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Sample records for epilithic periphyton communities

  1. Resource synergy in stream periphyton communities

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Walter [University of Illinois, Urbana-Champaign; Fanta, S.E. [University of Illinois; Roberts, Brian J [ORNL; Francoeur, Steven N. [Eastern Michigan University, Ypsilanti, MI

    2011-03-01

    1. Light and nutrients play pivotal roles in determining the growth of autotrophs, yet the potential for synergistic interactions between the two resources in algal communities is poorly understood, especially in stream ecosystems. In this study, light and phosphorus were manipulated in large experimental streams to examine resource colimitation and synergy in stream periphyton. 2. Whole-stream metabolism was simultaneously limited by light and phosphorus. Increasing the supply of either light or phosphorus resulted in significant increases in primary production and the transformation of the streams from heterotrophy to autotrophy. 3. Resource-driven changes in periphyton community structure occurred in concert with changes in production. Algal assemblages in highly shaded streams were composed primarily of small diatoms such as Achnanthidium minutissima, whereas larger diatoms such as Melosira varians predominated at higher irradiances. Phosphorus enrichment had relatively little effect on assemblage structure, but it did substantially diminish the abundance of Meridion circulare, a diatom whose mucilaginous colonies were conspicuously abundant in phosphorus-poor, high-light streams. Bacterial biomass declined relative to algal biomass with increases in primary productivity, regardless of whether the increases were caused by light or phosphorus. 4. Synergistic effects on primary production appeared to occur because the availability of one resource facilitated the utilization of the other. Light increased the abundance of large diatoms, which are known to convert high concentrations of nutrients into primary production more effectively than smaller taxa. Phosphorus enrichment led to the replacement of Meridion circulare by non-mucilaginous taxa in phosphorus-enriched streams, and we hypothesize that this change enabled more efficient use of light in photosynthesis. Higher ratios of chlorophyll a : biomass in phosphorus-enriched streams may have also led to more

  2. Impact of chronic and acute pesticide exposures on periphyton communities

    Energy Technology Data Exchange (ETDEWEB)

    Tlili, Ahmed, E-mail: ahmed.tlili@cemagref.fr [CEMAGREF, UR MAEP, 3 quai Chauveau CP 69336 Lyon Cedex 09 (France); Montuelle, Bernard, E-mail: bernard.montuelle@cemagref.fr [CEMAGREF, UR MAEP, 3 quai Chauveau CP 69336 Lyon Cedex 09 (France); INRA UMR CARRTEL, Laboratoire de Microbiologie Aquatique, BP 511, 74203, Thonon Cedex (France); Berard, Annette, E-mail: annette.berard@avignon.inra.fr [INRA UMR EMMAH 1114, Domaine Saint-Paul-Site Agroparc 84914 Avignon Cedex 9 (France); Bouchez, Agnes, E-mail: agnes.bouchez@thonon.inra.fr [INRA UMR CARRTEL, Laboratoire de Microbiologie Aquatique, BP 511, 74203, Thonon Cedex (France)

    2011-05-01

    Aquatic ecosystems face variable exposure to pesticides, especially during floodings which are associated with short bursts of high contaminant concentrations that influence biological systems. A study was undertaken to highlight the impact of the herbicide diuron applied in mixture with the fungicide tebuconazole on natural periphyton during flooding events. Periphyton were grown in two series of two lotic outdoor mesocosms: one series was non-contaminated while the other was exposed to chronic contamination. After 4 weeks, one channel of each series was exposed to three successive pulses, with each pulse followed by one week of recovery. Impacts on periphyton were assessed by using Denaturing Gel Gradient Electrophoresis to characterize eukaryotic community structure. At a functional scale, photosynthetic efficiency was quantified during each pulse, and the induced tolerance to diuron was estimated by performing short-term inhibition tests based on photosynthetic efficiency. Moreover, pesticide concentrations in the water column and periphyton matrix were measured. Diuron was adsorbed in the periphyton during each pulse and desorbed 13 h after pulse end. The different pulses affected the eukaryotic community structures of the control biofilms, but not of the chronically exposed ones. During the first pulse, photosynthetic efficiency was correlated with pesticide concentration in the water phase, and there was no difference between periphyton from chronically contaminated channels and control channels. However, during the second and third pulses, the photosynthetic efficiency of periphyton chronically exposed to pesticides appeared to be less impacted by the acute pulsed exposure of pesticide. These changes were consistent with the acquisition of induced tolerance to diuron since only after the third pulse that periphyton from chronic channel became tolerant to diuron. Our experimental study indicates that the effects of pulsed acute exposures to pesticides on

  3. Impact of chronic and acute pesticide exposures on periphyton communities

    International Nuclear Information System (INIS)

    Tlili, Ahmed; Montuelle, Bernard; Berard, Annette; Bouchez, Agnes

    2011-01-01

    Aquatic ecosystems face variable exposure to pesticides, especially during floodings which are associated with short bursts of high contaminant concentrations that influence biological systems. A study was undertaken to highlight the impact of the herbicide diuron applied in mixture with the fungicide tebuconazole on natural periphyton during flooding events. Periphyton were grown in two series of two lotic outdoor mesocosms: one series was non-contaminated while the other was exposed to chronic contamination. After 4 weeks, one channel of each series was exposed to three successive pulses, with each pulse followed by one week of recovery. Impacts on periphyton were assessed by using Denaturing Gel Gradient Electrophoresis to characterize eukaryotic community structure. At a functional scale, photosynthetic efficiency was quantified during each pulse, and the induced tolerance to diuron was estimated by performing short-term inhibition tests based on photosynthetic efficiency. Moreover, pesticide concentrations in the water column and periphyton matrix were measured. Diuron was adsorbed in the periphyton during each pulse and desorbed 13 h after pulse end. The different pulses affected the eukaryotic community structures of the control biofilms, but not of the chronically exposed ones. During the first pulse, photosynthetic efficiency was correlated with pesticide concentration in the water phase, and there was no difference between periphyton from chronically contaminated channels and control channels. However, during the second and third pulses, the photosynthetic efficiency of periphyton chronically exposed to pesticides appeared to be less impacted by the acute pulsed exposure of pesticide. These changes were consistent with the acquisition of induced tolerance to diuron since only after the third pulse that periphyton from chronic channel became tolerant to diuron. Our experimental study indicates that the effects of pulsed acute exposures to pesticides on

  4. Interaction between local hydrodynamics and algal community in epilithic biofilm.

    Science.gov (United States)

    Graba, Myriam; Sauvage, Sabine; Moulin, Frédéric Y; Urrea, Gemma; Sabater, Sergi; Sanchez-Pérez, José Miguel

    2013-05-01

    Interactions between epilithic biofilm and local hydrodynamics were investigated in an experimental flume. Epilithic biofilm from a natural river was grown over a 41-day period in three sections with different flow velocities (0.10, 0.25 and 0.40 m s(-1) noted LV, IV and HV respectively). Friction velocities u* and boundary layer parameters were inferred from PIV measurement in the three sections and related to the biofilm structure. The results show that there were no significant differences in Dry Mass and Ash-Free Dry Mass (g m(-2)) at the end of experiment, but velocity is a selective factor in algal composition and the biofilms' morphology differed according to differences in water velocity. A hierarchical agglomerative cluster analysis (Bray-Curtis distances) and an Indicator Species Analysis (IndVal) showed that the indicator taxa were Fragilaria capucina var. mesolepta in the low-velocity (u*. = 0.010-0.012 m s(-1)), Navicula atomus, Navicula capitatoradiata and Nitzschia frustulum in the intermediate-velocity (u*. = 0.023-0.030 m s(-1)) and Amphora pediculus, Cymbella proxima, Fragilaria capucina var. vaucheriae and Surirella angusta in the high-velocity (u*. = 0.033-0.050 m s(-1)) sections. A sloughing test was performed on 40-day-old biofilms in order to study the resistance of epilithic biofilms to higher hydrodynamic regimes. The results showed an inverse relationship between the proportion of detached biomass and the average value of friction velocity during growth. Therefore, water velocity during epilithic biofilm growth conditioned the structure and algal composition of biofilm, as well as its response (ability to resist) to higher shear stresses. This result should be considered in modelling epilithic biofilm dynamics in streams subject to a variable hydrodynamics regime. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Epilithic and endolithic bacterial communities in limestone from a Maya archaeological site.

    Science.gov (United States)

    McNamara, Christopher J; Perry, Thomas D; Bearce, Kristen A; Hernandez-Duque, Guillermo; Mitchell, Ralph

    2006-01-01

    Biodeterioration of archaeological sites and historic buildings is a major concern for conservators, archaeologists, and scientists involved in preservation of the world's cultural heritage. The Maya archaeological sites in southern Mexico, some of the most important cultural artifacts in the Western Hemisphere, are constructed of limestone. High temperature and humidity have resulted in substantial microbial growth on stone surfaces at many of the sites. Despite the porous nature of limestone and the common occurrence of endolithic microorganisms in many habitats, little is known about the microbial flora living inside the stone. We found a large endolithic bacterial community in limestone from the interior of the Maya archaeological site Ek' Balam. Analysis of 16S rDNA clones demonstrated disparate communities (endolithic: >80% Actinobacteria, Acidobacteria, and Low GC Firmicutes; epilithic: >50% Proteobacteria). The presence of differing epilithic and endolithic bacterial communities may be a significant factor for conservation of stone cultural heritage materials and quantitative prediction of carbonate weathering.

  6. Toxic effects of isoproturon on periphyton communities a microcosm study

    Science.gov (United States)

    Schmitt-Jansen, Mechthild; Altenburger, Rolf

    2005-02-01

    Coastal and estuarine ecosystems are increasingly exposed to herbicide contamination. To study the potential risks of these pollutants, the establishment of periphyton communities under exposure of a concentration series of isoproturon in a range of 0.0024-0.312 mg L -1 was investigated in a microcosm study. After two weeks of growth, chronic effects on biomass development, measured as Chl a fluorescence, taxonomic composition and photosynthetic capacity of PS II of attached microalgae were analysed using a pulse-amplitude modulated (PAM) fluorescence-based method. Algal classes were differentiated according to their pigment systems using four excitation wavelengths. Biomass remained constant up to pre-exposure concentrations of 0.02 mg L -1 isoproturon but decreased within one order of magnitude at the highest test concentration. Algal classes shifted from diatoms to chlorophytes at pre-exposure concentrations of 0.02-0.39 mg L -1. Community structure of diatoms representing the dominant group of attached algae at lower test concentrations was studied by microscopic analysis revealing that species numbers were highest at lowest test concentrations as compared to controls. At higher test concentrations Navicula halophila dominated with 89% of the diatom biomass but was abnormally shaped. Pollution-induced community tolerance (PICT) of periphyton to isoproturon was determined by short-term inhibition tests of photosynthesis. Pre-exposed communities increased their effect concentrations (EC 50) up to threefold within the 0.039 mg L -1 pre-treatment. Our results suggest that attached microalgal communities have a high potential of tolerance development to isoproturon at lower levels of contamination due to the replacement of sensitive species by more tolerant algae, although these species seemed to be affected too. We conclude that herbicide concentrations in river basins, estuaries or coastal zones may change community structure and primary production of

  7. Diffusive boundary layers and photosynthesis of the epilithic algal community of coral reefs

    DEFF Research Database (Denmark)

    Larkum, Anthony W.D.; Koch, Eva-Maria W.; Kühl, Michael

    2003-01-01

    The effects of mass transfer resistance due to the presence of a diffusive boundary layer on the photosynthesis of the epilithic algal community (EAC) of a coral reef were studied. Photosynthesis and respiration of the EAC of dead coral surfaces were investigated for samples from two locations......: the Gulf of Aqaba, Eilat (Israel), and One Tree Reef on the Great Barrier Reef (Australia). Microsensors were used to measure O2 and pH at the EAC surface and above. Oxygen profiles in the light and dark indicated a diffusive boundary layer (DBL) thickness of 180–590 µm under moderate flow (~0.08 m s-1...

  8. Metagenomic Sequencing of Marine Periphyton: Taxonomic and Functional Insights into Biofilm Communities

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    Kemal eSanli

    2015-10-01

    Full Text Available Periphyton communities are complex phototrophic, multispecies biofilms that develop on surfaces in aquatic environments. These communities harbor a large diversity of organisms comprising viruses, bacteria, algae, fungi, protozoans and metazoans. However, thus far the total biodiversity of periphyton has not been described. In this study, we use metagenomics to characterize periphyton communities from the marine environment of the Swedish west coast. Although we found approximately ten times more eukaryotic rRNA marker gene sequences compared to prokaryotic, the whole metagenome-based similarity searches showed that bacteria constitute the most abundant phyla in these biofilms. We show that marine periphyton encompass a range of heterotrophic and phototrophic organisms. Heterotrophic bacteria, including the majority of proteobacterial clades and Bacteroidetes, and eukaryotic macro-invertebrates were found to dominate periphyton. The phototrophic groups comprise Cyanobacteria and the alpha-proteobacterial genus Roseobacter, followed by different micro- and macro-algae. We also assess the metabolic pathways that predispose these communities to an attached lifestyle. Functional indicators of the biofilm form of life in periphyton involve genes coding for enzymes that catalyze the production and degradation of extracellular polymeric substances, mainly in the form of complex sugars such as starch and glycogen-like meshes together with chitin. Genes for 278 different transporter proteins were detected in the metagenome, constituting the most abundant protein complexes. Finally, genes encoding enzymes that participate in anaerobic pathways, such as denitrification and methanogenesis, were detected suggesting the presence of anaerobic or low-oxygen micro-zones within the biofilms.

  9. Effects of different levels of UV-B radiation on marine epilithic communities: a short-term microcosm study

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    R. A. Danilov

    2000-12-01

    Full Text Available Epilithic communities from brackish coastal water of the east coast of Sweden were studied in order to reveal their responses to different levels of UV-B radiation. The experiment was conducted for seven days in an indoor microcosm system. The epilithic communities were exposed daily to different doses of UV-B radiation: 1, 3, 5 and 7 hours, respectively. The intensity of the UV-B radiation used was similar to that in natural environments. After seven days clear shifts both in species composition and community structure were observed. All species of diatoms showed negative correlation with enhanced levels of UV-B. On the other hand, abundance of cyanobacteria was positively correlated with enhanced levels of UV-B (Calothrix aeruginea, R=0.49;Oscillatoria amphibia, R=0.93; Pseudanabaena mucicola, R=0.26. Communities dominated by diatoms and green algae at the initial stage of the experiment did show a drastic decrease in diatom abundance under UV-B stress and finally became dominated by cyanobacteria. Among green algae the abundance of Cladophora sericea correlated positively (R=0.33 with enhanced exposure to UV-B, while Monoraphidium-species exhibited negative correlation to UV-B. Otherwise, no significant correlation between other green algae species identified and UV-B stress could be detected. We conclude that UV-B radiation, even at lower levels, is capable to induce severe changes to marine epilithic communities. The trends revealed in the present study predict a shift from communities dominated by diatoms and green algae to those dominated by cyanobacteria.

  10. Epilithic lichens in rock communities on the territory of the Botanical Garden of PetrSU

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    Serapionova Olesya

    2017-12-01

    Full Text Available Species diversity of epilithic lichens (54 species on the territory of the Botanical Garden of Petrozavodsk State University with different character of anthropogenic impact has been reported. Nine species of epilithic lichens are recorded as new for the studied territory and species Acarospora nitrophila, Lecanora sulphurea, Lecidea lithophila - as new for the biogeographical province of Karelia onegensis. The highest number of lichen species was found within area of observation deck “Devil's chair” where the greatest variety of microhabitats was presented.

  11. Effect of substrate on periphyton communities and relationships among food web components in shallow hypertrophic lake

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    Tomasz Mieczan

    2012-07-01

    Full Text Available We studied the role of natural (common reed and artificial substrata (bamboo in structuring the abundance and taxonomic composition of periphyton assemblages. Investigations were conducted in a shallow, hypertrophic lake situated in the area of Polesie Lubelskie (Eastern Poland. Periphyton communities (algae, ciliates, small metazoa and chironomids on both types of substratum were sampled monthly, from May to November of 2007. Water samples for chemical analysis were collected together with biological samples. We selected the group of ten environmental variables which are the most important in determining the habitat conditions in highly eutrophic lakes: temperature, Secchi disc visibility, conductivity, dissolved oxygen, periphytic chlorophyll-a, N-NO3, N-NH4, TP, P-PO4 and total organic carbon (TOC. The abundances of periphytic algae, ciliates, metazoa and chironomids were significantly affected by season and substrate. On natural substrata, in all studied months, periphyton communities showed higher abundances. The results of PCA analysis confirmed the distinction between periphyton communities on natural and artificial substrata. The Monte Carlo permutation test showed that the periphyton communities on common reed were the most significantly affected by temperature, N-NO3, Secchi disc visibility and TOC. The communities on artificial substrata were significantly influenced by temperature, P-PO4 and TOC. On natural substrata biomass of periphytic algae was significantly negatively correlated with abundances of all groups of potential grazers (ciliates, metazoa, chironomids. On artificial substrata the relations between components of periphytic food web were stronger; correlation coefficients between algae, protists and chironomids were significant at P<0.01. The results of analysis indicate that periphytic algae can play an important role as food source for higher trophic levels. These interactions are less significant on natural (reed

  12. Effect of a dam on epilithic algal communities of a mountain stream: before-after dam construction comparison

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    Luciana Cibils Martina

    2013-02-01

    Full Text Available In this study we evaluated the effect of a dam on epilithic algal communities by analyzing community response after dam construction and by comparing community composition, structure and biomass upstream and downstream of the dam. Samples of epilithic algae and environmental data were collected at each site during high and low water periods before and after dam construction in Achiras Stream (Córdoba, Argentina. Ordinations showed modifications in algal assemblages after dam construction and downstream of the dam. Ordinations also suggested a loss of seasonality at the downstream site since the assemblages were similar between hydrological periods after dam construction. Indicator species, obtained by the Indicator Value method, showed that, after dam construction, there could have been an increase in nutrient concentration and a release of plankton from the impoundment. Abundance, richness and diversity were altered after dam construction as assessed by ANOVAs derived from a modified BACI Design. Proportion of early-successional species was higher at the upstream site while late-successional species were dominant at the downstream site, as predicted. Lower fluctuations in discharge downstream of the dam may have helped succession advance, whereas at the upstream site, mainly during the high water period, floods could have caused sloughing of life forms from the outer layers of the biofilm, resetting the algal community to early successional stages. It may be concluded that the dam affected algal community and favored succession advance mainly by reducing current velocity and flow fluctuations.

  13. Interactive effects of ocean acidification and warming on coral reef associated epilithic algal communities under past, present-day and future ocean conditions

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    Vogel, N.; Cantin, N. E.; Strahl, J.; Kaniewska, P.; Bay, L.; Wild, C.; Uthicke, S.

    2016-06-01

    Epilithic algal communities play critical ecological roles on coral reefs, but their response to individual and interactive effects of ocean warming (OW) and ocean acidification (OA) is still largely unknown. We investigated growth, photosynthesis and calcification of early epilithic algal community assemblages exposed for 6 months to four temperature profiles (-1.1, ±0.0, +0.9, +1.6 °C) that were crossed with four carbon dioxide partial pressure (pCO2) levels (360, 440, 650, 940 µatm), under flow-through conditions and natural light regimes. Additionally, we compared the cover of heavily calcified crustose coralline algae (CCA) and lightly calcified red algae of the genus Peyssonnelia among treatments. Increase in cover of epilithic communities showed optima under moderately elevated temperatures and present pCO2, while cover strongly decreased under high temperatures and high-pCO2 conditions, particularly due to decreasing cover of CCA. Similarly, community calcification rates were strongly decreased at high pCO2 under both measured temperatures. While final cover of CCA decreased under high temperature and pCO2 (additive negative effects), cover of Peyssonnelia spp. increased at high compared to annual average and moderately elevated temperatures. Thus, cover of Peyssonnelia spp. increased in treatment combinations with less CCA, which was supported by a significant negative correlation between organism groups. The different susceptibility to stressors most likely derived from a different calcification intensity and/or mineral. Notably, growth of the epilithic communities and final cover of CCA were strongly decreased under reduced-pCO2 conditions compared to the present. Thus, CCA may have acclimatized from past to present-day pCO2 conditions, and changes in carbonate chemistry, regardless in which direction, negatively affect them. However, if epilithic organisms cannot further acclimatize to OW and OA, the interacting effects of both factors may change

  14. Epilithic Cyanobacterial Communities of a Marine Tropical Beach Rock (Heron Island, Great Barrier Reef): Diversity and Diazotrophy▿

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    Díez, Beatriz; Bauer, Karolina; Bergman, Birgitta

    2007-01-01

    The diversity and nitrogenase activity of epilithic marine microbes in a Holocene beach rock (Heron Island, Great Barrier Reef, Australia) with a proposed biological calcification “microbialite” origin were examined. Partial 16S rRNA gene sequences from the dominant mat (a coherent and layered pink-pigmented community spread over the beach rock) and biofilms (nonstratified, differently pigmented microbial communities of small shallow depressions) were retrieved using denaturing gradient gel electrophoresis (DGGE), and a clone library was retrieved from the dominant mat. The 16S rRNA gene sequences and morphological analyses revealed heterogeneity in the cyanobacterial distribution patterns. The nonheterocystous filamentous genus Blennothrix sp., phylogenetically related to Lyngbya, dominated the mat together with unidentified nonheterocystous filaments of members of the Pseudanabaenaceae and the unicellular genus Chroococcidiopsis. The dominance and three-dimensional intertwined distribution of these organisms were confirmed by nonintrusive scanning microscopy. In contrast, the less pronounced biofilms were dominated by the heterocystous cyanobacterial genus Calothrix, two unicellular Entophysalis morphotypes, Lyngbya spp., and members of the Pseudanabaenaceae family. Cytophaga-Flavobacterium-Bacteroides and Alphaproteobacteria phylotypes were also retrieved from the beach rock. The microbial diversity of the dominant mat was accompanied by high nocturnal nitrogenase activities (as determined by in situ acetylene reduction assays). A new DGGE nifH gene optimization approach for cyanobacterial nitrogen fixers showed that the sequences retrieved from the dominant mat were related to nonheterocystous uncultured cyanobacterial phylotypes, only distantly related to sequences of nitrogen-fixing cultured cyanobacteria. These data stress the occurrence and importance of nonheterocystous epilithic cyanobacteria, and it is hypothesized that such epilithic cyanobacteria

  15. Diel changes in stream periphyton extracellular enzyme activity throughout community development on inert and organic substrates

    Science.gov (United States)

    Rier, S. T.; Francoeur, S. N.; Kuehn, K. A.

    2005-05-01

    We tested the hypothesis that algal photosynthesis in stream periphyton communities would influence the activities of extracellular enzymes produced by associated heterotrophic bacteria and fungi to acquire organic compounds and inorganic nutrients. We approached this question by looking for diurnal variation in activities of four extracellular enzymes in periphyton communities that were grown on either inert (glass fiber filters) or organic (leaves) substrata that there were incubated in stream-side channels that were either open to full sun or shaded. Substrata were subsampled for β-glucosidase, alkaline phosphotase, leucine-aminopeptidase, and phenol oxidase activities at 3-5 hr. intervals over two consecutive diurnal cycles that were repeated at an early and later stage of periphyton community development. Activities of all enzymes displayed diurnal periodicity but the strength of the diurnal effects depended largely on the substrate type and stage of community development. The most consistent diurnal change was observed with phenol oxidase activity with significantly greater (p<0.05) activities being observed in during the day for both stages of community development and for both substrate types. It is likely that oxygen produced by algal photosynthesis is driving the activity of this oxidative enzyme and that algae might indirectly influence the decomposition of phenolic compounds.

  16. Twenty-eight Days to a Climax community: A Succession Laboratory Using Periphyton

    Science.gov (United States)

    Denicola, D. M.

    2005-05-01

    Succession in benthic algal communities (periphyton) occurs in a relatively short time scale because of the rapid reproductive rates of algae. To examine primary succession of periphyton in a lake and stream, unglazed tiles are placed in the respective habitats and sampled on days 4, 8, 16 and 28. Students count the preserved samples at 400X and identify taxa to genera based on customized picture keys (does not require a high degree of instructor expertise). Genera also are categorized according to algal growth forms, based on the size, shape, motility and attachment mechanism. After pooling the class data, students present the change in community structure, contrast succession between the lake and stream, and hypothesize which mechanisms may apply (facilitation, inhibition, tolerance). Successional sequences also are examined to see whether they agree with published growth form models for periphyton succession in lotic and lentic habitats. The laboratory uses the more intuitive method of repeated measures to study succession as an alternative to the often infeasible chronosequence method traditionally done for terrestrial communities. Additional outcomes include, reinforcement of the concept of species guilds (growth forms), an introduction into the use of empirical models, and an increased awareness of microorganism communities.

  17. Effects of Cr III and Pb on the bioaccumulation and toxicity of Cd in tropical periphyton communities: Implications of pulsed metal exposures

    International Nuclear Information System (INIS)

    Bere, Taurai; Chia, Mathias Ahii; Tundisi, José Galizia

    2012-01-01

    Metal exposure pattern, timing, frequency, duration, recovery period, metal type and interactions, has obscured effects on periphyton communities in lotic systems. The objective of this study was to investigate the effects of intermittent exposures of Cr III and Pb on Cd toxicity and bioaccumulation in tropical periphyton communities. Natural periphyton communities were transferred to artificial stream chambers and exposed to metal mixtures at different pulse timing, duration, frequency and recovery periods. Chlorophyll a, dry mass and metal accumulation kinetics were recorded. Cr and Pb decrease the toxic effects of Cd on periphyton communities. Periphyton has high Cd, Cr and Pb accumulation capacity. Cr and Pb reduced the levels of Cd sequestrated by periphyton communities. The closer the frequency and duration of the pulse is to a continuous exposure, the greater the effects of the contaminant on periphyton growth and metal bioaccumulation. Light increased toxic and accumulative effects of metals on the periphyton community. - Highlights: ► We investigated toxicity effects of pulsed metal exposures on bioaccumulation and toxicity in periphyton. ► High frequency of short duration pulses has effects equal to long duration exposures. ► Important role of light in modulating metal toxicity on periphyton demonstrated. ► Factors other than magnitude and duration must be considered in water quality criteria. ► Accurate prediction of metal effects on biofilms requires data on effluent variability. - The study highlights the importance of pulse timing, frequency, duration, recovery period and chemical type on aquatic life.

  18. Preliminary evaluation of an in vivo fluorometer to quantify algal periphyton biomass and community composition

    Science.gov (United States)

    Harris, Theodore D.; Graham, Jennifer L.

    2015-01-01

    The bbe-Moldaenke BenthoTorch (BT) is an in vivo fluorometer designed to quantify algal biomass and community composition in benthic environments. The BT quantifies total algal biomass via chlorophyll a (Chl-a) concentration and may differentiate among cyanobacteria, green algae, and diatoms based on pigment fluorescence. To evaluate how BT measurements of periphytic algal biomass (as Chl-a) compared with an ethanol extraction laboratory analysis, we collected BT- and laboratory-measured Chl-a data from 6 stream sites in the Indian Creek basin, Johnson County, Kansas, during August and September 2012. BT-measured Chl-a concentrations were positively related to laboratory-measured concentrations (R2 = 0.47); sites with abundant filamentous algae had weaker relations (R2 = 0.27). Additionally, on a single sample date, we used the BT to determine periphyton biomass and community composition upstream and downstream from 2 wastewater treatment facilities (WWTF) that discharge into Indian Creek. We found that algal biomass increased immediately downstream from the WWTF discharge then slowly decreased as distance from the WWTF increased. Changes in periphyton community structure also occurred; however, there were discrepancies between BT- and laboratory-measured community composition data. Most notably, cyanobacteria were present at all sites based on BT measurements but were present at only one site based on laboratory-analyzed samples. Overall, we found that the BT compared reasonably well with laboratory methods for relative patterns in Chl-a but not as well with absolute Chl-aconcentrations. Future studies need to test the BT over a wider range of Chl-aconcentrations, in colored waters, and across various periphyton assemblages.

  19. Summer periphyton community in two streams of the Pampa Plain, Argentina

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    Esquius Karina Soledad

    2011-11-01

    Full Text Available During summer 2001, periphytic algae associated to the giant bulrush Schoenoplectus californicus (Cyperaceae were studied in Los Padres and La Tapera streams (Pampa Plain, Argentina. One hundred and seven taxa were determined, being 76 of them common to both sampling sites. Diversity, total number of taxa and abundance of periphytic algae were greater in stems from the effl uent (La Tapera Stream. Diatoms were the most important group in both streams, according to their richness and abundance. Periphyton from the infl uent (Los Padres Stream was characterized by the dominance of the diatom Navicula cryptocephala and the codominance of another three algae. In contrast in La Tapera Stream, not any species could be recognized as dominant. Periphyton community architecture was more complex in the effl uent, with a high development of fi ve physiognomic groups. In conclusion, algal community attached to S. californicus differs in terms of diversity, abundance and community complexity, possibly due to the diffe rences registered in certain abiotic parameters, mainly in water transparency and velocity.

  20. Sampler collection gadget for epilithic diatoms.

    Science.gov (United States)

    Salomoni, S E; Torgan, L C; Rocha, O

    2007-11-01

    This work present a new gadget for sampling epilithic diatoms from both lentic and lotic enviroments. The sampler consists of a polystyrene cylinder, left to float on the surface of the water, to which stone substrates are attached. This epilithic diatom sampler (EDS) can be used to detect spatial and temporal richness and density variation in the study of the diatom community, as well as in water quality monitoring.

  1. Sampler collection gadget for epilithic diatoms

    Directory of Open Access Journals (Sweden)

    SE. Salomoni

    Full Text Available This work present a new gadget for sampling epilithic diatoms from both lentic and lotic enviroments. The sampler consists of a polystyrene cylinder, left to float on the surface of the water, to which stone substrates are attached. This epilithic diatom sampler (EDS can be used to detect spatial and temporal richness and density variation in the study of the diatom community, as well as in water quality monitoring.

  2. Oxygen dynamics in periphyton communities and associated effects on phosphorus release from lake sediments

    International Nuclear Information System (INIS)

    Carlton, R.G.

    1986-01-01

    Periphyton is typically a heterogeneous assemblage of filamentous and single celled photoautotrophic and heterotrophic micoorganisms suspended in a mucopolysaccharide matrix which they produce. By definition, the assemblage is attached to a substratum such as rock, sediment, or plant in an aquatic environment. Microtechniques with high spatial and temporal resolution are required to define metabolic interactions among the heterotrophic and autotrophic constituents, and between periphyton and its environment. This study used oxygen sensitive microelectrodes with tip diameters of 32 P radiotracer and that permitted manipulation of the velocity, flushing rate, and oxygen concentration of overlying water was developed to investigate the role of photosynthetic oxygen production on the phosphorus dynamics in lake sediments colonized by epipelic periphyton. 89 refs., 20 figs

  3. Analysis on biomass and productivity of epilithic algae and their relations to environmental factors in the Gufu River basin, Three Gorges Reservoir area, China.

    Science.gov (United States)

    Ge, Jiwen; Wu, Shuyuan; Touré, Dado; Cheng, Lamei; Miao, Wenjie; Cao, Huafen; Pan, Xiaoying; Li, Jianfeng; Yao, Minmin; Feng, Liang

    2017-12-01

    The main purpose of this study conducted from August 2010 was to find biomass and productivity of epilithic algae and their relations to environmental factors and try to explore the restrictive factors affecting the growth of algae in the Gufu River, the one of the branches of Xiangxi River located in the Three Gorges Reservoir of the Yangtze River, Hubei Province, Central China. An improved method of in situ primary productivity measurement was utilized to estimate the primary production of the epilithic algae. It was shown that in rivers, lakes, and reservoirs, algae are the main primary producers and have a central role in the ecosystem. Chlorophyll a concentration and ash-free dry mass (AFDM) were estimated for epilithic algae of the Gufu River basin in Three Gorges Reservoir area. Environmental factors in the Gufu River ecosystem highlighted differences in periphyton chlorophyll a ranging from 1.49 mg m -2 (origin) to 69.58 mg m -2 (terminal point). The minimum and maximum gross primary productivity of epilithic algae were 96.12 and 1439.89 mg C m -2  day -1 , respectively. The mean net primary productivity was 290.24 mg C m -2  day -1 . The mean autotrophic index (AFDM:chlorophyll a) was 407.40. The net primary productivity, community respiration ratio (P/R ratio) ranged from 0.98 to 9.25 with a mean of 2.76, showed that autotrophic productivity was dominant in the river. Relationship between physicochemical characteristics and biomass was discussed through cluster and stepwise regression analysis which indicated that altitude, total nitrogen (TN), NO 3 - -N, and NH 4 + -N were significant environmental factors affecting the biomass of epilithic algae. However, a negative logarithmic relationship between altitude and the chlorophyll a of epilithic algae was high. The results also highlighted the importance of epilithic algae in maintaining the Gufu River basin ecosystems health.

  4. High bacterial diversity in epilithic biofilms of oligotrophic mountain lakes.

    Science.gov (United States)

    Bartrons, Mireia; Catalan, Jordi; Casamayor, Emilio O

    2012-11-01

    Benthic microbial biofilms attached to rocks (epilithic) are major sites of carbon cycling and can dominate ecosystem primary production in oligotrophic lakes. We studied the bacterial community composition of littoral epilithic biofilms in five connected oligotrophic high mountain lakes located at different altitudes by genetic fingerprinting and clone libraries of the 16S rRNA gene. Different intra-lake samples were analyzed, and consistent changes in community structure (chlorophyll a and organic matter contents, and bacterial community composition) were observed along the altitudinal gradient, particularly related with the location of the lake above or below the treeline. Epilithic biofilm genetic fingerprints were both more diverse among lakes than within lakes and significantly different between montane (below the tree line) and alpine lakes (above the tree line). The genetic richness in the epilithic biofilm was much higher than in the plankton of the same lacustrine area studied in previous works, with significantly idiosyncratic phylogenetic composition (specifically distinct from lake plankton or mountain soils). Data suggest the coexistence of aerobic, anaerobic, phototrophic, and chemotrophic microorganisms in the biofilm, Bacteroidetes and Cyanobacteria being the most important bacterial taxa, followed by Alpha-, Beta-, Gamma-, and Deltaproteobacteria, Chlorobi, Planctomycetes, and Verrucomicrobia. The degree of novelty was especially high for epilithic Bacteroidetes, and up to 50 % of the sequences formed monophyletic clusters distantly related to any previously reported sequence. More than 35 % of the total sequences matched at <95 % identity to any previously reported 16S rRNA gene, indicating that alpine epilithic biofilms are unexplored habitats that contain a substantial degree of novelty within a short geographical distance. Further research is needed to determine whether these communities are involved in more biogeochemical pathways than

  5. Relation of periphyton and benthic invertebrate communities to environmental factors and land use at selected sites in part of the upper Mississippi River basin, 1996-98

    Science.gov (United States)

    ZumBerge, Jeremy Ryan; Lee, Kathy E.; Goldstein, Robert M.

    2003-01-01

    The Upper Mississippi River Basin is one of the hydrologic systems selected for study by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey. NAWQA utilizes a multi-disciplinary approach to explain factors that affect water quality. Part of the NAWQA design addresses the relation of land use and environmental factors to periphyton and benthic invertebrate communities in streams.

  6. Antarctic Epilithic Lichens as Niches for Black Meristematic Fungi

    Directory of Open Access Journals (Sweden)

    Laura Zucconi

    2013-05-01

    Full Text Available Sixteen epilithic lichen samples (13 species, collected from seven locations in Northern and Southern Victoria Land in Antarctica, were investigated for the presence of black fungi. Thirteen fungal strains isolated were studied by both morphological and molecular methods. Nuclear ribosomal 18S gene sequences were used together with the most similar published and unpublished sequences of fungi from other sources, to reconstruct an ML tree. Most of the studied fungi could be grouped together with described or still unnamed rock-inhabiting species in lichen dominated Antarctic cryptoendolithic communities. At the edge of life, epilithic lichens withdraw inside the airspaces of rocks to find conditions still compatible with life; this study provides evidence, for the first time, that the same microbes associated to epilithic thalli also have the same fate and chose endolithic life. These results support the concept of lichens being complex symbiotic systems, which offer attractive and sheltered habitats for other microbes.

  7. Diversity and biomineralization potential of the epilithic bacterial communities inhabiting the oldest public stone monument of Cluj-Napoca (Transylvania, Romania)

    Czech Academy of Sciences Publication Activity Database

    Andrei, Adrian-Stefan; Pausan, M.R.; Tamas, T.; Har, N.; Barbu-Tudoran, L.; Leopold, N.; Banciu, H.L.

    2017-01-01

    Roč. 8, March (2017), č. článku 372. ISSN 1664-302X Institutional support: RVO:60077344 Keywords : limestone statue * epilithic microbiota * bacteria l cultivation * carbonatogenesis * vaterite Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.076, year: 2016

  8. Short-term effects of medetomidine on photosynthesis and protein synthesis in periphyton, epipsammon and plankton communities in relation to predicted environmental concentrations.

    Science.gov (United States)

    Ohlauson, Cecilia; Eriksson, Karl Martin; Blanck, Hans

    2012-01-01

    Medetomidine is a new antifouling substance, highly effective against barnacles. As part of a thorough ecotoxicological evaluation of medetomidine, its short-term effects on algal and bacterial communities were investigated and environmental concentrations were predicted with the MAMPEC model. Photosynthesis and bacterial protein synthesis for three marine communities, viz. periphyton, epipsammon and plankton were used as effect indicators, and compared with the predicted environmental concentrations (PECs). The plankton community showed a significant decrease in photosynthetic activity of 16% at 2 mg l⁻¹ of medetomidine, which was the only significant effect observed. PECs were estimated for a harbor, shipping lane and marina environment using three different model scenarios (MAMPEC default, Baltic and OECD scenarios). The highest PEC of 57 ng l⁻¹, generated for a marina with the Baltic scenario, was at least 10,000-fold lower than the concentration that significantly decreased photosynthetic activity. It is concluded that medetomidine does not cause any acute toxic effects on bacterial protein synthesis and only small acute effects on photosynthesis at high concentrations in marine microbial communities. It is also concluded that the hazard from medetomidine on these processes is low since the effect levels are much lower than the highest PEC.

  9. Diversity and structure of periphyton and metaphyton diatom communities in a tropical wetland in Mexico Diversidad y estructura de las comunidades de diatomeas del perifiton y el metafiton en un humedal tropical en México

    Directory of Open Access Journals (Sweden)

    Claudia Ibarra

    2009-12-01

    Full Text Available We investigated the structure and diversity of diatoms in communities of metaphyton and periphyton from the wetland of El Edén Ecological Reserve, Quintana Roo, Mexico. In spite of the close association and communication between these communities, our comparisons reveal that the 2 communities have distinct species assemblages, with the periphyton being more diverse overall. We fit abundance curves for periphyton and metaphyton, and argue that our results are consistent with communities where environmental conditions play a more important role than competition in structuring diatom species assemblages.Investigamos la estructura y la diversidad de las comunidades de diatomeas en el metafiton y el perifiton del humedal de la Reserva Ecológica El Edén, Quintana Roo, México. A pesar de la cercana asociación entre estas comunidades, nuestro análisis revela que tanto el perifiton como el metafiton consisten de distintas asociaciones de especies y el perifiton es el más diverso. Las distribuciones de las abundancias de las especies de diatomeas satisfacen curvas de distribución log-normal; esto significa que en las comunidades estudiadas, las condiciones ambientales juegan un papel más importante que la competencia para determinar su estructura.

  10. New evidences of Roundup (glyphosate formulation) impact on the periphyton community and the water quality of freshwater ecosystems.

    Science.gov (United States)

    Vera, María S; Lagomarsino, Leonardo; Sylvester, Matías; Pérez, Gonzalo L; Rodríguez, Patricia; Mugni, Hernán; Sinistro, Rodrigo; Ferraro, Marcela; Bonetto, Carlos; Zagarese, Horacio; Pizarro, Haydée

    2010-04-01

    Argentina is the second largest world producer of soybeans (after the USA) and along with the increase in planted surface and production in the country, glyphosate consumption has grown in the same way. We investigated the effects of Roundup (glyphosate formulation) on the periphyton colonization. The experiment was carried out over 42 days in ten outdoor mesocosms of different typology: "clear" waters with aquatic macrophytes and/or metaphyton and "turbid" waters with great occurrence of phytoplankton or suspended inorganic matter. The herbicide was added at 8 mg L(-1) of the active ingredient (glyphosate) in five mesocosms while five were left as controls (without Roundup addition). The estimate of the dissipation rate (k) of glyphosate showed a half-life value of 4.2 days. Total phosphorus significantly increased in treated mesocosms due to Roundup degradation what favored eutrophication process. Roundup produced a clear delay in periphytic colonization in treated mesocosms and values of the periphytic mass variables (dry weight, ash-free dry weight and chlorophyll a) were always higher in control mesocosms. Despite the mortality of algae, mainly diatoms, cyanobacteria was favored in treated mesocosms. It was observed that glyphosate produced a long term shift in the typology of mesocosms, "clear" turning to "turbid", which is consistent with the regional trend in shallow lakes in the Pampa plain of Argentina. Based on our findings it is clear that agricultural practices that involve the use of herbicides such as Roundup affect non-target organisms and the water quality, modifying the structure and functionality of freshwater ecosystems.

  11. Review on Periphyton as Mediator of Nutrient Transfer in Aquatic Ecosystems

    Directory of Open Access Journals (Sweden)

    Surjya K. Saikia

    2011-12-01

    Full Text Available In the studies of aquatic ecology, periphyton has been uncared for despite its vital role in nutrient uptake and transfer to the upper trophic organisms. Being the component of food chain as attached organism it takes part in nutrient cycling in the ecosystem like that of suspended planktonic counterparts. The present review, with an aim to understand the role of periphyton in nutrient transfer from benthic environment to upper trophic level, focuses many aspects of periphyton-nutrient relationship based on available literatures. It also attempts to redefine periphyton, as a part of biofilm, harboring nutrient components like protein, fat and carbohydrate preferably in its extracellular polymeric substance (EPS, cyanobacteria, diatom and other algal communities. In addition to physical processes, nutrient uptake by periphyton is catalyzed by enzymes like Nitrogen Reductase and Alkaline Phosphatase from the environment. This uptake and transfer is further regulated by periphytic C: nutrient (N or P stoichiometry, colonization time, distribution of periphyton cover on sediments and macrophytes, macronutrient concentration, grazing, sloughing, temperature, and advective transport. The Carbon (C sources of periphyton are mainly dissolve organic matter and photosynthetic C that enters into higher trophic levels through predation and transfers as C-rich nutrient components. Despite of emerging interests on utilizing periphyton as nutrient transfer tool in aquatic ecosystem, the major challenges ahead for modern aquatic biologists lies on determining nutrient uptake and transfer rate of periphyton, periphytic growth and simulating nutrient models of periphyton to figure a complete energy cycle in aquatic ecosystem.

  12. State of the art on periphyton knowledge in Colombia

    International Nuclear Information System (INIS)

    Montoya Moreno, Yimmy; Aguirre R, Nestor

    2013-01-01

    Periphyton is a component of aquatic communities, composed by microbiota adhered to different substrates; plays a fundamental role in matter, energy and information transferences trough food webs and its study is important both from ecology, to understand ecosystems, as from environmental points of view, as periphyton is a good indicator of environmental processes and conditions, for instance water quality, in those ecosystems. Periphyton research is complex; even periphyton definition is still controversial. In addition to that, the variety of methodologies for comprehensive study, the diversity of peri phytic matrix architectures, the diversity of ecosystems and the absence of taxonomic schools in the country, are causing that few works are being published on the subject, which increases the value and importance of the work outlined in this review. The aim of this paper is to present the state of the art in research on periphyton in Colombia, analyzing different lines of research that has been developed and their progress. In order to do this, we examined 84 papers available to the authors. Most studies surveyed in this study (90%) correspond to the study of phycoperiphyton; the remaining 10% included both components of periphyton; one paper was dedicated exclusively to zooperiphyton. Only 10.5% of investigations (8 papers) have been dedicated to detailed taxonomic study; other publications study the structure and dynamics of the periphytic community.

  13. Succession and seasonal variation in epilithic biofilms on artificial reefs in culture waters of the sea cucumber Apostichopus japonicus

    Science.gov (United States)

    Liu, Liming; Du, Rongbin; Zhang, Xiaoling; Dong, Shuanglin; Sun, Shichun

    2017-01-01

    Periphytic biofilms in aquaculture waters are thought to improve water quality, provide an additional food source, and improve the survival and growth of some reared animals. In the Asia- Pacific region, particularly in China, artificial reefs are commonly used in the commercial farming of sea cucumbers. However, few studies have examined the epilithic biofilms on the artificial reefs. To gain a better understanding of the succession of epilithic biofilms and their ecological processes in sea cucumber culture waters, two experiments were conducted in culture waters of the sea cucumber Apostichopus japonicus in Rongcheng, China, using artificial test panels. On the test panels of succession experiment, more than 67 species were identified in the biofilms. On the test panels of seasonal variation experiment, more than 46 species were recorded in the biofilms. In both experiments, communities of epilithic biofilms were dominated by diatoms, green algae and the annelid Spirorbis sp. In the initial colonization, the dominant diatoms were Cocconeis sp., Amphora spp. and Nitzschia closterium in June, which were succeeded by species of Navicula, Cocconeis and Nitzschia (July to September), and then by Licmophora abbreviata, Nitzschia closterium and Synedra spp. in the following months. A diatom bloom in the autumn and filamentous green algae burst in the summer were also observed. Ecological indices well annotated the succession and seasonal changes in epilithic communities. Multidimensional scaling (MDS) analysis found significant differences in diatom community composition among months and seasons. Fast growth of biofilms was observed in the summer and autumn, whereas the biomass of summer biofilms was largely made up of filamentous green algae. Present results show that the components of epilithic biofilms are mostly optimal foods of A. japonicus, suggesting that biofilms on artificial reefs may contribute important nutritional sources for sea cucumbers during their

  14. Distribution of Epilithic Diatoms in Estuaries of the Korean Peninsula in Relation to Environmental Variables

    Directory of Open Access Journals (Sweden)

    Ha-Kyung Kim

    2015-11-01

    Full Text Available This study explores the relationships between environmental factors and the distribution of epilithic diatoms in 161 estuaries of three coastal areas on the Korean peninsula. We investigated epilithic diatoms, water quality, and land use in the vicinities of the estuaries during the months of May 2012, 2013 and 2014, because Korea is relatively free from the influences of rainfall at that time of year. We recorded 327 diatom taxa from the study sites, and the assemblage was dominated by members of the Naviculaceae. Bacillariaceae accounted for the largest proportion of diatoms, and Nitzschia inconspicua (18% and N. frustulum (9.6% were the most dominant species. A cluster analysis based on epilithic diatom abundance suggested that the epilithic diatom communities of Korean estuaries can be classified into four large groups (G according to geography, as follows: Ia—the East Sea watershed, Ib—the eastern watershed of the South Sea, IIa—the West Sea watershed, and IIb—the western watershed of the South Sea. The former two groups, Ia and Ib, showed higher proportions of forest land cover and use, higher species occurrence, lower salinity, lower turbidity, and lower concentrations of nutrients than the latter two groups, while the latter groups, IIa and IIb, had higher proportions of agricultural land cover and use, higher electrical conductivity, higher turbidity, higher concentrations of nutrients, and lower species occurrence. The environmental factors underlying the distribution of epilithic diatoms, representative of each region, are as follows: dissolved oxygen and forest land cover and use for Reimeria sinuate and Rhoicosphenia abbreviate of the East Sea (ES, salinity and turbidity for Tabularia fasciculate of the West Sea (WS, and biochemical oxygen demand (BOD and nutrients for Cyclotella meneghiniana of the WS. On the other hand, the most influential environmental factors affecting the occurrence of indicator species showing the

  15. Periphyton changes over 20 years of chemical recovery of Lake Orta, Italy: differential response to perturbation of littoral and pelagic communities

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    Giuseppe MORABITO

    2011-08-01

    Full Text Available Lake Orta, a large Italian subalpine lake, has a long history of industrial pollution by acid, ammonia, and metals. A whole-lake liming treatment in 1989-1990 led to a gradual increase in pH (from 4.4 to 7 and a concomitant decline in ammonia (from 2.5 to 0.05 mg L-1 and metal concentrations (e.g., copper: from 35 to 3 μg L-1. In this study, we examine the response of the littoral zone, in terms of chemistry and periphyton assemblages, to contamination and recovery of Lake Orta. We compare these findings with a long-term data set of chemistry and phytoplankton collected in the pelagic zone. We sampled periphyton at two sites from the liming period (1989 through 2010 when the lake approached chemical equilibrium. Chemical variables collected in the littoral zone near the periphyton samples followed the same temporal trends observed in the pelagic zone. Chlorophytes, the dominant algae in the preliming period, progressively waned after the calcium carbonate addition. Diatom importance gradually increased to reach up to 80% of the total biovolume in the most recent years. There was a clear shift in the diatom taxonomic composition over the study period. Acidophilous Pinnularia subcapitata var. hilseana and metal-tolerant Achnanthes minutissima were dominant before liming. With the progressive increase in pH and decline in metal concentrations, there was successively the dominance of Fragilaria nanoides (formerly identified as Synedra tenera and Cymbella microcephala in the transition period and of circumneutral Navicula cryptocephala, N. radiosa, and Synedra ulna in the most recent period. Pelagic diatoms were more affected than benthic diatoms by the industrial pollution and their recovery after the liming intervention was slower. Whereas present periphyton diatom assemblages are similar to those observed in nearby unpolluted Lake Mergozzo, pelagic assemblages are still in transition from severe disturbance towards characteristics reported before

  16. Periphyton changes over 20 years of chemical recovery of Lake Orta, Italy: differential response to perturbation of littoral and pelagic communities

    OpenAIRE

    Giuseppe MORABITO; Gabriele TARTARI; Rosario MOSELLO; Michèle DE SÈVE; Antonella CATTANEO

    2011-01-01

    Lake Orta, a large Italian subalpine lake, has a long history of industrial pollution by acid, ammonia, and metals. A whole-lake liming treatment in 1989-1990 led to a gradual increase in pH (from 4.4 to 7) and a concomitant decline in ammonia (from 2.5 to 0.05 mg L-1) and metal concentrations (e.g., copper: from 35 to 3 μg L-1). In this study, we examine the response of the littoral zone, in terms of chemistry and periphyton assemblages, to contamination and recovery of Lake Orta. We co...

  17. Stream periphyton responses to mesocosm treatments of ...

    Science.gov (United States)

    A stream mesocosm experiment was designed to compare biotic responses among streams exposed to an equal excess specific conductivity target of 850 µS/cm relative to a control that was set for 200 µS/cm and three treatments comprised of different major ion contents. Each treatment and the control was replicated 4 times at the mesocosm scale (16 mesocosms total). The treatments were based on dosing the background mesocosm water, a continuous flow-through mixture of natural river water and reverse osmosis treated water, with stock salt solutions prepared from 1) a mixture of sodium chloride and calcium chloride (Na/Cl chloride), 2) sodium bicarbonate, and 3) magnesium sulfate. The realized average specific conductance over the first 28d of continuous dosing was 827, 829, and 847 µS/cm, for the chloride, bicarbonate, and sulfate based treatments, respectively, and did not differ significantly. The controls averaged 183 µS/cm. Here we focus on comparing stream periphyton communities across treatments based on measurements obtained from a Pulse-Amplitude Modulated (PAM) fluorometer. The fluorometer is used in situ and with built in algorithms distributes the total aerial algal biomass (µg/cm2) of the periphyton among cyanobacteria, diatoms, and green algae. A measurement is recorded in a matter of seconds and, therefore, many different locations can be measured with in each mesocosm at a high return frequency. Eight locations within each of the 1 m2 (0.3 m W x 3

  18. The potential of fish production based on periphyton

    NARCIS (Netherlands)

    Dam, van A.A.; Beveridge, M.C.M.; Azim, M.E.; Verdegem, M.C.J.

    2002-01-01

    Periphyton is composed of attached plant and animal organisms embedded in a mucopolysaccharide matrix. This review summarizes research on periphyton-based fish production and on periphyton productivity and ingestion by fish, and explores the potential of developing periphyton-based aquaculture.

  19. Succession of Periphyton and Phytoplankton Assemblages in Years with Varying Amounts of Precipitation in a Shallow Urban Lake (Lake Jeziorak Mały, Poland

    Directory of Open Access Journals (Sweden)

    Zębek Elžbieta

    2014-08-01

    Full Text Available This study of periphyton assemblages (periphyton in separator pipes, epilithon and epiphyton and phytoplankton was carried out in Lake Jeziorak Maly in 1997-2003 and 2005. Since precipitation amounts varied in these years, changes in the abundance, biomass, taxonomic group structure, spe-cies diversity and dominant taxa of these assemblages were analyzed in relation to the physical and chemical water parameters. The periphyton in pipes had their highest abundance and biomass at the mean precipitation in the vegetative season and at maximum precipitations in winter 2000, and also in the 1997 vegetative season when there were high levels of electrolytic conductivity and orthophosphate and chloride concentrations. The assemblage was dominated by the diatoms Diatoma vulgaris which was resistant to washing and Navicula gregaria resistant to high amounts of organic matter. Similarly, maximum abundance and biomass of epilithon was found at the maximum precipitation level. However, in 2003 there was a low precipitation level which favoured habitation by epilithic filamentous chlorophytes, especially Ulothrix tenuissima. Meanwhile, epiphyton and phytoplankton thrived best in the high precipitation conditions and moderate chloride concentration in 2001. These assemblages were dominated by species typical for eutrophic waters, such as Gomphonema oliva-ceum and Planktolyngbya brevicellularis. Differences in the dynamics of periphyton assemblages and phytoplankton in the studied years indicate varying succession rates in these assemblages, especially in the separator pipes and on stones. These phenomena are considered to be related to the different environmental conditions engendered by variable amounts of precipitation.

  20. Short-term uptake of heavy metals by periphyton algae

    Energy Technology Data Exchange (ETDEWEB)

    Vymazal, J.

    1984-12-31

    The utilization of periphyton for the removal of heavy metals from enriched small streams has been examined. By means of short-term batch laboratory experiments the courses of metal uptake have been studied. For uptake study naturally growing periphyton community and periphytic filamentous algae Cladophora glomerata and Oedogonium rivulare have been used. Uptakes of nine heavy metals (Pb, Cd, Cu, Co, Cr, Ni, Zn, Fe and Mn) have been determined during four hours exposure. In addition the influence of humic substances on heavy metals uptake has been determined. Uptake of all metals increased during four hours exposure but not in the same way. Some metals were removed continuously (Ni, Cr, Fe and Mn), other metals were removed more rapidly during the first hour or first two hours of exposure and then only slight removal continued (Cu, Pb, Cd, Co). Uptake of Zn was rather unambiguous. Results of these experiments suggest that the course of uptake for individual metals could be similar for most periphyton algae. It was established that humic substances significantly reduce heavy metals uptake. The highest decrease of uptake was observed in Cu, Cr, Co and Cd. The results of model experiments are being tested in a pilot scale with respect to the demands of engineering practice. (J.R.)

  1. Periphyton indicate effects of wastewater discharge in the near-coastal zone, Perth (Western Australia)

    Science.gov (United States)

    Cosgrove, Jeffrey; Walker, Di; Morrison, Peter; Hillman, Karen

    2004-10-01

    Periphyton communities on artificial substrata were successfully utilised as a biological indicator of the potential eutrophic effects of wastewater discharge into coastal waters off Perth, Western Australia. Biomass and percentage carbonate content measurements of periphyton communities grown in situ indicated that the periphyton primary production (organic weight) was enhanced in the vicinity of the discharge outlets, with a significant negative correlation between distance north of the northern outlet in Whitfords Lagoon and periphyton organic weight (OW) observed in autumn at a depth of 4 m ( r = -0.704, P relatively calm autumn season and substrata at depths of 2 m and 4 m. Thus, in favourable conditions phytoplankton and high relief reef communities are more likely to exhibit a eutrophic influence (in the form of enhanced primary production) of the treated wastewater discharge. Laboratory studies confirmed that treated wastewater, diluted 100-fold to estimate surface concentrations above the wastewater outfalls in the field, stimulates periphyton growth above levels recorded in unpolluted seawater ( F = 12.485; P = 0.0073).

  2. Hydrophysical conditions and periphyton in natural rivers. Analysis and predictive modelling of periphyton by changed regulations

    International Nuclear Information System (INIS)

    Stokseth, S.

    1994-10-01

    The objective of this thesis has been to examine the interaction between hydrodynamical and physical factors and the temporal and spatial dynamics of periphyton in natural steep rivers. The study strategy has been to work with quantitative system variables to be able to evaluate the potential usability of a predictive model for periphyton changes as a response to river regulations. The thesis is constituted by a theoretical and an empirical study. The theoretical study is aimed at presenting a conceptual model of the relevant factors based on an analysis of published studies. Effort has been made to evaluate and present the background material in a structured way. To concurrently handle the spatial and temporal dynamics of periphyton a new method for data collection has been developed. A procedure for quantifying the photo registrations has been developed. The simple hydrodynamical parameters were estimated from a set of standard formulas whereas the complex parameters were estimated from a three dimensional simulation model called SSIIM. The main conclusion from the analysis is that flood events are the major controlling factors wrt. periphyton biomass and that water temperature is of major importance for the periphyton resistance. Low temperature clearly increases the periphyton erosion resistance. Thus, to model or control the temporal dynamics the river periphyton, the water temperature and the frequency and size of floods should be regarded the most significant controlling factors. The data in this study has been collected from a river with a stable water quality and frequent floods. 109 refs., 41 figs., 34 tabs

  3. Temperature modulates phototrophic periphyton response to chronic copper exposure

    International Nuclear Information System (INIS)

    Lambert, Anne Sophie; Dabrin, Aymeric; Morin, Soizic; Gahou, Josiane; Foulquier, Arnaud; Coquery, Marina; Pesce, Stéphane

    2016-01-01

    Streams located in vineyard areas are highly prone to metal pollution. In a context of global change, aquatic systems are generally subjected to multi-stress conditions due to multiple chemical and/or physical pressures. Among various environmental factors that modulate the ecological effects of toxicants, special attention should be paid to climate change, which is driving an increase in extreme climate events such as sharp temperature rises. In lotic ecosystems, periphyton ensures key ecological functions such as primary production and nutrient cycling. However, although the effects of metals on microbial communities are relatively well known, there is scant data on possible interactions between temperature increase and metal pollution. Here we led a study to evaluate the influence of temperature on the response of phototrophic periphyton to copper (Cu) exposure. Winter communities, collected in a 8 °C river water, were subjected for six weeks to four thermal conditions in microcosms in presence or not of Cu (nominal concentration of 15 μg L"−"1). At the initial river temperature (8 °C), our results confirmed the chronic impact of Cu on periphyton, both in terms of structure (biomass, distribution of algal groups, diatomic composition) and function (photosynthetic efficiency). At higher temperatures (13, 18 and 23 °C), Cu effects were modulated. Indeed, temperature increase reduced Cu effects on algal biomass, algal class proportions, diatom assemblage composition and photosynthetic efficiency. This reduction of Cu effects on periphyton may be related to lower bioaccumulation of Cu and/or to selection of more Cu-tolerant species at higher temperatures. - Highlights: • At in situ temperature, Cu impacted structure and activity of phototrophic biofilms. • Cu effects were reduced with increasing temperature (from +5 °C to +15 °C). • The decrease in Cu effects may be related to lower Cu bioaccumulation in biofilms. • Changes in diatom

  4. The response of stream periphyton to Pacific salmon: using a model to understand the role of environmental context

    Science.gov (United States)

    Bellmore, J. Ryan; Fremier, Alexander K.; Mejia, Francine; Newsom, Michael

    2014-01-01

    1. In stream ecosystems, Pacific salmon deliver subsidies of marine-derived nutrients and disturb the stream bed during spawning. The net effect of this nutrient subsidy and physical disturbance on biological communities can be hard to predict and is likely to be mediated by environmental conditions. For periphyton, empirical studies have revealed that the magnitude and direction of the response to salmon varies from one location to the next. Salmon appear to increase periphyton biomass and/or production in some contexts (a positive response), but decrease them in others (a negative response). 2. To reconcile these seemingly conflicting results, we constructed a system dynamics model that links periphyton biomass and production to salmon spawning. We used this model to explore how environmental conditions influence the periphyton response to salmon. 3. Our simulations suggest that the periphyton response to salmon is strongly mediated by both background nutrient concentrations and the proportion of the stream bed suitable for spawning. Positive periphyton responses occurred when both background nutrient concentrations were low (nutrient limiting conditions) and when little of the stream bed was suitable for spawning (because the substratum is too coarse). In contrast, negative responses occurred when nutrient concentrations were higher or a larger proportion of the bed was suitable for spawning. 4. Although periphyton biomass generally remained above or below background conditions for several months following spawning, periphyton production returned quickly to background values shortly afterwards. As a result, based upon our simulations, salmon did not greatly increase or decrease overall annual periphyton production. This suggests that any increase in production by fish or invertebrates in response to returning salmon is more likely to occur via direct consumption of salmon carcasses and/or eggs, rather than the indirect effects of greater periphyton production. 5

  5. Response of periphyton fatty acid composition to supplemental flows in the upper Esopus Creek, Catskill Mountains, New York

    Science.gov (United States)

    George, Scott D.; Ernst, Anne G.; Baldigo, Barry P.; Honeyfield, Dale C.

    2016-01-07

    Fatty acid analysis of periphyton is an emerging tool for assessing the condition of a stream ecosystem on the basis of its water quality. The study presented in this report was designed to test the hypothesis that periphyton communities have a fatty acid profile that can detect excessive turbidity and suspended sediment. The fatty acid composition of periphyton was assessed during two seasons upstream and downstream from an underground aqueduct that provides supplemental flows, which are a potential source of turbidity and suspended sediment on the upper Esopus Creek, New York. These data were compared with measurements of periphyton standing crop, diatom community structure and integrity, and basic water-quality parameters. Periphyton standing crop and diatom community integrity indicated little evidence of impairment from the supplemental flows. The relative abundances of two physiologically important fatty acids, γ-linolenic acid (18:3ω6) and eicosapentaenoic acid (20:5ω3), were significantly lower downstream from the supplemental flows and multivariate analyses of fatty acid profiles identified significant differences between sites upstream and downstream from the supplemental flows. Individual fatty acids and summary metrics, however, were not significantly correlated with turbidity or suspended sediment. Together, these results indicate that the supplemental flows may cause some measurable effects but they do not constitute a major disturbance to the periphyton community on the upper Esopus Creek. Fatty acid analysis may have potential as a tool for monitoring changes in periphyton nutritional composition that may reflect water quality and ecosystem health but needs to be further evaluated around a more definitive source of water-quality impairment.

  6. Cryptofauna of the epilithic algal matrix on an inshore coral reef, Great Barrier Reef

    Science.gov (United States)

    Kramer, M. J.; Bellwood, D. R.; Bellwood, O.

    2012-12-01

    Composed of a collection of algae, detritus, sediment and invertebrates, the epilithic algal matrix (EAM) is an abundant and ubiquitous feature of coral reefs. Despite its prevalence, there is a paucity of information regarding its associated invertebrate fauna. The cryptofaunal invertebrate community of the EAM was quantitatively investigated in Pioneer Bay on Orpheus Island, Great Barrier Reef. Using a vacuum collection method, a diversity of organisms representing 10 different phyla were identified. Crustacea dominated the samples, with harpacticoid copepods being particularly abundant (2025 ± 132 100 cm-2; mean density ± SE). The volume of coarse particulate matter in the EAM was strongly correlated with the abundance of harpacticoid copepods. The estimated biomass of harpacticoid copepods (0.48 ± 0.05 g m-2; wet weight) suggests that this group is likely to be important for reef trophodynamics and nutrient cycling.

  7. Rapid sewage pollution assessment by means of the coverage of epilithic taxa in a coastal area in the SW Atlantic.

    Science.gov (United States)

    Becherucci, M E; Jaubet, M L; Saracho Bottero, M A; Llanos, E N; Elías, R; Garaffo, G V

    2018-07-01

    The sewage pollution impact over coastal environment represents one of the main reasons explaining the deterioration of marine coastal ecosystems around the globe. This paper aims to detect promptly a putative sewage pollution impact in a Southwestern Atlantic coastal area of Argentina as well as to identify a straightforward way for monitoring, based on the relative abundance coverage of the intertidal epilithic taxa. Four sampling sites were distributed at increased distances from the sewage outfall where the cover of individual epilithic species was visually estimated. The surrounded outfall area (i.e. outfall site) resulted polluted with high percentages of organic matter in sediment and Enterococcus concentration in seawater. The structure of the community showed a remarkable difference between the polluted site (outfall site) and the unpolluted sites. The polychaete Boccardia proboscidea dominated the outfall site with variable abundances of the green algae Ulva sp. during the period of study, decreasing the diversity of the community, while the mussel Brachidontes rodriguezii and variable abundances of several algae species dominated the unpolluted sites. The monitoring of the benthic community represents an effective, non-destructive, relative inexpensive and rapid method to assess the health of the coastal environment in the study area. The large abundance of B. proboscidea along with the absence of B. rodriguezii individuals at coastal ecosystem with certain gradient of pollution. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Trophic partitioning among three littoral microcrustaceans: relative importance of periphyton as food resource

    Directory of Open Access Journals (Sweden)

    Alexandre Bec

    2012-07-01

    Full Text Available The high species richness of zooplankton communities in macrophytes littoral zones could result from the diversity of potential trophic niches found in such environment. In macrophytes littoral zones, in addition to phytoplankton, neustonic, benthic and epiphytic biofilms can also be potential components of the microcrustacean diet. Here, we investigated the ability of three large cladocerans: Daphnia longispina, Simocephalus vetulus and Eurycercus lamellatus, to develop on periphyton as their only food source or as a complement to a phytoplankton resource in scarce supply. D. longispina exhibited a very low growth and reproduction rates on the periphytic resource and as S. vetulus seems unable to scrape on periphyton. In contrast, E. lamellatus could not grow on phytoplankton, and appears to be an obligatory periphyton scraper. This latter finding contrasts with previous studies suggesting that E. lamellatus could be able to scrap periphyton as well as filter-feed on suspended matter. These differences in feeding strategy probably reflect the different trophic niches occupied by these three species in macrophytes littoral zones, and may explain at least in part their ability to coexist in the same environment.

  9. Factors Controlling Changes in Epilithic Algal Biomass in the Mountain Streams of Subtropical Taiwan.

    Directory of Open Access Journals (Sweden)

    Yi-Ming Kuo

    Full Text Available In upstream reaches, epilithic algae are one of the major primary producers and their biomass may alter the energy flow of food webs in stream ecosystems. However, the overgrowth of epilithic algae may deteriorate water quality. In this study, the effects of environmental variables on epilithic algal biomass were examined at 5 monitoring sites in mountain streams of the Wuling basin of subtropical Taiwan over a 5-year period (2006-2011 by using a generalized additive model (GAM. Epilithic algal biomass and some variables observed at pristine sites obviously differed from those at the channelized stream with intensive agricultural activity. The results of the optimal GAM showed that water temperature, turbidity, current velocity, dissolved oxygen (DO, pH, and ammonium-N (NH4-N were the main factors explaining seasonal variations of epilithic algal biomass in the streams. The change points of smoothing curves for velocity, DO, NH4-N, pH, turbidity, and water temperature were approximately 0.40 m s-1, 8.0 mg L-1, 0.01 mg L-1, 8.5, 0.60 NTU, and 15°C, respectively. When aforementioned variables were greater than relevant change points, epilithic algal biomass was increased with pH and water temperature, and decreased with water velocity, DO, turbidity, and NH4-N. These change points may serve as a framework for managing the growth of epilithic algae. Understanding the relationship between environmental variables and epilithic algal biomass can provide a useful approach for maintaining the functioning in stream ecosystems.

  10. Effect of glyphosate acid on biochemical markers of periphyton exposed in outdoor mesocosms in the presence and absence of the mussel Limnoperna fortunei.

    Science.gov (United States)

    Iummato, María Mercedes; Pizarro, Haydée; Cataldo, Daniel; Di Fiori, Eugenia; Dos Santos Afonso, María; Del Carmen Ríos de Molina, María; Juárez, Ángela Beatriz

    2017-07-01

    Glyphosate is currently the most widely used herbicide in agricultural production. It generally enters aquatic ecosystems through surface water runoff and aerial drift. We evaluated the effect of glyphosate acid on biochemical parameters of periphyton exposed to concentrations of 1, 3, and 6 mg/L in outdoor mesocosms in the presence and absence of the mussel Limnoperna fortunei. Periphyton ash-free dry weight, chlorophyll a content, carotene/chlorophyll a ratio, lipid peroxidation levels, and superoxide dismutase and catalase activities were determined at days 0, 1, 7, 14, and 26 of the experimental period. Ash-free dry weight was similar between control and glyphosate-treated periphyton in the absence of L. fortunei. The latter had significantly lower carotene to chlorophyll a ratios and enzyme activities, and higher lipid peroxidation levels and chlorophyll a content than the former. These results show an adverse effect of glyphosate on the metabolism of periphyton community organisms, possibly inducing oxidative stress. On the contrary, no differences were observed in any of these variables between control and glyphosate-treated periphyton in the presence of L. fortunei. Mussels probably attenuated the herbicide effects by contributing to glyphosate dissipation. The results also demonstrate that biochemical markers provide useful information that may warn of herbicide impact on periphyton communities. Environ Toxicol Chem 2017;36:1775-1784. © 2016 SETAC. © 2017 SETAC.

  11. Physical, Chemical and Periphyton/Phytoplankton Study of Onah ...

    African Journals Online (AJOL)

    physico-chemical parameter, viz: ionic conductivity factor contributed 26.07%, nutrient factor contributed 40.61% while dissolved oxygen factor contributed 33.32%. Three divisions, eight families and ten species of periphyton were encountered. The most abundant periphyton species recorded are Closterium spp. (26.37%) ...

  12. Soil and periphyton indicators of anthropogenic water-quality changes in a rainfall-driven wetland

    Science.gov (United States)

    McCormick, P.V.

    2011-01-01

    Surface soils and periphyton communities were sampled across an oligotrophic, soft-water wetland to document changes associated with pulsed inputs of nutrient- and mineral-rich canal drainage waters. A gradient of canal-water influence was indicated by the surface-water specific conductance, which ranged between 743 and 963 ??S cm-1 in the canals to as low as 60 ??S cm-1 in the rainfall-driven wetland interior. Changes in soil chemistry and periphyton taxonomic composition across this gradient were described using piecewise regressions models. The greatest increase in soil phosphorus (P) concentration occurred at sites closest to the canal while soil mineral (sulfur, calcium) concentrations increased most rapidly at the lower end of the gradient. Multiple periphyton shifts occurred at the lower end of the gradient and included; (1) a decline in desmids and non-desmid filamentous chlorophytes, and their replacement by a diatom-dominated community; (2) the loss of soft-water diatom indicator species and their replacement by hard-water species. Increased dominance by cyanobacteria and eutrophic diatom indicators occurred closer to the canals. Soil and periphyton changes indicated four zones of increasing canal influence across the wetland: (1) a zone of increasing mineral concentrations where soft-water taxa remained dominant; (2) a transition towards hard-water, oligotrophic diatoms as mineral concentrations increased further; (3) a zone of dominance by these hard-water species; (4) a zone of rapidly increasing P concentrations and dominance by eutrophic taxa. In contrast to conclusions drawn from routine water-chemistry monitoring, measures of chemical and biological change presented here indicate that most of this rainfall-driven peatland receives some influence from canal discharges. These changes are multifaceted and induced by shifts in multiple chemical constituents. ?? 2010 US Government.

  13. Short-Term Effects of Drying-Rewetting and Long-Term Effects of Nutrient Loading on Periphyton N:P Stoichiometry

    Directory of Open Access Journals (Sweden)

    Andres D. Sola

    2018-01-01

    Full Text Available Nitrogen (N and phosphorus (P concentrations and N:P ratios critically influence periphyton productivity and nutrient cycling in aquatic ecosystems. In coastal wetlands, variations in hydrology and water source (fresh or marine influence nutrient availability, but short-term effects of drying and rewetting and long-term effects of nutrient exposure on periphyton nutrient retention are uncertain. An outdoor microcosm experiment simulated short-term exposure to variation in drying-rewetting frequency on periphyton mat nutrient retention. A 13-year dataset from freshwater marshes of the Florida Everglades was examined for the effect of long-term proximity to different N and P sources on mat-forming periphyton nutrient standing stocks and stoichiometry. Field sites were selected from one drainage with shorter hydroperiod and higher connectivity to freshwater anthropogenic nutrient supplies (Taylor Slough/Panhandle, TS/Ph and another drainage with longer hydroperiod and higher connectivity to marine nutrient supplies (Shark River Slough, SRS. Total P, but not total N, increased in periphyton mats exposed to both low and high drying-rewetting frequency with respect to the control mats in our experimental microcosm. In SRS, N:P ratios slightly decreased downstream due to marine nutrient supplies, while TS/Ph increased. Mats exposed to short-term drying-rewetting had higher nutrient retention, similar to nutrient standing stocks from long-term field data. Periphyton mat microbial communities may undergo community shifts upon drying-rewetting and chronic exposure to nutrient loads. Additional work on microbial species composition may further explain how periphyton communities interact with drying-rewetting dynamics to influence nutrient cycling and retention in wetlands.

  14. Composition, Occurrences and Checklist of Periphyton Algae of ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    The periphyton is also an important indicator of water quality (Azim et al, 2006). Attached algae are primitive plants that get their nutrients from water passing over them. ... rung in the aquatic food chain depend directly ... influence of sea water.

  15. The Effect of Zebra Mussels on Algal Community Structure in an Impounded River System

    Science.gov (United States)

    Trumble, A. F.; Luttenton, M.

    2005-05-01

    The zebra mussel, Dreissena polymorpha, invaded the Great Lakes Region in the mid 1980's, and subsequently colonized inland lakes and coastal river systems through secondary invasions. The Muskegon River below Croton Dam was colonized by zebra mussels in 2000 following their introduction into Croton impoundment in the late 1990's. No zebra mussels were found below Croton Dam in 1999 but had increased to 25,000 m-2 by 2001. We examined the affect of zebra mussels on epilithic periphyton communities by comparing plots that were and were not colonized by zebra mussels. Chlorophyll a increased in both treatments over time but was significantly higher in control plots than in zebra mussel plots. The concentration of chlorophyll a in the control plots increased from 14 µgcm-2 to 26 µgcm-2 and the concentration in the zebra mussel plots started at 12 µgcm-2, peaked at 19 µgcm-2, and then decreased to 15 µgcm-2 over a 6 week period. In a related experiment using artificial streams, chlorophyll a increased with increasing zebra mussel density, but differences were not significant. The different trends observed between the two experiments may be explained in part by arthropod invertebrates associated with zebra mussel populations.

  16. Ecological responses of epilithic diatoms and aquatic macrophytes to fish farm pollution in a Spanish river

    Directory of Open Access Journals (Sweden)

    Camargo, Julio A.

    2007-12-01

    Full Text Available We examined the ecological responses of epilithic diatoms and aquatic macrophytes to organic pollution and nutrient enrichment caused by a trout farm effluent in the upper Tajuña River (Guadalajara, Spain. Four sampling sites were selected over the study area: one site (S-1 placed upstream from the trout farm was used as a reference station; sampling sites S-2, S-3 and S-4 were set, respectively, about 10, 100 and 1000 metres downriver of the trout farm outlet. The river bottom was mainly stony with cobbles and pebbles at S-1, S-3 and S-4, but at S-2 it was covered by a thick layer of organic sediment. Although some macrophyte species (Apium nodiflorum, Groenlandia densa were either absent or fewer downstream of the farm, abundance (% coverage and diversity (number of species for the aquatic macrophyte community as a whole increased. In contrast, epilithic diatoms were completely absent at S-2, and some species (Diploneis parma, Fragilaria ulna, Gomphonema angustatum, Nitzschia dissipata were also absent at S-3 and S-4. Indeed, diatom diversity (number of species was lower at S-3 and S-4 than at S-1. However, diatom abundance (cells/cm2 was higher at S-3 and S-4 than at S-1. Biological indices for diatoms (IBD, TDI indicated a better water quality at S-1 than at S-3 and S-4, with a clear tendency to improve with distance from the fish farm. In contrast, biological indices of macrophytes (IM, IVAMG indicated a similar water quality at S-1, S-3 and S-4, but with bad water quality at S-2. We conclude that epilithic diatoms may be more useful than aquatic macrophytes for biological monitoring of fish farm pollution in fluvial ecosystems. However, as historical and seasonal factors may be relevant to understanding the distribution, abundance and diversity of primary producers in running waters, further studies on long-term seasonal changes are needed to improve the use of macrophyte and diatom indices in assessing fish farm pollution.En este trabajo

  17. Co-contamination of Cu and Cd in paddy fields: Using periphyton to entrap heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jiali [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China); College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049 (China); Tang, Cilai [Department of Environmental Engineering, College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002 (China); Wang, Fengwu [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China); School of Civil Engineering, East China Jiaotong University, 808 Shuang Gang East Road, Nanchang, Jiangxi 330013 (China); Wu, Yonghong, E-mail: yhwu@issas.ac.cn [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China)

    2016-03-05

    Highlights: • Periphyton was capable of simultaneously entrapping Cu and Cd from paddy fields. • Cu and Cd bioavailability decreased with time after exposure to periphyton. • Periodic adsorption–desorption was the main mechanism used to remove Cd and Cu. • Periphyton was able to adapt to steady accumulation of Cu and Cd. • The inclusion of periphyton will help entrap heavy metals in paddy fields. - Abstract: The ubiquitous native periphyton was used to entrap Cu and Cd from paddy fields. Results showed that Cu- and Cd-hydrate species such as CuOH{sup +}, Cu{sub 2}(OH){sub 2}{sup 2+}, CdOH{sup +}, and Cu{sub 3}(OH){sub 4}{sup 2+} decreased with time in the presence of periphyton. When the initial concentrations of Cu and Cd were 10 mg/L, the heavy metal content in the periphyton fluctuated from 145.20 mg/kg to 342.42 mg/kg for Cu and from 101.75 mg/kg to 236.29 mg/kg for Cd after 2 h exposure. The concentration of Cd in periphytic cells varied from 42.93 mg/kg to 174 mg/kg after 2 h. The dominant periphyton microorganism species shifted from photoautotrophs to heterotrophs during the exposure of periphyton to Cu and Cd co-contamination. Although Cu and Cd could inhibit periphyton photosynthesis and carbon utilization, the periphyton was able to adapt to the test conditions. Cu and Cd accumulation in rice markedly decreased in the presence of periphyton while the number of rice seeds germinating was higher in the periphyton treatments. These results suggest that the inclusion of native periphyton in paddy fields provides a promising buffer to minimize the effects of Cu and Cd pollution on rice growth and food safety.

  18. Mercury methylation and demethylation by periphyton biofilms and their host in a fluvial wetland of the St. Lawrence River (QC, Canada)

    International Nuclear Information System (INIS)

    Hamelin, Stéphanie; Planas, Dolors; Amyot, Marc

    2015-01-01

    Wetlands in large rivers are important sites of production of the neurotoxin methylmercury (MeHg), and the periphyton growing on wetland macrophytes are increasingly recognized as key players in this production and transfer in food webs. Information is lacking about mercury methylation (K m ) and demethylation (K d ) rates in periphytic biofilms from the Northern Hemisphere, as well as about the drivers of net MeHg production, hampering ecosystem modeling of Hg cycling. Mercury methylation and demethylation rates were measured in periphytic biofilms growing on submerged plants in a shallow fluvial lake located in a temperate cold region (St. Lawrence River, Quebec, Canada). Incubations were performed in situ within macrophyte beds using low-level spikes of 199 HgO and Me 200 Hg stable isotopes as tracers. A direct relationship was observed between K m (0.002 to 0.137 d −1 ) and [MeHg] in periphyton. A similar relationship was found between K d (0.096 to 0.334 d −1 ) and [inorganic Hg]. Periphyton of Lake St. Pierre reached high levels of net MeHg production that were two orders of magnitude higher than those found in local sediment. This production varied through the plant growing season and was mainly driven by environmental variables such as depth of growth, available light, dissolved oxygen, temperature, plant community structure, and productivity of the habitat. - Highlights: • Periphyton Hg methylation and demethylation were studied in a large fluvial lake. • Addition of stable Hg isotopes was used to obtain in situ rates for these processes. • Net methylation was higher in periphyton than in local sediments. • Methylation and demethylation rates fluctuated during the summer. • Key drivers of rates were depth, light, temperature, and community structure

  19. Mercury methylation and demethylation by periphyton biofilms and their host in a fluvial wetland of the St. Lawrence River (QC, Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Hamelin, Stéphanie; Planas, Dolors [GRIL, Département de sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8 (Canada); Amyot, Marc [GRIL, Département de sciences biologiques, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Quebec H3C 3J7 (Canada)

    2015-04-15

    Wetlands in large rivers are important sites of production of the neurotoxin methylmercury (MeHg), and the periphyton growing on wetland macrophytes are increasingly recognized as key players in this production and transfer in food webs. Information is lacking about mercury methylation (K{sub m}) and demethylation (K{sub d}) rates in periphytic biofilms from the Northern Hemisphere, as well as about the drivers of net MeHg production, hampering ecosystem modeling of Hg cycling. Mercury methylation and demethylation rates were measured in periphytic biofilms growing on submerged plants in a shallow fluvial lake located in a temperate cold region (St. Lawrence River, Quebec, Canada). Incubations were performed in situ within macrophyte beds using low-level spikes of {sup 199}HgO and Me{sup 200}Hg stable isotopes as tracers. A direct relationship was observed between K{sub m} (0.002 to 0.137 d{sup −1}) and [MeHg] in periphyton. A similar relationship was found between K{sub d} (0.096 to 0.334 d{sup −1}) and [inorganic Hg]. Periphyton of Lake St. Pierre reached high levels of net MeHg production that were two orders of magnitude higher than those found in local sediment. This production varied through the plant growing season and was mainly driven by environmental variables such as depth of growth, available light, dissolved oxygen, temperature, plant community structure, and productivity of the habitat. - Highlights: • Periphyton Hg methylation and demethylation were studied in a large fluvial lake. • Addition of stable Hg isotopes was used to obtain in situ rates for these processes. • Net methylation was higher in periphyton than in local sediments. • Methylation and demethylation rates fluctuated during the summer. • Key drivers of rates were depth, light, temperature, and community structure.

  20. Periphyton crops and productivity in a reactor thermal effluent

    International Nuclear Information System (INIS)

    Tilly, L.J.

    1975-01-01

    Samples of periphyton grown for two weeks on microscope slides in surface waters of the reactor cooling reservoir, Par Pond, were examined for differences in species composition, diversity, standing crop, and 14 C uptake relatable to 7 positions in the thermal effluent. For stations which differed in average temperature by less than 5 0 C, weight specific productivity differed by a factor of 7. Periphyton biomass differed more than fivefold between stations 5.5 0 C apart. For most incubation intervals, both weight specific productivity and accumulated crop correlated highly with the average growing temperature, but slopes of regressions from consecutive periods often differed greatly while species composition and temperauture regime changed only slightly. Recent experiments indicate that observed differences may be due to interactions between nutrients and temperatures. (U.S.)

  1. A comparative study of the N metabolism of phytoplankton and periphyton communities in oligotrophic lakes. Part of a coordinated programme on isotopic-tracer-aided research and monitoring on agricultural residue - biological interactions in aquatic ecosystems

    International Nuclear Information System (INIS)

    Goldman, C.R.

    1982-08-01

    Limnological research at Castle Lake, CA, and Lake Tahoe, CA-NEV, USA, during the period 1977-1982 has emphasized the effects of nutrient enrichment and deficiency on primary producers. The low ambient pools of nitrogenous nutrients and their low rates of transformation have necessitated the use of isotope tracer methods ( 14 C, 15 N, 13 N). These techniques have been used in concert with physiological assays, growth bio-assays, and whole-ecosystem nitrogen enrichments. Our most significant results, to date, include: (1) Delineation of 5 algal communities which are spatially distinct yet occur in the same lake and which differ with regard to their principal sources of N; (2) Determination of the relative affinities of the above communities for the various sources of N; (3) Demonstration of the importance of internally regenerated N to phytoplankton productivity; (4) Development of sensitive methodology to utilize the short-lived radioisotope 13 N (t1/2=10 mins) for studies of denitrification and nitrate uptake in aquatic ecosystems; (5) Comparisons of a variety of physiological assays for N-deficiency in aquatic microorganisms, involving short-term and long-term experiments in containers and in an N-enriched lake. The controlled ecosystem manipulations were intended to simulate the effects of watershed disturbance on nitrogen loading in order to more accurately evaluate their potential impacts on inorganic carbon and nitrogen assimilation by natural algal communities. Our research is an experimental approach for contrasting the strategies of planktonic and benthic algae living in the same lake but differing with regard to their principal sources of nitrogen

  2. Seasonal patterns of periphyton nitrogen fixation in calcareous wetlands

    Science.gov (United States)

    Liao, X.; Inglett, P.

    2011-12-01

    Periphyton mats are an ecologically important component of the Everglades ecosystem and plays various vital ecological functions. However, nitrogen fixation of periphyton, has received little attention throughout much of the Everglades system. The objective of this study was to characterize the seasonal pattern of periphyton N2 fixation in the Hole-in-the-Donut (HID) of Florida Everglades, where farmed marl prairie wetlands have been restored through complete soil removal (CSR) to reduce nutrient levels. Two restored areas (i.e., cleared in 2000 and 2003) and a reference (natural and unfarmed) marl prairie wetland sites were selected in the HID. Seven times of sampling were performed across the wet and dry season during the 2010 and 2011. The annual fixed nitrogen was approximately 0.4gN m-2 yr-1 in the restored sites which was higher in the reference site (~0.2gN m-2 yr-1). All the three sites showed similar seasonal patterns of N2 fixation that is higher values were observed in the wet season; but the peak value was one month later in reference sits (i.e., September) comparing to the restored areas (i.e., July). The peak of periphyton AR rates in the 2000- and 2003-restored areas appeared in July (i.e., wet season) within the range of 20-79 nmols g-1dw h-1 and 31-53nmols g-1dw h-1, respectively. In contrast, the peak of reference site was observed in September with the range of 2-5 nmols g-1dw h-1. Stable N isotopic ratios (i.e., δ15N) also varied with time but didn't show consistent seasonal pattern as nitrogen fixation. N2 fixation positively correlated with periphyton total phosphorus (TP) and negatively correlated with total nitrogen and phosphorus molar ratios (TN:TP), indicating that N2 fixation would be a indicator of nutrient limitation. In general, δ15N was negatively correlated with nitrogenase activity but the correlation became weakened in the wet season, especially in the flooded July and September, which would be explained by other environmental

  3. Mixed culture of tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) in periphyton-based ponds

    NARCIS (Netherlands)

    Uddin, S.

    2007-01-01

    In recent years, the concept of periphyton-based aquaculture has been tested and applied in aquaculture. Positive effects of substrate addition for periphyton development included increasing the food supply and providing shelter for culture animals. The aim of this project was to develop a low-cost

  4. Effects of nutrients and fish on periphyton and plant biomass across a European latitudinal gradient

    NARCIS (Netherlands)

    Bécares, E.; Gomá, J.; Fernández-Aláez, M.; Fernández-Aláez, C.; Romo, S.; Rosa Miracle, M.; Ståhl-Delbanco, A.; Hansson, L-A.; Gyllström, M.; van de Bund, W.; Van Donk, E.; Kairesalo, T.; Hietala, J.; Stephen, D.; Balayla, D.; Moss, B.

    2008-01-01

    Replicated, factorial mesocosm experiments were conducted across Europe to study the effects of nutrient enrichment and fish density on macrophytes and on periphyton chlorophyll a (chl-a) with regard to latitude. Periphyton chl-a densities and plant decline were significantly related to nutrient

  5. Evidence for Interactions between Surface Water and Periphyton Biofilms in Artificial Streams

    Science.gov (United States)

    Studies suggest that periphyton in streambeds can harbor fecal indicator bacteria (FIB) and, under certain circumstances, can be transferred from the periphyton biofilm into the surface water. An indoor mesocosm study was conducted at the U.S. Environmental Protection Agency Expe...

  6. Epilithic algae from caves of the Krakowsko-Częstochowska Upland (Southern Poland

    Directory of Open Access Journals (Sweden)

    Joanna Czerwik-Marcinkowska

    2011-01-01

    Full Text Available This paper describes the first study of algae assemblages in 20 caves in the Krakowsko-Częstochowska Upland (Southern Poland, in the period between 2005-2006. The investigations showed mostly on epilithic algae and their subaeric habitats (rock faces within caves and walls at cave entrances. The morphological and cytological variability of algae were studied in fresh samples, in cultures grown on agar plates and in SPURR preparations. A total of 43 algae species was identified, mostly epilithic species and tolerant of low light intensities. The largest group was formed by representatives of the division Chlorophyta (24 species, and then the division Chrysophyta (Heterokontophyta - 17 species, with 9 species belonging to the class Bacillariophyceae, 7 species - Xanthophyceae and 1 species representing the class Eustigmatophyceae. Dinophyta (2 species constituted the last and the smallest group. Among the collected algae, the following species deserve special attention: Thelesphaera alpina, Bracteacoccus minor, Trachychloron simplex, Tetracystis intermedia and T. cf. isobilateralis. The last species was not earlier found in Europe. Identification of species was greatly aided by examination of cell ultrastructure, which provided an array of further features, increasing chances of correct species identification. Furthermore, the studies focused that algae, although usually remaining under dominance of cyanobacteria, excellently differentiate this special area and even enrich it.

  7. Nonlinear Relationship of Near-Bed Velocity and Growth of Riverbed Periphyton

    Directory of Open Access Journals (Sweden)

    Mohamed Ateia

    2016-10-01

    Full Text Available Artificial streams were set up to test the relationship between near-bed water velocity and periphyton growth. Periphyton community samples collected from a Japanese stream were incubated for 44 days under a light intensity of 252 ± 72 μmol·photons/m2·s, a temperature of 20–25 °C, and three near-bed water velocity classes: low (<17.9 cm/s, moderate (17.9–32.8 cm/s, and high (>32.8 cm/s. A logistic model was applied to estimate the maximum net growth rate (μmax and carrying capacity (Bmax. A response surface method was also applied to estimate chlorophyll a (Chl-a and ash-free dry mass (AFDM with respect to the independent variables (i.e., time and water velocity. We detected both the highest μmax (1.99 d−1 and highest Bmax (7.01 mg/m2 for Chl-a at the moderate water velocity. For AFDM, we observed the highest μmax (0.57 d−1 and Bmax (1.47 g/m2 at the low and moderate velocity classes, respectively. The total algae density in the region of moderate velocity at the end of the experiment was 6.47 × 103 cells/cm2, corresponding to levels 1.7 and 1.3 times higher than those at lower and higher velocities, respectively. Our findings indicated that the moderate near-bed water velocity provided favorable conditions for algal growth and corresponding biomass accumulation.

  8. Light modulated toxicity of isoproturon toward natural stream periphyton photosynthesis: a comparison between constant and dynamic light conditions.

    Science.gov (United States)

    Laviale, Martin; Prygiel, Jean; Créach, Anne

    2010-05-10

    This study tested if a variation in light intensity, in comparison to constant light required in well-designed toxicity test, could have measurable consequences on the sensitivity of phototrophic biofilms (periphyton) to isoproturon. Two independent experiments were carried out to investigate the combined effects of light and isoproturon on the photochemical behavior of intact natural biofilms by measurements of chlorophyll fluorescence and pigment composition. Experiment 1 consisted of exposing biofilms to series of isoproturon concentrations (0-2 mg L(-1)) for 7 h under constant light at different irradiance levels (25-300 micromol m(-2) s(-1)). In experiment 2, biofilms were exposed using more environmentally realistic conditions to three selected concentrations of isoproturon (2, 6 and 20 microg L(-1)) during a 7-h-simulated daily light cycle. Our results demonstrated that light, considered here as a direct physical stressor, slightly modulated the acute toxicity of isoproturon on these diatom dominated communities. This was attributed to the fact that these two factors act specifically on the photosynthetic activity. Furthermore, it was shown that a dynamic light regime increased periphyton sensitivity to isoproturon by challenging its photoprotective mechanisms such as the xanthophyll cycle, therefore implying that traditional ecotoxicological bioassays lead to underestimate the effect of isoproturon. 2010 Elsevier B.V. All rights reserved.

  9. EXPERIMENTAL EFFECTS OF CONDUCTIVITY AND MAJOR IONS ON STREAM PERIPHYTON - abstract

    Science.gov (United States)

    Our study examined if specific conductivities comprised of different ions associated with resource extraction affected stream periphyton assemblages, which are important sources of primary production. Sixteen artificial streams were dosed with two ion recipes intended to mimic so...

  10. Cadmium speciation and accumulation in periphyton in a small stream with dynamic concentration variations

    Energy Technology Data Exchange (ETDEWEB)

    Bradac, Philippe [Eawag, Swiss Federal Institute of Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf (Switzerland); ETH, Swiss Federal Institute of Technology, Department of Environmental Sciences, CH-8092 Zurich (Switzerland); Wagner, Bettina; Kistler, David; Traber, Jacqueline; Behra, Renata [Eawag, Swiss Federal Institute of Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf (Switzerland); Sigg, Laura, E-mail: laura.sigg@eawag.c [Eawag, Swiss Federal Institute of Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf (Switzerland); ETH, Swiss Federal Institute of Technology, Department of Environmental Sciences, CH-8092 Zurich (Switzerland)

    2010-03-15

    Accumulation of cadmium in periphyton was investigated under field conditions while Cd concentration and speciation were dynamically varying in a small stream during rain events. Speciation in water was determined in situ by diffusion gradient in thin-films (DGT) and by modeling of complexation with fulvic acids. During the rain events, dissolved Cd concentrations increased from 0.17 nM to 0.27-0.36 nM, and 70-97% were DGT-labile. Cd content in periphyton closely followed Cd concentrations in water, despite higher concentrations of Zn and Mn, and may be controlled by either free or DGT-labile Cd concentrations. Decrease of Cd content in periphyton after the rain events was slower than the decrease of Cd concentration in water. Concentrations of Zn, Mn, Cu, Pb and Fe in periphyton also followed the dynamic variations of metal concentrations in water. Repeated exposure of periphyton to elevated dissolved Cd may lead to Cd accumulation. - Cadmium accumulation in periphyton was examined in a small stream during rain events in relation to Cd speciation.

  11. Nutrient capture and recycling by periphyton attached to modified agrowaste carriers.

    Science.gov (United States)

    Wan, Juanjuan; Liu, Xuemei; Wu, Chenxi; Wu, Yonghong

    2016-04-01

    The reuse of periphytic biofilm from traditional wastewater treatment (i.e., active sludge process) is inefficient to recycle nutrients due to low accumulation of nutrients. Then, in this study, peanut shell (PS), rice husk (RH), decomposed peanut shell (DPS), acidified rice husks (ARH), and a commonly used carrier-ceramsite (C, as the control)-were used to support the growth of periphyton. Results showed that DPS and ARH supported significantly higher periphyton biomass and metabolic versatility than PS and RH, respectively, due to the increased presence of positive groups. The total nitrogen (TN) and total phosphorus (TP) captured by periphyton were enhanced by 600-657 and 833-3255 % for DPS, and 461-1808 and 21-308 % for ARH, respectively. The removal of nutrients from simulated eutrophic surface waters using periphyton attached to DPS was improved by 24-47 % for TP, 12-048 % for TN, and 15-78 % for nitrate compared to the control. The results indicate that the periphyton attached to modified agrowaste was capable of efficiently entrapping and storing N and P from eutrophic water. This study also implies that the mixture of periphyton and the modified agrowaste carriers are promising raw materials of biofertilizer.

  12. Cadmium speciation and accumulation in periphyton in a small stream with dynamic concentration variations

    International Nuclear Information System (INIS)

    Bradac, Philippe; Wagner, Bettina; Kistler, David; Traber, Jacqueline; Behra, Renata; Sigg, Laura

    2010-01-01

    Accumulation of cadmium in periphyton was investigated under field conditions while Cd concentration and speciation were dynamically varying in a small stream during rain events. Speciation in water was determined in situ by diffusion gradient in thin-films (DGT) and by modeling of complexation with fulvic acids. During the rain events, dissolved Cd concentrations increased from 0.17 nM to 0.27-0.36 nM, and 70-97% were DGT-labile. Cd content in periphyton closely followed Cd concentrations in water, despite higher concentrations of Zn and Mn, and may be controlled by either free or DGT-labile Cd concentrations. Decrease of Cd content in periphyton after the rain events was slower than the decrease of Cd concentration in water. Concentrations of Zn, Mn, Cu, Pb and Fe in periphyton also followed the dynamic variations of metal concentrations in water. Repeated exposure of periphyton to elevated dissolved Cd may lead to Cd accumulation. - Cadmium accumulation in periphyton was examined in a small stream during rain events in relation to Cd speciation.

  13. Temporal and geographical distributions of epilithic sodium dodecyl sulfate-degrading bacteria in a polluted South Wales river

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.J.; Day, M.J.; Russell, N.J.; White, G.F.

    1988-02-01

    Epilithic bacteria were isolated nonselectively from riverbed stones and examined by gel zymography for their ability to produce alkylsulfatase (AS) enzymes and thus to metabolize alkyl sulfate surfactants such as sodium dodecyl sulfate. The percentages of AS+ isolates from stone epilithon at five sites from the source to the river mouth were measured on five sampling days spread over 1 year. The results showed that (i) the prevalence of epilithic AS+ strains (as a percentage of all isolates) was much higher at polluted sites than at the source; (ii) when averaged over the whole river, percentages of AS+ strains were significantly higher at the end of summer compared with either the preceding or the following winter; (iii) analysis of site-sampling time interactions indicated that water quality factors (e.g., biochemical oxygen demand and dissolved oxygen concentration) rather than climatic factors determined the distributions of epilithic AS+ isolates; (iv) constitutive strains were the most prevalent (7.2% of all isolates), with smaller numbers of isolates with inducible (4.5%) and repressible (1.7%) enzymes.

  14. Cyanobacteria enhance methylmercury production: a hypothesis tested in the periphyton of two lakes in the Pantanal floodplain, Brazil.

    Science.gov (United States)

    Lázaro, Wilkinson L; Guimarães, Jean Remy D; Ignácio, Aurea R A; Da Silva, Carolina J; Díez, Sergi

    2013-07-01

    The toxic potential of mercury (Hg) in aquatic systems is due to the presence and production of methylmercury (MeHg). Recent studies in tropical floodplain environments showed that periphyton associated with the roots of aquatic macrophytes produce MeHg. Periphyton communities are the first link in the food chain and one of the main MeHg sources in aquatic environments. The aim of this work was to test the hypotheses that the algal community structure affects potential methylation, and ecologically distinct communities with different algal and bacterial densities directly affect the formation of MeHg in the roots of macrophytes. To evaluate these, net MeHg production in the roots of Eichhornia crassipes in relation to the taxonomic structure of associated periphytic algae was evaluated. Macrophyte root samples were collected in the dry and flood season from two floodplain lakes in the Pantanal (Brazil). These lakes have different ecological conditions as a function of their lateral hydrological connectivity with the Paraguay River that is different during times of drought. Results indicated that MeHg production was higher in the flood season than in the dry season. MeHg production rates were higher in the disconnected lake in comparison to the connected lake during the dry season. MeHg production exhibited a strong positive co-variation with cyanobacteria abundance (R(2)=0.78; pcyanobacteria are associated with higher rates of methylation in aquatic systems. This suggests that cyanobacteria could be a proxy for sites of MeHg production in some natural aquatic environments. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Different Heavy Metal Accumulation Strategies of Epilithic Lichens Colonising Artificial Post-Smelting Wastes.

    Science.gov (United States)

    Rola, Kaja; Osyczka, Piotr; Kafel, Alina

    2016-02-01

    Lichens appear to be essential and effective colonisers of bare substrates including the extremely contaminated wastes of slag dumps. This study examines the metal accumulation capacity of epilithic lichens growing directly on the surface of artificial slag sinters. Four species representing different growth forms, i.e., crustose Candelariella aurella, Lecanora muralis, and Lecidea fuscoatra and fruticose Stereocaulon nanodes, were selected to evaluate the relationships between zinc, lead, cadmium, and nickel contents in their thalli and host substrates. Bioaccumulation factors of examined crustose lichens showed their propensity to hyperaccumulate heavy metals. Contrarily, concentrations of metals in fruticose thalli of S. nanodes were, as a rule, lower than in the corresponding substrates. This indicates that the growth form of thalli and degree of thallus adhesion to the substrate has a significant impact on metal concentrations in lichens colonising post-smelting wastes. Nonlinear regression models described by power functions show that at greater levels of Pb concentration in the substrate, the ability of C. aurella, L. muralis and L. fuscoatra to accumulate the metal experiences a relative decrease, whereas hyperbolic function describes a similar trend in relation to Ni content in S. nanodes. This phenomenon may be an important attribute of lichens that facilitates their colonisation of the surface of slag wastes.

  16. The effects of periphyton, fish and fertilizer dose on biological processes affecting water quality in earthen fish ponds.

    NARCIS (Netherlands)

    Milstein, A.; Azim, M.E.; Wahab, M.A.; Verdegem, M.C.J.

    2003-01-01

    The potential of periphyton-based aquaculture in South Asia is under investigation in an extensive research program. This paper is a further analysis of data from four experiments carried out in that framework, to explore periphyton, fish and fertilizer dose effects on water quality. Factor analysis

  17. Comparison of Cultural and Molecular Fecal Indicator Measurements in Surface Water and Periphyton Biofilms in Artificial Streams

    Science.gov (United States)

    Studies suggest that periphyton in streambeds can harbor fecal indicator bacteria (FIB) and, under certain circumstances, can be transferred from the periphyton biofilm into the surface water. An indoor mesocosm study was conducted at the U.S. Environmental Protection Agency Expe...

  18. ‘Sticky business’: The influence of streambed periphyton on particle deposition and infiltration

    Science.gov (United States)

    Salant, Nira L.

    2011-03-01

    Strong feedbacks exist between physical and ecological components of aquatic systems. Aquatic plants can alter flow and sedimentation patterns, in turn influencing habitat condition and organism responses. In this study, I investigate the interactions between streambed periphyton, particle deposition and infiltration, and flow hydraulics to determine the influence of these organisms on the local environment. In a series of flume experiments, I measured the effects of two contrasting forms of periphyton at several densities and growth stages on near-bed hydraulics, particle loss from the water column, surface deposition, and subsurface infiltration. Data show that periphyton assemblages altered the rate and quantity of particle deposition via several mechanisms, including shear stress modification, surface adhesion, and bed clogging. Although trends varied for different size classes within a suspension of fine sediment, diatoms and algae had distinctly different effects on hydraulics, deposition, and infiltration. In general, diatoms increased the rate of decline in suspended particle concentrations relative to non-periphyton surfaces by reducing shear stresses and enhancing surface deposition via adhesion. Increases in diatom biomass, however, reduced the quantity and depth of particle infiltration, presumably by clogging interstitial pore spaces, in turn lowering rates of concentration decline. In contrast, all algal growth stages had slower or similar rates of concentration decline compared to non-periphyton conditions, due to partial clogging by high biomass and a lack of adhesion at the bed surface. Clogging effects were counteracted at later growth stages, however, as late-stage algal structures increased shear stresses and downward advection, in turn increasing amounts of infiltration. Compiled data from several field studies and experiments demonstrate a positive relation between periphyton biomass and inorganic mass, but also show a wide range in the

  19. Historical and current atmospheric deposition to the epilithic lichen Xanthoparmelia in Maricopa County, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Zschau, T.; Getty, S.; Gries, C.; Ameron, Y.; Zambrano, A.; Nash, T.H

    2003-09-01

    Spatial variation of elemental deposition to lichen receptors across Maricopa County, Arizona, USA is documented for 1998 and historical trends relative to 1974 are documented. - Spatial patterns of atmospheric deposition of trace elements to an epilithic lichen were assessed using a spatial grid of 28 field sites in 1998 throughout Maricopa County, Arizona, USA. In addition, samples of Xanthoparmelia spp. from Arizona State University lichen herbarium material (1975-1976) was utilized for a limited number of sites in order to explore temporal trends. The lichen material was cleaned, wet digested and analyzed by ICP-MS for a suite of elemental concentrations [antimony (Sb), cadmium (Cd), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu), dysprosium (Dy), europium (Eu), gadolinium (Gd), gold (Au), holmium (Ho), lead (Pb), lutetium (Lu), neodymium (Nd), nickel (Ni), palladium (Pd), platinum (Pt), praseodymium (Pr), samarium (Sm), scandium (Sc), silver (Ag), terbium (Tb), thulium (Tm), tin (Sn), uranium (U), ytterbium (Yb), yttrium (Y), and zinc (Zn)]. Cluster analysis and principal component analysis suggest three major factors, which, depending on regional aerosol fractionation, explain most of the variation in elemental signatures: (1) a group of widely distributed rare earth elements (2) a highly homogenous Co, Cr, Ni, and Sc component representing the influence of mafic rocks, and (3) anthropogenic emissions. Elemental concentrations in Maricopa County lichens were generally comparable to those reported for relatively unpolluted areas. Only highly urbanized regions, such as the greater Phoenix Metropolitan Area and the NW corner of the county, exhibited elevated concentrations for Zn, Cu, Pb, and Cd. Lead levels in lichens have fallen over the last 30 years by 71%, while Zn concentrations for some regions have increased by as much as 245%. From the spatial pattern of elemental deposition for Cd, Cu, Ni, Pr, Pb, and Cu, we infer that agriculture, mining

  20. Historical and current atmospheric deposition to the epilithic lichen Xanthoparmelia in Maricopa County, Arizona

    International Nuclear Information System (INIS)

    Zschau, T.; Getty, S.; Gries, C.; Ameron, Y.; Zambrano, A.; Nash, T.H.

    2003-01-01

    Spatial variation of elemental deposition to lichen receptors across Maricopa County, Arizona, USA is documented for 1998 and historical trends relative to 1974 are documented. - Spatial patterns of atmospheric deposition of trace elements to an epilithic lichen were assessed using a spatial grid of 28 field sites in 1998 throughout Maricopa County, Arizona, USA. In addition, samples of Xanthoparmelia spp. from Arizona State University lichen herbarium material (1975-1976) was utilized for a limited number of sites in order to explore temporal trends. The lichen material was cleaned, wet digested and analyzed by ICP-MS for a suite of elemental concentrations [antimony (Sb), cadmium (Cd), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu), dysprosium (Dy), europium (Eu), gadolinium (Gd), gold (Au), holmium (Ho), lead (Pb), lutetium (Lu), neodymium (Nd), nickel (Ni), palladium (Pd), platinum (Pt), praseodymium (Pr), samarium (Sm), scandium (Sc), silver (Ag), terbium (Tb), thulium (Tm), tin (Sn), uranium (U), ytterbium (Yb), yttrium (Y), and zinc (Zn)]. Cluster analysis and principal component analysis suggest three major factors, which, depending on regional aerosol fractionation, explain most of the variation in elemental signatures: (1) a group of widely distributed rare earth elements (2) a highly homogenous Co, Cr, Ni, and Sc component representing the influence of mafic rocks, and (3) anthropogenic emissions. Elemental concentrations in Maricopa County lichens were generally comparable to those reported for relatively unpolluted areas. Only highly urbanized regions, such as the greater Phoenix Metropolitan Area and the NW corner of the county, exhibited elevated concentrations for Zn, Cu, Pb, and Cd. Lead levels in lichens have fallen over the last 30 years by 71%, while Zn concentrations for some regions have increased by as much as 245%. From the spatial pattern of elemental deposition for Cd, Cu, Ni, Pr, Pb, and Cu, we infer that agriculture, mining

  1. Hydrophysical conditions and periphyton in natural rivers. Analysis and predictive modelling of periphyton by changed regulations; Hydrofysiske forhold og begroing i naturlige elver. Analyse og prediktiv modellering av begroing ved reguleringsendringer

    Energy Technology Data Exchange (ETDEWEB)

    Stokseth, S

    1994-10-01

    The objective of this thesis has been to examine the interaction between hydrodynamical and physical factors and the temporal and spatial dynamics of periphyton in natural steep rivers. The study strategy has been to work with quantitative system variables to be able to evaluate the potential usability of a predictive model for periphyton changes as a response to river regulations. The thesis is constituted by a theoretical and an empirical study. The theoretical study is aimed at presenting a conceptual model of the relevant factors based on an analysis of published studies. Effort has been made to evaluate and present the background material in a structured way. To concurrently handle the spatial and temporal dynamics of periphyton a new method for data collection has been developed. A procedure for quantifying the photo registrations has been developed. The simple hydrodynamical parameters were estimated from a set of standard formulas whereas the complex parameters were estimated from a three dimensional simulation model called SSIIM. The main conclusion from the analysis is that flood events are the major controlling factors wrt. periphyton biomass and that water temperature is of major importance for the periphyton resistance. Low temperature clearly increases the periphyton erosion resistance. Thus, to model or control the temporal dynamics the river periphyton, the water temperature and the frequency and size of floods should be regarded the most significant controlling factors. The data in this study has been collected from a river with a stable water quality and frequent floods. 109 refs., 41 figs., 34 tabs.

  2. Entrapped Sediments as a Source of Phosphorus in Epilithic Cyanobacterial Proliferations in Low Nutrient Rivers

    Science.gov (United States)

    Wood, Susanna A.; Depree, Craig; Brown, Logan; McAllister, Tara; Hawes, Ian

    2015-01-01

    Proliferations of the benthic mat-forming cyanobacteria Phormidium have been reported in rivers worldwide. Phormidium commonly produces natural toxins which pose a health risk to animal and humans. Recent field studies in New Zealand identified that sites with Phormidium proliferations consistently have low concentrations of water column dissolved reactive phosphorus (DRP). Unlike other river periphyton, Phormidium mats are thick and cohesive, with water and fine sediment trapped in a mucilaginous matrix. We hypothesized that daytime photosynthetic activity would elevate pH inside the mats, and/or night time respiration would reduce dissolved oxygen. Either condition could be sufficient to facilitate desorption of phosphates from sediment incorporated within mats, thus allowing Phormidium to utilize it for growth. Using microelectrodes, optodes and pulse amplitude modulation fluorometry we demonstrated that photosynthetic activity results in elevated pH (>9) during daytime, and that night-time respiration causes oxygen depletion (river water and this, together with elevated concentrations of elements, including iron, suggest phosphorus release from entrapped sediment. Sequential extraction of phosphorus from trapped sediment was used to investigate the role of sediment at sites on the Mangatainoka River (New Zealand) with and without Phormidium proliferations. Deposition of fine sediment (sediment can provide a source of phosphorus to support Phormidium growth and proliferation. PMID:26479491

  3. Notes on epilithic and epigeic lichens from granite and gneiss outcrops in mountains of Makedonia, Greece, with emphasis on northern species

    DEFF Research Database (Denmark)

    Christensen, Steen

    2014-01-01

    The epilithic and epigeic lichen flora of eight localities with granite and gneiss outcrops in the mountains of Makedonia, N Greece has been investigated. Of the 46 taxa reported, seven species are new to Greece, viz.: Brodoa oroarcti­ca, Candelariella coralliza, Cetraria ericetorum, Lecanora...

  4. Some aspects of water quality in a polluted lowland river in relation to the intracellular chemical levels in planktonic and epilithic diatoms.

    Science.gov (United States)

    Tien, Chien-Jung

    2004-04-01

    Changes in elemental concentrations of diatoms and river water from the river Erh-Jen were determined using scanning electron microscopy energy-dispersive X-ray microanalysis and inductively coupled plasma mass spectrometry. Relatively large amounts of copper and lead found in both planktonic and epilithic diatoms implied these algae might play an important role in biogeochemical cycles and in the transfer of those elements to higher trophic levels in the aquatic environment. Changes in elemental concentrations within diatom cells were found to vary with other elements within cells and the same or different elements in water. Planktonic and epilithic cells showed different correlation patterns. For epilithic diatoms, negative correlations were found between concentrations of total phosphorus and phosphate in water and those of phosphorus within cells, and between concentrations of lead in water and in cells. Concentrations of chromium and mercury within planktonic cells and those of phosphorus, manganese and lead within epilithic ones were found to be easily influenced by other elements in river water, indicating appearance of the competitive manner on uptake of such elements by algal cells. Relatively high concentration factors (CFs) for cadmium, mercury and lead by diatoms in this study suggested they are good accumulators for these heavy metals. Significant negative corrections were found between the CFs of diatoms and the concentrations of elements in river water.

  5. Periphyton density is similar on native and non-native plant species

    NARCIS (Netherlands)

    Grutters, B.M.C.; Gross, Elisabeth M.; van Donk, E.; Bakker, E.S.

    2017-01-01

    Non-native plants increasingly dominate the vegetation in aquatic ecosystems and thrive in eutrophic conditions. In eutrophic conditions, submerged plants risk being overgrown by epiphytic algae; however, if non-native plants are less susceptible to periphyton than natives, this would contribute to

  6. Substratum as a driver of variation in periphyton chlorophyll and productivity in lakes

    DEFF Research Database (Denmark)

    Vadeboncoeur, Y.; Kalff, J.; Christoffersen, Kirsten Seestern

    2006-01-01

    content of periphyton on hard substrata (rocks and wood) was positively related to water-column total P (TP), whereas chlorophyll content of algae on sediment (epipelon) and TP were not significantly related. Chlorophyll content was up to 100× higher on sediments than on hard substrata. Within regions...... of the littoral zones in nutrient and energy cycles in lakes....

  7. EFFECTS OF A COASTAL GOLF COMPLEX ON WATER QUALITY, PERIPHYTON, AND SEAGRASS.

    Science.gov (United States)

    The objective of this study was to determine the effects of a golf course complex on water quality, colonized periphyton and seagrass meadows in adjacent freshwater, near-coastal and wetland areas. The environmental impact of the recreational facility, which uses spray wastewater...

  8. Water quality in simulated eutrophic shallow lakes in the presence of periphyton under different flow conditions.

    Science.gov (United States)

    Chen, Shu; Yang, Guolu; Lu, Jing; Wang, Lei

    2018-02-01

    Although the effects of periphyton on water quality and its relationship with flow conditions have been studied by researchers, our understanding about their combined action in eutrophic shallow lakes is poor. In this research, four aquatic model ecosystems with different water circulation rates and hydraulic conditions were constructed to investigate the effect of periphyton and flow condition on water quality. The concentrations of NH 4 + , TP, and chlorophyll-a and flow conditions were determined. The results show that, as a result of the rising nutrient level at the early stage and the decline in the lower limit, the presence of periphyton can make the ecosystem adaptable to a wider range of nutrients concentration. In terms of the flow condition, the circulation rate and hydraulic condition are influential factors for aquatic ecosystem. Higher circulation rate in the ecosystem, on one hand, facilitates the metabolism by accelerating nutrient cycling which is beneficial to water quality; on the other hand, high circulation rate leads to the nutrient lower limit rising which is harmful to water quality improvement. At low velocities, slight differences in hydraulic conditions, vertical velocity gradient and turbulence intensity gradient could affect the quantity of phytoplankton. Our study suggests that, considering environmental effect of periphyton, flow conditions and their combined action is essential for water quality improvement and ecological restoration in eutrophic shallow lakes.

  9. Effects of bromacil, diuron, glyphosate, and sulfometuron-methyl on periphyton assemblages and rainbow trout : final report.

    Science.gov (United States)

    2003-01-01

    This study documents the testing of several common herbicides used by the Oregon Department of Transportation in vegetation management. The project assessed the short- and long-term effects of Roundup, Krovar and Oust on periphyton and rainbow trout....

  10. The influence of land use on water quality and diatom community ...

    African Journals Online (AJOL)

    Epilithic diatom communities offer a holistic and integrated approach for assessing water quality as they remain in one place for a number of months and reflect an ecological memory of water quality over a period of time. The objective of this study is to use diatom assemblages to distinguish between particular land types ...

  11. Complex and interactive effects of ocean acidification and temperature on epilithic and endolithic coral-reef turf algal assemblages

    Science.gov (United States)

    Johnson, Maggie D.; Comeau, Steeve; Lantz, Coulson A.; Smith, Jennifer E.

    2017-12-01

    Turf algal assemblages are ubiquitous primary producers on coral reefs, but little is known about the response of this diverse group to ocean acidification (OA) across different temperatures. We tested the hypothesis that CO2 influences the functional response of epilithic and endolithic turf assemblages to increasing temperature. Replicate carbonate plugs covered by turf were collected from the reef and exposed to ambient and high pCO2 (1000 µatm) conditions for 3 weeks. Each pCO2 treatment was replicated across six temperatures (24.0-31.5 °C) that spanned the full seasonal temperature range on a fringing reef in Moorea, French Polynesia, and included one warming treatment (3 °C above daily average temperatures). Temperature and CO2 enrichment had complex, and sometimes interactive, effects on turf metabolism and growth. Photosynthetic and respiration rates were enhanced by increasing temperature, with an interactive effect of CO2 enrichment. Photosynthetic rates were amplified by high CO2 in the warmest temperatures, while the increase in respiration rates with temperature were enhanced under ambient CO2. Epilithic turf growth rates were not affected by temperature, but increased in response to CO2 enrichment. We found that CO2 and temperature interactively affected the endolithic assemblage, with the highest growth rates under CO2 enrichment, but only at the warmest temperatures. These results demonstrate how OA may influence algal physiology and growth across a range of ecologically relevant temperatures, and indicate that the effects of CO2 enrichment on coral-reef turf assemblages can be temperature dependent. The complex effects of CO2 enrichment and temperature across a suite of algal responses illustrates the importance of incorporating multiple stressors into global change experiments.

  12. Morphology and ultrastructure of epilithic versus cryptic, microbial growth in lower Cambrian phosphorites from the Montagne Noire, France.

    Science.gov (United States)

    Alvaro, J J; Clausen, S

    2010-03-01

    The lower Cambrian grainy phosphorites of the northern Montagne Noire occur interbedded with grey to black, laminated to massive shales and limestones deposited along the edge of a continental shelf, associated with slope-related facies and unstable substrates. The concentration of phosphate took place by repeated alternations of low sedimentation rates and condensation (hardgrounds), in situ early-diagenetic precipitation of fluorapatite, winnowing and polyphase reworking of previously phosphatized skeletons and hardground-derived clasts. The succession of repeated cycles of sedimentation, phosphate concentration, and reworking led to multi-event phosphate deposits rich in allochthonous particles. Phosphogenesis was primarily mediated by microbial activity, which is evidenced by the abundance of phosphatized putative microbial remains. These occur as smooth and segmented filaments, sheaths, and ovoid-shaped coccoids. These simple morphologies commonly form composite frameworks as a result of their aggregation and entanglement, leading to the record of biofilms, microbial mats, and complex networks. These infested the calcitic skeletonized microfossils that littered the substrate. Microbial activity evidences epilithic (anisotropic coatings on skeletons), euendolithic (perforating skeletal walls), and cryptoendolithic (lining inter- and intraparticulate pores) strategies, the latter dominated by bundles of filaments and globular clusters that grew along the cavities of helcionellids and hyoliths. According to their epilithic versus cryptic strategies, microbial populations that penetrated and dwelled inside hard skeletal substrates show different network and colonial morphologies. These early Cambrian shell concentrations were the loci of a stepwise colonization made by saprophytic to mutualistic, cyanobacterial-fungal consortia. Their euendolithic and cryptoendolithic ecological niches provided microbial refugia to manage the grazing impact mainly led by metazoans.

  13. Succession of Periphyton and Phytoplankton Assemblages in Years with Varying Amounts of Precipitation in a Shallow Urban Lake (Lake Jeziorak Mały, Poland)

    OpenAIRE

    Zębek Elžbieta

    2014-01-01

    This study of periphyton assemblages (periphyton in separator pipes, epilithon and epiphyton) and phytoplankton was carried out in Lake Jeziorak Maly in 1997-2003 and 2005. Since precipitation amounts varied in these years, changes in the abundance, biomass, taxonomic group structure, spe-cies diversity and dominant taxa of these assemblages were analyzed in relation to the physical and chemical water parameters. The periphyton in pipes had their highest abundance and biomass at the mean prec...

  14. Twenty-five-year study of radionuclides in the Susquehanna river via periphyton biomonitors.

    Science.gov (United States)

    Patrick, Ruth; Palms, John; Kreeger, Danielle; Harris, Charles

    2007-01-01

    This 25-y study monitored aquatic and terrestrial gamma-ray-emitting radionuclide levels near a nuclear power plant. It is the only known, long-term environmental survey of its kind. It was conducted neither by a utility owner, nor by a government agency, but rather by a private, environmental research institution. Compared to dozens of other flora and fauna, periphyton was found to be the best indicator to biomonitor the Susquehanna River, which runs near PPL Susquehanna's nuclear plant. Sampling began in 1979 before the first plant start-up and continued for the next 24 years. Monitoring began two months after the Three Mile Island accident of 28 March 1979 and includes Three Mile Island area measurements. Ongoing measurements detected fallout from Chernobyl in 1986, as well as I not released from PPL Susquehanna. Although this paper concentrates on radionuclides found in periphyton, the scope of the entire environmental program includes a wide variety of aquatic and land-based plants, animals, and inorganic matter. Other species and matter studied were fish, mussels, snails, crayfish, insects, humus, mushrooms, lichens, squirrels, deer, cabbage, tomatoes, coarse and flocculated sediment, and more. Results show periphyton works well for detection of radionuclide activity, even in concentrations less than 100 Bq kg (picocuries per gram amounts). Data indicate that PPL Susquehanna's radionuclide releases have had no known environmental or human health impact.

  15. Assessment of water quality, benthic invertebrates, and periphyton in the Threemile Creek basin, Mobile, Alabama, 1999-2003

    Science.gov (United States)

    McPherson, Ann K.; Gill, Amy C.; Moreland, Richard S.

    2005-01-01

    The U.S. Geological Survey conducted a 4-year investigation of water quality and aquatic-community structure in Threemile Creek, an urban stream that drains residential areas in Mobile, Alabama. Water-quality samples were collected between March 2000 and September 2003 at four sites on Threemile Creek, and between March 2000 and October 2001 at two tributary sites that drain heavily urbanized areas in the watershed. Stream samples were analyzed for major ions, nutrients, fecal-indicator bacteria, and selected organic wastewater compounds. Continuous measurements of dissolved-oxygen concentrations, water temperature, specific conductance, and turbidity were recorded at three sites on Threemile Creek during 1999?2003. Aquatic-community structure was evaluated by conducting one survey of the benthic invertebrate community and multiple surveys of the algal community (periphyton). Benthic invertebrate samples were collected in July 2000 at four sites on Threemile Creek; periphyton samples were collected at four sites on Threemile Creek and the two tributary sites during 2000 ?2003. The occurrence and distribution of chemical constituents in the water column provided an initial assessment of water quality in the streams; the structure of the benthic invertebrate and algal communities provided an indication of the cumulative effects of water quality on the aquatic biota. Information contained in this report can be used by planners and resource managers in the evaluation of proposed total maximum daily loads and other restoration efforts that may be implemented on Threemile Creek. The three most upstream sites on Threemile Creek had similar water chemistry, characterized by a strong calcium-bicarbonate component; the most downstream site on Threemile Creek was affected by tidal fluctuations and mixing from Mobile Bay and had a strong sodium-chloride component. The water chemistry at the tributary site on Center Street was characterized by a strong sodium-chloride component

  16. Comparing two periphyton collection methods commonly used for stream bioassessment and the development of numeric nutrient standards.

    Science.gov (United States)

    Rodman, Ashley R; Scott, J Thad

    2017-07-01

    Periphyton is an important component of stream bioassessment, yet methods for quantifying periphyton biomass can differ substantially. A case study within the Arkansas Ozarks is presented to demonstrate the potential for linking chlorophyll-a (chl-a) and ash-free dry mass (AFDM) data sets amassed using two frequently used periphyton sampling protocols. Method A involved collecting periphyton from a known area on the top surface of variably sized rocks gathered from relatively swift-velocity riffles without discerning canopy cover. Method B involved collecting periphyton from the entire top surface of cobbles systematically gathered from riffle-run habitat where canopy cover was intentionally avoided. Chl-a and AFDM measurements were not different between methods (p = 0.123 and p = 0.550, respectively), and there was no interaction between method and time in the repeated measures structure of the study. However, significantly different seasonal distinctions were observed for chl-a and AFDM from all streams when data from the methods were combined (p methods may effectively be used together with some minor considerations due to potential confounding factors. This study provides motivation for the continued investigation of combining data sets derived from multiple methods of data collection, which could be useful in stream bioassessment and particularly important for the development of regional stream nutrient criteria for the southern Ozarks.

  17. Experimental investigations for controlling periphyton in regulated rivers; Eksperimentelle undersoekelser for kontroll av begroing i regulerte vassdrag

    Energy Technology Data Exchange (ETDEWEB)

    Lindstroem, E A; Bremnes, T; Johansen, S W

    1994-12-31

    Regulation of river courses may have several environmental effects. This report describes investigations in NIVA`s experimental troughs near Oset, Maridalsvannet, Oslo, Norway. The main topic is algae periphyton and benthic invertebrates, with different emphasis on the different components. In 1989 the problem of ``the impact of benthic invertebrates on algae periphyton`` was illuminated, and In 1990 the converse, ``the impact of algae periphyton on benthic invertebrates`` as well as the effects of various additives of readily available phosphorus on algae periphyton. It is found that small additions of phosphorus (0.5 {mu}g P/l) may lay the foundation for a dramatic increase in growth rate and biomass. Some groups of benthic invertebrates responded quickly to the increased mass of algae. In 1991 the research was concentrated on establishing algae periphyton over a long time, at various temperatures, with and without the addition of phosphorus. The results of three years of research form, with similar results from the literature, the foundation of certain conclusions about the conditions for the establishment of algae mass in running water. The report states five levels of phosphorus concentration which may develop different levels of biomass. At the highest levels the size of the biomass is described as ``problematic``. 100 refs., 55 figs., 97 tabs.

  18. Macrophytes and periphyton carbon subsidies to bacterioplankton and zooplankton in a shallow eutrophic lake in tropical China

    NARCIS (Netherlands)

    de Kluijver, A.; Ning, J.; Liu, Z.; Jeppesen, E.; Gulati, R.D.; Middelburg, J.J.

    The subsidy of carbon derived from macrophytes and associated periphyton to bacterioplankton and zooplankton in subtropical shallow eutrophic Huizhou West Lake in China was analyzed using carbon stable isotope signatures. A restored part of the lake dominated by macrophytes was compared with an

  19. Macrophytes and periphyton carbon subsidies to bacterioplankton and zooplankton in a shallow eutrophic lake in tropical China

    NARCIS (Netherlands)

    de Kluijver, A.; Ning, J.; Liu, Z.; Jeppesen, E.; Gulati, R.D.; Middelburg, J.J.

    2015-01-01

    The subsidy of carbon derived from macrophytes and associated periphyton to bacterioplankton and zooplankton in subtropical shallow eutrophic Huizhou West Lake in China was analyzed using carbon stable isotope signatures. A restored part of the lake dominated by macrophytes was compared with an

  20. Stable nitrogen isotope ratios of macrophytes and associated periphyton along a nitrate gradient in two subtropical, spring-fed streams

    DEFF Research Database (Denmark)

    De Brabandere, Loreto; Frazer, Thomas K.; Montoya, Joseph P.

    2007-01-01

    , macrophytes and periphyton as a consequence of isotopic fractionation associated with preferential use of 14NO3-. This hypothesis was tested in two spring-fed river systems, the Chassahowitzka and Homosassa rivers, along Florida’s central Gulf of Mexico coast. 3. In general, d15N values of nitrate...

  1. Spatial and temporal variations of Cocconeis placentula var. euglypta (Ehrenb. 1854 Grunow, 1884 in drift and periphyton

    Directory of Open Access Journals (Sweden)

    EN. Gari

    Full Text Available Spatial and temporal variations of Cocconeis placentula var. euglypta in drift and periphyton were studied in mountain streams of the Córdoba Province (Argentina. The sampling program was conducted in study sites located on a confluence between different order streams during an annual cycle. Samples were also taken every two hours during the daylight period in high and low water conditions. The relationship between drift and cellular reproduction was evaluated by valve length biometrics analysis. C. placentula var. euglypta drift was continuous; its density was not always dependent on periphyton density in each locality. C. placentula var. euglypta drift could be related to abiotic factors such as temperature and flow during the annual cycle. There were significant differences between periphyton and drift valve lengths. Moreover, drift can be associated with cellular reproduction because density was higher when valve lengths were shorter at different hours of the day. C. placentula var. euglypta epiphytims on Cladophora glomerata also influenced drift density and size distribution, modifying the relationship between periphyton and drift during the late spring when C. placentula var. euglypta was detached from senescent mats.

  2. Influence of periphyton substrates and rearing density on Liza aurata growth and production in marine nursery ponds

    NARCIS (Netherlands)

    Richard, M.; Maurice, J.T.; Anginot, A.; Paticat, F.; Verdegem, M.C.J.; Hussenot, J.M.E.

    2010-01-01

    The main objectives of this investigation were to test the effects of (i) the presence of periphyton substrates, (ii) rearing density and (iii) supplemental feeding with dry feed on the growth and production of golden mullet (Liza aurata) juveniles. Twenty-six 1 m2-cages were installed in a French

  3. C/N-controlled periphyton-based freshwater prawn farming system: a sustainable approach to increase pond productivity

    NARCIS (Netherlands)

    Asaduzzaman, M.

    2012-01-01

    Three technologies showed to improve productivity and sustainability of pond production: (1) C/N ratio control, (2) providing substrates for periphyton development, and (3) fish driven re-suspension. The novelty of this PhD research is to combine these technologies, with the goal to raise pond

  4. Atmospheric transport of urban-derived NHx: Evidence from nitrogen concentration and δ15N in epilithic mosses at Guiyang, SW China

    International Nuclear Information System (INIS)

    Liu Xueyan; Xiao Huayun; Liu Congqiang; Li Youyi; Xiao Hongwei

    2008-01-01

    Nitrogen concentration and δ 15 N in 175 epilithic moss samples were investigated along four directions from urban to rural sites in Guiyang, SW China. The spatial variations of moss N concentration and δ 15 N revealed that atmospheric N deposition is dominated by NH x -N from two major sources (urban sewage NH 3 and agricultural NH 3 ), the deposition of urban-derived NH x followed a point source pattern characterized by an exponential decline with distance from the urban center, while the agricultural-derived NH x was shown to be a non-point source. The relationship between moss N concentration and distance (y = 1.5e -0.13x + 1.26) indicated that the maximum transporting distance of urban-derived NH x averaged 41 km from the urban center, and it could be determined from the relationship between moss δ 15 N and distance [y = 2.54 ln(x) - 12.227] that urban-derived NH x was proportionally lower than agricultural-derived NH x in N deposition at sites beyond 17.2 km from the urban center. Consequently, the variation of urban-derived NH x with distance from the urban center could be modeled as y = 56.272e -0.116x - 0.481 in the Guiyang area. - Tissue N concentration and δ 15 N in epilithic mosses may be indicators for atmospheric transport of urban-derived NH x

  5. Technical evaluation of tilapia (Oreochromis niloticus) monoculture and tilapia-prawn (Macrobrachium rosenbergii) polyculture in earthen ponds with or without substrates for periphyton development

    NARCIS (Netherlands)

    Uddin, S.; Farzana, A.; Fatema, M.K.; Azim, M.E.; Wahab, M.A.; Verdegem, M.C.J.

    2007-01-01

    The effects of periphyton grown on bamboo substrate, on growth and production of Nile tilapia, Oreochromis niloticus (Genetically Improved Farmed Tilapia strain) in monoculture and polyculture with the freshwater prawn (Macrobrachium rosenbergii) were studied and economically evaluated. The

  6. Cadmium bioavailability to Hyalella azteca from a periphyton diet compared to an artificial diet and application of a biokinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Golding, Lisa A., E-mail: lisa.golding@csiro.au [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Borgmann, Uwe [Environment Canada, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada); George Dixon, D. [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2013-01-15

    Differences between the bioavailability of cadmium in a periphyton diet and an artificial laboratory diet (TetraMin{sup Registered-Sign }) have important consequences for predicting bioaccumulation and toxicity in the freshwater amphipod Hyalella azteca. The assimilation efficiency (AE) of Cd was compared between periphyton and TetraMin{sup Registered-Sign} at low (1510 and 358 nmol/g ash-free dry mass respectively) and chronically lethal (31,200 and 2890 nmol/g ash-free dry mass respectively) Cd concentrations and in fresh and dry forms using a {sup 109}Cd radiotracer pulse-chase feeding technique. Assimilation efficiency of Cd from periphyton (AE = 3-14%) was lower than that for TetraMin{sup Registered-Sign} (AE = 44-86%) regardless of Cd concentration or food form. Ingestion rate (IR) was lower for dry than fresh forms of periphyton (0.042 and 0.16 g AFDM/g H. azteca/day respectively) and TetraMin{sup Registered-Sign} (0.19 and 0.87 AFDM/g H. azteca/day respectively) and depuration rate (k{sub e}) did not differ statistically with food type, form or Cd concentration (0.032-0.094 d{sup -1}). Biokinetic models with parameters of AE, IR and k{sub e} were used to estimate bioaccumulation from the separate food types. These estimates were compared to those from an independent chronic Cd saturation bioaccumulation model. While the model estimates did not concur, a sensitivity analysis indicated that AE and IR were the most influential biokinetic model parameters for Cd in periphyton and TetraMin{sup Registered-Sign} respectively. It was hypothesized that AE was underestimated for Cd in periphyton due to a non-adapted gut enzyme system and IR was overestimated for Cd in TetraMin{sup Registered-Sign} due to an initial rapid ingestion phase in H. azteca's feeding habits. This research demonstrated the importance of using ecologically relevant food types in laboratory experiments and verifying acute biokinetic model predictions of dietary metal contribution with

  7. Assessing the influence of surface roughness on the epilithic colonisation of limestones by non-contact techniques

    Directory of Open Access Journals (Sweden)

    Miller, A. Z.

    2012-09-01

    Full Text Available The importance of stone colonisation by microorganisms has led to an extensive literature on mechanisms and rates of physicochemical degradation of stone surface, both in laboratory and field contexts. Biological colonisation of a stone surface depends on intrinsic stone parameters like mineral composition, texture, porosity, and permeability, as well as on environmental parameters. In the present study, quantification of stone surface roughness and its relationship to epilithic colonisation was demonstrated for three types of limestones throughout non-destructive techniques, namely optical surface roughness instrument and digital image analysis. According to the roughness average (Ra and mean roughness depth (Rz determined for Ançã limestone, Lioz limestone and Lecce stone, it can be concluded that great surface roughness stones render them prone to microbial colonisation.La colonización de la piedra por microorganismos ha generado una extensa literatura sobre los mecanismos y tasas de degradación fisicoquímica de las superficies pétreas, tanto en laboratorio como en estudios de campo. La colonización biológica de piedra de construcción depende de parámetros intrínsecos como son su composición mineral, textura, porosidad y permeabilidad, así como de parámetros ambientales. Este estudio demuestra la relación entre la rugosidad superficial de la piedra y la colonización epilítica, cuantificada en tres tipos de caliza mediante técnicas no destructivas: medida de la rugosidad superficial usando un perfilómetro óptico y análisis digital de imágenes. De acuerdo con la rugosidad media aritmética (Ra y la amplitud media de rugosidad (Rz, determinadas para la caliza de Ançã, la caliza de Lioz y la piedra de Lecce, puede concluirse que las piedras con alta rugosidad superficial son más propensas a la colonización microbiana.

  8. Impact of pumped-storage hydropower plant PVE Cierny Vah on transport of particulate organic matter and periphyton biomass

    International Nuclear Information System (INIS)

    Bokorova, L.; Kokavec, I.

    2015-01-01

    Although the Serial Discontinuity Concept (SDC) is supported by the results of scientific research, there are specific cases where changes in certain factors get opposite values. The aim of this work was to evaluate the effect of PVE Cierny Vah on POM and periphyton biomass. Below the PVE Cierny Vah was found more than 5- fold increase in periphyton biomass compared to the site above the dam, which was also reflected in the amount of BOM. Reservoir acts as a sediment trap, but PVE Cierny Vah on average captures nearly 30% of TOM. Therefore sedimentation takes place below the dam as well as above. The decrease in the POM ratio dowstream of the PVE Cierny Vah confirms the SDC hypothesis about the impact of the dam in the headwaters. Each reservoir is somewhat unique, and therefore, it is necessary to consider all factors potenti (authors)

  9. Effects of C/N controlled periphyton based organic farming of freshwater prawn on water quality parameters and biotic factors

    Directory of Open Access Journals (Sweden)

    Md. Rezoanul Haque

    2014-08-01

    Full Text Available The effects of C:N controlled periphyton based organic farming of freshwater prawn on water quality parameters and biotic factors were investigated. The experiment had two treatments: T1 and T2 each with three replications. Stocking density was maintained at 20,000 juveniles ha-1. In T1, only commercially available prawn feed was applied and in T2, a locally formulated and prepared feed containing 24% crude protein with C:N ratio close to 20 was used, and maize flour and bamboo side shoots were provided for maintaining C:N ratio 20.Mean values of water quality parameters did not vary significantly (P>0.05 between treatments. Periphytic biomass in terms of dry matter, ash free dry matter (AFDM and chlorophyll a showed significant difference (P<0.05 among different sampling months. Individual harvesting weight, individual weight gain, specific growth rates, gross and net yields of prawn were significantly higher (P<0.05 in T2 than T1. Therefore, it was concluded that freshwater prawn might consume periphyton biomass in C:N controlled periphyton based organic farming practices resulted a significantly (P<0.05 higher production of freshwater prawn than traditional farming.

  10. The use of epilithic Antarctic lichens (Usnea aurantiacoatra and U. antartica) to determine deposition patterns of heavy metals in the Shetland Islands, Antarctica.

    Science.gov (United States)

    Poblet, A; Andrade, S; Scagliola, M; Vodopivez, C; Curtosi, A; Pucci, A; Marcovecchio, J

    1997-11-27

    Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized.

  11. Effects of copper on species composition of periphyton in a Sierra Nevada, California, stream

    Energy Technology Data Exchange (ETDEWEB)

    Leland, H.V.; Carter, J.L.

    1984-06-01

    Changes in species composition of the periphyton of an oliotrophic, Sierra Nevada stream continuously dosed for 1 year at three concentrations of copper (2.5, 5 and 10..mu..g 1/sup -1/ Cu/sub T/; approximately 12, 25 and 50 ng 1/sup -1/ Cu/sup 2 +/) were determined. The numerically most abundant taxa were Bacillariophyceae (Achnanthes minutissima, Cocconeis placentula, Cymbella microcephala, C. sinuata, Fragilaria construens, F. crotonensis, Navicula spp., Synedra acus and S. rumpens), and the Cyanophyta Lynbya spp., a co-dominant during spring and summer. Population densities of Lyngbya spp. were markedly reduced at all test concentrations of copper. Population densities of the principal Chlorophyta (Spirogyra spp. and Cladophora spp.) and the diatom Amphipleura pellucida were reduced at 5 ..mu..g 1/sup -1/ Cu/sub T/. Of the twenty-two most abundant taxa, sixteen were reduced in abundance by continuous exposure to 10 ..mu..g 1/sup -1/ Cu/sub T/. There was no commensurate reduction in standing crop (total number of individuals of all taxa). Achnanthes minutissima, a co-dominant in the control, was the primary replacement species. Other taxa that were more abundant at 5 ..mu..g 1/sup -1/ Cu/sub T/ than in the control were Ceratoneis arcus, Cocconeis placentula, Navicula spp. and Synedra rumpens. Only A. minutissima and Calothrix spp. were more abundant at l10 ..mu..g 1/sup -1/ than in the control. Three resemblance measures (Canberra metric, Bray-Curtis and Dice) and diversity (Brillouin's) were evaluated for detecting differences in species composition among experimental stream sections. The Canberra metric, an index sensitive to proportional rather than absolute differences, was the most informative of these indices.

  12. The potential of mixed culture of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) and freshwater giant prawn (Macrobrachium rosenbergii) in periphyton-based systems

    NARCIS (Netherlands)

    Uddin, S.; Azim, M.E.; Wahab, M.A.; Verdegem, M.C.J.

    2006-01-01

    The production performance of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) in periphyton-based systems were studied in farmers' ponds at Mymensingh, Bangladesh. Fifteen ponds (200-300 m2 area and 1.0-1.5 m in depth) were used to

  13. Effects of stocking density of freshwater prawn Macrobrachium rosenbergii and addition of different levels of tilapia Oreochromis niloticus on production in C/N controlled periphyton based system

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Mondal, M.N.; Azim, M.E.

    2009-01-01

    An on-station trial was conducted to evaluate the effect of stocking density of freshwater prawn and addition of different levels of tilapia on production in carbon/nitrogen (C/N) controlled periphyton based system. The experiment had a 2 × 3 factorial design, in which two levels of prawn stocking

  14. Effects of addition of tilapia Oreochromis niloticus and substrates for periphyton developments on pond ecology and production in C/N-controlled freshwater prawn Macrobrachium rosenbergii farming systems

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Benerjee, S.; Akter, T.; Hasan, M.M.; Azim, M.E.

    2009-01-01

    The present research investigated the effect of addition of tilapia and substrates for periphyton development on pond ecology, production and economic performances in C/N controlled freshwater prawn farming system. The absence and presence (0 and 0.5 individual m- 2) of tilapia were investigated in

  15. Effects of organic pollution on biological communities of marine biofilm on hard substrata

    International Nuclear Information System (INIS)

    Sanz-Lázaro, C.; Fodelianakis, S.; Guerrero-Meseguer, L.; Marín, A.; Karakassis, I.

    2015-01-01

    We examined the effect of organic enrichment on diatom and bacterial assemblages of marine epilithic biofilms on two locations in the Mediterranean, one situated in Spain and the other in Greece. Total organic carbon, total organic nitrogen, stable isotopes (δ 13 C and δ 15 N) and chlorophyll a indicated significant incorporation of organic wastes, increased primary production and trophic niche modifications on the biofilms close to the organic enrichment source. In Spain, where the organic load was higher than in Greece, diatom and, to some extent, bacterial assemblages varied following the organic enrichment gradient. The taxonomic richness of diatom and bacterial communities was not influenced by organic enrichment. Classical community parameters showed consistent patterns to organic pollution in both locations, whereas community assemblages were only influenced when organic pollution was greatest. The successional patterns of these communities were similar to other epilithic communities. The modification of community assemblages induced by organic pollution may affect ecological functions. - Highlights: • We examined the effect of organic enrichment on assemblages of marine biofilms. • Classical community parameters showed consistent patterns to organic pollution. • Diatom and bacterial assemblages were affected under high level of organic enrichment. • Successional patterns were similar to other communities inhabiting hard substrata. • Assemblage modifications induced by organic pollution may affect ecological functions. - Organic pollution modifies the assemblages of biofilm communities which may affect important ecological functions

  16. Short-term responses to watershed logging on biomass mercury and methylmercury accumulation by periphyton in boreal lakes

    Energy Technology Data Exchange (ETDEWEB)

    Desrosiers, M.; Planas, D. [Quebec Univ., Montreal, PQ (Canada). Dept. de sciences biologiques; Mucci, A. [McGill Univ., Montreal, PQ (Canada). Dept. of Earth and Planetary Sciences

    2006-08-15

    Increased timber harvesting in the boreal regions of Quebec may have a significant impact on aquatic ecosystems. Watershed disturbances such as logging increase chemical loading to lakes. Soil in the Canadian Shield readily adsorbs and accumulates mercury (Hg) from atmospheric deposition. Forest watersheds serve as large reservoirs of Hg that shed their metal load when soil and land hydrology are disrupted. This paper presented the results of a study evaluating the impact of logging on periphyton algal biomass and dry mass. The study also evaluated the impact of total mercury (THG) and methylmercury (MeHg) accumulation in the littoral zone of the boreal lakes. A before-after control-impact (BACI) sample design was applied that required data from control and target sites sampled both before and after the disturbances. The study was carried out on 18 boreal lakes located in the Grenville geological province. Eight lakes had their watersheds logged over 15 to 79 per cent of their area. A further 10 lakes were used as control sites to document interannual variations. The project used water quality and physiographic data acquired by research groups within the Sustainable Forest Management Network. Fourteen study lakes were sampled once a year during 2 consecutive ice-free seasons before and after logging, and another 4 lakes were sampled 2 years after logging. Significant decreases in algal biomass and increases in MeHg concentrations in periphyton mats in a majority of the harvested watershed lakes were detected. The increases may have a significant impact on organisms of higher trophic levels as they are at the base of the food web. Results suggested that the observed decrease in periphyton biomass combined with the increase in MeHg accumulation may magnify the impact of logging activities on fish and other aquatic predators. Two years after logging, it was observed that MeHg concentrations were still increasing. It was concluded that further research is needed

  17. Microbial Biofilm Community Variation in Flowing Habitats: Potential Utility as Bioindicators of Postmortem Submersion Intervals

    Directory of Open Access Journals (Sweden)

    Jennifer M. Lang

    2016-01-01

    Full Text Available Biofilms are a ubiquitous formation of microbial communities found on surfaces in aqueous environments. These structures have been investigated as biomonitoring indicators for stream heath, and here were used for the potential use in forensic sciences. Biofilm successional development has been proposed as a method to determine the postmortem submersion interval (PMSI of remains because there are no standard methods for estimating the PMSI and biofilms are ubiquitous in aquatic habitats. We sought to compare the development of epinecrotic (biofilms on Sus scrofa domesticus carcasses and epilithic (biofilms on unglazed ceramic tiles communities in two small streams using bacterial automated ribosomal intergenic spacer analysis. Epinecrotic communities were significantly different from epilithic communities even though environmental factors associated with each stream location also had a significant influence on biofilm structure. All communities at both locations exhibited significant succession suggesting that changing communities throughout time is a general characteristic of stream biofilm communities. The implications resulting from this work are that epinecrotic communities have distinctive shifts at the first and second weeks, and therefore the potential to be used in forensic applications by associating successional changes with submersion time to estimate a PMSI. The influence of environmental factors, however, indicates the lack of a successional pattern with the same organisms and a focus on functional diversity may be more applicable in a forensic context.

  18. Pollution-Induced Community Tolerance To Diagnose Hazardous Chemicals in Multiple Contaminated Aquatic Systems.

    Science.gov (United States)

    Rotter, Stefanie; Gunold, Roman; Mothes, Sibylle; Paschke, Albrecht; Brack, Werner; Altenburger, Rolf; Schmitt-Jansen, Mechthild

    2015-08-18

    Aquatic ecosystems are often contaminated with large numbers of chemicals, which cannot be sufficiently addressed by chemical target analyses. Effect-directed analysis (EDA) enables the identification of toxicants in complex contaminated environmental samples. This study suggests pollution-induced community tolerance (PICT) as a confirmation tool for EDA to identify contaminants which actually impact on local communities. The effects of three phytotoxic compounds local periphyton communities, cultivated at a reference (R-site) and a polluted site (P-site), were assessed to confirm the findings of a former EDA study on sediments. The sensitivities of R- and P-communities to prometryn, tributyltin (TBT) and N-phenyl-2-naphthylamine (PNA) were quantified in short-term toxicity tests and exposure concentrations were determined. Prometryn and PNA concentrations were significantly higher at the P-site, whereas TBT concentrations were in the same range at both sites. Periphyton communities differed in biomass, but algal class composition and diatom diversity were similar. Community tolerance of P-communities was significantly enhanced for prometryn, but not for PNA and TBT, confirming site-specific effects on local periphyton for prometryn only. Thus, PICT enables in situ effect confirmation of phytotoxic compounds at the community level and seems to be suitable to support confirmation and enhance ecological realism of EDA.

  19. Effects of organic pollution on biological communities of marine biofilm on hard substrata.

    Science.gov (United States)

    Sanz-Lázaro, C; Fodelianakis, S; Guerrero-Meseguer, L; Marín, A; Karakassis, I

    2015-06-01

    We examined the effect of organic enrichment on diatom and bacterial assemblages of marine epilithic biofilms on two locations in the Mediterranean, one situated in Spain and the other in Greece. Total organic carbon, total organic nitrogen, stable isotopes (δ(13)C and δ(15)N) and chlorophyll a indicated significant incorporation of organic wastes, increased primary production and trophic niche modifications on the biofilms close to the organic enrichment source. In Spain, where the organic load was higher than in Greece, diatom and, to some extent, bacterial assemblages varied following the organic enrichment gradient. The taxonomic richness of diatom and bacterial communities was not influenced by organic enrichment. Classical community parameters showed consistent patterns to organic pollution in both locations, whereas community assemblages were only influenced when organic pollution was greatest. The successional patterns of these communities were similar to other epilithic communities. The modification of community assemblages induced by organic pollution may affect ecological functions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

    International Nuclear Information System (INIS)

    Coelho-Souza, Sergio A.; Guimaraes, Jean R.D.; Miranda, Marcio R.; Poirier, Hugo; Mauro, Jane B.N.; Lucotte, Marc; Mergler, Donna

    2011-01-01

    Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, δ 13 C, δ 15 N and bacterial heterotrophic production as 3 H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me 203 Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me 203 Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and δ 13 C. The discriminant analysis showed a significant difference in periphyton δ 15 N, δ 13 C and THg between seasons, where the rainy season presented higher δ 15 N and the wet period lighter δ 13 C, lower THg values and higher Me 203 Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: → During rainy season mercury (Hg 2+ ) is carried out from terrestrial to aquatic systems by runoff. → Macrophyte roots accumulates Hg 2+ from suspended particulate matter (SPM). → Hg methylation increases during the wet season. → Flooded forest is a source of labile organic carbon and bioavailable Hg. → Macrophytes decompose during the dry season and made up terrestrial soil.

  1. Incidence of invasive macrophytes on methylmercury budget in temperate lakes: Central role of bacterial periphytic communities

    International Nuclear Information System (INIS)

    Gentès, Sophie; Monperrus, Mathilde; Legeay, Alexia; Maury-Brachet, Régine; Davail, Stephane; André, Jean-Marc; Guyoneaud, Rémy

    2013-01-01

    Several studies demonstrated high mercury (Hg) methylation and demethylation in the periphyton associated with floating roots in tropical ecosystems. The importance of aquatic plants on methylmercury production in three temperate ecosystems from south-western France was evaluated through Hg species concentrations, and Hg methylation/demethylation activities by using stable isotopic tracers ( 199 Hg(II), Me 201 Hg). Hg accumulation and high methylation and demethylation yields were detected in plant roots and periphyton, whereas results for sediment and water were low to insignificant. The presence of sulfate reducing prokaryotes was detected in all compartments (T-RFLP based on dsrAB amplified through nested PCR) and their main role in Hg methylation could be demonstrated. In turn, sulfate reduction inhibition did not affect demethylation activities. The estimation of net MeHg budgets in these ecosystems suggested that aquatic rhizosphere is the principal location for methylmercury production and may represent an important source for the contamination of the aquatic food chain. - Highlights: ► Both Hg methylation and demethylation occur in the periphyton of temperate ecosystems. ► Aquatic rhizosphere is the main compartment for net methylmercury production. ► Sulfate reducers are detected in all ecosystem compartments (water, sediment, periphyton). ► Sulfate reducers are responsible for methylmercury production in aquatic roots. - The incidence of periphytic microbial communities on net methylmercury production is highlighted in temperate aquatic ecosystems.

  2. Community-Level Analysis of psbA Gene Sequences and Irgarol Tolerance in Marine Periphyton▿

    Science.gov (United States)

    Eriksson, K. M.; Clarke, A. K.; Franzen, L.-G.; Kuylenstierna, M.; Martinez, K.; Blanck, H.

    2009-01-01

    This study analyzes psbA gene sequences, predicted D1 protein sequences, species relative abundance, and pollution-induced community tolerance in marine periphyton communities exposed to the antifouling compound Irgarol 1051. The mechanism of action of Irgarol is the inhibition of photosynthetic electron transport at photosystem II by binding to the D1 protein. The metagenome of the communities was used to produce clone libraries containing fragments of the psbA gene encoding the D1 protein. Community tolerance was quantified with a short-term test for the inhibition of photosynthesis. The communities were established in a continuous flow of natural seawater through microcosms with or without added Irgarol. The selection pressure from Irgarol resulted in an altered species composition and an inducted community tolerance to Irgarol. Moreover, there was a very high diversity in the psbA gene sequences in the periphyton, and the composition of psbA and D1 fragments within the communities was dramatically altered by increased Irgarol exposure. Even though tolerance to this type of compound in land plants often depends on a single amino acid substitution (Ser264→Gly) in the D1 protein, this was not the case for marine periphyton species. Instead, the tolerance mechanism likely involves increased degradation of D1. When we compared sequences from low and high Irgarol exposure, differences in nonconserved amino acids were found only in the so-called PEST region of D1, which is involved in regulating its degradation. Our results suggest that environmental contamination with Irgarol has led to selection for high-turnover D1 proteins in marine periphyton communities at the west coast of Sweden. PMID:19088321

  3. Tissue N content and 15N natural abundance in epilithic mosses for indicating atmospheric N deposition in the Guiyang area, SW China

    International Nuclear Information System (INIS)

    Liu Xueyan; Xiao Huayun; Liu Congqiang; Li Youyi; Xiao Hongwei

    2008-01-01

    Tissue N contents and δ 15 N signatures in 175 epilithic mosses were investigated from urban to rural sites in Guiyang (SW China) to determine atmospheric N deposition. Moss N contents (0.85-2.97%) showed a significant decrease from the urban area (mean = 2.24 ± 0.32%, 0-5 km) to the rural area (mean = 1.27 ± 0.13%, 20-25 km), indicating that the level of N deposition decreased away from the urban environment, while slightly higher N contents re-occurred at sites beyond 30 km, suggesting higher N deposition in more remote rural areas. Moss δ 15 N ranged from -12.50 per mille to -1.39 per mille and showed a clear bimodal distribution (-12 per mille to -6 per mille and -5 per mille to -2 per mille ), suggesting that there are two main sources for N deposition in the Guiyang area. More negative δ 15 N (mean = -8.87 ± 1.65 per mille ) of urban mosses mainly indicated NH 3 released from excretory wastes and sewage, while the less negative δ 15 N (from -3.83 ± 0.82 per mille to -2.48 ± 0.95 per mille ) of rural mosses were mainly influenced by agricultural NH 3 . With more negative values in the urban area than in the rural area, the pattern of moss δ 15 N variation in Guiyang was found to be opposite to cities where N deposition is dominated by NO x -N. Therefore, NH x -N is the dominant N form deposited in the Guiyang area, which is supported by higher NH x -N than NO x -N in local atmospheric deposition. From the data showing that moss is responding to NH x -N/NO x -N in deposition it can be further demonstrated that the variation of moss δ 15 N from the Guiyang urban to rural area was more likely controlled by the ratio of urban-NH x /agriculture-NH x than the ratio of NH x -N/NO x -N. The results of this study have extended knowledge of atmospheric N sources in city areas, showing that urban sewage discharge could be important in cities co-generic to Guiyang

  4. Tissue N content and {sup 15}N natural abundance in epilithic mosses for indicating atmospheric N deposition in the Guiyang area, SW China

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xueyan [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: liuxueyan@vip.skleg.cn; Xiao Huayun [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)], E-mail: xiaohuayun@vip.skleg.cn; Liu Congqiang [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Li Youyi; Xiao Hongwei [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China)

    2008-09-15

    Tissue N contents and {delta}{sup 15}N signatures in 175 epilithic mosses were investigated from urban to rural sites in Guiyang (SW China) to determine atmospheric N deposition. Moss N contents (0.85-2.97%) showed a significant decrease from the urban area (mean = 2.24 {+-} 0.32%, 0-5 km) to the rural area (mean = 1.27 {+-} 0.13%, 20-25 km), indicating that the level of N deposition decreased away from the urban environment, while slightly higher N contents re-occurred at sites beyond 30 km, suggesting higher N deposition in more remote rural areas. Moss {delta}{sup 15}N ranged from -12.50 per mille to -1.39 per mille and showed a clear bimodal distribution (-12 per mille to -6 per mille and -5 per mille to -2 per mille ), suggesting that there are two main sources for N deposition in the Guiyang area. More negative {delta}{sup 15}N (mean = -8.87 {+-} 1.65 per mille ) of urban mosses mainly indicated NH{sub 3} released from excretory wastes and sewage, while the less negative {delta}{sup 15}N (from -3.83 {+-} 0.82 per mille to -2.48 {+-} 0.95 per mille ) of rural mosses were mainly influenced by agricultural NH{sub 3}. With more negative values in the urban area than in the rural area, the pattern of moss {delta}{sup 15}N variation in Guiyang was found to be opposite to cities where N deposition is dominated by NO{sub x}-N. Therefore, NH{sub x}-N is the dominant N form deposited in the Guiyang area, which is supported by higher NH{sub x}-N than NO{sub x}-N in local atmospheric deposition. From the data showing that moss is responding to NH{sub x}-N/NO{sub x}-N in deposition it can be further demonstrated that the variation of moss {delta}{sup 15}N from the Guiyang urban to rural area was more likely controlled by the ratio of urban-NH{sub x}/agriculture-NH{sub x} than the ratio of NH{sub x}-N/NO{sub x}-N. The results of this study have extended knowledge of atmospheric N sources in city areas, showing that urban sewage discharge could be important in cities co

  5. Community

    Science.gov (United States)

    stability Science & Innovation Collaboration Careers Community Environment Science & Innovation Recruitment Events Community Commitment Giving Campaigns, Drives Economic Development Employee Funded neighbor pledge: contribute to quality of life in Northern New Mexico through economic development

  6. Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

    Energy Technology Data Exchange (ETDEWEB)

    Coelho-Souza, Sergio A., E-mail: sacs@biof.ufrj.br [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Guimaraes, Jean R.D.; Miranda, Marcio R. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Poirier, Hugo [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mauro, Jane B.N. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Lucotte, Marc [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mergler, Donna [CINBIOSE, UQaM, CP 8888, succ. Centre-ville, Montreal, H3C 3P8 (Canada)

    2011-06-15

    Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, {delta}{sup 13}C, {delta}{sup 15}N and bacterial heterotrophic production as {sup 3}H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me{sup 203}Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me{sup 203}Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and {delta}{sup 13}C. The discriminant analysis showed a significant difference in periphyton {delta}{sup 15}N, {delta}{sup 13}C and THg between seasons, where the rainy season presented higher {delta}{sup 15}N and the wet period lighter {delta}{sup 13}C, lower THg values and higher Me{sup 203}Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: {yields} During rainy season mercury (Hg{sup 2+}) is carried out from terrestrial to aquatic systems by runoff. {yields} Macrophyte roots accumulates Hg{sup 2+} from suspended particulate matter (SPM). {yields} Hg methylation increases during the wet season. {yields} Flooded forest is a source of labile organic carbon and bioavailable Hg. {yields} Macrophytes

  7. Periphyton ecology of glacial and snowmelt streams, Ny-Alesund, Svalbard: presence of mineral particles in water and their erosive activity

    Czech Academy of Sciences Publication Activity Database

    Kubečková, Klára; Elster, Josef; Kanda, H.

    2001-01-01

    Roč. 123, - (2001), s. 141-172 ISSN 1438-9134. [International conference: Algae and extreme environments. Třeboň, 11.09.2000-16.09.2000] R&D Projects: GA AV ČR KSK6005114; GA AV ČR IAA6005002 Institutional research plan: CEZ:AV0Z6005908; CEZ:MSM 123100004 Keywords : Periphyton * species diversity and productivity * the Arctic * glacial snowmelt streams * physical disturbances erosive discharge * water turbidity Subject RIV: EA - Cell Biology Impact factor: 0.488, year: 2000

  8. Community.

    Science.gov (United States)

    Grauer, Kit, Ed.

    1995-01-01

    Art in context of community is the theme of this newsletter. The theme is introduced in an editorial "Community-Enlarging the Definition" (Kit Grauer). Related articles include: (1) "The Children's Bridge is not Destroyed: Heart in the Middle of the World" (Emil Robert Tanay); (2) "Making Bridges: The Sock Doll…

  9. Influence of a chlor-alkali superfund site on mercury bioaccumulation in periphyton and low-trophic level fauna

    Science.gov (United States)

    Buckman, Kate L.; Marvin-DiPasquale, Mark C.; Taylor, Vivien F.; Chalmers, Ann T.; Broadley, Hannah J.; Agee, Jennifer L.; Jackson, Brian P.; Chen, Celia Y.

    2015-01-01

    In Berlin, New Hampshire, USA, the Androscoggin River flows adjacent to a former chlor-alkali facility that is a US Environmental Protection Agency Superfund site and source of mercury (Hg) to the river. The present study was conducted to determine the fate and bioaccumulation of methylmercury (MeHg) to lower trophic-level taxa in the river. Surface sediment directly adjacent to the source showed significantly elevated MeHg (10–40× increase, mean ± standard deviation [SD]: 20.1 ± 24.8 ng g–1 dry wt) and total mercury (THg; 10–30× increase, mean ± SD: 2045 ± 2669 ng g–1 dry wt) compared with all other reaches, with sediment THg and MeHg from downstream reaches elevated (3–7× on average) relative to the reference (THg mean ± SD: 33.5 ± 9.33 ng g–1 dry wt; MeHg mean ± SD: 0.52 ± 0.21 ng g–1 dry wt). Water column THg concentrations adjacent to the point source for both particulate (0.23 ng L–1) and dissolved (0.76 ng L–1) fractions were 5-fold higher than at the reference sites, and 2-fold to 5-fold higher than downstream. Methylmercury production potential of periphyton material was highest (2–9 ng g–1 d–1 dry wt) adjacent to the Superfund site; other reaches were close to or below reporting limits (0. 1 ng g–1 d–1 dry wt). Total Hg and MeHg bioaccumulation in fauna was variable across sites and taxa, with no clear spatial patterns downstream of the contamination source. Crayfish, mayflies, and shiners showed a weak positive relationship with porewater MeHg concentration.

  10. Effects of carbohydrate source for maintaining a high C:N ratio and fish driven re-suspension on pond ecology and production in periphyton-based freshwater prawn culture systems

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Adhikary, R.K.; Rahman, S.M.S.; Azim, M.E.; Verreth, J.A.J.

    2010-01-01

    The present research investigated the effect of carbohydrate (CH) source for maintaining a high C:N ratio, and tilapia driven bioturbation on pond ecology, production and economical performances in C/N controlled periphyton-based (C/N-CP) freshwater prawn ponds. Two carbohydrate sources (high-cost

  11. Effects of cadmium stress and sorption kinetics on tropical freshwater periphytic communities in indoor mesocosm experiments

    International Nuclear Information System (INIS)

    Bere, Taurai; Tundisi, José Galizia

    2012-01-01

    Understanding the cause and effect relationship between stressors and biota is crucial for the effective management, restoration and preservation of aquatic systems. The objective of the present study was to assess the effects of five Cd concentrations on tropical periphyton community growth, Cd accumulation kinetics, as well as the effects of Cd on diatom community structure and composition. Natural periphyton communities were transferred to artificial stream chambers and exposed to Cd concentrations of 0.005, 0.01, 0.03, 0.05 and 0.1 mg.L −1 . Metal accumulation (total and intracellular) in biofilms, dry weight and ash-free dry mass, growth rate, algal cell density and diatom community composition were analysed on samples collected after 1, 2 and 4 weeks of colonization. Periphyton growth and development were significantly lowered by Cd concentrations > 0.03 mg.L −1 . High Cd accumulation capacity by periphyton was demonstrated with total and intracellular Cd content in biofilms reflecting the effects of concentrations of Cd in the culture media and exposure duration. Total and intracellular Cd content generally increased in treatments in the order 0.005 −1 at any sampling time with increasing level of accumulated Cd with duration of exposure in all the systems. Shifts in species composition (development of more resistant species like Achnanthidium minutissimum and reduction of sensitive ones like Diatoma vulgare, Navicula viridula and Navicula cryptocephala), decreases in species richness and diversity and morphological alterations (deformities) of diatom cells with increasing Cd concentration and exposure duration were observed. The results give valuable information on Cd impact of freshwater biofilms. -- Highlights: ► We investigated toxicity and sorption kinetics of Cd on periphyton communities. ► [Cd] > 0.03 mg.L −1 lowers growth. ► Absorbed Cd was a function of duration of exposure and [Cd]. ► Changes in community composition were recorded

  12. Effects of cadmium stress and sorption kinetics on tropical freshwater periphytic communities in indoor mesocosm experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bere, Taurai, E-mail: taubere@yahoo.com [Instituto Internacional de Ecologia, Rua Bento Carlos, 750, Centro, Sao Carlos, Sao Paulo (Brazil); Universidade Federal De Sao Carlosm, Programa de Pos-Graduacao em Ecologia e Recursos Naturais, Rodovia Washington Luis, km 235, SP-310, Sao Carlos, Sao Paulo (Brazil); Tundisi, Jose Galizia [Instituto Internacional de Ecologia, Rua Bento Carlos, 750, Centro, Sao Carlos, Sao Paulo (Brazil)

    2012-08-15

    Understanding the cause and effect relationship between stressors and biota is crucial for the effective management, restoration and preservation of aquatic systems. The objective of the present study was to assess the effects of five Cd concentrations on tropical periphyton community growth, Cd accumulation kinetics, as well as the effects of Cd on diatom community structure and composition. Natural periphyton communities were transferred to artificial stream chambers and exposed to Cd concentrations of 0.005, 0.01, 0.03, 0.05 and 0.1 mg.L{sup -1}. Metal accumulation (total and intracellular) in biofilms, dry weight and ash-free dry mass, growth rate, algal cell density and diatom community composition were analysed on samples collected after 1, 2 and 4 weeks of colonization. Periphyton growth and development were significantly lowered by Cd concentrations > 0.03 mg.L{sup -1}. High Cd accumulation capacity by periphyton was demonstrated with total and intracellular Cd content in biofilms reflecting the effects of concentrations of Cd in the culture media and exposure duration. Total and intracellular Cd content generally increased in treatments in the order 0.005 < 0.01 < 0.03 < 0.05 < 0.1 mg.L{sup -1} at any sampling time with increasing level of accumulated Cd with duration of exposure in all the systems. Shifts in species composition (development of more resistant species like Achnanthidium minutissimum and reduction of sensitive ones like Diatoma vulgare, Navicula viridula and Navicula cryptocephala), decreases in species richness and diversity and morphological alterations (deformities) of diatom cells with increasing Cd concentration and exposure duration were observed. The results give valuable information on Cd impact of freshwater biofilms. -- Highlights: Black-Right-Pointing-Pointer We investigated toxicity and sorption kinetics of Cd on periphyton communities. Black-Right-Pointing-Pointer [Cd] > 0.03 mg.L{sup -1} lowers growth. Black

  13. A mine of information: Benthic algal communities as biomonitors of metal contamination from abandoned tailings

    International Nuclear Information System (INIS)

    Lavoie, Isabelle; Lavoie, Michel; Fortin, Claude

    2012-01-01

    Various biomonitoring approaches were tested in the field to assess the response of natural periphythic algal communities to chronic metal contamination downstream from an abandoned mine tailings site. The accumulation of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) as well as the production of phytochelatins, the presence of diatom taxa known to tolerate high metal concentrations, diatom diversity and the presence of teratologies were determined. We observed highly significant relationships between intracellular metal and calculated free metal ion concentrations. Such relationships are often observed in laboratory studies but have been rarely validated in field studies. These results suggest that the concentration of metal inside the field-collected periphyton, regardless of its species composition, is a good indicator of exposure and is an interesting proxy for bioavailable metal concentrations in natural waters. The presence of teratologies and metal-tolerant taxa at our contaminated sites provided a clear indication that diatom communities were responding to this metal stress. A multi-metric approach integrating various bioassessment methods could be used for the field monitoring of metal contamination and the quantification of its effects. Highlights: ► Various approaches for metal contamination biomonitoring were used in the field. ► Metal accumulation in periphyton is correlated to free ion concentration. ► Teratologies and metal-tolerant taxa provided a clear indication of metal stress. ► Stream periphyton shows great potential as a biomonitor of metal contamination.

  14. Impacts of agricultural irrigation on nearby freshwater ecosystems: the seasonal influence of triazine herbicides in benthic algal communities.

    Science.gov (United States)

    Lorente, Carmen; Causapé, Jesús; Glud, Ronnie N; Hancke, Kasper; Merchán, Daniel; Muñiz, Selene; Val, Jonatan; Navarro, Enrique

    2015-01-15

    A small hydrological basin (Lerma, NE Spain), transformed from its natural state (steppe) to rain-fed agriculture and recently to irrigation agriculture, has been monitored across four seasons of an agricultural year. The goal of this study was to assess how and whether agricultural activities impacted the nearby freshwater ecosystems via runoff. Specifically, we assessed the toxicity of three triazine herbicides, terbuthylazine, atrazine and simazine on the photosynthetic efficiency and structure of algal benthic biofilms (i.e., phototropic periphyton) in the small creek draining the basin. It was expected that the seasonal runoff of the herbicides in the creek affected the sensitivity of the periphyton in accord with the rationale of the Pollution Induced Community Tolerance (PICT): the exposure of the community to pollutants result in the replacement of sensitive species by more tolerant ones. In this way, PICT can serve to establish causal linkages between pollutants and the observed biological impacts. The periphyton presented significantly different sensitivities against terbuthylazine through the year in accord with the seasonal application of this herbicide in the crops nowadays. The sensitivity of already banned herbicides, atrazine and simazine does not display a clear seasonality. The different sensitivities to herbicides were in agreement with the expected exposures scenarios, according to the agricultural calendar, but not with the concentrations measured in water, which altogether indicates that the use of PICT approach may serve for long-term monitoring purposes. That will provide not only causal links between the occurrence of chemicals and their impacts on natural communities, but also information about the occurrence of chemicals that may escape from traditional sampling methods (water analysis). In addition, the EC50 and EC10 of periphyton for terbuthylazine or simazine are the first to be published and can be used for impact assessments

  15. Community-level microalgal toxicity assessment by multiwavelength-excitation PAM fluorometry

    International Nuclear Information System (INIS)

    Schmitt-Jansen, Mechthild; Altenburger, Rolf

    2008-01-01

    In ecotoxicological studies involving community-level investigations, rapid and multiparametric fluorescence-based methods may provide substantial advantages over traditional methods used for structural and functional community analysis. Therefore, multiwavelength-excitation pulse-amplitude modulated (PAM) fluorometry was applied in this study to assess long-term changes in periphyton community structure, short-term effects on periphyton functioning (photosynthesis) and pollution induced community tolerance (PICT). For inter-calibration, periphyton structure was evaluated by chemotaxonomic analysis of accessory pigments and a four-wavelength-excitation PAM fluorometer. Short-term effects of herbicides were evaluated by fluorescence quenching analysis and 14 C-incorporation as a proxy of primary production. Subsequently, the method was applied to assess structural and functional changes in periphyton communities after isoproturon exposure for 14 and 26 days, respectively. Results showed good correlation of the PAM fluorescence-based measurements with traditional methods for biofilms in the initial colonisation phase for structural and functional parameters. However, for biofilms older than 9 weeks PAM fluorescence may underestimate biomass. Multiwavelength-excitation PAM fluorometry showed good correlation with marker pigment concentrations indicating that this method provides a reliable estimate of the community structure. PAM fluorometry was able to quantify changes of biomass and follow relative shifts in class composition of biofilms under exposure of isoproturon. Short-term tests based on the quantification of the inhibition of the effective quantum yield revealed a concentration-dependent increase of PICT. The observation of two succession phases of the biofilms after 14 and 26 days of growth, respectively, revealed that sensitivity of biofilms decreased with increasing age and biomass, respectively, but PICT remained a characteristic parameter of exposed

  16. Community-level microalgal toxicity assessment by multiwavelength-excitation PAM fluorometry

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt-Jansen, Mechthild [UFZ-Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig (Germany)], E-mail: Mechthild.Schmitt@ufz.de; Altenburger, Rolf [UFZ-Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig (Germany)

    2008-01-20

    In ecotoxicological studies involving community-level investigations, rapid and multiparametric fluorescence-based methods may provide substantial advantages over traditional methods used for structural and functional community analysis. Therefore, multiwavelength-excitation pulse-amplitude modulated (PAM) fluorometry was applied in this study to assess long-term changes in periphyton community structure, short-term effects on periphyton functioning (photosynthesis) and pollution induced community tolerance (PICT). For inter-calibration, periphyton structure was evaluated by chemotaxonomic analysis of accessory pigments and a four-wavelength-excitation PAM fluorometer. Short-term effects of herbicides were evaluated by fluorescence quenching analysis and {sup 14}C-incorporation as a proxy of primary production. Subsequently, the method was applied to assess structural and functional changes in periphyton communities after isoproturon exposure for 14 and 26 days, respectively. Results showed good correlation of the PAM fluorescence-based measurements with traditional methods for biofilms in the initial colonisation phase for structural and functional parameters. However, for biofilms older than 9 weeks PAM fluorescence may underestimate biomass. Multiwavelength-excitation PAM fluorometry showed good correlation with marker pigment concentrations indicating that this method provides a reliable estimate of the community structure. PAM fluorometry was able to quantify changes of biomass and follow relative shifts in class composition of biofilms under exposure of isoproturon. Short-term tests based on the quantification of the inhibition of the effective quantum yield revealed a concentration-dependent increase of PICT. The observation of two succession phases of the biofilms after 14 and 26 days of growth, respectively, revealed that sensitivity of biofilms decreased with increasing age and biomass, respectively, but PICT remained a characteristic parameter of exposed

  17. 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.

  18. Characterization of habitats based on algal periphyton biomass in the upper Paraná River floodplain, Brazil Mudanças na biomassa de algas perifíticas na planície de inundação do alto Rio Paraná, Brasil

    Directory of Open Access Journals (Sweden)

    JA. Leandrini

    2008-08-01

    Full Text Available Considering the relevant role played by the hydrological regime on the structure and functioning of floodplains, this study aims at characterizing different types of aquatic environments according to periphyton biomass and evaluating the influence of the fluviometric levels of the Paraná River and other forcing functions upon the periphytic community. Periphyton (chlorophyll a was analyzed in 28 habitats, during the years 2000 and 2001, in high and low water seasons. Both years were characterized by lacking the characteristic high water season. The Principal Components Analysis revealed two groups. The first component was positively associated with hydrometric level, electric conductivity, pH and transparency, and negatively with total nitrogen and total phosphorus, dissolved organic carbon and turbidity. The second component separated the habitats of Paraná River in the period of low waters from other environments, mainly for hydrometric level and high transparency values. Periphytic biomass of the habitats demonstrated that the maintenance of the functional integrity of the Upper Paraná River floodplain is closely related to its hydrologic cycle.Tendo como princípio que o regime hidrológico é a principal função de força em planícies de inundação, este trabalho visa caracterizar diferentes ambientes através da biomassa da comunidade perifítica e relacionar a influência do nível hidrométrico sobre esta comunidade. Para isso, a biomassa perifítica (clorofila a foi analisada em 28 habitats, sendo amostrados dois anos, 2000 e 2001, em diferentes períodos, águas altas e águas baixas. Na Análise de Componentes Principais, foram evidenciados dois grupos. O primeiro componente associado positivamente com o nível hidrométrico, condutividade elétrica, pH e transparência e, negativamente, com nitrogênio e fósforo total, carbono orgânico dissolvido e turbidez. O segundo componente separou os ambientes pertencentes ao rio Paran

  19. Combined effects of road salt and an insecticide on wetland communities.

    Science.gov (United States)

    Stoler, Aaron B; Walker, Brent M; Hintz, William D; Jones, Devin K; Lind, Lovisa; Mattes, Brian M; Schuler, Matthew S; Relyea, Rick A

    2017-03-01

    As the numbers of chemical contaminants in freshwater ecosystems increase, it is important to understand whether contaminants interact in ecologically important ways. The present study investigated the independent and interactive effects of 2 contaminants that frequently co-occur in freshwater environments among higher latitudes, including a commonly applied insecticide (carbaryl) and road salt (NaCl). The hypothesis was that the addition of either contaminant would result in a decline in zooplankton, an algal bloom, and the subsequent decline of both periphyton and periphyton consumers. Another hypothesis was that combining the contaminants would result in synergistic effects on community responses. Outdoor mesocosms were used with communities that included phytoplankton, periphyton, zooplankton, amphipods, clams, snails, and tadpoles. Communities were exposed to 4 environmentally relevant concentrations of salt (27 mg Cl - L -1 , 77 mg Cl - L -1 , 277 mg Cl - L -1 , and 727 mg Cl - L -1 ) fully crossed with 4 carbaryl treatments (ethanol, 0 µg L -1 , 5 µg L -1 , and 50 µg L -1 ) over 57 d. Contaminants induced declines in rotifer and cladoceran zooplankton, but only carbaryl induced an algal bloom. Consumers exhibited both positive and negative responses to contaminants, which were likely the result of both indirect community interactions and direct toxicity. In contrast to the hypothesis, no synergistic effects were found, although copepod densities declined when high concentrations of both chemicals were combined. The results suggest that low concentrations of salt and carbaryl are likely to have mostly independent effects on aquatic communities. Environ Toxicol Chem 2017;36:771-779. © 2016 SETAC. © 2016 SETAC.

  20. [Changes in phytoperiphyton community during seasonal succession: influence of plankton sedimentation and grazing by phytophages--Chironomid larvae].

    Science.gov (United States)

    Lukin, V B

    2002-01-01

    The investigation of seasonal changes in spatial structure of phytoperiphyton during succession was conducted at the lower reaches of Akulovsky water channel from April to August 2000. At the beginning of succession from April to June dominant forms were chain-forming diatoms and filamentous green algae, sedimented from plankton. Later, at the middle of June under increasing pressure of herbivorous, they were replaced by stretched unicellular diatoms and colonial cyanobacteria. In late June-August, when herbivorous predation was the most intensive, the relative abundance of typical periphytonic forms decreased while that of settled planktonic forms increased. The effect of planktonic algae sedimentation on periphyton composition was evaluated as similarity between phytoperiphyton and phytoplankton communities measured with Chekanovski--Sorensen index. The value of this index tends to decrease with the development of periphyton while showing some relation to intensity of herbivorous pressure. Minimal values of Chekanovski--Sorensen index were under moderate herbivorous density, whereas maximal values were observed in periods of extremely high or low herbivorous density.

  1. The use of indices for evaluating the periphytic community in two kinds of substrate in Imboassica Lagoon, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Fernandes V. O.

    2003-01-01

    Full Text Available Biological indices based on the biomass (dry weight, ash content, and chlorophyll-a of the periphyton in a natural (submersed leaves of Typha domingensis Pers and in an artificial (plastic hoses substrate were compared, in experiments performed in summer and winter, in two sampling stations of Imboassica Lagoon, Macaé, Rio de Janeiro. The periphytic community exhibited low biomass at the beginning and end of the experiments, and moderate biomass in the intermediate period of the experiment, whatever the kind of substrate, sampling station, and season. In both seasons, there was a spatial variation regarding the degree of trophy of the periphyton, due to the difference of nutrient availability among the sampling stations. The alternation of inorganic and organic periphyton, as well as of their heterotrophic, hetero-autotrophic, auto-heterotrophic and, autotrophic character was due to changes in the abiotic factors of the sampling periods. The Lakatos index proved more sensitive than the Autotrophic Index to variations in the composition of the periphytic community.

  2. Non-destructive sampling of rock-dwelling microbial communities using sterile adhesive tape.

    Science.gov (United States)

    Cutler, Nick A; Oliver, Anna E; Viles, Heather A; Whiteley, Andrew S

    2012-12-01

    Building stone provides a habitat for an array of microorganisms, many of which have been demonstrated to have a deleterious effect on the appearance and/or structural integrity of stone masonry. It is essential to understand the composition and structure of stone-dwelling (lithobiontic) microbial communities if successful stone conservation strategies are to be applied, particularly in the face of global environmental change. Ideally, the techniques used to sample such assemblages should be non-destructive due to the sensitive conservation status of many stone buildings. This paper quantitatively assesses the performance of sterile adhesive tape as a non-destructive sampling technique and compares the results of tape sampling with an alternative, destructive, sampling method. We used DNA fingerprinting (TRFLP) to characterise the algal, fungal and bacterial communities living on a stone slab. Our results demonstrate that tape sampling may be used to collect viable quantities of microbial DNA from environmental samples. This technique is ideally suited to the sampling of microbial biofilms, particularly when these communities are dominated by green algae. It provides a good approximation of total community diversity (i.e. the aggregate diversity of epilithic and endolithic communities). Tape sampling is straightforward, rapid and cost effective. When combined with molecular analytical techniques, this sampling method has the potential to make a major contribution to efforts to understand the structure of lithobiontic microbial communities and our ability to predict the response of such communities to future environmental change. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Temporal changes in periphytic meiofauna in lakes of different trophic states

    Directory of Open Access Journals (Sweden)

    Kurt Pettersson

    2012-01-01

    Full Text Available Meiofaunal organisms in the periphyton of stony hard-substrates (epilithon were studied in three Swedish lakes with different trophic states (oligo-, meso- and eutrophic with respect to seasonal successions in abundance, biomass, and production. Over a period of 2 years, the meiofaunal population of all three lakes fluctuated greatly, with densities varying up to nine-fold within a season. In the oligotrophic lake, a significant decrease in meiofauna in winter was striking, whereas in the other two lakes, richer in nutrients, there was a pronounced peak in early summer. Although the lakes, on average, did not differ in epilithic organic and inorganic material, the differences in meiofaunal abundance, biomass, and production were significant. Correlation analysis revealed that altogether the meiofaunal biomass was positively related to the lakes’ trophic state (total phosphorus, while the meiofaunal abundance and production along the trophic spectrum displayed a humped-shape distribution, with maximum values measured in the mesotrophic Lake Erken (1324 ind cm-2 and 2249 mg DW cm-2 y-1. Nematodes were the dominant meiofaunal group in the epilithon of all three lakes, accounting for up to 58% in abundance, 33% in biomass and 55% in production of the whole meiofaunal community. However, their relative importance tended to decrease with increasing trophic state. Beside nematodes, rotifers, oligochaetes, copepods and tardigrades were also found in large numbers in the epilithon. Overall, the results demonstrated that, due to their high abundance, biomass, and production, meiofaunal organisms play an important role in epilithic communities.

  4. Long-term hydrologic effects on marsh plant community structure in the southern Everglades

    Science.gov (United States)

    Busch, David E.; Loftus, W.F.; Bass, O.L.

    1998-01-01

    Although large-scale transformation of Everglades landscapes has occurred during the past century, the patterns of association among hydrologic factors and southern Everglades freshwater marsh vegetation have not been well-defined. We used a 10-year data base on the aquatic biota of Shark Slough to classify vegetation and describe plant community change in intermediate- to long-hydroperiod Everglades marshes. Study area marsh vegetation was quantitatively grouped into associations dominated by 1) Cladium jamaicense, 2) a group of emergents including Eleocharis cellulosa, Sagittaria lancifolia, and Rhyncospora tracyi, 3) taxa associated with algal mats (Utricularia spp. and Bacopa caroliniana), and 4) the grasses Panicum hemitomon and Paspalidium geminatum. During the decade evaluated, the range of water depths that characterized our study sites approached both extremes depicted in the 40-year hydrologic record for the region. Water depths were near the long-term average during the mid-1980s, declined sharply during a late 1980s drought, and underwent a prolonged increase from 1991 through 1995. Overall macrophyte cover varied inversely with water depth, while the response of periphyton was more complex. An ordination analysis, based on plant species abundance, revealed that study area vegetation structure was associated with hydrologic patterns. Marsh plant community structure showed evidence of cyclic interannual variation corresponding to hydrologic change over the decade evaluated. Lower water depths, the occurrence of marl substrates, and high periphyton cover were correlated. These factors contributed to reduced macrophyte cover in portions of the study area from which water had been diverted.

  5. Ecological and evolutionary effects of stickleback on community structure.

    Directory of Open Access Journals (Sweden)

    Simone Des Roches

    Full Text Available Species' ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus. We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density and evolutionary (phenotypic diversity and specialization factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities.

  6. Volunteer stream monitoring: Do the data quality and monitoring experience support increased community involvement in freshwater decision making?

    Directory of Open Access Journals (Sweden)

    Richard G. Storey

    2016-12-01

    Full Text Available Recent freshwater policy reforms in New Zealand promote increased community involvement in freshwater decision making and management. Involving community members in scientific monitoring increases both their knowledge and their ability to discuss this knowledge with professionals, potentially increasing their influence in decision-making processes. However, these interactions rarely occur because, in particular, of perceptions that volunteer-collected data are unreliable. We assessed the agreement between volunteer (community group and local government (regional council data at nine stream sites across New Zealand. Over 18 months, community groups and regional council staff monitored, in parallel, a common set of water quality variables, physical habitat, periphyton and benthic macroinvertebrates that are routinely used by regional councils for statutory state of environment reporting. Community groups achieved close agreement (correlations ≥ 0.89, bias < 1% with regional councils for temperature, electrical conductivity, visual water clarity, and Escherichia coli. For dissolved oxygen, nitrate, and pH, correlations were weaker (0.2, 0.53, and 0.4, respectively. Volunteer assessments of physical habitat were as consistent over time as those of councils. For visual assessments of thick periphyton growths (% streambed cover, volunteers achieved a correlation of 0.93 and bias of 0.1% relative to councils. And for a macroinvertebrate biotic index that indicates water and habitat quality, correlation was 0.88, bias was < 5%, and the average difference was 12% of the index score. Volunteers showed increased awareness of local freshwaters, understanding of stream ecosystems, and attentiveness to local and national freshwater issues. Most volunteers had shared their knowledge and interest with others in their community. Most groups had developed relationships with their regional council, and some volunteers became more interested in engaging in

  7. Influence of global change-related impacts on the mercury toxicity of freshwater algal communities.

    Science.gov (United States)

    Val, Jonatan; Muñiz, Selene; Gomà, Joan; Navarro, Enrique

    2016-01-01

    The climatic-change related increase of temperatures, are expected to alter the distribution and survival of freshwater species, ecosystem functions, and also the effects of toxicants to aquatic biota. This study has thus assessed, as a first time, the modulating effect of climate-change drivers on the mercury (Hg) toxicity of freshwater algal photosynthesis. Natural benthic algal communities (periphyton) have been exposed to Hg under present and future temperature scenarios (rise of 5 °C). The modulating effect of other factors (also altered by global change), as the quality and amount of suspended and dissolved materials in the rivers, has been also assessed, exposing algae to Hg in natural river water or a synthetic medium. The EC50 values ranged from the 0.15-0.74 ppm for the most sensitive communities, to the 24-40 ppm for the most tolerant. The higher tolerance shown by communities exposed to higher Hg concentrations, as Jabarrella was in agreement with the Pollution Induced Community Tolerance concept. In other cases, the dominance of the invasive diatom Didymosphenia geminata explained the tolerance or sensitivity of the community to the Hg toxicity. Results shown that while increases in the suspended solids reduced Hg bioavailability, changes in the dissolved materials - such as organic carbon - may increase it and thus its toxic effects on biota. The impacts of the increase of temperatures on the toxicological behaviour of periphyton (combining both changes at species composition and physiological acclimation) would be certainly modulated by other effects at the land level (i.e., alterations in the amount and quality of dissolved and particulate substances arriving to the rivers). Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Salinization triggers a trophic cascade in experimental freshwater communities with varying food-chain length.

    Science.gov (United States)

    Hintz, William D; Mattes, Brian M; Schuler, Matthew S; Jones, Devin K; Stoler, Aaron B; Lind, Lovisa; Relyea, Rick A

    2017-04-01

    The application of road deicing salts in northern regions worldwide is changing the chemical environment of freshwater ecosystems. Chloride levels in many lakes, streams, and wetlands exceed the chronic and acute thresholds established by the United States and Canada for the protection of freshwater biota. Few studies have identified the impacts of deicing salts in stream and wetland communities and none have examined impacts in lake communities. We tested how relevant concentrations of road salt (15, 100, 250, 500, and 1000 mg Cl - /L) interacted with experimental communities containing two or three trophic levels (i.e., no fish vs. predatory fish). We hypothesized that road salt and fish would have a negative synergistic effect on zooplankton, which would then induce a trophic cascade. We tested this hypothesis in outdoor mesocosms containing filamentous algae, periphyton, phytoplankton, zooplankton, several macroinvertebrate species, and fish. We found that the presence of fish and high salt had a negative synergistic effect on the zooplankton community, which in turn caused an increase in phytoplankton. Contributing to the magnitude of this trophic cascade was a direct positive effect of high salinity on phytoplankton abundance. Cascading effects were limited with respect to impacts on the benthic food web. Periphyton and snail grazers were unaffected by the salt-induced trophic cascade, but the biomass of filamentous algae decreased as a result of competition with phytoplankton for light or nutrients. We also found direct negative effects of high salinity on the biomass of filamentous algae and amphipods (Hyalella azteca) and the mortality of banded mystery snails (Viviparus georgianus) and fingernail clams (Sphaerium simile). Clam mortality was dependent on the presence of fish, suggesting a non-consumptive interactive effect with salt. Our results indicate that globally increasing concentrations of road salt can alter community structure via both direct

  9. Submerged Macrophytes Mitigate Direct and Indirect Insecticide Effects in Freshwater Communities

    Science.gov (United States)

    Brogan, William R.; Relyea, Rick A.

    2015-01-01

    Understanding how ecological interactions mitigate the impacts of perturbations such as pesticides in biological communities is an important basic and applied question for ecologists. In aquatic ecosystems, new evidence from microcosm experiments suggests that submerged macrophytes can buffer cladocerans from pulse exposures to the widely used insecticide malathion, and that mitigation increases with macrophyte density. However, whether these results scale up to more complex aquatic communities where ecological interactions such as competition can alter toxicity is unknown. Further, macrophyte abilities to mitigate different insecticide exposure scenarios (i.e. single versus repeated pulses) have never been tested. To address these gaps, we performed a factorial mesocosm experiment examining the influence of four macrophyte treatments (0, 10, 50, or 100 Elodea Canadensis shoots planted per mesocosm) crossed with three malathion exposure scenarios (no insecticide, single pulse, repeated pulses) on aquatic communities containing zooplankton, phytoplankton, periphyton, two snail species, and larval amphibians. In the absence of macrophytes, single malathion pulses caused short-term declines in cladoceran abundance followed by their rapid recovery, which precluded any indirect effects (i.e. trophic cascades). However, repeated malathion pulses caused cladoceran extinctions, resulting in persistent phytoplankton blooms and reduced abundance of one snail species. In contrast, with macrophytes present, even at low density, malathion had no effect on any taxa. We also discovered novel effects of macrophytes on the benthic food web. In the two highest macrophyte treatments, we observed trends of reduced periphyton biomass, decreased abundance of one snail species, and decreased amphibian time to and mass at metamorphosis. To our knowledge, this is the first evidence of negative submerged macrophyte effects on amphibians, a taxa of global conservation concern. Our findings

  10. Submerged macrophytes mitigate direct and indirect insecticide effects in freshwater communities.

    Directory of Open Access Journals (Sweden)

    William R Brogan

    Full Text Available Understanding how ecological interactions mitigate the impacts of perturbations such as pesticides in biological communities is an important basic and applied question for ecologists. In aquatic ecosystems, new evidence from microcosm experiments suggests that submerged macrophytes can buffer cladocerans from pulse exposures to the widely used insecticide malathion, and that mitigation increases with macrophyte density. However, whether these results scale up to more complex aquatic communities where ecological interactions such as competition can alter toxicity is unknown. Further, macrophyte abilities to mitigate different insecticide exposure scenarios (i.e. single versus repeated pulses have never been tested. To address these gaps, we performed a factorial mesocosm experiment examining the influence of four macrophyte treatments (0, 10, 50, or 100 Elodea Canadensis shoots planted per mesocosm crossed with three malathion exposure scenarios (no insecticide, single pulse, repeated pulses on aquatic communities containing zooplankton, phytoplankton, periphyton, two snail species, and larval amphibians. In the absence of macrophytes, single malathion pulses caused short-term declines in cladoceran abundance followed by their rapid recovery, which precluded any indirect effects (i.e. trophic cascades. However, repeated malathion pulses caused cladoceran extinctions, resulting in persistent phytoplankton blooms and reduced abundance of one snail species. In contrast, with macrophytes present, even at low density, malathion had no effect on any taxa. We also discovered novel effects of macrophytes on the benthic food web. In the two highest macrophyte treatments, we observed trends of reduced periphyton biomass, decreased abundance of one snail species, and decreased amphibian time to and mass at metamorphosis. To our knowledge, this is the first evidence of negative submerged macrophyte effects on amphibians, a taxa of global conservation concern

  11. Submerged macrophytes mitigate direct and indirect insecticide effects in freshwater communities.

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2015-01-01

    Understanding how ecological interactions mitigate the impacts of perturbations such as pesticides in biological communities is an important basic and applied question for ecologists. In aquatic ecosystems, new evidence from microcosm experiments suggests that submerged macrophytes can buffer cladocerans from pulse exposures to the widely used insecticide malathion, and that mitigation increases with macrophyte density. However, whether these results scale up to more complex aquatic communities where ecological interactions such as competition can alter toxicity is unknown. Further, macrophyte abilities to mitigate different insecticide exposure scenarios (i.e. single versus repeated pulses) have never been tested. To address these gaps, we performed a factorial mesocosm experiment examining the influence of four macrophyte treatments (0, 10, 50, or 100 Elodea Canadensis shoots planted per mesocosm) crossed with three malathion exposure scenarios (no insecticide, single pulse, repeated pulses) on aquatic communities containing zooplankton, phytoplankton, periphyton, two snail species, and larval amphibians. In the absence of macrophytes, single malathion pulses caused short-term declines in cladoceran abundance followed by their rapid recovery, which precluded any indirect effects (i.e. trophic cascades). However, repeated malathion pulses caused cladoceran extinctions, resulting in persistent phytoplankton blooms and reduced abundance of one snail species. In contrast, with macrophytes present, even at low density, malathion had no effect on any taxa. We also discovered novel effects of macrophytes on the benthic food web. In the two highest macrophyte treatments, we observed trends of reduced periphyton biomass, decreased abundance of one snail species, and decreased amphibian time to and mass at metamorphosis. To our knowledge, this is the first evidence of negative submerged macrophyte effects on amphibians, a taxa of global conservation concern. Our findings

  12. Effects of the pyrethroid insecticide cypermethrin on a freshwater community studied under field conditions. II. Direct and indirect effects on the species composition

    DEFF Research Database (Denmark)

    Wendt-Rasch, Lina; Friberg-Jensen, Ursula; Woin, Per

    2003-01-01

    species were calculated using inverse regression and revealed that copepod nauplii were the most sensitive (NEC=0.01 microg/l) of the crustacean groups examined. The observed alterations of the species composition of the autotrophic communities as well as of the rotifers were most likely caused indirectly...... cypermethrin concentrations, ranging from 0.01 to 6 microg/l. This paper is the second in a series of two and describes the effects on the species composition of the crustacean, rotifer, periphyton and phytoplankton communities. Multivariate ordination technique (redundancy analysis (RDA) combined with Monte...... Carlo permutation tests) showed that exposure to cypermethrin caused significant changes in the species composition of the communities. Changes in the structure of the communities were observed following exposure to a nominal concentration of 0.13 microg cypermethrin per litre above. The direct acute...

  13. Protocols for collection of streamflow, water-quality, streambed-sediment, periphyton, macroinvertebrate, fish, and habitat data to describe stream quality for the Hydrobiological Monitoring Program, Equus Beds Aquifer Storage and Recovery Program, city of Wichita, Kansas

    Science.gov (United States)

    Stone, Mandy L.; Rasmussen, Teresa J.; Bennett, Trudy J.; Poulton, Barry C.; Ziegler, Andrew C.

    2012-01-01

    The city of Wichita, Kansas uses the Equus Beds aquifer, one of two sources, for municipal water supply. To meet future water needs, plans for artificial recharge of the aquifer have been implemented in several phases. Phase I of the Equus Beds Aquifer Storage and Recovery (ASR) Program began with injection of water from the Little Arkansas River into the aquifer for storage and subsequent recovery in 2006. Construction of a river intake structure and surface-water treatment plant began as implementation of Phase II of the Equus Beds ASR Program in 2010. An important aspect of the ASR Program is the monitoring of water quality and the effects of recharge activities on stream conditions. Physical, chemical, and biological data provide the basis for an integrated assessment of stream quality. This report describes protocols for collecting streamflow, water-quality, streambed-sediment, periphyton, macroinvertebrate, fish, and habitat data as part of the city of Wichita's hydrobiological monitoring program (HBMP). Following consistent and reliable methods for data collection and processing is imperative for the long-term success of the monitoring program.

  14. The Mass-Dimension Relationships in the Mussels Mytilus Galloprovincialis (Mollusca, Bivalvia from Different Phenotypical Groups in Periphyton Populations near Odessa Coast, the North-Western Part of Black Sea

    Directory of Open Access Journals (Sweden)

    Govorin I. A.

    2016-06-01

    Full Text Available The data of the size-mass indices in the mussels Mytilus galloprovincialis (Lamarck, 1819 from three phenotypic groups - brown, dark violet (black and “zebra” (brown with radial black stripes shells in the periphyton settlements on the concrete traverses near Odessa coast, the North-western part of Black Sea (Ukraine, in March-November 2014-2015 are presented. A comparative evaluation has been made on the relationships of total mass of the mollusks, wet and dry mass of their soft body and mass of the shells on the one hand, and the size of animals (length of its shells on the other hand, in the each of phenotypical groups from the five marine beach areas. It is shown, that in the marine areas with different degrees of isolation from the open sea by coast-protection engineering constructions, the mussels from different phenotypes have almost the same size-mass characteristics. Only the dry weight of soft animal body, which indicated to fatness of mollusk and therefore demonstrated his biological prosperity in specific hydrological conditions, can serve as a reliable criterion which can mark the shellfish habitats with different gradients of environmental factors.

  15. Toxicity of the pharmaceutical clotrimazole to marine microalgal communities

    International Nuclear Information System (INIS)

    Porsbring, Tobias; Blanck, Hans; Tjellstroem, Henrik; Backhaus, Thomas

    2009-01-01

    Clotrimazole belongs to the group of 14α-demethylase inhibiting fungicides. It is widely used in human and veterinary medicine and has been identified as a priority pollutant for the marine environment. However, the toxicity of clotrimazole to marine primary producers is largely unknown. We therefore sampled natural microalgal communities (periphyton) and exposed them to concentration series of clotrimazole over 4 days. 50 pmol/L clotrimazole caused a concentration-dependent accumulation of C14α-methylated sterol precursors, which coincided with a decrease in algal-specific C14-desmethyl sterols. This indicates an inhibition of algal 14α-demethylases already at environmental concentrations. A clotrimazole concentration of 500 pmol/L reduced total sterol content to 64% of control level. Community chlorophyll a content was affected by clotrimazole in a bi-phasic manner with first reductions becoming visible at 500 pmol/L, along with indications of an altered cycling of photoprotective xanthophyll pigments. Concentrations of 10-100 nmol/L and higher caused large reductions in community growth, and changed community pigment profiles in a concentration-dependent monotonous manner. The study further indicated that diatoms use obtusifoliol as a natural substrate for 14α-demethylase, just as higher plants do but also utilize norlanosterol

  16. Long-term changes in community assembly, resistance, and resilience following experimental floods.

    Science.gov (United States)

    Robinson, Christopher T

    2012-10-01

    This study examined the long-term changes in community assembly, resistance, and resilience of macroinvertebrates following 10 years of experimental floods in a flow regulated river. Physico-chemistry, macroinvertebrates, and periphyton biomass were monitored before and sequentially after each of 22 floods, and drift/seston was collected during six separate floods over the study period. The floods reduced the density and taxon richness of macroinvertebrates, and a nonmetric dimensional scaling (NMDS) analysis distinguished temporal shifts in community assembly. Resistance (measured as the relative lack of loss in density) tofloods varied among taxa, and the abundance of resistant taxa was related to the temporal changes in community assembly. Community resistance was inversely related to flood magnitude with all larger floods (> 25 m3/s, > 16-fold over baseflow) reducing densities by > 75% regardless of flood year, whereas smaller floods (floods. No relationship was found between flood magnitude and the relative loss in periphyton biomass. Resilience was defined as the recovery slope (positive slope of a parameter with time following each flood) and was unrelated to shifts in community assembly or resistance. Macroinvertebrate drift and seston demonstrated hysteresis (i.e., a temporal response in parameter quantity with change in discharge) during each flood, although larger floods typically had two peaks in both parameters. The first peak was a response to the initial increases in flow, whereas the second peak was associated with streambed disturbance (substrate mobility) and side-slope failure causing increased scour. Drift density was 3-9 times greater and that of seston 3-30 times greater during larger floods than smaller floods. These results demonstrate temporal shifts in macroinvertebrate community assembly toward a pre-dam assemblage following sequential floods in this flow regulated river, thus confirming the ecological role of habitat filtering in

  17. Profile of microbial communities on carbonate stones of the medieval church of San Leonardo di Siponto (Italy) by Illumina-based deep sequencing.

    Science.gov (United States)

    Chimienti, Guglielmina; Piredda, Roberta; Pepe, Gabriella; van der Werf, Inez Dorothé; Sabbatini, Luigia; Crecchio, Carmine; Ricciuti, Patrizia; D'Erchia, Anna Maria; Manzari, Caterina; Pesole, Graziano

    2016-10-01

    Comprehensive studies of the biodiversity of the microbial epilithic community on monuments may provide critical insights for clarifying factors involved in the colonization processes. We carried out a high-throughput investigation of the communities colonizing the medieval church of San Leonardo di Siponto (Italy) by Illumina-based deep sequencing. The metagenomic analysis of sequences revealed the presence of Archaea, Bacteria, and Eukarya. Bacteria were Actinobacteria, Proteobacteria, Bacteroidetes, Cyanobacteria, Chloroflexi, Firmicutes and Candidatus Saccharibacteria. The predominant phylum was Actinobacteria, with the orders Actynomycetales and Rubrobacteriales, represented by the genera Pseudokineococcus, Sporichthya, Blastococcus, Arthrobacter, Geodermatophilus, Friedmanniella, Modestobacter, and Rubrobacter, respectively. Cyanobacteria sequences showing strong similarity with an uncultured bacterium sequence were identified. The presence of the green algae Oocystaceae and Trebuxiaceae was revealed. The microbial diversity was explored at qualitative and quantitative levels, evaluating the richness (the number of operational taxonomic units (OTUs)) and the abundance of reads associated with each OTU. The rarefaction curves approached saturation, suggesting that the majority of OTUs were recovered. The results highlighted a structured community, showing low diversity, made up of extremophile organisms adapted to desiccation and UV radiation. Notably, the microbiome appeared to be composed not only of microorganisms possibly involved in biodeterioration but also of carbonatogenic bacteria, such as those belonging to the genus Arthrobacter, which could be useful in bioconservation. Our investigation demonstrated that molecular tools, and in particular the easy-to-run next-generation sequencing, are powerful to perform a microbiological diagnosis in order to plan restoration and protection strategies.

  18. Epilithic algal assemblages in the Forsmark Biotest basin

    Energy Technology Data Exchange (ETDEWEB)

    Snoeijs, P.

    1987-04-01

    The Forsmark Biotest Basin is an artificial offshore brackish lake, through which the cooling water is led from the Forsmark Nuclear Power Station on the Swedish east coast. The Biotest Basin differs from the Bothnian Sea surrounding it by a temperature elevation of up to 10 degrees C, no ice cover in winter, and an artificial, fast current. At 11 sites in- and outside the basin, benthic algal assemblages on stones in the hydrolittoral belt were sampled every third week during one year. Cover abundances were estimated for all algae occurring on the stones, but for diatoms only when they formed blooms. The results of the vegetation analyses are given. Diversity indices and dominance-diversity curves were computed for each site on the basis of pooled data for the cold season and for the rest of the year. The algae included both unicellular and multicellular forms. In total 88 taxa were distinguished in the species lists: 29 Cyanophyta, 7 Rhodophyta, 1 Chrysophyceae, 9 Fucophyceae, 17 Diatomophyceae and 25 Chlorophyta. In terms of percentage cover-abundance, blue-green and green algae increased with temperature, while red and brown algae and diatoms decreased with temperature in the interval between the minimum (0 degrees C) and the maximum (25.7 degrees C) water temperatures that were measured during the investigation period. Melosira spp. and Nitzschia filiformis proved to be the diatoms most favoured by the cooling water discharge. Lower diversity and greater dominance of one or a few species over the other was caused by thermal discharge at sites with fast-flowing water, but the opposite occurred at sites with quiescent water, mainly due to a greater number and higher abundances of blue-green algal species and thread-like green algae at the latter sites. This report also gives some notes on taxonomy of the encountered species.

  19. Shallow water marine sediment bacterial community shifts along a natural CO2 gradient in the Mediterranean Sea off Vulcano, Italy.

    Science.gov (United States)

    Kerfahi, Dorsaf; Hall-Spencer, Jason M; Tripathi, Binu M; Milazzo, Marco; Lee, Junghoon; Adams, Jonathan M

    2014-05-01

    The effects of increasing atmospheric CO(2) on ocean ecosystems are a major environmental concern, as rapid shoaling of the carbonate saturation horizon is exposing vast areas of marine sediments to corrosive waters worldwide. Natural CO(2) gradients off Vulcano, Italy, have revealed profound ecosystem changes along rocky shore habitats as carbonate saturation levels decrease, but no investigations have yet been made of the sedimentary habitat. Here, we sampled the upper 2 cm of volcanic sand in three zones, ambient (median pCO(2) 419 μatm, minimum Ω(arag) 3.77), moderately CO(2)-enriched (median pCO(2) 592 μatm, minimum Ω(arag) 2.96), and highly CO(2)-enriched (median pCO(2) 1611 μatm, minimum Ω(arag) 0.35). We tested the hypothesis that increasing levels of seawater pCO(2) would cause significant shifts in sediment bacterial community composition, as shown recently in epilithic biofilms at the study site. In this study, 454 pyrosequencing of the V1 to V3 region of the 16S rRNA gene revealed a shift in community composition with increasing pCO(2). The relative abundances of most of the dominant genera were unaffected by the pCO(2) gradient, although there were significant differences for some 5 % of the genera present (viz. Georgenia, Lutibacter, Photobacterium, Acinetobacter, and Paenibacillus), and Shannon Diversity was greatest in sediments subject to long-term acidification (>100 years). Overall, this supports the view that globally increased ocean pCO(2) will be associated with changes in sediment bacterial community composition but that most of these organisms are resilient. However, further work is required to assess whether these results apply to other types of coastal sediments and whether the changes in relative abundance of bacterial taxa that we observed can significantly alter the biogeochemical functions of marine sediments.

  20. Community Economics

    OpenAIRE

    武藤, 宣道; Nobumichi, MUTOH

    2000-01-01

    This paper examines the new field of community economics with respect to Japan. A number of studies in community economics have already been produced in OECD countries including the United States. Although these are of great interest, each country has its own historical, socioeconomic context and must therefore develop its own approach to community economics. Community-oriented economics is neither macro-nor micro-economics in the standard economics textbook sense. Most community economics st...

  1. Investigation of road salts and biotic stressors on freshwater wetland communities.

    Science.gov (United States)

    Jones, Devin K; Mattes, Brian M; Hintz, William D; Schuler, Matthew S; Stoler, Aaron B; Lind, Lovisa A; Cooper, Reilly O; Relyea, Rick A

    2017-02-01

    The application of road deicing salts has led to the salinization of freshwater ecosystems in northern regions worldwide. Increased chloride concentrations in lakes, streams, ponds, and wetlands may negatively affect freshwater biota, potentially threatening ecosystem services. In an effort to reduce the effects of road salt, operators have increased the use of salt alternatives, yet we lack an understanding of how these deicers affect aquatic communities. We examined the direct and indirect effects of the most commonly used road salt (NaCl) and a proprietary salt mixture (NaCl, KCl, MgCl 2 ), at three environmentally relevant concentrations (150, 470, and 780 mg Cl - /L) on freshwater wetland communities in combination with one of three biotic stressors (control, predator cues, and competitors). The communities contained periphyton, phytoplankton, zooplankton, and two tadpole species (American toads, Anaxyrus americanus; wood frogs, Lithobates sylvaticus). Overall, we found the two road salts did not interact with the natural stressors. Both salts decreased pH and reduced zooplankton abundance. The strong decrease in zooplankton abundance in the highest NaCl concentration caused a trophic cascade that resulted in increased phytoplankton abundance. The highest NaCl concentration also reduced toad activity. For the biotic stressors, predatory stress decreased whereas competitive stress increased the activity of both tadpole species. Wood frog survival, time to metamorphosis, and mass at metamorphosis all decreased under competitive stress whereas toad time to metamorphosis increased and mass at metamorphosis decreased. Road salts and biotic stressors can both affect freshwater communities, but their effects are not interactive. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Stressor-Response Models Relating Nutrient Enrichment to Algal Communities in Pacific Northwest Streams and Rivers

    Science.gov (United States)

    Sobota, D. J.; Hubler, S.; Paul, M. J.; Labiosa, R.

    2015-12-01

    Excessive algal growth in streams and rivers from nutrient enrichment can cause costly human health and environmental problems. As part of the US Environmental Protection Agency's Nutrient Scientific Technical Exchange Partnership and Support (N-STEPS) program, we have been developing stressor-response (S-R) models relating nutrients to attached algal (periphyton) communities to help prioritize monitoring for water quality impairments in Oregon (Pacific Northwest, USA) streams and rivers. Existing data from the state and neighboring states were compiled and standardized from the Oregon Department of Environmental Quality, US Environmental Protection Agency, and the US Geological Survey. To develop S-R models, algal community and biomass metrics were compared with nitrogen (N) and phosphorus (P) concentration data, including total, dissolved, and inorganic forms of these nutrients. In total, 928 paired algal-nutrient samples were compiled from the 8 Level-III Ecoregions occurring in Oregon. Relationships between algal biomass metrics and nutrient concentrations were weak, with only ash-free dry mass and standing stock of chlorophyll a showing slight positive relationships across gradients of total N and soluble reactive P concentrations, respectively. In contrast, metrics describing algal community composition, including percent diatoms and abundance of nutrient-sensitive species, showed very strong nonlinear relationships with total N or P concentrations. This suggests that data describing algal community composition can help identify specific nutrient stressors across environmentally-diverse streams and rivers in the Pacific Northwest. Future analyses will examine if nutrient-algal S-R models vary across different hydrological, physiographical, and ecological settings in the region.

  3. Community relations

    International Nuclear Information System (INIS)

    O'Neil, C.

    1997-01-01

    The interaction of the oil and gas companies with the Northern communities regarding drilling activities was an important aspect of oil and gas operations conducted in the Beaufort Sea. During the 1960s the industry and aboriginal people basically ignored each other. Later, the industry put more emphasis on community consultation until finally two-way communication was established. Respect for the land and the environment were very important to aboriginal people who depended on the land and its resources for their traditional way of life. Community relations policies by the various companies involved in the area, and the impact they have had on their respective communities were recounted. Not all efforts were successful, however, the companies and the communities learned from their experiences, and by the time operations ceased, the communities seemed to be more appreciative of the ways they were being treated by the oil companies. 22 figs

  4. Claiming Community

    DEFF Research Database (Denmark)

    Jensen, Steffen Bo

    As its point of departure this working paper takes the multitude of different uses and meanings of the concept of community in local politics in Cape Town. Instead of attempting to define it in substantive terms, the paper takes a social constructivist approach to the study of community...... is termed community work. First, the paper explores how community has become a governmental strategy, employed by the apartheid regime as well, although in different ways, as post-apartheid local government. Secondly, the paper explores the ways in which community becomes the means in which local residents...... lay claim on the state, as well as how it enters into local power struggles between different political groups within the township. In the third part, the paper explores how the meanings of community and the struggles to realise it have changed as South Africa, nationally and locally, has become...

  5. Effects of land use, stream habitat, and water quality on biological communities of wadeable streams in the Illinois River Basin of Arkansas, 2011 and 2012

    Science.gov (United States)

    Petersen, James C.; Justus, B.G.; Meredith, Bradley J.

    2014-01-01

    The Illinois River Basin includes an area of diverse land use in northwestern Arkansas. Land-use data collected in 2006 indicate that most of the land in the basin is agricultural. The agricultural land is used primarily for production of poultry and cattle. Eighteen sites were selected from the list of candidate sites based on drainage area, land use, presence or absence of an upstream wastewater-treatment plant, water quality, and other information gathered during the reconnaissance. An important consideration in the process was to select sites along gradients of forest to urban land use and forest to agricultural land use. Water-quality samples were collected for analysis of nutrients, and a multiparameter field meter was used to measure water temperature, specific conductance, pH, and dissolved oxygen. Streamflow was measured immediately following the water-quality sampling. Macroalgae coverage was estimated and periphyton, macroinvertebrate, and fish communities were sampled at each site. Stream habitat also was assessed. Many types of land-use, water-quality, and habitat factors affected one or more aspects of the biological communities. Several macroinvertebrate and fish metrics changed in response to changes in percent forest; sites that would be considered most disturbed, based on these metrics, are sites with the highest percentages of urban land use in their associated basins. The presence of large mats of macroalgae was one of the most noticeable biological characteristics in several streams within the Illinois River Basin. The highest macroalgae percent cover values were recorded at four sites downstream from wastewater-treatment plants. Macroalgae percent cover was strongly correlated only with bed substrate size, canopy closure, and specific conductance. Periphyton metrics were most often and most strongly correlated with riparian shading, specific conductance, substrate turbidity, percent agriculture, poultry house density, and unpaved road density

  6. Biclique communities

    DEFF Research Database (Denmark)

    Jørgensen, Sune Lehmann; Hansen-Schwartz, Martin; Hansen, Lars Kai

    2008-01-01

    We present a method for detecting communities in bipartite networks. Based on an extension of the k-clique community detection algorithm, we demonstrate how modular structure in bipartite networks presents itself as overlapping bicliques. If bipartite information is available, the biclique...... community detection algorithm retains all of the advantages of the k-clique algorithm, but avoids discarding important structural information when performing a one-mode projection of the network. Further, the biclique community detection algorithm provides a level of flexibility by incorporating independent...

  7. [Community Nutrition].

    Science.gov (United States)

    Aranceta, Javier

    2004-06-01

    In the last 20 years, Public Health Nutrition focused mainly on the qualitative aspects which may influence the onset of chronic diseases, quality of life, physical and mental performance and life expectancy. This applied knowledge organised as part of preventive and health promotion programs led to the development of Community Nutrition. The aim of Community Nutrition actions is to adequate lifestyles related to food consumption patterns in order to improve the quality of life and contribute to health promotion of the population in the community where programs and services are delivered. Key functions to develop in a Community Nutrition Unit consist in the identification and assessment of nutrition problems in the community as well as the design, implementation and evaluation of intervention programs by means of appropriate strategies. These should aim at different populations groups and settings, such as work places, schools, high risk groups or the general public. Nowadays, Community Nutrition work efforts should focus on three main aspects: nutrition education in schools and in the community; food safety and food security and the development and reinforcement of food preparation skills across all age groups. Social catering services, either in schools, the work place or at the community level, need to ensure adequate nutritional supply, provide foods contributing to healthy eating practices as well as to enhance culinary traditions and social learning. Food safety and food security have become a top priority in Public Health. The concepts referes to the availability of food safe and adequate as well as in sufficient amount in order to satisfy nutrition requirements of all individuals in the community. Social changes along new scientific developments will introduce new demands in Community Nutrition work and individual dietary counselling will become a key strategy. In order to face new challenges, community nutrition pactitioners require a high quality

  8. If you see one, have you seen them all?: Community-wide effects of insecticide cross-resistance in zooplankton populations near and far from agriculture.

    Science.gov (United States)

    Bendis, Randall J; Relyea, Rick A

    2016-08-01

    The worldwide use of pesticides has led to increases in agricultural yields by reducing crop losses. However, increased pesticide use has resulted in pesticide-resistant pest species and recent studies have discovered pesticide-resistance in non-target species living close to farms. Such increased tolerance not only affects the species, but can alter the entire food web. Given that some species can evolve not only resistance to a single pesticide, but also cross-resistance to other pesticides that share the same mode of action, one would predict that cross-resistance to pesticides would also have effects on the entire community and affect community stability. To address this hypothesis, we conducted an outdoor mesocosm experiment comprised of 200 identical aquatic communities with phytoplankton, periphyton, and leopard frog (Lithobates pipiens) tadpoles. To these communities, we added one of four Daphnia pulex populations that we previously discovered were either resistant or sensitive to the insecticide of chlorpyrifos as a result of living close to or far from agriculture, respectively. We then exposed the communities to either no insecticide or three different concentrations of AChE-inhibiting insecticides (chlorpyrifos, malathion or carbaryl) or sodium channel-inhibiting insecticides (permethrin or cypermethrin). We discovered that communities containing sensitive Daphnia pulex experienced phytoplankton blooms and subsequent cascades through all trophic groups including amphibians at moderate to high concentrations of all five insecticides. However, communities containing resistant D. pulex were buffered from these effects at low to moderate concentrations of all AChE-inhibiting insecticides, but were not buffered against the pyrethroid insecticides. These data suggest that a simple change in the population-level resistance of zooplankton to a single insecticide can have widespread consequences for community stability and that the effects can be extrapolated

  9. Community noise

    Science.gov (United States)

    Bragdon, C. R.

    Airport and community land use planning as they relate to airport noise reduction are discussed. Legislation, community relations, and the physiological effect of airport noise are considered. Noise at the Logan, Los Angeles, and Minneapolis/St. Paul airports is discussed.

  10. 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...

  11. Community Ecology

    CERN Document Server

    1988-01-01

    This book presents the proceedings of a workshop on community ecology organized at Davis, in April, 1986, sponsored by the Sloan Foundation. There have been several recent symposia on community ecology (Strong et. al., 1984, Diamond and Case, 1987) which have covered a wide range of topics. The goal of the workshop at Davis was more narrow: to explore the role of scale in developing a theoretical approach to understanding communities. There are a number of aspects of scale that enter into attempts to understand ecological communities. One of the most basic is organizational scale. Should community ecology proceed by building up from population biology? This question and its ramifications are stressed throughout the book and explored in the first chapter by Simon Levin. Notions of scale have long been important in understanding physical systems. Thus, in understanding the interactions of organisms with their physical environment, questions of scale become paramount. These more physical questions illustrate the...

  12. European Community.

    Science.gov (United States)

    1987-05-01

    The European Community was established in 1951 to reconcile France and Germany after World War II and to make possible the eventual federation of Europe. By 1986, there were 12 member countries: France, Italy, Belgium, the Federal Republic of Germany, Luxembourg, the Netherlands, Denmark, Ireland, the United Kingdom, Greece, Spain, and Portugal. Principal areas of concern are internal and external trade, agriculture, monetary coordination, fisheries, common industrial and commercial policies, assistance, science and research, and common social and regional policies. The European Community has a budget of US$34.035 billion/year, funded by customs duties and 1.4% of each member's value-added tax. The treaties establishing the European Community call for members to form a common market, a common customs tariff, and common agricultural, transport, economic, and nuclear policies. Major European Community institutions include the Commission, Council of Ministers, European Parliament, Court of Justice, and Economic and Social Committee. The Community is the world's largest trading unit, accounting for 15% of world trade. The 2 main goals of the Community's industrial policy are to create an open internal market and to promote technological innovation in order to improve international competitiveness. The European Community aims to contribute to the economic and social development of Third World countries as well.

  13. Natural Communities

    Data.gov (United States)

    Kansas Data Access and Support Center — This dataset shows the locations of known tracts of high quality natural communities in Kansas, generalized to the PLSS section. It is not a compehensive dataset of...

  14. COMMUNITY OPHTHALMOLOGY

    African Journals Online (AJOL)

    2016-11-04

    Nov 4, 2016 ... The Role of Research in Social Marketing: The Community Eye. Outreach Clinic .... Serious thought was given to the possibility of establishing static eye care .... Information obtained included vital statistics, work history, job.

  15. Community concepts.

    Science.gov (United States)

    Yeung, Thomas; Bates, Tony

    2004-03-01

    Since the publication of "Sustainable Communities--building for the future", Government attention has focused largely on high-density affordable housing in the four "growth areas": Thames Gateway; Ashford; Milton Keynes--South Midlands, and London--Stansted--Cambridge. In this article, Thomas Yeung and Tony Bates suggest that a greater and more sustainable impact would be achieved if architects, planners, and developers considered the potential for community-based water and waste management and on-site energy generation and distribution right from the start of the project. In particular, they consider that the communal nature of hospitals, universities, and public/community housing provides a great opportunity for on-site renewable CHP and/or distributed heating, which could combine global environmental benefits with improved local amenities. They describe a simple model for prioritising energy management in the built environment, and draw on lessons learnt at ETRCL in Dagenham and BedZED in Surrey to offer a few recommendations for Government and developers. Tony Bates is the business development manager for Scott Wilson in the South East and is responsible for the promotion of sustainable communities through relationships with architects, developers, land owners and local authorities. Thomas Yeung leads the Energy Infrastructure Technologies group in Scott Wilson. This team offers an integrated approach to clean community-based energy generation, energy management, waste and water management, sustainable transport, and sustainable buildings/communities.

  16. Community expectations

    International Nuclear Information System (INIS)

    Kraemer, L.

    2004-01-01

    Historically, the relationship between the nuclear generator and the local community has been one of stability and co-operation. However in more recent times (2000-2003) the nuclear landscape has had several major issues that directly effect the local nuclear host communities. - The associations mandate is to be supportive of the nuclear industry through ongoing dialogue, mutual cooperation and education, - To strengthen community representation with the nuclear industry and politically through networking with other nuclear host communities. As a result of these issues, the Mayors of a number of communities started having informal meetings to discuss the issues at hand and how they effect their constituents. These meetings led to the official formation of the CANHC with representation from: In Canada it is almost impossible to discuss decommissioning and dismantling of Nuclear Facilities without also discussing Nuclear Waste disposal for reasons that I will soon make clear. Also I would like to briefly touch on how and why expectation of communities may differ by geography and circumstance. (author)

  17. Mechanisms regulating amphipod population density within macroalgal communities with low predator impact

    Directory of Open Access Journals (Sweden)

    Hartvig Christie

    2004-04-01

    Full Text Available In eight mesocosms (land based basins macroalgae communities with associated fauna were transplanted from the sea and established during two years. Then, different doses of nutrients (N and P were added to the basins throughout the following three years. During the period of nutrient addition, macroinvertebrate grazers showed seasonal fluctuations with densities usually between 500,000 and 1 million individuals per mesocosm during summer and to a level of about 100,000 during winter. The macroinvertebrate grazers mainly consisted of about 10 species of amphipods and isopods, among which the amphipod Gammarus locusta dominated strongly by biomass. Although the number of predators was very low, the grazer populations never reached a density where considerable grazing impact could be found on the macroalgae. No increase in grazer density was found in the basins with improved nutrient conditions. Thus food quality may be insufficient for further population growth, or density dependant regulation mechanisms may have prevented the grazers from flourishing and overgrazing the system. In aquarium experiments we showed that G. locusta could grow and reproduce on Fucus serratus, Ulva lactuca, periphyton and detritus, and that cannibalism by adult G. locusta on juveniles may have great impact on the population growth. The basins were run with a water flow through system. Nets were placed in front of the inflow and outflow tubes to measure immigration and emigration. Only few individuals (and no Gammarus sp. were recorded in the inflowing water, while high numbers of both amphipods and isopods were found in the outflowing water. Emigration reached peak values during night-time, and it was then two to three times as high as during day-time. Emigration of mobile grazers from the basins amounted to 1-2% of the standing stock daily. These mechanisms that regulate grazers do contribute to maintenance of the seaweed dominance and thus the stability of the seaweed

  18. Designed communities?

    DEFF Research Database (Denmark)

    Stender, Marie

    2013-01-01

    In current residential spaces there seem to be an increasing emphasis on small-scale communities. A number of new, high profiled residential complexes thus seek to promote new ways of social living by rethinking architectural design, typologies and concepts. In this paper I explore the emergence ...

  19. Walkable Communities

    Centers for Disease Control (CDC) Podcasts

    2008-04-18

    This podcast is for a general audience and discusses the benefits of walkable communities, as they relate to health, the environment, and social interaction.  Created: 4/18/2008 by National Center for Environmental Health (NCEH), ATSDR.   Date Released: 5/8/2008.

  20. Interfirm communities

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten

    2012-01-01

    . These results yield a paradox which the present paper aims to address. Based on an in-depth case study of how a high-tech small firm organizes its interfirm activity, I show how a hybrid social relation, that is neither weak nor strong, is a useful conception for interfirm communities. Hereby, the study also...

  1. Community Evolution

    OpenAIRE

    Saganowski, Stanisław; Bródka, Piotr; Kazienko, Przemysław

    2016-01-01

    The continuous interest in the social network area contributes to the fast development of this field. The new possibilities of obtaining and storing data facilitate deeper analysis of the entire social network, extracted social groups and single individuals as well. One of the most interesting research topic is the network dynamics and dynamics of social groups in particular, it means analysis of group evolution over time. It is the natural step forward after social community extraction. Havi...

  2. Online Communities

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Lassen, Astrid Heidemann; Gorm Hansen, Katrine

    ”Online Communities” er et medie for brugere og fagfolk, hvor de kan mødes digitalt for at dele erfaringer, og dette kan anvendes som inspiration indenfor Brugerdreven Innovation. Via ”desk research” kan virksomheder opnå adgang til varierende mængder af brugere på en forholdsvist enkelt måde. I...... denne rapport beskrives eksperimentets opbygning, resultater og mulige værdi. Vi håber hermed på at kunne give praktisk indsigt i, hvorledes virksomheder fra byggematerialeindustrien kan agere i online communities....

  3. Responses of Chironomidae (Diptera; Insecta to the exclusion of shrimps and Ephemeroptera in a coastal forest stream, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    ML. Souza

    Full Text Available In a benthic community on a continuous flat granite substrate in a third-order coastal forest stream, the dominant chironomid (Cricotopus increased in number when shrimps (Macrobrachium olfersi and Potimirim glabra and baetid ephemeropterans were excluded by electricity. The response appeared to be mediated by an increase in periphyton and sediments, rather than a reduction of direct predation or interference. Chironomids, periphyton and sediments decreased significantly compared to the control when shrimps only were excluded. Baetid ephemeropteran appeared to be the most important determinants of periphyton and sediment mass; the density of chironomids appeared to follow the quantity of periphyton and sediments.

  4. Developing Learning Communities: Using Communities of Practice within Community Psychology

    Science.gov (United States)

    Lawthom, Rebecca

    2011-01-01

    The idea that communities need to be inclusive is almost axiomatic. The process, whereby, community members engage in inclusive practices is far less understood. Similarly, UK universities are being encouraged to include the wider community and extent campus boundaries. Here, I suggest a particular theoretical lens which sheds light on engagement…

  5. Microscopic Analysis of Plankton, Periphyton, and Activated Sludge. Training Manual.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    This manual is intended for professional personnel in the fields of water pollution control, limnology, water supply and waste treatment. Primary emphasis is given to practice in the identification and enumeration of microscopic organisms which may be encountered in water and activated sludge. Methods for the chemical and instrumental evaluation…

  6. Downstream changes in spring-fed stream invertebrate communities: the effect of increased temperature range?

    Directory of Open Access Journals (Sweden)

    Russell G. DEATH

    2011-09-01

    Full Text Available Reduced thermal amplitude has been highlighted as a limiting factor for aquatic invertebrate diversity in springs. Moving downstream water temperature range increases and invertebrate richness is expected to change accordingly. In the present study temperature patterns were investigated in seven spring-fed streams, between April 2001 and November 2002, and compared to five run-off-fed streams to assess the degree of crenic temperature constancy. Temperature and physico-chemical characteristics of the water, and food resource levels were measured, and the invertebrate fauna collected at 4 distances (0, 100, 500 m and 1 km from seven springs in the North and South Islands of New Zealand. Temperature variability was greater for run-off-fed streams than for springs, and increased in the spring-fed streams with distance from the source. Periphyton and physico-chemical characteristics of the water did not change markedly over the 1 km studied, with the exception of water velocity and organic matter biomass, which increased and decreased, respectively. The rate of increase in temperature amplitude differed greatly for the studied springs, probably being affected by flow, altitude, and the number and type of tributaries (i.e., spring- or run-off-fed joining the spring-fed stream channel. Longitudinal changes in the number and evenness of invertebrate taxa were positively correlated to thermal amplitude (rs = 0.8. Moving downstream, invertebrate communities progressively incorporated taxa with higher mobility and taxa more common in nearby run-off-fed streams. Chironomids and non-insect taxa were denser at the sources. Chironomid larvae also numerically dominated communities 100 and 500 m downstream from the sources, together with Pycnocentria spp. and Zelolessica spp., while taxa such as Hydora sp. and Hydraenidae beetles, the mayflies Deleatidium spp. and Coloburiscus humeralis, and the Trichoptera Pycnocentrodes spp., all had greater abundances 1 km

  7. Community Hospital Telehealth Consortium

    National Research Council Canada - National Science Library

    Williams, Elton

    2004-01-01

    The Community Hospital Telehealth Consortium is a unique, forward-thinking, community-based healthcare service project organized around 5 not-for-profit community hospitals located throughout Louisiana and Mississippi...

  8. Involving the Community

    International Development Research Centre (IDRC) Digital Library (Canada)

    Step 3: Identifying the different community groups and other stakeholders concerned .... How can two-way communication enhance community participation in ...... for maintenance and the rights of specific community groups to drinkable water.

  9. Community Hospital Telehealth Consortium

    National Research Council Canada - National Science Library

    Williams, Elton

    2003-01-01

    The Community Hospital Telehealth Consortium is a unique, forward-thinking, community-based healthcare service project organized around 5 not-for-profit community hospitals located throughout Louisiana and Mississippi...

  10. Community Hospital Telehealth Consortium

    National Research Council Canada - National Science Library

    Williams, Jr, Elton L

    2007-01-01

    The Community Hospital Telehealth Consortium is a unique, forward-thinking, community-based healthcare service project organized around 5 not-for-profit community hospitals located throughout Louisiana and Mississippi...

  11. Community Mentoring: A Tool for Successful Communities

    Science.gov (United States)

    Dodge, Kathryn E.

    2015-01-01

    Mentoring occurs in an ad hoc and largely invisible manner in communities. This mentoring happens through modeling, storytelling, and asking open-ended questions. If Extension specialists and agents were more conscious and intentional about teaching community members and leaders about community mentoring, they would be more successful in resolving…

  12. Keeping "Community" in a Community Land Trust

    Science.gov (United States)

    Gray, Karen A.; Galande, Mugdha

    2011-01-01

    This instrumental case study examined the role of grassroots community organizing in a community land trust (CLT) in a southern U.S. city. Twenty-nine homeowners, renters, board members, community members, and current and former CLT employees were interviewed. In addition, two focus groups of 11 and six participants composed of CLT residents and…

  13. On Community Education and Community Development

    Directory of Open Access Journals (Sweden)

    Dušana Findeisen

    1996-12-01

    Full Text Available In this paper Dušana Findeisen introduces community education and development. She particularly insists upon the fact that in the future our life will not be organised around a paid full time job and that we will be forced into searching other ways of getting involved into society and to acquire our social identity. Community education is one of the ways we could eventually choose. Since community development education in Slovenia has not developed yet the author begins by describing some basic concepts like community and history of community education and community development movement. Further on, she introduces the Andragogical Summer School based in a small Slovenian town, its aim being to encourage Slovenian adult educators to encourage community development projects.

  14. Spatial Patterns in Biofilm Diversity across Hierarchical Levels of River-Floodplain Landscapes.

    Directory of Open Access Journals (Sweden)

    Marc Peipoch

    Full Text Available River-floodplain systems are among the most diverse and productive ecosystems, but the effects of biophysical complexity at multiple scales on microbial biodiversity have not been studied. Here, we investigated how the hierarchical organization of river systems (i.e., region, floodplain, zone, habitats, and microhabitats influences epilithic biofilm community assemblage patterns by characterizing microbial communities using 16S rRNA gene sequence data and analyzing bacterial species distribution across local and regional scales. Results indicate that regional and local environmental filters concurrently sort bacterial species, suggesting that spatial configuration of epilithic biofilms resembles patterns of larger organisms in floodplain ecosystems. Along the hierarchical organization of fluvial systems, floodplains constitute a vector of maximum environmental heterogeneity and consequently act as a major landscape filter for biofilm species. Thus, river basins and associated floodplains may simply reflect very large scale 'patches' within which environmental conditions select for community composition of epilithic biofilms.

  15. Community development planning

    International Nuclear Information System (INIS)

    Gray, S.I.

    1983-01-01

    The focus of this paper will be methods of local community involvement in the community development planning efforts which will be required at the recommended sites. Community development planning will include capital improvement plans, housing plans, zoning changes, business development plans and other community service and fiscal plans required to meet the projected needs of new residents as a result of the repository construction and operation. This paper will present, (1) the need for community planning, (2) methods of responding to community planning needs, (3) current community planning issues to be addressed. 2 references, 1 figure

  16. Ecological Study of Periphytic Algal Community of Doodh Ganga and Khansha-Mansha Streams of Yusmarg Forests: A Health Resort of Kashmir Valley, India

    Directory of Open Access Journals (Sweden)

    Rafia Rashid

    2013-06-01

    Full Text Available The present study on Doodh Ganga and Khansha-Mansha streams of Yusmarg forests deals with the general ecological studies on periphytic algal community in terms of species composition and density. During the present investigation the periphytic algal community of Doodh Ganga and Khansha-Mansha streams were represented by 30 taxa which belonged to 4 major classes namely Bacillariophyceae (14, Chlorophyceae (11, Cyanophyceae (4 and Euglenophyceae (1. The most common periphytic species encountered across all the sites included Closterium sp., Zygnema sp., Amphora sp., Cymbella sp., Epithemia sp., Fragilaria sp., Navicula sp., Synedra sp., Tabellaria sp., Lyngbya sp. and Phormidium sp. Among the two streams, Doodh Ganga showed large number of taxa (45 and Khansha-Mansha was having 37 taxa of periphyton. Bacillariophyceae was the dominant group both in diversity and density and included 14 taxa contributing 57% of total periphytic algal population. Cyanophyceae forming the second dominant class was represented by 4 genera comprising 22% of the total periphytic algae .Chlorophyceae ranked third in its dominance pattern with 11 genera forming 20% of all the periphytic algae. Euglenophyceae was represented by only one species of Euglena sp. forming 1% of all the periphytic algae and found only at site 2 (Doodh Ganga downstream.Amongst the study sites the highest (5.69 value of Shannon Weiner Index was found at Doodh Ganga upstream while as lowest (4.38 at Khansha-Mansha downstream. The primary conclusion is that the streams, having crystal clear water, and are free from pollution as Chlorophyceae are better represented in both the streams. Further, as a result of less anthropogenic pressures the quality of water is fairly good.

  17. Rediscovering community: Interethnic relationships and community gardening

    Directory of Open Access Journals (Sweden)

    August John Hoffman

    2010-11-01

    Full Text Available Community service work, volunteerism and mentoring have recently become popular topics of research as effective methods in improving self-esteem and civic responsibility. In the current study we explored the relationship between participation in a community service gardening program and ethnocentrism. We hypothesised that an inverse correlation would emerge where students who participated in a community service-gardening program would increase their perceptions of the importance of community service work and decrease their scores in ethnocentrism. Results of the paired samples t-test strongly support the hypothesis that community service gardening work significantly reduces reports of ethnocentrism: t(10 = -2.52, (p < .03 for community college students. The ramifications of the study and ramifications for future research are offered.

  18. Biomass and relative coverage of benthic algae in the fore-reef of Curacao (Netherlands Antilles) in relation to production

    Energy Technology Data Exchange (ETDEWEB)

    de Ruyter van Stevenick, E.D.; Breeman, A.M.

    1981-11-15

    Biomass of benthic algae, expressed as chlorophyll a content (..mu..g cm/sup -2/) and as dry weight (mg cm/sup -2/) per substrate surface area in the coral reef of Curacao at 12 m and 25 m depth was measured from August 1978 to March 1979. To determine dry weights, substrates containing endolithic and epilithic algae were oxidized by means of wet combustion with hydrogen peroxide. Loss of weight caused by this process was regarded as algal dry weight. The crustose corallines Archaeolithothamnion dimotum Fosl. et Howe (25 m), Hydrolithon boergesenii (Fosl.) Fosl. (12 m and 25 m) and Lithophyllum cf. intermedium Fosl. (12 m), vegetations of endolithic algae dominated by Ostreobium quekettii Born. et Flah. (12 m and 25 m), and mixed turfs of epilithic filamentous algae and sometimes Lithophyllum cf. intermedium on substrates containing endolithic algae (12 m and 25 m) were examined. Chlorophyll a values ranged from 8.7 ..mu..g cm/sup -2/ for H. boergesenii at 12 m to 20.5 ..mu..g cm/sup -2/ for epilithic filamentous algae on substrates containing endolithic algae at 25 m. Dry weights varied from 12.7 mg cm/sup -2/ for L. cf. intermedium at 12 m to 25.7 mg cm/sup -2/ for epilithic filamentous algae on substrates containing endolithic algae at 25 m. Both at 12 m and 25 m, differences in chlorophyll a content and dry weights between substrates containing endolithic algae with and without epilithic filamentous algae were low. Biomass of endolithic algae is quantitatively more important than that of epilithic filamentous algae. It is concluded that, at 12 m, biomass of the algal vegetation as a whole is lowest while production is highest. This is attributed to maximum grazing pressure at this depth ('drop off' community), especially on epilithic filamentous algae.

  19. Community Involvement - Outreach / Development

    OpenAIRE

    2004-01-01

    Tonya Aiken: Horse Program Success. Kyle Cecil: Natural Resources and the Extension Educator. Karol Dyson: Building Strong Communities through Empowerment. Lisa Dennis: "Food Smart". Theresa M. Ferrari: Community Service Experiences & 4-H Teens. t. Stacey Harper: Connecting the Youth with the Community. Joseph G. Hiller: Extension Work in Indian Country. Alice P. Kersey: Outreach to the NR Community. Carla M. Sousa: Learning from Latino Community Efforts.

  20. Multifractal characteristics of NDVI maps in space and time in the Community of Madrid (Spain)

    Science.gov (United States)

    Sotoca, Juan J. Martin; Saa-Requejo, Antonio; Grau, Juan B.; Tarquis, Ana M.

    2015-04-01

    Satellite information has contributed to improve our understanding of the spatial variability of hydro-climatic and ecological processes. Vegetation activity is tightly coupled with climate, hydro-ecological fluxes, and terrain dynamics in river basins at a wide range of space-time scales (Scheuring and Riedi, 1994). Indices of vegetation activity are constructed using satellite information of reflectance of the relevant spectral bands which enhance the contribution of vegetation being Normalized Difference Vegetation Index (NDVI) widely used. How can we study such a complex system? Multifractals and fractals are related techniques mainly used in physics to characterize the scaling behaviour of a system; they differ in that fractals look at the geometry of presence/absence patterns, while multifractals look at the arrangement of quantities such as population or biomass densities (Saravia et al., 2012). Scaling laws are an emergent general feature of ecological systems; they reflect constraints in their organization that can provide tracks about the underlying mechanisms (Solé and Bascompte, 2006). In this work, we have applied these techniques to study the spatial pattern through one year of NDVI maps. A rectangular area that includes the Community of Madrid and part of the surroundings, consisting of 300 x 280 pixels with a resolution of 500 x 500 m2 has been selected and monthly NDVI maps analyzed using the multifractal spectrum and the map of singularities (Cheng and Agterberg, 1996). The results show a cyclical pattern in the multifractal behaviour and singularity points related to river basin networks (Martín-Sotoca, 2014). References Cheng, Q. and Agterberg, F.P. (1996). Multifractal modeling and spatial statistics. Math. Geol. Vol 28, 1-16. Martín-Sotoca, J.J. (2014) Estructura Espacial de la Sequía en Pastos y sus Aplicaciones en el Seguro Agrario. Master Thesis, UPM (In Spanish). Saravia LA, Giorgi A, Momo F.: Multifractal growth in periphyton

  1. The role of hydrodynamics in shaping the composition and architecture of epilithic biofilms in fluvial ecosystems.

    Science.gov (United States)

    Risse-Buhl, Ute; Anlanger, Christine; Kalla, Katalin; Neu, Thomas R; Noss, Christian; Lorke, Andreas; Weitere, Markus

    2017-12-15

    Previous laboratory and on-site experiments have highlighted the importance of hydrodynamics in shaping biofilm composition and architecture. In how far responses to hydrodynamics can be found in natural flows under the complex interplay of environmental factors is still unknown. In this study we investigated the effect of near streambed turbulence in terms of turbulent kinetic energy (TKE) on the composition and architecture of biofilms matured in two mountainous streams differing in dissolved nutrient concentrations. Over both streams, TKE significantly explained 7% and 8% of the variability in biofilm composition and architecture, respectively. However, effects were more pronounced in the nutrient richer stream, where TKE significantly explained 12% and 3% of the variability in biofilm composition and architecture, respectively. While at lower nutrient concentrations seasonally varying factors such as stoichiometry of dissolved nutrients (N/P ratio) and light were more important and explained 41% and 6% of the variability in biofilm composition and architecture, respectively. Specific biofilm features such as elongated ripples and streamers, which were observed in response to the uniform and unidirectional flow in experimental settings, were not observed. Microbial biovolume and surface area covered by the biofilm canopy increased with TKE, while biofilm thickness and porosity where not affected or decreased. These findings indicate that under natural flows where near bed flow velocities and turbulence intensities fluctuate with time and space, biofilms became more compact. They spread uniformly on the mineral surface as a film of densely packed coccoid cells appearing like cobblestone pavement. The compact growth of biofilms seemed to be advantageous for resisting hydrodynamic shear forces in order to avoid displacement. Thus, near streambed turbulence can be considered as important factor shaping the composition and architecture of biofilms grown under natural flows. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The reponse of epilithic diatom assemblages to sewage pollution in mountain streams of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Moravcová, A.; Rauch, Ota; Lukavský, Jaromír; Nedbalová, Linda

    2013-01-01

    Roč. 146, č. 2 (2013), s. 153-166 ISSN 2032-3913 Institutional support: RVO:67985939 Keywords : epilitic diatoms * mountain streams * sewage polllution Subject RIV: EH - Ecology, Behaviour Impact factor: 0.960, year: 2013

  3. Community Bioethics: The Health Decisions Community Council.

    Science.gov (United States)

    Gallegos, Tom; Mrgudic, Kate

    1993-01-01

    Sees health care decision making posing variety of complex issues for individuals, families, and providers. Describes Health Decisions Community Council (HDCC), community-based bioethics committee established to offer noninstitutional forum for discussion of health care dilemmas. Notes that social work skills and values for autonomy and…

  4. University-Community Research Partnership for Community ...

    African Journals Online (AJOL)

    This paper analyses the existing university–community partnership in research in Tanzania and proposes a bottom-top model instead of the traditional top-bottom approach which works with perceived needs of communities rather than real needs. Given their core missions, many universities assume that they achieve their ...

  5. A la Carte Community

    DEFF Research Database (Denmark)

    Gundelach, Peter; Brincker, Benedikte

    2010-01-01

    and shows that there are high levels of virtual as well as face-to-face interaction among the members. The participants feel that they belong to the community and many also feel that they are recognised as part of the community. However, the members do not share common values neither in relation to software......The exchange of open source software is a phenomenon that is becoming in- creasingly significant to IT users. This article presents the results of a study of the TYPO3 community, a community related to an open source CMS software. The article explores the community, identity and values of TYPO3...... pro- duction nor generally. Instead, they stress that you are free to choose your own values. Against this background, the authors introduce the notion of an ‘a la carte community', i.e. a community where individuals pick and choose their degree of participation and integra- tion into the community...

  6. Monitoring natural phytoplankton communities

    DEFF Research Database (Denmark)

    Haraguchi, L.; Jakobsen, H. H.; Lundholm, Nina

    2017-01-01

    The phytoplankton community can vary within hours (physiology) to years (climatic and anthropogenic responses), and monitoring at different timescales is relevant for understanding community functioning and assessing changes. However, standard techniques used in monitoring programmes are time...

  7. Bayesian community detection

    DEFF Research Database (Denmark)

    Mørup, Morten; Schmidt, Mikkel N

    2012-01-01

    Many networks of scientific interest naturally decompose into clusters or communities with comparatively fewer external than internal links; however, current Bayesian models of network communities do not exert this intuitive notion of communities. We formulate a nonparametric Bayesian model...... for community detection consistent with an intuitive definition of communities and present a Markov chain Monte Carlo procedure for inferring the community structure. A Matlab toolbox with the proposed inference procedure is available for download. On synthetic and real networks, our model detects communities...... consistent with ground truth, and on real networks, it outperforms existing approaches in predicting missing links. This suggests that community structure is an important structural property of networks that should be explicitly modeled....

  8. Student Engagement with Community

    Science.gov (United States)

    Knight-McKenna, Mary; Felten, Peter; Darby, Alexa

    2018-01-01

    Student engagement in the local community comes with both risks and rewards. This chapter explains the cognitive, behavioral, and affective outcomes of student learning in the community, along with noting the importance of preparation and reflection.

  9. Unsewered Communities in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — The unsewered communities file was originally conceived as a representation of communities without a municipal sewer system or on-site septic systems. The selection...

  10. Witness, Service, and Community.

    Science.gov (United States)

    McCarthy, Kathleen Mary

    1997-01-01

    Reviews the mission of Catholic schools as defined by the church and Vatican II. Suggests that schools be responsive to their communities, implement fair policies, remain faithful to the Catholic tradition, and foster participation in the community. (JDI)

  11. Community Challenge Grantees

    Data.gov (United States)

    Department of Housing and Urban Development — HUD's Community Challenge Grants aim to reform and reduce barriers to achieving affordable, economically vital and sustainable communities. The funds are awarded to...

  12. Community Nursing Home (CNH)

    Data.gov (United States)

    Department of Veterans Affairs — The Community Nursing Home (CNH) database contains a list of all Community Nursing Home facilities under local contract to Veterans Health Administration (VHA). CNH...

  13. Knowledge Communities in fives

    NARCIS (Netherlands)

    Andriessen, J.H.E.

    2006-01-01

    Many modern knowledge intensive organisations rely on knowledge sharing communities, often called ‘communities of practice. These communities can be found in many organisations, but their forms and functions appear to be quite diverse. This implies that questions concerning the functioning of

  14. American Indian Community Colleges.

    Science.gov (United States)

    One Feather, Gerald

    With the emergence of reservation based community colleges (th Navajo Community College and the Dakota Community Colleges), the American Indian people, as decision makers in these institutions, are providing Indians with the technical skills and cultural knowledge necessary for self-determination. Confronted with limited numbers of accredited…

  15. The Learning Community.

    Science.gov (United States)

    Boo, Mary Richardson; Decker, Larry E.

    This guide to community education offers strategies and suggestions for responding to the call for more community involvement in partnership efforts that will benefit education and society. First, a brief introduction summarizes the philosophy of community education, defining it as a belief that learning is lifelong and that self-help efforts…

  16. Discourse Communities and Communities of Practice

    DEFF Research Database (Denmark)

    Pogner, Karl-Heinz

    2005-01-01

    This paper aims at giving a more detailed description and discussion of two concepts of `community' developed in the research areas of text production/ writing and social learning / information management / knowledge sharing and comparing them with each other. The purpose of this theoretical exer...... production at different Danish workplaces (a consulting engi-neering company, a university department and a bank) and discusses their significance in the context of co-located as well as geographically distrib-uted communities....

  17. Loyalty in Online Communities.

    Science.gov (United States)

    Hamilton, William L; Zhang, Justine; Danescu-Niculescu-Mizil, Cristian; Jurafsky, Dan; Leskovec, Jure

    2017-05-01

    Loyalty is an essential component of multi-community engagement. When users have the choice to engage with a variety of different communities, they often become loyal to just one, focusing on that community at the expense of others. However, it is unclear how loyalty is manifested in user behavior, or whether certain community characteristics encourage loyalty. In this paper we operationalize loyalty as a user-community relation: users loyal to a community consistently prefer it over all others; loyal communities retain their loyal users over time. By exploring a large set of Reddit communities, we reveal that loyalty is manifested in remarkably consistent behaviors. Loyal users employ language that signals collective identity and engage with more esoteric, less popular content, indicating that they may play a curational role in surfacing new material. Loyal communities have denser user-user interaction networks and lower rates of triadic closure, suggesting that community-level loyalty is associated with more cohesive interactions and less fragmentation into subgroups. We exploit these general patterns to predict future rates of loyalty. Our results show that a user's propensity to become loyal is apparent from their initial interactions with a community, suggesting that some users are intrinsically loyal from the very beginning.

  18. Mining with communities

    International Nuclear Information System (INIS)

    Veiga, Marcello M.; Scoble, Malcolm; McAllister, Mary Louise

    2001-01-01

    To be considered as sustainable, a mining community needs to adhere to the principles of ecological sustainability, economic vitality and social equity. These principles apply over a long time span, covering both the life of the mine and post-mining closure. The legacy left by a mine to the community after its closure is emerging as a significant aspect of its planning. Progress towards sustainability is made when value is added to a community with respect to these principles by the mining operation during its life cycle. This article presents a series of cases to demonstrate the diverse potential challenges to achieving a sustainable mining community. These case studies of both new and old mining communities are drawn mainly from Canada and from locations abroad where Canadian companies are now building mines. The article concludes by considering various approaches that can foster sustainable mining communities and the role of community consultation and capacity building. (author)

  19. Response of Submerged Macrophyte Communities to External and Internal Restoration Measures in North Temperate Shallow Lakes

    Science.gov (United States)

    Hilt, Sabine; Alirangues Nuñez, Marta M.; Bakker, Elisabeth S.; Blindow, Irmgard; Davidson, Thomas A.; Gillefalk, Mikael; Hansson, Lars-Anders; Janse, Jan H.; Janssen, Annette B. G.; Jeppesen, Erik; Kabus, Timm; Kelly, Andrea; Köhler, Jan; Lauridsen, Torben L.; Mooij, Wolf M.; Noordhuis, Ruurd; Phillips, Geoff; Rücker, Jacqueline; Schuster, Hans-Heinrich; Søndergaard, Martin; Teurlincx, Sven; van de Weyer, Klaus; van Donk, Ellen; Waterstraat, Arno; Willby, Nigel; Sayer, Carl D.

    2018-01-01

    Submerged macrophytes play a key role in north temperate shallow lakes by stabilizing clear-water conditions. Eutrophication has resulted in macrophyte loss and shifts to turbid conditions in many lakes. Considerable efforts have been devoted to shallow lake restoration in many countries, but long-term success depends on a stable recovery of submerged macrophytes. However, recovery patterns vary widely and remain to be fully understood. We hypothesize that reduced external nutrient loading leads to an intermediate recovery state with clear spring and turbid summer conditions similar to the pattern described for eutrophication. In contrast, lake internal restoration measures can result in transient clear-water conditions both in spring and summer and reversals to turbid conditions. Furthermore, we hypothesize that these contrasting restoration measures result in different macrophyte species composition, with added implications for seasonal dynamics due to differences in plant traits. To test these hypotheses, we analyzed data on water quality and submerged macrophytes from 49 north temperate shallow lakes that were in a turbid state and subjected to restoration measures. To study the dynamics of macrophytes during nutrient load reduction, we adapted the ecosystem model PCLake. Our survey and model simulations revealed the existence of an intermediate recovery state upon reduced external nutrient loading, characterized by spring clear-water phases and turbid summers, whereas internal lake restoration measures often resulted in clear-water conditions in spring and summer with returns to turbid conditions after some years. External and internal lake restoration measures resulted in different macrophyte communities. The intermediate recovery state following reduced nutrient loading is characterized by a few macrophyte species (mainly pondweeds) that can resist wave action allowing survival in shallow areas, germinate early in spring, have energy-rich vegetative

  20. Response of Submerged Macrophyte Communities to External and Internal Restoration Measures in North Temperate Shallow Lakes.

    Science.gov (United States)

    Hilt, Sabine; Alirangues Nuñez, Marta M; Bakker, Elisabeth S; Blindow, Irmgard; Davidson, Thomas A; Gillefalk, Mikael; Hansson, Lars-Anders; Janse, Jan H; Janssen, Annette B G; Jeppesen, Erik; Kabus, Timm; Kelly, Andrea; Köhler, Jan; Lauridsen, Torben L; Mooij, Wolf M; Noordhuis, Ruurd; Phillips, Geoff; Rücker, Jacqueline; Schuster, Hans-Heinrich; Søndergaard, Martin; Teurlincx, Sven; van de Weyer, Klaus; van Donk, Ellen; Waterstraat, Arno; Willby, Nigel; Sayer, Carl D

    2018-01-01

    Submerged macrophytes play a key role in north temperate shallow lakes by stabilizing clear-water conditions. Eutrophication has resulted in macrophyte loss and shifts to turbid conditions in many lakes. Considerable efforts have been devoted to shallow lake restoration in many countries, but long-term success depends on a stable recovery of submerged macrophytes. However, recovery patterns vary widely and remain to be fully understood. We hypothesize that reduced external nutrient loading leads to an intermediate recovery state with clear spring and turbid summer conditions similar to the pattern described for eutrophication. In contrast, lake internal restoration measures can result in transient clear-water conditions both in spring and summer and reversals to turbid conditions. Furthermore, we hypothesize that these contrasting restoration measures result in different macrophyte species composition, with added implications for seasonal dynamics due to differences in plant traits. To test these hypotheses, we analyzed data on water quality and submerged macrophytes from 49 north temperate shallow lakes that were in a turbid state and subjected to restoration measures. To study the dynamics of macrophytes during nutrient load reduction, we adapted the ecosystem model PCLake. Our survey and model simulations revealed the existence of an intermediate recovery state upon reduced external nutrient loading, characterized by spring clear-water phases and turbid summers, whereas internal lake restoration measures often resulted in clear-water conditions in spring and summer with returns to turbid conditions after some years. External and internal lake restoration measures resulted in different macrophyte communities. The intermediate recovery state following reduced nutrient loading is characterized by a few macrophyte species (mainly pondweeds) that can resist wave action allowing survival in shallow areas, germinate early in spring, have energy-rich vegetative

  1. National Community Solar Platform

    Energy Technology Data Exchange (ETDEWEB)

    Rupert, Bart [Clean Energy Collective, Louisville, CO (United States)

    2016-06-30

    This project was created to provide a National Community Solar Platform (NCSP) portal known as Community Solar Hub, that is available to any entity or individual who wants to develop community solar. This has been done by providing a comprehensive portal to make CEC’s solutions, and other proven community solar solutions, externally available for everyone to access – making the process easy through proven platforms to protect subscribers, developers and utilities. The successful completion of this project provides these tools via a web platform and integration APIs, a wide spectrum of community solar projects included in the platform, multiple groups of customers (utilities, EPCs, and advocates) using the platform to develop community solar, and open access to anyone interested in community solar. CEC’s Incubator project includes web-based informational resources, integrated systems for project information and billing systems, and engagement with customers and users by community solar experts. The combined effort externalizes much of Clean Energy Collective’s industry-leading expertise, allowing third parties to develop community solar without duplicating expensive start-up efforts. The availability of this platform creates community solar projects that are cheaper to build and cheaper to participate in, furthering the goals of DOE’s SunShot Initiative. Final SF 425 Final SF 428 Final DOE F 2050.11 Final Report Narrative

  2. Career guidance in communities

    DEFF Research Database (Denmark)

    Thomsen, Rie

    for the development of a critically reflexive career guidance practice. The considerations are organised around seven elements. 1. Creating opportunity, structure and access 2. Entering a community and increasing visibility 3. Providing guidance in communities 4. Exploring potentials in guidance situations 5...... in career guidance practices as well as in the lives of the people in the communities. This paper falls into two parts: The first part considers the collective as the starting point for the development of meaningful career guidance activities. Based on previous research on career guidance in communities......The aim of this paper is to inspire practitioners and professionals to leave their offices to bring career guidance into communities that might not identify with career guidance in the first instance. By making the effort to engage with communities, practitioners may bring about a critical change...

  3. Collaborative Communities of Firms

    DEFF Research Database (Denmark)

    2011-01-01

    and developing strategic initiatives that aid the community as a whole. We discuss the facilitator role of the shared services provider, contrasting it with the coordinator role found in other multi-firm organizations, and we show how shared services providers function by describing three examples...... is an organizational model called the collaborative community of firms. This chapter addresses an important organizational role in a collaborative community, that of the shared services provider. The shared services provider acts as a facilitator in the community, helping member firms collaborate with one another...... of collaborative communities of firms from different sectors: the U.S.-based Blade.org and two Denmark-based communities, the Kalundborg Industrial Symbiosis and MG50. Implications for the theory and practice of organization design are discussed....

  4. Interrupting Mythic Community

    Directory of Open Access Journals (Sweden)

    Linnell Secomb

    2013-09-01

    Full Text Available If nation is increasingly perceived as a less than honourable institution formed through war, invasion and geo-political territorialisation, and government is widely denounced as the site of political intrigue and the means of subjectification of citizen–voters, community appears to escape this critique and to be viewed as an idyllic formation based on bonds of affinity. However, this romancing of community is disrupted by trans-cultural and sub-cultural formations that expose the fantasy of a harmonious, homogenous community. While community is often conceived as arising organically from familial, tribal or cultural similarity, or as constituted through a common history and shared cultural institutions, this totalising conception of community is interrupted by the demands of difference and heterogeneity and by a questioning of the idyll of community authenticated in myths of archaic origin.

  5. Community impact management

    International Nuclear Information System (INIS)

    Baril, R.G.

    1983-01-01

    Industrial expansion, whether for resource extraction, refining, production or distribution and particularly the construction of energy facilities, usually has many effects on communities. In the early 1970s, as more experience was gained with large projects and as communities became more sensitive to their needs and rights, the negative effects of projects gained some prominence. Communities questioned whether it was in their best interest to accept changes that large corporations would impose on them. It is in this context that Ontario Hydro, in 1977, set up the first of four community impact agreements for the construction of generating stations. This paper discusses these community impact agreements and how they have become the framework for the management of community impacts. Also, the paper discusses a model for compensating social impacts

  6. Coal, culture and community

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-11-01

    16 papers are presented with the following titles: the miners; municipalisation and the millenium - Bolton-upon-Dearne Urban District Council 1899-1914; the traditional working class community revisited; the cultural capital of coal mining communities; activities, strike-breakers and coal communities; the limits of protest - media coverage of the Orgreave picket during the miners` strike; in defence of home and hearth? Families, friendships and feminism in mining communities; young people`s attitudes to the police in mining communities; the determinants of productivity growth in the British coal mining industry, 1976-1989; strategic responses to flexibility - a case study in coal; no coal turned in Yorkshire?; the North-South divide in the Central Coalfields; the psychological effects of redundancy and worklessness - a case study from the coalfields; the Dearne Valley initiative; the future under labour: and coal, culture and the community.

  7. From Greenland to green lakes: Cultural eutrophication and the loss of benthic pathways in lakes

    DEFF Research Database (Denmark)

    Vadeboncoeur, Y.; Jeppesen, E.; Zanden, M. J. V.

    2003-01-01

    Benthic community responses to lake eutrophication are poorly understood relative to pelagic responses. We compared phytoplankton and periphyton productivity along a eutrophication gradient in Greenland, U.S., and Danish lakes. Phytoplankton productivity increased along the phosphorus gradient (t...

  8. MBS Native Plant Communities

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data layer contains results of the Minnesota County Biological Survey (MCBS). It includes polygons representing the highest quality native plant communities...

  9. Communities running energy

    International Nuclear Information System (INIS)

    Wallace, Paula

    2014-01-01

    The conditions for the evolution of community renewable energy are right in some parts of the country. This article reports on some recent developments, with opportunities for business and local government. Many communities across Australia are developing wind and solar projects, but only a fraction are actually generating power. Nicky Ison, researcher of community renewable energy (CRE) at the Institute for Sustainable Futures, is director of the Community Power Agency. The latter is behind a new coalition lobbying the federal government in Australia to establish a $50 million grant program to support the development stage of CRE projects.

  10. Defining political community

    Directory of Open Access Journals (Sweden)

    Sladeček Michal M.

    2002-01-01

    Full Text Available This paper considers the concept of political community, its constitution and value. The starting point is that the concept of community is not sufficiently recognized in modern political theories, as well as in contemporary liberal theory. In the last two decades communitarian and republican political theory attempted to revitalize this notion. The first part of the paper elaborates on the polemics between these three theoretical orientations. The concluding part examines the possibilities and prospect for stable political community in conditions of pluralism of particular social communities and ethnocultural heterogeneity.

  11. Nuclear Community in network

    International Nuclear Information System (INIS)

    Tejedor, E.

    2014-01-01

    The internet has revolutionized the ways of communication and many companies/ organizations have adapted to the change but others have not, or have done it halfway. This presentation is a review of the main characteristics of virtual communities and their typology. The status of the Nuclear Online Community, both pro nuclear and antinuclear is analysed , and their main similarities and differences are discussed. The Pro nuclear Online Community is formed gradually. This presentation attempts to define some ways to increase the scope of the Community and encourage greater dissemination of the characteristics of nuclear energy. (Author)

  12. Water Quality Criteria for Nitroglycerin.

    Science.gov (United States)

    1986-07-01

    periphyton being dominated by a coccoid myxophycean (blue- green alga) and the phytoplankton being dominated by two species of the genus Scoedesmu...not nitrogly- cerin related . Survival of both larvae and adults of the first genera- tion was significantly (P = 0.05) reduced at concentrations of...after a 4-week colonization period. The algal community was similarly affected in the RP pond. The periphyton and phytoplakton communities were both

  13. Open source community organization

    CSIR Research Space (South Africa)

    Molefe, Onkgopotse M

    2009-05-01

    Full Text Available Open Source communities (OSCs), sometimes referred to as virtual or online communities play a significant role in terms of the contribution they continue to make in producing user-friendly Open Source Software (OSS) solutions. Many projects have...

  14. EMI New User Communities

    CERN Document Server

    Riedel, M

    2013-01-01

    This document provides pieces of information about new user communities that directly or indirectly take advantage of EMI Products. Each user community is described via one specific EMI product use case to understand and communicate the current usage of EMI Products in practice.

  15. Community as Curriculum

    Science.gov (United States)

    Cummins, Jim; Chow, Patricia; Schechter, Sandra R.

    2006-01-01

    This article describes a project involving teachers, parents, and university researchers in collaborations to support multilingual children's development and use of language. Strategies for fostering an inclusive climate included building on the interests and resources of the local community, involving community members in curriculum development,…

  16. Community Music in Australia

    Science.gov (United States)

    Harrison, Gillian

    2010-01-01

    This paper presents a historical perspective to the development of community music in Australia. Finding political support in Australia's progressive arts policies of the late 1970s, community music is discussed as embracing the principles of access and equity and supporting the development of musical skills in the context of social change and…

  17. Decoding communities in networks

    Science.gov (United States)

    Radicchi, Filippo

    2018-02-01

    According to a recent information-theoretical proposal, the problem of defining and identifying communities in networks can be interpreted as a classical communication task over a noisy channel: memberships of nodes are information bits erased by the channel, edges and nonedges in the network are parity bits introduced by the encoder but degraded through the channel, and a community identification algorithm is a decoder. The interpretation is perfectly equivalent to the one at the basis of well-known statistical inference algorithms for community detection. The only difference in the interpretation is that a noisy channel replaces a stochastic network model. However, the different perspective gives the opportunity to take advantage of the rich set of tools of coding theory to generate novel insights on the problem of community detection. In this paper, we illustrate two main applications of standard coding-theoretical methods to community detection. First, we leverage a state-of-the-art decoding technique to generate a family of quasioptimal community detection algorithms. Second and more important, we show that the Shannon's noisy-channel coding theorem can be invoked to establish a lower bound, here named as decodability bound, for the maximum amount of noise tolerable by an ideal decoder to achieve perfect detection of communities. When computed for well-established synthetic benchmarks, the decodability bound explains accurately the performance achieved by the best community detection algorithms existing on the market, telling us that only little room for their improvement is still potentially left.

  18. Caring for the community.

    Science.gov (United States)

    Spitzer, Roxane

    2004-01-01

    Nurses can play a unique role in caring for their communities. The first and most obvious role is the direct care of patients, the underlying raison d'etre of nursing, and second is the indirect care of the patients' families and friends. The hands-on healing image of nurses is held by many people and personified through the years by such real-life examples as Clara Barton. It is also the image that attracts many to nursing and is fueled by desire--the desire to help, to make a positive difference, and to serve people. It is often a powerful one-on-one connection between caregiver and receiver, nurse and patient, that defines the role of nursing. Yet, nurses can--and should--play broader roles in caring for their communities. This includes the internal community within one's own organization, the environment in which nurses work, and the larger external community--or communities--in which one lives. By reaching out and caring for the broader communities, nurses have the opportunity to grow while the communities benefit from their participatory caring. In addition, the image of nursing is enhanced externally. The nurse as community caregiver melds the heart and soul of nursing for a new 21st century model of caring.

  19. Decoding communities in networks.

    Science.gov (United States)

    Radicchi, Filippo

    2018-02-01

    According to a recent information-theoretical proposal, the problem of defining and identifying communities in networks can be interpreted as a classical communication task over a noisy channel: memberships of nodes are information bits erased by the channel, edges and nonedges in the network are parity bits introduced by the encoder but degraded through the channel, and a community identification algorithm is a decoder. The interpretation is perfectly equivalent to the one at the basis of well-known statistical inference algorithms for community detection. The only difference in the interpretation is that a noisy channel replaces a stochastic network model. However, the different perspective gives the opportunity to take advantage of the rich set of tools of coding theory to generate novel insights on the problem of community detection. In this paper, we illustrate two main applications of standard coding-theoretical methods to community detection. First, we leverage a state-of-the-art decoding technique to generate a family of quasioptimal community detection algorithms. Second and more important, we show that the Shannon's noisy-channel coding theorem can be invoked to establish a lower bound, here named as decodability bound, for the maximum amount of noise tolerable by an ideal decoder to achieve perfect detection of communities. When computed for well-established synthetic benchmarks, the decodability bound explains accurately the performance achieved by the best community detection algorithms existing on the market, telling us that only little room for their improvement is still potentially left.

  20. Community of Practice

    DEFF Research Database (Denmark)

    Busch-Jensen, Peter

    2014-01-01

    The concept of “communities of practice” is of relatively recent date. The concept gained momentum with Jean Lave and Etienne Wenger’s book from 1991, Situated learning: Legitimate peripheral participation. Since then, the notion of “communities of practice” has been a focus of attention, not least...

  1. An Enriching Community.

    Science.gov (United States)

    Holland, Nancy A.; Burroughs, Jean

    2001-01-01

    Successful school-community partnerships in Volusia (Florida) Public Schools are the results of marketing creatively, meeting community members' needs, and bringing the right people together. The 3-year old program now offers students of all ages an expanding list of enrichment classes on many subjects for a nominal fee. (MLH)

  2. Community Research Mythology

    Science.gov (United States)

    Waldern, Barbara

    2006-01-01

    This article is dedicated to an in-depth discussion of the theme community and the implications the multiple meanings of community hold for the field of qualitative research. This theme surfaced from Walderns 2003 study entitled Resistance to Research in Vancouvers Downtown Eastside, which dealt with participant resistance to joining research…

  3. Community Information Systems.

    Science.gov (United States)

    Freeman, Andrew

    Information is provided on technological and social trends as background for a workshop designed to heighten the consciousness of workers in community information systems. Initially, the basic terminology is considered in its implications for an integrated perspective of community information systems, with particular attention given to the meaning…

  4. Alaska Community Transit

    Science.gov (United States)

    Grant Information Human Services Funding 5310 5316 (Repealed) 5317 (Repealed) Alaska Mental Health Trust Department of Transportation & Public Facilities/ Alaska Community Transit Search DOT&PF State of Alaska Photo banner DOT&PF> Program Development > Alaska Community Transit Home About Us

  5. Community-Based Care

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Community-Based Care Basic Facts & Information A variety of healthcare options ... day care centers are either in churches or community centers. Adult day care is commonly used to care for people who ...

  6. Community of Practice

    DEFF Research Database (Denmark)

    Busch-Jensen, Peter

    2012-01-01

    A clear and informative description of the theoretical and methodological content and implications of the concept of Community of Practice......A clear and informative description of the theoretical and methodological content and implications of the concept of Community of Practice...

  7. Community Colleges Today

    Science.gov (United States)

    Crawford, Corinne; Jervis, Angela

    2011-01-01

    Dr. Jill Biden, Vice President Joe Biden's wife, has been teaching in community colleges for the past 18 years. Dr. Biden believes that community colleges are "…uniquely American institutions where anyone who walks through the door is one step closer to realizing the American dream." This is an inspiring sentiment. However, of all the…

  8. It Takes a Community

    Science.gov (United States)

    Jacobson, Reuben; Villarreal, Lisa; Muñoz, José; Mahaffey, Robert

    2018-01-01

    Community schools are a sound education reform strategy that gets results. They start by asking local students and their families what they need to succeed in school, then they reach out to relevant community partners and use the school as the hub for organizing partnerships, services, and supports. By listening closely to the assets and needs of…

  9. The Ethic of Community

    Science.gov (United States)

    Furman, Gail C.

    2004-01-01

    This article proposes the concept of an ethic of community to complement and extend other ethical frames used in education e.g. the ethics of justice, critique, and care. Proceeding from the traditional definition of ethics as the study of moral duty and obligation, ethic of community is defined as the moral responsibility to engage in communal…

  10. UNM in the Community.

    Science.gov (United States)

    Quantum: Research & Scholarship, 1998

    1998-01-01

    Profiles 10 University of New Mexico community programs: University Art Museum, Rio Grande and Four Corners Writing Projects, Blacks in the Southwest (exhibit), New Mexico Engineering Research Institute's Environmental Finance Center, Adolescent Social Action Program, Minority Engineering Programs, Rural Community College Initiative, Valencia…

  11. Creating Learning Communities: An Introduction to Community Education.

    Science.gov (United States)

    Decker, Larry E.; Boo, Mary Richardson

    Schools cannot succeed without collaboration with parents and the community. Defining community education as active community involvement in the education of children, this booklet describes aspects of community education. Community education, the booklet points out, can take place at physical locations such as formal school buildings, which lie…

  12. Predictability in community dynamics.

    Science.gov (United States)

    Blonder, Benjamin; Moulton, Derek E; Blois, Jessica; Enquist, Brian J; Graae, Bente J; Macias-Fauria, Marc; McGill, Brian; Nogué, Sandra; Ordonez, Alejandro; Sandel, Brody; Svenning, Jens-Christian

    2017-03-01

    The coupling between community composition and climate change spans a gradient from no lags to strong lags. The no-lag hypothesis is the foundation of many ecophysiological models, correlative species distribution modelling and climate reconstruction approaches. Simple lag hypotheses have become prominent in disequilibrium ecology, proposing that communities track climate change following a fixed function or with a time delay. However, more complex dynamics are possible and may lead to memory effects and alternate unstable states. We develop graphical and analytic methods for assessing these scenarios and show that these dynamics can appear in even simple models. The overall implications are that (1) complex community dynamics may be common and (2) detailed knowledge of past climate change and community states will often be necessary yet sometimes insufficient to make predictions of a community's future state. © 2017 John Wiley & Sons Ltd/CNRS.

  13. [Community marketing of contraceptives].

    Science.gov (United States)

    Urrutia, J M

    1987-09-01

    The 5-year-old community contraceptive distribution program developed by PROFAMILIA, Colombia's private family planning organization, has given excellent results, but several cost-effectiveness comparisons with social marketing programs have suggested that commercial distribution programs are superior. The community contraceptive distribution program has a high content of information and education activities, which produced significant increases in knowledge and use of contraception in the communities covered. It has been a fundamental support for the social marketing program, creating much of the demand for contraceptive products that the social marketing program has filled. The social marketing program has given good results in terms of volume of sales and in cost-effectiveness since 1976, prompting calls for replacement of the community contraceptive distribution program by the social marketing program in those sectors where knowledge and use of contraception have achieved acceptable levels. An experiment in the Department of Santander in 1984 and 1985 gave very favorable results, suggesting that community contraceptive distribution programs should be replaced by social marketing programs in all more developed markets. But economic problems in 1985 and the decision of manufacturers to decrease the profit margin for PROFAMILIA jeopardized the social marketing program. The community distribution program covered about 20% of the market. Reduced profits in the social marketing program threatened its continued expansion, at the same time that potential demand was growing because of increases in the fertile aged population and increased use of contraception. To meet the need, PROFAMILIA combined the community contraceptive distribution and social marketing programs into a new entity to be called community marketing. The strategy of the community marketing program will be to maintain PROFAMILIA's participation in the market and aid the growth of demand for

  14. Building global learning communities

    Directory of Open Access Journals (Sweden)

    Averill Gordon

    2013-09-01

    Full Text Available Within the background where education is increasingly driven by the economies of scale and research funding, we propose an alternative online open and connected framework (OOC for building global learning communities using mobile social media. We critique a three year action research case study involving building collaborative global learning communities around a community of practice of learning researchers and practitioners. The results include the development of a framework for utilising mobile social media to support collaborative curriculum development across international boundaries. We conclude that this framework is potentially transferrable to a range of educational contexts where the focus is upon student-generated mobile social media projects.

  15. Collaborative Communities of Firms

    DEFF Research Database (Denmark)

    Bøllingtoft, Anne; Müller, Sabine; Ulhøi, John Parm

    2011-01-01

    and developing strategic initiatives that aid the community as a whole. We discuss the facilitator role of the shared services provider, contrasting it with the coordinator role found in other multi-firm organizations, and we show how shared services providers function by describing three examples...... of collaborative communities of firms from different sectors: the U.S.-based Blade.org and two Denmark-based communities, the Kalundborg Industrial Symbiosis and MG50. Implications for the theory and practice of organization design are discussed....

  16. [(Community) psychiatry, a parenthesis?].

    Science.gov (United States)

    Bucheron, Bastien

    2015-01-01

    Beyond an a priori antagonism between these two notions, alienism and mental health cultivate analogies as to the place to which they assign mental health. Is community psychiatry not therefore simply a parenthesis in the history of psychiatry? The question is raised therefore regarding the place given to subjectivity and complexity. What must be done to ensure that this parenthesis of community psychiatry does not close? It is perhaps a case of making use of the tools which institutional psychotherapy has developed to keep the community psychiatry spirit alive. Copyright © 2015. Published by Elsevier Masson SAS.

  17. The European Community context

    International Nuclear Information System (INIS)

    Charrault, J.C.

    1984-01-01

    The chapter discusses the following: energy resources and energy policy within the European Community; political aspects in the Member States; Community involvement in the transport of radioactive materials; responsibility for safety in relation to transport lies with the governments of the Member States, but the Community through its various organizations also has certain responsibilities, e.g. to ensure that transport regulations are harmonised, to carry out safeguards checks, to provide standards for health and safety of workers and the public, and to cooperate with Member States in developing guidelines for transport safety. (U.K.)

  18. Assessing Community Informatics: A Review of Methodological Approaches for Evaluating Community Networks and Community Technology Centers.

    Science.gov (United States)

    O'Neil, Dara

    2002-01-01

    Analyzes the emerging community informatics evaluation literature to develop an understanding of the indicators used to gauge project impacts in community networks and community technology centers. The study finds that community networks and community technology center assessments fall into five key areas: strong democracy; social capital;…

  19. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    user

    2Department of Community Health, University of Benin, Benin City, Nigeria. ... Mental morbidity is a public health problem that can lead to a great burden of disability in the community. ..... community study in Sao Paulo, Brazil where.

  20. Engaging the Community

    CSIR Research Space (South Africa)

    Jacobs-Mata, Inga M

    2011-03-01

    Full Text Available Claassen observes, "There is an interesting co-existence of traditional culture and modern ideas and also "African" religion and Christianity. Traditional leaders and community members were very open and most helpful in the research." Photos: Photo...

  1. Cleanups in My Community

    Data.gov (United States)

    U.S. Environmental Protection Agency — Cleanups in My Community (CIMC) is a public web application that enables integrated access through maps, lists and search filtering to site-specific information EPA...

  2. Police Community Outreach

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Community outreach activities attended by Pittsburgh Police Officers, starting from January 1 2016. Includes Zone, Event Name, Location, Date and Time.

  3. FEMA DFIRM Community Info

    Data.gov (United States)

    Minnesota Department of Natural Resources — This table is a lookup table that contains community map repository details and map history information that is shown on the Flood Insurance Rate Map (FIRM) legend...

  4. Green Power Communities

    Science.gov (United States)

    GPCs are towns, villages, cities, counties, or tribal governments in which the local government, businesses, and residents collectively use green power in amounts that meet or exceed EPA's Green Power Community purchase requirements.

  5. Online Community Transition Detection

    DEFF Research Database (Denmark)

    Tan, Biying; Zhu, Feida; Qu, Qiang

    2014-01-01

    communities over time. How to automatically detect the online community transitions of individual users is a research problem of immense practical value yet with great technical challenges. In this paper, we propose an algorithm based on the Minimum Description Length (MDL) principle to trace the evolution......Mining user behavior patterns in social networks is of great importance in user behavior analysis, targeted marketing, churn prediction and other applications. However, less effort has been made to study the evolution of user behavior in social communities. In particular, users join and leave...... of community transition of individual users, adaptive to the noisy behavior. Experiments on real data sets demonstrate the efficiency and effectiveness of our proposed method....

  6. 2015 Community Survey Data

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — These are the answers to the 2015 Community Survey.A comprehensive summary of the survey results can be found here.The survey asked town members to address their...

  7. Small Community Training & Education

    Science.gov (United States)

    Operators Small Systems Small Community Training & Education education, training and professional implement the 1996 Amendments to the Safe Drinking Water Act (SDWA). • EPA Environmental Education Center

  8. Pneumonia - children - community acquired

    Science.gov (United States)

    Bronchopneumonia - children; Community-acquired pneumonia - children; CAP - children ... Viruses are the most common cause of pneumonia in infants and children. Ways your child can get CAP include: Bacteria and viruses living in the nose, sinuses, or mouth may spread ...

  9. RAS Initiative - Community Outreach

    Science.gov (United States)

    Through community and technical collaborations, workshops and symposia, and the distribution of reference reagents, the RAS Initiative seeks to increase the sharing of knowledge and resources essential to defeating cancers caused by mutant RAS genes.

  10. Fishing Community Profiles

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To enable fisheries managers to comply with National Standard 8 (NS8), NMFS social scientists around the nation are preparing fishing community profiles that present...

  11. Taskable Reactive Agent Communities

    National Research Council Canada - National Science Library

    Myers, Karen

    2002-01-01

    The focus of Taskable Reactive Agent Communities (TRAC) project was to develop mixed-initiative technology to enable humans to supervise and manage teams of agents as they perform tasks in dynamic environments...

  12. Assessing Community Telecentres

    International Development Research Centre (IDRC) Digital Library (Canada)

    the impacts of telecentres on their programs, such as youth employment or ..... the community's satisfaction with its performance (see Table 10), and basic ..... The result (average rural income) is compared with the estimated capital cost of ...

  13. Community Points of Interest

    Data.gov (United States)

    Town of Cary, North Carolina — View locations of Cary’s community centers, fire, police and EMS stations, hospitals, libraries, Cary Convenience Center, schools and post offices. Note commercial...

  14. Mobilizing community energy

    International Nuclear Information System (INIS)

    Bomberg, Elizabeth; McEwen, Nicola

    2012-01-01

    What explains the galvanising of communities to participate actively in energy projects? How do groups mobilize to overcome the often formidable barriers highlighted in the existing literature? Drawing on original qualitative research of 100 community energy groups in Scotland, including six in-depth case studies, we explain how effective mobilization occurs and the political dynamics surrounding such mobilization. To capture these dynamics, we adapt theories offered by literature on social movements, with a particular focus on resource mobilization theories. Applying our adapted framework, we identify two particular sets of resources shaping community energy mobilization: (i) structural resources, which refer to the broad political context structuring and constraining opportunities for community energy mobilization; and (ii) symbolic resources—less tangible resources used to galvanise participants. We investigate to what extent our case study groups were able to draw upon and exploit these resources. We find that structural resources can either facilitate or hinder mobilization; what matters is how state resources are exploited and constraints mitigated. The use of symbolic resources was highly effective in aiding mobilization. Each of the groups examined – despite their considerable variation – effectively exploited symbolic resources such as shared identity or desire for strong, self reliant communities. - Highlights: ► Explains how/why community energy groups mobilize and the political dynamics surrounding it. ► Draws on original qualitative research of 100 community energy groups in Scotland. ► Identifies two particular sets of resources (structural and symbolic) and their importance. ► Explains how these resources shape community energy mobilization in Scotland. ► Provides an original application of resource mobilization theory to the field of energy studies.

  15. Designing for Communities

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    In 2008, Mark Boulton's small design firm won the project to redesign drupal.org home to the Drupal open source content management project and its community of over 400,000 users and developers. Designing for open source communities has its challenges: it is a developer-centric environment where discussion, debate and consensus rules and where design processes are often viewed sceptically. To help dispel some misconceptions behind the design process, Mark's team worked completely openly with the Drupal community - and broader the web design community - throughout the project. This talk will walk through some of the challenges and solutions for designing for large communities. Mark will share the successes - and the horror stories - of how a traditional design process was challenged every step of the way and how the Drupal community became an integral part of that new process. Mark and his team will be working with the Communication Group on an open project to r...

  16. Creating one planet communities

    International Nuclear Information System (INIS)

    Wilts, R.

    2010-01-01

    This presentation discussed low carbon communities that used a variety of sustainable energy technologies to reduce energy consumption and waste. The presentation was given by a company who has adopted a One Planet framework to ensure the development of zero carbon, zero waste, sustainable communities.The Dockside Green project was awarded North America's highest leadership in energy and environmental design (LEED) score. The community includes a waste biomass plant and an on-site wastewater treatment plant. Excess heat produced by the community's greenhouse gas (GHG) neutral biomass district heating system is sold to neighbouring communities. The BedZED project in the United Kingdom uses a high-density format to support a community living and workspace environment that uses rainwater harvesting, passive solar heating, high performance envelopes, and green roofs. The site includes 40 electric car charging stations. A combined heat and power (CHP) biomass plant provides electricity and hot water to all buildings. Neighbourhood-scale sustainable development is expected to have a significant impact on the ecological footprint of North American cities. Carbon neutral projects in Canada were also listed. tabs., figs.

  17. Community Involvement in School: Social Relationships in a Bedroom Community

    Science.gov (United States)

    Preston, Jane P.

    2013-01-01

    The purpose of this qualitative case study was to describe how community involvement in school is associated with the social relationships existing/lacking within a bedroom community. Thirty-five interviews with school council members, teachers, and community members highlighted that traditional forms of community involvement in school generate…

  18. Observation of online communities

    DEFF Research Database (Denmark)

    Nørskov, Sladjana V.; Rask, Morten

    2011-01-01

    This paper addresses the application of observation to online settings with a special focus on observer roles. It draws on a study of online observation of a virtual community, i.e. an open source software (OSS) community. The paper examines general and specific advantages and disadvantages...... of the observer roles in online settings by relating these roles to the same roles assumed in offline settings. The study suggests that under the right circumstances online and offline observation may benefit from being combined as they complement each other well. Quality issues and factors important to elicit...... trustworthy observational data from online study settings, such as OSS communities, are discussed. A proposition is made concerning how threats to credibility and transferability in relation to online observation (i.e. lack of richness and detail, risk of misunderstandings) can be diminished, while...

  19. Athena Community Office

    Science.gov (United States)

    Martínez-Núnez, S.; Barcons, X.; Barret, D.; Bozzo, E.; Carrera, F. J.; Ceballos, M. T.; Gómez, S.; Monterde, M. P.; Rau, A.

    2017-03-01

    The Athena Community Office (ACO) has been established by ESA's Athena Science Study Team (ASST) in order to obtain support in performing its tasks assigned by ESA, and most specially in the ASST role as "focal point for the interests of the broad scientific community". The ACO is led by the Instituto de Física de Cantabria (CSIC-UC), and its activities are funded by CSIC and UC. Further ACO contributors are the University of Geneva, MPE and IRAP. In this poster, we present ACO to the Spanish Astronomical Community, informing about its main responsibilities, which are: assist the ASST in organising and collecting support from the Athena Working Groups and Topical Panels; organise and maintain the documentation generated by the Athena Working Groups and Topical Panels; manage the Working Group and Topical Panel membership lists; assist the ASST in promoting Athena science capabilities in the research world, through conferences and workshops; keep a record of all papers and presentations related to Athena; support the production of ASST documents; produce and distribute regularly an Athena Newsletter, informing the community about all mission and science developments; create and maintain the Athena Community web portal; maintain an active communication activity; promote, organise and support Athena science-related public outreach, in coordination with ESA and other agencies involved when appropriate; and, design, produce materials and provide pointers to available materials produced by other parties. In summary, ACO is meant to become a focal point to facilitate the scientific exchange between the Athena activities and the scientific community at large, and to disseminate the Athena science objectives to the general public.

  20. Marketing of the online communities

    OpenAIRE

    Pražan, Jan

    2010-01-01

    The Bachelor Thesis "Marketing of the online communities" is devoted to online virtual communities, one of the phenomena of the current Internet. Goal of this thesis is to determine the factors that predispose the successful operation of online communities. The thesis defines the essentials features of social media, characterized by online communities and their role in marketing. It deals with strategic and tactical aspects of building and maintaining successful online communities. Based on t...

  1. Welfare Landscape and Communities

    DEFF Research Database (Denmark)

    Braae, Ellen Marie

    2017-01-01

    Danish housing developments of the post-war era were a cornerstone in the implementation of the welfare vision and the overall urban and landscape planning in the post-war period. The new city was a horizontal city and – as it will be my primary ambition to show – a green and landscape-like city....... The landscape came, in Denmark, to play a prominent role and became synonymous with ‘The Good Life’, but it also presented a number of moral imperatives. The article concerns how communities and community feelings found their expression in the Danish ‘welfare landscapes’....

  2. The Community of Rights

    DEFF Research Database (Denmark)

    Kjærgård, Jonas Ross

    2012-01-01

    be used in a particularistic and excluding way which was the case in the legislation of Maximilien de Robespierre’s Terror Regime. Situated somewhere between inclusion in and exclusion from the community of rights, the playwright and political activist Olympe de Gouges sought to propagate an understanding...... of the natural that could better accommodate women and nonmarital children. Her attempts were futile, however, and in 1793 she was sentenced to death according to a newly written law meant to prosecute enemies of the Republic’s natural community....

  3. Community gardens: lessons learned from California Healthy Cities and Communities.

    Science.gov (United States)

    Twiss, Joan; Dickinson, Joy; Duma, Shirley; Kleinman, Tanya; Paulsen, Heather; Rilveria, Liz

    2003-09-01

    Community gardens enhance nutrition and physical activity and promote the role of public health in improving quality of life. Opportunities to organize around other issues and build social capital also emerge through community gardens. California Healthy Cities and Communities (CHCC) promotes an inclusionary and systems approach to improving community health. CHCC has funded community-based nutrition and physical activity programs in several cities. Successful community gardens were developed by many cities incorporating local leadership and resources, volunteers and community partners, and skills-building opportunities for participants. Through community garden initiatives, cities have enacted policies for interim land and complimentary water use, improved access to produce, elevated public consciousness about public health, created culturally appropriate educational and training materials, and strengthened community building skills.

  4. Celebrating indigenous communities compassionate traditions.

    Science.gov (United States)

    Prince, Holly

    2018-01-01

    Living in a compassionate community is not a new practice in First Nations communities; they have always recognized dying as a social experience. First Nations hold extensive traditional knowledge and have community-based practices to support the personal, familial, and community experiences surrounding end-of-life. However, western health systems were imposed and typically did not support these social and cultural practices at end of life. In fact, the different expectations of western medicine and the community related to end of life care has created stress and misunderstanding for both. One solution is for First Nations communities to develop palliative care programs so that people can receive care at home amongst their family, community and culture. Our research project "Improving End-of-Life Care in First Nations Communities" (EOLFN) was funded by the Canadian Institutes of Health Research [2010-2015] and was conducted in partnership with four First Nations communities in Canada (see www.eolfn.lakeheadu.ca). Results included a community capacity development approach to support Indigenous models of care at end-of-life. The workshop will describe the community capacity development process used to develop palliative care programs in First Nations communities. It will highlight the foundation to this approach, namely, grounding the program in community values and principles, rooted in individual, family, community and culture. Two First Nations communities will share stories about their experiences developing their own palliative care programs, which celebrated cultural capacity in their communities while enhancing medical palliative care services in a way that respected and integrated with their community cultural practices. This workshop shares the experiences of two First Nations communities who developed palliative care programs by building upon community culture, values and principles. The underlying model guiding development is shared.

  5. The Community College Option

    Science.gov (United States)

    Rosenbaum, James E.; Ahearn, Caitlin; Rosenbaum, Janet

    2016-01-01

    Efforts to promote college for all for all has opened college doors to a broad range of students. But college--and career success after college--doesn't have to mean a bachelor's degree. Community college credentials, such as associate's degrees and one-year certificates, can lead to further degrees or jobs that offer more benefits than students…

  6. Emerging Communities of Practice

    Science.gov (United States)

    McAlister, Martha

    2016-01-01

    Communities of practice are emerging as an innovative approach to faculty development. While collaborative learning is becoming popular in the classroom, autonomy and individualism continue to dominate the culture of higher education for faculty. However, as we begin to recognize that old solutions to new problems are no longer effective, there is…

  7. Social Innovation Communities

    Science.gov (United States)

    Satrustegui, Alfonso Unceta; Castro-Spila, Javier; Luna, Alvaro

    2017-01-01

    The concepts of hybridity and governance have been an important line of research in the context of social companies and public institutions. The purpose of this paper is to explore these notions in the framework of hybrid communities of social innovation by showing the importance of intangible capital in the improvement of functional skills,…

  8. No Community Left Behind

    Science.gov (United States)

    Schlechty, Phillip C.

    2008-01-01

    The debate over the reauthorization of No Child Left Behind (NCLB) generally overlooks--or looks past--what may be the most fundamental flaw in that legislation. As the law is now written, decisions regarding what the young should know and be able to do are removed from the hands of parents and local community leaders and turned over to officials…

  9. Violence and Community Capabilities:

    International Development Research Centre (IDRC) Digital Library (Canada)

    ous cities boast community-based initiatives that significantly reduce the ..... account the ambiguous yet critical role that gangs can play at the local level. .... promote and exercise other forms of violence, such as extortion, sexual abuse, and ... of employment that comes without any rights or protection, and making informal.

  10. Joining the Global Community.

    Science.gov (United States)

    Cawley, John; Knoester, Jocelyn

    2002-01-01

    Canada World Youth enables young Canadians to live in another part of Canada with youths from a developing country for several months while volunteering in community projects. Then they move as a group to the partner country for several months where the program structure is the same. Participants acquire the skills and values necessary to…

  11. Participatory academic communities

    DEFF Research Database (Denmark)

    Aaen, Janus Holst; Nørgård, Rikke Toft

    2015-01-01

    understanding of participation in edu-cation can move educatees’ learning beyond institutions through focusing on educatees as researchers, participat-ing in society, building a research community and obtaining academic citizenship. Further, the article discusses how a value-based, vision-driven approach...

  12. BNFL and community relations

    International Nuclear Information System (INIS)

    Bolter, H.

    1982-01-01

    The contributions made by BNFL to community relations are described in an illustrated booklet under the headings: introduction (general policy); donations and sponsorships; BNFL talks service; brochures and public information; visits; local liaison committees; industrial training; sponsored students; apprentices. (U.K.)

  13. Building Global Learning Communities

    Science.gov (United States)

    Cochrane, Thomas; Buchem, Ilona; Camacho, Mar; Cronin, Catherine; Gordon, Averill; Keegan, Helen

    2013-01-01

    Within the background where education is increasingly driven by the economies of scale and research funding, we propose an alternative online open and connected framework (OOC) for building global learning communities using mobile social media. We critique a three year action research case study involving building collaborative global learning…

  14. For Community Sake

    Science.gov (United States)

    Dunn, Jeffery W.

    2013-01-01

    This article examines whether religious education plays a role in the promotion of harmonious international relations, arguing that a broad religious education with a dialogical approach goes to the heart of what it means to be a citizen in a global community. Christian theologian Hans Kung argues in his book "Judaism: Between Yesterday and…

  15. One Community Working Together

    Science.gov (United States)

    Weis, Charles

    2011-01-01

    In the city of San Jose, more than half of all public school students tested are not proficient in their grade-level skills. This article discusses how school, civic and community leaders have joined forces with the goal of eliminating the achievement gap in San Jose by 2020. This wide and highly inclusive collaboration is made possible by an…

  16. Community Radiation Monitoring Program

    International Nuclear Information System (INIS)

    Cooper, E.N.

    1993-05-01

    The Community Radiation Monitoring Program (CRMP) is a cooperative effort between the US Department of Energy (DOE); the US Environmental Protection Agency (EPA); the Desert Research Institute (DRI), a division of the University and Community College System of Nevada and the Nuclear Engineering Laboratory of the University of Utah (UNEL). The twelfth year of the program began in the fall of 1991, and the work continues as an integral part of the DOE-sponsored long-term offsite radiological monitoring effort that has been conducted by EPA and its predecessors since the inception of nuclear testing at the Nevada Test Site (NTS). The program began as an outgrowth of activities that occurred during the Three Mile Island incident in 1979. The local interest and public participation that took place there were thought to be transferrable to the situation at the NTS, so, with adaptations, that methodology was implemented for this program. The CRMP began by enhancing and centralizing environmental monitoring and sampling equipment at 15 communities in the existing EPA monitoring network, and has since expanded to 19 locations in Nevada, Utah and California. The primary objectives of this program are still to increase the understanding by the people who live in the area surrounding the NTS of the activities for which DOE is responsible, to enhance the performance of radiological sampling and monitoring, and to inform all concerned of the results of these efforts. One of the primary methods used to improve the communication link with people in the potentially impacted area has been the hiring and training of local citizens as station managers and program representatives in those selected communities in the offsite area. These managers, active science teachers wherever possible, have succeeded, through their training, experience, community standing, and effort, in becoming a very visible, able and valuable asset in this link

  17. Leveraging disjoint communities for detecting overlapping community structure

    International Nuclear Information System (INIS)

    Chakraborty, Tanmoy

    2015-01-01

    Network communities represent mesoscopic structure for understanding the organization of real-world networks, where nodes often belong to multiple communities and form overlapping community structure in the network. Due to non-triviality in finding the exact boundary of such overlapping communities, this problem has become challenging, and therefore huge effort has been devoted to detect overlapping communities from the network.In this paper, we present PVOC (Permanence based Vertex-replication algorithm for Overlapping Community detection), a two-stage framework to detect overlapping community structure. We build on a novel observation that non-overlapping community structure detected by a standard disjoint community detection algorithm from a network has high resemblance with its actual overlapping community structure, except the overlapping part. Based on this observation, we posit that there is perhaps no need of building yet another overlapping community finding algorithm; but one can efficiently manipulate the output of any existing disjoint community finding algorithm to obtain the required overlapping structure. We propose a new post-processing technique that by combining with any existing disjoint community detection algorithm, can suitably process each vertex using a new vertex-based metric, called permanence, and thereby finds out overlapping candidates with their community memberships. Experimental results on both synthetic and large real-world networks show that PVOC significantly outperforms six state-of-the-art overlapping community detection algorithms in terms of high similarity of the output with the ground-truth structure. Thus our framework not only finds meaningful overlapping communities from the network, but also allows us to put an end to the constant effort of building yet another overlapping community detection algorithm. (paper)

  18. Handling Pressures of Community Logic

    DEFF Research Database (Denmark)

    Minbaeva, Dana; Hotho, Jasper; Muratbekova-Touron, Maral

    2013-01-01

    The paper aims at investigating how in pluralistic societies, such as emerging economies and countries in transition, organizational decision-makers respond to pressures of community logics in non-community settings, such as the work place. We theorize that in non-community settings, social...... relations and interactions with community members can act as social cues that induce and expose individuals to community logics. We subsequently propose that properties of these relations – immediacy and relatedness - will affect individual response strategies towards community logics. We test these ideas...... with an experimental vignette study of the effects of clan and kinship ties on recruitment and selection decisions in Kazakhstan, followed by qualitative interviews....

  19. Community Cookbooks: Sponsors of Literacy and Community Identity

    Science.gov (United States)

    Mastrangelo, Lisa

    2015-01-01

    This article looks at the various ways that communities can be "read" through their cookbooks. Recipes and collections can reveal much about communities, including shared memories/traditions, geographical identifications, and representations of class.

  20. Community Satisfaction in Czech Rural Communities: A Multilevel Model

    Czech Academy of Sciences Publication Activity Database

    Bernard, Josef

    2015-01-01

    Roč. 55, č. 2 (2015), s. 205-226 ISSN 0038-0199 Institutional support: RVO:68378025 Keywords : community satisfaction * rural communities * contextual effects Subject RIV: AO - Sociology , Demography Impact factor: 1.380, year: 2015

  1. Renewal strategy and community based organisations in community ...

    African Journals Online (AJOL)

    Renewal strategy and community based organisations in community ... the local population and resources to do that which the governments had failed to do. ... country with a view to reducing poverty and developmental imbalance in Nigeria.

  2. Community Solar Value Project

    Energy Technology Data Exchange (ETDEWEB)

    Powers, John T [Extensible Energy; Cliburn, Jill [Cliburn and Associates

    2017-11-30

    The Community Solar Value Project (CSVP) is designed to assist electric utilities in designing better community solar programs. Better programs seek new sources of value to promote “win-win” solutions between utilities and their customers. The CSVP focused on five “challenge areas” in identifying new sources of value: - Strategic solar design for community solar projects (including technology choices, siting, orientation, and related issues) - Market research and targeted marketing approaches (for program design and for customer recruitment) - Procurement and financing (for establishing best practices that can bring economies of scale and economies of expertise) - Integration of “companion measures” (such as storage and demand-response options that can benefit customer and utility net load shapes) - Pricing in program design (including best practices for integration of identified value in program prices or credits) The CSVP directly engaged the Sacramento Municipal Utility District (SMUD), the Public Service Company of New Mexico (PNM), and more than a dozen other utilities to develop improved community solar program designs. The outcomes include a plan at SMUD for over 100 MW or more of community and shared solar and support for new or expanded programs at 15 other utilities so far. Resulting best-practice solutions have not only informed program applications, but also have generated discussion among experts and industry associations about the new opportunities and challenges CSVP has brought forth. In these ways, the CSVP has impacted community solar programs and DER plans, competitive innovations and policies nationwide. The CSVP team has been led by Extensible Energy under John Powers, President and CEO. Jill Cliburn, of Santa Fe, NM-based Cliburn and Associates, has served as Principal Investigator. The team also benefitted from expertise from Navigant, Olivine Inc. and Millennium Energy, LLC, in addition to the collaborative and cost

  3. Community interventions for cardiovascular disease.

    Science.gov (United States)

    Parker, Donna R; Assaf, Annlouise R

    2005-12-01

    Review of the community-based CVD intervention programs suggests that a number of components have been successful using varying methods and materials for CVD risk reduction. It should be noted, however, that in multi-intervention programs it is often difficult to determine which components of the intervention were responsible for the overall success of the study. The community-based approach to CVD prevention is generalizable, cost-effective (because of the use of mass communication methods), and has the potential for modifying the environment and influencing health policies. Based on the experiences and successes of a number of community projects, recommendations have been proposed for developing future programs. Although they are not totally comprehensive, it has been suggested that a community-based intervention program should consider the following recommendations: 1) An understanding of the community: the needs and priorities of the community should be assessed, and close collaboration with individuals from the community, including community leaders, opinion leaders, community health care providers, and community organizations from various sectors of the community, should be consulted. Efforts should be focused on underserved and vulnerable populations. 2) Inclusion of community activities: these activities should be integrated within the context of the community environment, including primary health care services, voluntary organizations, grocery stores, restaurants, work sites, schools, and local media. 3) Inclusion mass media messages: the mass media can provide information and reinforcement of the behavior change. 4) Develop cost-effective interventions to assure that the community is exposed to an effective dose of the intervention. 5) Work with community organizations to help change social and physical environments to make them more conducive to health and healthy life-styles changes. 6) Develop a reliable monitoring and evaluation system: monitor the

  4. Evaluating Community Partnerships Addressing Community Resilience in Los Angeles, California

    Directory of Open Access Journals (Sweden)

    Malcolm V. Williams

    2018-03-01

    Full Text Available Community resilience has grown in importance in national disaster response and recovery efforts. However, measurement of community resilience, particularly the content and quality of relationships aimed at improving resilience, is lacking. To address this gap, we used a social network survey to measure the number, type, and quality of relationships among organizations participating in 16 coalitions brought together to address community resilience in the Los Angeles Community Disaster Resilience project. These coalitions were randomized to one of two approaches (community resilience or preparedness. Resilience coalitions received training and support to develop these partnerships and implement new activities. Both coalition types received expert facilitation by a public health nurse or community educator. We also measured the activities each coalition engaged in and the extent to which partners participated in these activities at two time points. We found that the community resilience coalitions were initially larger and had lower trust among members than the preparedness communities. Over time, these trust differences dissipated. While both coalitions grew, the resilience community coalitions maintained their size difference throughout the project. We also found differences in the types of activities implemented by the resilience communities; these differences were directly related to the trainings provided. This information is useful to organizations seeking guidance on expanding the network of community-based organizations that participate in community resilience activities.

  5. IT User Community Survey

    CERN Document Server

    Peter Jones (IT-CDA-WF)

    2016-01-01

    IT-CDA is gathering information to more accurately form a snapshot of the CERN IT user community and we would appreciate you taking time to complete the following survey.   We want to use this survey to better understand how the user community uses their devices and our services, and how the delivery of those services could be improved. You will need to authenticate to complete the survey. However please note that your responses are confidential and will be compiled together and analysed as a group. You can also volunteer to offer additional information if you so wish. This survey should take no longer than 5 minutes. Thanks in advance for your collaboration.

  6. [Identification of community leaders].

    Science.gov (United States)

    Chevalier, S; Dedobbeleer, N; Tremblay, M

    1995-01-01

    Although many methods of measuring leadership have been developed in sociological studies, there are few articles on the feasibility of these methods. The goal of this study was to verify the feasibility of the "modified positional-reputational approach" developed by Nix. The study was conducted in a small community located north of Montreal. Nix's questionnaire was translated, adapted and administered to 49 key informants. Two hundred and fourteen leaders were selected. Three types of leaders were identified: the legitimizers, the effectors and the activists. Through a sociometric analysis, we established links between the different leaders and we described the power structure of the community. Despite a few shortcomings, Nix's approach was found extremely useful.

  7. Community-acquired pneumonia.

    Science.gov (United States)

    Falguera, M; Ramírez, M F

    2015-11-01

    This article not only reviews the essential aspects of community-acquired pneumonia for daily clinical practice, but also highlights the controversial issues and provides the newest available information. Community-acquired pneumonia is considered in a broad sense, without excluding certain variants that, in recent years, a number of authors have managed to delineate, such as healthcare-associated pneumonia. The latter form is nothing more than the same disease that affects more frail patients, with a greater number of risk factors, both sharing an overall common approach. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  8. A Professional Learning Community Journey

    Directory of Open Access Journals (Sweden)

    Diana Maliszewski

    2008-06-01

    Full Text Available Four teachers (three classroom teachers and a teacher-librarian explain how their school applied a professional learning community framework to its operational practices. They discuss the process, the benefits, and the challenges of professional learning communities.

  9. Service Station for the Community

    Science.gov (United States)

    Fulk, Margaret E.; Blank, Gordon C.

    1977-01-01

    Western Piedmont Community College adopted the concept of a people-oriented Learning Resources Center with services offered to the entire college community through a learning laboratory, audiovisual center and library. (JG)

  10. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    Background:Community Based Health Insurance Scheme is a social service organized at community level. It is a mutual health ... As part of her corporate social responsibility. Shell in .... Schmidt J. The benefits and challenges of shows the ...

  11. Community Resources and Job Placement

    Science.gov (United States)

    Preston, Jim

    1977-01-01

    In cooperation with the chamber of commerce, various businesses, associations, and other community agencies, the Sarasota schools (Florida) supplement their own job placement and follow-up efforts with community job development strategies for placing high school graduates. (JT)

  12. Mapping earthworm communities in Europe

    NARCIS (Netherlands)

    Rutgers, M.; Orgiazzi, A.; Gardi, C.; Römbke, J.; Jansch, S.; Keith, A.; Neilson, R.; Boag, B.; Schmidt, O.; Murchie, A.K.; Blackshaw, R.P.; Pérès, G.; Cluzeau, D.; Guernion, M.; Briones, M.J.I.; Rodeiro, J.; Pineiro, R.; Diaz Cosin, D.J.; Sousa, J.P.; Suhadolc, M.; Kos, I.; Krogh, P.H.; Faber, J.H.; Mulder, C.; Bogte, J.J.; Wijnen, van H.J.; Schouten, A.J.; Zwart, de D.

    2016-01-01

    Existing data sets on earthworm communities in Europe were collected, harmonized, collated, modelled and depicted on a soil biodiversity map. Digital Soil Mapping was applied using multiple regressions relating relatively low density earthworm community data to soil characteristics, land use,

  13. The invertebrate communities

    International Nuclear Information System (INIS)

    FloBner, D.; Kasprzak, P.; Mothes, G.; Ronneberger, D.; Schonborn, W.

    1985-01-01

    Studies of invertebrate communities have been carried out to a certain extent in the whole Lake Stechlin area, but especially with reference to Lake Stechlin. The chapter summarizes important results of detailed investigations over a long period, made by several researchers in the periods before and after the nuclear power plant came into operation. The following sections deal with the combination of species, frequency, types of life-form, structure and dynamics of the living community of zoobenthos and zooplankton. Not dealt with or only considered in passing are Amoebina, Heliozoa, Ciliata, Turbellaria (excl. Tricladida), Nematoda, Tardigrada, Gastrotricha, and partly Oligochaeta. The research into micro-and meiooobenthos are limited to the years 1959-1968. Data after the bringing into operation of the nuclear power plant refer only to macrozoobenthos. Before the operation of the nuclear power plant the planktonic Rotaroria and Crustacea were examined only qualitatively. The first quantitative analysis of the zooplankton-community was undertaken in 1968, and only from 1978 onwards has continuous and comprehensive research information about the zooplankton in Lake Stechlin been available

  14. Community Radiation Monitoring Program

    International Nuclear Information System (INIS)

    Lucas, R.P. Jr.; Cooper, E.N.; McArthur, R.D.

    1990-05-01

    The Community Radiation Monitoring Program began its ninth year in the summer of 1989, continuing as an essential portion of the Environmental Protection Agency's long-standing off-site monitoring effort. It is a cooperative venture between the Department of Energy (DOE), the Environmental Protection Agency (EPA), the University of Utah (U of U), and the Desert Research Institute (DRI) of the University of Nevada System. The objectives of the program include enhancing and augmenting the collection of environmental radiation data at selected sites around the Nevada Test Site (NTS), increasing public awareness of that effort, and involving, in as many ways as possible, the residents of the off-site area in these and other areas related to testing nuclear weapons. This understanding and improved communication is fostered by hiring residents of the communities where the monitoring stations are located as program representatives, presenting public education forums in those and other communities, disseminating information on radiation monitoring and related subjects, and developing and maintaining contacts with local citizens and elected officials in the off-site areas. 8 refs., 4 figs., 4 tabs

  15. Can community carers cope?

    Science.gov (United States)

    1989-07-01

    Acquired immunodeficiency syndrome (AIDS) leads to severe social, psychological, and financial consequences for affected families and communities. In response to this stress, service organizations in both developed and developing countries are providing support both to People with AIDS (PWAs) and to their caregivers. In New York, for example, Gay Men's Health Crisis volunteers visit PWAs in hospitals, assist PWAs after discharge with daily chores such as shopping and getting to medical appointments, and provide psychological support through peer and group counseling. The 1st self-help group in Africa, Uganda's AIDS Service Organization (TASO), was established by the widow of an AIDS victim in response to the abandonment of many PWAs by their families. TASO helps families with the practical and financial burdens of caring for AIDS patients, seeks to overcome the fears and misconceptions surrounding the disease, operates a center where those infected with the AIDS virus can gather, and offers income-generating opportunities to PWAs. In the Kagera region of Tanzania, where at least 4000 children have been orphaned by AIDS, villages have allocated community funds for the needs of these children. Other voluntary organizations have focused on providing legal advice to PWAs who have faced discrimination in the workplace or in housing. The World Health Organization's Global Program on AIDS has reiterated its commitment to work with community-based organizations.

  16. Modern community care program

    International Nuclear Information System (INIS)

    Nordin, Staffan

    2000-01-01

    Going into the next millennium do we see nuclear energy? Yes we will see an expanding nuclear sector in the modem community. he modem community that cares for people, health and environment needs nuclear. Energy saves lives. Electricity is efficient use of energy. Energy will be the key to a sustainable society, energy is life. Nuclear energy protects the environment. Nuclear is an integral part of the modern community caring for people, health and environment. The dynamics of the public opinion-forming process and its effects on the nuclear industry are a challenge of the global nuclear industry. Current communications strategy and its consequences are on of the key issues. The nuclear industry must be perceived in certain ways in order to move towards achieving the vision and avoiding the harassment scenario. Each perception goal does not bear the same function within the communications process. As the nuclear industry is oe of the keys to a sustainable society, it must achieve legitimacy in its capacity as an interesting agenda-setter for tackling problems and as an expert. We have to build our communication activities on an open and honest attitude and we have to establish trust and confidence. The nuclear industry must also prove its ability and performance. If this could be achieved there will be an option for the future

  17. Report to the community

    International Nuclear Information System (INIS)

    Braungart, S.; Ripley, M.

    2001-10-01

    In this document, Petro-Canada reports to the stakeholders on non-financial issues that have an impact on the communities in which the company operates. It is the first such annual report. The document touches environmental performance measures, the company's commitment and involvement in the various communities where it has a presence, health and safety, high-performance work environment for the employees, as well as business principles that guide the making of decisions. Some basic information concerning Petro-Canada is presented, followed by an overview of the corporate responsibility. The next section of the report is concerned with the environment. It is further divided into categories such as energy, air quality, water quality, regulatory compliance, environmental investments, waste management, and product quality. The section devoted to employee well-being addresses the work environment, and health and safety. The values and ethical decision-making are discussed in the next section, including the code of business conduct, corporate values, criteria for ethical decision-making, relationship with suppliers and business associates, community investment. The major growth areas, like Newfoundland, Northern Alberta, the Mackenzie Delta all benefit from a special sub-section that brushes on the major accomplishments. The report concludes by a statement concerning the contribution made by Petro-Canada to the Canadian economy. figs

  18. [Community Service Program, Westmont College.

    Science.gov (United States)

    Kistler, Christina

    This report describes a 2-year project at Westmont College, California, which established a Community Service Program with the purposes of decreasing student debt and increasing student participation in community organizations. Eligible students worked 8-10 hours per week for a qualified community agency and received credit towards tuition for the…

  19. Cooking up an Online Community

    Science.gov (United States)

    Valone, Lauren

    2011-01-01

    As museum professionals conceptualize community building, they must now consider the virtual realm. Websites in and of themselves will not generate a community, as it takes sustained communication and interaction by staff to encourage growth. Online communities are complex forces that bring about systematic dualities that in turn stimulate…

  20. The Power of Community Schools

    Science.gov (United States)

    Capers, Natasha; Shah, Shital C.

    2015-01-01

    In this article, Shital Shah, who supports community schools as assistant director for educational issues at the American Federation of Teachers, and Natasha Capers, a coordinator for the New York City Coalition for Educational Justice (CEJ), a parent-led collaborative of unions and community organizations, discuss the community schools movement…

  1. Building a Just Adolescent Community

    Science.gov (United States)

    Enright, Mary Schaefer; Schaefer, Lawrence V.; Schaefer, Patricia S.; Schaefer, Kristin A.

    2008-01-01

    Lawrence Kohlberg, a psychologist, coined the term "Just Community" to describe a community built on trust and resolution, in which each member participates democratically in the development of the rules and regulations that govern their community life (Kohlberg, 1985). In a school, this means that students and teachers alike actively participate…

  2. Community gardening and social cohesion

    NARCIS (Netherlands)

    Veen, E.J.; Bock, B.B.; Berg, Van den W.; Visser, A.J.; Wiskerke, J.S.C.

    2016-01-01

    Community gardens vary in several ways: they are cultivated by different kinds of communities in various locations, entail individual or communal plots and the extent of active participation (e.g. gardening) differs. In this paper, we study seven community gardens with varying organisational

  3. Enhancing Community Service Learning Via Practical Learning Communities

    Directory of Open Access Journals (Sweden)

    Ilana Ronen

    2015-02-01

    Full Text Available The advantages of learning communities focused on analyzing social issues and educational repercussions in the field are presented in this study. The research examines the contribution of a learning community to enhancing student teachers' responsibility and their social involvement. The assumption was that participating in learning community would further implement student teachers' community social involvement while enhancing responsibility in their field of action. A questionnaire aimed to present the student teachers' attitudes involving all aspects of studying in the learning community and their social activity in the community was conducted. The findings pinpointed that there were positive contributions of the learning communities from a personal aspect such as developing self-learning, and learning about “me”, as well as broaden their teaching skills, through methodology for teacher training, and developing reflective thought. These insights can also be implemented in various educational frameworks and during service learning as part of teacher training.

  4. Community interaction and child maltreatment.

    Science.gov (United States)

    Kim, Bomi; Maguire-Jack, Kathryn

    2015-03-01

    The way in which parents interact with their environment may have implications for their likelihood of abuse and neglect. This study examines the parent-environment relationship through community involvement and perception, using social disorganization theory. We hypothesize mothers who participate in their communities and have positive perceptions of them may be less likely to maltreat their children because of the potential protective capacity of neighborhood supports. Using information from the 5 year Fragile Families and Child Wellbeing Study (n=2991), the mother's self-reported acts of psychological and physical maltreatment and neglect are measured. A mother's community involvement index is the number of community activities a mother was involved in, and community perception is measured by two five-item Likert scales assessing perception of community collective efficacy. We analyze the relationship between community variables and each of mother's maltreatment behaviors as well as the interaction between community factors using a series of nested logistic regressions. Higher levels of community involvement are associated with lower levels of psychological aggression. More positive perception of community social control is associated with lower levels of physical assault. A moderation effect of community perception suggests that a mother's perception of her community changes the relationship between community involvement and psychological child abuse. The results provide important policy and empirical implications to build positive and supportive communities as a protective factor in child maltreatment. Getting parents involved in their communities can improve the environment in which children and families develop, and decrease the likelihood that maltreatment will occur. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Integrating Community into the Classroom: Community Gardening, Community Involvement, and Project-Based Learning.

    Science.gov (United States)

    Langhout, Regina Day; Rappaport, Julian; Simmons, Doretha

    2002-01-01

    Culturally relevant, ongoing project-based learning was facilitated in a predominantly African American urban elementary school via a community garden project. The project involved teachers, students, university members, and community members. This article evaluates the project through two classroom-community collaboration models, noting common…

  6. The Entrepreneurial Community College: Bringing Workforce, Economic and Community Development to Virginia Community Colleges.

    Science.gov (United States)

    Drury, Richard L.

    2001-01-01

    Proposes creating an entrepreneurial college within the community college that will offer non-credit courses to the community and workforce. States that the courses would focus on the training needs of community industry, with the employer as the customer, rather than the student. Adds that the proposed college would also focus on community…

  7. Notes on epilithic, epigeic and muscicolous lichens and lichenicolous fungi from rock outcrops in the mountains of northern Greece

    DEFF Research Database (Denmark)

    Christensen, Steen; Alstrup, Vagn

    2013-01-01

    Of the 154 taxa reported, 27 species are new to Greece, 9 new to the Greek mainland and 39 new to one or more provinces. Many of these records represent substantial range extensions of species with Central European or arctic-boreal distribution. Distribution data are briefly discussed and notes a...

  8. Sharing Resources in Educational Communities

    Directory of Open Access Journals (Sweden)

    Anoush Margarayn

    2010-06-01

    Full Text Available The paper explores the implications of mobility within educational communities for sharing and reuse of educational resources. The study begins by exploring individuals’ existing strategies for sharing and reusing educational resources within localised and distributed communities, with particular emphasis on the impact of geographic location on these strategies. The results indicate that the geographic distribution of communities has little impact on individuals’ strategies for resource management, since many individuals are communicating via technology tools with colleagues within a localised setting. The study points to few major differences in the ways in which individuals within the localised and distributed communities store, share and collaborate around educational resources. Moving beyond the view of individuals being statically involved in one or two communities, mobility across communities, roles and geographic location are formulated and illustrated through eight scenarios. The effects of mobility across these scenarios are outlined and a framework for future research into mobility and resource sharing within communities discussed.

  9. Community Psychology and Community Mental Health: A Call for Reengagement.

    Science.gov (United States)

    Townley, Greg; Brown, Molly; Sylvestre, John

    2018-03-01

    Community psychology is rooted in community mental health research and practice and has made important contributions to this field. Yet, in the decades since its inception, community psychology has reduced its focus on promoting mental health, well-being, and liberation of individuals with serious mental illnesses. This special issue endeavors to highlight current efforts in community mental health from our field and related disciplines and point to future directions for reengagement in this area. The issue includes 12 articles authored by diverse stakeholder groups. Following a review of the state of community mental health scholarship in the field's two primary journals since 1973, the remaining articles center on four thematic areas: (a) the community experience of individuals with serious mental illness; (b) the utility of a participatory and cross-cultural lens in our engagement with community mental health; (c) Housing First implementation, evaluation, and dissemination; and (d) emerging or under-examined topics. In reflection, we conclude with a series of challenges for community psychologists involved in future, transformative, movements in community mental health. © Society for Community Research and Action 2018.

  10. Monitoring natural phytoplankton communities

    DEFF Research Database (Denmark)

    Haraguchi, L.; Jakobsen, H. H.; Lundholm, Nina

    2017-01-01

    -consuming and/or expensive, limiting sampling frequency. The use of faster methods, such as flow cytometry, has become more frequent in phytoplankton studies, although comparisons between this technique and traditional ones are still scarce. This study aimed to assess if natural phytoplankton communities...... carbon biomass with PFCM, applying the same conversion factors as for microscopy. Biomasses obtained with PFCM, estimated from live cells, were higher than microscopy for natural samples. We conclude that PFCM results are comparable to classical techniques, yet the data from PFCM had poor taxonomic...

  11. Community energy policy

    International Nuclear Information System (INIS)

    Redondo Melchor, N.; Redondo Quintela, F.

    1994-01-01

    The twelve Member states of the European Union will attempt to make their national energy policies converge. Nevertheless the basis of the so called ''Community Energy Policy'' is not this convergence but rather the achievement of a new internal market, the Energy Market, where sources and forms of energy may circulate freely between countries. This aim derives from a change of orientation, dating back some years, when market integration was attempted instead of continuing with the mere unification of national policies. In this paper we summarize the most relevant aspects of the liberalization process and give some of its internal and external repercussions on the European Union. (Author)

  12. Auditing Community Software Development

    Directory of Open Access Journals (Sweden)

    Mészáros Gergely

    2015-12-01

    Full Text Available In accordance with European efforts related to Critical Information Infrastructure Protection, in Hungary a special department called LRL-IBEK has been formed which is designated under the Disaster Management. While specific security issues of commercial applications are well understood and regulated by widely applied standards, increasing share of information systems are developed partly or entirely in a different way, by the community. In this paper different issues of the open development style will be discussed regarding the high requirements of Critical Information Infrastructures, and possible countermeasures will be suggested for the identified problems.

  13. Perifiton en el mesohábitat de corredera de un arroyo serrano: dinámica estacional en relación a variables físico-químicas Periphyton in a run mesohabitat of a mountain stream: seasonal dynamics related to physicochemical parameters

    Directory of Open Access Journals (Sweden)

    M. Andrea Amaidén

    2011-12-01

    Full Text Available Se analizó la composición y la distribución de algas perifíticas en un mesohábitat de corredera del arroyo Achiras, al suroeste de Río Cuarto, Córdoba, estacionalmente durante el período 2005-2006. Se seleccionaron tres sitios de muestreo en el gradiente longitudinal de una zona serrana y pedemontana, donde se realizará la construcción de una presa. Esta investigación aporta los primeros resultados sobre la comunidad algal perifítica y sienta las bases para una profundización futura. Se determinaron 267 taxones, la clase Bacillariophyceae aportó 174, Chlorophyceae 78 y Cyanophyceae 15. La máxima similitud entre las muestras fue de 100 %, correspondiendo a los sitios 1 y 2 durante la primavera. La mayor abundancia promedio fue de 320.486 org.cm-2 para el sitio 3 durante el verano. La clasificación de las muestras separó dos grupos principales y conformó subgrupos. El CCA efectuado a muestras y especies mostró una separación del sitio 3, ubicado en el pedemonte, con mayor porcentaje de sedimento de menor tamaño y una menor velocidad de corriente respecto a los otros. Los sitios 1 y 2 se caracterizaron, en general, por un gradiente de pH. Todos los grupos formados por la clasificación estuvieron integrados, en su mayoría, por organismos del orden Biraphidales.Composition and distribution of periphytic algae in a run mesohabitat of the stream Achiras, southwest of Rio Cuarto, Cordoba, were analyzed seasonally during 2005-2006. Three sites were selected for sampling in the longitudinal gradient of a mountainous and piedmont area, where the construction of a dam is considered. This research provides the first results on the algal periphytic community and lays the groundwork for a deepening future. A total of 267 taxa were identified, the class Bacillariophyceae contributed with 174 taxa, Chlorophyceae with 78 and Cyanophyceae with 15. The maximum similarity between samples was 100%, corresponding to sites 1 and 2 during the

  14. International Journal of Web Based Communities

    DEFF Research Database (Denmark)

    2006-01-01

    Special Issue on Knowledge Communication, culture and communities of practice in web based communities. ......Special Issue on Knowledge Communication, culture and communities of practice in web based communities. ...

  15. Community Cloud Computing

    Science.gov (United States)

    Marinos, Alexandros; Briscoe, Gerard

    Cloud Computing is rising fast, with its data centres growing at an unprecedented rate. However, this has come with concerns over privacy, efficiency at the expense of resilience, and environmental sustainability, because of the dependence on Cloud vendors such as Google, Amazon and Microsoft. Our response is an alternative model for the Cloud conceptualisation, providing a paradigm for Clouds in the community, utilising networked personal computers for liberation from the centralised vendor model. Community Cloud Computing (C3) offers an alternative architecture, created by combing the Cloud with paradigms from Grid Computing, principles from Digital Ecosystems, and sustainability from Green Computing, while remaining true to the original vision of the Internet. It is more technically challenging than Cloud Computing, having to deal with distributed computing issues, including heterogeneous nodes, varying quality of service, and additional security constraints. However, these are not insurmountable challenges, and with the need to retain control over our digital lives and the potential environmental consequences, it is a challenge we must pursue.

  16. Towards sustainable urban communities

    International Nuclear Information System (INIS)

    Haapio, Appu

    2012-01-01

    Requirements for the assessment tools of buildings have increased, assessing of building components or separate buildings is not enough. Neighbourhoods, built environment, public transportations, and services, should be considered simultaneously. Number of population living in urban areas is high and increasing rapidly. Urbanisation is a major concern due to its detrimental effects on the environment. The aim of this study is to clarify the field of assessment tools for urban communities by analysing the current situation. The focus is on internationally well known assessment tools; BREEAM Communities, CASBEE for Urban Development and LEED for Neigborhood Development. The interest towards certification systems is increasing amongst the authorities, and especially amongst the global investors and property developers. Achieved certifications are expected to bring measureable publicity for the developers. The assessment of urban areas enables the comparison of municipalities and urban areas, and notably supports decision making processes. Authorities, city planners, and designers would benefit most from the use of the tools during the decision making process. - Highlights: ► The urban assessment tools have strong linkage to the region. ► The tools promote complementary building and retrofitting existing sites. ► Sharing knowledge and experiences is important in the development of the tools.

  17. Community assembly and coexistence in communities of arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Vályi, Kriszta; Mardhiah, Ulfah; Rillig, Matthias C; Hempel, Stefan

    2016-10-01

    Arbuscular mycorrhizal fungi are asexual, obligately symbiotic fungi with unique morphology and genomic structure, which occupy a dual niche, that is, the soil and the host root. Consequently, the direct adoption of models for community assembly developed for other organism groups is not evident. In this paper we adapted modern coexistence and assembly theory to arbuscular mycorrhizal fungi. We review research on the elements of community assembly and coexistence of arbuscular mycorrhizal fungi, highlighting recent studies using molecular methods. By addressing several points from the individual to the community level where the application of modern community ecology terms runs into problems when arbuscular mycorrhizal fungi are concerned, we aim to account for these special circumstances from a mycocentric point of view. We suggest that hierarchical spatial structure of arbuscular mycorrhizal fungal communities should be explicitly taken into account in future studies. The conceptual framework we develop here for arbuscular mycorrhizal fungi is also adaptable for other host-associated microbial communities.

  18. Community Health Warriors: Marshallese Community Health Workers' Perceptions and Experiences with CBPR and Community Engagement.

    Science.gov (United States)

    Purvis, Rachel S; Bing, Williamina Ioanna; Jacob, Christopher J; Lang, Sharlynn; Mamis, Sammie; Ritok, Mandy; Rubon-Chutaro, Jellesen; McElfish, Pearl Anna

    2017-01-01

    Our manuscript highlights the viewpoints and reflections of the native Marshallese community health workers (CHWs) engaged in research with the local Marshallese community in Northwest Arkansas. In particular, this paper documents the vital role Marshallese CHWs play in the success of programs and research efforts. The negative health effects of nuclear testing in the Marshall Islands has been passed down through many generations, along with unfavorable attitudes toward the U.S. government and researchers. However, the community-based participatory research (CBPR) approach used by the University of Arkansas for Medical Sciences (UAMS) has allowed the native Marshallese CHWs to become advocates for the Marshallese community. The use of native CHWs has also leveled the power dynamics that can be a barrier to community-based research, and has strengthened trust with community stakeholders. Our paper shows how using Marshallese CHWs can produce positive health outcomes for the Marshallese community.

  19. Towards Community - Reflections on Community Psychiatry, Culture and Alterity

    Directory of Open Access Journals (Sweden)

    Ana Neto

    2015-06-01

    Full Text Available Introduction: The constant transformation of  communities  and  its relationship  with mental illness has been studied and debated for the past decades, although it is still not clear how it has been incorporated in clinical practice.Aims: The authors propose to review the relevance to Psychiatry, especially Community Psychiatry, of understanding  communities as well as the methodologies and conceptual frameworks that allow that approach.Methods: Selected and critical review of the literature about Community Psychiatry and Culture, Communities, and Social Inequity and Mental Health.Results: The authors start by reviewing the meaning  of  Community and the  defining principles of Community Psychiatry in their relationships with  cultural  sensitivity.  This aspect is illustrated with two examples of the impact of culture and alterity in the understanding of Mental Health and Service Organization, one at the level of International and Global Mental Health, and the other at the local communities’ level. In this context, participatory action research is highlighted.Conclusions: Psychiatry,  in  particular Community  Psychiatry,  by acknowledging a  wide  range  of  methodologies  and  being open  to transdisciplinary  models, is in a privileged position of electing communities as a field of investigation and integrate it in its praxis.

  20. Communities matter: Institutional preconditions for community renewable energy

    International Nuclear Information System (INIS)

    Wirth, Steffen

    2014-01-01

    Energy transitions are high on political agendas. From a practical viewpoint, community approaches are deemed essential in order to transition from a predominantly centralized energy supply to a decentralized one, and to exploit the potential of renewable energies. In this paper, I discuss how the emergence of community-based energy projects can be analyzed from an institutional perspective. In this context, a ‘community’ is treated as an individual institutional order that shapes decisions. I examine how community structures the implementation of biogas cooperatives in the Autonomous Province of South Tyrol in Northern Italy. My findings suggest that ‘community spirit’, a cooperative tradition, and the norms of locality and responsibility are central drivers behind the emergence and constitution of biogas cooperatives. Not only do these institutional features of community influence the decision concerning which farmers are in or out but also plant location and scale. I argue that ‘community’ is a necessary analytical category for understanding community energy. - Highlights: • I analyze the emergence and constitution of biogas cooperatives in South Tyrol. • Emerging processes and the principal constitutions are similar. • Institutional forces influenced the biogas cooperatives' emergence and constitution. • Biogas cooperatives are decisively shaped by community spirit and local tradition. • The concept of community is used as an explanatory category for community energy

  1. Effects of fish density and river fertilization on algal standing stocks, invertebrates communities, and fish production in an Arctic River

    Science.gov (United States)

    Deegan, Linda A.; Peterson, B.J.; Golden, H.; McIvor, C.C.; Miller, M.C.

    1997-01-01

    This study examined the relative importance of bottom-up and top-down controls of an arctic stream food web by simultaneous manipulation of the top predator and nutrient availability. We created a two-step trophic system (algae to insects) by removal of the top predator (Arctic grayling, Thymallus arcticus) in fertilized and control stream reaches. Fish abundance was also increased 10 times to examine the effect of high fish density on stream ecosystem dynamics and fish. We measured the response of epilithic algae, benthic and drifting insects, and fish to nutrient enrichment and to changes in fish density. Insect grazers had little effect on algae and fish had little effect on insects. In both the control and fertilized reaches, fish growth, energy storage, and reproductive response of females declined with increased fish density. Fish growth and energy storage were more closely correlated with per capita insect availability than with per capita algal standing stock

  2. L-Lake macroinvertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

  3. Community Members Draw the Line

    Directory of Open Access Journals (Sweden)

    Gregory Freeland

    2014-06-01

    Full Text Available This study investigates whether a community-based task force’s redistricting plan in Ventura County, California, positively affected fair representation, social equity issues, community interests, and the electoral process. Examination and evaluation of the organizational strategies and collaborations involved in the task force’s redistricting process find that the Board of Supervisors districts that members of the community drew were successful in improving and maintaining fair representation. This finding is based on comparing supervisorial votes and policies with community members’ votes on state propositions and local measures, in addition to conducting interviews with task force members, politicians, and community activists. This study finds that citizen participation in governmental processes improves overall community health and political participation.

  4. L-Lake macroinvertebrate community

    International Nuclear Information System (INIS)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake's macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors

  5. What is microbial community ecology?

    Science.gov (United States)

    Konopka, Allan

    2009-11-01

    The activities of complex communities of microbes affect biogeochemical transformations in natural, managed and engineered ecosystems. Meaningfully defining what constitutes a community of interacting microbial populations is not trivial, but is important for rigorous progress in the field. Important elements of research in microbial community ecology include the analysis of functional pathways for nutrient resource and energy flows, mechanistic understanding of interactions between microbial populations and their environment, and the emergent properties of the complex community. Some emergent properties mirror those analyzed by community ecologists who study plants and animals: biological diversity, functional redundancy and system stability. However, because microbes possess mechanisms for the horizontal transfer of genetic information, the metagenome may also be considered as a community property.

  6. Civic communities and urban violence.

    Science.gov (United States)

    Doucet, Jessica M; Lee, Matthew R

    2015-07-01

    Civic communities have a spirit of entrepreneurialism, a locally invested population and an institutional structure fostering civic engagement. Prior research, mainly confined to studying rural communities and fairly large geographic areas, has demonstrated that civic communities have lower rates of violence. The current study analyzes the associations between the components of civic communities and homicide rates for New Orleans neighborhoods (census tracts) in the years following Hurricane Katrina. Results from negative binomial regression models adjusting for spatial autocorrelation reveal that community homicide rates are lower where an entrepreneurial business climate is more pronounced and where there is more local investment. Additionally, an interaction between the availability of civic institutions and resource disadvantage reveals that the protective effects of civic institutions are only evident in disadvantaged communities. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.

  8. Community colleges and economic mobility

    OpenAIRE

    Natalia A. Kolesnikova

    2010-01-01

    This paper examines the role of community colleges in the U.S. higher education system and their advantages and shortcomings. In particular, it discusses the population of community college students and economic returns to community college education for various demographic groups. It offers new evidence on the returns to an associate's degree. Furthermore, the paper uses data from the National Survey of College Graduates to compare educational objectives, progress, and labor market outcomes ...

  9. Community Detection for Large Graphs

    KAUST Repository

    Peng, Chengbin

    2014-05-04

    Many real world networks have inherent community structures, including social networks, transportation networks, biological networks, etc. For large scale networks with millions or billions of nodes in real-world applications, accelerating current community detection algorithms is in demand, and we present two approaches to tackle this issue -A K-core based framework that can accelerate existing community detection algorithms significantly; -A parallel inference algorithm via stochastic block models that can distribute the workload.

  10. Growth Hacking a Global Community

    OpenAIRE

    Sarkkinen, Laura; Rauhala, Marita

    2015-01-01

    As technology is developing at a fast phase people are engaging in community activities more and more online, either by extending their offline social life or by creating themselves a whole new parallel life as a member of virtual community. Companies behind communities are rivaling for attention and need to come up with increasingly clever tactics to attract and engage new members. In this thesis the relatively new phenomenon of growth hacking, the use of unconventional methods in order ...

  11. A nuclear community's perspective

    International Nuclear Information System (INIS)

    1987-09-01

    This submission delineates a perspective derived from the experience of a community which has lived with the nuclear industry since its beginnings in Canada, 45 years ago. Much has been accomplished in both basic and applied research in that time, and the industry continues to be recognized worldwide as a leader in solving high-technology problems. However, recent funding cuts have seriously jeopardized the industry's ability to maintain this high standard. Current anti-nuclear attitudes among our elected and appointed officials respond more to today's political fashions than tomorrow's evident needs. The town of Deep River believes that the industry has demonstrated a superb safety record in the past. If common sense prevails in matters of safety, and if appropriate levels of funding are maintained, the nuclear industry will continue to be a source of pride for all concerned

  12. Urban Climate Risk Communities

    DEFF Research Database (Denmark)

    Blok, Anders

    2016-01-01

    of Beck’s forward-looking agenda for a post-Euro-centric social science, outlines the contours of such an urban-cosmopolitan ‘realpolitik’ of climate risks, as this is presently unfolding across East Asian world cities. Much more than a theory-building endeavour, the essay suggests, Beck’s sociology......Ulrich Beck’s cosmopolitan sociology affords a much-needed rethinking of the transnational politics of climate change, not least in pointing to an emerging inter-urban geography of world cities as a potential new source of community, change and solidarity. This short essay, written in honour...... provides a standing invitation for further transnational dialogue and collaborative empirical work, in East Asia and beyond, on what are, arguably, the defining challenges for the 21st century world of global risks....

  13. Communities under climate change

    DEFF Research Database (Denmark)

    Nogues, David Bravo; Rahbek, Carsten

    2011-01-01

    The distribution of species on Earth and the interactions among them are tightly linked to historical and contemporary climate, so that global climate change will transform the world in which we live. Biological models can now credibly link recent decadal trends in field data to climate change......, but predicting future impacts on biological communities is a major challenge. Attempts to move beyond general macroecological predictions of climate change impact on one hand, and observations from specific, local-scale cases, small-scale experiments, or studies of a few species on the other, raise a plethora...... of unanswered questions. On page 1124 of this issue, Harley (1) reports results that cast new light on how biodiversity, across different trophic levels, responds to climate change....

  14. Communities and Values

    DEFF Research Database (Denmark)

    Salice, Alessandro

    2016-01-01

    is clearly illustrated by a by now rather standard approach to we-ness, which seeks to locate this property either in the subject of a given attitude (which, most perspicuously, is used to being characterized as an intention), or in the mode of the attitude or in its content. This view also suggests...... that there is one prototypical notion of group which conceptually has to be traced back to one of the three constituents of an intentional attitude and that the main way to access the notion of a group is by means of the concept of intention and/or intentional action. The present paper tackles a fairly divergent...... approach to the ontology of groups put forward by Dietrich von Hildebrand in his book on the Metaphysics of Community. First, von Hildebrand argues that there are different kinds of social groups and that, accordingly, individuals can be ‘together’ in radically different ways. In particular, he...

  15. FOILFEST :community enabled security.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Judy Hennessey; Johnson, Curtis Martin; Whitley, John B.; Drayer, Darryl Donald; Cummings, John C., Jr. (.,; .)

    2005-09-01

    The Advanced Concepts Group of Sandia National Laboratories hosted a workshop, ''FOILFest: Community Enabled Security'', on July 18-21, 2005, in Albuquerque, NM. This was a far-reaching look into the future of physical protection consisting of a series of structured brainstorming sessions focused on preventing and foiling attacks on public places and soft targets such as airports, shopping malls, hotels, and public events. These facilities are difficult to protect using traditional security devices since they could easily be pushed out of business through the addition of arduous and expensive security measures. The idea behind this Fest was to explore how the public, which is vital to the function of these institutions, can be leveraged as part of a physical protection system. The workshop considered procedures, space design, and approaches for building community through technology. The workshop explored ways to make the ''good guys'' in public places feel safe and be vigilant while making potential perpetrators of harm feel exposed and convinced that they will not succeed. Participants in the Fest included operators of public places, social scientists, technology experts, representatives of government agencies including DHS and the intelligence community, writers and media experts. Many innovative ideas were explored during the fest with most of the time spent on airports, including consideration of the local airport, the Albuquerque Sunport. Some provocative ideas included: (1) sniffers installed in passage areas like revolving door, escalators, (2) a ''jumbotron'' showing current camera shots in the public space, (3) transparent portal screeners allowing viewing of the screening, (4) a layered open/funnel/open/funnel design where open spaces are used to encourage a sense of ''communitas'' and take advantage of citizen ''sensing'' and funnels are technological

  16. The community comes to campus: the Patient and Community Fair.

    Science.gov (United States)

    Towle, Angela; Godolphin, William; Kline, Cathy

    2015-08-01

    Community-based learning connects students with local communities so that they learn about the broad context in which health and social care is provided; however, students usually interact with only one or a few organisations that serve a particular population. One example of a community-based learning activity is the health fair in which students provide health promotion and screening for local communities. We adapted the health fair concept to develop a multi-professional educational event at which, instead of providing service, students learn from and about the expertise and resources of not-for-profit organisations. The fair is an annual 1-day event that students can attend between, or in place of, classes. Each community organisation has a booth to display information. One-hour 'patient panels' are held on a variety of topics throughout the day. Evaluation methods include questionnaires, exit interviews and visitor tracking sheets. Over 5 years (2009-2013), the fair increased in size with respect to estimated attendance, number of participating organisations, number of patient panels and number of students for whom the fair is a required curriculum component. Students learn about a range of patient experiences and community resources, and information about specific diseases or conditions. The fair is an efficient way for students to learn about a range of community organisations. It fosters university-community engagement through continuing connections between students, faculty members and community organisations. Lessons learned include the need for community organisations to have techniques to engage students, and ways to overcome challenges of evaluating an informal 'drop-in' event. The fair is an efficient way for students to learn about a range of community organisations. © 2015 John Wiley & Sons Ltd.

  17. Community photosynthesis of aquatic macrophytes

    DEFF Research Database (Denmark)

    Binzer, T.; Sand-Jensen, K.; Middelboe, A. L.

    2006-01-01

    We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition of photosynt......We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition...

  18. Parasite communities: patterns and processes

    National Research Council Canada - National Science Library

    Esch, Gerald W; Bush, Albert O; Aho, John M

    1990-01-01

    .... Taking examples from many hosts including molluscs, marine and freshwater fish, amphibians, reptiles, birds and mammals, this book shows how parasitic communities are influenced by a multitude...

  19. Community Engagement in a Graduate-Level Community Literacy Course

    Science.gov (United States)

    Marshall Bowen, Lauren; Arko, Kirsti; Beatty, Joel; Delaney, Cindy; Dorpenyo, Isidore; Moeller, Laura; Roberts, Elsa; Velat, John

    2014-01-01

    A case study of a graduate-level community literacy seminar that involved a tutoring project with adult digital literacy learners, this essay illustrates the value of community outreach and service-learning for graduate students in writing studies. Presenting multiple perspectives through critical reflection, student authors describe how their…

  20. Community Capitals as Community Resilience to Climate Change: Conceptual Connections

    Directory of Open Access Journals (Sweden)

    Shaikh Mohammad Kais

    2016-12-01

    Full Text Available In the last few decades, disaster risk reduction programs and climate initiatives across the globe have focused largely on the intimate connections between vulnerability, recovery, adaptation, and coping mechanisms. Recent focus, however, is increasingly paid to community resilience. Community, placed at the intersection between the household and national levels of social organization, is crucial in addressing economic, social, or environmental disturbances disrupting human security. Resilience measures a community’s capability of bouncing back—restoring the original pre-disaster state, as well as bouncing forward—the capacity to cope with emerging post-disaster situations and changes. Both the ‘bouncing back’ and ‘moving forward’ properties of a community are shaped and reshaped by internal and external shocks such as climate threats, the community’s resilience dimensions, and the intensity of economic, social, and other community capitals. This article reviews (1 the concept of resilience in relation to climate change and vulnerability; and (2 emerging perspectives on community-level impacts of climate change, resilience dimensions, and community capitals. It argues that overall resilience of a place-based community is located at the intersection of the community’s resilience dimensions, community capitals, and the level of climate disruptions.

  1. Community Capitals as Community Resilience to Climate Change: Conceptual Connections

    Science.gov (United States)

    Kais, Shaikh Mohammad; Islam, Md Saidul

    2016-01-01

    In the last few decades, disaster risk reduction programs and climate initiatives across the globe have focused largely on the intimate connections between vulnerability, recovery, adaptation, and coping mechanisms. Recent focus, however, is increasingly paid to community resilience. Community, placed at the intersection between the household and national levels of social organization, is crucial in addressing economic, social, or environmental disturbances disrupting human security. Resilience measures a community’s capability of bouncing back—restoring the original pre-disaster state, as well as bouncing forward—the capacity to cope with emerging post-disaster situations and changes. Both the ‘bouncing back’ and ‘moving forward’ properties of a community are shaped and reshaped by internal and external shocks such as climate threats, the community’s resilience dimensions, and the intensity of economic, social, and other community capitals. This article reviews (1) the concept of resilience in relation to climate change and vulnerability; and (2) emerging perspectives on community-level impacts of climate change, resilience dimensions, and community capitals. It argues that overall resilience of a place-based community is located at the intersection of the community’s resilience dimensions, community capitals, and the level of climate disruptions. PMID:27929448

  2. Designing to support community gardens by going beyond community gardens

    NARCIS (Netherlands)

    Wang, X.; Wakkary, R.; Rau, P.-L.P.

    2017-01-01

    Community gardens connect to many organizations in order to receive and offer resources and services. The complex sociotechnical systems in which community gardens inhabit bring both opportunities and challenges for designers who endeavor to support them. In this study, we investigated three

  3. Indigenous knowledge systems, local community and community in ...

    African Journals Online (AJOL)

    The title of the paper requires some brief reflection on the main topics implied. It is appropriate to start off with a definition of Indigenous Knowledge Systems (IKS) as well as a statement regarding the constitutional status of a community. Thereafter I will expand on the merits of IKS towards community development as well as ...

  4. The community ecology of pathogens: coinfection, coexistence and community composition.

    Science.gov (United States)

    Seabloom, Eric W; Borer, Elizabeth T; Gross, Kevin; Kendig, Amy E; Lacroix, Christelle; Mitchell, Charles E; Mordecai, Erin A; Power, Alison G

    2015-04-01

    Disease and community ecology share conceptual and theoretical lineages, and there has been a resurgence of interest in strengthening links between these fields. Building on recent syntheses focused on the effects of host community composition on single pathogen systems, we examine pathogen (microparasite) communities using a stochastic metacommunity model as a starting point to bridge community and disease ecology perspectives. Such models incorporate the effects of core community processes, such as ecological drift, selection and dispersal, but have not been extended to incorporate host-pathogen interactions, such as immunosuppression or synergistic mortality, that are central to disease ecology. We use a two-pathogen susceptible-infected (SI) model to fill these gaps in the metacommunity approach; however, SI models can be intractable for examining species-diverse, spatially structured systems. By placing disease into a framework developed for community ecology, our synthesis highlights areas ripe for progress, including a theoretical framework that incorporates host dynamics, spatial structuring and evolutionary processes, as well as the data needed to test the predictions of such a model. Our synthesis points the way for this framework and demonstrates that a deeper understanding of pathogen community dynamics will emerge from approaches working at the interface of disease and community ecology. © 2015 John Wiley & Sons Ltd/CNRS.

  5. Community Connections. Time Warner Community Responsibility Report, 1998-2000.

    Science.gov (United States)

    Owens, Jane; Stein, Carol

    This report highlights efforts by Time Warner personnel to strengthen community connections through various programs and services aimed at supporting: education, the arts, volunteerism, diversity, and business-community action. The report is divided into sections focusing on each of these areas. The first section, Education, describes programs…

  6. Science and Community Engagement: Connecting Science Students with the Community

    Science.gov (United States)

    Lancor, Rachael; Schiebel, Amy

    2018-01-01

    In this article we describe a course on science outreach that was developed as part of our college's goal that all students participate in a meaningful community engagement experience. The Science & Community Engagement course provides a way for students with science or science-related majors to learn how to effectively communicate scientific…

  7. Community Currency in Korea : How do we envision Community Currency?

    NARCIS (Netherlands)

    J. Kang (Joonmo); B.E. Hong (Baeg)

    2015-01-01

    textabstractCommunity currency schemes were first introduced in Korea in 1998. Since then, there have been many efforts to use them but no report or academic research on the topic in Korea. Thus, we conducted a field investigation to identify the scope of community currency schemes in Korea and as

  8. From Campuses to Communities: Community-Based Cultism and ...

    African Journals Online (AJOL)

    Due to the criminal activities of the cult groups in the NDR and ineptitude of the police, communities have responded by creating vigilante groups but this has only promoted cycle of violence. The paper recommended that government should tackle community-based cultism and also strengthen the Nigeria Police Force to be ...

  9. Role of Community Radio for Community Development in Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Anowarul Arif Khan

    2017-04-01

    Full Text Available Community radio is a medium of expressing and sharing views, thoughts, ideas, problems and prospects of rural, disadvantaged, vulnerable and hard to reach population with the mainstream population. As the media of root level people of the disadvantaged areas, Community radio has become popular in recent years and it has opened a new arena for both the policy makers as well as grassroots people to be involved in the development process of their community. There are about 17 Community Radios broadcasting 135 hours programmes in a day across the country. The Community Radio can help us in addressing social, economic, cultural, educational, health, water and sanitation and disaster related issues more effectively and strategically. In order to highlight the importance and effectiveness of community radio for the community development of Bangladesh, this study has been conducted based on the secondary data. This is a group effort that has become successful by the co-operation of many individuals and institutions. Access to Information (a2i Programme would like to express sincere gratitude to Monisha Mohonto, Project Focal and Bakul Mohonto, Program Assistant, BTV for introducing such an innovative project. As this is a new concept, there is no significant study has been conducted. Therefore the study has been directed to explore the importance of community FM radio in Bangladesh particularly in remote and rural areas.

  10. Renewal Strategy and Community Based Organisations in Community

    African Journals Online (AJOL)

    FBL

    organisations in the study areas and Community-Based Poverty Reduction. Programme ... regions or areas. In Nigeria, for ... industries in the growing and developing urban areas. ..... Security network is also provided by the community. To ..... Development Efforts in Nigeria: Case Study of Anambra and Oyo State, NISER.

  11. Using communities that care for community child maltreatment prevention.

    Science.gov (United States)

    Salazar, Amy M; Haggerty, Kevin P; de Haan, Benjamin; Catalano, Richard F; Vann, Terri; Vinson, Jean; Lansing, Michaele

    2016-03-01

    The prevention of mental, emotional, and behavioral (MEB) disorders among children and adolescents is a national priority. One mode of implementing community-wide MEB prevention efforts is through evidence-based community mobilization approaches such as Communities That Care (CTC). This article provides an overview of the CTC framework and discusses the adaptation process of CTC to prevent development of MEBs through preventing child abuse and neglect and bolstering child well-being in children aged 0 to 10. Adaptations include those to the intervention itself as well as those to the evaluation approach. Preliminary findings from the Keeping Families Together pilot study of this evolving approach suggest that the implementation was manageable for sites, and community board functioning and community adoption of a science-based approach to prevention in pilot sites looks promising. Implications and next steps are outlined. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  12. Is a community still a community? Reviewing definitions of key terms in community ecology

    OpenAIRE

    Stroud, James T.; Bush, Michael R.; Ladd, Mark C.; Nowicki, Robert J.; Shantz, Andrew A.; Sweatman, Jennifer

    2015-01-01

    Abstract Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth et?al. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; ?community,? ?assemblage,? ?guild,? and ?ensemble?. We revisit Fauth et?al.'s conclusion and discuss how the use of these terms has changed over time since their review. An update...

  13. Assessing Community Leadership: Understanding Community Capacity for Health Improvement.

    Science.gov (United States)

    Castle, Billie; Wendel, Monica; Kelly Pryor, Brandy N; Ingram, Monique

    The purpose of this study was to pilot a quantitative instrument to measure aspects of community leadership within an assessment framework. The instrument includes 14 Likert-type questions asking residents how they perceive leaders within 5 sectors: Louisville Metro Council/Mayor's Office, the faith community, education, business, and the civic sector. Louisville/Jefferson County, Kentucky, has a population of about 743 000 residents. Respondents were asked to examine leadership within West Louisville, an economically deprived area of the city made up of 9 contiguous neighborhoods. This area is predominantly African American (78% compared with 22% in Louisville Metro), with an overall poverty rate of 43% (compared with 18% in Louisville Metro), and unemployment rate of 23% (compared with 8% in Louisville Metro). Residents of West Louisville are looking to leadership to address many of the inequities. Twenty-seven participants representing 7 community sectors completed the survey, of whom 90% work in West Louisville. The instrument measured local perceptions of leadership strength, effectiveness, trust, communication, community building, and leadership development. The majority of respondents agree that strong leadership exists across the 5 sectors, with variation regarding perceptions of the quality of that leadership. City leadership within the Mayor's Office and Metro Council is largely viewed positively, while the growing tensions within the education sector were reflected in the survey results. The perception of community leadership is important to understanding local community capacity to improve health and also inclusivity of community voice in the assessment and community improvement processes. Results from such assessments can offer useful information for strengthening community capacity and sustaining relationships needed to enact progressive and equitable solutions to address local issues. Leaders in a variety of settings can utilize this instrument to

  14. Trust Discovery in Online Communities

    Science.gov (United States)

    Piorkowski, John

    2014-01-01

    This research aims to discover interpersonal trust in online communities. Two novel trust models are built to explain interpersonal trust in online communities drawing theories and models from multiple relevant areas, including organizational trust models, trust in virtual settings, speech act theory, identity theory, and common bond theory. In…

  15. Community-acquired bacterial meningitis

    NARCIS (Netherlands)

    van de Beek, Diederik; Brouwer, Matthijs; Hasbun, Rodrigo; Koedel, Uwe; Whitney, Cynthia G.; Wijdicks, Eelco

    2016-01-01

    Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma

  16. Marketing Model for Community College.

    Science.gov (United States)

    Chahin, Jaime

    In order to survive projected enrollment decreases and to better serve nontraditional students, community colleges must develop marketing plans that make effective use of five community resources: local school system personnel, business and industry, civic and social service agencies, college personnel, and the local media. In approaching these…

  17. Distance Learning for Community Education

    Science.gov (United States)

    Cook, Anthony A.

    2010-01-01

    This article takes a look at the influence of technology on curriculum and teaching. It specifically examines the new wave of available technology and the opportunity for schools to make inroads into community outreach by engaging new, technological learning methods. The relationship among community education, public school relations, and distance…

  18. Strengthening community resilience: a toolkit

    NARCIS (Netherlands)

    Davis, Scott; Duijnhoven, Hanneke; Dinesen, Cecilie; Kerstholt, Johanna Helena

    2016-01-01

    While community resilience is said to have gained a lot of traction politically and given credence by disaster management professionals, this perception is not always shared by the individual members of communities. One solution to addressing the difficulty of individuals ‘conceptualising’ the

  19. Opening up closed policy communities.

    NARCIS (Netherlands)

    Termeer, C.J.A.M.; Werkman, R.A.

    2010-01-01

    Agricultural policy networks have served as classic cases of closed policy communities, facing pressure to open up. However attempts to involve new stakeholders slowly move forward. This paper addresses the question why it is so difficult to open up agricultural communities and what might help to

  20. A Community Patient Demographic System

    OpenAIRE

    Gabler, James M.; Simborg, Donald W.

    1985-01-01

    A Community Patient Demographic System is described. Its purpose is to link patient identification, demographic and insurance information among multiple organizations in a community or among multiple registration systems within the same organization. This function requires that there be a competent patient identification methodology and clear definition of local responsibilities for number assignment and database editing.

  1. Community College Employee Wellness Programs

    Science.gov (United States)

    Thornton, L. Jay; Johnson, Sharon

    2010-01-01

    This paper describes the prevalence and characteristics of employee wellness programs in public community colleges accredited by the Southern Association of Colleges and Schools (SACS). A random sample of 250 public community colleges accredited by SACS was mailed a 46-item employee-wellness program survey. The survey solicited program information…

  2. Otitis Media, Learning and Community.

    Science.gov (United States)

    McSwan, David; Clinch, Emma; Store, Ron

    2001-01-01

    A 3-year research project in Queensland (Australia) implemented educational and health strategies to ameliorate effects of otitis media at three schools in remote Aboriginal communities. The interdisciplinary model brought together health and education professionals, teacher aides, and the community, with the school being the lead agency. However,…

  3. Community Involvement in TB Research

    NARCIS (Netherlands)

    M. van der Werf (Marloes); S.G. Heumann (Silke); E.M.H. Mitchell

    2011-01-01

    textabstractWhile communities at risk have been both drivers and partners in HIV research, their important role in TB research is yet to be fully realized. Involvement of communities in tuberculosis care and prevention is currently on the international agenda. This creates opportunities and

  4. Mapping earthworm communities in Europe

    DEFF Research Database (Denmark)

    Rutgers, Michiel; Orgiazzi, Alberto; Gardi, Ciro

    Existing data sets on earthworm communities in Europe were collected, harmonized, modelled and depicted on a soil biodiversity map of Europe. Digital Soil Mapping was applied using multiple regressions relating relatively low density earthworm community data to soil characteristics, land use...

  5. What's Pragmatic about Community Organizing?

    Science.gov (United States)

    Abowitz, Kathleen Knight

    2010-01-01

    In the last decade, educational researchers and scholars have turned new attention to the theory and practice of community organizing as a method for addressing education injustices. While there are diverse traditions of community organizing work, by far the most influential model in US contexts is that of Saul Alinsky, whose "Rules for Radicals"…

  6. Community, Democracy, and Neighborhood News.

    Science.gov (United States)

    Hindman, Elizabeth Blanks

    1998-01-01

    Contributes to scholarship on democracy, community, and journalism by examining the interplay between communication, democracy, and community at an inner-city neighborhood newspaper. Concludes that, through its focus on neighborhood culture, acknowledgment of conflict, and attempts to provide a forum for the neighborhood's self-definition, the…

  7. Microbial communities in blueberry soils

    Science.gov (United States)

    Microbial communities thrive in the soil of the plant root zone and it is clear that these communities play a role in plant health. Although blueberry fields can be productive for decades, yields are sometimes below expectations and fields that are replanted sometimes underperform and/or take too lo...

  8. Online Education in Community Colleges

    Science.gov (United States)

    Cejda, Brent

    2010-01-01

    This chapter explores the tremendous growth in the use of the Internet to deliver distance education at community colleges. The author examines various definitions of online education, including the types of courses, programs, and degrees available and the types of community colleges that offer greater amounts of online programming. Considerations…

  9. Underrepresented communities: including the Portuguese ...

    African Journals Online (AJOL)

    This research article emanates from a doctoral study which investigated the potential inclusion of the records generated by South African Portuguese community-based organisations into a workable archival collecting initiative of the community. The specific purpose of this article is to report on the current status of ...

  10. The Community Psychology Evaluation Nexus

    Science.gov (United States)

    Sheldon, Jeffrey A.; Wolfe, Susan M.

    2015-01-01

    In 2012, the American Evaluation Association (AEA) added community psychology (CP) to its roster of topical interests groups (TIG). One of the highlights of the CP TIG program at the 2012 AEA Conference and the genesis of this "American Journal of Evaluation" Forum was a panel of accomplished community psychologists and evaluation…

  11. A Professional Learning Community Approach

    African Journals Online (AJOL)

    This paper provides insights into how Life Sciences teachers in the Eastern Cape can be supported through professional learning communities (PLCs) as a potential approach to enhancing their biodiversity knowledge. PLCs are communities that provide the setting and necessary support for groups of classroom teachers to ...

  12. Community Orientation and Media Use.

    Science.gov (United States)

    Neuwirth, Kurt; And Others

    1989-01-01

    Examines the relationship among media use, participation in local shopping and leisure activities, and orientation toward the local community. Reexamines Robert Merton's Cosmopolitan scale, finding it to have both localite (exclusively local orientation) and cosmopolite (orientation to events outside the local community) dimensions. (MM)

  13. Introduction: Diverse Perspectives on Community

    Science.gov (United States)

    Jakes J. Pamela; Dorothy Anderson

    2000-01-01

    A glance through the table of contents of any social science journal illustrates that social science disciplines define community quite differently. For example, geographers emphasize spatial aspects, economists emphasize work and markets, and sociologists emphasize social interactions and networks in their definitions of communities. As a scientific concept,...

  14. Inroduction: diverse perspectives on community

    Science.gov (United States)

    Pamela J. Jakes; Dorothy Anderson

    2000-01-01

    A glance through the table of contents of any social science journal illustrates that social science disciplines define community quite differently. For example, geographers emphasize spatial aspects, economists emphasize work and markets, and sociologists emphasize social interactions and networks in their definitions of communities. As a scientific concept,...

  15. Community Music in Cultural Policy

    NARCIS (Netherlands)

    van den Hoogen, Quirijn; Bisschop Boele, Evert; Bartleet, Brydie-Leigh; Higgins, Lee

    2018-01-01

    Community Music presents a contested field. Its art status, its methods and its effects all are under scrutiny as the various actors involved in community music practices frequently have very different backgrounds and different objectives. Aesthetic intentions, social objectives and economic

  16. Healthy School Communities in Canada

    Science.gov (United States)

    Bassett-Gunter, Rebecca; Yessis, Jennifer; Manske, Steve; Gleddie, Doug

    2016-01-01

    Background and context: Healthy school communities aim to optimise student health and educational achievement. Various models, terms and resources have been used to describe healthy school communities. Policy makers and practitioners have reported confusion around many of the key concepts involved because of the varying models and terms.…

  17. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    care policy which was intended to make health care which of the two alternative methods of health care available to individuals and families in the financing options of free health or DRF was community at very little or no cost at all. However, preferred by the community members within most health facilities would appear to ...

  18. Global Journal of Community Medicine

    African Journals Online (AJOL)

    Global Journal of Community Medicine is aimed at promoting research in all areas of community or public health. It addresses issues of primary and tertiary health care. It deals with problems and solutions of health problems at the grassroots and daily livings. Visit the Global Journal Series website here: ...

  19. Democratic Leadership for Community Schools

    Science.gov (United States)

    Ruffin, Verna D.; Brooks, Jeffrey S.

    2010-01-01

    Because educators continue to face challenges when seeking to educate all children, there is a growing recognition that schools must work with communities to maximize their collective educational potential (Murphy, Beck, Crawford, Hodges, & McGauphy, 2001). Although community schools are still in the emergent stages of development, their emphasis…

  20. Positive feedback in species communities

    NARCIS (Netherlands)

    Gerla, D.J.

    2012-01-01

    Sometimes the eventual population densities in a species community depend on the initial densities or the arrival times of species. If arrival times determine species composition, a priority effect has occurred. Priority effects may occur if the species community exhibits alternative stable states

  1. Community pharmacy practice in Pakistan

    Directory of Open Access Journals (Sweden)

    Nousheen Aslam

    2012-01-01

    Conclusion: This study concludes that the current status of community pharmacy practice is below par. There is a need to involve more pharmacists at community level and develop awareness programs to counter patients′ routine drug issues and reducing the burden of disease from society.

  2. Iowa Community Colleges Accounting Manual.

    Science.gov (United States)

    Iowa State Dept. of Education, Des Moines. Div. of Community Colleges and Workforce Preparation.

    This document describes account classifications and definitions for the accounting system of the Iowa community colleges. In view of the objectives of the accounting system, it is necessary to segregate the assets of the community college according to its source and intended use. Additionally, the accounting system should provide for accounting by…

  3. Tenure and America's Community Colleges

    Science.gov (United States)

    DiMaria, Frank

    2012-01-01

    America's colleges and universities have been moving slowly but steadily away from tenure over the past decade. The American Federation of Teachers reports that community colleges have seen a 22% increase in the number of instructional staff between 1997 and 2007. During that time, the percentage of community college faculty that were full-time…

  4. Probing community nurses' professional basis

    DEFF Research Database (Denmark)

    Schaarup, Clara; Pape-Haugaard, Louise; Jensen, Merete Hartun

    2017-01-01

    Complicated and long-lasting wound care of diabetic foot ulcers are moving from specialists in wound care at hospitals towards community nurses without specialist diabetic foot ulcer wound care knowledge. The aim of the study is to elucidate community nurses' professional basis for treating...... diabetic foot ulcers. A situational case study design was adopted in an archetypical Danish community nursing setting. Experience is a crucial component in the community nurses' professional basis for treating diabetic foot ulcers. Peer-to-peer training is the prevailing way to learn about diabetic foot...... ulcer, however, this contributes to the risk of low evidence-based practice. Finally, a frequent behaviour among the community nurses is to consult colleagues before treating the diabetic foot ulcers....

  5. Coalfield communities and their environment

    Energy Technology Data Exchange (ETDEWEB)

    Parkinson, E

    1985-01-01

    Three main issues threaten the future of the coalfield communities: the coal industry is creating new capacity as the demand for coal slumps against predicted growth; the western democracies in general, and Britain in particular, are undergoing an economic restructuring under a financial management strategy which yields high levels of unemployment; the coalfield communities live in environments determined by the nature and history of their own local coal industry. The paper considers the effects of these issues on the coalfield communities. Topics covered are: the coalfield communities; opportunities to work; land use planning and the coal industry; spoil disposal; land reclamation; access; housing; tourism and leisure; open cast mining; coalfield community action zones; the financial scene.

  6. Do we need community geriatrics?

    LENUS (Irish Health Repository)

    O'Hanlon, S

    2012-01-30

    Community geriatrics has evolved as a specific aspect of geriatric medicine in the UK. In Ireland there is uncertainty as to how it should be planned. This is the first national survey of consultants, specialist registrars and general practitioners to seek their opinions. Most consultants and GPs reported already having a community aspect to their current practice, e.g. nursing home visits or community hospital visits, whereas most SpRs did not. Forty three of 62 respondents (69%) agreed that there is a need for community geriatricians and that there should be integration with hospital medicine. Fifty seven of 62 respondents (92%) felt that there would be a beneficial effect on GP services, though some expressed concern about work overlap. Thirteen of the 25 SpRs (52%) in training hoped to begin practice in community geriatrics in the future.

  7. Community Capacity Building for Health

    Directory of Open Access Journals (Sweden)

    Martha Traverso-Yepez

    2012-05-01

    Full Text Available There is a great deal of literature examining the benefits and relevance of community participation and community capacity building in health promotion and disease prevention endeavors. Academic literature embracing principles and commitment to community participation in health promotion practices often neglects the complexities involved and the flexibility required to work within this approach. This article addresses some of these challenges through a case study of two projects funded by Provincial Wellness Grants in Newfoundland and Labrador, a province in Canada with a strong tradition of community ties and support systems. In addition to addressing the unique circumstances of the community groups, this research allowed the authors to examine the situational context and power relations involved in the provision of services as well as the particular forms of subjectivity and citizenship that the institutional practices support. Recognizing this complex interdependency is an important step in creating more effective intervention practices.

  8. Community attitudes toward nuclear plants

    International Nuclear Information System (INIS)

    Peelle, E.

    1982-01-01

    Among the many effects of the accident at Three Mile Island are impacts upon other communities that currently host nuclear-power reactors. Because studies on communities' reactions not immediately available, this chapter reviews existing studies and speculates about possible effects. The patterns and variations in impacts on and responses of nuclear host communities have been the subject of studies at Oak Ridge National Laboratory (Oak Ridge, Tennessee) since 1972. This essay presents results from four post-licensing studies of host communities - Plymouth, Massachusetts, and Waterford, Connecticut (PL-1), and Brunswick, North Carolina, and Appling-Toombs counties, Georgia (PL-2) - along with case study and attitude survey information from two additional communities in which reactors are under construction: Hartsville, Tennessee, and Cherokee County, South Carolina. Differences and similarities between the sites have been assessed in terms of differences in input and social structure; factors affecting the generally favorable attitudes toward local nuclear plants are discussed

  9. Paradoxes unbounded: Practising community making

    Directory of Open Access Journals (Sweden)

    Tess Maginess

    2011-10-01

    Full Text Available The first section of this paper is a discussion of the paradoxes contained in definitionsof the word 'community' and deliberately foregrounds and makes problematicconflicting meanings before arguing for a third definition and practice of community.This third definition and practice celebrates and even transcends contradictions withinan active learning model of education in the community, aimed at tackling inequalityand prejudice. The second section offers an autocritical narrative account of aneducation in the community project that illustrates how such a practice of communitymaking can be achieved within an educational framework in which pupil is teacher andteacher is pupil and in which an imaginative, creative approach is deployed toconstruct a community making practice. The paper draws on understandings fromcommunity development, inclusive and creative education, emancipatory actionresearch, postcolonial and post-structuralist theory.

  10. Community-acquired pneumonia

    International Nuclear Information System (INIS)

    Poetter-Lang, S.; Herold, C.J.

    2017-01-01

    The diagnosis of community-acquired pneumonia (CAP) is often not possible based only on the clinical symptoms and biochemical parameters. For every patient with the suspicion of CAP, a chest radiograph in two planes should be carried out. Additionally, a risk stratification for the decision between outpatient therapy or hospitalization is recommended. Based on the evaluation of the different radiological patterns as well as their extent and distribution, a rough allocation to so-called pathogen groups as well as a differentiation between viral and bacterial infections are possible; however, because different pathogens cause different patterns an accurate correlation is not feasible by relying purely on imaging. The radiological findings serve as proof or exclusion of pneumonia and can also be used to evaluate the extent of the disease (e.g. monolobular, multilobular, unilateral or bilateral). In cases of prolonged disease, suspicion of complications (e.g. pleural effusion or empyema, necrotizing pneumonia or abscess) or comorbid conditions (e.g. underlying pulmonary or mediastinal diseases) computed tomography is an important diagnostic tool in addition to chest radiography. Ultrasound is often used to diagnose pleural processes (e.g. parapneumonic effusion or pleural empyema). (orig.) [de

  11. From Community to Meta-Community Mental Health Care

    Directory of Open Access Journals (Sweden)

    Nick Bouras

    2018-04-01

    Full Text Available Since the 1960s, we have witnessed the development and growth of community mental health care that continues to dominate mental health policy and practice. Several high-income countries have implemented community mental health care programmes but for many others, including mostly low- and middle-income countries, it remains an aspiration. Although community mental health care has been positive for many service users, it has also had severe shortcomings. Expectations that it would lead to fuller social integration have not been fulfilled and many service users remain secluded in sheltered or custodial environments with limited social contacts and no prospect of work. Others receive little or no service at all. In today’s complex landscape of increasingly specialised services for people with mental health problems, the number of possible interfaces between services is increasing. Together with existing uneven financing systems and a context of constant change, these interfaces are challenging us to develop effective care pathways adjusted to the needs of service users and their carers. This discussion paper reviews the developments in community mental health care over the recent years and puts forward the concept of “Meta-Community Mental Health Care”. “Meta-Community Mental Health Care” embraces pluralism in understanding and treating psychiatric disorders, acknowledges the complexities of community provision, and reflects the realities and needs of the current era of care.

  12. Saraniyadhamma Community knowledge Incubator area

    Directory of Open Access Journals (Sweden)

    Siripong Arundechachai

    2017-03-01

    Full Text Available The purposes of this research were to 1 study the situation of the community knowledge incubator area at the past to the present time in Banhad,Tambon banhad, Amphoe banhad Changwat KhonKaen, 2 study guidelines Buddhadhamma “Saraniyadhamma” revised by Community knowledge application Banhad, Tambon banhad, Amphoe banhad Changwat KhonKaen, 3 study workflow of Saraniyadhamma that led to the creation of the network community knowledge incubator area together with another community. The target groups used in this research of the purposive sampling family farmers of 10, in Tambon banhad,Amphoe banhad Changwat KhonKaen. the Qualitative research.was used in this Study The results showed that 1 diversing issues in the Community live action of the relationships or occupations experience can be passed down, as well as the risk of loss the relationships between the people and people, people and supernatural. After people and nature lost in the community, but thay Continue to Perform, because community has strengths given the importance of all, to themselves, to others, generous, generosity, mounting traditions, Led to the creation Community Knowledge Incubator 2 adopting Buddhism’s “Saraniyadhamma 6” that applied to community Knowledge Incubator by giving to make immunity community. Strong The six fetures, were Principle 1: Metta-kayakamma, feature on sacrifiction, unity and synergy. Principle 2: Metta-manokamma, feature on mercifulness, collective sacrification. Principle 3: Metta-kayakamma, feature on good things, speak well, good action. Principle 4: Sadharana-bhogi, feature on humane society, mutual respect. Principle 5 Sila-samannata, feature on, follow the rules of society. Principle 5 Metta-manokamma feature on rationality, listening to the opinion of others. It found that there were process-driven learning and following six rules of saraniyadhamma, and immunity system, risk Decoupled. 3 Networks Saraniyadhamma learnt together with other

  13. Immigrant-Host Community Relations in Malawi's Community Based ...

    African Journals Online (AJOL)

    government sponsored settlement schemes in Zimbabwe, for example, are viewed as ... diversity of community development projects and state provided public ..... Development Project in Malawi: case studies of beneficiary groups in Machinga ...

  14. 78 FR 13350 - Proposed Collection; Comment Request Healthy Communities Study: How Communities Shape Children's...

    Science.gov (United States)

    2013-02-27

    ... community-based initiatives; community characteristics (e.g., school environment); measurements of children... used for the development of future research initiatives targeting childhood obesity. Frequency of... Request Healthy Communities Study: How Communities Shape Children's Health (HCS) Summary: Under the...

  15. 76 FR 59706 - Proposed Collection; Comment Request; Healthy Communities Study: How Communities Shape Children's...

    Science.gov (United States)

    2011-09-27

    ... published in scientific journals and will be used for the development of future research initiatives... Request; Healthy Communities Study: How Communities Shape Children's Health (HCS) SUMMARY: Under the... control number. Proposed Collection: Title: Healthy Communities Study: How Communities Shape Children's...

  16. Uranium in the Near-shore Aquatic Food Chain: Studies on Periphyton and Asian Clams

    Energy Technology Data Exchange (ETDEWEB)

    Bunn, Amoret L.; Miley, Terri B.; Eslinger, Paul W.; Brandt, Charles A.; Napier, Bruce A.

    2007-12-31

    The benthic aquatic organisms in the near-shore environment of the Columbia River are the first biological receptors that can be exposed to groundwater contaminants coming from the U.S. Department of Energy's Hanford Site. The primary contaminant of concern in the former nuclear fuels processing area at the Site, known as the 300 Area, is uranium. Currently, there are no national clean up criteria for uranium and ecological receptors. This report summarizes efforts to characterize biological uptake of uranium in the food chain of the benthic aquatic organisms and provide information to be used in future assessments of uranium and the ecosystem.

  17. Ecological consequences of antibiotic exposure to periphyton in naturally colonizing stream mesocosms

    Science.gov (United States)

    Tetracycline and its derivatives are extensively used human and animal antibiotics, and enter stream ecosystems via point and non-point sources. Laboratory studies indicate that microbial organisms are more sensitive to antibiotics than invertebrates or fish, and may indicate t...

  18. Ecology of periphyton in a meltwater stream ecosystem in the maritime Antarctica

    Czech Academy of Sciences Publication Activity Database

    Elster, Josef; Komárek, O.

    2003-01-01

    Roč. 15, č. 2 (2003), s. 189-201 ISSN 0954-1020 R&D Projects: GA ČR GA205/94/0156; GA MŠk ME 576; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6005908 Keywords : environmental parameters * King George Island * meltwater streams Subject RIV: EF - Botanics Impact factor: 1.265, year: 2003

  19. Comparative studies of the nitrogen metabolism of phytoplankton and periphyton in oligotrophic lakes

    International Nuclear Information System (INIS)

    Axler, R.P.; Goldman, C.R.; Reuter, J.E.; Loeb, S.L.; Priscu, J.C.; Carlton, R.G.

    1983-01-01

    This report presents the preliminary data of limnological research at the meso-oligotrophic Castle Lake, CA and at the ultratrophic Lake Tahoe, CA-NEV, USA, during 1980 to 1981. The areas of study were effects of nutrients enrichment and deficiency on primary producers; nitrogen cycling and nitrogen metabolism of benthic and planktonic algae and whole-epilimnion enrichment with ammonium nitrate. Tracer techniques using 14 C- and 15 N-labelled compounds were employed in the study

  20. Uranium in the Near-shore Aquatic Food Chain: Studies on Periphyton and Asian Clams

    International Nuclear Information System (INIS)

    Bunn, Amoret L.; Miley, Terri B.; Eslinger, Paul W.; Brandt, Charles A.; Napier, Bruce A.

    2007-01-01

    The benthic aquatic organisms in the near-shore environment of the Columbia River are the first biological receptors that can be exposed to groundwater contaminants coming from the U.S. Department of Energy's Hanford Site. The primary contaminant of concern in the former nuclear fuels processing area at the Site, known as the 300 Area, is uranium. Currently, there are no national clean up criteria for uranium and ecological receptors. This report summarizes efforts to characterize biological uptake of uranium in the food chain of the benthic aquatic organisms and provide information to be used in future assessments of uranium and the ecosystem.

  1. Challenge of superfund community relations

    International Nuclear Information System (INIS)

    Goldman, N.J.

    1991-01-01

    Conducting a community relations effort in a community which is home to a Superfund site is a formidable challenge. Any education press, however appropriate, quickly falls victim to doubt, mistrust of fears of the very public intended to be served by the effort. While each site is uniquely different, the issues raised by affected communities in one part of the country are strikingly similar to those raised in other parts. Those most involved must join those most affected in seeking meaningful solutions and in building the trust that is so vital in moving forward with Superfund

  2. Opinion Evolution in Closed Community

    Science.gov (United States)

    Sznajd-Weron, Katarzyna; Sznajd, Józef

    A simple Ising spin model which can describe a mechanism of making a decision in a closed community is proposed. It is shown via standard Monte Carlo simulations that very simple rules lead to rather complicated dynamics and to a power law in the decision time distribution. It is found that a closed community has to evolve either to a dictatorship or a stalemate state (inability to take any common decision). A common decision can be taken in a ``democratic way'' only by an open community.

  3. Systems biology of Microbial Communities

    Energy Technology Data Exchange (ETDEWEB)

    Navid, A; Ghim, C; Fenley, A; Yoon, S; Lee, S; Almaas, E

    2008-04-11

    Microbes exist naturally in a wide range of environments, spanning the extremes of high acidity and high temperature to soil and the ocean, in communities where their interactions are significant. We present a practical discussion of three different approaches for modeling microbial communities: rate equations, individual-based modeling, and population dynamics. We illustrate the approaches with detailed examples. Each approach is best fit to different levels of system representation, and they have different needs for detailed biological input. Thus, this set of approaches is able to address the operation and function of microbial communities on a wide range of organizational levels.

  4. Reconsidering Community-based Retailing

    OpenAIRE

    Maughan, Rebecca; O'Driscoll, Aidan

    2012-01-01

    One of the areas with great potential for economic, social and environmental benefit is community-based retailing. The concept of community based retailing can incorporate a number of different tenets. We suggest that it is retailing that is based close to the community it serves, usually within the town or village centre rather than out-of-town locations, and which is composed of a diverse range of small and medium sized business that are often independently or co-operatively owned. These co...

  5. Innovative Partnerships Assist Community College Computing Programs.

    Science.gov (United States)

    O'Banion, Terry

    1987-01-01

    Relates efforts of major corporations in providing assistance to community college computing programs. Explains the goals of the League for Innovation in the Community College, a consortium of 19 community colleges, and cites examples of collaborative projects. (ML)

  6. Community Seismic Network (CSN)

    Science.gov (United States)

    Clayton, R. W.; Heaton, T. H.; Kohler, M. D.; Cheng, M.; Guy, R.; Chandy, M.; Krause, A.; Bunn, J.; Olson, M.; Faulkner, M.; Liu, A.; Strand, L.

    2012-12-01

    We report on developments in sensor connectivity, architecture, and data fusion algorithms executed in Cloud computing systems in the Community Seismic Network (CSN), a network of low-cost sensors housed in homes and offices by volunteers in the Pasadena, CA area. The network has over 200 sensors continuously reporting anomalies in local acceleration through the Internet to a Cloud computing service (the Google App Engine) that continually fuses sensor data to rapidly detect shaking from earthquakes. The Cloud computing system consists of data centers geographically distributed across the continent and is likely to be resilient even during earthquakes and other local disasters. The region of Southern California is partitioned in a multi-grid style into sets of telescoping cells called geocells. Data streams from sensors within a geocell are fused to detect anomalous shaking across the geocell. Temporal spatial patterns across geocells are used to detect anomalies across regions. The challenge is to detect earthquakes rapidly with an extremely low false positive rate. We report on two data fusion algorithms, one that tessellates the surface so as to fuse data from a large region around Pasadena and the other, which uses a standard tessellation of equal-sized cells. Since September 2011, the network has successfully detected earthquakes of magnitude 2.5 or higher within 40 Km of Pasadena. In addition to the standard USB device, which connects to the host's computer, we have developed a stand-alone sensor that directly connects to the internet via Ethernet or wifi. This bypasses security concerns that some companies have with the USB-connected devices, and allows for 24/7 monitoring at sites that would otherwise shut down their computers after working hours. In buildings we use the sensors to model the behavior of the structures during weak events in order to understand how they will perform during strong events. Visualization models of instrumented buildings ranging

  7. Community participation in disease control.

    Science.gov (United States)

    Bermejo, A; Bekui, A

    1993-05-01

    The main determinants of community participation in disease control programmes are identified and a framework with eleven variables is developed. Attention is drawn to the political background, community characteristics, the managerial capacity of the provider and the epidemiology of the disease. The framework is designed to guide health professionals in the systematic assessment and monitoring of participation in disease control programmes. Analysis of the Ghanaian Guinea Worm Eradication Programme and the Nicaraguan Tuberculosis Control Programme are presented as case studies. They show that political support does not guarantee community participation in disease control programmes and stress the importance of other determinants such as commitment to PHC, intersectoral coordination, the project approach and human resources. The relevance of the epidemiology of the disease in determining what degree of community participation will be most effective is highlighted by the case studies.

  8. Community Detection for Large Graphs

    KAUST Repository

    Peng, Chengbin; Kolda, Tamara G.; Pinar, Ali; Zhang, Zhihua; Keyes, David E.

    2014-01-01

    Many real world networks have inherent community structures, including social networks, transportation networks, biological networks, etc. For large scale networks with millions or billions of nodes in real-world applications, accelerating current

  9. International Journal of Community Research

    African Journals Online (AJOL)

    : 2384 - 6828] is a peer reviewed journal publication of Anthonio Research Center. IJCR publishes research articles, review articles, short reports and commentaries that are community-based or inter and intra-cultural based. IJCR also accepts ...

  10. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    Journal of Community Medicine and Primary Health Care. ... Ladoke Akintola University of Technology, PMB 4400, Osogbo, Osun State. ... weak management and poor adherence to the basic infrastructure e.g. primary, secondary and tertiary.

  11. Community Culture and the Environment

    Science.gov (United States)

    The Guide explores the concepts of community and culture and provides tools for identifying, assessing and working cooperatively within the social dynamics and local values connected to environmental protection.

  12. Being participated: a community approach

    CSIR Research Space (South Africa)

    Winschiers-Theophilus, H

    2010-01-01

    Full Text Available obvious throughout the design experiences within our community project. Supported by a theoretical framework we reflect upon current participatory design practices. We intend to inspire and refine participatory design concepts and methods beyond...

  13. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    adedamla

    Quarry industry has become a major means of livelihood in Ebonyi state, but insufficient data exists on their operations ... of Dust Mask among Crushers of Selected Quarry (Crushed ... Journal of Community Medicine and Primary Health Care.

  14. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    -dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we......Many terrestrial plant canopies regulate spatial patterns in leaf density and leaf inclination to distribute light evenly between the photosynthetic tissue and to optimize light utilization efficiency. Sessile aquatic macrophytes, however, cannot maintain the same well-defined three...... was markedly enhanced by a vertical orientation of thalli when absorptance and community density were both high. This result implies that aquatic macrophytes of high thallus absorptance and community density exposed to high light are limited in attaining high gross production rates because of their inability...

  15. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    Department of Epidemiology and Community Health, University of Ilorin, Ilorin, Nigeria .... exercise. All pupils in the selected school later done under the light ..... increased the likelihood of intestinal parasitic of Ilechukwu et al in which a ...

  16. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    ajiboro

    3Department of Community and Primary Health Care, College of Medicine, University of Lagos, Idiaraba, ... Some of the participants (45.3%) carry out physical exercises such as walking ..... hypertension, continuous effective management of.

  17. Storage Tank Legionella and Community

    Data.gov (United States)

    U.S. Environmental Protection Agency — Storage Tank Legionella and Community. This dataset is associated with the following publication: Qin, K., I. Struewing, J. Santodomingo, D. Lytle, and J. Lu....

  18. & PRIMARY HEALTH CARE COMMUNITY MEDICINE

    African Journals Online (AJOL)

    community, workplace, markets and healthcare effect of attrition giving approximately 200 and. 12 setting. ..... of women and 94% of men had heard about HIV. ... barriers to HIV prevention, HIV Counseling and. 26 ... gave a human face to HIV.

  19. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    ajiboro

    Work Profile of Community Health Extension Workers in Cross. River State and ... reasons. In some countries they were to meet shortages in health manpower. In other ... Life expectancy is 51 years; maternal mortality and workers were ...

  20. Community Governance and Vocational Education

    Science.gov (United States)

    Martasari, R.; Haryanti, R. H.; Susiloadi, P.

    2018-02-01

    Vocational education is required to create a design of education and training that is friendly and feasible for disabled people. The state has a responsibility for it, but with all the limitations, the state can not always be present. This article aims to analyze the capacity of community governance in passing vocational education for people with disabilities in Ponorogo, Indonesia. Articles are the results of research for approximately two years by using data collection techniques through interviews, documentation and observation. Source Triangulation with analysis technique using interactive model is used for data validation. The results show that there are two large capacities owned by Organisasi Sosial Rumah Kasih Sayang as community governance in conducting vocational education for the disabled person namely community credibility and community vigilance.

  1. The iSchool Community

    DEFF Research Database (Denmark)

    Bogers, Toine; Greifeneder, Elke

    2016-01-01

    the reviewer pool more representative of the iSchool community as a whole by including more women and more researchers from Asian institutions. Other recommendations are to improve the continuity of the reviewer pool and to provide clearer instructions to reviewers to ensure that written reviews explicitly...... cover all the aspects represented by the review scores. The results of our study provide the iSchool community with a descriptive analysis of its community and a better understanding of its review process.......A fair review process is essential to the success of any scientific conference. In this paper we present an analysis of the reviewing process of the 2014-2015 iConferences as well as a demographic analysis of the iConference community as a whole. The results show a clear need for making...

  2. Community energy self-reliance

    Science.gov (United States)

    1980-07-01

    Goals of a workshop/conference on community renewable energy systems are: (1) to encourage decentralization in attacking energy problems, (2) to show how renewable energy can meet community goals, (3) to present examples of successful projects, (4) to discuss the planning and management of renewable energy systems, (5) to identify sources of financial support, (6) to share legal strategies, and (7) to examine utility roles.

  3. Spatiotemporal Modeling of Community Risk

    Science.gov (United States)

    2016-03-01

    Ertugay, and Sebnem Duzgun, “Exploratory and Inferential Methods for Spatio-Temporal Analysis of Residential Fire Clustering in Urban Areas,” Fire ...response in communities.”26 In “Exploratory and Inferential Methods for Spatio-temporal Analysis of Residential Fire Clustering in Urban Areas,” Ceyhan...of fire resources spread across the community. Spatiotemporal modeling shows that actualized risk is dynamic and relatively patterned. Though

  4. Community care and social services.

    OpenAIRE

    Renwick, D.

    1996-01-01

    The aim of community care is to enable people with various types of disability to live in their own homes, rather than in institutions. This involves the provision of support and services at home by various agencies. After a critical report in 1986 identified problems with coordination and flexibility of community care services, the white paper Caring for People (1989) stated the government's aim to provide a "needs led," responsive range of services, promoting maximum independence of those w...

  5. Privatizing community animal health worker based veterinary ...

    African Journals Online (AJOL)

    Privatizing community animal health worker based veterinary services delivery system in West Kordofan, Southern Sudan; The needed roles of community animal health assistant (CAHA) and Pastoral unions.

  6. Community Concern on Environmental Conservation

    Science.gov (United States)

    Nugraha, Fajar Adie; Maryono

    2018-02-01

    Research on the relationship between humans and the environment is always very interesting to be studied. This paper is one of the studies of sustainable development in its implementation with the empowerment of society that comes from the community itself. So far, community studies related to development occasionally target the growth of the economic side only. Community study on the environment becomes an alternative choice, compared with human relationships with humans themselves, or humans with human needs themselves. The study of community development by looking at the environment can be a wise choice, where all activities of fulfilling human needs are always inseparable from the element of interaction with the environment. Community development that is based on the environment itself, will give a better impact, just solely. Various methods of learning human relationships. A community-based environmental assessment study can be an alternative choice to support a sustainable development mission, which is development that has a positive impact on the present and the future.

  7. Mountain Plant Community Sentinels: AWOL

    Science.gov (United States)

    Malanson, G. P.

    2017-12-01

    Mountain plant communities are thought to be sensitive to climate change. Because climatic gradients are steep on mountain slopes, the spatial response of plant communities to climate change should be compressed and easier to detect. These expectations have led to identifying mountain plant communities as sentinels for climate change. This idea has, however, been criticized. Two critiques, for alpine treeline and alpine tundra, are rehearsed and supplemented. The critique of alpine treeline as sentinel is bolstered with new model results on the confounding role of dispersal mechanisms and sensitivity to climatic volatility. In alpine tundra, for which background turnover rates have yet to be established, community composition may reflect environmental gradients only for extremes where effects of climate are most indirect. Both plant communities, while primarily determined by energy at broad scales, may respond to water as a proximate driver at local scales. These plant communities may not be in equilibrium with climate, and differently scaled time lags may mean that ongoing vegetation change may not signal ongoing climate change (or lack thereof). In both cases a double-whammy is created by scale dependence for time lags and for drivers leading to confusion, but these cases present opportunities for insights into basic ecology.

  8. A community approach to health.

    Science.gov (United States)

    Hagland, M

    1997-01-01

    Improving the health and well-being of a community may seem like a daunting task-particularly when you consider the vast number of factors that can influence the quality of life of a neighborhood or a region. It's not impossible, however, as six widely different communities across the U.S. are discovering. The Accelerating Community Transformation (ACT) project--now underway by The Healthcare Forum through a five-year, $5 million grant from pharmaceutical joint venture Astra Merck Inc.--is an innovative attempt to create real-life learning laboratories in communities as diverse as an inner-city neighborhood on the west side of Chicago; the small southern town of Aiken, S.C.: the semi-desert city of San Bernardino, Calif.; a corner of America's heartland where Missouri, Kansas. Nebraska and Iowa meet; the new town of Celebration, Fla.; and St. Louis, Mo. The goals: to evaluate and accelerate community-wide efforts that result in healthier, more desirable places for people to live, work and play; to build community capacity; and to achieve measurable improved health and quality of life outcomes.

  9. Innovations in community physiotherapy

    Directory of Open Access Journals (Sweden)

    M. Ellangovin

    2010-09-01

    Full Text Available In the last 35 years, Bangladesh has produced only 415 physiotherapists to meet the demands of a total population of 150 million. Most of them practice in the capital city of Dhaka because of better business prospects. The need to formulate an innovative strategy to meet the huge demand is obvious.According to a World Bank report (2005, 44% (poor and 33% (very poor people approach local pharmacists or medicine sellers for their ailments due to poor accessibility to healthcare facilities and also to avoid consultation fees. Due to scarcity in the number of professionals, community physiotherapists have become popular with rural patients. They use innovative treatment approaches, which combines traditional Physiotherapy and ancient Ayurvedic massage. Targeting equitable access to all, Gonoshasthaya Kendra (GK has its own health insurance policy. The fee is determined by the socio-economic status of the patient. Experienced paramedics are now able to administer treatment without direct supervision all the time. The number of patients seen by them is multiplying at a fascinating rate every year due to the growing recognition of their work. Gonoshasthaya Kendra (GK was established in 1972 and provides primary health care to a rural population of over 1.08 million across 629 villages in Bangladesh. The strategies and methods adopted by Gonoshasthaya Kendra in bridging the gap and promoting community physiotherapy by training health workers or “paramedics” in Bangladesh, has been successful. Even though training of many more paramedics is required, success is guaranteed.Au cours de ces 35 dernières années, le Bangladesh a formé uniquement 415 kinésithérapeutes pour une population totale de 150 millions de personnes. La plupart d’entre eux exercent dans la capitale, Dhaka, où les perspectives de travail sont les meilleures. La mise en place d’une stratégie innovante est par conséquent nécessaire pour répondre à la forte demande

  10. Corporate Philanthropy Toward Community Health Improvement in Manufacturing Communities.

    Science.gov (United States)

    McHugh, Megan; Farley, Diane; Maechling, Claude R; Dunlop, Dorothy D; French, Dustin D; Holl, Jane L

    2018-06-01

    Virtually all large employers engage in corporate philanthropy, but little is known about the extent to which it is directed toward improving community health. We conducted in-depth interviews with leaders of corporate philanthropy from 13 of the largest manufacturing companies in the US to understand how giving decisions were made, the extent to which funding was directed towards improving community health, and whether companies coordinate with local public health agencies. We found that corporate giving was sizable and directed towards communities in which the manufacturers have a large presence. Giving was aligned with the social determinants of health (i.e., aimed at improving economic stability, the neighborhood and physical environment, education, food security and nutrition, the community and social context, and the health care system). However, improving public health was not often cited as a goal of corporate giving, and coordination with public health agencies was limited. Our results suggest that there may be opportunities for public health agencies to help guide corporate philanthropy, particularly by sharing community-level data and offering their measurement and evaluation expertise.

  11. Contextual community prevention theory: building interventions with community agency collaboration.

    Science.gov (United States)

    Morales, Eduardo S

    2009-11-01

    Translation from research to practice faces numerous problems that include replicating effectiveness, fidelity to the protocol and processes, and adaptations to different types of target populations. Working collaboratively with existing service providers can speed up the time for development and can ease the implementation of empirical randomized trials. Contextual community prevention theory is an innovative approach that focuses on changing behaviors of community members by creating a visible institutional presence that draws and pulls the targeted population into the organization's activities and interventions. The result is an institution or organization within the community that provides a new active and dynamic context, engaging its community members into its activities, interventions, and functions. An HIV prevention program developed collaboratively from the ground up for Latino gay/bisexual men is presented. Results from the program evaluation efforts across the years suggest promise for testing its efficacy through a randomized trial. HIV prevention efforts need to develop dynamic support systems within communities where these men have ownership, have control, and feel safe; otherwise HIV infection rates in this population will increase. Copyright 2009 by the American Psychological Association

  12. Community empowerment and community cohesion: parallel agendas for community building in England?

    Directory of Open Access Journals (Sweden)

    Marjorie Mayo

    2009-02-01

    Full Text Available Community empowerment and community capacity building have been central to government agendas in Britain over the past decade. Agendas for tackling the so-called ‘War on Terrorism’ and promoting community cohesion have become increasingly significant in addition, especially since the bombings in London in 2005. This article focuses upon the current gap between these differing agendas. This is particularly relevant in an era of increasing globalisation, with considerable debate on the impact of migration, and anxieties about previous approaches to multiculturalism that have been the subject of growing criticism. Having set out these gaps in public policy and research in this field, the article examines the evidence from research, including 100 interviews together with focus groups conducted in three localities in England, identifying the problems, in terms of the lack of engagement of ‘new communities’ and in terms of the potential tensions within and between communities. There was, however, encouraging evidence that strategies were being developed to develop more inclusive, more democratically accountable and more effective forms of community engagement. The article concludes by summarising potential implications for building community cohesion and social solidarity.

  13. Evaluating Community-Based Participatory Research to Improve Community-Partnered Science and Community Health

    Science.gov (United States)

    Hicks, Sarah; Duran, Bonnie; Wallerstein, Nina; Avila, Magdalena; Belone, Lorenda; Lucero, Julie; Magarati, Maya; Mainer, Elana; Martin, Diane; Muhammad, Michael; Oetzel, John; Pearson, Cynthia; Sahota, Puneet; Simonds, Vanessa; Sussman, Andrew; Tafoya, Greg; Hat, Emily White

    2013-01-01

    Background Since 2007, the National Congress of American Indians (NCAI) Policy Research Center (PRC) has partnered with the Universities of New Mexico and Washington to study the science of community-based participatory research (CBPR). Our goal is to identify facilitators and barriers to effective community–academic partnerships in American Indian and other communities, which face health disparities. Objectives We have described herein the scientific design of our National Institutes of Health (NIH)-funded study (2009–2013) and lessons learned by having a strong community partner leading the research efforts. Methods The research team is implementing a mixed-methods study involving a survey of principal investigators (PIs) and partners across the nation and in-depth case studies of CBPR projects. Results We present preliminary findings on methods and measures for community-engaged research and eight lessons learned thus far regarding partnership evaluation, advisory councils, historical trust, research capacity development of community partner, advocacy, honoring each other, messaging, and funding. Conclusions Study methodologies and lessons learned can help community–academic research partnerships translate research in communities. PMID:22982842

  14. The environment and community relations

    International Nuclear Information System (INIS)

    Odogwu, E.C.

    1991-01-01

    Even though the petroleum industry in Nigeria has become the back bone of the Nigerian economy the relationship with the communities in the oil producing area is not all what it should be. There has been a significant shift in emphasis from the earlier peaceful and cordial relationship to the present more vocal sometimes violent relationship from a few communities who would like to see the operator held responsible for all environmental lapses of the past 50 years of oil operations in Nigeria. As the leading and most visible oil producer, we experience our share of strained relations in proportion to the size and extent of Shell's operations. Social unrest in the oil producing areas can be attributed to the frequent complaint by the communities of gross neglect by the oil producing companies and the Federal Government of Nigeria in the development of their areas. The community's feeling in that the level of compensation from environmental pollution is not sufficient to compensate the damage caused and this affects good community relations. Also, some communities feel that despite the taxes and royalties paid by multinational companies that, most of the petroleum profit from their God-given wealth is being taken away by such multinationals for development elsewhere. This feeling stems from the perceived glaring disparity between developments in the urban and rural areas where oil operations are carried out. This paper is an attempt to examine the social problems associated with oil exploration and production and the related environmental pollution therefrom and proffer suggestions on how such problems can be solved for good community relations

  15. Community detection using preference networks

    Science.gov (United States)

    Tasgin, Mursel; Bingol, Haluk O.

    2018-04-01

    Community detection is the task of identifying clusters or groups of nodes in a network where nodes within the same group are more connected with each other than with nodes in different groups. It has practical uses in identifying similar functions or roles of nodes in many biological, social and computer networks. With the availability of very large networks in recent years, performance and scalability of community detection algorithms become crucial, i.e. if time complexity of an algorithm is high, it cannot run on large networks. In this paper, we propose a new community detection algorithm, which has a local approach and is able to run on large networks. It has a simple and effective method; given a network, algorithm constructs a preference network of nodes where each node has a single outgoing edge showing its preferred node to be in the same community with. In such a preference network, each connected component is a community. Selection of the preferred node is performed using similarity based metrics of nodes. We use two alternatives for this purpose which can be calculated in 1-neighborhood of nodes, i.e. number of common neighbors of selector node and its neighbors and, the spread capability of neighbors around the selector node which is calculated by the gossip algorithm of Lind et.al. Our algorithm is tested on both computer generated LFR networks and real-life networks with ground-truth community structure. It can identify communities accurately in a fast way. It is local, scalable and suitable for distributed execution on large networks.

  16. Managing Communities – Mining MNEs’ Community Risk Management Practices

    DEFF Research Database (Denmark)

    Taarup Esbensen, Jacob

    This PhD reflects the effort to close a gap in the multinational enterprise (MNE) risk management literature on the identification and mitigation of risk arising from local communities. Small villages and towns that are situated geographically close to the MNEs’ place of operation have increasingly......-to-date information about mining MNE operations. This improved outreach has meant that mines have been closed due to conflicts with local communities and therefor a need had arisen for MNEs to implement management practices that can effectively mitigate these types of risks....... been identified as a source of risk (BSR, 2003; ICMM, 2015). The mining industry is one of the most exposed to risks from local communities, where there historically have been many conflicts between mine owners on one side and the people living close to the mine on the other (Godoy, 1985; Hoskin, 1912...

  17. The offshore benthic fish community

    Science.gov (United States)

    Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

    2014-01-01

    Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

  18. In-Drift Microbial Communities

    Energy Technology Data Exchange (ETDEWEB)

    D. Jolley

    2000-11-09

    As directed by written work direction (CRWMS M and O 1999f), Performance Assessment (PA) developed a model for microbial communities in the engineered barrier system (EBS) as documented here. The purpose of this model is to assist Performance Assessment and its Engineered Barrier Performance Section in modeling the geochemical environment within a potential repository drift for TSPA-SR/LA, thus allowing PA to provide a more detailed and complete near-field geochemical model and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). This model and its predecessor (the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document, CRWMS M and O 1998a) was developed to respond to the applicable KTIs. Additionally, because of the previous development of the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a), the M and O was effectively able to resolve a previous KTI concern regarding the effects of microbial processes on seepage and flow (NRC 1998). This document supercedes the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a). This document provides the conceptual framework of the revised in-drift microbial communities model to be used in subsequent performance assessment (PA) analyses.

  19. Profiting from innovative user communities

    DEFF Research Database (Denmark)

    Jeppesen, Lars Bo

    Modding - the modification of existing products by consumers - is increasingly exploited by manufacturers to enhance product development and sales. In the computer games industry modding has evolved into a development model in which users act as unpaid `complementors' to manufacturers' product pl......, a manufacturer can incorporate and commercialize the best complements found in the user communities. Keywords: innovation, modding, user communities, software platform, business model. JEL code(s): L21; L23; O31; O32...... platforms. This article explains how manufacturers can profit from their abilities to organize and facilitate a process of innovation by user communities and capture the value of the innovations produced in such communities. When managed strategically, two distinct, but not mutually exclusive business...... models appear from the production of user complements: firstly, a manufacturer can let the (free) user complements `drift' in the user communities, where they increase the value to consumers of owning the given platform and thus can be expected to generate increased platform sales, and secondly...

  20. In-Drift Microbial Communities

    International Nuclear Information System (INIS)

    Jolley, D.

    2000-01-01

    As directed by written work direction (CRWMS M and O 1999f), Performance Assessment (PA) developed a model for microbial communities in the engineered barrier system (EBS) as documented here. The purpose of this model is to assist Performance Assessment and its Engineered Barrier Performance Section in modeling the geochemical environment within a potential repository drift for TSPA-SR/LA, thus allowing PA to provide a more detailed and complete near-field geochemical model and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). This model and its predecessor (the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document, CRWMS M and O 1998a) was developed to respond to the applicable KTIs. Additionally, because of the previous development of the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a), the M and O was effectively able to resolve a previous KTI concern regarding the effects of microbial processes on seepage and flow (NRC 1998). This document supercedes the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a). This document provides the conceptual framework of the revised in-drift microbial communities model to be used in subsequent performance assessment (PA) analyses

  1. Experience Learning and Community Development

    Directory of Open Access Journals (Sweden)

    Nena Mijoč

    1996-12-01

    Full Text Available Research in the field of education, carried out in living and working environment, which has undergone so profound changes recently, is of extreme importance. In schools, courses and seminars, one cannot prepare him/herself for the changes as these are often so rapid that it is impossible to foresee them. Therefore, one can only learn by experience. In defining the term 'experience learning', the teoreticians vary greatly. In this paper, experience learning is understood as a process of learning taking part mainly outside the planned educational process and including an active and participative attitude towards environment and people. Original and direct experience can thus serve as a basis for gaining new comprehensions, for planning future activities as well as for a reinterpretation of the past experiences. Let us first mention the basic factors of successful experience learning, such as an individual's character features, possibilities for learning, learning atmosphere and positive stimulations. It has been estimated that local community can increase or decrease the possibilities for experience learning. However, the relation is active in other direction too: the more experience learning bas been asserted in a community, the greater its influence on social and cultural development of the community. On has to bear in mind that well-planned education for local community and stimulating sociocultural animation can facilitate the development of local community.

  2. Loneliness in senior housing communities.

    Science.gov (United States)

    Taylor, Harry Owen; Wang, Yi; Morrow-Howell, Nancy

    2018-05-23

    There are many studies on loneliness among community-dwelling older adults; however, there is limited research examining the extent and correlates of loneliness among older adults who reside in senior housing communities. This study examines the extent and correlates of loneliness in three public senior housing communities in the St. Louis area. Data for this project was collected with survey questionnaires with a total sample size of 148 respondents. Loneliness was measured using the Hughes 3-item loneliness scale. Additionally, the questionnaire contained measures on socio-demographics, health/mental health, social engagement, and social support. Missing data for the hierarchical multivariate regression models were imputed using multiple imputation methods. Results showed approximately 30.8% of the sample was not lonely, 42.7% was moderately lonely, and 26.6% was severely lonely. In the multivariate analyses, loneliness was primarily associated with depressive symptoms. Contrary to popular opinion, our study found the prevalence of loneliness was high in senior housing communities. Nevertheless, senior housing communities could be ideal locations for reducing loneliness among older adults. Interventions should focus on concomitantly addressing both an individual's loneliness and mental health.

  3. Diverse Perspectives on Inclusive School Communities

    Science.gov (United States)

    Tsokova, Diana; Tarr, Jane

    2012-01-01

    What is an inclusive school community? How do stakeholders perceive their roles and responsibilities towards inclusive school communities? How can school communities become more inclusive through engagement with individual perspectives? "Diverse Perspectives on Inclusive School Communities" captures and presents the voices of a wide…

  4. At the Intersection of College & Community

    Science.gov (United States)

    Pierce, Dennis

    2016-01-01

    By purchasing abandoned facilities and transforming them into vibrant hubs for culture and education, community colleges are fulfilling one of their key missions: revitalizing their communities. But these types of projects can be fraught with challenges as well. Here's how Austin Community College (Texas), Manchester Community College…

  5. Colleges and Communities: Increasing Local Capacity.

    Science.gov (United States)

    Baldwin, Fred D.

    2001-01-01

    Community colleges in Appalachia are helping boost local economies and expand educational opportunities through the national Rural Community College Initiative (RCCI). At the heart of RCCI is a nine-step strategic planning process in which a community group moves from vision to action. Kentucky's Southeast Community College has promoted…

  6. Teaching Community Organizing in a BSW Curriculum

    Science.gov (United States)

    Grodofsky, Merav Moshe; Bakun-Mazor, Hagar

    2012-01-01

    The article describes a community organizing course that was as dynamic as community organizing itself. By employing a combination of teaching approaches, community organizing philosophy, and pedagogical and andragogical techniques for student training, the course challenged students to discover their beliefs and the role of the community and the…

  7. Reducing Maternal Mortality by Strengthening Community Maternal ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    translated from Hausa to English language. Using a pre-determined coding framework, coding and thematic analyses were carried out on the qualitative data collected from the baseline. LGA. Community. Estimated. Community. Population. Community maternal support systems established. Community savings. Emergency.

  8. Community identities as visions for landscape change

    Science.gov (United States)

    William P. Stewart; Derek Liebert; Kevin W. Larkin

    2004-01-01

    Residents' felt senses of their community can play substantial roles in determining visions for landscape change. Community identities are often anchored in tangible environments and events of a community, and have the potential to serve as visions for landscape planning processes. Photo-elicitation is applied in this study to connect community-based meanings to...

  9. Community Psychology, Evaluation, and Social Critique

    Science.gov (United States)

    Miller, Robin Lin

    2015-01-01

    Community psychology blends psychological science, a community-level perspective on social issues, and a social justice orientation. Despite important difference between community psychology and program evaluation, program evaluation is a key component of many community psychologists' practice and holds a central place in my own. In this…

  10. Can AmeriCorps Build Communities?

    Science.gov (United States)

    Thomson, Ann Marie; Perry, James L.

    1998-01-01

    An examination of AmeriCorps in five communities focused on its impact on the capacity of local community-based organizations to achieve community goals. Most partner organizations were unable to build sufficient commitment for self-governance; few programs were designed to encourage collective goals. Getting things done in local communities may…

  11. Education in Aboriginal Communities: Dilemmas around Empowerment.

    Science.gov (United States)

    Taylor, Donald M.; And Others

    1993-01-01

    Sudden empowerment of Canadian Aboriginal communities has raised many dilemmas concerning community controlled education, including issues related to educational planning and decision making by inexperienced administrators, focusing educational goals on the community versus mainstream society, discontinuities between community and school culture,…

  12. Characterization of the Kootenai River Algae Community and Primary Productivity Before and After Experimental Nutrient Addition, 2004–2007 [Chapter 2, Kootenai River Algal Community Characterization, 2009 KTOI REPORT].

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charlie [Kootenai Tribe of Idaho; Bonners Ferry, ID; Anders, Paul [Cramer Fish Sciences; Moscow, ID; Shafii, Bahman [Statistical Consulting Services; Clarkston, WA

    2009-07-01

    , and a meandering reach. The study design included 14 sampling sites: an upstream, unimpounded reference site (KR-14), four control (non-fertilized) canyon sites downstream from Libby Dam, but upstream from nutrient addition (KR-10 through KR-13), two treatment sites referred to collectively as the nutrient addition zone (KR-9 and KR-9.1, located at and 5 km downstream from the nutrient addition site), two braided reach sites (KR-6 and KR-7), and four meander reach sites (KR-1 through KR-4). A series of qualitative evaluations and quantitative analyses were used to assess baseline conditions and effects of experimental nutrient addition treatments on chlorophyll, primary productivity, and taxonomic composition and metric arrays for the diatom and green algae communities. Insufficient density in the samples precluded analyses of bluegreen algae taxa and metrics for pre- and post-nutrient addition periods. Chlorophyll a concentration (mg/m{sup 2}), chlorophyll accrual rate (mg/m{sup 2}/30d), total chlorophyll concentration (chlorophyll a and b) (mg/m{sup 2}), and total chlorophyll accrual rate (mg/m{sup 2}/30d) were calculated. Algal taxa were identified and grouped by taxonomic order as Cyanophyta (blue-greens), Chlorophyta (greens), Bacillariophyta (diatoms), Chrysophyta (goldens), and dominant species from each sample site were identified. Algal densities (number/ml) in periphyton samples were calculated for each sample site and sampling date. Principal Component Analysis (PCA) was performed to reduce the dimension of diatom and algae data and to determine which taxonomic groups and metrics were contributing significantly to the observed variation. PCA analyses were tabulated to indicate eigenvalues, proportion, and cumulative percent variation, as well as eigenvectors (loadings) for each of the components. Biplot graphic displays of PCA axes were also generated to characterize the pattern and structure of the underlying variation. Taxonomic data and a series of

  13. Undiagnosed depression: A community diagnosis

    Directory of Open Access Journals (Sweden)

    Sharifa Z. Williams

    2017-12-01

    Full Text Available Many large provider networks are investing heavily in preventing disease within the communities that they serve. We explore the potential benefits and challenges associated with tackling depression at the community level using a unique dataset designed for one such provider network. The economic costs of having depression (increased medical care use, lower quality of life, and decreased workplace productivity are among the highest of any disease. Depression often goes undiagnosed, yet many believe that depression can be treated or prevented altogether. We explore the prevalence, distribution, economic burden, and the psychosocial and economic factors associated with undiagnosed depression in a lower-income neighborhood in northern Manhattan. Even using state-of-the art data to “diagnose” the risk factors within a community, it can be challenging for provider networks to act against such risk factors.

  14. Life span in online communities

    Science.gov (United States)

    Grabowski, A.; Kosiński, R. A.

    2010-12-01

    Recently online communities have attracted great interest and have become an important medium of information exchange between users. The aim of this work is to introduce a simple model of the evolution of online communities. This model describes (a) the time evolution of users’ activity in a web service, e.g., the time evolution of the number of online friends or written posts, (b) the time evolution of the degree distribution of a social network, and (c) the time evolution of the number of active users of a web service. In the second part of the paper we investigate the influence of the users’ lifespan (i.e., the total time in which they are active in an online community) on the process of rumor propagation in evolving social networks. Viral marketing is an important application of such method of information propagation.

  15. Community integration after burn injuries.

    Science.gov (United States)

    Esselman, P C; Ptacek, J T; Kowalske, K; Cromes, G F; deLateur, B J; Engrav, L H

    2001-01-01

    Evaluation of community integration is a meaningful outcome criterion after major burn injury. The Community Integration Questionnaire (CIQ) was administered to 463 individuals with major burn injuries. The CIQ results in Total, Home Integration, Social Integration, and Productivity scores. The purposes of this study were to determine change in CIQ scores over time and what burn injury and demographic factors predict CIQ scores. The CIQ scores did not change significantly from 6 to 12 to 24 months postburn injury. Home integration scores were best predicted by sex and living situation; Social Integration scores by marital status; and Productivity scores by functional outcome, burn severity, age, and preburn work factors. The data demonstrate that individuals with burn injuries have significant difficulties with community integration due to burn and nonburn related factors. CIQ scores did not improve over time but improvement may have occurred before the initial 6-month postburn injury follow-up in this study.

  16. Community Foresight for Urban Sustainability

    DEFF Research Database (Denmark)

    Mortensen, Jonas Egmose; Eames, Malcolm

    2011-01-01

    be necessary to deliver sustainability. In so doing, however, backcasting may run the risk of obscuring significant differences in current lived experience, negating alternative problem framings and normatively derived views of what constitutes sustainability. This paper reports an innovative UK attempt...... to develop an inclusive 'bottom-up' Community Foresight process for urban sustainability research. Unlike most backcasting studies, the methodology was initially grounded in an exploration of the community participants' current lived experience and understandings of sustainability. Given the particular...... purpose of the study the primary outcome from the work was structured around the articulation of a 'community-led' agenda for urban sustainability research, rather than an explicit normative vision and transition pathway. However, the methodology could easily be adapted for use in other contexts...

  17. Communities of the Future: Energy Programs for Livable Communities

    International Nuclear Information System (INIS)

    Jones, J. G.; Strawn, N.

    1999-01-01

    This document relates how several of the US Department of Energy's Office of Energy Efficiency and Renewable Energy (DOE/EERE) programs help communities across the nation deal with the issues of livability and sustainable growth. Highlights include background information on renewable energy technologies, some outstanding program anecdotes, and regional and Internet contact information

  18. Community theatre as instrument for community sensitisation and ...

    African Journals Online (AJOL)

    2016-03-28

    Mar 28, 2016 ... Agency (GIZ) in Cameroon, and is currently ... proposes strategies that could be deployed to effectively develop and establish ... traditional system, community theatre, environmental protection, sustainable economic development. ..... Some groups usually travel from place to place to carry out their activities,.

  19. Community theatre as instrument for community sensitisation and ...

    African Journals Online (AJOL)

    2016-03-28

    Mar 28, 2016 ... on their emotions and finally leaves them to take things as they are. In the same vein, Karl Marx .... number of people who attended community meetings, and this has motivated me to write other ..... “A Theory of Many Cultures.

  20. Community-Based Ecotourism: The Transformation of Local Community

    Directory of Open Access Journals (Sweden)

    Pookhao Nantira

    2014-01-01

    Full Text Available Community-based ecotourism (CBET is considered a sustainable form of tourism that improves the quality of life of hosts at the tourist destination. Scholars have yet to explore the long-term operation of CBET in relation to its effects on the local way of life. Consequently, the purpose of this paper is to examine the transformation of a local community due to the operation of CBET in relation to sociocultural, economic and environmental aspects. The findings reveal that the community encounters both positive and negative impacts of transformation. However, unintended impacts of the CBET operation lay embedded in the transformation of relationships among the community members. The study identifies that close relationships among the villagers has been initially transformed to loose relationships due to forgotten communal goals; CBET has transformed from being a conservation tool to being a business-oriented goal which causes conflicts of interest among local people and alters traditional social structure. The study also agrees with the notion of social exchange theory for villagers to enhance environmental sustainability, and proposes that slight inequalities of benefits received from CBET causes social transformation at the local level.

  1. Community-based recreational football

    DEFF Research Database (Denmark)

    Bruun, Ditte Marie; Bjerre, Eik; Krustrup, Peter

    2014-01-01

    is limited and the majority of prostate cancer survivors remain sedentary. Hence, novel approaches to evaluate and promote physical activity are warranted. This paper presents the rationale behind the delivery and evaluation of community-based recreational football offered in existing football clubs under...... the Danish Football Association to promote quality of life and physical activity adherence in prostate cancer survivors. The RE-AIM framework will be applied to evaluate the impact of the intervention including outcomes both at the individual and organizational level. By introducing community-based sport...

  2. Bullying in Virtual Learning Communities.

    Science.gov (United States)

    Nikiforos, Stefanos; Tzanavaris, Spyros; Kermanidis, Katia Lida

    2017-01-01

    Bullying through the internet has been investigated and analyzed mainly in the field of social media. In this paper, it is attempted to analyze bullying in the Virtual Learning Communities using Natural Language Processing (NLP) techniques, mainly in the context of sociocultural learning theories. Therefore four case studies took place. We aim to apply NLP techniques to speech analysis on communication data of online communities. Emphasis is given on qualitative data, taking into account the subjectivity of the collaborative activity. Finally, this is the first time such type of analysis is attempted on Greek data.

  3. Community Forestry and Forest Conservation

    DEFF Research Database (Denmark)

    Milhøj, Anders; Casse, Thorkil

    2011-01-01

    This paper is a meta-study of local forest management experiences in developing countries drawn from a review of 56 case-studies presented in 52 papers. Many case-studies report positive links between community forestry and forest conservation. In international organizations and NGOs there is a g......This paper is a meta-study of local forest management experiences in developing countries drawn from a review of 56 case-studies presented in 52 papers. Many case-studies report positive links between community forestry and forest conservation. In international organizations and NGOs...

  4. Community College Program Planning: A Method to Measure and Meet Community Need

    Science.gov (United States)

    Perez-Vergara, Kelly; Lathrop, Rachel; Orlowski, Martin

    2018-01-01

    Offering academic programs that meet community need has long been a core mission of community colleges. However, determining which job skills and credentials are needed for employment in the community is challenging. In order to facilitate a holistic and community-based perspective, our 2-year community college developed a structured curricular…

  5. Community-Based Programming: An Opportunity and Imperative for the Community College.

    Science.gov (United States)

    Boone, Edgar J.

    1992-01-01

    Defines community-based programing as a cooperative process in which the community college serves as leader and catalyst in effecting collaboration among community members, leaders, and groups. Recommends 15 tasks for community college leaders involved in community-based programing, including environmental scanning and coalition building. (DMM)

  6. Is a community still a community? Reviewing definitions of key terms in community ecology.

    Science.gov (United States)

    Stroud, James T; Bush, Michael R; Ladd, Mark C; Nowicki, Robert J; Shantz, Andrew A; Sweatman, Jennifer

    2015-11-01

    Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth et al. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; "community," "assemblage," "guild," and "ensemble". We revisit Fauth et al.'s conclusion and discuss how the use of these terms has changed over time since their review. An updated analysis of term definition from a selection of popular ecological textbooks suggests that definitions have drifted away from those encountered pre-1996, and slightly disagreed with results from a survey of 100 ecology professionals (comprising of academic professors, nonacademic PhDs, graduate and undergraduate biology students). Results suggest that confusion about these terms is still widespread in ecology. We conclude with clear suggestions for definitions of each term to be adopted hereafter to provide greater cohesion among research groups.

  7. California Community Colleges Parking Survey.

    Science.gov (United States)

    McIntyre, Chuck

    In 1990, a representative sample of 25 California community colleges was contacted by telephone to determine their parking policies and practices. The colleges were sampled on the basis of location and size. Study findings included the following: (1) 17 of the colleges reported that they had insufficient numbers of on-campus parking spaces; (2)…

  8. Recruiting Parents and the Community.

    Science.gov (United States)

    Clemens-Brower, Teresa Jo

    1997-01-01

    An Oregon elementary teacher attributes her best teaching year ever to parents' and community members' voluntary participation. They got involved in four ways--communicating through voice mail, sharing expertise in the classroom, helping gather lesson materials, and participating in monthly learning celebrations. These activities supplemented…

  9. Critical Community Building: Beyond Belonging

    Science.gov (United States)

    Bettez, Silvia Cristina

    2011-01-01

    In this paper, the author talks about community building and the power of active listening. Active listening is a particular kind of listening that requires conscious effort; it is a type of listening that some rarely practice and sometimes is virtually absent from classroom interactions. Thus active listening itself may be deceptively simple…

  10. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    the_monk

    rural Nigerian communities, out-of-pocket more than a stated percentage ... experience for final year medical students of A total of six hundred and eighty six (686) .... health centre were lack of money (55.2%), household income was not ...

  11. The University and the Community.

    Science.gov (United States)

    Campbell, Duncan

    This paper presented views on the role of the university, and particularly the University of Alberta, in the community in the 1970s. Such indicators as population growth, income growth, rising level of education, rising levels of taxation, the rapidity of technological advance, shifts in social pattern, all pointed to a rapidly growing demand on…

  12. Building consensus in the community

    International Nuclear Information System (INIS)

    Bishop, J.

    1994-01-01

    The importance for the development of UK renewable energy projects of building consensus in the community is discussed. After outlining the benefits of such an approach, some of the likely concerns and questions from a developer's viewpoint are explored. The key principles of good practice are considered and an example from a wind project examined. (UK)

  13. Intentionality, consciousness, and creating community.

    Science.gov (United States)

    Malinski, Violet M

    2009-01-01

    Intentionality is briefly explored from the perspective of seminal written works on therapeutic touch and recorded conversations with Martha E. Rogers. This overview hints at possible interrelationships among intentionality, consciousness, and creating community, along with conceptual ambiguities, which are explored in detail by Zahourek and Larkin in this column.

  14. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    ajiboro

    2Department of Community Medicine & Primary Care, Faculty of Clinical Sciences, ... It may result from road traffic accident, near saving basic principles in emergency care that even drowning, electric ... (4.3%) at place of work, 8 (11.4%) at.

  15. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    the_monk

    Journal of Community Medicine and Primary Health Care. 26 (1) 12-20 .... large proportions of the population work in the poor people use health care services far less than. 19 ... hypertension, cancers and road traffic accidents) below 1 dollar ...

  16. Cambridge community Optometry Glaucoma Scheme.

    Science.gov (United States)

    Keenan, Jonathan; Shahid, Humma; Bourne, Rupert R; White, Andrew J; Martin, Keith R

    2015-04-01

    With a higher life expectancy, there is an increased demand for hospital glaucoma services in the United Kingdom. The Cambridge community Optometry Glaucoma Scheme (COGS) was initiated in 2010, where new referrals for suspected glaucoma are evaluated by community optometrists with a special interest in glaucoma, with virtual electronic review and validation by a consultant ophthalmologist with special interest in glaucoma. 1733 patients were evaluated by this scheme between 2010 and 2013. Clinical assessment is performed by the optometrist at a remote site. Goldmann applanation tonometry, pachymetry, monoscopic colour optic disc photographs and automated Humphrey visual field testing are performed. A clinical decision is made as to whether a patient has glaucoma or is a suspect, and referred on or discharged as a false positive referral. The clinical findings, optic disc photographs and visual field test results are transmitted electronically for virtual review by a consultant ophthalmologist. The number of false positive referrals from initial referral into the scheme. Of the patients, 46.6% were discharged at assessment and a further 5.7% were discharged following virtual review. Of the patients initially discharged, 2.8% were recalled following virtual review. Following assessment at the hospital, a further 10.5% were discharged after a single visit. The COGS community-based glaucoma screening programme is a safe and effective way of evaluating glaucoma referrals in the community and reducing false-positive referrals for glaucoma into the hospital system. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

  17. Community relations 2.0.

    Science.gov (United States)

    Kane, Gerald C; Fichman, Robert G; Gallaugher, John; Glaser, John

    2009-11-01

    Before the Internet, organizations had far more time to monitor and respond to community activity, but that luxury is long gone, leaving them in dire need of a coherent outreach strategy, fresh skills, and adaptive tactics. Drawing on the authors' study of more than two dozen firms, this article describes the changes wrought by social media in particular and shows managers how to take advantage of them--lessons that Kaiser Permanente, Domino's, and others learned the hard way. Social media platforms enhance the power of communities by promoting deep relationships, facilitating rapid organization, improving the creation and synthesis of knowledge, and enabling robust filtering of information. The authors cite many examples from the health care industry, where social media participation is vigorous and influential. For instance, members of Sermo, an online network exclusively for doctors, used the site to call attention to and organize against insurers' proposed reimbursement cuts. And on PatientsLikeMe, where people share details about their chronic diseases and the treatments they've pursued, charts and progress curves help members visualize their own complex histories and allow comparisons and feedback among peers. As you modernize your company's approach to community outreach, you'll need to assemble a social media team equipped to identify new opportunities for engagement and prevent brand damage. In the most successful firms the authors studied, community management was a dedicated function, combining marketing, public relations, and information technology skills.

  18. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    the_monk

    VPDs, this represents 17% of global total. 1 ... Knowledge, Attitude and Practice of Childhood Immunization ... Department of Community Health & Primary Care, College of Medicine, University of Lagos, Idi-Araba, P.M.B. 12003, ... include access to services, parental (maternal) ... Calmette Guerin (BCG) vaccine Oral Polio.

  19. Changing closed agricultural policy communities

    NARCIS (Netherlands)

    Termeer, C.J.A.M.; Werkman, R.A.

    2011-01-01

    Agricultural policy networks have served as classic examples of closed policy communities facing pressure to open up. However, attempts to change them are slowly moving forward. The dialogues on Common Agricultural Policy reforms in which the Dutch Ministry of Agriculture is engaged with a range of

  20. Community-based gang desistance

    DEFF Research Database (Denmark)

    Højgaard Dichmann, Kirstine; Jensen, Tobias Bo; Mørck, Line Lerche

    2018-01-01

    of belonging to the communities in Homeboy Industries also facilitates self-reflection and identity transformation. Homeboy Industries is furthermore an important life changing resource because it offers former gang members a legal source of income. This provides them with a new and secure base, a way...