen, Iver; Cavagnaro, Timothy R.; Grønlund, Mette

    2015-01-01

    Two pathways exist for plant Pi uptake from soil: via root epidermal cells (direct pathway) or via associations with arbuscular mycorrhizal (AM) fungi, and the two pathways interact in a complex manner. This study investigated distal and local effects of AM colonization on direct root Pi uptake and root growth, at different soil P levels. Medicago truncatula was grown at three soil P levels in split-pots with or without AM fungal inoculation and where one root half grew into soil labelled with 33P. Plant genotypes included the A17 wild type and the mtpt4 mutant. The mtpt4 mutant, colonized by AM fungi, but with no functional mycorrhizal pathway for Pi uptake, was included to better understand effects of AM colonization per se. Colonization by AM fungi decreased expression of direct Pi transporter genes locally, but not distally in the wild type. In mtpt4 mutant plants, direct Pi transporter genes and the Pi starvation-induced gene Mt4 were more highly expressed than in wild-type roots. In wild-type plants, less Pi was taken up via the direct pathway by non-colonized roots when the other root half was colonized by AM fungi, compared with non-mycorrhizal plants. Colonization by AM fungi strongly influenced root growth locally and distally, and direct root Pi uptake activity locally, but had only a weak influence on distal direct pathway activity. The responses to AM colonization in the mtpt4 mutant suggested that in the wild type, the increased P concentration of colonized roots was a major factor driving the effects of AM colonization on direct root Pi uptake. PMID:25944927

  18. Cognitive impairment and driving safety.

    Science.gov (United States)

    Eby, David W; Molnar, Lisa J

    2012-11-01

    As the populations of many countries continue to age, cognitive impairment will likely become more common. Individuals with cognitive impairment pose special challenges for families, health professionals, driving safety professionals, and the larger community, particularly if these older adults depend on driving as their primary means of community mobility. It is vital that we continue to extend our knowledge about the driving behavior of individuals' with cognitive impairment, as well as try to develop effective means of screening and assessing these individuals for fitness to drive and help facilitate their transition to non-driving when appropriate. This special issue is intended to provide researchers and practitioners an opportunity to present the most recent research findings on driving-related issues among older adults with cognitive impairment. The issue contains 11 original contributions from seven countries. The topics covered by these papers are: crash risks; screening, assessment, and fitness to drive; driving performance using a driving simulator; and driving behaviors and driving-related decisions of people with cognitive impairments. Copyright © 2012. Published by Elsevier Ltd.

  19. Parkinson's disease and driving ability

    Science.gov (United States)

    Singh, Rajiv; Pentland, Brian; Hunter, John; Provan, Frances

    2007-01-01

    Objectives To explore the driving problems associated with Parkinson's disease (PD) and to ascertain whether any clinical features or tests predict driver safety. Methods The driving ability of 154 individuals with PD referred to a driving assessment centre was determined by a combination of clinical tests, reaction times on a test rig and an in‐car driving test. Results The majority of cases (104, 66%) were able to continue driving although 46 individuals required an automatic transmission and 10 others needed car modifications. Ability to drive was predicted by the severity of physical disease, age, presence of other associated medical conditions, particularly dementia, duration of disease, brake reaction, time on a test rig and score on a driving test (all pautomatic transmission. A combination of clinical tests and in‐car driving assessment will establish safety to drive, and a number of clinical correlates can be shown to predict the likely outcome and may assist in the decision process. This is the largest series of consecutive patients seen at a driving assessment centre reported to date, and the first to devise a scoring system for on‐road driving assessment. PMID:17178820

  20. Historical and Current Trends in Colon Trauma

    OpenAIRE

    Causey, Marlin Wayne; Rivadeneira, David E.; Steele, Scott R.

    2012-01-01

    The authors discuss the evolution of the evaluation and management of colonic trauma, as well as the debate regarding primary repair versus fecal diversion. Their evidence-based review covers diagnosis, management, surgical approaches, and perioperative care of patients with colon-related trauma. The management of traumatic colon injuries has evolved significantly over the past 50 years; here the authors describe a practical approach to the treatment and management of traumatic injuries to th...

  1. Perforated Solitary Diverticulitis of the Ascending Colon

    Science.gov (United States)

    2005-06-01

    postoperative day 6. DISCUSSION Diverticuli of the right colon exist in approximately 1% to 5% of patients with diverticular disease .1-3 They are...ORIGINAL REPORTS Perforated Solitary Diverticulitis of the Ascending Colon CPT David S. Kauvar, MC, USA, MAJ, Jayson Aydelotte, MC, USA, and MAJ...Michael Harnisch, MC, USA Department of Surgery, Brooke Army Medical Center, Fort Sam Houston, Texas KEY WORDS: solitary colon diverticulum

  2. Volvulus of the Small Bowel and Colon

    Science.gov (United States)

    Kapadia, Muneera R.

    2017-01-01

    Volvulus of the intestines may involve either the small bowel or colon. In the pediatric population, small bowel volvulus is more common, while in the adult population, colonic volvulus is more often seen. The two most common types of colonic volvulus include sigmoid and cecal volvulus. Prompt diagnosis and treatment is imperative, otherwise bowel ischemia may ensue. Treatment often involves emergent surgical exploration and bowel resection. PMID:28144211

  3. Exocellular electron transfer in anaerobic microbial communities.

    Science.gov (United States)

    Stams, Alfons J M; de Bok, Frank A M; Plugge, Caroline M; van Eekert, Miriam H A; Dolfing, Jan; Schraa, Gosse

    2006-03-01

    Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory syntrophic consortia of proton-reducing acetogenic bacteria and hydrogen-consuming methanogenic archaea. Anaerobic microorganisms that use insoluble electron acceptors for growth, such as iron- and manganese-oxide as well as inert graphite electrodes in microbial fuel cells, also transfer electrons exocellularly. Soluble compounds, like humic substances, quinones, phenazines and riboflavin, can function as exocellular electron mediators enhancing this type of anaerobic respiration. However, direct electron transfer by cell-cell contact is important as well. This review addresses the mechanisms of exocellular electron transfer in anaerobic microbial communities. There are fundamental differences but also similarities between electron transfer to another microorganism or to an insoluble electron acceptor. The physical separation of the electron donor and electron acceptor metabolism allows energy conservation in compounds as methane and hydrogen or as electricity. Furthermore, this separation is essential in the donation or acceptance of electrons in some environmental technological processes, e.g. soil remediation, wastewater purification and corrosion.

  4. Microscale Insight into Microbial Seed Banks.

    Science.gov (United States)

    Locey, Kenneth J; Fisk, Melany C; Lennon, J T

    2016-01-01

    Microbial dormancy leads to the emergence of seed banks in environmental, engineered, and host-associated ecosystems. These seed banks act as reservoirs of diversity that allow microbes to persist under adverse conditions, including extreme limitation of resources. While microbial seed banks may be influenced by macroscale factors, such as the supply of resources, the importance of microscale encounters between organisms and resource particles is often overlooked. We hypothesized that dimensions of spatial, trophic, and resource complexity determine rates of encounter, which in turn, drive the abundance, productivity, and size of seed banks. We tested this using >10,000 stochastic individual based models (IBMs) that simulated energetic, physiological, and ecological processes across combinations of resource, spatial, and trophic complexity. These IBMs allowed realistic dynamics and the emergence of seed banks from ecological selection on random variation in species traits. Macroscale factors like the supply and concentration of resources had little effect on resource encounter rates. In contrast, encounter rates were strongly influenced by interactions between dispersal mode and spatial structure, and also by the recalcitrance of resources. In turn, encounter rates drove abundance, productivity, and seed bank dynamics. Time series revealed that energetically costly traits can lead to large seed banks and that recalcitrant resources can lead to greater stability through the formation of seed banks and the slow consumption of resources. Our findings suggest that microbial seed banks emerge from microscale dimensions of ecological complexity and their influence on resource limitation and energetic costs.

  5. Glaucoma and Driving: On-Road Driving Characteristics

    Science.gov (United States)

    Wood, Joanne M.; Black, Alex A.; Mallon, Kerry; Thomas, Ravi; Owsley, Cynthia

    2016-01-01

    Purpose To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment. Methods Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire. Results Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability. Conclusions Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness. PMID:27472221

  6. A qualitative exploration of driving stress and driving discourtesy.

    Science.gov (United States)

    Scott-Parker, B; Jones, C M; Rune, K; Tucker, J

    2018-05-31

    Driving courtesy, and conversely driving discourtesy, recently has been of great interest in the public domain. In addition, there has been increasing recognition of the negative impact of stress upon the individual's health and wellbeing, with a plethora of interventions aimed at minimising stress more generally. The research literature regarding driving dis/courtesy, in comparison, is scant, with a handful of studies examining the dis/courteous driving behaviour of road users, and the relationship between driving discourtesy and driving stress. To examine courteous and discourteous driving experiences, and to explore the impact of stress associated with such driving experiences. Thirty-eight drivers (20 females) from the Sunshine Coast region volunteered to participate in one of four 1-1.5 h focus groups. Content analysis used the verbatim utterances captured via an Mp3 device. Three themes pertaining to stressful and discourteous interactions were identified. Theme one pertained to the driving context: road infrastructure (eg, roundabouts, roadwork), vehicles (eg, features), location (eg, country vs city, unfamiliar areas), and temporal aspects (eg, holidays). Theme two pertained to other road users: their behaviour (eg, tailgating, merging), and unknown factors (eg, illicit and licit drug use). Theme three pertained to the self as road user: their own behaviours (eg, deliberate intimidation), and their emotions (eg, angry reaction to other drivers, being in control). Driving dis/courtesy and driving stress is a complex phenomenon, suggesting complex intervention efforts are required. Driving discourtesy was reported as being highly stressful, therefore intervention efforts which encourage driving courtesy and which foster emotional capacity to cope with stressful circumstances appear warranted. Copyright © 2018. Published by Elsevier Ltd.

  7. Glaucoma and Driving: On-Road Driving Characteristics.

    Directory of Open Access Journals (Sweden)

    Joanne M Wood

    Full Text Available To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment.Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years. On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire.Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability.Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness.

  8. Glaucoma and Driving: On-Road Driving Characteristics.

    Science.gov (United States)

    Wood, Joanne M; Black, Alex A; Mallon, Kerry; Thomas, Ravi; Owsley, Cynthia

    2016-01-01

    To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment. Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire. Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability. Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness.

  9. Control rod drives

    International Nuclear Information System (INIS)

    Hayakawa, Hiroyasu; Kawamura, Atsuo.

    1979-01-01

    Purpose: To reduce pellet-clad mechanical interactions, as well as improve the fuel safety. Constitution: In the rod drive of a bwr type reactor, an electric motor operated upon intermittent input such as of pulse signals is connected to a control rod. A resolver for converting the rotational angle of the motor to electric signals is connected to the rotational shaft of the motor and the phase difference between the output signal from the resolver and a reference signal is adapted to detect by a comparator. Based on the detection result, the controller is actuated to control a motor for control rod drive so that fine control for the movement of the control rod is made possible. This can reduce the moving distance of the control rod, decrease the thermal stress applied to the control rod and decrease the pellet clad mechanical interaction failures due to thermal expansion between the cladding tube and the pellets caused by abrupt changes in the generated power. (Furukawa, Y.)

  10. Control rod drives

    International Nuclear Information System (INIS)

    Oonuki, Koji.

    1981-01-01

    Purpose: To increase the driving speed of control rods at rapid insertion with an elongate control rod and an extension pipe while ensuring sufficient buffering performance in a short buffering distance, by providing a plurality of buffers to an extension pipe between a control rod drive source and a control rod in LMFBR type reactor. Constitution: First, second and third buffers are respectively provided to an acceleration piston, an extension pipe and a control rod respectively and the insertion positions for each of the buffers are displaced orderly from above to below. Upon disconnection of energizing current for an electromagnet, the acceleration piston, the extension pipe and the control rod are rapidly inserted in one body. The first, second and third buffers are respectively actuated at each of their falling strokes upon rapid insertion respectively, and the acceleration piston, the extension pipe and the control rod receive the deceleration effect in the order correspondingly. Although the compression force is applied to the control rod only near the stroke end, it does not cause deformation. (Kawakami, Y.)

  11. Sigmoid colon vaginoplasty in children.

    Science.gov (United States)

    Ekinci, S; Karnak, I; Ciftci, A O; Senocak, M E; Tanyel, F C; Büyükpamukçu, N

    2006-06-01

    Vaginal construction is necessary for the patients with aplasia of Mullerian ducts, testicular feminisation and androgen insensitivity syndromes. Many methods of vaginal construction have been described. We report here the outcomes of six adolescent patients who underwent sigmoid colon vaginoplasty with special emphasis on the surgical technique and outcomes. Between 1990 and 2003, six patients underwent sigmoid vaginoplasty after a diagnosis of 5alpha-reductase deficiency (n = 3), testicular feminisation (n = 2) or vaginal atresia (n = 1). The mean age was 16 years (13 to 18). Wide spectrum antibiotics and whole-gut preparation were used in all cases. A 15-20 cm segment of sigmoid colon was pulled through the retrovesical tunnel. The proximal end was closed in two layers in patients with 5alpha-reductase deficiency and with testicular feminisation. A distal anastomosis was carried out to the opening made on the vaginal plate (5alpha-reductase deficiency) or on the tip of the shallow rudimentary vagina (testicular feminisation). The sigmoid segment was interposed between the blind end of the atretic vagina and the perineum in the patient with vaginal atresia. Patients were instructed to perform daily vaginal irrigation. The neovagina was examined and calibrated under anaesthesia. No routine vaginal dilatation was recommended. All but one patient had an uneventful postoperative period and were discharged within 7-8 days. All patients had an excellent cosmetic result with an appropriate vaginal length. One of the patients experienced late stenosis of the introitus which responded to dilatations. Mucus discharge was not a significant problem. The patient with vaginal atresia (Bardet-Biedl syndrome) experienced deep vein thrombosis, renal failure and sepsis, resulting in death. Sigmoid colon vaginoplasty is a special procedure which appears appropriate for the construction of a new vagina in children. A sigmoid colon neovagina meets all necessary criteria after a

  12. Colonic diseases: The value of US examination

    International Nuclear Information System (INIS)

    Hollerweger, Alois

    2007-01-01

    The colon is affected by a number of diseases, mainly inflammatory, ischemic, and neoplastic conditions. Depending upon clinical indications endoscopy, US, CT, or other radiological methods are used for evaluation. The fact that US is frequently used as the initial imaging method in patients with non-specific clinical symptoms allows for greater influence in further diagnostic evaluation and with treatment, provided the investigator is familiar with the features of different intestinal diseases. This article will describe the anatomical characteristics of the colon, the US technique for examination of the colon, and the typical US features of the more common diagnoses of the colon

  13. Muscarinic Receptor Signaling in Colon Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rosenvinge, Erik C. von, E-mail: evonrose@medicine.umaryland.edu; Raufman, Jean-Pierre [University of Maryland School of Medicine, Division of Gastroenterology & Hepatology, 22 S. Greene Street, N3W62, Baltimore, MD 21201 (United States); Department of Veterans Affairs, VA Maryland Health Care System, 10 North Greene Street, Baltimore, MD 21201 (United States)

    2011-03-02

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  14. Muscarinic Receptor Signaling in Colon Cancer

    International Nuclear Information System (INIS)

    Rosenvinge, Erik C. von; Raufman, Jean-Pierre

    2011-01-01

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer

  15. Muscarinic Receptor Signaling in Colon Cancer

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Raufman

    2011-03-01

    Full Text Available According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  16. Microbial conversion technologies

    Energy Technology Data Exchange (ETDEWEB)

    Lau, P. [National Research Council of Canada, Ottawa, ON (Canada). Bioconversion and Sustainable Development

    2006-07-01

    Microbes are a biomass and an valuable resource. This presentation discussed microbial conversion technologies along with background information on microbial cells, their characteristics and microbial diversity. Untapped opportunities for microbial conversion were identified. Metagenomic and genome mining approaches were also discussed, as they can provide access to uncultivated or unculturable microorganisms in communal populations and are an unlimited resource for biocatalysts, novel genes and metabolites. Genome mining was seen as an economical approach. The presentation also emphasized that the development of microbial biorefineries would require significant insights into the relevant microorganisms and that biocatalysts were the ultimate in sustainability. In addition, the presentation discussed the natural fibres initiative for biochemicals and biomaterials. Anticipated outputs were identified and work in progress of a new enzyme-retting cocktail to provide diversity and/or consistency in fibre characteristics for various applications were also presented. It was concluded that it is necessary to leverage understanding of biological processes to produce bioproducts in a clean and sustainable manner. tabs., figs.

  17. Microbial Induction of Immunity, Inflammation And Cancer

    Directory of Open Access Journals (Sweden)

    Stephen John O'Keefe

    2011-01-01

    Full Text Available The human microbiota presents a highly active metabolic that influences the state of health of our gastrointestinal tracts as well as our susceptibility to disease. Although much of our initial microbiota is adopted from our mothers, its final composition and diversity is determined by environmental factors. Westernization has significantly altered our microbial function. Extensive experimental and clinical evidence indicates that the westernized diet, rich in animal products and low in complex carbohydrates, plus the overuse of antibiotics and underuse of breastfeeding, leads to a heightened inflammatory potential of the microbiota. Chronic inflammation leads to the expression of certain diseases in genetically predisposed individuals. Antibiotics and a ‘clean’ environment, termed the ‘hygiene hypothesis’, has been linked to the rise in allergy and inflammatory bowel disease, due to impaired beneficial bacterial exposure and education of the gut immune system, which comprises the largest immune organ within the body. The elevated risk of colon cancer is associated with the suppression of microbial fermentation and butyrate production, as butyrate provides fuel for the mucosa and is anti-inflammatory and anti-proliferative. This article will summarize the work to date highlighting the complicated and dynamic relationship between the gut microbiota and immunity, inflammation and carcinogenesis.

  18. In vitro continuous fermentation model (PolyFermS) of the swine proximal colon for simultaneous testing on the same gut microbiota.

    Science.gov (United States)

    Tanner, Sabine A; Zihler Berner, Annina; Rigozzi, Eugenia; Grattepanche, Franck; Chassard, Christophe; Lacroix, Christophe

    2014-01-01

    In vitro gut modeling provides a useful platform for a fast and reproducible assessment of treatment-related changes. Currently, pig intestinal fermentation models are mainly batch models with important inherent limitations. In this study we developed a novel in vitro continuous fermentation model, mimicking the porcine proximal colon, which we validated during 54 days of fermentation. This model, based on our recent PolyFermS design, allows comparing different treatment effects on the same microbiota. It is composed of a first-stage inoculum reactor seeded with immobilized fecal swine microbiota and used to constantly inoculate (10% v/v) five second-stage reactors, with all reactors fed with fresh nutritive chyme medium and set to mimic the swine proximal colon. Reactor effluents were analyzed for metabolite concentrations and bacterial composition by HPLC and quantitative PCR, and microbial diversity was assessed by 454 pyrosequencing. The novel PolyFermS featured stable microbial composition, diversity and metabolite production, consistent with bacterial activity reported for swine proximal colon in vivo. The constant inoculation provided by the inoculum reactor generated reproducible microbial ecosystems in all second-stage reactors, allowing the simultaneous investigation and direct comparison of different treatments on the same porcine gut microbiota. Our data demonstrate the unique features of this novel PolyFermS design for the swine proximal colon. The model provides a tool for efficient, reproducible and cost-effective screening of environmental factors, such as dietary additives, on pig colonic fermentation.

  19. In vitro continuous fermentation model (PolyFermS of the swine proximal colon for simultaneous testing on the same gut microbiota.

    Directory of Open Access Journals (Sweden)

    Sabine A Tanner

    Full Text Available In vitro gut modeling provides a useful platform for a fast and reproducible assessment of treatment-related changes. Currently, pig intestinal fermentation models are mainly batch models with important inherent limitations. In this study we developed a novel in vitro continuous fermentation model, mimicking the porcine proximal colon, which we validated during 54 days of fermentation. This model, based on our recent PolyFermS design, allows comparing different treatment effects on the same microbiota. It is composed of a first-stage inoculum reactor seeded with immobilized fecal swine microbiota and used to constantly inoculate (10% v/v five second-stage reactors, with all reactors fed with fresh nutritive chyme medium and set to mimic the swine proximal colon. Reactor effluents were analyzed for metabolite concentrations and bacterial composition by HPLC and quantitative PCR, and microbial diversity was assessed by 454 pyrosequencing. The novel PolyFermS featured stable microbial composition, diversity and metabolite production, consistent with bacterial activity reported for swine proximal colon in vivo. The constant inoculation provided by the inoculum reactor generated reproducible microbial ecosystems in all second-stage reactors, allowing the simultaneous investigation and direct comparison of different treatments on the same porcine gut microbiota. Our data demonstrate the unique features of this novel PolyFermS design for the swine proximal colon. The model provides a tool for efficient, reproducible and cost-effective screening of environmental factors, such as dietary additives, on pig colonic fermentation.

  20. Generation of an inducible colon-specific Cre enzyme mouse line for colon cancer research

    NARCIS (Netherlands)

    Tetteh, Paul W.; Kretzschmar, Kai; Begthel, Harry; Van Den Born, Maaike; Korving, Jeroen; Morsink, Folkert; Farin, Henner; Van Es, Johan H.; Offerhaus, G. Johan A; Clevers, Hans

    2016-01-01

    Current mouse models for colorectal cancer often differ significantly from human colon cancer, being largely restricted to the small intestine. Here, we aim to develop a colon-specific inducible mouse model that can faithfully recapitulate human colon cancer initiation and progression. Carbonic

  1. Ambient ultraviolet radiation in the Arctic reduces root biomass and alters microbial community composition but has no effects on microbial biomass

    DEFF Research Database (Denmark)

    Rinnan, R.; Keinänen, M.M.; Kasurinen, A.

    2005-01-01

    We assessed the effects of ambient solar ultraviolet (UV) radiation on below-ground parameters in an arctic heath in north-eastern Greenland. We hypothesized that the current UV fluxes would reduce root biomass and mycorrhizal colonization and that these changes would lead to lower soil microbial...... biomass and altered microbial community composition. These hypotheses were tested on cored soil samples from a UV reduction experiment with three filter treatments (Mylar, 60% UV-B reduction; Lexan, up to 90% UV-B reduction+UV-A reduction; UV transparent Teflon, filter control) and an open control...... treatment in two study sites after 3 years' manipulation. Reduction of both UV-A and UV-B radiation caused over 30% increase in the root biomass of Vaccinium uliginosum, which was the dominant plant species. UV reduction had contrasting effects on ericoid mycorrhizal colonization of V. uliginosum roots...

  2. Right colon cancer: Left behind.

    Science.gov (United States)

    Gervaz, P; Usel, M; Rapiti, E; Chappuis, P; Neyroud-Kaspar, I; Bouchardy, C

    2016-09-01

    Prognosis of colon cancer (CC) has steadily improved during the past three decades. This trend, however, may vary according to proximal (right) or distal (left) tumor location. We studied if improvement in survival was greater for left than for right CC. We included all CC recorded at the Geneva population-based registry between 1980 and 2006. We compared patients, tumor and treatment characteristics between left and right CC by logistic regression and compared CC specific survival by Cox models taking into account putative confounders. We also compared changes in survival between CC location in early and late years of observation. Among the 3396 CC patients, 1334 (39%) had right-sided and 2062 (61%) left-sided tumors. In the early 1980s, 5-year specific survival was identical for right and left CCs (49% vs. 48%). During the study period, a dramatic improvement in survival was observed for patients with left-sided cancers (Hazard ratio [HR]: 0.42, 95% confidence interval [CI]: 0.29-0.62, p colon cancer patients, those with right-sided lesions have by far the worse prognosis. Change of strategic management in this subgroup is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Dietary pattern and colonic diverticulosis.

    Science.gov (United States)

    Tursi, Antonio

    2017-09-01

    To assess the role of dietary pattern on the occurrence of colonic diverticulosis, diverticular disease and acute diverticulitis. High-fiber diet does not prevent diverticulosis occurrence, and results about prevention/treatment of diverticular disease and acute diverticulitis are still conflicting.No association was seen between nut, corn or popcorn consumption and occurrence of diverticulosis, diverticular disease and acute diverticulitis.It seems to be a mild association between high alcohol intake and diverticulosis occurrence, whereas alcohol dependence seems to show lower risk of in-hospital mortality due to acute diverticulitis.Higher red-meat consumption shows mild increased risk of acute diverticulitis, especially when consumed as unprocessed red meat (defined as consumption of 'beef or lamb as main dish', 'pork as main dish', 'hamburger' and 'beef, pork or lamb as a sandwich or mixed dish'); higher consumption of poultry (viz. white meat) was not associated with risk of acute diverticulitis.Finally, higher fish intake was associated with reduced risk of diverticulitis in age-adjusted model, but not after further adjustment for other potential confounders. Current literature data about the role of dietary pattern on the occurrence of colonic diverticulosis, diverticular disease and acute diverticulitis are still too conflicting.

  4. Dimensions of driving anger and their relationships with aberrant driving.

    Science.gov (United States)

    Zhang, Tingru; Chan, Alan H S; Zhang, Wei

    2015-08-01

    The purpose of this study was to investigate the relationship between driving anger and aberrant driving behaviours. An internet-based questionnaire survey was administered to a sample of Chinese drivers, with driving anger measured by a 14-item short Driving Anger Scale (DAS) and the aberrant driving behaviours measured by a 23-item Driver Behaviour Questionnaire (DBQ). The results of Confirmatory Factor Analysis demonstrated that the three-factor model (hostile gesture, arrival-blocking and safety-blocking) of the DAS fitted the driving anger data well. The Exploratory Factor Analysis on DBQ data differentiated four types of aberrant driving, viz. emotional violation, error, deliberate violation and maintaining progress violation. For the anger-aberration relation, it was found that only "arrival-blocking" anger was a significant positive predictor for all four types of aberrant driving behaviours. The "safety-blocking" anger revealed a negative impact on deliberate violations, a finding different from previously established positive anger-aberration relation. These results suggest that drivers with different patterns of driving anger would show different behavioural tendencies and as a result intervention strategies may be differentially effective for drivers of different profiles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Control rod drive mechanism

    International Nuclear Information System (INIS)

    Nakamura, Akira.

    1981-01-01

    Purpose: To ensure the scram operation of a control rod by the reliable detection for the position of control rods. Constitution: A permanent magnet is provided to the lower portion of a connecting rod in engagement with a control rod and a tube having a plurality of lead switches arranged axially therein in a predetermined pitch is disposed outside of the control rod drives. When the control rod moves upwardly in the scram operation, the lead switches are closed successively upon passage of the permanent magnet to operate the electrical circuit provided by way of each of the lead switches. Thus, the position for the control rod during the scram can reliably be determined and the scram characteristic of the control rod can be recognized. (Furukawa, Y.)

  6. [Epilepsy and driving].

    Science.gov (United States)

    Matsuura, Masato

    2014-05-01

    In Japan, the Road Traffic Act was amended in June 2013, including new penalty to false statement in a disease condition declaration form, and new voluntary notification system for a doctor who is aware that a person is at high risk for traffic accident and in possession of a driver license. Moreover, New Criminal Law Act was established in November 2013, including a prison sentence of up to 15 years for persons, who under the influence of specific drugs or diseases, causing death or injury to other persons by driving a motor vehicle. Both laws are supposed to be enforced during 2014, after additional resolutions including the review of the laws after five years, considerations so as not to create discrimination due to diseases, etc are examined.

  7. Control rod drives

    International Nuclear Information System (INIS)

    Furumitsu, Yutaka.

    1981-01-01

    Purpose: To improve the reliability of a device for driving an LMFBR type reactor control rod by providing a buffer unit having a stationary electromagnetic coil and a movable electromagnetic coil in the device to thereby avord impact stress at scram time and to simplify the structure of the buffer unit. Constitution: A non-contact type buffer unit is constructed with a stationary electromagnetic coil, a cable for the stationary coil, a movable electromagnetic coil, a spring cable for the movable coil, and a backup coil spring or the like. Force produced at scram time is delivered without impact by the attracting or repelling force between the stationary coil and the movable coil of the buffer unit. Accordingly, since the buffer unit is of a non-contact type, there is no mechanical impact and thus no large impact stress, and as it has simple configuration, the reliability is improved and the maintenance can be conducted more easily. (Yoshihara, H.)

  8. Control rod drives

    International Nuclear Information System (INIS)

    Yamanaka, Toshikatsu.

    1979-01-01

    Purpose: To protect bellows against failures due to negative pressure to prevent the loss of pressure balance caused by the expansion of the bellows upon scram. Constitution: An expansion pipe connected to the control rod drive is driven along a guide pipe to insert a control rod into the reactor core. Expansible bellows are provided at the step between the expansion pipe and the guide pipe. Further, a plurality of bore holes or slits are formed on the side wall of the guide pipe corresponding to the expansion portion of the bellows. In such an arrangement, when the expansion pipe falls rapidly and the bellows are expanded upon scram, the volume between each of the pipes of the bellows and the guide pipe is increased to produce a negative pressure, but the effect of the negative pressure on the bellows can be eliminated by the flowing-in of coolants corresponding to that pressure through the bore holes or the slits. (Furukawa, Y.)

  9. Microbial community assembly and metabolic function during mammalian corpse decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Metcalf, J. L.; Xu, Z. Z.; Weiss, S.; Lax, S.; Van Treuren, W.; Hyde, E. R.; Song, S. J.; Amir, A.; Larsen, P.; Sangwan, N.; Haarmann, D.; Humphrey, G. C.; Ackermann, G.; Thompson, L. R.; Lauber, C.; Bibat, A.; Nicholas, C.; Gebert, M. J.; Petrosino, J. F.; Reed, S. C.; Gilbert, J. A.; Lynne, A. M.; Bucheli, S. R.; Carter, D. O.; Knight, R.

    2015-12-10

    Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet microbially mediated processes are poorly understood. Here we combine deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand the principles governing microbial community assembly during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups that contribute to nitrogen cycling and a reproducible network of decomposers that emerge on predictable time scales. Our results show that this decomposer community is derived primarily from bulk soil, but key decomposers are ubiquitous in low abundance. Soil type was not a dominant factor driving community development, and the process of decomposition is sufficiently reproducible to offer new opportunities for forensic investigations.

  10. Microbial community assembly and metabolic function during mammalian corpse decomposition

    Science.gov (United States)

    Metcalf, Jessica L; Xu, Zhenjiang Zech; Weiss, Sophie; Lax, Simon; Van Treuren, Will; Hyde, Embriette R.; Song, Se Jin; Amir, Amnon; Larsen, Peter; Sangwan, Naseer; Haarmann, Daniel; Humphrey, Greg C; Ackermann, Gail; Thompson, Luke R; Lauber, Christian; Bibat, Alexander; Nicholas, Catherine; Gebert, Matthew J; Petrosino, Joseph F; Reed, Sasha C.; Gilbert, Jack A; Lynne, Aaron M; Bucheli, Sibyl R; Carter, David O; Knight, Rob

    2016-01-01

    Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet microbially mediated processes are poorly understood. Here we combine deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand the principles governing microbial community assembly during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups that contribute to nitrogen cycling and a reproducible network of decomposers that emerge on predictable time scales. Our results show that this decomposer community is derived primarily from bulk soil, but key decomposers are ubiquitous in low abundance. Soil type was not a dominant factor driving community development, and the process of decomposition is sufficiently reproducible to offer new opportunities for forensic investigations.

  11. Do emotions drive psychosis?

    Directory of Open Access Journals (Sweden)

    João G. Ribeiro

    2012-12-01

    Full Text Available Introduction: How important is the emotional life of persons who manifest psychotic symptoms? Aims: The aim of this paper is to review evidence on a causal role for emotions in psychotic processes. Methods: Selective review of literature on affective symptoms in psychoses, on emotions in the production of psychotic symptoms and on dopaminergic models of psychosis. Results: Affective symptoms are relevant across psychoses. Persons with schizophrenia have high levels of emotional reactivity and the intensification of negative affects not only is associated with but also precedes the intensification of psychotic symptoms, which is evidence that negative emotions drive the course of psychotic symptoms. Negative self‑representations are central in psychotic processes and can be the link between negative emotions and psychosis. Evidence favours the notion that persecutory delusions are consistent with negative affects and self‑representations, while grandiose delusions are consistent with a defensive amplification of positive affects and self‑representations. Shame has been proposed as the core emotional experience of psychosis, one in which the self becomes vulnerable to the external world, which is consistent with persecutory experiences. Assaults on the self, under the form of hostility in the family environment and society, are strong predictors of relapse and development of schizophrenia. Assaults on the self which induce social defeat are also strong stimulants of mesolimbic dopaminergic pathways, whose hyperactivity is associated with acute psychotic episodes and the experience of “aberrant salience”, put forward as a dopaminergic model of psychosis. Conclusions: The “defeat of the self” emerges as a central link that binds the experience of negative emotions to the expression of psychotic symptoms and its psychological and neurobiological correlates. The hypothesis gains support that the emotions related to that defeat control

  12. Antioxidative Effects of Phenolic Compounds of Mushroom Mycelia in Simulated Regions of the Human Colon, In Vitro Study

    Directory of Open Access Journals (Sweden)

    Vamanu Emanuel

    2018-03-01

    Full Text Available Many compounds in mushrooms are biologically active; however, the in vivo actions of their metabolites are poorly understood. An in vitro system, GIS1, was used to simulate the fermentation action of microbiota in each colon region. We used MycoPo, a natural product obtained from the lyophilized mycelia of different Pleurotus ostreatus species to determine the biological effects in human-colon regions. Controls (Lentinula edodes mycelia; dried basidia of Agaricus brunnescens were chosen to confirm the biological activity of P. ostreatus mycelia in vitro. We measured total antioxidant capacity and ferric ion-reducing antioxidant power (FRAP in simulated colon regions to identify antioxidant compounds, and undertook in vitro gastrointestinal simulation and microbiological analyses. The highest FRAP was found for the ascending colon, and the antioxidant effect was higher when MycoPo was administered. A. brunnescens consumption resulted in low total antioxidant capacity. Polyphenol content was correlated with the antioxidant status and microbial composition of microbiota. Total polyphenolic content was higher after A. brunnescens consumption, and four types of polyphenols were identified by high-performance liquid chromatography. Major phenolic acids were gentisic acid, homogentisic acid, and small amounts of caffeic acid. The Enterobacteriaceae species populations varied greatly across the three parts of the colon. We noted a significant (p0.85. These data suggest a direct relationship between favorable bacterial strains and availability of bioactive compounds, with specificity for each colon region.

  13. Effect of peristalsis in balance of intestinal microbial ecosystem

    Science.gov (United States)

    Mirbagheri, Seyed Amir; Fu, Henry C.

    2017-11-01

    A balance of microbiota density in gastrointestinal tracts is necessary for health of the host. Although peristaltic flow made by intestinal muscles is constantly evacuating the lumen, bacterial density stay balanced. Some of bacteria colonize in the secreted mucus where there is no flow, but the rest resist the peristaltic flow in lumen and maintain their population. Using a coupled two-dimensional model of flow induced by large amplitude peristaltic waves, bacterial motility, reproduction, and diffusion, we address how bacterial growth and motility combined with peristaltic flow affect the balance of the intestinal microbial ecosystem.

  14. EVA Suit Microbial Leakage Investigation

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during...

  15. A review on early gut maturation and colonization in pigs, including biological and dietary factors affecting gut homeostasis

    DEFF Research Database (Denmark)

    Everaert, Nadia; Van Cruchten, Steven; Weström, Björn

    2017-01-01

    During the prenatal, neonatal and post-weaning periods, the mammalian gastrointestinal tract undergoes various morphological and physiological changes alongside with an expansion of the immune system and microbial ecosystem. This review focuses on the time period before weaning and summarizes...... in digestive function coincides with development in both the adaptive and innate immune system. This secures a balanced immune response to the ingested milk-derived macromolecules, and colonizing bacteria. Husbandry and dietary interventions in early life appear to affect the development of multiple components...... and immunological maturation, as influenced by early microbial colonization and ingestion of dietary factors, is of utmost importance to identify management and feeding strategies to optimize intestinal health. We discuss some possible implications related to intrauterine growth restriction, and preterm delivery...

  16. Colonizing the embryonic zebrafish gut with anaerobic bacteria derived from the human gastrointestinal tract.

    Science.gov (United States)

    Toh, Michael C; Goodyear, Mara; Daigneault, Michelle; Allen-Vercoe, Emma; Van Raay, Terence J

    2013-06-01

    The zebrafish has become increasingly popular for microbiological research. It has been used as an infection model for a variety of pathogens, and is also emerging as a tool for studying interactions between a host and its resident microbial communities. The mouse microbiota has been transplanted into the zebrafish gut, but to our knowledge, there has been no attempt to introduce a bacterial community derived from the human gut. We explored two methods for colonizing the developing gut of 5-day-old germ-free zebrafish larvae with a defined anaerobic microbial community derived from a single human fecal sample. Both environmental exposure (static immersion) and direct microinjection into the gut resulted in the establishment of two species-Lactobacillus paracasei and Eubacterium limosum-from a community of 30 strains consisting of 22 anaerobic species. Of particular interest is E. limosum, which, as a strict anaerobe, represents a group of bacteria which until now have not been shown to colonize the developing zebrafish gut. Our success here indicates that further investigation of zebrafish as a tool for studying human gut microbial communities is warranted.

  17. CLIC Drive Beam Phase Stabilisation

    CERN Document Server

    Gerbershagen, Alexander; Schulte, Daniel

    The thesis presents phase stability studies for the Compact Linear Collider (CLIC) and focuses in particular on CLIC Drive Beam longitudinal phase stabilisation. This topic constitutes one of the main feasibility challenges for CLIC construction and is an essential component of the current CLIC stabilisation campaign. The studies are divided into two large interrelated sections: the simulation studies for the CLIC Drive Beam stability, and measurements, data analysis and simulations of the CLIC Test Facility (CTF3) Drive Beam phase errors. A dedicated software tool has been developed for a step-by-step analysis of the error propagation through the CLIC Drive Beam. It uses realistic RF potential and beam loading amplitude functions for the Drive and Main Beam accelerating structures, complete models of the recombination scheme and compressor chicane as well as of further CLIC Drive Beam modules. The tool has been tested extensively and its functionality has been verified. The phase error propagation at CLIC h...

  18. H1 antihistamines and driving.

    Science.gov (United States)

    Popescu, Florin Dan

    2008-01-01

    Driving performances depend on cognitive, psychomotor and perception functions. The CNS adverse effects of some H1 antihistamines can alter the patient ability to drive. Data from studies using standardized objective cognitive and psychomotor tests (Choice Reaction Time, Critical Flicker Fusion. Digital Symbol Substitution Test), functional brain imaging (Positron Emission Tomography, functional Magnetic Resonance Imaging), neurophysiological studies (Multiple Sleep Latency Test, auditory and visual evoked potentials), experimental simulated driving (driving simulators) and real driving studies (the Highway Driving Test, with the evaluation of the Standard Deviation Lateral Position, and the Car Following Test, with the measurement of the Brake Reaction Time) must be discussed in order to classify a H1 antihistamine as a true non-sedating one.

  19. Can Phlorotannins Purified Extracts Constitute a Novel Pharmacological Alternative for Microbial Infections with Associated Inflammatory Conditions?

    Science.gov (United States)

    Lopes, Graciliana; Sousa, Carla; Silva, Luís R.; Pinto, Eugénia; Andrade, Paula B.; Bernardo, João; Mouga, Teresa; Valentão, Patrícia

    2012-01-01

    Bacterial and fungal infections and the emerging multidrug resistance are driving interest in fighting these microorganisms with natural products, which have generally been considered complementary to pharmacological therapies. Phlorotannins are polyphenols restricted to brown seaweeds, recognized for their biological capacity. This study represents the first research on the antibacterial, antifungal, anti-inflammatory and antioxidant activity of phlorotannins purified extracts, which were obtained from ten dominant brown seaweeds of the occidental Portuguese coast. Phlorotannins content was determined by the specific dimethoxybenzaldehyde (DMBA) method and a yield between 75 and 969 mg/Kg phloroglucinol units (dry matter) was obtained. Fucus spiralis ranked first, followed by three Cystoseira species. The anti-inflammatory potential of the purified extracts was assessed via inhibitory effect on nitric oxide (NO) production by lipopolysaccharide-stimulated RAW 264.7 macrophage cells, Cystoseira tamariscifolia being the one showing promising activity for the treatment of inflammation. NO scavenging ability was also addressed in cell free systems, F. spiralis being the species with highest capacity. The antimicrobial potential of the extracts was checked against five Gram-positive and four Gram-negative bacteria and three fungi strains, that commonly colonize skin and mucosa and are responsible for food contamination. The different extracts were more effective against Gram-positive bacteria, Staphylococcus epidermidis being the most susceptible species. Concerning antifungal activity, Trichophyton rubrum was the most sensitive species. Although the molecular mechanisms underlying these properties remain poorly understood, the results obtained turn phlorotannins purified extracts a novel and potent pharmacological alternative for the treatment of a wide range of microbial infections, which usually also present an inflammatory component. In addition to the biological

  20. Microbial biogeography of San Francisco Bay sediments

    Science.gov (United States)

    Lee, J. A.; Francis, C. A.

    2014-12-01

    whether patterns of diversity observed at the broadest of taxonomic scales also apply to patterns observed within a single extremely diverse gene (nirS). In sum, this project provides a first look at the forces driving the migration and selection of microbial communities in San Francisco Bay.

  1. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium

    International Nuclear Information System (INIS)

    Teixeira, Catarina; Almeida, C. Marisa R.; Nunes da Silva, Marta; Bordalo, Adriano A.; Mucha, Ana P.

    2014-01-01

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Capsule abstract: Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. - Highlights: • Cd resistant microbial consortia were developed and applied to salt-marsh sediments. • In Phragmites australis the consortia amendment promoted metal phytoextraction. • The consortia addition increased Juncus maritimus phytostabilization capacity. • No long term changes on the rhizosediment bacterial structure were observed

  2. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Catarina [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Laboratório de Hidrobiologia e Ecologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal); Almeida, C. Marisa R.; Nunes da Silva, Marta [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Bordalo, Adriano A. [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Laboratório de Hidrobiologia e Ecologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal); Mucha, Ana P., E-mail: amucha@ciimar.up.pt [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal)

    2014-09-15

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Capsule abstract: Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. - Highlights: • Cd resistant microbial consortia were developed and applied to salt-marsh sediments. • In Phragmites australis the consortia amendment promoted metal phytoextraction. • The consortia addition increased Juncus maritimus phytostabilization capacity. • No long term changes on the rhizosediment bacterial structure were observed.

  3. Failure Prediction for Autonomous Driving

    OpenAIRE

    Hecker, Simon; Dai, Dengxin; Van Gool, Luc

    2018-01-01

    The primary focus of autonomous driving research is to improve driving accuracy. While great progress has been made, state-of-the-art algorithms still fail at times. Such failures may have catastrophic consequences. It therefore is important that automated cars foresee problems ahead as early as possible. This is also of paramount importance if the driver will be asked to take over. We conjecture that failures do not occur randomly. For instance, driving models may fail more likely at places ...

  4. The Drive-Wise Project: Driving Simulator Training increases real driving performance in healthy older drivers

    Directory of Open Access Journals (Sweden)

    Gianclaudio eCasutt

    2014-05-01

    Full Text Available Background: Age-related cognitive decline is often associated with unsafe driving behavior. We hypothesized that 10 active training sessions in a driving simulator increase cognitive and on-road driving performance. In addition, driving simulator training should outperform cognitive training.Methods: Ninety-one healthy active drivers (62 – 87 years were randomly assigned to either (1 a driving simulator training group, (2 an attention training group (vigilance and selective attention, or (3 a control group. The main outcome variables were on-road driving and cognitive performance. Seventy-seven participants (85% completed the training and were included in the analyses. Training gains were analyzed using a multiple regression analysis with planned comparisons.Results: The driving simulator training group showed an improvement in on-road driving performance compared to the attention training group. In addition, both training groups increased cognitive performance compared to the control group. Conclusion: Driving simulator training offers the potential to enhance driving skills in older drivers. Compared to the attention training, the simulator training seems to be a more powerful program for increasing older drivers’ safety on the road.

  5. Imaging of total colonic Hirschsprung disease

    International Nuclear Information System (INIS)

    Stranzinger, Enno; DiPietro, Michael A.; Strouse, Peter J.; Teitelbaum, Daniel H.

    2008-01-01

    Hirschsprung disease (HD) is a functional obstruction of the bowel caused by the absence of intrinsic enteric ganglion cells. The diagnosis of total colonic HD (TCHD) based on contrast enemas is difficult in newborns because radiological findings vary. To evaluate the radiographic and contrast enema findings in patients with pathologically proven TCHD. From 1966 to 2007, 17 records from a total of 31 patients with TCHD were retrospectively evaluated for diameter and shape of the colon, diameter of the small bowel, bowel wall contour, ileal reflux, abdominal calcifications, pneumoperitoneum, filling defects, transitional zones and rectosigmoid index. Three colonic patterns of TCHD were found: microcolon, question-mark-shape colon and normal caliber colon. Additional findings included spasmodic colon, ileal reflux, delayed evacuation and abdominal calcifications. Colonic transitional zones were found in eight patients with TCHD. The diagnosis of TCHD is difficult to establish by contrast enema studies. The length of the aganglionic small bowel and the age of the patient can influence the radiological findings in TCHD. The transitional zone and the rectosigmoid index can be false-positive in TCHD. The colon can appear normal. Consider TCHD if the contrast enema study is normal but the patient remains symptomatic and other causes of distal bowel obstruction have been excluded. (orig.)

  6. Seat belt injuries and sigmoid colon trauma.

    OpenAIRE

    Eltahir, E M; Hamilton, D

    1997-01-01

    Colonic seat belt injuries are rare but carry higher mortality rates than small bowel injuries. The case of a 44 year old man is described who had severe sigmoid colon compression injury from his seat belt a few days after a road traffic accident.

  7. A Study Of Fungal Colonization In Newborn

    Directory of Open Access Journals (Sweden)

    S Rashid Husain

    1997-04-01

    Full Text Available Research Problem: What are the factors responsible for fungal colonization in newborns? Objective: To study the pattern of and predisposing fac­tors for the development of superficial candidiasis and fungal colonization in the newborns. Study Design: Prospective study. Setting: Neonatology unitof the Paediatrics department of a teaching hospital. Participants: Randomly selected pregnant mothers admit­ted to the maternity ward and the newborns delivered to them. Sample Size: 120 pregnant mothers and the newborns delivered. Study Variables: Candida, Site of colonization. Statistical Analysis: By tests of significance Results: Candida was isolated from 23 (19.16% infants on the first day increasing to 52 (43.33% infants on the sixth day. The most common site of colonization was oral cavity. Candida colonization was more common in prema­ture infants (p<0.05. Oral thrush was seen in 29 (24.17% infants during the study and a significant number of these infants showed colonization from the first day of life. Conclusions: Fungal colonization of the newborns due to Candida species is quite common, and in the first week of life predominantly occurred in the ora I cavity. Superficial clinical candidiasis, especially oral thrush is more common in those colonized on the first day of life.

  8. Role of neutral ceramidase in colon cancer.

    Science.gov (United States)

    García-Barros, Mónica; Coant, Nicolas; Kawamori, Toshihiko; Wada, Masayuki; Snider, Ashley J; Truman, Jean-Philip; Wu, Bill X; Furuya, Hideki; Clarke, Christopher J; Bialkowska, Agnieszka B; Ghaleb, Amr; Yang, Vincent W; Obeid, Lina M; Hannun, Yusuf A

    2016-12-01

    Alterations in sphingolipid metabolism, especially ceramide and sphingosine 1-phosphate, have been linked to colon cancer, suggesting that enzymes of sphingolipid metabolism may emerge as novel regulators and targets in colon cancer. Neutral ceramidase (nCDase), a key enzyme in sphingolipid metabolism that hydrolyzes ceramide into sphingosine, is highly expressed in the intestine; however, its role in colon cancer has not been defined. Here we show that molecular and pharmacological inhibition of nCDase in colon cancer cells increases ceramide, and this is accompanied by decreased cell survival and increased apoptosis and autophagy, with minimal effects on noncancerous cells. Inhibition of nCDase resulted in loss of β-catenin and inhibition of ERK, components of pathways relevant for colon cancer development. Furthermore, inhibition of nCDase in a xenograft model delayed tumor growth and increased ceramide while decreasing proliferation. It is noteworthy that mice lacking nCDase treated with azoxymethane were protected from tumor formation. Taken together, these studies show that nCDase is pivotal for regulating initiation and development of colon cancer, and these data suggest that this enzyme is a suitable and novel target for colon cancer therapy.-García-Barros, M., Coant, N., Kawamori, T., Wada, M., Snider, A. J., Truman, J.-P., Wu, B. X., Furuya, H., Clarke, C. J., Bialkowska, A. B., Ghaleb, A., Yang, V. W., Obeid, L. M., Hannun, Y. A. Role of neutral ceramidase in colon cancer. © FASEB.

  9. Congenital segmental dilatation of the colon

    African Journals Online (AJOL)

    Congenital segmental dilatation of the colon is a rare cause of intestinal obstruction in neonates. We report a case of congenital segmental dilatation of the colon and highlight the clinical, radiological, and histopathological features of this entity. Proper surgical treatment was initiated on the basis of preoperative radiological ...

  10. Incidence of retrorenal colon during percutaneous nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Mehmet Balasar

    2015-04-01

    Full Text Available Objective The aim of this study was to investigate retrorenal colon incidence in percutaneous nephrolithotomy (PNL interventions made in our clinic. Materials and Methods Clinical data of 804 PNL patients, accumulated over a 7 year period (2006-2012, was surveyed. The patient files were reviewed retrospectively, and only those who had abdominal computed tomography (CT images before PNL intervention were included in the study. In the CT images, the position of both the ascending and descending colon in relation to the right and left kidneys were evaluated. Results According to our hospital reports, 394 patients with CT images were included in the present study 27 patients (6.9% had retrorenal colon, of which 18 (4.6% were on the left side, 4 (1.0% on the right side and 5 (1.3% had bilateral retrorenal colons. Colonic perforation complication was seen only in two patients and the colonic perforation rate was 0.3%. These two cases had no CT images. Conclusions PNL, in the process of becoming the standard treatment modality, is a safe and reliable technique for renal stone treatment. Colonic injury should be taken into consideration during PNL interventions of the lower pole of the kidney (especially on the left side due to the location of retrorenal colon.

  11. The colon shuffle : A modified urinary diversion

    NARCIS (Netherlands)

    Meijer, R. P.; Mertens, L. S.; Meinhardt, W.; Verwaal, V. J.; Dik, P.; Horenblas, S.

    2015-01-01

    Aim To assess the results of a urinary diversion in patients who already have a colostomy or simultaneously require a (rectum) colon resection. The diversion is created from the distal part of the transected colon with a simultaneously created new colostomy contra-laterally (if necessary). This

  12. Colonic ischemic necrosis following therapeutic embolization

    International Nuclear Information System (INIS)

    Shenoy, S.S.; Satchidanand, S.; Wesp, E.H.; State Univ. of New York, Buffalo

    1981-01-01

    Transcatheter embolization of the middle colic artery for diverticular bleeding was followed by ischemic necrosis in the transverse colon at the site of previous anastomosis and stricture formation. This is a potential complication of intra-arterial embolization for colonic bleeding. (orig.)

  13. Colonic ischemic necrosis following therapeutic embolization

    Energy Technology Data Exchange (ETDEWEB)

    Shenoy, S S; Satchidanand, S; Wesp, E H

    1981-07-15

    Transcatheter embolization of the middle colic artery for diverticular bleeding was followed by ischemic necrosis in the transverse colon at the site of previous anastomosis and stricture formation. This is a potential complication of intra-arterial embolization for colonic bleeding.

  14. 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

  15. Mineralogic control on abundance and diversity of surface-adherent microbial communities

    Science.gov (United States)

    Mauck, Brena S.; Roberts, Jennifer A.

    2007-01-01

    In this study, we investigated the role of mineral-bound P and Fe in defining microbial abundance and diversity in a carbon-rich groundwater. Field colonization experiments of initially sterile mineral surfaces were combined with community structure characterization of the attached microbial population. Silicate minerals containing varying concentrations of P (∼1000 ppm P) and Fe (∼4 wt % Fe 2 O3), goethite (FeOOH), and apatite [Ca5(PO4)3(OH)] were incubated for 14 months in three biogeochemically distinct zones within a petroleum-contaminated aquifer. Phospholipid fatty acid analysis of incubated mineral surfaces and groundwater was used as a measure of microbial community structure and biomass. Microbial biomass on minerals exhibited distinct trends as a function of mineralogy depending on the environment of incubation. In the carbon-rich, aerobic groundwater attached biomass did not correlate to the P- or Fe- content of the mineral. In the methanogenic groundwater, however, biomass was most abundant on P-containing minerals. Similarly, in the Fe-reducing groundwater a correlation between Fe-content and biomass was observed. The community structure of the mineral-adherent microbial population was compared to the native groundwater community. These two populations were significantly different regardless of mineralogy, suggesting differentiation of the planktonic community through attachment, growth, and death of colonizing cells. Biomarkers specific for dissimilatory Fe-reducing bacteria native to the aquifer were identified only on Fe-containing minerals in the Fe-reducing groundwater. These results demonstrate that the trace nutrient content of minerals affects both the abundance and diversity of surface-adherent microbial communities. This behavior may be a means to access limiting nutrients from the mineral, creating a niche for a particular microbial population. These results suggest that heterogeneity of microbial populations and their associated

  16. Noninductive current drive in tokamaks

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1985-01-01

    Various current drive mechanisms may be grouped into four classes: (1) injection of energetic particle beams; (2) launching of rf waves; (3) hybrid schemes, which are combinations of various rf schemes (rf plus beams, rf and/or beam plus ohmic heating, etc.); and (4) other schemes, some of which are specific to reactor plasma conditions requiring the presence of alpha particle or intense synchrotron radiation. Particle injection schemes include current drive by neutral beams and relativistic electron beams. The rf schemes include current drive by the lower hybrid (LH) waves, the electron waves, the waves in the ion cyclotron range of frequencies, etc. Only a few of these approaches, however, have been tested experimentally, with the broadest data base available for LH waves. Included in this report are (1) efficiency criteria for current drive, (2) current drive by neutral beam injection, (3) LH current drive, (4) electron cyclotron current drive, (5) current drive by ion cyclotron waves - minority species heating, and (6) current drive by other schemes (such as hybrids and low frequency waves)

  17. Mechanistic links between gut microbial community dynamics, microbial functions and metabolic health

    Science.gov (United States)

    Ha, Connie WY; Lam, Yan Y; Holmes, Andrew J

    2014-01-01

    Gut microbes comprise a high density, biologically active community that lies at the interface of an animal with its nutritional environment. Consequently their activity profoundly influences many aspects of the physiology and metabolism of the host animal. A range of microbial structural components and metabolites directly interact with host intestinal cells and tissues to influence nutrient uptake and epithelial health. Endocrine, neuronal and lymphoid cells in the gut also integrate signals from these microbial factors to influence systemic responses. Dysregulation of these host-microbe interactions is now recognised as a major risk factor in the development of metabolic dysfunction. This is a two-way process and understanding the factors that tip host-microbiome homeostasis over to dysbiosis requires greater appreciation of the host feedbacks that contribute to regulation of microbial community composition. To date, numerous studies have employed taxonomic profiling approaches to explore the links between microbial composition and host outcomes (especially obesity and its comorbidities), but inconsistent host-microbe associations have been reported. Available data indicates multiple factors have contributed to discrepancies between studies. These include the high level of functional redundancy in host-microbiome interactions combined with individual variation in microbiome composition; differences in study design, diet composition and host system between studies; and inherent limitations to the resolution of rRNA-based community profiling. Accounting for these factors allows for recognition of the common microbial and host factors driving community composition and development of dysbiosis on high fat diets. New therapeutic intervention options are now emerging. PMID:25469018

  18. Bacterial Colonization of Disposable Soft Contact Lenses Is Greater during Corneal Infiltrative Events than during Asymptomatic Extended Lens Wear

    OpenAIRE

    Sankaridurg, Padmaja R.; Sharma, Savitri; Willcox, Mark; Naduvilath, Thomas J.; Sweeney, Deborah F.; Holden, Brien A.; Rao, Gullapalli N.

    2000-01-01

    Microorganisms, especially gram-negative bacteria, are considered to play a role in the etiology of certain corneal infiltrative events (CIEs) observed during soft contact lens wear. This study explored the possibility of microbial colonization of soft contact lenses as a risk factor leading to CIEs. In a clinical trial conducted from March 1993 to January 1996, 330 subjects wore disposable soft contact lenses on a 6-night extended-wear and disposal schedule. During this period, 4,321 lenses ...

  19. A prognostic analysis of 895 cases of stage III colon cancer in different colon subsites.

    Science.gov (United States)

    Zhang, Yan; Ma, Junli; Zhang, Sai; Deng, Ganlu; Wu, Xiaoling; He, Jingxuan; Pei, Haiping; Shen, Hong; Zeng, Shan

    2015-09-01

    Stage III colon cancer is currently treated as an entity with a unified therapeutic principle. The aim of the retrospective study is to explore the clinicopathological characteristics and outcomes of site-specific stage III colon cancers and the influences of tumor location on prognosis. Eight hundred ninety-five patients with stage III colon cancer treated with radical operation and subsequent adjuvant chemotherapy (5-fluorouracil/oxaliplatin) were divided into seven groups according to colon segment (cecum, ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, and sigmoid colon). Expression of excision repair cross-complementing group 1 (ERCC1) and thymidylate synthase (TS) was examined by immunohistochemistry. We assessed if differences exist in patient characteristics and clinic outcomes between the seven groups. There were significant differences in tumor differentiation (P Cancer (AJCC) tumor-node-metastasis (TNM) stage (P colon. Cox regression analyses identified that tumor location was an independent prognostic factor for RFS and OS. Stage III colon cancer located proximally carried a poorer survival than that located distally. Different efficacies of FOLFOX adjuvant chemotherapy may be an important factor affecting survival of site-specific stage III colon cancers.

  20. Association between colonic polyps and diverticular disease

    Institute of Scientific and Technical Information of China (English)

    Tetsuo Hirata; Yuko Kawakami; Nagisa Kinjo; Susumu Arakald; Tetsu Arakaki; Akira Hokama; Fukunori Kinjo; Jim Fujita

    2008-01-01

    AIM: TO evaluate the association between colonic polyps and diverticular disease in Japan.METHODS: We retrospectively reviewed the medical records of 672 consecutive patients who underwent total colonoscopy between August 2006 and April 2007 at Nishinjo Hospital, Okinawa, Japan. Patients with ahistory of any of the following were excluded from the study: previous polypectomy, colonic resection, and inflammatory bowel diseases. The association between colonic polyps and diverticular disease was analyzed by logistic regression analysis, adjusted for age and sex.RESULTS: Prevalence of colonic polyps in all patients with diverticular disease was significantly higher than that in those without diverticular disease (adjusted odds ratio 1.7).CONCLUSION: Our data showed that patients with diverticular disease have a higher risk of colonic polyps compared to those without.

  1. Duplication Cyst of the Sigmoid Colon

    Directory of Open Access Journals (Sweden)

    Bastian Domajnko

    2009-01-01

    Full Text Available A 21-year-old male with developmental delay presented with abdominal pain of two days' duration. He was afebrile and his abdomen was soft with mild diffuse tenderness. There were no peritoneal signs. Plain x-ray demonstrated a large air-filled structure in the right upper quadrant. Computed tomography of the abdomen revealed a 9×8 cm structure adjacent to the hepatic flexure containing an air-fluid level. It did not contain oral contrast and had no apparent communication with the colon. At operation, the cystic lesion was identified as a duplication cyst of the sigmoid colon that was adherent to the right upper quadrant. The cyst was excised with a segment of the sigmoid colon and a stapled colo-colostomy was performed. Recovery was uneventful. Final pathology was consistent with a duplication cyst of the sigmoid colon. The cyst was attached to the colon but did not communicate with the lumen.

  2. Association between colonic polyps and diverticular disease

    Science.gov (United States)

    Hirata, Tetsuo; Kawakami, Yuko; Kinjo, Nagisa; Arakaki, Susumu; Arakaki, Tetsu; Hokama, Akira; Kinjo, Fukunori; Fujita, Jiro

    2008-01-01

    AIM: To evaluate the association between colonic polyps and diverticular disease in Japan. METHODS: We retrospectively reviewed the medical records of 672 consecutive patients who underwent total colonoscopy between August 2006 and April 2007 at Nishinjo Hospital, Okinawa, Japan. Patients with a history of any of the following were excluded from the study: previous polypectomy, colonic resection, and inflammatory bowel diseases. The association between colonic polyps and diverticular disease was analyzed by logistic regression analysis, adjusted for age and sex. RESULTS: Prevalence of colonic polyps in all patients with diverticular disease was significantly higher than that in those without diverticular disease (adjusted odds ratio 1.7). CONCLUSION: Our data showed that patients with diverticular disease have a higher risk of colonic polyps compared to those without. PMID:18416471

  3. Immunological comparison of ovarian and colonic CEA

    International Nuclear Information System (INIS)

    Burtin, P.; Gendron, M.C.; Maunoury, M.T.; Lamerz, R.; Schnabel, G.

    1982-01-01

    Ovarian and colonic CEA were compared immunologically by means of antisera prepared against each of them. CEAs of both origins were found identical by immunodiffusion methods. In radioimmunological experiments, slight differences were observed between some but not all ovarian CEAs and colonic CEAs and also between different preparations of colonic CEA: no organ specificity of ovarian CEA could be demonstrated. Finally, CEA level was measured in 41 sera of patients with ovarian carcinoma by two radioimmunoassays, one using colonic CEA as tracer and standard and anti-colonic CEA serum, the other using ovarian CEA and anti-ovarian CEA serum: the values given by the two assays were highly correlated (rsub(s) = 0.8107), meaning that an organ specific assay for ovarian CEA is not needed. (Auth.)

  4. Diazotrophic microbial mats

    NARCIS (Netherlands)

    Severin, I.; Stal, L.J.; Seckbach, J.; Oren, A.

    2010-01-01

    Microbial mats have been the focus of scientific research for a few decades. These small-scale ecosystems are examples of versatile benthic communities of microorganisms, usually dominated by phototrophic bacteria (e.g., Krumbein et al., 1977; Jørgensen et al., 1983). They develop as vertically

  5. Microbial Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Merry [American Society for Microbiology (ASM), Washington, DC (United States); Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

    2006-10-01

    The American Academy of Microbiology convened a colloquium March 10-12, 2006, in San Francisco, California, to discuss the production of energy fuels by microbial conversions. The status of research into various microbial energy technologies, the advantages and disadvantages of each of these approaches, research needs in the field, and education and training issues were examined, with the goal of identifying routes for producing biofuels that would both decrease the need for fossil fuels and reduce greenhouse gas emissions. Currently, the choices for providing energy are limited. Policy makers and the research community must begin to pursue a broader array of potential energy technologies. A diverse energy portfolio that includes an assortment of microbial energy choices will allow communities and consumers to select the best energy solution for their own particular needs. Funding agencies and governments alike need to prepare for future energy needs by investing both in the microbial energy technologies that work today and in the untested technologies that will serve the world’s needs tomorrow. More mature bioprocesses, such as ethanol production from starchy materials and methane from waste digestors, will find applications in the short term. However, innovative techniques for liquid fuel or biohydrogen production are among the longer term possibilities that should also be vigorously explored, starting now. Microorganisms can help meet human energy needs in any of a number of ways. In their most obvious role in energy conversion, microorganisms can generate fuels, including ethanol, hydrogen, methane, lipids, and butanol, which can be burned to produce energy. Alternatively, bacteria can be put to use in microbial fuel cells, where they carry out the direct conversion of biomass into electricity. Microorganisms may also be used some day to make oil and natural gas technologies more efficient by sequestering carbon or by assisting in the recovery of oil and

  6. Microbial electrosynthesis of biochemicals

    NARCIS (Netherlands)

    Bajracharya, S.

    2016-01-01

    Microbial electrosynthesis (MES) is an electricity-driven production of chemicals from low-value waste using microorganisms as biocatalysts. MES from CO2 comprises conversion of CO2 to multi-carbon compounds employing microbes at the cathode which use electricity as an energy source. This thesis

  7. [Continent colostomy and colon irrigation].

    Science.gov (United States)

    Kostov, D; Temelkov, T; Kiriazov, E; Ivanov, K; Ignatov, V; Kobakov, G

    2000-01-01

    The authors have studied a functional activity of a continent colostomy at 20 patients, undergone an abdomeno-perineal extirpation of rectum and carried out periodic colonirrigations, during a period of 6 months. A conus type, closed irrigating system has been used. The degree of an incontinency at patients has been compared before and after the beginning of the colonirrigations. The irrigating procedures have reduced spontaneous defications at patients during a week 28 times and have improved the quality of life significantly. The application of colostomy bags has been restricted in 8 (40%) patients. An intraluminal ultrasonographic investigation has been done at 12 (60%) patients at the end of 6 month irrigating period. No changes of the ultrasonographic image of the precolostomic segment of colon has been observed.

  8. Magnetomotive colon elastography: preliminary assessment

    International Nuclear Information System (INIS)

    Bruno, A. Colello; Grillo, F.W.; Sampaio, D.R.T.; Carneiro, A.A.O.

    2015-01-01

    Colorectal cancer (CRC) is the third most common malignant neoplasm worldwide and early diagnosis reduces morbidity. The standard preventive exams methods are uncomfortable for the patient, invasive, and /or are ionizing. Here, we evaluate the potential of magneto-motive ultrasound (MMUS) as a new, minimally invasive CRC screening technique. We developed a hybrid transducer (comprised of an ultrasound probe and a magnetic coil system) to construct relative elastography maps in a paraffin phantom with isoechoic inclusions. The electromagnetic component of our system manipulated ferromagnetic fluid located inside of our synthetic colon, and the captured ultrasound images were used to produce relative elastography maps. The MMUS images reveal by otherwise invisible structures based on differences in stiffness. Ultrasound elastography (relative) images by MMUs technique complements usual preventive CRC exams, is minimally invasive, has relative low cost when compared with others image methods. Also is fast diagnose and more comfortable for patient which prevents withdrawal of the screening. (author)

  9. Life in the "plastisphere": microbial communities on plastic marine debris.

    Science.gov (United States)

    Zettler, Erik R; Mincer, Tracy J; Amaral-Zettler, Linda A

    2013-07-02

    Plastics are the most abundant form of marine debris, with global production rising and documented impacts in some marine environments, but the influence of plastic on open ocean ecosystems is poorly understood, particularly for microbial communities. Plastic marine debris (PMD) collected at multiple locations in the North Atlantic was analyzed with scanning electron microscopy (SEM) and next-generation sequencing to characterize the attached microbial communities. We unveiled a diverse microbial community of heterotrophs, autotrophs, predators, and symbionts, a community we refer to as the "Plastisphere". Pits visualized in the PMD surface conformed to bacterial shapes suggesting active hydrolysis of the hydrocarbon polymer. Small-subunit rRNA gene surveys identified several hydrocarbon-degrading bacteria, supporting the possibility that microbes play a role in degrading PMD. Some Plastisphere members may be opportunistic pathogens (the authors, unpublished data) such as specific members of the genus Vibrio that dominated one of our plastic samples. Plastisphere communities are distinct from surrounding surface water, implying that plastic serves as a novel ecological habitat in the open ocean. Plastic has a longer half-life than most natural floating marine substrates, and a hydrophobic surface that promotes microbial colonization and biofilm formation, differing from autochthonous substrates in the upper layers of the ocean.

  10. Early microbial contact, the breast milk microbiome and child health.

    Science.gov (United States)

    Rautava, S

    2016-02-01

    The significance of contact with microbes in early life for subsequent health has been the subject of intense research during the last 2 decades. Disturbances in the establishment of the indigenous intestinal microbiome caused by cesarean section delivery or antibiotic exposure in early life have been linked to the risk of immune-mediated and inflammatory conditions such as atopic disorders, inflammatory bowel disease and obesity later in life. Distinct microbial populations have recently been discovered at maternal sites including the amniotic cavity and breast milk, as well as meconium, which have previously been thought to be sterile. Our understanding of the impact of fetal microbial contact on health outcomes is still rudimentary. Breast milk is known to modulate immune and metabolic programming. The breast milk microbiome is hypothesized to guide infant gut colonization and is affected by maternal health status and mode of delivery. Immunomodulatory factors in breast milk interact with the maternal and infant gut microbiome and may mediate some of the health benefits associated with breastfeeding. The intimate connection between the mother and the fetus or the infant is a potential target for microbial therapeutic interventions aiming to support healthy microbial contact and protect against disease.

  11. Electric motor drive unit, especially adjustment drive for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Litterst, P

    1980-05-29

    An electric motor drive unit, particularly an adjustment drive for vehicles with at least two parallel drive shafts is described, which is compact and saves space, and whose manufacturing costs are low compared with those of well-known drive units of this type. The drive unit contains a suitable number of magnet systems, preferably permanent magnet systems, whose pole axes are spaced and run parallel. The two pole magnet systems have diametrically opposite shell-shaped segments, to which the poles are fixed. In at least one magnet system the two segments are connected by diametrically opposite flat walls parallel to the pole axes to form a single magnetic circuit pole housing. The segments of at least one other magnet system are arranged on this pole housing so that one of these flat walls is a magnetically conducting, connecting component of the magnetic circuit of the other magnet system.

  12. Colon and rectal cancer survival by tumor location and microsatellite instability: the Colon Cancer Family Registry.

    Science.gov (United States)

    Phipps, Amanda I; Lindor, Noralane M; Jenkins, Mark A; Baron, John A; Win, Aung Ko; Gallinger, Steven; Gryfe, Robert; Newcomb, Polly A

    2013-08-01

    Cancers in the proximal colon, distal colon, and rectum are frequently studied together; however, there are biological differences in cancers across these sites, particularly in the prevalence of microsatellite instability. We assessed the differences in survival by colon or rectal cancer site, considering the contribution of microsatellite instability to such differences. This is a population-based prospective cohort study for cancer survival. This study was conducted within the Colon Cancer Family Registry, an international consortium. Participants were identified from population-based cancer registries in the United States, Canada, and Australia. Information on tumor site, microsatellite instability, and survival after diagnosis was available for 3284 men and women diagnosed with incident invasive colon or rectal cancer between 1997 and 2002, with ages at diagnosis ranging from 18 to 74. Cox regression was used to calculate hazard ratios for the association between all-cause mortality and tumor location, overall and by microsatellite instability status. Distal colon (HR, 0.59; 95% CI, 0.49-0.71) and rectal cancers (HR, 0.68; 95% CI, 0.57-0.81) were associated with lower mortality than proximal colon cancer overall. Compared specifically with patients with proximal colon cancer exhibiting no/low microsatellite instability, patients with distal colon and rectal cancers experienced lower mortality, regardless of microsatellite instability status; patients with proximal colon cancer exhibiting high microsatellite instability had the lowest mortality. Study limitations include the absence of stage at diagnosis and cause-of-death information for all but a subset of study participants. Some patient groups defined jointly by tumor site and microsatellite instability status are subject to small numbers. Proximal colon cancer survival differs from survival for distal colon and rectal cancer in a manner apparently dependent on microsatellite instability status. These

  13. Functional patterns of microbial communities of rhizospheric soils across the development stages of a young mangrove in French Guiana.

    Science.gov (United States)

    Luglia, Mathieu; Criquet, Stéven; Sarrazin, Max; Ziarelli, Fabio; Guiral, Daniel

    2014-02-01

    The functional patterns of microbial communities (microbial respiration, enzyme activities, functional diversity) and the relevant physico-chemical characteristics of rhizospheric soils were studied during the process of mudflat colonization by mangrove. The study site is a fringe mangrove stand located in Montabo Bay at Cayenne (French Guiana). It is characterized by different vegetation development stages dominated by an assemblage of Avicennia germinans and Laguncularia racemosa. Rhizospheric and surface soils were collected from three stations based on successional stages of mangrove colonization: pioneer (P), coppice (C), and young forest (F). The microbial functional patterns showed significant progressive shifts along the mangrove vegetation profile. The P stages, those most influenced by tide currents, were macroscopically characterized by hydro-sedimentary instability and micro-phytobenthic colonization of mudflat. This stage, characterized by low total organic carbon (TOC) content and quality, showed the lowest extracellular enzymatic activities and the highest functional metabolic diversities. TOC quality analyses by (13)C CPMAS NMR provided evidence of progressive TOC enrichment and an increasing imprint of aboveground vegetation on C quality as succession occurs. These differences in the origin, amount, and quality of soil organic matter (SOM) of older stages exerted both a quantitative and qualitative control over microbial functional responses. This indicated the enhancement of aboveground-belowground functional linkages, leading to the expression of high decomposition activities and a functional loss and specialization of rhizospheric microbial communities.

  14. Microbial diversity and impact on carbonate geochemistry across a changing geochemical gradient in a karst aquifer.

    Science.gov (United States)

    Gray, Cassie J; Engel, Annette S

    2013-02-01

    Although microbes are known to influence karst (carbonate) aquifer ecosystem-level processes, comparatively little information is available regarding the diversity of microbial activities that could influence water quality and geological modification. To assess microbial diversity in the context of aquifer geochemistry, we coupled 16S rRNA Sanger sequencing and 454 tag pyrosequencing to in situ microcosm experiments from wells that cross the transition from fresh to saline and sulfidic water in the Edwards Aquifer of central Texas, one of the largest karst aquifers in the United States. The distribution of microbial groups across the transition zone correlated with dissolved oxygen and sulfide concentration, and significant variations in community composition were explained by local carbonate geochemistry, specifically calcium concentration and alkalinity. The waters were supersaturated with respect to prevalent aquifer minerals, calcite and dolomite, but in situ microcosm experiments containing these minerals revealed significant mass loss from dissolution when colonized by microbes. Despite differences in cell density on the experimental surfaces, carbonate loss was greater from freshwater wells than saline, sulfidic wells. However, as cell density increased, which was correlated to and controlled by local geochemistry, dissolution rates decreased. Surface colonization by metabolically active cells promotes dissolution by creating local disequilibria between bulk aquifer fluids and mineral surfaces, but this also controls rates of karst aquifer modification. These results expand our understanding of microbial diversity in karst aquifers and emphasize the importance of evaluating active microbial processes that could affect carbonate weathering in the subsurface.

  15. The Biogeographic Pattern of Microbial Functional Genes along an Altitudinal Gradient of the Tibetan Pasture

    Directory of Open Access Journals (Sweden)

    Qi Qi

    2017-06-01

    Full Text Available As the highest place of the world, the Tibetan plateau is a fragile ecosystem. Given the importance of microbial communities in driving soil nutrient cycling, it is of interest to document the microbial biogeographic pattern here. We adopted a microarray-based tool named GeoChip 4.0 to investigate grassland microbial functional genes along an elevation gradient from 3200 to 3800 m above sea level open to free grazing by local herdsmen and wild animals. Interestingly, microbial functional diversities increase with elevation, so does the relative abundances of genes associated with carbon degradation, nitrogen cycling, methane production, cold shock and oxygen limitation. The range of Shannon diversities (10.27–10.58 showed considerably smaller variation than what was previously observed at ungrazed sites nearby (9.95–10.65, suggesting the important role of livestock grazing on microbial diversities. Closer examination showed that the dissimilarity of microbial community at our study sites increased with elevations, revealing an elevation-decay relationship of microbial functional genes. Both microbial functional diversity and the number of unique genes increased with elevations. Furthermore, we detected a tight linkage of greenhouse gas (CO2 and relative abundances of carbon cycling genes. Our biogeographic study provides insights on microbial functional diversity and soil biogeochemical cycling in Tibetan pastures.

  16. The Biogeographic Pattern of Microbial Functional Genes along an Altitudinal Gradient of the Tibetan Pasture

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Qi; Zhao, Mengxin; Wang, Shiping; Ma, Xingyu; Wang, Yuxuan; Gao, Ying; Lin, Qiaoyan; Li, Xiangzhen; Gu, Baohua; Li, Guoxue; Zhou, Jizhong; Yang, Yunfeng

    2017-06-13

    As the highest place of the world, the Tibetan plateau is a fragile ecosystem. Given the importance of microbial communities in driving soil nutrient cycling, it is of interest to document the microbial biogeographic pattern here. We adopted a microarray-based tool named GeoChip 4.0 to investigate grassland microbial functional genes along an elevation gradient from 3200 to 3800 m above sea level open to free grazing by local herdsmen and wild animals. Interestingly, microbial functional diversities increase with elevation, so does the relative abundances of genes associated with carbon degradation, nitrogen cycling, methane production, cold shock and oxygen limitation. The range of Shannon diversities (10.27–10.58) showed considerably smaller variation than what was previously observed at ungrazed sites nearby (9.95–10.65), suggesting the important role of livestock grazing on microbial diversities. Closer examination showed that the dissimilarity of microbial community at our study sites increased with elevations, revealing an elevation-decay relationship of microbial functional genes. Both microbial functional diversity and the number of unique genes increased with elevations. Furthermore, we detected a tight linkage of greenhouse gas (CO2) and relative abundances of carbon cycling genes. Our biogeographic study provides insights on microbial functional diversity and soil biogeochemical cycling in Tibetan pastures.

  17. Flux analysis of the human proximal colon using anaerobic digestion model 1.

    Science.gov (United States)

    Motelica-Wagenaar, Anne Marieke; Nauta, Arjen; van den Heuvel, Ellen G H M; Kleerebezem, Robbert

    2014-08-01

    The colon can be regarded as an anaerobic digestive compartment within the gastro intestinal tract (GIT). An in silico model simulating the fluxes in the human proximal colon was developed on basis of the anaerobic digestion model 1 (ADM1), which is traditionally used to model waste conversion to biogas. Model calibration was conducted using data from in vitro fermentation of the proximal colon (TIM-2), and, amongst others, supplemented with the bio kinetics of prebiotic galactooligosaccharides (GOS) fermentation. The impact of water and solutes absorption by the host was also included. Hydrolysis constants of carbohydrates and proteins were estimated based on total short chain fatty acids (SCFA) and ammonia production in vitro. Model validation was established using an independent dataset of a different in vitro model: an in vitro three-stage continuous culture system. The in silico model was shown to provide quantitative insight in the microbial community structure in terms of functional groups, and the substrate and product fluxes between these groups as well as the host, as a function of the substrate composition, pH and the solids residence time (SRT). The model confirms the experimental observation that methanogens are washed out at low pH or low SRT-values. The in silico model is proposed as useful tool in the design of experimental setups for in vitro experiments by giving insight in fermentation processes in the proximal human colon. Copyright © 2014. Published by Elsevier Ltd.

  18. Free radical scavenging and COX-2 inhibition by simple colon metabolites of polyphenols: A theoretical approach.

    Science.gov (United States)

    Amić, Ana; Marković, Zoran; Marković, Jasmina M Dimitrić; Jeremić, Svetlana; Lučić, Bono; Amić, Dragan

    2016-12-01

    Free radical scavenging and inhibitory potency against cyclooxygenase-2 (COX-2) by two abundant colon metabolites of polyphenols, i.e., 3-hydroxyphenylacetic acid (3-HPAA) and 4-hydroxyphenylpropionic acid (4-HPPA) were theoretically studied. Different free radical scavenging mechanisms are investigated in water and pentyl ethanoate as a solvent. By considering electronic properties of scavenged free radicals, hydrogen atom transfer (HAT) and sequential proton loss electron transfer (SPLET) mechanisms are found to be thermodynamically probable and competitive processes in both media. The Gibbs free energy change for reaction of inactivation of free radicals indicates 3-HPAA and 4-HPPA as potent scavengers. Their reactivity toward free radicals was predicted to decrease as follows: hydroxyl>alkoxyls>phenoxyl≈peroxyls>superoxide. Shown free radical scavenging potency of 3-HPAA and 4-HPPA along with their high μM concentration produced by microbial colon degradation of polyphenols could enable at least in situ inactivation of free radicals. Docking analysis with structural forms of 3-HPAA and 4-HPPA indicates dianionic ligands as potent inhibitors of COX-2, an inducible enzyme involved in colon carcinogenesis. Obtained results suggest that suppressing levels of free radicals and COX-2 could be achieved by 3-HPAA and 4-HPPA indicating that these compounds may contribute to reduced risk of colon cancer development. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Butyrate and bioactive proteolytic form of Wnt-5a regulate colonic epithelial proliferation and spatial development

    Science.gov (United States)

    Uchiyama, Kazuhiko; Sakiyama, Toshio; Hasebe, Takumu; Musch, Mark W.; Miyoshi, Hiroyuki; Nakagawa, Yasushi; He, Tong-Chuan; Lichtenstein, Lev; Naito, Yuji; Itoh, Yoshito; Yoshikawa, Toshikazu; Jabri, Bana; Stappenbeck, Thaddeus; Chang, Eugene B.

    2016-01-01

    Proliferation and spatial development of colonic epithelial cells are highly regulated along the crypt vertical axis, which, when perturbed, can result in aberrant growth and carcinogenesis. In this study, two key factors were identified that have important and counterbalancing roles regulating these processes: pericrypt myofibroblast-derived Wnt-5a and the microbial metabolite butyrate. Cultured YAMC cell proliferation and heat shock protein induction were analzyed after butryate, conditioned medium with Wnt5a activity, and FrzB containing conditioned medium. In vivo studies to modulate Hsp25 employed intra-colonic wall Hsp25 encoding lentivirus. To silence Wnt-5a in vivo, intra-colonic wall Wnt-5a silencing RNA was used. Wnt-5a, secreted by stromal myofibroblasts of the lower crypt, promotes proliferation through canonical β-catenin activation. Essential to this are two key requirements: (1) proteolytic conversion of the highly insoluble ~40 kD Wnt-5a protein to a soluble 36 mer amino acid peptide that activates epithelial β-catenin and cellular proliferation, and (2) the simultaneous inhibition of butyrate-induced Hsp25 by Wnt-5a which is necessary to arrest the proliferative process in the upper colonic crypt. The interplay and spatial gradients of these factors insures that crypt epithelial cell proliferation and development proceed in an orderly fashion, but with sufficient plasticity to adapt to physiological perturbations including inflammation. PMID:27561676

  20. Necrotizing colitis associated with carcinoma of the colon

    International Nuclear Information System (INIS)

    Woo, Seong Ku; Lim, Jae Hoon; Kim, Soon Yong; Ahn, Chi Yul

    1982-01-01

    Necrotizing colitis associated with carcinoma of the colon, known also as obstructive colitis, is a disorder characterized by anulceration and inflammation of the colon proximal to an obstructive lesion, especially carcinoma of the rectosigmoid colon, and in rare instance, leads to acute gangrene of the colon. The authors analyzed radiologic findings in four cases of necrotizing colitis associated with carcinoma of the colon. Barium enema disclosed mucosal edema, nodular filling defects, irregularity of the colonic contour and typical thumbprinting appearance of involved colon proximal to an obstructing carcinoma of the colon. The mechanism of necrotizing colitis was briefly reviewed