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Sample records for epilithic periphyton communities

  1. Changes in epilithic communities due to individual and combined treatments of zinc and snail grazing in stream mesocosms

    Energy Technology Data Exchange (ETDEWEB)

    Genter, R.B.; Colwell, F.S.; Pratt, J.R.; Cherry, D.S.; Cairns, J. Jr.

    1988-06-01

    Effects of 0.5 mg/liter zinc (Zn) and snail grazing (400 snails/m2) on density of dominant algal and protozoan taxa, epilithic glucose respiration, and ash-free dry weight (AFDW) were examined using established (12-day colonization) periphyton communities in flow-through stream mesocosms with four treatments (Zn, snails, Zn and snails, control) for 30 days. Grazing and Zn similarly reduced the abundance of 5 of 10 dominant algal taxa and AFDW during the first 10 days of treatment. Abundance of these taxa and AFDW in grazed (ambient Zn) treatments approached control levels after 10 days as the effect due to snails decreased. Decreasing temperatures may have reduced snail activity. Snails, Zn, and the combination of these treatments contributed to higher rates of glucose respiration per unit AFDW. Protozoan species abundance was reduced to less than half by Zn but was unaffected by snails. Although Zn and snails individually altered structural and functional aspects of this microbial community, the effects when both treatments were combined could not always be inferred from the individual effects. Testing individual and combined variables that affect periphyton with a corresponding assessment of population dynamics, biomass, and community functional attributes will enhance understanding of the overall effects of pollutants on periphyton communities.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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 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......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...

  7. Periphyton: ecology, exploitation and management

    NARCIS (Netherlands)

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

    2005-01-01

    Periphyton, as described in this book, refers to the entire complex of attached aquatic biota on submerged substrates, including associated non-attached organisms and detritus. Thus the periphyton community comprises bacteria, fungi, protozoa, algae, zooplankton and other invertebrates. Periphyton

  8. Metagenomic sequencing of marine periphyton: taxonomic and functional insights into biofilm communities.

    Science.gov (United States)

    Sanli, Kemal; Bengtsson-Palme, Johan; Nilsson, R Henrik; Kristiansson, Erik; Alm Rosenblad, Magnus; Blanck, Hans; Eriksson, Karl M

    2015-01-01

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Effect of snails (Elimia clavaeformis) on phosphorus cycling in stream periphyton and leaf detritus communities

    Energy Technology Data Exchange (ETDEWEB)

    Jay, Elizabeth A. [North Carolina Univ., Chapel Hill, NC (United States)

    1993-01-01

    In this study, the author examined the effect of grazing on phosphorus cycling in stream periphyton and leaf detritus communities using the snail Elimia clavaeformis. Phosphorus cycling fluxes and turnover rates were measured in a laboratory and in a natural stream, respectively, using radioactive tracer techniques.

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

    Directory of Open Access Journals (Sweden)

    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. 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.

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Spatiotemporal patterns in community structure of macroinvertebrates inhabiting calcareous periphyton mats

    Science.gov (United States)

    Liston, S.E.; Trexler, J.C.

    2005-01-01

    Calcareous floating periphyton mats in the southern Everglades provide habitat for a diverse macroinvertebrate community that has not been well characterized. Our study described this community in an oligotrophic marsh, compared it with the macroinvertebrate community associated with adjacent epiphytic algae attached to macrophytes in the water column, and detected spatial patterns in density and community structure. The floating periphyton mat (floating mat) and epiphytic algae in the water column (submerged epiphyton) were sampled at 4 sites (???1 km apart) in northern Shark River Slough, Everglades National Park (ENP), in the early (July) and late (November) wet season. Two perpendicular 90-m transects were established at each site and ???100 samples were taken in a nested design. Sites were located in wet-prairie spikerush-dominated sloughs with similar water depths and emergent macrophyte communities. Floating mats were sampled by taking cores (6-cm diameter) that were sorted under magnification to enumerate infauna retained on a 250-??m-mesh sieve and with a maximum dimension >1 mm. Our results showed that floating mats provide habitat for a macroinvertebrate community with higher densities (no. animals/g ash-free dry mass) of Hyalella azteca, Dasyhelea spp., and Cladocera, and lower densities of Chironomidae and Planorbella spp. than communities associated with submerged epiphyton. Densities of the most common taxa increased 3x to 15x from early to late wet season, and community differences between the 2 habitat types became more pronounced. Floating-mat coverage and estimated floating-mat biomass increased 20 to 30%, and 30 to 110%, respectively, at most sites in the late wet season. Some intersite variation was observed in individual taxa, but no consistent spatial pattern in any taxon was detected at any scale (from 0.2 m to 3 km). Floating mats and their resident macroinvertebrate communities are important components in the Everglades food web. This

  17. Seasonal patterns in stream periphyton fatty acids and community benthic algal composition in six high quality headwater streams

    Science.gov (United States)

    Honeyfield, Dale C.; Maloney, Kelly O.

    2015-01-01

    Fatty acids are integral components of periphyton and differ among algal taxa. We examined seasonal patterns in periphyton fatty acids in six minimally disturbed headwater streams in Pennsylvania’s Appalachian Mountains, USA. Environmental data and periphyton were collected across four seasons for fatty acid and algal taxa content. Non-metric multidimensional scaling ordination suggested significant seasonal differences in fatty acids; an ordination on algal composition revealed similar seasonal patterns, but with slightly weaker separation of summer and fall. Summer and fall fatty acid profiles were driven by temperature, overstory cover, and conductivity and winter profiles by measures of stream size. Ordination on algal composition suggested that summer and fall communities were driven by overstory and temperature, whereas winter communities were driven by velocity. The physiologically important fatty acid 18:3ω6 was highest in summer and fall. Winter samples had the highest 20:3ω3. Six saturated fatty acids differed among the seasons. Periphyton fatty acids profiles appeared to reflect benthic algal species composition. This suggests that periphyton fatty acid composition can be useful in characterizing basal food resources and stream water quality.

  18. 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.

  19. Microhabitat selection in the simple oribatid community dwelling in epilithic moss cover (Acari: Oribatida)

    Science.gov (United States)

    Smrž, Jaroslav

    2006-11-01

    The moss cover of a roof was studied as the model of a simple habitat divided into microhabitats by the members of a community of saprophagous mites. This community consisted of two species of oribatid mites: Scutovertex minutus and Trichoribates trimaculatus. They were extracted from moss onto moist paper, and subsequently, their mobility, responses to moisture fluctuation, and food selection were tested in laboratory experiments. For the nutritional biology, the microanatomy of their alimentary tract was examined according to the system of histological characteristics formulated in the laboratory of the author (type of food, digestive activity of gut walls, etc.). The paraplast sections of the mites were stained by Masson triple stain for these purposes. Moreover, the enzymological tests (chitinase and cellulase activities) were performed to detail the digestive processes. Such an approach was applied to field-sampled specimens as well as to those in the laboratory experiments. These above-mentioned data were discussed with respect to microhabitat selection, vertical and horizontal distribution, and dispersal ability of these two oribatid mites sharing this habitat. These two species differ in several characteristics from each other and these differences resulted in their different microhabitat choices and role in the habitat as a whole.

  20. 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

  1. Phospholipid fatty acid biomarkers in a freshwater periphyton community exposed to uranium: discovery by non-linear statistical learning

    Energy Technology Data Exchange (ETDEWEB)

    Webb-Robertson, Bobbie-Jo M.; Bunn, Amoret L.; Bailey, Vanessa L.

    2011-01-01

    Phospholipid fatty acids (PLFA) have been widely used to characterize environmental microbial communities, generating community profiles that can distinguish phylogenetic or functional groups within the community. The poor specificity of organism groups with fatty acid biomarkers in the classic PLFA-microorganism associations is a confounding factor in many of the statistical classification/clustering approaches traditionally used to interpret PLFA profiles. In this paper we demonstrate that non-linear statistical learning methods, such as a support vector machine (SVM), can more accurately find patterns related to uranyl nitrate exposure in a freshwater periphyton community than linear methods, such as partial least squares discriminant analysis. In addition, probabilistic models of exposure can be derived from the identified lipid biomarkers to demonstrate the potential model-based approach that could be used in remediation. The SVM probability model separates dose groups at accuracies of ~87.0%, ~71.4%, ~87.5%, and 100% for the four groups; Control (non-amended system), low-dose (amended at 10 µg U L-1), medium dose (amended at 100 µg U L-1), and high dose (500 µg U L-1). The SVM model achieved an overall cross-validated classification accuracy of ~87% in contrast to ~59% for the best linear classifier.

  2. 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 * bacterial cultivation * carbonatogenesis * vaterite Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.076, year: 2016

  3. Ecology and primary productivity of the eulittoral epilithon community: Lake Tahoe, California-Nevada

    International Nuclear Information System (INIS)

    Aloi, J.E.

    1986-01-01

    This dissertation is an investigation into the factors affecting the community dynamics of an epilithic diatom community in Lake Tahoe. Although Lake Tahoe is characterized by extremely low phytoplankton primary productivity, the productivity of the eulittoral (0-2 m) periphyton community is much higher than would be expected in this extremely oligotrophic lake. The eulittoral periphyton community is structured by as stalked diatom, Gomphoneis herculeana, and rosettes of Synedra ulna, with small diatoms living within this matrix. The seasonal cycle of the eulittoral epilithon was monitored through three growing seasons. Biomass was measured once or twice per month at 12-17 sites. Eulittoral primary productivity was also measured monthly at one site, using in situ C 14 methodology. Field measurements were combined with laboratory experiments to determine the physical and chemical parameters responsible for both the seasonal periodicity and the site-to-site differences in epilithon biomass and primary productivity

  4. 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.

  5. 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.

  6. Distribution patterns of epilithic diatoms along climatic, spatial and physicochemical variables in the Baltic Sea

    OpenAIRE

    Virta, Leena; Soininen, Janne

    2017-01-01

    Abstract The species richness and community composition of the diatom communities were studied in the Baltic Sea, Northern Europe, to enhance knowledge about the diversity of these organisms in a brackish water ecosystem. Many organisms in the Baltic Sea have been studied extensively, but studies investigating littoral diatoms are scarce. The goal of this study was to examine the importance of climatic, spatial and water physicochemical variables as drivers of epilithic diato...

  7. 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

  8. 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

  9. 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

  10. Phosphorus Availability Alters the Effects of Silver Nanoparticles on Periphyton Growth and Stoichiometry.

    Directory of Open Access Journals (Sweden)

    Beth C Norman

    Full Text Available Exposure to silver nanoparticles (AgNPs may alter the structure and function of freshwater ecosystems. However, there remains a paucity of studies investigating the effects of AgNP exposure on freshwater communities in the natural environment where interactions with the ambient environment may modify AgNP toxicity. We used nutrient diffusing substrates to determine the interactive effects of AgNP exposure and phosphorus (P enrichment on natural assemblages of periphyton in three Canadian Shield lakes. The lakes were all phosphorus poor and spanned a gradient of dissolved organic carbon availability. Ag slowly accumulated in the exposed periphyton, which decreased periphyton carbon and chlorophyll a content and increased periphyton C:P and N:P in the carbon rich lakes. We found significant interactions between AgNP and P treatments on periphyton carbon, autotroph standing crop and periphyton stoichiometry in the carbon poor lake such that P enhanced the negative effects of AgNPs on chlorophyll a and lessened the impact of AgNP exposure on periphyton stoichiometry. Our results contrast with those of other studies demonstrating that P addition decreases metal toxicity for phytoplankton, suggesting that benthic and pelagic primary producers may react differently to AgNP exposure and highlighting the importance of in situ assays when assessing potential effects of AgNPs in fresh waters.

  11. Phosphorus Availability Alters the Effects of Silver Nanoparticles on Periphyton Growth and Stoichiometry.

    Science.gov (United States)

    Norman, Beth C; Xenopoulos, Marguerite A; Braun, Daniel; Frost, Paul C

    2015-01-01

    Exposure to silver nanoparticles (AgNPs) may alter the structure and function of freshwater ecosystems. However, there remains a paucity of studies investigating the effects of AgNP exposure on freshwater communities in the natural environment where interactions with the ambient environment may modify AgNP toxicity. We used nutrient diffusing substrates to determine the interactive effects of AgNP exposure and phosphorus (P) enrichment on natural assemblages of periphyton in three Canadian Shield lakes. The lakes were all phosphorus poor and spanned a gradient of dissolved organic carbon availability. Ag slowly accumulated in the exposed periphyton, which decreased periphyton carbon and chlorophyll a content and increased periphyton C:P and N:P in the carbon rich lakes. We found significant interactions between AgNP and P treatments on periphyton carbon, autotroph standing crop and periphyton stoichiometry in the carbon poor lake such that P enhanced the negative effects of AgNPs on chlorophyll a and lessened the impact of AgNP exposure on periphyton stoichiometry. Our results contrast with those of other studies demonstrating that P addition decreases metal toxicity for phytoplankton, suggesting that benthic and pelagic primary producers may react differently to AgNP exposure and highlighting the importance of in situ assays when assessing potential effects of AgNPs in fresh waters.

  12. Integrating understanding of hydrology, geomorphology and ecology to better predict periphyton abundance in New Zealand rivers

    Science.gov (United States)

    Hoyle, Jo; Kilroy, Cathy; Hicks, Murray

    2015-04-01

    Periphyton (the algae dominated community that grows on the bed of rivers) provide a rich food source for the upper trophic levels of stream ecosystems and can also provide an important ecological service by removing dissolved nutrients and contaminants from the flow. However, in excess, periphyton can have negative effects on habitat quality, water chemistry and biodiversity, and can reduce recreation and aesthetic values. The abundance of periphyton in rivers is influenced by a number of factors, but the two key factors that can be directly influenced by human activities are flow regime and nutrient concentrations. River managers in New Zealand are required to set objectives for periphyton abundance that meet or exceed national bottom lines, and they then need to set limits on freshwater quality and quantity in their region to ensure these objectives are met. Consequently, the ability to predict periphyton abundance under different conditions is crucial for management of rivers to protect ecological and other values. Establishing quantitative relationships between periphyton abundance, hydrologic regimes and nutrient concentrations has proven to be difficult but remains an urgent priority in New Zealand. A common index for predicting periphyton abundance has been the frequency of floods greater than 3 times the median flow (FRE3), and this has been successful on a regional average but can be quite unreliable on a site-specific basis. This stems largely from our limited ability to transform flow data into ecologically meaningful physical processes that directly affect periphyton removal (e.g., drag, abrasion, bed movement). The research we will present examines whether geomorphic variables, such as frequency of bed movement, are useful co-predictors in periphyton abundance-flow-nutrient relationships. We collected data on channel topography and bed material size for 20 reaches in the Manawatu-Wanganui Region which have at least 5 years of flow, nutrient

  13. Epilithic algae distribution along a chemical gradient in a naturally acidic river, Río Agrio (Patagonia, Argentina).

    Science.gov (United States)

    Baffico, Gustavo D

    2010-04-01

    The epilithic algae distribution along a pH gradient and the relationship between the chemical gradient and biomass development were studied in Río Agrio, a naturally acidic river located in Patagonia (Argentina). The epilithic community was monitored during the summer of three consecutive years in sites located above and below the entrance of tributaries. The epilithic community showed differences between sites based on the chemical composition of the water and the precipitates that appear on the streambed of the river. The lowest biomass, diversity, and number of species were found at the most extreme part of the river in terms of pH (ca. 2) and element concentrations. Euglena mutabilis was the dominant species in this section of the river. As pH increased (ca. 3), the community changed to be dominated by filamentous green algae (Ulothrix spp., Mougeotia sp., Klebsormidium sp.) showing luxuriant growths in terms of biomass. With the inflow of a neutral tributary, the pH of Río Agrio increased above 3, and the precipitates of orange-red iron hydroxides appeared. The algal community was not affected by these precipitates or the low P concentrations, along the next 30 km of river downstream from this site. The apparent physical stress that the precipitates impose on algae is in fact a dynamic reservoir of P because diel cycle of Fe could be promoting precipitation and redissolution processes that binds and releases P from these precipitates. Where the pH increased above 6, precipitates of aluminum hydroxides appeared. At this site, the epilithic biomass and density decreased, some algae species changed, but the diversity and the number of species in general remained consistent with the upstream values. The physical stress of the Al precipitates on the algae is added to the chemical stress that represents the sequestering of P in these precipitates that are not redissolved, resulting P a limiting nutrient for algae growth.

  14. 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.

  15. Periphyton biomass on artificial substrates during the summer and winter

    Directory of Open Access Journals (Sweden)

    Altevir Signor

    2015-01-01

    Full Text Available This study evaluated the periphyton production on artificial substrates considering it as a source of low cost live food for fish. Blades of artificial substrates such as wood, black plastic, acrylic, fiberglass, ceramics and glass (all with 144cm2 blades, 24 for each substrate were submerged 20.0cm below the water column for 35 days in the winter and 42 days in the summer. The blades were randomly installed in 200m3 pond and evaluated for the biomass production at different phases during the summer and winter. Four blades of each substrate were collected weekly, and the periphytic community was carefully scraped with a spatula and fixed in 4% formaldehyde. The periphytic biomass productivity was evaluated by artificial substrate area and per day. The results evidenced the characteristic periodicity in periphyton biomass production and a significant variability in the collect period and season in the different artificial substrates used. Ceramic and wood showed the best results in the summer while wood showed the best results in the winter. The priphyton biomass productions differ among periods, substrates and seasons. Wood and ceramics could be indicated for periphyton biomass production in either winter or summer.

  16. 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

    Quantifying periphyton (attached algal) contributions to autotrophic production in lakes is confounded by properties of substratum that affect community biomass (as chlorophyll content) and productivity. We compared chlorophyll content and productivity of natural algal communities (phytoplankton,...... of the littoral zones in nutrient and energy cycles in lakes....

  17. 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

  18. Nodularin from benthic freshwater periphyton and implications for trophic transfer.

    Science.gov (United States)

    Foss, Amanda J; Butt, Jeffery; Fuller, Sarah; Cieslik, Kamil; Aubel, Mark T; Wertz, Tim

    2017-12-15

    In 2013 and 2015, the Pennsylvania Department of Environmental Protection conducted a survey of lotic habitats within the Susquehanna, Delaware, and Ohio River basins in Pennsylvania, USA, to screen for microcystins/nodularins (MCs/NODs) in algae communities and smallmouth bass (Micropterus dolomieu). Periphyton (68 from 41 sites), juvenile whole fish (153 from 19 sites) and adult fish liver (115 from 16 sites) samples were collected and screened using an Adda enzyme-linked immunosorbent assay (ELISA). Samples that were positive for MCs/NODs were further analyzed using LC-MS/MS, including 14 variants of microcystin and NOD-R and the MMPB technique. The ELISA was positive for 47% of the periphyton collections, with NOD-R confirmed (0.7-82.2 ng g -1 d.w.) in 20 samples. NOD-R was confirmed in 10 of 15 positive juvenile whole fish samples (0.8-16.7 ng g -1 w.w.) and in 2 of 8 liver samples (1.7 & 2.8 ng g -1 w.w.). The MMPB method resulted in total MCs/NODs measured in periphyton (2.2-1269 ng g -1 d.w.), juvenile whole fish (5.0-210 ng g -1 d.w.) and adult livers (8.5-29.5 ng g -1 d.w.). This work illustrates that NOD-R is present in freshwater benthic algae in the USA, which has broader implications for monitoring and trophic transfer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. 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 <300m to the sewage outfall discharge allowed the success of this classical monitoring method in a temperate marine-coastal ecosystem with certain gradient of pollution. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. 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.

  1. Adaptation of an epilithic ecosystem to harsh high altitude environment

    Science.gov (United States)

    de La Torre Noetzel, R.; Horneck, G.; García Sancho, L.; Scherer, K.; Facius, R.; Urlings, T.; Rettberg, P.; Reina, M.; Pintado, A.

    2003-04-01

    Epilithic ecosystems in high mountains are exposed to an extreme microclimate characterized by intense solar UV radiation, high temperature fluctuations and high aridity. Using the epilithic ecosystem Rhizocarpon geographicum, the most abundant lichen at the Plataforma de Gredos (Sierra de Gredos, Central Spain, 1.895 m a.s.l.) as model system, we have investigated whether the cortex protects the photobiont against impacts by this extreme environment. The UV radiation climate was measured optoelectronically as well by use of the biological dosimeter DLR-Biofilm, and the microclimate (temperature, relative humidity, PAR) by a microclimatic station (Squirrel, U.K.). The photosynthetic activity of the lichens was periodically determined by use of a photosynthesis yield analyser MINI PAM. Using lichen samples with- and without cortex during different periods of a growing season, showed a substantial protection by the cortex against environmental stress conditions, especially at summer solstice. Solar UV radiation and desiccation exerted the most damaging effects in lichens without cortex. Because of the high resistance of the intact lichen against the harsh high altitude climate, R. geographicum has been selected as test system for survival studies in space to be performed during the upcoming BIOPAN mission of ESA.

  2. 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

    Quantifying periphyton (attached algal) contributions to autotrophic production in lakes is confounded by properties of substratum that affect community biomass (as chlorophyll content) and productivity. We compared chlorophyll content and productivity of natural algal communities (phytoplankton......, epipelon, epilithon, epixylon, and epiphyton) experiencing high (>10%) incident radiation in lakes in the US, Greenland, and Quebec, Canada. Chlorophyll content and productivity differed significantly among regions, but they also differed consistently among communities independent of region. Chlorophyll...... 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...

  3. 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.

  4. 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.

  5. 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%) ...

  6. The role of periphyton in mediating the effects of pollution in a stream ecosystem.

    Science.gov (United States)

    Hill, Walter R; Ryon, Michael G; Smith, John G; Adams, S Marshall; Boston, Harry L; Stewart, Arthur J

    2010-03-01

    The effects of pollutants on primary producers ramify through ecosystems because primary producers provide food and structure for higher trophic levels and they mediate the biogeochemical cycling of nutrients and contaminants. Periphyton (attached algae) were studied as part of a long-term biological monitoring program designed to guide remediation efforts by the Department of Energy's Y-12 National Security Complex on East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee. High concentrations of nutrients entering EFPC were responsible for elevated periphyton production and placed the stream in a state of eutrophy. High rates of primary production at upstream locations in EFPC were associated with alterations in both invertebrate and fish communities. Grazers represented >50% of the biomass of invertebrates and fish near the Y-12 Complex but transport of contaminants while simultaneously causing higher concentrations of mercury and PCBs in fish at upstream sites.

  7. 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.

  8. 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.

  9. Structural Interactions among Epilithic Cyanobacteria and Heterotrophic Microorganisms in Roman Hypogea.

    Science.gov (United States)

    Albertano; Urzì

    1999-10-01

    Abstract Phototrophic microbial communities present in the Roman Catacombs were characterized and different species of terrestrial epilithic cyanobacteria were found to occur as dominant organisms. Eucapsis, Leptolyngbya, Scytonema, and Fischerella were the most frequently encountered cyanobacterial taxa, while a few species of green algae and the diatom Diadesmis gallica occurred in minor amounts. Streptomyces strains, a few genera of eubacteria, and to a lesser extent fungi were always present in the same microhabitats and contributed to the deterioration of stone surfaces. The combined use of light and electron microscopy evidenced the structural relationships among rod-shaped or filamentous bacteria and cyanobacterial cells, as well as the presence of polysaccharide capsules and sheaths, and of mineral precipitates on S. julianum filaments. The significance of the intimate association among the microorganisms was discussed in relation to the damage caused by the growth of biological patinas on stone surfaces.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p244.html

  10. Spatial variation of periphyton structural attributes on Eichhornia crassipes (Mart. Solms. in a tropical lotic ecosystem - doi: 10.4025/actascibiolsci.v35i3.17879

    Directory of Open Access Journals (Sweden)

    Valéria Oliveira Fernandes

    2013-08-01

    Full Text Available This study evaluated the influence of physical, chemical and physico-chemical variables of water on the biomass of periphyton community and verified the differences between six sampling sites over the course of São Mateus river: two upstream of the city of São Mateus, Espírito Santo State (E1, E2, two along (E3, E4, and two downstream of the city (E5, E6. The periphyton was collected from roots of Eichhornia crassipes (Mart. Solms. Samplings were undertaken every week in September and October 2010. The periphyton biomass was estimated through chlorophyll ‘a’, biovolume, dry mass, ash-free dry mass, and ash. Higher values of chlorophyll ‘a’ were found at E1, while the total biovolume featured greater values in E4 and E3. Regarding the values of periphyton dry mass, the inorganic fraction was higher at sites along and downstream of the city of São Mateus. The variation of periphyton biomass was influenced by the availability of nutrients (phosphorus and nitrogen and turbidity, as evidenced by the CCA. The results suggest that the input of allochthonous material, especially from human activities (fish farming and discharge of domestic and industrial wastewater, has changed the water quality (as pointed out by the PCA, as well as the communities present.   

  11. Response of stable carbon isotope in epilithic mosses to atmospheric nitrogen deposition

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

    Epilithic mosses are characterized by insulation from substratum N and hence meet their N demand only by deposited N. This study investigated tissue C, total Chl and delta{sup 13}C of epilithic mosses along 2 transects across Guiyang urban (SW China), aiming at testing their responses to N deposition. Tissue C and total Chl decreased from the urban to rural, but delta{sup 13}C{sub moss} became less negative. With measurements of atmospheric CO{sub 2} and delta{sup 13}CO{sub 2}, elevated N deposition was inferred as a primary factor for changes in moss C and isotopic signatures. Correlations between total Chl, tissue C and N signals indicated a nutritional effect on C fixation of epilithic mosses, but the response of delta{sup 13}C{sub moss} to N deposition could not be clearly differentiated from effects of other factors. Collective evidences suggest that C signals of epilithic mosses are useful proxies for N deposition but further works on physiological mechanisms are still needed. - Photosynthetic {sup 13}C discrimination of bryophytes might increase with elevated N deposition.

  12. Gadget for epilithic microalgal sampling (GEMS Dispositivo para amostragem de microalgas epilíticas

    Directory of Open Access Journals (Sweden)

    LGC. Canani

    2010-05-01

    Full Text Available Benthic microalgae sampling in lotic systems is carried out using either artificial or natural substrate. Natural substrate is more suitable for biomass and productivity estimates as well as biodiversity assessment because it contains the communities that are typical of the environment. We present a new gadget for epilithic microalgae sampling (GEMS that allows sampling in situ when it is impossible to remove the substrate from the river bed. The sampler consists of an acrylic box with a 25 cm diameter opening on its base that allows access to the substrate. This gadget can be used in shallow plan bedrock streams and it keeps the sample area isolated as much as possible minimising losses and contamination. It is also easy to construct and handle.As amostragens de microalgas bênticas em sistemas lóticos são realizadas através do uso de substrato natural ou artificial. Substratos naturais são mais adequados para a estimativa de biomassa e produtividade, assim como, para a avaliação de biodiversidade, porque eles contêm as comunidades que são típicas de um determinado ambiente. Nós apresentamos um novo dispositivo para amostragem de microalgas epilíticas (GEMS que permite a amostragem in situ, quando é impossível remover o substrato do leito do rio. O amostrador consiste em uma caixa de acrílico com uma abertura de 25 cm de diâmetro em sua base que permite acesso ao substrato. O amostrador pode ser usado em riachos rasos e de leito rochoso e plano, e mantém a área amostral o mais isolada possível, minimizando perdas e contaminação, além de ser fácil de construir e manusear.

  13. 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.

  14. Periphyton and abiotic factors influencing arsenic speciation in aquatic environments.

    Science.gov (United States)

    Lopez, Adeline R; Silva, Silmara Costa; Webb, Samuel M; Hesterberg, Dean; Buchwalter, David B

    2018-03-01

    Benthic periphytic biofilms are important food sources at the base of aquatic ecosystems. These biofilms also sit at the interface of oxic waters and hypoxic sediments, and can be influenced by or influence trace element speciation. In the present study, we compared arsenic (As) enrichment in periphyton exposed to arsenate (As[V]) or arsenite (As[III]) (20 μg/L, static renewal, 7 d), and we found similar accumulation patterns of total As (101 ± 27 and 88 ± 22 mg kg -1 dry wt, respectively). Periphyton As was 6281- and 6684-fold higher than their aqueous exposures and occurred primarily as As(V). When these biofilms were fed to larval mayflies, similar total As tissue concentrations (13.9 and 14.6 mg kg -1 dry wt, respectively) were observed, revealing significant biodilution (∼ 10% of their dietary concentrations). Finally, we investigated the influence of aeration and periphyton presence on As speciation in solutions and solid phases treated with As(III). Predominantly As(III) solutions were slowly oxidized over a 7-d time period, in the absence of periphyton, and aeration did not strongly affect oxidation rates. However, in the presence of periphyton, solution and solid-phase analyses (by microscale x-ray absorption spectroscopy) showed rapid As(III) oxidation to As(V) and an increasing proportion of organo-As forming over time. Thus periphyton plays several roles in As environmental behavior: 1) decreasing total dissolved As concentrations via abiotic and biotic accumulation, 2) rapidly oxidizing As(III) to As(V), 3) effluxing organo-As forms into solution, and 4) limiting trophic transfer to aquatic grazers. Environ Toxicol Chem 2018;37:903-913. © 2017 SETAC. © 2017 SETAC.

  15. 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

  16. 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.

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

    African Journals Online (AJOL)

    `123456789jkl''''#

    photosynthesis to produce food which the other rung in the aquatic food chain depend directly or indirectly on as food source. Periphyton is capable of nutrient pollution removal down to ..... freshwater, brackish and marine phytoplankton of the Warri/Forcados estuaries of Southern. Nigeria. Nigeria Journal of Botany, 4, 227-.

  18. Relationship between gut content and habitat periphyton and ...

    African Journals Online (AJOL)

    Specimens of Bulinus globosus and B. rohlfsi, intermediate hosts of Schistosoma haematobium were collected from two freshwater habitats in Kano State of Nigeria for a period of 13 months. Their gut contents were analysed and compared with their habitat periphyton and plankton. The results obtained showed that the ...

  19. Optimization of fertilization rate for maximizing periphyton production on artificial substrates and the implications for periphyton-based aquaculture

    NARCIS (Netherlands)

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

    2001-01-01

    The effects of four rates of application of fertilizer, with cow manure (3000 kg ha1), urea (100 (kg ha1) and triple super phosphate (TSP) (100 kg ha1) (treatment F)), treatment F 0.5 (treatment 0.5F), treatment F 1.5 (treatment 1.5F) and treatment F 2 (treatment 2F), on periphyton, plankton and

  20. 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.

  1. 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...

  2. 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

  3. 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.

  4. 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.

  5. Periphyton: an important regulator in optimizing soil phosphorus bioavailability in paddy fields.

    Science.gov (United States)

    Wu, Yonghong; Liu, Junzhuo; Lu, Haiying; Wu, Chenxi; Kerr, Philip

    2016-11-01

    Periphyton is ubiquitous in paddy field, but its importance in influencing the bioavailability of phosphorus (P) in paddy soil has been rarely recognized. A paddy field was simulated in a greenhouse to investigate how periphyton influences P bioavailability in paddy soil. Results showed that periphyton colonizing on paddy soil greatly reduced P content in paddy floodwater but increased P bioavailability of paddy soil. Specifically, all the contents of water-soluble P (WSP), readily desorbable P (RDP), algal-available P (AAP), and NaHCO 3 -extractable P (Olsen-P) in paddy soil increased to an extent compared to the control (without periphyton) after fertilization. In particular, Olsen-P was the most increased P species, up to 216 mg kg -1 after fertilization, accounting for nearly 60 % of total phosphorus (TP) in soil. The paddy periphyton captured P up to 1.4 mg g -1 with Ca-P as the dominant P fraction and can be a potential crop fertilizer. These findings indicated that the presence of periphyton in paddy field benefited in improving P bioavailability for crops. This study provides valuable insights into the roles of periphyton in P bioavailability and migration in a paddy ecosystem and technical support for P regulation.

  6. Removal of parabens and their chlorinated by-products by periphyton: influence of light and temperature.

    Science.gov (United States)

    Song, Chaofeng; Hu, Hongjuan; Ao, Hongyi; Wu, Yonghong; Wu, Chenxi

    2017-02-01

    The extensive use of parabens as preservatives in food and pharmaceuticals and personal care products results in frequent detection of their residuals in aquatic environment. In this work, the adsorption and removal of four parabens (methyl-, ethyl-, propyl-, and butyl-paraben) and two chlorinated methyl-parabens (CMPs) by periphyton were studied. Characteristics of the periphyton were identified to explore the possible relationship between paraben removal and periphyton properties. Results showed that linear adsorption coefficients (K d ) vary from 554.4 to 808.6 L kg -1 for the adsorption parabens and CMPs to autoclaved periphyton. The adsorption strength is positively related to the hydrophobicity of these compounds. Removal of parabens from water by periphyton was efficient with half-life (t 1/2 ) values estimated using first-order kinetic model ranging from 0.49 to 3.29 days, but CMPs were more persistent with t 1/2 ranging from 1.15 to 25.57 days, and t 1/2 increased with the chlorination degree. Higher incubation temperature accelerated the removal of all tested compounds, while a better removal of CMPs was observed in dark condition. Analysis of periphyton properties suggests that bacteria played a more important role in the removal of CMPs, but no specific relationship between periphyton properties and paraben removal ability can be established.

  7. Comparison of usefulness of three types of artificial substrata (glass, wood and plastic) when studying settlement patterns of periphyton in lakes of different trophic status.

    Science.gov (United States)

    Danilov, R A; Ekelund, N G

    2001-07-01

    Usefulness of three types of artificial substrata (glass, wood and plastic) was tested when studying settlement patterns of periphyton in lakes of different trophic status. Strictly eu-, meso- and oligotrophic lakes in central Sweden were chosen as objects of the study. Glass slides, glass tubes, pieces of plastic (PVC) and pieces of wood of similar dimensions were placed for 9 weeks in July-August vertically 3 cm above bottom at a total depth of ca. 30 cm. Substrata were located at well-illuminated places without any other submerged objects (like macrophytes and stones), which could potentially affect colonisation patterns by algae. Periphyton communities, which colonised both the glass tubes and the pieces of wood tested, were specific enough to enable a clear classification of the lakes studied in eu-, meso- and oligotrophic. Glass tubes turned out to be the most favourable substratum when investigating settlement patterns of periphyton in this study. Although also colonised by periphytic species, wood did not support the same diversity and abundance of species as glass did. No algae were detected on the plastics studied. The plastics were covered entirely by a slime layer of bacteria. It is discussed if the nature of plastics could have some inhibitory effects on algal growth or the slime layer itself may have prevented settlement of algal spores.

  8. Assessing water source and channel type as factors affecting benthic macroinvertebrate and periphyton assemblages in the highly urbanized Santa Ana River Basin, California

    Science.gov (United States)

    Burton, C.A.; Brown, L.R.; Belitz, K.

    2005-01-01

    The Santa Ana River basin is the largest stream system in Southern California and includes a densely populated coastal area. Extensive urbanization has altered the geomorphology and hydrology of the streams, adversely affecting aquatic communities. We studied macroinvertebrate and periphyton assemblages in relation to two categorical features of the highly engineered hydrologic system-water source and channel type. Four water sources were identified-natural, urban-impacted groundwater, urban runoff, and treated wastewater. Three channel types were identified-natural, channelized with natural bottom, and concrete-lined. Nineteen sites, covering the range of these two categorical features, were sampled in summer 2000. To minimize the effects of different substrate types among sites, artificial substrates were used for assessing macroinvertebrate and periphyton assemblages. Physical and chemical variables and metrics calculated from macroinvertebrate and periphyton assemblage data were compared among water sources and channel types using analysis of variance and multiple comparison tests. Macroinvertebrate metrics exhibiting significant (P water sources included taxa and Ephemeroptera-Plecoptera-Trichoptera richness, relative richness and abundance of nonchironomid dipterans, orthoclads, oligochaetes, and some functional-feeding groups such as parasites and shredders. Periphyton metrics showing significant differences between water sources included blue-green algae biovolume and relative abundance of nitrogen heterotrophic, eutrophic, motile, and pollution-sensitive diatoms. The relative abundance of trichopterans, tanytarsini chironomids, noninsects, and filter feeders, as well as the relative richness and abundance of diatoms, were significantly different between channel types. Most physical variables were related to channel type, whereas chemical variables and some physical variables (e.g., discharge, velocity, and channel width) were related to water source. These

  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. 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.

  11. 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.

  12. Distribution of Escherichia coli, coliphages and enteric viruses in water, epilithic biofilms and sediments of an urban river in Germany.

    Science.gov (United States)

    Mackowiak, Martin; Leifels, Mats; Hamza, Ibrahim Ahmed; Jurzik, Lars; Wingender, Jost

    2018-06-01

    Fecal contamination of surface water is commonly evaluated by quantification of bacterial or viral indicators such as Escherichia coli and coliphages, or by direct testing for pathogens such as enteric viruses. Retention of fecally derived organisms in biofilms and sediments is less frequently considered. In this study, we assessed the distribution of E. coli, somatic coliphages, and enteric viruses including human adenovirus (HAdV), enterovirus (EV), norovirus genogroup GII (NoV GII) and group A rotavirus (RoV) in an urban river environment in Germany. 24 samples each of water, epilithic biofilms and sediments were examined. E. coli and somatic coliphages were prevalent not only in the flowing water, but also in epilithic biofilms and sediments, where they were accumulated compared to the overlying water. During enhanced rainfall, E. coli and coliphage concentrations increased by approximately 2.5 and 1 log unit, respectively, in the flowing water, whereas concentrations did not change significantly in epilithic biofilms and sediments. The occurrence of human enteric viruses detected by qPCR was higher in water than in biofilms and sediments. 87.5% of all water samples were positive for HAdV. Enteric viruses found less frequently were EV, RoV and NoV GII in 20.8%, 16.7% and 8.3% of the water samples, respectively. In epilithic biofilms and sediments, HAdV was found in 54.2% and 50.0% of the samples, respectively, and EV was found in 4.2% of both biofilm and sediment samples. RoV and NoV GII were not detected in any of the biofilms and sediments. Overall, the prevalence of enteric viruses was in the order of HAdV > EV > RoV ≥ NoV GII. In conclusion, epilithic biofilms and sediments can be reservoirs for fecal indicators and enteric viruses and thus should be taken into consideration when assessing microbial pollution of surface water environments. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Phytoplankton and littoral epilithic diatoms in high mountain lakes of the Adamello-Brenta Regional Park (Trentino, Italy and their relation to trophic status and acidification risk

    Directory of Open Access Journals (Sweden)

    Monica TOLOTTI

    2001-08-01

    Full Text Available A survey of phytoplankton and littoral epilithic diatom communities was carried out on 16 high mountain lakes in the Adamello- Brenta Regional Park (NE Italy as part of a wider research project aimed to the limnological characterisation of the seldom-studied lakes in this Alpine Region. The regional study was supplemented by the analysis of seasonal variations in two representative lakes. The principal goals of this paper are 1 to identify the most important environmental variables regulating patterns in the species composition of both phytoplankton and littoral diatoms, 2 to evaluate whether these algal communities can be used to improve trophic classification and 3 whether they can facilitate monitoring of diffuse human impacts (e.g. airborne pollution on high altitude lakes. The relevance to monitoring is based on the acid sensitivity of all lakes studied, as indicated by the very low average alkalinity values (4-97 μeq l-1 recorded during the investigation period. Chlorophyll-a concentrations and phytoplankton biovolume recorded in the lakes were very low, with maxima in the deep-water layers and in late summer. Phytoplankton communities were dominated by flagellated algae (Chrysophyceae and Dinophyceae. Several coccal green algae were present, while planktonic diatoms were almost completely absent. Littoral diatom communities were dominated by alpine and acidophilous taxa (mainly belonging to the genera Achnanthes and Eunotia. Trophic classification based on phytoplankton and littoral diatoms, respectively, ascribed all lakes to the oligotrophic range. In both algal communities species indicative of acidified conditions were found. Multivariate analyses indicated that both the regional distribution and seasonal variation of phytoplankton are mainly driven by nutrient concentration. Diatoms are predominantly affected by geochemical characteristics including pH and mineralization level.

  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. The impact of extremely low frequency electromagnetic fields on stream periphyton: An eleven-year study

    Science.gov (United States)

    Burton, T.M.; Uzarski, D.G.; Stelzer, R.S.; Eggert, S.L.; Sobczak, W.V.; Mullen, D.M.

    2000-01-01

    Potential effects of extremely low frequency (ELF) electromagnetic fields on periphyton were studied from 1983 to 1993 using a Before, After, Control and Impact design. The study was conducted at two sites on the Ford River, a fourth-order brown water trout stream in Dickinson County, Michigan. The Reference site received 4.9-6.5 times less exposure to ground electric fields and from 300 to 334 times less exposure to magnetic flux from 1989 to 1993 when the antenna was operational at 76 Hz than did the Antenna site. The objective of the study was to determine if ELF electromagnetic fields had caused changes in structure and/or function of algal communities in the Ford River. Significant differences in chlorophyll a standing crop and daily accumulation rate (a surrogate for primary productivity), and organic matter standing crop and daily accumulation rate were observed between the Reference and Antenna site after the antenna became operational. These four related community function variables all increased at the Antenna site with largest and most consistent increases occurring for chlorophyll measures. Compared to pre-operational data, the increase in chlorophyll at the Antenna site also occurred during a period of low amperage testing in 1986-1988, and did not increase further when the antenna became fully operational in 1989, indicating a low threshold for response. There was no significant differences between the Antenna and Reference sites in community structure variables such as diversity, evenness and the relative abundance of dominant diatoms. Thus, 76 Hz ELF electromagnetic radiation apparently did not change the basic makeup of the diatom community but did increase accumulation rates and standing crops of chlorophyll a and organic matter.

  16. Syn-vivo bioerosion of Nautilus by endo- and epilithic foraminiferans (New Caledonia and Vanuatu.

    Directory of Open Access Journals (Sweden)

    Barbara Seuss

    Full Text Available A variety of syn-vivo bioerosion traces produced by foraminiferans is recorded in shells of Nautilus sampled near New Caledonia and Vanuatu. These are two types of attachment scars of epilithic foraminiferans and two forms of previously undescribed microborings, a spiral-shaped and a dendritic one, both most likely being the work of endolithic 'naked' foraminiferans. Scanning electron microscopy of epoxy-resin casts of the latter revealed that these traces occur in clusters of up to many dozen individuals and potentially are substrate-specific. The foraminiferan traces are the sole signs of bioerosion in the studied Nautilus conchs, and neither traces of phototrophic nor other chemotrophic microendoliths were found. While the complete absence of photoautotrophic endoliths would be in good accordance with the life habit of Nautilus, which resides in aphotic deep marine environments and seeks shallower waters in the photic zone for feeding only during night-time, the absence of any microbial bioerosion may also be explained by an effective defence provided by the nautilid periostracum. Following this line of reasoning, the recorded foraminiferan bioerosion traces in turn would identify their trace makers as being specialized in their ability to penetrate the periostracum barrier and to bioerode the shell of modern Nautilus.

  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. Relating river geomorphology to the abundance of periphyton in New Zealand rivers

    Science.gov (United States)

    Hoyle, Jo; Hicks, Murray; Kilroy, Cathy

    2013-04-01

    Aquatic plants (including both periphyton and macrophytes) are a natural component of stream and river systems. However, abundant growth of instream plants can have detrimental impacts on the values of rivers. For example, periphyton in rivers provides basal resources for food webs and provides an important ecological service by removing dissolved nutrients and contaminants from the water column. However, high abundance of periphyton can have negative effects on habitat quality, water chemistry and biodiversity, and can reduce recreation and aesthetic values. The abundance of periphyton in rivers is influenced by a number of factors, but two key factors can be directly influenced by human activities: flow regimes and nutrient concentrations. Establishing quantitative relationships between periphyton abundance and these factors has proven to be difficult but remains an urgent priority due to the need to manage the ecological impacts of water abstraction and eutrophication of rivers worldwide. This need is particularly strong in New Zealand, where there is increasing demand for water for industry, power generation and agriculture. However, we currently have limited ability to predict the effects of changes in the mid-range flow regime on the presence/absence, abundance and composition of aquatic plants. Current water allocation limits are based on simple flow statistics, such as multiples of the median flow, but these are regional averages and can be quite unreliable on a site-specific basis. This stems largely from our limited ability to transform flow data into ecologically meaningful physical processes that directly affect plants (e.g., drag, abrasion, bed movement). The research we will present examines whether geomorphic variables, such as frequency of bed movement, are useful co-predictors in periphyton abundance-flow relationships. We collected topographic survey data and bed sediment data for 20 study reaches in the Manawatu-Wanganui region of New Zealand

  19. ‘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

  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. 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

  2. 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.

  3. PERIPHYTON AND SEDIMENT BIOASSESSMENT AS INDICATORS OF THE EFFECT OF A COASTAL PULP MILL WASTEWATER

    Science.gov (United States)

    A two year study was conducted near Port St. Joe, Florida, in a coastal transportation canal and bay receiving combined municipal and pulp mill wastewater. The objective of the study was to determine the effectiveness of periphyton analysis techniques and sediment toxicity as ind...

  4. The effects of periphyton substrate and fish stocking density on water quality

    NARCIS (Netherlands)

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

    2003-01-01

    The objectives of this study were to determine how periphyton and phytoplankton biomass vary with grazing pressure by tilapia Oreochromis niloticus, to evaluate the growth performance of fish when substrate is introduced and to calculate the efficiency of nitrogen utilization in substrate and

  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. 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 ...

  7. 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....

  8. Responses of Periphyton to Fe2O3Nanoparticles: A Physiological and Ecological Basis for Defending Nanotoxicity.

    Science.gov (United States)

    Tang, Jun; Zhu, Ningyuan; Zhu, Yan; Liu, Junzhuo; Wu, Chenxi; Kerr, Philip; Wu, Yonghong; Lam, Paul K S

    2017-09-19

    The toxic effects of nanoparticles on individual organisms have been widely investigated, while few studies have investigated the effects of nanoparticles on ubiquitous multicommunity microbial aggregates. Here, periphyton as a model of microbial aggregates, was employed to investigate the responses of microbial aggregates exposed continuously to Fe 2 O 3 nanoparticles (5.0 mg L -1 ) for 30 days. The exposure to Fe 2 O 3 nanoparticles results in the chlorophyll (a, b, and c) contents of periphyton increasing and the total antioxidant capacity decreasing. The composition of the periphyton markedly changes in the presence of Fe 2 O 3 nanoparticles and the species diversity significantly increases. The changes in the periphyton composition and diversity were due to allelochemicals, such as 3-methylpentane, released by members of the periphyton which inhibit their competitors. The functions of the periphyton represented by metabolic capability and contaminant (organic matter, nitrogen, phosphorus and copper) removal were able to acclimate to the Fe 2 O 3 nanoparticles exposure via self-regulation of morphology, species composition and diversity. These findings highlight the importance of both physiological and ecological factors in evaluating the long-term responses of microbial aggregates exposed to nanoparticles.

  9. 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.

  10. Epilithic diatom assemblages and their relationships with environmental variables in the Nilüfer Stream Basin, Bursa, Turkey.

    Science.gov (United States)

    Karacaoğlu, Didem; Dalkıran, Nurhayat

    2017-05-01

    Patterns of epilithic diatom species distribution in relation to environmental variables from 12 sampling sites on the main stream and some of its tributaries in the Nilüfer Stream Basin were determined using multivariate statistical techniques. The stream basin has been heavily influenced by anthropogenic effects. The upper part of the basin that is distant from pollution sources mostly has a spring water quality, while the lower part where the stream flows through the urban area and receives domestic and industrial wastewater has a quite low quality. Ordination techniques using both diatom taxa and 21 environmental variables revealed non- to slightly polluted upper basin sites and highly polluted lower basin sites along the stream. The results showed that the stream catchment is polluted gradually from upstream to downstream and that most of the downstream sites have very low water quality especially in summer months. A total of 134 epilithic diatom taxa belonging to 50 genera were recorded for 12 sample sites. Partial CCA results indicated that water temperature (T), discharge (Q), and total phosphorus (TP) were the most important variables affecting the distribution of diatom species. Unpolluted or slightly polluted upper basin sites were dominated by Achnanthidium minutissimum, Cocconeis placentula var. euglypta, Gomphonema olivaceum, and Navicula tripunctata. Highly polluted lower basin sites were characterized by high levels of organic and inorganic matters and low dissolved oxygen (DO) values. Species widespread in the highly polluted lower basin sites such as Nitzschia umbonata, Nitzschia amphibia, Nitzschia capitellata, Nitzschia palea, Nitzschia paleacea, Luticola mutica, and Stephanodiscus niagarae were mostly related to pollution indicator variables such as ammonium nitrogen (NH 4 + -N), sodium (Na + ), total phosphorus (TP), and total organic matter (TOM).

  11. Heavy metal accumulation by periphyton is related to eutrophication in the Hai River Basin, Northern China.

    Directory of Open Access Journals (Sweden)

    Wenzhong Tang

    Full Text Available The Hai River Basin (HRB is one of the most polluted river basins in China. The basin suffers from various types of pollutants including heavy metals and nutrients due to a high population density and rapid economic development in this area. We assessed the relationship between heavy metal accumulation by periphyton playing an important role in fluvial food webs and eutrophication in the HRB. The concentrations of the unicellular diatoms (type A, filamentous algae with diatoms (type B, and filamentous algae (type C varied along the river, with type A dominating upstream, and types B then C increasing in concentration further downstream, and this was consistent with changes in the trophic status of the river. The mean heavy metal concentrations in the type A, B and C organisms were Cr: 18, 18 and 24 mg/kg, respectively, Ni: 9.2, 10 and 12 mg/kg, respectively, Cu: 8.4, 19 and 29 mg/kg, respectively, and Pb: 11, 9.8 and 7.1 mg/kg respectively. The bioconcentration factors showed that the abilities of the organisms to accumulate Cr, Ni and Pb decreased in the order type A, type B, then type C, but their abilities to accumulate Cu increased in that order. The Ni concentration was a good predictor of Cr, Cu and Pb accumulation by all three periphyton types. Our study shows that heavy metal accumulation by periphyton is associated with eutrophication in the rivers in the HRB.

  12. 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.

  13. 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.

  14. Aquatic microbiota diversity in the culture of Nile tilapia (Oreochromis niloticus using bioflocs or periphyton: virulence factors and biofilm formation

    Directory of Open Access Journals (Sweden)

    Jéssica Lucinda Saldanha da Silva

    2016-08-01

    Full Text Available The following research isolated and identified the main bacterial groups present in the culture of juvenile Nile tilapia in the presence of bioflocs and/or periphyton. The strains were also tested for the production of exoenzymes, indicative of potential virulence factors, and ability to form biofilm. The water samples were taken from tilapia cultured in the presence of bioflocs (T1, in the presence of bioflocs and periphyton (T2, from traditional culture (T3 and from culture in the presence of periphyton (T4. In the growth and selection of the bacterial groups, pour plate method was used, along with the following media: Plate Count Agar (PCA - DIFCO, Aero Pseudo Selective Agar (GSP - Himedia and Nutrient Agar (AN - Merck. 46 strains were isolated in the following distribution: T1 (n = 12; T2 (n = 10; T3 (n = 14 and T4 (n = 10. Among the isolates, the most frequent genera were: Pseudomonas spp., Aeromonas spp., Staphylococcus spp., Bacillus spp., Mycobacterium spp., Micrococcus spp., and Corybacterium spp. Bacterial isolates in treatments T1 and T3 tested positive for five virulence profiles each, while those isolated from T2 and T4 for two and three virulence profiles, respectively. Treatments in bioflocs and periphyton (T2 or only periphyton (T4 yielded bacteria of less pathogenic potentials. In relation to the fish growth, T1 and T4 resulted in a higher final weight.

  15. Factors driving epilithic algal colonization in show caves and new insights into combating biofilm development with UV-C treatments.

    Science.gov (United States)

    Borderie, Fabien; Tête, Nicolas; Cailhol, Didier; Alaoui-Sehmer, Laurence; Bousta, Faisl; Rieffel, Dominique; Aleya, Lotfi; Alaoui-Sossé, Badr

    2014-06-15

    The proliferation of epilithic algae that form biofilms in subterranean environments, such as show caves, is a major problem for conservators. In an effort to reduce the use of chemical cleansers when addressing this problem, we proposed investigating the effects of UV-C on combating algal biofilm expansion in a cave located in northeastern France (Moidons Cave). First, the biofilms and cavity were studied in terms of their algal growth-influencing factors to understand the dynamics of colonization in these very harsh environments. Next, colorimetric measurements were used both to diagnose the initial colonization state and monitor the UV-C-treated biofilms for several months after irradiation. The results indicated that passive dispersal vectors of the viable spores and cells were the primary factors involved in the cave's algae repartition. The illumination time during visits appeared to be responsible for greater colonization in some parts of the cave. We also showed that colorimetric measurements could be used for the detection of both thin and thick biofilms, regardless of the type of colonized surface. Finally, our results showed that UV-C treatment led to bleaching of the treated biofilm due to chlorophyll degradation even one year after UV-C treatment. However, a re-colonization phenomenon was colorimetrically and visually detected 16months later, suggesting that the colonization dynamics had not been fully halted. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Association between periphyton and bioflocs systems in intensive culture of juvenile Nile tilapia

    Directory of Open Access Journals (Sweden)

    Davi de Holanda Cavalcante

    2016-05-01

    Full Text Available The present work aimed at determining the effects of the association between the periphyton-based system with the bioflocs-based system in the intensive culture of juvenile Nile tilapia (1.56 ± 0.07 g; 72 fish m-3, on variables of water quality, growth performance and effluent quality after 10 weeks. The experiment was arranged in a 2 x 2 factorial randomized block design with four treatments and five repetitions each. The factors tested were the following: ‘underwater structure’ (absence and presence and ‘adjustment of the C: N ratio of water’ (no and yes. The final fish body weight, specific growth rate and yield were higher (p < 0.05 in the C: N-adjusted tanks. The presence of submerged structures in the tanks had no significant influence on those same variables. It was concluded that the periphyton-based system is not indicated for intensive farming of Nile tilapia, in which there is a high allowance of artificial feed to fish.

  17. C/N ratio control and substrate addition for periphyton development jointly enhance freshwater prawn Macrobrachium rosenbergii production in ponds

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Huque, S.; Salam, M.A.; Azim, M.E.

    2008-01-01

    The present research investigated the effect of carbon/nitrogen ratio (C/N ratio) control in ponds with or without substrate addition for periphyton development on production of giant freshwater prawn. C/N ratios of 10, 15 and 20 were investigated in 40 m¿ 2 ponds stocked with 2 prawn juveniles

  18. 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

  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. Removal of nutrients and pharmaceuticals and personal care products from wastewater using periphyton photobioreactors.

    Science.gov (United States)

    Kang, Du; Zhao, Qichao; Wu, Yonghong; Wu, Chenxi; Xiang, Wu

    2018-01-01

    In this work, periphyton photobioreactors were built and were used for the treatment of synthetic wastewater spiked with PPCPs under different operational conditions. The removal rates of total nitrogen were relatively stable and varied from 39% to 77% overtime in different treatments. However, the removal rates of soluble reactive phosphorus decreased overtime from 42% to 68% on day 2 to 15.8% to 44% on day 22. For the selected PPCPs, only bisphenol A was effectively removed (72%-86.4%), hydrochlorothiazide and ibuprofen were moderately removed (26.2%-48.7%), and carbamazepine and gemfibrozil were poorly removed (6.45%-20.6%). Longer hydraulic retention time enhanced the treatment efficiency but illumination period showed contrasting effects on the removal of the nutrients and the PPCPs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A continuous-flow periphyton bioassay: tests of nutrient limitation in a tundra stream

    International Nuclear Information System (INIS)

    Peterson, B.J.; Hobbie, J.E.; Corliss, T.L.; Kriet, K.

    1983-01-01

    The effect of added nutrients on the periphyton of a tundra stream was tested during July and August. Flow-through systems consisting of a bank of clear plastic tubes containing racks of microscope slides were suspended from floats in the stream. Nutrients were enriched in the experimental tubes by siphoning concentrated nutrient solutions from Mariotte bottles into the upstream end of each tube. Slides from each tube were assayed at 2-6 day intervals for chlorophyll content and photosynthetic 14 CO 2 uptake. Levels of chlorophyll and CO 2 uptake were significantly higher than the controls both in the tubes with 10μg PO 4 -P>liter -1 of stream water and in those with P plus 100 μg NH 4 NO 3 -N.liter. Nitrogen alone gave no stimulation

  2. 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

  3. Arsenic (V) bioconcentration kinetics in freshwater macroinvertebrates and periphyton is influenced by pH.

    Science.gov (United States)

    Lopez, Adeline R; Funk, David H; Buchwalter, David B

    2017-05-01

    Arsenic is an important environmental pollutant whose speciation and mobility in freshwater food webs is complex. Few studies have characterized uptake and efflux rates of arsenic in aquatic benthic invertebrates. Further, we lack a fundamental understanding of how pH influences uptake kinetics in these organisms or how this key environmental variable could alter dietary exposure for primary consumers. Here we used a radiotracer approach to characterize arsenate accumulation dynamics in benthic invertebrates, the influence of pH on uptake in a subset of these organisms, and the influence of pH on uptake of arsenate by periphyton - an important food source at the base of aquatic food webs. Uptake rate constants (K u ) from aqueous exposure were modest, ranging from ∼0.001 L g -1 d -1 in three species of mayfly to 0.06 L g -1 d -1 in Psephenus herricki. Efflux rate constants ranged from ∼0.03 d -1 in Corbicula fluminea to ∼0.3 d -1 in the mayfly Isonychia sp, and were generally high. Arsenate uptake decreased with increasing pH, which may be a function of increased adsorption at lower pHs. A similar but much stronger correlation was observed for periphyton where K u decreased from ∼3.0 L g -1 d -1  at 6.5 pH to ∼0.7 L g -1 d -1  at 8.5 pH, suggesting that site specific pH could significantly alter arsenic exposure, particularly for primary consumers. Together, these findings shed light on the complexity of arsenic bioavailability and help explain observed differences reported in the literature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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.

  5. 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.

  6. 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.

  7. A comparative analysis of ontomorphogenesis of the gametophytes of two epilithic ferns Asplenium adiantum-nigrum and Adiantum capillus-veneris L.

    Directory of Open Access Journals (Sweden)

    Zoya M. Ivaschenko

    2014-04-01

    Full Text Available A comparative study of ontomorphogenesis and polyvariance of two epilithic ferns gametophytes Asplenium adiantum-nigrum and Adiantum capillus-veneris is carried out. The spores of two species significantly differ in their structure. The germination of spores of two species goes on Vittaria-type. The development of prothallium goes on two different types. The investigated ferns also showed significant morphological diversity of gametophytes forms. The differences are found also and in the location of gametangiums on prothallus, and in the rates of sexualization. At the studied species vegetative reproduction by means of proliferation is noted. The following types of ontogenesis are tracked: full and reduced functionally finished ontogenesis with reproduction of diplophase (sporophytes, and also full and reduced functionally not finished ontogenesis. The structural and dynamic polyvariance of gametophytes ontogenesis of two species of ferns is found out.

  8. Production of periphyton to enhance yield in polyculture ponds with carps and small indigenous species

    Directory of Open Access Journals (Sweden)

    Sabita Jha

    2018-02-01

    Full Text Available Although carp polyculture is well established throughout southern Asia, its overall efficiency in providing sufficient nutrients and financial profit remains variable. Site-specific adjustments are needed to improve efficiencies of polyculture under local circumstances. We evaluated variations of carp polyculture systems in two separate trials: one on a research station (on-station, and one in farmers’ ponds (on-farm. The on-station experiment included four treatments: TF (carp + 100% feed, TFS (carp + SIS (small indigenous species +100% feed, TFSP (carp + SIS + 50% feed + bamboo substrate and TSP (carp + SIS+ bamboo substrate with no feed, each done with three replicates. Silver carp (Hypophthalmichthys molitrix, bighead carp (Aristichthys nobilis, grass carp (Ctenopharyngodon idella, common carp (Cyprinus carpio, rohu (Labeo rohita, and mrigal (Cirrhinus mrigala were stocked at a ratio of 4:1:4:3:5:5 and a rate of 15,000 fish/ha. Additionally, 2 SIS, dedhuwa (Esomus danricus and pothi (Puntius sophore, were stocked at 1:1 and a combined density of 50,000 fish/ha. Carps were fed daily at 5% of body weight (BW for 60 days, then 2% BW for 150 days, using a supplemental feed composed of dough (mustard oil cake and rice bran (1:1, or using grass (for grass carp. Total carp yield and FCR were highest in TFSP ponds. Gross margin was also higher in treatments enhanced with periphyton (TFSP and TSP. Overall, TFSP was determined the best on-station result, based on total production of fish and profit. The two treatments with the highest net fish yield, TF and TFSP, were introduced to 37 women farmers in Chitwan and Nawalparasi districts for on-farm trials. After 8 months of culture, total fish weight and gross margin were 24.0% and 51.2% higher, respectively, in TFSP ponds than in TF ponds. Reduced feed application with increased periphyton enhancement dramatically improved profit while maintaining fish yields similar to

  9. FLOATING COMMUNITIES OF ALGAE IN AN ARTIFICIAL POND IN THE PARQUE DO ESTADO, SÃO PAULO, BRAZIL(1).

    Science.gov (United States)

    de Mattos Bicudo, C E; Teixeira Bicudo, R M

    1967-12-01

    A fresluvater floating algal community was repeatedly observed in an artificial pond in the Parque do Estado São Paulo, Brazil. The ontogeny and composition of the community are discussed and are related to oxygen liberation during photosynthesis of the periphyton, or of the pond-bottom algne, which carries up portions of the algae growing there.

  10. 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

  11. Epilithic diatoms in headwater areas of the hydrographical sub-basin of the Andreas Stream, RS, Brazil, and their relation with eutrophication processes

    Directory of Open Access Journals (Sweden)

    Carla Giselda Heinrich

    2014-12-01

    Full Text Available AIM: This research aimed to study the composition of epilithic diatom flora in headwater areas of the sub-basin of the Andreas stream, RS, Brazil, and their relation with eutrophication processes. METHODS: Quarterly excursions (March, June, September, December 2012 and Mach 2013 were performed in ten sampling points selected in the sub-basin, to collect samples for the identification and counting the organisms in the group of diatoms (Class Bacillariophyceae. RESULTS: The results indicated the occurrence of 243 taxa, distributed in 53 genera. Of these, 59 were considered abundant, being distributed in 29 genera. Seven species showed elevated tolerance levels to organic pollution and eutrophication: Adlafia drouetiana (R. M. Patrick Metzeltin & Lange-Bertalot, Amphipleura lindheimeri Grunow; Fallacia monoculata (Hustedt D. G. Mann, Navicula cryptotenella Lange-Bertalot, Navicula symmetrica R. M. Patrick, Nitzschia palea (Kützing W. Smith and Sellaphora auldreekie D. G. Mann & S. M. McDonald in Mann et al. CONCLUSION: Although this research has been conducted in headwater areas, the occurrence of these seven species could be explained by considering the use of these areas for agricultural and livestock purposes, compromising the stability of these aquatic ecosystems, due to the significant contribution of fertilizer and organic matter, a condition that characterizes a process of eutrophication.

  12. 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

  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 stocking density, periphyton substrate and supplemental feed on biological processes affecting water quality in earthen tilapia-prawn polyculture ponds

    NARCIS (Netherlands)

    Sharif Uddin, M.; Milstein, A.; Ekram Azim, M.; Abdul Wahab, M.; Verdegem, M.C.J.; Verreth, J.A.J.

    2008-01-01

    The technical and economic potentials of tilapia, Oreochromis niloticus (L.), and giant river prawn, Macrobrachium rosenbergii (de Man), polyculture in periphyton-based systems are under investigation in an extensive research programme. This article is a combined analysis of data from four

  15. 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

  16. 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.

  17. 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.

  18. COMMUNITY DEVELOPMENT IN FRESHWATER MICROCOSMS

    Energy Technology Data Exchange (ETDEWEB)

    Rees, John T.

    1978-01-01

    Two cylindrical freshwater microcosms with a volume of 700 {ell} were maintained under controlled laboratory conditions for 190 days. The two microcosms were identical with regard to initial chemical composition and biological inocula, with the exceptions that in one microcosm (designated Tank 2) mosquitofish (Gambusia) and herbivorous catfish (Placostomas) were added. Three distinct communities developed in the tanks: (1) a phytoplankton-zooplankton assemblage and (2) two periphyton-zoobenthos communities associated with the sides and bottom of the tank, respectively. Community development and successional patterns were similar in both tanks. Major differences between the tanks involved timing of succession of the zooplankton and zoobenthos, attributable to predation by fish, principally Gambusia. A major drawback for these microcosms as use for experimental analogs such as lakes was a luxuriant periphyton growth which eventually overwhelmed the biomass of the system. The tanks displayed a degree of successional replicability, a large number of species, and a diversity of community development. Microcosms of this size could find use as experimental systems for higher level trophic manipulation and observation of life cycles not amenable to field studies.

  19. 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.

  20. Periphyton biofilms: A novel and natural biological system for the effective removal of sulphonated azo dye methyl orange by synergistic mechanism.

    Science.gov (United States)

    Shabbir, Sadaf; Faheem, Muhammad; Ali, Naeem; Kerr, Philip G; Wu, Yonghong

    2017-01-01

    Due to their large scale use, azo dyes are adversely affecting aquatic fauna and flora as well as humans. The persistent nature of sulphonated azo dyes makes them potential ecotoxic hazards. The aim of the present study was to employ a proficient, locally available biomaterial, viz. periphyton (i.e. epiphyton, epilithon or metaphyton), for removal of the azo dye, methyl orange (MO). Results showed that the periphytic biofilms are capable of completely removing comparatively high concentrations (up to 500 mg L -1 ) of MO from wastewater. The removal of MO occurs by a synergistic mechanism involving bioadsorption and biodegradation processes. The adsorption of MO by periphyton can be described by pseudo-second order kinetics. Elovich and intraparticle diffusion models as well as Langmuir equations fit well to the MO adsorption process. FTIR analysis of MO and its metabolites demonstrated biotransformation into simpler compounds within 72 h. GC-MS/MS analysis showed the conversion of MO into simpler compounds such as phenol, ethyl acetate and acetyl acetate. The results indicated that periphyton is a promising biomaterial for the complete removal of MO from wastewater and that the treatment process has the potential for in situ removal of MO at contaminated sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Does Moss Grow on a Rolling Stone? The Influence of Precipitation Phase on Streamflow Characteristics, Bed Particle Transport and Periphyton Development in 18 Mountain Channels, Central Idaho

    Science.gov (United States)

    Tennant, C.; Crosby, B. T.; Baxter, C.

    2012-12-01

    It has been suggested that linked ecological and geomorphological systems exhibit complex and non-linear response to disturbance. However, quantifying the response of these systems is complicated by identifying the relevant linkages between system components and by variability in time scale adjustments. To help elucidate some of these complexities we characterized the influence of streamflow and bed-substrate mobility on periphyton assemblage development. Study catchments are subdivided into 3 categories based on the fraction of precipitation that fell as rain vs. snow. The categories are rain-dominated (RD), mixed rain-snow (MRS) and snow-dominated (SD). Three water years of streamflow data demonstrate that RD catchments experienced the largest inter-regime and inter-annual variability in streamflow conditions. RD sites were characterized by flashy responses to frequent precipitation events during wet winter and spring months and experienced channel drying during the summer. Runoff in MRS and SD catchments was characterized by much higher magnitude, longer duration flow events in early and mid-summer. Hydrologic results suggest that RD watersheds limit periphyton mass because of drought conditions and that MRS and SD channels control the temporal scale of periphyton development via long duration, high magnitude flood events that transport bed sediments and disrupt primary production. Results from our rock-tracing experiment indicate that assessments of biological disturbance based on hydrologic metrics alone miss important details of the characteristics of physical disturbance within channels. Channels within RD catchments appear to be in disequilibrium because of variability in the frequency and consistency of hydrologic events capable of mobilizing bed particles. Wet winters resulted in frequent and flashy streamflow events that likely caused bedload transport, whereas drier winters caused few streamflow events and subsequently little to no bedload transport

  2. 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…

  3. Cellulomonas phragmiteti sp. nov., a cellulolytic bacterium isolated from reed (Phragmites australis) periphyton in a shallow soda pond.

    Science.gov (United States)

    Rusznyák, Anna; Tóth, Erika M; Schumann, Peter; Spröer, Cathrin; Makk, Judit; Szabó, Gitta; Vladár, Péter; Márialigeti, Károly; Borsodi, Andrea K

    2011-07-01

    An alkalitolerant and moderately halophilic strain, designated KB23(T), characterized by optimal growth at pH 8.0-9.0 and in the presence of 5-7 % (w/v) NaCl, was isolated from a reed (Phragmites australis) periphyton sample originating from an extremely shallow, alkaline soda pond located in Hungary. Cells of strain KB23(T) were Gram-stain-positive, motile straight rods. Strain KB23(T) was facultatively anaerobic, catalase-positive, oxidase-negative and contained peptidoglycan type A4β (L-Orn-D-Asp). MK-9(H4) was the predominant isoprenoid quinone and anteiso-C(15 : 0), C(16 : 0) and anteiso-C(15 : 1) were the major cellular fatty acids. The DNA G+C content of strain KB23(T) was 74.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain belongs to the genus Cellulomonas and that it is related most closely to Cellulomonas flavigena DSM 20109(T) (97.35 % similarity), Cellulomonas terrae DB5(T) (96.81 %), Cellulomonas iranensis O(T) (96.75), Cellulomonas chitinilytica X.bu-b(T) (96.60 %), Cellulomonas persica I(T) (96.53 %), Cellulomonas composti TR7-06(T) (96.45 %), Cellulomonas biazotea DSM 20112(T) (96.34 %) and Cellulomonas fimi DSM 20113(T) (96.20 %). According to these results, together with DNA-DNA hybridization and physiological data, strain KB23(T) is considered to represent a novel species of the genus Cellulomonas, for which the name Cellulomonas phragmiteti sp. nov. is proposed. The type strain is KB23(T) ( = DSM 22512(T)  = NCAIM B002303(T)).

  4. 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

  5. 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

  6. Trophic dynamics in an aquatic community: interactions among primary producers, grazers, and a pathogenic fungus.

    Science.gov (United States)

    Buck, Julia C; Scholz, Katharina I; Rohr, Jason R; Blaustein, Andrew R

    2015-05-01

    Free-living stages of parasites are consumed by a variety of predators, which might have important consequences for predators, parasites, and hosts. For example, zooplankton prey on the infectious stage of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), a pathogen responsible for amphibian population declines and extinctions worldwide. Predation on parasites is predicted to influence community structure and function, and affect disease risk, but relatively few studies have explored its consequences empirically. We investigated interactions among Rana cascadae tadpoles, zooplankton, and Bd in a fully factorial experiment in outdoor mesocosms. We measured growth, development, survival, and infection of amphibians and took weekly measurements of the abundance of zooplankton, phytoplankton (suspended algae), and periphyton (attached algae). We hypothesized that zooplankton might have positive indirect effects on tadpoles by consuming Bd zoospores and by consuming phytoplankton, thus reducing the shading of a major tadpole resource, periphyton. We also hypothesized that zooplankton would have negative effects on tadpoles, mediated by competition for algal resources. Mixed-effects models, repeated-measures ANOVAs, and a structural equation model revealed that zooplankton significantly reduced phytoplankton but had no detectable effects on Bd or periphyton. Hence, the indirect positive effects of zooplankton on tadpoles were negligible when compared to the indirect negative effect mediated by competition for phytoplankton. We conclude that examination of host-pathogen dynamics within a community context may be necessary to elucidate complex community dynamics.

  7. ECOLOGICAL ASPECTS OF BENTHIC COMMUNITIES FROM SOMESUL CALD CATCHMENT AREA

    Directory of Open Access Journals (Sweden)

    Karina Battes

    2001-01-01

    Full Text Available The present paper represents a preliminary study of periphyton and zoobenthos community from the Someşul Cald catchment area. Zoobenthos was sampled seasonally during 2000. Benthic community structure was similar at the five sampling sites. Thus, mayflies and chironomids recorded high numerical percentage abundances and densities. Oligochaetes, water mites and caddisflies were identified to species level. 38 Oligochaeta, 28 water mite and 12 caddis fly species were found in the sampling period. The samplings collected in the year 2001 included 80 algal species belonging to 5 phyla. Diatoms (Bacillariophyta dominated both qualitatively and quantitatively at all sampling sites.

  8. Influence of littoral periphyton on whole-lake metabolism relates to littoral vegetation in humic lakes.

    Science.gov (United States)

    Vesterinen, Jussi; Devlin, Shawn P; Syväranta, Jari; Jones, Roger I

    2017-12-01

    The role of littoral habitats in lake metabolism has been underrated, especially in humic lakes, based on an assumption of low benthic primary production (PP) due to low light penetration into water. This assumption has been challenged by recent recognition of littoral epiphyton dominance of whole-lake PP in a small highly humic lake and of epiphyton as an important basal food source for humic lake biota. However, as these studies have mostly concerned single lakes, there is a need to test their wider generality. We studied the whole-lake PP and community respiration (CR) in eight small humic lakes in southern Finland during July 2015 using 14 C incorporation to measure pelagic PP and the changes in dissolved inorganic carbon in light and dark in situ incubations to measure CR and littoral PP by epiphyton. Changes in O 2 concentration in both pelagic and littoral surface water were measured periodically from each lake and, additionally, continuously with a data logger from one lake during the study period. The results revealed that the littoral dominated whole-lake net primary production (NPP) in five of the eight lakes, which was supported by observed O 2 supersaturation in the littoral surface water in most of the lakes. Calculated pelagic:littoral ratios by area correlated negatively with both littoral NPP and littoral contribution to whole-lake NPP. Moreover, there was a significant positive relationship between littoral proportion of whole-lake NPP and the fraction of lake surface area covered by littoral aquatic vegetation. This demonstrates that increased aquatic littoral vegetation cover increases the overall importance of the littoral to whole-lake PP in highly humic lakes. Littoral NPP also correlated strongly with littoral O 2 saturation, and the continuously measured O 2 revealed substantial temporal variation in O 2 saturation, particularly in the littoral zone. Whole-lake gross primary production:community respiration (GPP:CR) ratios revealed that

  9. 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

  10. 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.

  11. Effects of a chronic lower range of triclosan exposure to a stream mesocosm community

    Science.gov (United States)

    Nietch, C.T.; Quinlan, E.L.; Lazorchak, J.; Impellitteri, C.; Raikow, D.; Walters, David M.

    2013-01-01

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is an antimicrobial found in consumer soaps and toothpaste. It is in treated wastewater effluents at low part per billion concentrations, representing a potentially chronic exposure condition for biota inhabiting receiving streams. A naturally colonized benthos was created using flow-through indoor mesocosms. Then the benthic communities were dosed to achieve different in-stream triclosan concentrations (Control, 0.1, 0.5, 1.0, 5.0, and 10 µg/L) for 56 days. Water quality parameters and endpoints from bacteria to macroinvertebrates plus interacting abiotic components were measured. Effects of triclosan on specific microbial endpoints were observed at all doses, including an effect on litter decomposition dynamics at doses 1.0 µg/L and higher. Resistance of periphytic bacteria to triclosan significantly increased in doses 0.5 µg/L and above. By the end of dosing, the antimicrobial appeared to stimulate the stream periphyton at the three lowest doses while the two highest doses exhibited decreased stocks of periphyton, including significantly lower bacteria cell densities, and cyanobacteria abundance compared to the control. Beside an effect on benthic ostracods, the changes that occurred in the periphyton did not translate to significant change in the colonizing nematodes, the macroinvertebrate community as a whole, or other measurements of stream function. The results shed light on the role a low, chronic exposure to triclosan may play in effluent dominated streams.

  12. 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

  13. The importance of groundwater to the seasonal variation in nutrients and eulittoral periphyton biomass in the ultra-oligotrophic Lake Tahoe

    Science.gov (United States)

    Naranjo, R. C.; Niswonger, R. G.; Smith, D. W.; Rosenberry, D. O.; Chandra, S.

    2017-12-01

    Understanding the transformation and fate of nutrients in groundwater and surface waters is of critical importance for protecting and managing water resources in ultra-oligotrophic lake systems. In this investigation, we collected nutrient samples from groundwater and surface water during a 9-month monitoring period in Lake Tahoe to evaluate the timing and availability of nutrients in the nearshore zone. We estimated seasonal groundwater discharge using continuous hydraulic-head measurements in piezometers placed in the eulittoral zone sediments. Groundwater discharge rates also were measured directly during a 4-day period using seepage meters. Periphyton biomass measured from substrates and underwater photographs were used to correlate seasonal growth with timing of nutrient availability. Results of this study indicate that groundwater and nutrient discharge to Lake Tahoe is highly variable and is driven by seasonal changes in recharge within the watershed and lake stage. During the early period of monitoring, groundwater discharge was enhanced by the seasonally-low lake stage and episodic recharge caused by precipitation falling as rain in the watershed. Wind generated waves appeared to increase groundwater discharge rates between 0.2 m and 10 m offshore. Average groundwater discharge rate for all transects ranged from -1.0 x 10-2 to 0.8 m/d, with an average of 0.08 m/d, where positive values indicate seepage into the lake. The rates measured with seepage meters along the swash zone ranged from 1.4 x 10-2 to 2.9 m/d, with an average of 0.4 m/d. Nitrate and phosphorus concentrations exhibited seasonal variations and were greater in groundwater than in Lake Tahoe and Ward Creek. Increases in dissolved phosphorus and nitrate in the lake during winter is attributed to groundwater discharge and correlates to increases in periphyton biomass associated with a winter bloom. The results indicate that recharge within the watershed and resulting groundwater and nutrient

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

    OpenAIRE

    Fernandes, V. O.; Esteves, F. A.

    2003-01-01

    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...

  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. 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.

  17. 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.

  18. 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)

    V. O. Fernandes

    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.

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

    Science.gov (United States)

    Fernandes, V O; Esteves, F A

    2003-05-01

    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, heteroautotrophic, 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.

  20. 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.

  1. The disturbance-driven changes of periphytic algal communities in a Danubian floodplain lake

    Directory of Open Access Journals (Sweden)

    Žuna Pfeiffer T.

    2015-01-01

    Full Text Available Disturbance event-driven changes in periphytic algal communities were studied in a Danubian floodplain using artificial substrata (glass slides. The hydrological regime of the river-floodplain system strongly influenced the physical and chemical environment of the investigated lake. Directional changes in the algal communities, demonstrated by the results of non-metric multidimensional scaling, indicated three distinct phases in periphyton development. Strong seasonal influences in the initial accrual phase favored diatom dominance in spring and rapid development of a community composed of filamentous and stalk-forming chlorophytes towards “climax” in summer. Macrophyte and metaphyton stands spreading represented a physical constraint for periphytic algal development. Irrespective of periphyton age and structure, the onset of disturbances resulted in an immediate decrease in periphytic biomass. Disturbances deeply transformed algal communities, whereas the morpho-functional properties of algal species were found to be decisive in community adaptations to altered environmental conditions. Tightly attached and stalk forming diatoms were shown to have an ability to resist and quickly recover from physical disturbance. Our results highlight the necessity for further development of the morpho-functional classification of periphytic algae, which will contribute to more precise evaluations of disturbance-driven events in freshwater ecosystems.

  2. Benthic algal communities : recovery from experimental acidification

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.A.; Findlay, D.L.; Kasian, S.E.M. [Fisheries and Oceans Canada, Winnipeg, MB (Canada). Freshwater Inst.; Baulch, H.M. [Fisheries and Oceans Canada, Winnipeg, MB (Canada); Trent Univ., Peterborough, ON (Canada); Armstrong, L.M. [Ducks Unlimited Canada, Stonewall, MB (Canada). Inst. for Wetland and Waterfowl Research; McNicol, D.K. [Canadian Wildlife Service, Ottawa, ON (Canada); Vinebrooke, R.D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences

    2009-11-15

    This study evaluated the hypothesis that chemical recovery promotes the rapid recovery of benthic algal communities in formerly acidified lakes. The study was conducted at an experimental lake in Ontario over a 10 year period of pH recovery that followed a 10 year period of experimental acidification from a pH of 6.7 to 4.5. A reference lake in the region was also studied to account for regional changes during the study period. Changes in the epilithon on rock surfaces included lower cyanobacterial biomass following the acidification as well as increases in diatoms and greens. Acidification-induced increases in respiration prevented epilithic metabolic recovery. Prior declines in photosynthesis were reversed. Blooms of metaphytic filamentous green algae with a higher pH occurred during the recovery period. The recovery of many aggregate functional and taxonomic properties lagged behind reductions in acidity. Incomplete chemical recovery and the absence of functionally important biota were attributed to incomplete algal recovery at the lake. 59 refs., 2 tabs., 8 figs.

  3. Relations of Principal Components Analysis Site Scores to Algal-Biomass, Habitat, Basin-Characteristics, Nutrient, and Biological-Community Data in the Whitewater River and East Fork White River Basins, Indiana, 2002

    Science.gov (United States)

    Caskey, Brian J.; Frey, Jeffrey W.; Lowe, B. Scott

    2007-01-01

    Data were gathered from May through September 2002 at 76 randomly selected sites in the Whitewater River and East Fork White River Basins, Indiana, for algal biomass, habitat, nutrients, and biological communities (fish and invertebrates). Basin characteristics (land use and drainage area) and biolog-ical-community attributes and metric scores were determined for the basin of each sampling site. Yearly Principal Compo-nents Analysis site scores were calculated for algal biomass (periphyton and seston). The yearly Principal Components Analysis site scores for the first axis (PC1) were related using Spearman's rho to the seasonal algal-biomass, basin-charac-teristics, habitat, seasonal nutrient, and biological-community attribute and metric score data. The periphyton PC1 site score was not significantly related to the nine habitat or 12 nutrient variables examined. One land-use variable, drainage area, was negatively related to the periphyton PC1. Of the 43 fish-community attributes and metrics examined, the periphyton PC1 was negatively related to one attribute (large-river percent) and one metric score (car-nivore percent metric score). It was positively related to three fish-community attributes (headwater percent, pioneer percent, and simple lithophil percent). The periphyton PC1 was not statistically related to any of the 21 invertebrate-community attributes or metric scores examined. Of the 12 nutrient variables examined two were nega-tively related to the seston PC1 site score in two seasons: total Kjeldahl nitrogen (July and September), and TP (May and September). There were no statistically significant relations between the seston PC1 and the five basin-characteristics or nine habitat variables examined. Of the 43 fish-community attributes and metrics examined, the seston PC1 was positively related to one attribute (headwater percent) and negatively related to one metric score (large-river percent metric score) . Of the 21 invertebrate-community attributes

  4. 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.

  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. Ecological and evolutionary effects of stickleback on community structure.

    Science.gov (United States)

    Des Roches, Simone; Shurin, Jonathan B; Schluter, Dolph; Harmon, Luke J

    2013-01-01

    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.

  7. 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

  8. 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.

  9. Shifts of community composition and population density substantially affect ecosystem function despite invariant richness.

    Science.gov (United States)

    Spaak, Jurg W; Baert, Jan M; Baird, Donald J; Eisenhauer, Nico; Maltby, Lorraine; Pomati, Francesco; Radchuk, Viktoriia; Rohr, Jason R; Van den Brink, Paul J; De Laender, Frederik

    2017-10-01

    There has been considerable focus on the impacts of environmental change on ecosystem function arising from changes in species richness. However, environmental change may affect ecosystem function without affecting richness, most notably by affecting population densities and community composition. Using a theoretical model, we find that, despite invariant richness, (1) small environmental effects may already lead to a collapse of function; (2) competitive strength may be a less important determinant of ecosystem function change than the selectivity of the environmental change driver and (3) effects on ecosystem function increase when effects on composition are larger. We also present a complementary statistical analysis of 13 data sets of phytoplankton and periphyton communities exposed to chemical stressors and show that effects on primary production under invariant richness ranged from -75% to +10%. We conclude that environmental protection goals relying on measures of richness could underestimate ecological impacts of environmental change. © 2017 The Authors Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  10. 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

  11. 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

  12. Direct and indirect effects of the glyphosate formulation Glifosato Atanor® on freshwater microbial communities.

    Science.gov (United States)

    Vera, María Solange; Di Fiori, Eugenia; Lagomarsino, Leonardo; Sinistro, Rodrigo; Escaray, Roberto; Iummato, María Mercedes; Juárez, Angela; Ríos de Molina, María del Carmen; Tell, Guillermo; Pizarro, Haydée

    2012-10-01

    Glyphosate-based formulations are among the most widely used herbicides in the world. The effect of the formulation Glifosato Atanor(®) on freshwater microbial communities (phytoplankton, bacterioplankton, periphyton and zooplankton) was assessed through a manipulative experiment using six small outdoor microcosms of small volume. Three of the microcosms were added with 3.5 mg l(-1) of glyphosate whereas the other three were left as controls without the herbicide. The treated microcosms showed a significant increase in total phosphorus, not fully explained by the glyphosate present in the Glifosato Atanor(®). Therefore, part of the phosphorus should have come from the surfactants of the formulation. The results showed significant direct and indirect effects of Glifosato Atanor(®) on the microbial communities. A single application of the herbicide caused a fast increase both in the abundance of bacterioplankton and planktonic picocyanobacteria and in chlorophyll a concentration in the water column. Although metabolic alterations related to oxidative stress were induced in the periphyton community, the herbicide favored its development, with a large contribution of filamentous algae typical of nutrient-rich systems, with shallow and calm waters. An indirect effect of the herbicide on the zooplankton was observed due to the increase in the abundance of the rotifer Lecane spp. as a consequence of the improved food availability given by picocyanobacteria and bacteria. The formulation affected directly a fraction of copepods as a target. It was concluded that the Glifosato Atanor(®) accelerates the deterioration of the water quality, especially when considering small-volume water systems.

  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. Isolation of Novel Extreme-Tolerant Cyanobacteria from a Rock-Dwelling Microbial Community by Using Exposure to Low Earth Orbit▿ †

    Science.gov (United States)

    Olsson-Francis, Karen; de la Torre, Rosa; Cockell, Charles S.

    2010-01-01

    Many cyanobacteria are known to tolerate environmental extremes. Motivated by an interest in selecting cyanobacteria for applications in space, we launched rocks from a limestone cliff in Beer, Devon, United Kingdom, containing an epilithic and endolithic rock-dwelling community of cyanobacteria into low Earth orbit (LEO) at a height of approximately 300 kilometers. The community was exposed for 10 days to isolate cyanobacteria that can survive exposure to the extreme radiation and desiccating conditions associated with space. Culture-independent (16S rRNA) and culture-dependent methods showed that the cyanobacterial community was composed of Pleurocapsales, Oscillatoriales, and Chroococcales. A single cyanobacterium, a previously uncharacterized extremophile, was isolated after exposure to LEO. We were able to isolate the cyanobacterium from the limestone cliff after exposing the rock-dwelling community to desiccation and vacuum (0.7 × 10−3 kPa) in the laboratory. The ability of the organism to survive the conditions in space may be linked to the formation of dense colonies. These experiments show how extreme environmental conditions, including space, can be used to select for novel microorganisms. Furthermore, it improves our knowledge of environmental tolerances of extremophilic rock-dwelling cyanobacteria. PMID:20154120

  16. 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.

  17. Preliminary investigations on epilithic cyanophytes from a Roman Necropolis

    Czech Academy of Sciences Publication Activity Database

    Albertano, P.; Kováčik, Lubomír; Marvan, Petr; Grilli Caiola, M.

    1994-01-01

    Roč. 105, č. 75 (1994), s. 118-124 ISSN 0342-1120. [Symposium of the International Association for Cyanophyte Research /12./. Sjöarp, 04.08.1994-14.08.1994] R&D Projects: GA AV ČR IAA6005502 Impact factor: 0.818, year: 1994

  18. 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 (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 organism distribution and abundance. Community resistance and resilience were unrelated to shifts in community assembly, suggesting that they are mostly evolutionary properties of ecosystems as populations adapt to changing environmental (disturbance regimes) and biotic (novel colonists) conditions. As these systems show behaviors similar to dispersal-limited ecosystems, a long-term perspective is required for management actions targeted toward regulated and fragmented rivers.

  19. Mixed messages from benthic microbial communities exposed to nanoparticulate and ionic silver: 3D structure picks up nano-specific effects, while EPS and traditional endpoints indicate a concentration-dependent impact of silver ions.

    Science.gov (United States)

    Kroll, Alexandra; Matzke, Marianne; Rybicki, Marcus; Obert-Rauser, Patrick; Burkart, Corinna; Jurkschat, Kerstin; Verweij, Rudo; Sgier, Linn; Jungmann, Dirk; Backhaus, Thomas; Svendsen, Claus

    2016-03-01

    Silver nanoparticles (AgNP) are currently defined as emerging pollutants in surface water ecosystems. Whether the toxic effects of AgNP towards freshwater organisms are fully explainable by the release of ionic silver (Ag(+)) has not been conclusively elucidated. Long-term effects to benthic microbial communities (periphyton) that provide essential functions in stream ecosystems are unknown. The effects of exposure of periphyton to 2 and 20 μg/L Ag(+) (AgNO3) and AgNP (polyvinylpyrrolidone stabilised) were investigated in artificial indoor streams. The extracellular polymeric substances (EPS) and 3D biofilm structure, biomass, algae species, Ag concentrations in the water phase and bioassociated Ag were analysed. A strong decrease in total Ag was observed within 4 days. Bioassociated Ag was proportional to dissolved Ag indicating a rate limitation by diffusion across the diffusive boundary layer. Two micrograms per liter of AgNO3 or AgNP did not induce significant effects despite detectable bioassociation of Ag. The 20-μg/L AgNO3 affected green algae and diatom communities, biomass and the ratio of polysaccharides to proteins in EPS. The 20-μg/L AgNO3 and AgNP decreased biofilm volume to about 50 %, while the decrease of biomass was lower in 20 μg/L AgNP samples than the 20-μg/L AgNO3 indicating a compaction of the NP-exposed biofilms. Roughness coefficients were lower in 20 μg/L AgNP-treated samples. The more traditional endpoints (biomass and diversity) indicated silver ion concentration-dependent effects, while the newly introduced parameters (3D structure and EPS) indicated both silver ion concentration-dependent effects and effects related to the silver species applied.

  20. Gradients of intertidal primary productivity around the coast of South Africa and their relationships with consumer biomass

    CSIR Research Space (South Africa)

    Bustamante, RH

    1995-05-01

    Full Text Available The structure of rocky intertidal communities may be influenced by large-scale patterns of productivity. This study examines the in situ rates of production by intertidal epilithic microalgae (chlorophyll a production per unit area per month...

  1. Community Development through Community Education.

    Science.gov (United States)

    Palmer, Jim

    1982-01-01

    Cites ERIC documents describing the community education and development programs of two-year colleges. Documents cover building a neighborhood coalition, an approach to marketing vocational programs, community education and development, and educational alternatives. (DMM)

  2. 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.

  3. The effects of physicochemical variables and tadpole assemblages on microalgal communities in freshwater temporary ponds through an experimental approach.

    Science.gov (United States)

    Zongo, Bilassé; Boussim, Joseph I

    2015-01-01

    In freshwater systems, microalgae are the major biomass of microorganisms. They occur in ecosystems that are largely structured by the climatic regime, the physical and chemical environments with which they interact, and the biological interactions that occur within them. Amphibian larvae are most present in standing water habitats where they are important primary and secondary consumers and even predators. Studies conducted in America and Europe have shown that tadpoles play an important role in the regulation of the algal community structure and water quality in ecosystems. This article aimed to study the effects of the physicochemical variables and tadpole assemblages of four species on microalgae in artificial freshwater ponds using an experimental approach in the Pendjari area, a flora and fauna reserve located in the extreme north-west of Benin. The species of phytoplankton and periphyton recorded in ponds were among the taxonomical groups of chlorophytes, cyanophytes, euglenophytes, diatoms and dinoflagellates. Chlorophytes were the dominant group in the algal communities. Physicochemical variables affected the biomass of the different communities of algae in temporary freshwater ponds. Transparency and pond size were the most determinative variables of the structure of microalgae communities in ponds. Tadpoles of Kassina fusca, Ptychadena. bibroni, and Phrynomantis microps were important for the regulation of the water quality and algal community structure by grazing and filter-feeding. A decrease in the tadpole population in the artificial temporary ponds due to predation by carnivorous tadpoles of Hoplobatrachus occipitalis caused a disturbance of the algal community structure. This means that the decline of the amphibian population will critically lead to the impoverishment of ecosystems, thereby negatively influencing aquatic and terrestrial ecosystems.

  4. 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

  5. Community Drive

    DEFF Research Database (Denmark)

    Magnussen, Rikke

    2018-01-01

    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...... of living in the area. The paper discusses potentials and pitfalls of designing community-driven science gaming environments and how results from previous studies can form the project Community Drive....

  6. 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

  7. 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 and explo......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...

  8. 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...... clique thresholds for each of the nonoverlapping node sets in the bipartite network...

  9. 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...

  10. 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.

  11. Moral communities.

    Science.gov (United States)

    Chambers, David W

    2006-11-01

    This article explores the twin issues of whether organizations can act as ethical agents and what it means to exert moral influence over others. A discursive perspective is advanced that characterizes ethics as the action of communities based on promises. The received view of ethics as either the universal principles or individual responsibility is criticized as inadequate. Moral influence within community is considered under the various headings of democracy, office, brotherhood, agency, witness, and promise making. Moral influence among communities can include the damaging methods of "the superior position," coercion and misrepresentation, and appeal to third parties and the sound methods of rhetoric and promise making.

  12. 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...

  13. COMMUNITY OPHTHALMOLOGY

    African Journals Online (AJOL)

    2016-11-04

    [2] However, in Nigeria PHC is .... why patients with cataract refuse free surgery: the influence of rumours in Kenya. Trop Med Int Health .... Low vision in persons aged 50 and above in the onchocercal endemic communities of ...

  14. 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

  15. 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.

  16. COMMUNITY ENGAGEMENT

    African Journals Online (AJOL)

    Test

    COMMUNITY ENGAGEMENT. International Day of the. Older Person 2009. Yaseen Ally, Deanne Goldberg and Royal Lekoba. UNISA Institute for Social and Health Sciences. Mohamed Seedat. UNISA Institute for Social and Health Sciences and. MRC–UNISA Crime, Violence and Injury Lead Programme. Shahnaaz Suffla.

  17. Interfirm communities

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten

    2012-01-01

    Strong and trust-based ties are usually related to homogeneous and complex knowledge, while weak ties are associated with heterogeneous and simple knowledge. Interfirm communities have been shown to depend on trust-based ties, while also relying on getting access to heterogeneous knowledge. These...

  18. 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....

  19. 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.

  20. Designed communities?

    DEFF Research Database (Denmark)

    Stender, Marie

    2013-01-01

    as an identity unit. In Ørestad residents thus tend to identify by the name of the house they live in, rather than by the street name. These residential spaces may thus be seen as promoting micro-urban entities, as social and urban life is designed and staged within the residential complex, and activities...... of these designed communities: What social life is promoted in such recent architectural visions? And to what extent can the social life and identity of a place actually be designed? The paper discusses these questions based on a fieldwork in three new housing complexes in the Copenhagen Region: The A......-house by architect Carsten Holgaard, the 8-house by BIG, and Lange Eng (The Long Meadow) by Dorte Mandrup. Rather than taking the perspective of either architect or user, the fieldwork has ethnographically traced the entire process from design to occupancy. The aim is to explore how the social life and identity...

  1. 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…

  2. 8 Periphyton Associated with Nymphaea lotus Linn.cdr

    African Journals Online (AJOL)

    Administrator

    Ted Y. Annang* and Akua M. Addo-Boadu. Institute for Environment and Sanitation Studies, P. O. Box LG 209, Legon .... Chrysophyceae. Chromulinales. Phaester. 9. 8. Ochromonadales. Mallomonas. 8. 11. Cyanophyta. Cyanophyceae. Chrococcales. Coelosphaerium. 1. 3. Oscillatoriales. Anabaena. 2. 3. Microcoleus. 1. 0.

  3. Periphyton Associated with Nymphaea lotus Linn. in Two Different ...

    African Journals Online (AJOL)

    ... phyla (Chlorophyta, Cryptophyta, Crysophyta, Cyanophyta and Euglenophyta) were observed. The Cyanophyta and the Chlorophyta, respectively, dominated the population in the Kpong head-pond and the Odaw stream. A far greater population of diatoms family (Bacillariophyceae) was found in the Odaw stream than in ...

  4. 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…

  5. 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

  6. 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...

  7. 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...

  8. Administration for Community Living

    Science.gov (United States)

    ... Public Input Working Together, in Our Communities The Administration for Community Living was created around the fundamental ... Meals on Wheels America - November 16, 2017 The Administration for Community Living recently awarded a three-year ...

  9. Nganyi Community Resource Centre: Community radio station ...

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

    2016-05-04

    Nganyi Community Resource Centre: Community radio station broadcasts weather forecasts, climate change news to farmers in Kenya. May 04, 2016. Image ... To boost access, KMS distributed radio handsets to communities with a built-in solar power generator and wind-up system. KMS senior assistant director Samuel ...

  10. 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…

  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. 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.

  13. Bayesian community detection

    DEFF Research Database (Denmark)

    Mørup, Morten; Schmidt, Mikkel N

    2012-01-01

    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...

  14. 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

  15. 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.

  16. 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

  17. 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…

  18. 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 ...

  19. Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria.

    Science.gov (United States)

    Mustoe, George E

    2018-01-15

    A sandstone outcrop exposed to freshwater seepage supports a diverse assemblage of photosynthetic microbes. Dominant taxa are two cyanophytes ( Oscillatoria sp., Rivularia sp.) and a unicellular green alga ( Palmellococcus sp.). Less abundant taxa include a filamentous green alga, Microspora , and the desmid Cosmarium . Biologic activity is evidenced by measured levels of chlorophyll and lipids. Bioassay methods confirm the ability of these microbes to dissolve and metabolize Fe from ferruginous minerals. Chromatographic analysis reveals citric acid as the likely chelating agent; this low molecular weight organic acid is detectable in interstitial fluid in the sandstone, measured as 0.0756 mg/mL. Bioassays using a model organism, Synechoccus elongates strain UTEX 650, show that Fe availability varies among different ferruginous minerals. In decreasing order of Fe availability: magnetite > limonite > biotite > siderite > hematite. Biotite was selected for detailed study because it is the most abundant iron-bearing mineral in the sandstone. SEM images support the microbiologic evidence, showing weathering of biotite compared to relatively undamaged grains of other silicate minerals.

  20. Epilithic biofilms in Saint Callixtus Catacombs (Rome) harbour a broad spectrum of Acidobacteria.

    Science.gov (United States)

    Zimmermann, Johannes; Gonzalez, Juan M; Saiz-Jimenez, Cesareo

    2006-01-01

    The phylum Acidobacteria is broadly represented in a variety of environments as reported during microbial molecular surveys. This study represents the first attempt to analyze the diversity of Acidobacteria in Roman Catacombs (Rome, Italy). Both 16S and 23S rRNA gene sequences were used to confirm the affiliation within different acidobacterial subgroups. The results showed Acidobacteria belonging to subgroups 3, 4, 6, 9, and 10 in the analyzed samples. The presence of acidobacterial sequences in biodeteriorating biofilms in Roman Catacombs suggest they could participate in this negative process, most likely in cooperation with other microbial groups.

  1. 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

  2. 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.

  3. 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...

  4. 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...

  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. A la Carte Community

    DEFF Research Database (Denmark)

    Gundelach, Peter; Brincker, Benedikte

    2010-01-01

    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...... 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...... 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...

  7. Bayesian community detection.

    Science.gov (United States)

    Mørup, Morten; Schmidt, Mikkel N

    2012-09-01

    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. 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...

  9. THE RELATIONSHIP AMONG COMMUNITY SPIRIT, COMMUNITY IDENTIFICATION, AND COMMUNITY LOYALTY OF ONLINE SPORTS COMMUNITY USER

    OpenAIRE

    Jae-Keun Yang

    2015-01-01

    The purpose of the study is to examine the relationship among community spirit, community identification, and community loyalty of online sports community user. To accomplish the purpose of the study, adult users of "N" research engine are subjected to questionnaire. Based on convenience sampling, 383 questionnaires are used for final data analysis. By utilizing SPSS 21.0, frequency analysis, exploratory factor analysis, reliability analysis, simple regression analysis and multiple regression...

  10. Communities in University Mathematics

    Science.gov (United States)

    Biza, Irene; Jaworski, Barbara; Hemmi, Kirsti

    2014-01-01

    This paper concerns communities of learners and teachers that are formed, develop and interact in university mathematics environments through the theoretical lens of "Communities of Practice." From this perspective, learning is described as a process of participation and reification in a community in which individuals belong and form…

  11. Community forestry in Nederland

    NARCIS (Netherlands)

    Lambregts, L.; Wiersum, K.F.

    2002-01-01

    Uitleg over de oorsprong en betekenis van het gegrip 'community forestry', en een inventarisatie van de verschillende vormen van community forestry die in Nederland voorkomen en de motieven voor deelname aan community forestry activiteiten. Vooral twee categorieën van bosbeheer worden beschouwd als

  12. 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…

  13. 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......-cise is to determine the degree to which the concepts of discourse commu-nity and community of practice are suitable for investigating the social and organizational context of text and knowledge production. Finally, the paper examines the explanatory value of the two concepts for analyzing text and knowledge...

  14. 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....

  15. Community 21: Digital toolbox for sustainable communities

    Directory of Open Access Journals (Sweden)

    Nick Gant

    2010-11-01

    Full Text Available This article will describe the 'Toolbox for the 21st Century Village' action research project and outline the critical research contexts that underpin its development as an online informatics and social engagement tool aimed at facilitating understanding, sharing and planning of integrated sustainability by individual communities. This will include exposing the context of ‘mis-communication’ of sustainability issues in society by visual culture, the media and politics. The article argues that this has served to alienate, demoralise and disenfranchise many individuals and communities. Being rural does not necessarily mean being ‘green’ and the article will describe the ‘green dichotomy’ and how rural behaviours are disproportionately dependent on natural resources and as a consequence are ‘less sustainable’, despite relative autonomy and community potential to make significant gains. The article will also unpack and explore how the loaded term sustainability only serves to divide and detract as a polemic and absolute term; whereas self-sufficiency is a demonstrable concern of vulnerable rural communities; a by-product of which can be genuine and valued, measurable and meaningful sustainable development. The above provides a contextual backdrop and rationale for the formation of a project that enables communities to frame their own concerns and envision themselves and their problems and responses as part of a larger system. The project is developed around an experimental online content management system (CMS platform that will facilitate sustainable development through envisioning, action planning and networking – connecting the ‘knots in the net’ of an active patchwork of ‘multi-local communities’. The platform design will provide methodology, process and capacity to enable reconciliation between the manifold concerns of social, economic and environmental sustainability whilst providing community facilitators with new

  16. 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)

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

    Directory of Open Access Journals (Sweden)

    Sabine Hilt

    2018-02-01

    Full Text Available 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

  18. 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

  19. Communities and community genetics in Ethiopia

    Science.gov (United States)

    Tadesse, Luche; Tafesse, Fikru; Hamamy, Hanan

    2014-01-01

    The rates of congenital and genetic disorders in low and middle income countries are similar or might be higher than in high income countries due to a multitude of risk factors and the dearth of community genetic services. To direct effective preventive, diagnostic and counseling services, collecting data on the incidence and prevalence of various congenital and genetic disorders and their risk factors is a pre-requisite for establishing genetic services at the community level and mainly at the primary health care setting. This brief review is meant to assess the available epidemiological data in Ethiopia pertaining to congenital and genetic disorders on which the future community genetic services could be built. Existing epidemiological data on congenital and genetic disorders in Ethiopia is limited, and the few studies conducted revealed that folate and iodine deficiencies are prevalent among women in the reproductive age. Pregnant women's infection with syphilis and rubella is prevailing. Based on available data, cleft lip and palate, congenital heart diseases, club-foot, and gastro-intestinalmalformations are the most common birth defects in Ethiopia. Community based studies to accurately demonstrate the incidence and prevalence levels of these disorders are almost unavailable. To plan for organization and implementation of community genetic services at the primary health care level in Ethiopia, conducting standardized epidemiological studies is currently highly recommended. PMID:25404975

  20. 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

  1. Mining online community data

    DEFF Research Database (Denmark)

    Christensen, Kasper; Liland, Kristian Hovde; Kvaal, Knut

    2017-01-01

    Ideas are essential for innovation and for the continuous renewal of a firm’s product offerings. Previous research has argued that online communities contain such ideas. Therefore, online communities such as forums, Facebook groups, blogs etc. are potential gold mines for innovative ideas that can...... be used for boosting the innovation performance of the firm. However, the nature of online community data makes idea detection labor intensive. As an answer to this problem, research has shown that it might be possible to detect ideas from online communities, automatically. Research is however, yet...... to provide an answer to what is it that makes such automatic idea detection possible? Our study is based on two datasets from dialogue between members of two distinct online communities. The first community is related to beer. The second is related to Lego. We generate machine learning classifiers based...

  2. Career guidance in communities

    DEFF Research Database (Denmark)

    Thomsen, Rie

    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...... 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...

  3. 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.

  4. Differential impact of Limnoperna fortunei-herbicide interaction between Roundup Max® and glyphosate on freshwater microscopic communities.

    Science.gov (United States)

    Gattás, F; Vinocur, A; Graziano, M; Dos Santos Afonso, M; Pizarro, H; Cataldo, D

    2016-09-01

    Multiple anthropogenic stressors act simultaneously on the environment, with consequences different from those caused by single-stressor exposure. We investigated how the combination of the invasive mussel Limnoperna fortunei and a widely applied herbicide, Roundup Max®, affected freshwater microscopic communities and water quality. Further, we compared these results with those induced by the combination of the mussel and technical-grade glyphosate. We carried out a 34-day experiment in outdoor mesocosms, applying the following six treatments: 6 mg L(-1) of technical-grade glyphosate (G), the equivalent concentration of glyphosate in Roundup Max® (R), 100 mussels (M), the combination of mussels and herbicide either in the technical-grade or formulated form (MG and MR, respectively), and control (C). Herbicides significantly increased total phosphorus in water; R and MR showed greater initial total nitrogen and ammonium. R increased picoplankton abundance and caused an eightfold increase in phytoplankton, with high turbidity values; G had a lower effect on these variables. Herbicide-mussel combination induced an accelerated dissipation of glyphosate in water (MG 6.36 ± 0.83 mg G g DW(-1) day(-1) and MR 5.16 ± 1.26 mg G g DW(-1) day(-1)). A synergistic effect on ammonium was observed in MR but not in MG. MR and MG had an antagonistic effect on phytoplankton, which showed a drastic reduction due to grazing, as revealed by M. We provide evidence of differential effects of Roundup Max® and technical-grade glyphosate over water quality and microscopic communities, and in combination with mussels. However, in the combination of mussels and herbicides, mussels seem to play a leading role. In the presence of L. fortunei, the effects of higher nutrient availability provided by herbicides addition were counteracted by the filtration activity of mussels, which released nutrients, grazed on picoplankton and phytoplankton, and boosted the development of other

  5. 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.

  6. 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)

  7. 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.

  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. Learning Community and Nonlearning Community Students in a Midwestern Community College

    Science.gov (United States)

    Laanan, Frankie Santos; Jackson, Dimitra Lynette; Stebleton, Michael J.

    2013-01-01

    The research on learning communities has focused primarily on students at four-year colleges and universities. There is a dearth of studies that examine learning communities in community colleges. The purpose of this comparative study was to conduct an analysis of learning community and nonlearning community students in a community college located…

  10. Light increases energy transfer efficiency in a boreal stream.

    Science.gov (United States)

    Lesutienė, Jūratė; Gorokhova, Elena; Stankevičienė, Daiva; Bergman, Eva; Greenberg, Larry

    2014-01-01

    Periphyton communities of a boreal stream were exposed to different light and nutrient levels to estimate energy transfer efficiency from primary to secondary producers using labeling with inorganic (13)C. In a one-day field experiment, periphyton grown in fast-flow conditions and dominated by opportunistic green algae were exposed to light levels corresponding to sub-saturating (forest shade) and saturating (open stream section) irradiances, and to N and P nutrient additions. In a two-week laboratory experiment, periphyton grown in low-flow conditions and dominated by slowly growing diatoms were incubated under two sub-saturating light and nutrient enrichment levels as well as grazed and non-grazed conditions. Light had significant positive effect on (13)C uptake by periphyton. In the field experiment, P addition had a positive effect on (13)C uptake but only at sub-saturating light levels, whereas in the laboratory experiment nutrient additions had no effect on the periphyton biomass, (13)C uptake, biovolume and community composition. In the laboratory experiment, the grazer (caddisfly) effect on periphyton biomass specific (13)C uptake and nutrient content was much stronger than the effects of light and nutrients. In particular, grazers significantly reduced periphyton biomass and increased biomass specific (13)C uptake and C:nutrient ratios. The energy transfer efficiency, estimated as a ratio between (13)C uptake by caddisfly and periphyton, was positively affected by light conditions, whereas the nutrient effect was not significant. We suggest that the observed effects on energy transfer were related to the increased diet contribution of highly palatable green algae, stimulated by higher light levels. Also, high heterotrophic microbial activity under low light levels would facilitate energy loss through respiration and decrease overall trophic transfer efficiency. These findings suggest that even a small increase in light intensity could result in community

  11. Community Media Handbook.

    Science.gov (United States)

    Zelmer, A. C. Lynn

    Basic information on media forms which are commonly encountered by community groups is presented. The work as a whole is designed to serve as a reference manual for community organizations and volunteer groups which are inexperienced with respect to media and which lack the resources or the desire to hire professional experts; the emphasis…

  12. Video in Community Development.

    Science.gov (United States)

    Hopkins, John; And Others

    1973-01-01

    The portable videotape recorder has made television a fast and cheap medium which can be used in social change and community development. This collection provides a practical handbook for planning a community development project in the form of detailed references and a programed test. Techniques for setting up a project and working with the…

  13. ICT for Community Energy

    NARCIS (Netherlands)

    Weerdt, C.A. van der; Carmichael, R.; Palm, B

    2016-01-01

    Community energy initiatives are becoming more and more widespread. For them to be successful and flourish, engagement from people in the community is a prerequisite. ICT can provide the means to support engagement, by helping people to assess the impact and benefits of a CE project and by capturing

  14. 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,…

  15. Open source community organization

    CSIR Research Space (South Africa)

    Molefe, Onkgopotse M

    2009-05-01

    Full Text Available mechanism Style Scilab Debian Ubuntu Apache Consortium of stakeholders and partners Governed by committee, community manager Elected leadership Strong constitution Democracy (each contributor has equal an vote) Self appointed leader Councils... contributors and users – Governance and coordination strategy, leadership styles, community constitution – Growth and maintenance Session 8e, 07 May 2009 IST-Africa 2009 Copyright 2009...

  16. 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.

  17. 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...

  18. Communities, Cameras, and Conservation

    Science.gov (United States)

    Patterson, Barbara

    2012-01-01

    Communities, Cameras, and Conservation (CCC) is the most exciting and valuable program the author has seen in her 30 years of teaching field science courses. In this citizen science project, students and community volunteers collect data on mountain lions ("Puma concolor") at four natural areas and public parks along the Front Range of Colorado.…

  19. 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...

  20. 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…

  1. Community College Governance.

    Science.gov (United States)

    Wyoming Community Coll. Commission, Cheyenne.

    This report presents the findings of the state legislature's Management Audit Committee's review of the structure and governance of community colleges in Wyoming, as requested by the Legislature's Management Council in September 1998. In trying to answer questions about the structure of community college governance, the tensions present in the…

  2. Communicating with the Community

    Science.gov (United States)

    Openlander, Stuart L.

    1973-01-01

    One of the most difficult tasks in education today is effective communications between the school administration and the community. The Parma School District (Ohio) uses slide presentations and color films to get its message across to community groups. (Author/WM)

  3. 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…

  4. Involving the Community

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

    How can two-way communication enhance community participation in research and development initiatives and improve the capacity of communities to participate in the ...... Resistance to change and the force of local customs, habits and taboos are other cultural aspects that can often pose significant obstacles.

  5. A Learning Community Simulation

    NARCIS (Netherlands)

    Koné, Malik; Berlanga, Adriana; Sloep, Peter; Koper, Rob

    2007-01-01

    Koné, M., Berlanga, A. J., Sloep, P. B., & Koper, R. (2007). A Learning Community Simulation. In P. Kommers & P. Isaias (Eds.), Proceedings of the IADIS International Conference on Web Based Communities 2007 (pp. 331-335). February, 18-20, 2007, Salamanca, Spain: IADIS Press.

  6. Journalists as Interpretive Communities.

    Science.gov (United States)

    Zelizer, Barbie

    1993-01-01

    Proposes viewing journalists as members of an interpretive community (not a profession) united by its shared discourse and collective interpretations of key public events. Applies the frame of the interpretive community to journalistic discourse about two events central for American journalists--Watergate and McCarthyism. (SR)

  7. 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…

  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. Community and Individuality

    Directory of Open Access Journals (Sweden)

    Martin Andrew

    2014-07-01

    Full Text Available How should lecturers teaching postgraduate creative writing in an online master of arts build and maintain e-community to support and socialize learners? The study proposes that such programs need to attend to writers’ investments in developing identities while promoting socialization and sense of belonging. Grounded in literature on communities of practice, imagined community, and identity, the study draws on social constructivist and poststructuralist insights and contributes to the relatively unexplored area of pedagogy for teaching writing online. The study uses qualitative descriptive analysis to narrate themes from two datasets in the form of a métissage. Data from lecturer-e-moderators and students indicate that strategic e-moderation encourages collaboration and maximizes pedagogical potential in forums. Strategic e-moderation builds a sense of community by fostering critical friendships. The study emphasizes the need for e-moderators to develop participants’ investments in working in communities. The study reveals that although postgraduate writing students come to value learning via critical friendships and communities, they also demand particularized feedback from e-moderators and peers. Findings suggest that students need to develop writing identities and voices can be met by a pedagogical approach that harnesses the potential of community while offering response to individual development. The study concludes that pedagogies of community in teaching writing online need to benefit both collectively and individually. This works when writers apply discipline-specific literacies and professional skills in critiquing peer texts, while responding to feedback from their community of practice, facilitated by e-moderators.

  10. [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

  11. Community response to noise

    Directory of Open Access Journals (Sweden)

    Takashi Yano

    2012-01-01

    Full Text Available Activities from 2008 to 2011 by ICBEN community response to noise team were summarized. That is, individual community-based indexes such as community tolerance Level, Zuricher Fluglarm Index (ZFI and Frankfurter Fluglarm Index (FFI/FNI were newly proposed, differences in railway bonus between Europe and Asia were discussed by a Swedish survey, socio-acoustic surveys were reported from developing countries, and annoyance equivalents and dominant source models were proposed as the adequate combined noise model. Furthermore, not only negative, but also positive aspects of sound were discussed as soundscape studies. Finally, seven items were listed as future team activities.

  12. Community-Engaged Scholarship

    DEFF Research Database (Denmark)

    Barinaga, Ester; Parker, Patricia S.

    2013-01-01

    We are pleased to offer this special issue on community-engaged scholarship. As scholar-activists working for social justice alongside youth of color (Pat) and critical arts activists engaging with stigmatized communities (Ester), we began this project with the intent of gathering a collection...... to this special issue, Schaefer & Rivera) in community-engaged scholarship—issues that emerge at the intersection between the political and the theoretical and which are at the forefront of conversations both inside and outside the traditional boundaries of academe....

  13. 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....

  14. 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;…

  15. 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...

  16. 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.

  17. Growing Data User Communities

    Science.gov (United States)

    Wiggin, B.

    2017-12-01

    Preserving data is not only a technical challenge. Perhaps the best way to protect data is to use it. Grassroots efforts to make research-quality copies of federal data continue to energize communities of data users who often did not previously recognize themselves as open earth data users. Beyond "data rescue" events, the Data Refuge project researches how federal climate and environmental data are used downstream in a variety of local communities and municipal governments to address everyday issues: public health, municipal safety, and even the preservation of cultural heritage assets. Documenting the diverse uses made of open earth data beyond the earth sciences research community grows the community who, in making use of data, also helps to preserve it.

  18. 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...

  19. 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...

  20. SUICIDE IN RURAL COMMUNITY

    OpenAIRE

    Hedge, R. S.

    1980-01-01

    SUMMARY 51 suicides in a rural community of Northern Karnataka were studied for incidence, age and sex distribution, methods adopted for suicides, and causes of suicides. Suicides in rural area did not show any difference from urban suicide pattern.

  1. 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...

  2. Communities ready for takeoff.

    Science.gov (United States)

    Rijkhoff, Sanne A M; Hoard, Season A; Gaffney, Michael J; Smith, Paul M

    2017-01-01

    Although much of the social science literature supports the importance of community assets for success in many policy areas, these assets are often overlooked when selecting communities for new infrastructure facilities. Extensive collaboration is crucial for the success of environmental and economic projects, yet it often is not adequately addressed when making siting decisions for new projects. This article develops a social asset framework that includes social, creative, and human capital to inform site-selection decisions. This framework is applied to the Northwest Advanced Renewables Alliance project to assess community suitability for biofuel-related developments. This framework is the first to take all necessary community assets into account, providing insight into successful site selection beyond current models. The framework not only serves as a model for future biorefinery projects but also guides tasks that depend on informed location selection for success.

  3. New marine community

    Science.gov (United States)

    While exploring the West Florida Escarpment, a steep slope in the Gulf of Mexico several hundred kilometers off the Florida coast, the deep submergence research vessel Alvin chanced upon a well-developed community of marine life akin to that found 7 years ago in the eastern Pacific Ocean.According to the Woods Hole Oceanographic Institution, which operates the submersible and its new tender, the Atlantis II (Eos, November 1, 1983, p. 619), the marine community contains large clams, mussels, crabs, fish, and tube worms like those found at hydrothermal vents in the eastern Pacific. While the east Pacific communities exist at spreading centers, the newly discovered group, which may stretch for almost 2 km at a depth of roughly 3200 km, lies in a passive continental margin. Also, whereas the water around the Pacific hydrothermal vents is much warmer than the surrounding seawater, the water around the new found community is apparently the same temperature as the ambient waters.

  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. Gated community Na Krutci

    Czech Academy of Sciences Publication Activity Database

    Hnídková, Vendula

    2012-01-01

    Roč. 91, č. 12 (2012), s. 750-752 ISSN 0042-4544 Institutional support: RVO:68378033 Keywords : Gated community * Czech contemporary architecture * Kuba Pilař Subject RIV: AL - Art, Architecture , Cultural Heritage

  6. 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...

  7. 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 ...

  8. 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 lea...... in debates about learning, teaching, and education but also in debates about organizational theory, knowledge management, and work-life studies.......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...

  9. ICT for Community Energy

    OpenAIRE

    Weerdt, C.A. van der; Carmichael, R.; Palm, B

    2016-01-01

    Community energy initiatives are becoming more and more widespread. For them to be successful and flourish, engagement from people in the community is a prerequisite. ICT can provide the means to support engagement, by helping people to assess the impact and benefits of a CE project and by capturing and disseminating the benefits. Also, ICT can support with the design and management of a CE project; and lastly ICT can support research on the topic.

  10. ICT for Community Energy

    Directory of Open Access Journals (Sweden)

    Caroline Van der Weerdt

    2017-03-01

    Full Text Available Community energy initiatives are becoming more and more widespread. For them to be successful and flourish, engagement from people in the community is a prerequisite. ICT can provide the means to support engagement, by helping people to assess the impact and benefits of a CE project and by capturing and disseminating the benefits. Also, ICT can support with the design and management of a CE project; and lastly ICT can support research on the topic

  11. 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...... 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...

  12. 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.

  13. 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...

  14. Nursing care community health

    Directory of Open Access Journals (Sweden)

    Diana Acosta-Salazar

    2016-07-01

    Full Text Available Process Nursing Care (PAE is a systematic tool that facilitates the scientificity of care in community practice nurse, the application of scientific method in community practice, allows nursing to provide care in logical, systematic and comprehensive reassessing interventions to achieve the proposed results. It began with the valuation of Marjory Gordon Functional Patterns and then at the stage of diagnosis and planning North American Nursing Diagnosis Association (NANDA, Nursing Interventions Classification (NIC and Nursing Outcomes Classification (NOC is interrelate. It is a descriptive and prospective study. Diagnosis was made by applying the instruments measuring scale of the socio-demographic characteristics, symptom questionnaire for early detection of mental disorders in the community and appreciation for functional patterns. The PAE includes more frequent diagnoses, criteria outcomes, indicators, interventions and activities to manage community issues. alteration was evidenced in patterns: Adaptation and Stress Tolerance, Self-perception-Self-concept-, Role-Relationships, sleep and rest and Perception and Health Management. A standardized NANDA-NIC-NOC can provide inter care holistic care from the perspective of community mental health with a degree of scientific nature that frames the professional work projecting the individual, family and community care.

  15. MMI: Increasing Community Collaboration

    Science.gov (United States)

    Galbraith, N. R.; Stocks, K.; Neiswender, C.; Maffei, A.; Bermudez, L.

    2007-12-01

    Building community requires a collaborative environment and guidance to help move members towards a common goal. An effective environment for community collaboration is a workspace that fosters participation and cooperation; effective guidance furthers common understanding and promotes best practices. The Marine Metadata Interoperability (MMI) project has developed a community web site to provide a collaborative environment for scientists, technologists, and data managers from around the world to learn about metadata and exchange ideas. Workshops, demonstration projects, and presentations also provide community-building opportunities for MMI. MMI has developed comprehensive online guides to help users understand and work with metadata standards, ontologies, and other controlled vocabularies. Documents such as "The Importance of Metadata Standards", "Usage vs. Discovery Vocabularies" and "Developing Controlled Vocabularies" guide scientists and data managers through a variety of metadata-related concepts. Members from eight organizations involved in marine science and informatics collaborated on this effort. The MMI web site has moved from Plone to Drupal, two content management systems which provide different opportunities for community-based work. Drupal's "organic groups" feature will be used to provide workspace for future teams tasked with content development, outreach, and other MMI mission-critical work. The new site is designed to enable members to easily create working areas, to build communities dedicated to developing consensus on metadata and other interoperability issues. Controlled-vocabulary-driven menus, integrated mailing-lists, member-based content creation and review tools are facets of the new web site architecture. This move provided the challenge of developing a hierarchical vocabulary to describe the resources presented on the site; consistent and logical tagging of web pages is the basis of Drupal site navigation. The new MMI web site

  16. Women in heterodox communities

    Directory of Open Access Journals (Sweden)

    Posternak Andrei, priest

    2014-02-01

    Full Text Available The author considers women’s ministry in heterodox communities of early Christian time. The author notes that the insufficient of sources (the testimonies of Church historians, apologists, epigraphic stuff and etc did not reveal this problem completely. The article aims to point out some features of heterodox women’s ministry of early Christian time. The author notes women’s activity was emotional. Women in heterodox communities could sufficiently high social status, which might be related to their noble birth or wealth. The heretical communities contained hierarchy of women’s ministries: deaconesses, female priests and the prophetesses leaded the Church community or influenced its life. In heterodox communities women could preach, celebrate Liturgy, baptize, prophecy. Arguments of Christian authors claimed that the women are materially adds through these gifts and led a wicked lifestyle, and they predictions proved false. Radical montanist’s movements formed a new model of women’s behavior breaking late antiquity as well as early Christian view of the woman as a person dependent on men and subordinate to him. Not only a violation of Church’s establishments, but also the independence of women, their desire to preach, as the apostles, and fulfilment of Church sacraments did not fit the public opinion about a woman of that time. The gospel preaching about the ontological men’s and women’s equality in God preceded its time and does not fully fitting into the social situation of the late antiquity.

  17. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    the_monk

    Department of Community Medicine,. Ahmadu Bello University,Zaria. +234 803 705 3845. Email: firstmsibrahim@yahoo.com. Department of Community Medicine, Ahmadu Bello University, Zaria journal of. COMMUNITY MEDICINE. & PRIMARY HEALTH CARE. Journal of Community Medicine and Primary Health Care.

  18. 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...... 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.......Both small and medium-size entrepreneurial firms face liabilities such as resource scarcity and scale diseconomies, making it difficult for them to innovate on a continuous basis. In response, experimentation with new ways of organizing for innovation has increased. One successful result...

  19. 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...

  20. EVALUATING MACROINVERTEBRATE COMMUNITY ...

    Science.gov (United States)

    Since 2010, new construction in California is required to include stormwater detention and infiltration that is designed to capture rainfall from the 85th percentile of storm events in the region, preferably through green infrastructure. This study used recent macroinvertebrate community monitoring data to determine the ecological threshold for percent impervious cover prior to large scale adoption of green infrastructure using Threshold Indicator Taxa Analysis (TITAN). TITAN uses an environmental gradient and biological community data to determine individual taxa change points with respect to changes in taxa abundance and frequency across that gradient. Individual taxa change points are then aggregated to calculate the ecological threshold. This study used impervious cover data from National Land Cover Datasets and macroinvertebrate community data from California Environmental Data Exchange Network and Southern California Coastal Water Research Project. Preliminary TITAN runs for California’s Chaparral region indicated that both increasing and decreasing taxa had ecological thresholds of macroinvertebrates in California streams along

  1. 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.

  2. 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...

  3. Romanian Communities Abroad (II

    Directory of Open Access Journals (Sweden)

    EMILIAN M. DOBRESCU

    2008-03-01

    Full Text Available The number of Romanians living abroad, in Europe, North and South America, Australia and Asia does not excede 11 millions. The biggest Romanian communities are in the United States, Canada, Germany, Australia, France, Italy, Great Britain, Spain, Switzerland, Sweden, Ireland, Venezuela and New Zeeland. If in the case of Romanian ethnics living in the United States, Canada, France, Venezuela etc., we can mainly talk about either pre-war migration or political anticommunist exile, in other states as Italy, Germany, Spain, Ireland or New Zeeland, most of the Romanian communities have been generated by the economic exile, especially after December 1989.

  4. Cyberbullying in your community

    OpenAIRE

    Ingolfsdottir, Anna

    2016-01-01

    Cyberbullying is a continuously developing phenomenon, which can be difficult to measure.Though being a branch of bullying, it is set under new circumstances defined by the newtechnology, internet, and everything else that has come with the new digital age.This technology has made our lives a lot different, and a lot easier, but also poses some challengesin the way we see and conceptualise the world. The question of the absence of physical proximityof a community and how that community is inf...

  5. Community-Engaged Scholarship

    DEFF Research Database (Denmark)

    Barinaga, Ester; Parker, Patricia S.

    2013-01-01

    We are pleased to offer this special issue on community-engaged scholarship. As scholar-activists working for social justice alongside youth of color (Pat) and critical arts activists engaging with stigmatized communities (Ester), we began this project with the intent of gathering a collection...... decolonizing research that exposes and challenges inequalities in the production, outcomes, and sharing of research content. Also, our intent was to collect essays that would highlight the ways scholars are grappling with some of the “prickly” issues (to use the apt term provided by of one of the contributions...

  6. 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’....

  7. Revisiting Matthew's Communities

    Directory of Open Access Journals (Sweden)

    Graham N. Stanton

    1996-12-01

    Full Text Available The article elaborates upon issues raised in the author's 1992 book, 'A 'Gospel for a New People: Studies in Matthew'. These issues concern the relationship of the first recipients of Matthew's gospel to local Jewish communities and the features of the internal life of the communities for which Matthew wrote. In the light of the complexity of reconstructing the social setting of Matthew's gospel, the article aims at locating it in the broadest possible context within early Judaism and  early Christianity.

  8. Intentional communities in Romania. Precursor stage of community integration

    Directory of Open Access Journals (Sweden)

    A. C. MARDACHE

    2017-12-01

    Full Text Available Intentional communities have been present worldwide for many years now, and in Romania they are currently in the formation stage. The present study showcases five such community projects in Romania. By using qualitative research, I have studied the aspects that motivated the members of these communities to be a part of this type of community. The study revealed that the members of intentional communities had different life experiences and internal transformations that made them want to join these communities: health problems, accessing a loan, interests in spirituality, permaculture etc.

  9. The Educating Community.

    Science.gov (United States)

    Ianni, Francis A. J.

    As communities have become increasingly heterogeneous, the congruence between formal education and other socializing institutions has diminished. Nowhere is social discontinuity more visible than in our approach to adolescent education. It is a matter of wide concern that schools are failing to prepare young people for a life of work and social…

  10. communities of rivers, nigeria

    African Journals Online (AJOL)

    DEVELOPMENT EFFORTS OF OIL COMPANIES AS PERCEIVED BY. RURAL HOUSEHOLDS IN SELECTED OIL PRODUCING. COMMUNITIES OF RIVERS, NIGERIA. STATE. MATTHEW UKPONGSON AND DONATUS ONU. ABSTRACT. A total of 120 respondents participated in the study to detemmine the perceptions of ...

  11. Progress in Community Policing

    NARCIS (Netherlands)

    Aronowitz, A.A.

    1997-01-01

    This article examines the development of community-based policing in the United States and the Netherlands. These two countries were selected because the United States has been the forerunner of research into the police and one of the first countries to attempt to introduce on a wide-scale, and

  12. 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,…

  13. Community-Based Care

    Science.gov (United States)

    ... Health A to Z › Community-Based Care Font size A A A Print Share Glossary Basic Facts & Information Other Resources Caregiving How To's Tools & Tips Latest Research Getting More Help Related Topics Assisted Living Home Care Nursing Homes Join our e-newsletter! ...

  14. From Community to Conformity.

    Science.gov (United States)

    Schwartzman, Roy

    Before unconditionally supporting the development of closer community or the restoration of a public realm, communication scholars should further reflect on the historical uses and potential threats attendant to this task. A sense of nostalgia sometimes romanticizes the Greek "polis" while sidestepping the changes wrought by population…

  15. 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…

  16. Reconstructing Community History

    Science.gov (United States)

    Shields, Amy

    2004-01-01

    History is alive and well in Lebanon, Missouri. Students in this small town in the southwest region of the state went above and beyond the community's expectations on this special project. This article describes this historical journey which began when students in a summer mural class reconstructed a mural that was originally created by a…

  17. Partners of the Community.

    Science.gov (United States)

    Reese, Susan

    2002-01-01

    Oklahoma has a long tradition of partnering with the community and its career-tech system is viewed as the economic development arm of the Oklahoma Public School system. A partnership between the Tri County Technology Center and University of Oklahoma, for example, involves dental hygiene students in providing oral health care for poor rural…

  18. Rural Communities: Legacy & Change.

    Science.gov (United States)

    Flora, Cornelia Butler; And Others

    This book is designed to help identify, analyze, and address problems that are found in rural parts of the United States. It focuses on the community as the place where individuals come together in order to solve those problems. The book's 13 chapters are divided into 4 sections. The first section discusses rural definition and community…

  19. Families and Communities (Bookalogues).

    Science.gov (United States)

    Martinez, Miriam; Nash, Marcia F.

    1993-01-01

    Presents brief reviews of 26 picture books, chapter books, and informational books that deal with families and/or communities. Notes that the picture books and chapter books cover a wide variety of genres including poetry, realistic fiction, and fantasy and that the informational books have a variety of formats, with the "photo essay" dominating.…

  20. Violence and Community Capabilities:

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

    This Working Paper was prepared by the Latin American Faculty of Social. Sciences (FLACSO) and .... America, synthesizing data from across the region and highlighting trends and consequences. The second ..... destabilize the situation in order to safeguard their economic and social influence in these communities.

  1. Professional Learning Communities

    Science.gov (United States)

    Eley, Alison

    2017-01-01

    There are many professional development programmes on offer for primary science. The best of these involve teachers in developing practice over time, alongside engaging with theory. In this article, the author considers how working as part of a professional learning community can support a collaborative and evidence informed approach to improving…

  2. COMMUNITY BASED REHABILITATION

    African Journals Online (AJOL)

    PROF. OLAOGUN

    Department of Physiotherapy, School of Allied Health Sciences, College of Health Sciences, University of Ghana. Correspondence. Matthew ... and technology to developing countries was facilitated by the United Nations Organization (UNO). The results, .... impact of interventions are also part of community health practice.

  3. Engaging Our Community Colleges

    Science.gov (United States)

    Meyer, Darrel W.

    2011-01-01

    The United States and Canada have a long tradition in recognizing that there are considerable social and economic benefits of providing high quality education to as many people as possible. Community colleges made a significant contribution in expanding educational opportunities for the masses. Attendance at one of these institutions is associated…

  4. 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…

  5. 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…

  6. 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...

  7. 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.)

  8. [Reinvesting in Black Communities].

    Science.gov (United States)

    Shipp, James

    Some of the issues involved in promoting home ownership among blacks and investment in inner city communities are discussed in this paper. The experiences of the Bedford Stuyvesant Restoration Corporation in revitalizing Bedford Stuyvesant are described. Economic barriers to prospective home ownership are identified and strategies and programs…

  9. Community Antenna Television (CATV).

    Science.gov (United States)

    Federal Communications Commission, Washington, DC.

    The number of households hooked up to cable television or community antenna television (CATV) is expanding rapidly, and Federal Communications Commission (FCC) has been developing regulations since 1962 to guide the growth of the industry. By 1965 the FCC had claimed jurisdiction over all CATV systems in the U. S. This jurisdiction was challenged…

  10. Online Community Transition Detection

    DEFF Research Database (Denmark)

    Tan, Biying; Zhu, Feida; Qu, Qiang

    2014-01-01

    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...

  11. 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…

  12. 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

  13. 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)

  14. 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

  15. Hlatlolanang: a community project.

    Science.gov (United States)

    Stober, P

    1993-01-01

    Sekekhuneland, which is in the northern Transvaal in South Africa, has suffered from a 2-year drought which has led to a shortage of basic food in the villages and a 50-60% incidence of kwashiorkor among the village children. The natural resources of the area have been eliminated by over population and its attendant deforestation, land erosion, and wildlife decimation. The situation has been exacerbated by a political climate rife with corruption and incompetence. The most pressing problem is a shortage of water which prevents agricultural development and limits food production. Some dangerous traditional beliefs persist, such as believing that sickness is caused by curses which modern medicine cannot affect. In response to this situation, Hlatlolanang ("we share the burden"), a community-based development program has been put into place. The director of the center, Rose Mazibuko, is a nurse who believes that primary health care in its broadest sense is a human right. This involves not only the health sector but also agriculture, industrial development, education, housing, and public works. The first problem tackled was kwashiorkor. Other groups had failed to reduce the incidence of the condition in the area. Hlatlolanang recognized that mothers of affected children were being stigmatized by hospital personnel. Thus, the mothers would often go to the hospital only as a last resort and would avoid the training necessary to help their children. The community requested that Hlatlolanang become a training center where all members of the community could learn how to combat kwashiorkor and where inappropriate attitudes could undergo the necessary changes. Thus, the Hlatlolanang Health and Education Center was born with funding from the Kaiser Family Foundation, an architect who participated in the development workshop and knew exactly what the community wanted, an elected planning committee, and 4 local builders. People were carefully screened and hired to run the center

  16. 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

  17. Putting the Community Back into Community Networks: A Content Analysis

    Science.gov (United States)

    Horning, Michael A.

    2007-01-01

    This study examines the role that community networks can take in fulfilling McQuail's call for a more democratic-participant form of mass media. Community networks, which are online grassroots organizations designed to promote local community initiatives, increased their Internet presence in the 1990s. However, their number has declined in recent…

  18. Examining Electronic Learning Communities through the Communities of Practice Framework

    Science.gov (United States)

    Linton, Jayme N.

    2015-01-01

    This qualitative interpretive case study used Wenger's (1998) communities of practice (CoP) framework to analyze how the electronic learning community (eLC) process at an established state virtual high school operated like a community of practice. Components of the eLC process were analyzed according to elements of the CoP framework, which…

  19. 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.

  20. Just a Community Organizer: Community/Campus Connections through Organizing

    Science.gov (United States)

    Liu, Judith; Kelly, Donald P.

    2010-01-01

    The 2008 presidential election catapulted "community organizers" into the media fray and raised awareness about community organizing. At the University of San Diego (USD), a course teaching consensus organizing techniques to address community issues was instituted in 2004. The course incorporates traditional undergraduate students and…

  1. Community psychiatry's achievements.

    Science.gov (United States)

    Burns, T

    2014-12-01

    Mental health care in the second half of the 20th century in much of the developed world has been dominated by the move out from large asylums. Both in response to this move and to make it possible, a pattern of care has evolved which is most commonly referred to as 'Community Psychiatry'. This narrative review describes this process, from local experimentation into the current era of evidence-based mental health care. It focuses on three main areas of this development: (i) the reprovision of care for those discharged during deinstitutionalisation; (ii) the evolution and evaluation of its characteristic feature the Community Mental Health Team; and (iii) the increasing sophistication of psychosocial interventions developed to support patients. It finishes with an overview of some current challenges.

  2. IT User Community Survey

    CERN Multimedia

    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.

  3. Romanian communities abroad

    Directory of Open Access Journals (Sweden)

    Emilian M. Dobrescu

    2008-02-01

    Full Text Available The number of Romanians living abroad, in Europe, North and South Ame­rica, Australia and Asia does not exceed 11 million. The biggest Romanian communities are in the United States, Canada, Germany, Aus­tralia, France, Italy, Great Britain, Spain, Switzerland, Sweden, Irelan­d, Venezuela and New Zealand. If in case of Romanian ethnics living in the United States, Canada, France, Vene­zu­ela, etc., we can mainly talk about either pre-war migration or anticommunist political exile, in other states such as Italy, Ger­ma­ny, Spain, Ireland or New Zea­­land, most of the Romanian communities have been generated by the economic exile, especially after December 1989.

  4. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    com. +234 803 5837179. KEYWORDS. Disease surveillance, notification, resident doctors,. Edo State journal of. COMMUNITY HEALTH. & PRIMARY HEALTH CARE. Journal of Community Medicine and Primary Health Care. 26(2) 107-115 ...

  5. 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)

  6. 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,

  7. Design Democratization with Communities

    DEFF Research Database (Denmark)

    Winschiers-Goagoses, Naska; Winschiers-Theophilus, Heike; Rodil, Kasper

    2012-01-01

    The authors present community drawing as meaningful representations to inform locally valid technology design. They investigate recognition within and across cultural borders, thereby exposing variances of localities. The study contributes to the still scarce body of empirical work on culturally ...... meaningful development of visual representations and recognition, as part of a longitudinal research project in which we co-design a 3D visualization for a specific Namibian pilot site....

  8. Discourses of Community

    DEFF Research Database (Denmark)

    Sevelsted, Anders

    on civil society through ‘colonization’, while civil society organizations act as ‘sensors’ for experiences of marginalization. Based on a case study of the discursive and political relations between the temperance organization The Blue Cross and the Danish state 1900-1938, this article shows empirically...... by discourses emphasizing community over the individual. Some implications, including increased sensitivity to social relations, culture, and experience, for theories on civil society/state relations are hinted at....

  9. Reconceptualising dementia friendly communities

    OpenAIRE

    Wright, T.

    2014-01-01

    This Knowledgeshare piece takes a critical look at the concept of dementia-friendly communities by examining how that concept, which aims to build a better place for people with dementia to live, works to conceal and overlook the social, cultural, political, and economic realities of many marginalised people’s lived experiences. Drawing on knowledge from feminist social cultural theories I want to highlight some of the undisclosed subjectivities that are hidden in representations of people li...

  10. 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

  11. 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

  12. 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

  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. 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…

  15. Detecting communities through network data

    NARCIS (Netherlands)

    Bruggeman, J.; Traag, V.A.; Uitermark, J.

    2012-01-01

    Social life coalesces into communities through cooperation and conflict. As a case in point, Shwed and Bearman (2010) studied consensus and contention in scientific communities. They used a sophisticated modularity method to detect communities on the basis of scientific citations, which they then

  16. 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 organization ... As part of her corporate social responsibility. Shell in collaboration ... As a result, communities lost faith in the concept provided before the introduction of the CHIS. For of PHC which ...

  17. 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…

  18. 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.

  19. 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.

  20. The Community of Rights

    DEFF Research Database (Denmark)

    Kjærgård, Jonas Ross

    2012-01-01

    The article presents the argument that in order to have human rights in the years of the French Revolution it was necessary to be and act in accordance with an ambiguous concept of the natural. While the idea of the natural or of human nature could be an inclusive and universal one, it could also...... 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...

  1. Urban Climate Risk Communities

    DEFF Research Database (Denmark)

    Blok, Anders

    2016-01-01

    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...... 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...

  2. 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...

  3. 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)

  4. 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.

  5. Free-Religious Communities

    Directory of Open Access Journals (Sweden)

    E. KOROSTICHENKO

    2015-06-01

    Full Text Available This paper presents a study on history of spiritual and practical activities of so-called free-religious communities (freireligiösen Gemeinden created in 1840s in Germany by «the German Catholics» and Protestant «friends of light» — originally separate movements, opposite to Catholic and Protestant orthodoxy respectively. The analysis presents a complete picture of development of the free-religious movement, starting from its emergence during the Vormärz period. The span of research covers intense activity during the revolution of 1848–1849, the period of political reaction following soon after the suppression of revolution, the ultimate ban by national-socialists in fascist Germany, reaching up to our days. Additionally, focus is given to the preceding tradition of the German free-thinking and its connection with the free-religious movement. It is shown that one of the distinctive features of the free-religious movement is the variety of world-view among ideologists of its different communities. Thus, this movement falls under a special category, intermediate between religion and secular outlook. As a result of the analysis the author comes to a conclusion that the ideology of the free-religious movement can be characterized by interweaving of religious and political motives in its program, and the deviation that the views of its adherents take from orthodox Christianity — to pantheism and even materialism.

  6. 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.

  7. 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.

  8. Sense of Community in a Context of Community Violence.

    Science.gov (United States)

    Távara, María Gabriela; Cueto, Rosa María

    2015-01-01

    The following study analyzes the concept of sense of community of a group of people living in a shanty town in a district in the eastern outskirts of Lima, characterized by processes of community violence. With this in mind, a mixed methodology and a concurrent design were chosen, applying the Scale of Sense of Community, SCI-2, a question to measure the perceived level of danger through a Likert scale, and five individual interviews with the population. The results show that the higher the level of danger perceived in the zone, the lower the sense of community is. Likewise, in this group of people their sense of community is based above all on an emotional shared connection and on a strong feeling of membership. On the contrary, the difficulty to satisfy their collective needs through organization and the weak relationship that exists between the population and its leaders, decrease and deteriorate the sense of community in this group.

  9. Bounded Community: Designing and facilitating learning communities in formal courses

    Directory of Open Access Journals (Sweden)

    Brent G. Wilson

    2004-11-01

    Full Text Available Learning communities can emerge spontaneously when people find common learning goals and pursue projects and tasks together in pursuit of those goals. Bounded learning communities (BLCs are groups that form within a structured teaching or training setting, typically a course. Unlike spontaneous communities, BLCs develop in direct response to guidance provided by an instructor, supported by a cumulative resource base. This article presents strategies that help learning communities develop within bounded frameworks, particularly online environments. Seven distinguishing features of learning communities are presented. When developing supports for BLCs, teachers should consider their developmental arc, from initial acquaintance and trust-building, through project work and skill development, and concluding with wind-down and dissolution of the community. Teachers contribute to BLCs by establishing a sense of teaching presence, including an atmosphere of trust and reciprocal concern. The article concludes with a discussion of assessment issues and the need for continuing research.

  10. 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

  11. Epilithic and endolithic microorganisms and deterioration on stone church facades subject to urban pollution in a sub-tropical climate.

    Science.gov (United States)

    Gaylarde, Christine; Baptista-Neto, Jose Antônio; Ogawa, Akiko; Kowalski, Matthew; Celikkol-Aydin, Sukriye; Beech, Iwona

    2017-02-01

    Weathering of two church facades in Rio de Janeiro was caused substantially by salts, mainly halite and gypsum, detected by SEM and chemical analyses, which cause physical stresses by deposition within the rock. Biofilm populations, determined by SEM and as operational taxonomic units (OTUs), degraded stone by penetration, solubilization and redeposition of minerals on their surfaces. Endolithic cyanobacteria were associated with gypsum deposits. Microbiomes were typical for high-stress environments, high salt, intense insolation, low water and low nutrients (eg halophilic Rubrobacter, Salinicola, Sterigmatomyces). The main colonizers on the church most affected by traffic (Nossa Senhora da Candelária - CA) were Actinobacteria; Gammaproteobacteria (chiefly Pseudomonas) were predominant on the site situated in a leafy square (São Francisco de Paula - SF). Major Gammaproteobacteria on CA were halophilic Halomonas and Rhodobacteriaceae. Fungal OTUs on both churches were principally dimorphic, yeast-like basidiomycetes. Many OTUs of thermophilic microorganisms (eg the Thermomicrobia class, Chloroflexi) were present. This is the first use of next generation sequencing (NGS) to study microbial biofilm interactions with metamorphic and granite buildings in an intensely urban, sub-tropical climate.

  12. Depth distribution of epilithic cyanobacteria and pigments in a mountain lake characterized by marked water-level fluctuations

    Czech Academy of Sciences Publication Activity Database

    Cantonati, M.; Guella, G.; Komárek, Jiří; Spitale, D.

    2014-01-01

    Roč. 33, č. 2 (2014), 537-547 ISSN 2161-9549 Institutional support: RVO:67985939 Keywords : epilithon * cyanobacteria * depth distribution Subject RIV: EF - Botanics Impact factor: 1.941, year: 2014

  13. Epilithic and aerophilic diatoms in the artificial environment of Kungsträdgården metro station, Stockholm, Sweden

    DEFF Research Database (Denmark)

    Norbäck Ivarsson, Lena; Magnus, Ivarsson; Lundberg, Johannes

    2013-01-01

    The Kungsträdgården metro station is an artificial and urban subsurface environment illuminated with artificial light. Its ecosystem is almost completely unknown and as a first step to better understand the biology and rock wall habitats the diatom flora was investigated. A total of 12 species were...... found growing on the rock walls of Kungsträdgården metro station. The results show the diatom flora in Kungsträdgården to be dominated by e.g. Diadesmis contenta, Diadesmis perpusilla, Pinnularia appendiculata, Nitzschia amphibia, Nitzschia sinuata and Diploneis ovalis. One species, Caloneis cf...

  14. 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...

  15. 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

  16. Inoculation history affects community composition in experimental freshwater bacterioplankton communities.

    Science.gov (United States)

    Rummens, Koen; De Meester, Luc; Souffreau, Caroline

    2018-03-01

    Priority effects occur when the arrival order of species or genotypes has a lasting effect on community or population structure. For freshwater bacteria, priority effects have been shown experimentally among individual species, but no experiments have been performed using complex natural communities. We investigated experimentally whether a foreign bacterioplankton community influences the community assembly trajectory when inoculated prior to the local community, whether inoculation time lag affects priority effects, and how the individual OTUs responded to time lag. Two bacterioplankton communities from dissimilar ponds were inoculated into one of the natural media with a time lag of 0, 12, 36 or 60 h, giving advantage in time to the foreign community. All three time lags resulted in priority effects, as the final community composition of these treatments differed significantly from that of the treatment with no time lag, but compositional shifts were not linear to inoculation time lag. The responses of individual OTUs to time lag were highly diverse and not predictable based on their immigration history or relative abundance in the inocula or control. The observed impact and complexity of priority effects in multispecies systems emphasize the importance of this process in structuring both natural and industrial bacterial communities. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. 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.

  18. Community photosynthesis of aquatic macrophytes

    DEFF Research Database (Denmark)

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

    2006-01-01

    light use efficiency at low irradiance (a) was the same. Although GPmax and a varied extensively among the 190 communities, their upper limits increased linearly and predictably with community absorption reaching 26.3 mmol m22 s21 O2 and 0.090 mol mol21 photon at 100% absorption. The upper limit...... fourfold from communities with a very uneven to a more even light distribution. Photosynthetic characteristics of communities are strongly influenced by plant density, absorption, and distribution of light and cannot be interpreted from the photosynthetic behavior of phytoelements. Thus, many examples......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...

  19. 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

  20. 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.

  1. 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

  2. Resizing Auditory Communities

    DEFF Research Database (Denmark)

    Kreutzfeldt, Jacob

    2012-01-01

    Heard through the ears of the Canadian composer and music teacher R. Murray Schafer the ideal auditory community had the shape of a village. Schafer’s work with the World Soundscape Project in the 70s represent an attempt to interpret contemporary environments through musical and auditory...... musicalized through electro acoustic equipment installed in shops, shopping streets, transit areas etc. Urban noise no longer acts only as disturbance, but also structure and shape the places and spaces in which urban life enfold. Based on research done in Japanese shopping streets and in Copenhagen the paper...... presents some terminologies for mapping urban environments through its sonic configuration. Such probing into the practices of acoustic territorialisation may direct attention to some of the conflicting and disharmonious interests defining public inclusive domains. The paper investigates the concept...

  3. Resizing Auditory Communities

    DEFF Research Database (Denmark)

    Kreutzfeldt, Jacob

    2012-01-01

    Heard through the ears of the Canadian composer and music teacher R. Murray Schafer the ideal auditory community had the shape of a village. Schafer’s work with the World Soundscape Project in the 70s represent an attempt to interpret contemporary environments through musical and auditory...... parameters highlighting harmonious and balanced qualities while criticizing the noisy and cacophonous qualities of modern urban settings. This paper present a reaffirmation of Schafer’s central methodological claim: that environments can be analyzed through their sound, but offers considerations on the role...... musicalized through electro acoustic equipment installed in shops, shopping streets, transit areas etc. Urban noise no longer acts only as disturbance, but also structure and shape the places and spaces in which urban life enfold. Based on research done in Japanese shopping streets and in Copenhagen the paper...

  4. 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....

  5. 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

  6. Metacommunication patterns in online communities

    OpenAIRE

    Lanamäki, Arto; Päivärinta, Tero

    2009-01-01

    Published version of a chapter in the book: Online Communities and Social Computing. Also available from the publisher at http://dx.doi.org/10.1007/978-3-642-02774-1_26 This paper discusses about contemporary literature on computer-mediated metacommunication and observes the phenomenon in two online communities. The results contribute by identifying six general-level patterns of how metacommunication refers to primary communication in online communities. A task-oriented, user-administrated...

  7. 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 ...

  8. 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 relat...... with an experimental vignette study of the effects of clan and kinship ties on recruitment and selection decisions in Kazakhstan, followed by qualitative interviews....

  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. Emergence in pelagic communities

    Directory of Open Access Journals (Sweden)

    C. S. Reynolds

    2001-12-01

    Full Text Available Pelagic systems, those based on the open waters of large lakes and seas, provide excellent opportunities for ecological study. This is because, the vastness of the oceans apart, pelagic ecosystems operate on short space and time scales. This affords important opportunities to study the emergence of ecosystems and the basis of striking high-order patterns of ecosystem behaviour. The essay seeks an outline of the processes by which the biologies of individual organisms - the largest functional, controlled units in the ecosystem - interact and bias the outcomes in favour of particular network structures recognised by ecologists. Populations build, communities assemble, ecosystems function but always in ways that relate to the match between the adaptations and performances of individual species and the capacities of the environments in which they find themselves. The paper attempts to discern the linkages between the biology of individual and the ways that ecosystems are put together, between organisms and organisation. Drawing on the advantages of absolutely short generation times among the producers, consumers and heterotrophs of the pelagic, I seek to sample the ascendant pathways of ecosystem synthesis, noting the energetic decisions which select for particular outcomes. However, the simple organisational state of many pelagic communities reminds us that ascendancy is frequently restrained by a scarcity of resources and tempered by the frequent intervention of abiotic factors. The presentation does not seek to prove any point about systems: it attempts to re-affirm what is known about organisational hierarchies; then, using approximate quantities, the points of bifurcation between alternative organisational structures are nominated; drawing upon suppositions about the dissipation of energy, the organisational underpinning of function at the level of the whole ecosystem is proposed. Corroboration from observations from the real world is sought

  11. 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...

  12. 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.

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

    African Journals Online (AJOL)

    ... ¡°top-down¡± to ¡°bottom-up¡± development efforts in the country with a view to reducing poverty and developmental imbalance in Nigeria. Content analysis of the data collected showed that the community-based organisations in the study areas and Community-Based Poverty Reduction Programme (CPRP) in Abia State, ...

  14. Asian Americans in Community Colleges: UCLA Community College Bibliography

    Science.gov (United States)

    Liu, Amy

    2007-01-01

    The references presented in this bibliography provide an overview of recent scholarship on Asian Americans in community colleges. Included in this bibliography are educational reports, case studies, literature reviews, and analyses that reflect upon the experience of Asian Americans in community colleges. The references also address the barriers…

  15. 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.

  16. Community of Inquiry Framework: Establishing Community in an Online Course

    Science.gov (United States)

    Lambert, Judy L.; Fisher, Juenethia L.

    2013-01-01

    Using the Community of Inquiry (CoI) framework, the author conducted a mixed method research study to examine the existence of the three CoI elements in a graduate-level educational technology online course. The author also looked at student perceptions and preference for community in online learning. High mean scores on the CoI showed that all…

  17. 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 ...

  18. Enhancing Community Service Learning via Practical Learning Communities

    Science.gov (United States)

    Ronen, Ilana; Shemer-Elkiyam, Tal

    2015-01-01

    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…

  19. Diversity, Community, and Pluralism in Jewish Community Day High Schools

    Science.gov (United States)

    Kress, Jeffrey S.

    2016-01-01

    Students in "community" (nondenominational) Jewish high schools represent a diversity of denominational affiliations, including those who affiliate with more than one denomination and those that affiliate with none. These schools strive to create communities in which students with varying Jewish beliefs and practices are, at the very…

  20. Cultural Prospects for an East Asian Community (Community)

    OpenAIRE

    Hirano, Kenichiro

    2010-01-01

     Today, people discuss whether it is possible to have a regional community in East Asia like the one in Europe. Many people desire one for East Asia, but tend to think it is difficult for Asia, far more difficult than for Europe. However, I believe it is possible to declare that an East Asian Community is being created now.

  1. 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

  2. Knowledge sharing in knowledge communities

    NARCIS (Netherlands)

    Hooff, B. van den; Elving, W.; Meeuwsen, J.M.; Dumoulin, C.

    2003-01-01

    In this chapter of the book ‘Communities and Technologies’ (M. Huysman et al. (eds.), Kluwer 2003) the contribution of ICT to knowledge sharing in communities of practice is investigated. A theoretical model is built that identifies the possible influence of ICT on the extent to which knowledge is

  3. Community Hospital Telehealth Consortium (CHTC)

    Science.gov (United States)

    2003-12-30

    technology to improve and expand the opportunity for rural and urban underserved populations to receive quality, affordable health care....The Community Hospital Telehealth Consortium (CHTC) is a unique, forward-thinking, community-based healthcare service project organized around 6 not

  4. Local community, mobility and belonging

    DEFF Research Database (Denmark)

    Jørgensen, Anja; Arp Fallov, Mia; Knudsen, Lisbeth B.

    2011-01-01

    The purpose of this article is to pose some theoretical questions to the relations between local community, mobility and belonging.In continuation the methodological implications of the theoretical debate are discussed.The article also outlines different perspectives on local neighbourhoods,recen...... the classic Chicago school of sociology can create a productive approach to the study of local community, mobility and belonging....

  5. Union Members Are Community Members

    Science.gov (United States)

    Gray, David

    2013-01-01

    Unions serve their members' interests. But union members are also community members, and their interests go well beyond increasing pay and benefits. A local union president has found that his members are best served by participating in a community-wide coalition. Providing eyeglasses to needy students, promoting healthy eating, and increasing…

  6. Simple Machines in the Community

    Science.gov (United States)

    Bryan, Robert; Laroder, Aris; Tippins, Deborah; Emaz, Meliza; Fox, Ryan

    2008-01-01

    The community can be a powerful context and mini-laboratory for cultivating students' common understandings of science and mathematics. On the island of Panay in the Philippines, the community was the starting place for a group of fifth- and sixth-grade students to explore simple machines in their daily lives. What students learned in the process…

  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. 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 ...

  9. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    ajiboro

    1,2. Organization, the community health worker was health system when the country adopted the PHC introduced into the health system for various strategy to achieve the goal of health for all. 76. JOURNAL OF COMMUNITY MEDICINE AND PRIMARY HEALTH CARE VOL. 25, NO 2, SEPTEMBER 2013. Correspondence to.

  10. 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

  11. 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.…

  12. Ethics in contemporary community psychiatry.

    Science.gov (United States)

    Everett, Anita; Huffine, Charles

    2009-06-01

    Community psychiatry is a wonderful and rewarding career path that increasing numbers of psychiatrists are choosing to practice.14 This article was created to provide an orientation to the characteristics of contemporary community psychiatric practice that render it distinct in terms of ethical considerations. We defined and described community practice. We provided a framework based on classical medical ethics that can be used to consider challenges in particular community practice situations. We also offered special considerations of key areas in which community practice demands novel treatment methods coupled with special clinical expertise in assessing risks and benefits. We hope to have provided a discussion that supports a broadening of existing psychiatric ethical guidelines so that they are inclusive of the kinds of situations routinely encountered by community psychiatrists and other community mental health care professionals and paraprofessionals. It is our hope that ideas presented in this article will help to equip psychiatrists and their community teams to facilitate the successful rehabilitation and recovery of the individuals they serve.

  13. 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…

  14. The Charm of Community Music

    Science.gov (United States)

    Ruisen, Xu

    2011-01-01

    Music education in communities is a newly sprouted thing and is gradually catching people's attention. Music education seeks to promote community members' aesthetic senses. Music and the arts, the best tools for moving people's souls, link different hearts across various boundaries, affecting all aspects of social life. Music education can serve…

  15. Leadership in Professional Learning Communities

    Science.gov (United States)

    Thornton, Kate; Cherrington, Sue

    2014-01-01

    Professional learning communities in the early childhood education sector have been under-researched. The focus on collaborative learning, collective enquiry and shared leadership of such communities makes them worthy of study in order to establish their relevance to the sector. One of the foci of this research involving case studies of different…

  16. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    CHILDREN,. SCHOOL HEALTH. Correspondence to. Dr Kofoworola A Odeyemi. Department of Community Health, University of Lagos . Lagos. Nigeria. Email kofoodeyemi@yahoo.com. Journal of Community Medicine and Primary Health Care. 25 (1) 51-57. Background: Visual impairment is usually due to conditions that ...

  17. 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

  18. 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

  19. 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.

  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. 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…

  2. 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

  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. Reviving the Mediterranean Olive Community

    Science.gov (United States)

    Zaferatos, Nicholas C.

    2011-01-01

    This article presents the findings of a collaborative investigation by six nongovernment organisations (NGOs) from five European-Mediterranean countries to identify a framework for reversing rural marginalisation in Mediterranean communities through sustainable forms of community-based agricultural development. The project brought together…

  5. 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: ...

  6. Profiting from innovative user communities

    DEFF Research Database (Denmark)

    Jeppesen, Lars Bo

    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......, 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...

  7. 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....

  8. 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.

  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 mothers' programme: extension to the travelling community in Ireland.

    Science.gov (United States)

    Fitzpatrick, P; Molloy, B; Johnson, Z

    1997-06-01

    To see whether the community mothers' programme, using lay volunteer mothers to deliver a childhood development programme, could be extended successfully to the travelling community in Ireland. This was a prospective study of the travelling community; comparisons were made with results of a previous randomised trial of settled mothers. A regional health authority in Ireland. These comprised 39 traveller and 127 settled intervention mother/ infant pairs (randomised controlled trial (RCT) intervention); settled community mothers; 105 settled control pairs (RCT control). All mothers received standard support; traveller and RCT intervention groups also received the services of a community mother. The travellers' sociodemographic profile differed significantly from the other groups. At the end of the study, traveller and intervention children were exposed to more cognitive games and nursery rhymes. There were significant differences in the proportions who received all three shots of their primary immunisation schedule before 12 months of age and who received "three in one" vaccination, with traveller children doing least well. The diet of traveller children surpassed that of RCT controls in all food groups except fruit; they were less likely to begin cows' milk before 26 weeks of age. Traveller mothers' diet was superior to that of RCT control and similar to RCT intervention mothers. Traveller and RCT intervention mothers were less likely to feel tired, feel miserable, and want to stay indoors than RCT control mothers. The results of the community mothers' programme in the travelling community are encouraging; poor immunisation uptake remains a challenge.

  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. [Development of model communities (Cool Communities)]. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This report covers progress in the Cool Communities program and is intended to detail specific accomplishments during the year and to provide a limited amount of background information about the program and its progress over the past three years. The Cool Communities project is driven by local partnerships among business, citizens, government, and guided by a Local Advisory Committee of representatives from these organizations. A national overview of the program is given in the first section. The second section describes specific accomplishments in each of the model communities in Dade County, Atlanta, Frederick, Tucson, Springfield, Austin, and the Davis Monthan Air Force Base.

  13. 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

  14. Gay men and ambivalence about 'gay community': from gay community attachment to personal communities.

    Science.gov (United States)

    Holt, Martin

    2011-09-01

    The concept of 'gay community', and gay men's attachment to and involvement in gay community activities, has held both a symbolic and practical role in understanding and guiding responses to HIV in developed world contexts. In the West, the HIV epidemic has disproportionately affected gay men. Being involved in and connected to gay community activities (what, in Australia, is described as 'gay community attachment') predicted the adoption of safe sex practices. However, the meaning of gay community is changing. This presents a challenge to those working in HIV prevention. With reference to previous research, the meaning of gay community is analysed in qualitative interviews conducted with Australian gay men. The interview data indicate that gay men are often ambivalent about gay communities, suggesting a need for subtlety in the ways we think about and address gay men in HIV education and health promotion. The concept of 'personal communities' may better reflect the ways in which gay men engage with each other and their social networks. Recognising and responding to the changing nature of gay life will ensure that the flexibility and pragmatism of HIV programmes aimed at gay men are maintained.

  15. Using Community Mapping in Human Ecology

    Science.gov (United States)

    Robinson, Chery M.; Vineyard, Michelle L.; Reagor, Jane D.

    2004-01-01

    Community asset mapping is one approach to community assessment. According to Kretzmann and McKnight (1993), discovering the assets, capacities, and resources embedded in a community leads people to take responsibility for and ownership of rebuilding and renewing their community. Community mapping is a tool for consideration by family and consumer…

  16. Community Media: Muting the Democratic Media Discourse?

    NARCIS (Netherlands)

    Carpentier, N.; Lie, R.; Servaes, J.

    2003-01-01

    Focuses on the concept of community media. Components that construct the identity of community media; Multi-theoretical approaches for analysis of community media; Definition of community media based on the concept of alternative media; Link between community media and civil society; Problems faced

  17. Community-acquired pneumonia.

    Science.gov (United States)

    Cassiere, H A; Niederman, M S

    1998-11-01

    Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality in all age groups, especially the elderly, which is a patient population that continues to grow. Recently the spectrum and clinical picture of pneumonia has been changing as a reflection of this aging population; this requires a reassessment of and a new approach to the patient with pneumonia. Currently, pneumonia patients are classified as having either community-acquired or hospital-acquired infection rather than typical versus atypical. Patients who have CAP are categorized by age, presence of a coexisting medical illness, and the severity of the pneumonia. The rationale behind categorizing patients is to stratify them in terms of mortality risk to help determine the location of therapy (e.g., outpatient, inpatient, intensive care unit) and focus the choice of initial antimicrobial therapy. Once the decision to hospitalize a patient with pneumonia is made, the next step is to decide on an appropriate diagnostic evaluation and antibiotic therapy. Both decisions have evolved over the last several years since the publication of the American Thoracic Society's CAP guidelines. The current approach to the diagnostic work-up of pneumonia stresses a limited role of diagnostic tests and procedures. The antimicrobial regimen has now evolved into one that is empiric in nature and based on the age of the patient, the presence of coexisting medical disease, and the overall severity of the pneumonia. This process is a dynamic once because bacterial resistance to commonly used antibiotics can further complicate the course of pneumonia therapy, but the impact of resistance on outcome is less clear. Resistance of Streptococcus pneumoniae to penicillin is a prime example of this growing problem, and adjustment to pneumonia therapy may be required. A difficult but not uncommon problem in pneumonia patients is slow recovery and delayed resolution of radiographic infiltrates. Factors that impact

  18. Creative communities, creative assets: exploring methods of mapping community assets

    OpenAIRE

    Greene, Catherine; Alevizou, Giota; Ramster, Gail; Alexiou, Katerina; Zamenopoulos, Theo; Outten, Alan; Corzannelli, Cristina

    2013-01-01

    Asset mapping, a method for unearthing and visually representing an individual’s or a community's assets, has been used in the context of planning and creative industries. The goal of this workshop is to bring together stakeholders from diverse backgrounds and practices to discuss and generate outcomes that make use of different perspectives of asset mapping methodologies. At the core of activities, facilitators will demonstrate the ways in which asset mapping has been used with community gro...

  19. Community Participation Tourism Management Model of Tapee Plain Community

    OpenAIRE

    W. Srisuwan; S. Chantachan; P. Thidpad

    2011-01-01

    Problem statement: Cultural tourism plays an important role in the economy system of Thailand. This study, therefore, aims to investigate the following: (1) The tourism conditions in the community of Taa-Pee River Basin and also; (2) The possible guideline of organizing the cultural tourism, by all means, seeking active cooperation among the Taa-Pee River Basin community people who subsist or have been subject to the river basin and the surrounding conditions. Approach: Th...

  20. Technology, Empowerment and Community Radio

    OpenAIRE

    Salvatore Scifo

    2015-01-01

    This article will provide an overview of the conceptual contours of community media and community radio, highlighting some of the key questions shaping the debate and, with the help of a case study, show how digital media in the context of community radio can help local groups to get a voice in their local media systems, and how a university-based radio station, and its students and volunteers, play an important role for a more diverse and vibrant media content available in their area.

  1. 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.

  2. 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.

  3. 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...

  4. Community Health Workers Support Community-based Participatory Research Ethics:

    Science.gov (United States)

    Smith, Selina A.; Blumenthal, Daniel S.

    2013-01-01

    Ethical principles of community-based participatory research (CBPR)— specifically, community engagement, mutual learning, action-reflection, and commitment to sustainability—stem from the work of Kurt Lewin and Paulo Freire. These are particularly relevant in cancer disparities research because vulnerable populations are often construed to be powerless, supposedly benefiting from programs over which they have no control. The long history of exploiting minority individuals and communities for research purposes (the U.S. Public Health Service Tuskegee Syphilis Study being the most notorious) has left a legacy of mistrust of research and researchers. The purpose of this article is to examine experiences and lessons learned from community health workers (CHWs) in the 10-year translation of an educational intervention in the research-to-practice-to-community continuum. We conclude that the central role played by CHWs enabled the community to gain some degree of control over the intervention and its delivery, thus operationalizing the ethical principles of CBPR. PMID:23124502

  5. Mobility monitoring in your community : interactive workshop.

    Science.gov (United States)

    2010-01-01

    For Lesson 4 interactive exercise, participants choose from one of three different maps to identify the : needs and opportunities based on community input. The three maps are medium-sized community, small : community with relief route, and smal...

  6. 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)

  7. The Founding of the Learning Communities Association

    Science.gov (United States)

    Huerta, Juan Carlos

    2017-01-01

    Learning communities have reached the point in their growth that we now need a professional association to allow for more opportunities for participation in advancing learning communities. This is the story of the founding of the new Learning Communities Association.

  8. 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

  9. Student and Community Partner Expectations for Effective Community-Engaged Learning Partnerships

    Science.gov (United States)

    Stack-Cutler, Holly; Dorow, Sara

    2012-01-01

    Student insight and community partner feedback can contribute to understanding and thus improve community-engaged learning practices. Student and community partner voices, however, are not often heard during community-engaged learning development. To ascertain student and community partner expectations for community-engaged learning, thematic…

  10. Elder homelessness. A community perspective.

    Science.gov (United States)

    Bissonnette, A; Hijjazi, K H

    1994-09-01

    Elder homelessness is an increasing problem in our society. After presenting demographics of elder homelessness, this article discusses successful Boston-based program models. Nurse-directed community solutions are emphasized.

  11. Creativity development in community contexts

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre

    2013-01-01

    This article explores the development of creativity in the context of folk art within an urban and rural community in Romania. It adopts a cultural psychological perspective on development, linking it to children's participation in community activities, as well as creativity, considered in relati...... of developmental tendencies and socialisation practices, as well as their implications for how we understand and foster children's creative expression....... to the emergence and use of the symbolic function within child–adult interactions. Easter egg decoration offers an excellent case study for an investigation of children's developing engagement with a cultural practice and, in this research, first and fourth graders (age 7 and 10), from Bucharest and the village......This article explores the development of creativity in the context of folk art within an urban and rural community in Romania. It adopts a cultural psychological perspective on development, linking it to children's participation in community activities, as well as creativity, considered in relation...

  12. Oral Health in Rural Communities

    Science.gov (United States)

    ... Guide Rural Health Topics & States Topics View more Oral Health in Rural Communities Adequate access to oral healthcare ... about oral health programs in my area? What oral health disparities are present in rural America? According to ...

  13. Green Infrastructure for Arid Communities

    Science.gov (United States)

    how green infrastructure practices and the many associated benefits can be effective not only in wetter climates, but also for those communities in arid and semi-arid regions around the nation that have different precipitation patterns

  14. 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.

  15. Being participated: a community approach

    CSIR Research Space (South Africa)

    Winschiers-Theophilus, H

    2010-01-01

    Full Text Available In this paper, we explore the concept of participatory design from a different viewpoint by drawing on an African philosophy of humanness -Ubuntu-, and African rural community practices. The situational dynamics of participatory interaction become...

  16. Local Experiences in Community Health

    Science.gov (United States)

    Fleuret, Sébastien

    2015-01-01

    This paper presents the findings of international research with an original approach anchored in health geography, which illustrates the importance of place as a dimension in community health. The aim of the research is to identify the success factors in the processes used to build community health initiatives at the local level. The study is based on interviews encoded and analysed using the framework of the grounded theory. Three main themes—the place, the community and healthcare supply—and two cross-cutting issues referring to 18 explanatory dimensions are identified. These findings are then put to the test in France through an action research approach. Overall, the work suggest avenues to enable the transferability of successful elements of community health initiatives. PMID:29546124

  17. Local Experiences in Community Health

    Directory of Open Access Journals (Sweden)

    Sébastien Fleuret

    2015-08-01

    Full Text Available This paper presents the findings of international research with an original approach anchored in health geography, which illustrates the importance of place as a dimension in community health. The aim of the research is to identify the success factors in the processes used to build community health initiatives at the local level. The study is based on interviews encoded and analysed using the framework of the grounded theory. Three main themes—the place, the community and healthcare supply—and two cross-cutting issues referring to 18 explanatory dimensions are identified. These findings are then put to the test in France through an action research approach. Overall, the work suggest avenues to enable the transferability of successful elements of community health initiatives.

  18. The Ramathibodi Community Health Program

    Science.gov (United States)

    Buri, Prem; And Others

    1974-01-01

    The Ramathibodi Faculty of Medicine in Bangkok, Thailand, has developed a teaching and research program in community health aimed at brining the institution into close association with the health needs of the country. (Editor)

  19. Resilient communities: implications for professionals

    NARCIS (Netherlands)

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

    2016-01-01

    As a result of societal changes like citizen empowerment and increasing attention for strengthening community resilience, relationships between citizens and professional responders in crisis management are changing. Citizens actively deal with crises themselves, implying adjustments to professional

  20. 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 ...

  1. Theoretical Foundations of Learning Communities

    Science.gov (United States)

    Jessup-Anger, Jody E.

    2015-01-01

    This chapter describes the historical and contemporary theoretical underpinnings of learning communities and argues that there is a need for more complex models in conceptualizing and assessing their effectiveness.

  2. Communities, Livelihoods, and Natural Resources

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

    indigenous knowledge and technologies; multistakeholder approaches; and enhancing community participation in, and benefits from, applied research activities. She has a Master's in Anthropology from McGill University. Email: efajber@idrc.org.in.

  3. Community, Labour and Raymond Williams.

    Science.gov (United States)

    McIlroy, John

    1993-01-01

    Raymond Williams, a British adult educator, believed that community must be at the heart of education and that education must involve the primary organizations of the working class, such as trade unions, to be effective. (SK)

  4. 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.

  5. Using research in community nursing.

    Science.gov (United States)

    Buxton, V; James, T; Harding, W

    The concept of evidence-based medicine has received considerable attention, but the distinctive nature of evidence within community nursing has not been fully explored. This study examines the nature of evidence within community nursing and the factors influencing use of evidence. Although much of the literature has concentrated on individuals as sites of resistance to evidence-based change, the findings of this study suggest that organisational and cultural factors represent more significant obstacles.

  6. 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.

  7. Characterization of the hydrology, water chemistry, and aquatic communities of selected springs in the St. Johns River Water Management District, Florida, 2004

    Science.gov (United States)

    Phelps, G.G.; Walsh, Stephen J.; Gerwig, Robert M.; Tate, William B.

    2006-01-01

    from the Silver Springs group and in both boils at Gemini Springs. No pesticides were detected in water samples from De Leon Spring and Green Spring. Evidence of denitrification was indicated by the presence of excess nitrogen gas in water samples from most of the springs. Aquatic communities varied among the springs. Large floating mats of cyanobacteria (blue-green algae), identified as Lyngbya wollei, were observed in De Leon Spring during all sampling events in 2004. At Gemini Springs, the dominant periphyton was Rhizoclonium sp. Of the three springs sampled for benthic invertebrates, De Leon Spring had the highest overall species richness and most disturbance intolerant species (Florida Index = 4). Green Spring had the lowest species richness of the springs sampled. Based on qualitative comparisons, overall macroinvertebrate species richness seemed to be negatively related to magnesium, potassium, sodium, and specific conductance. Invertebrate abundance was greatest when dissolved oxygen and nitrate were high but phosphorus and potassium concentrations were low. Dipteran abundance seemed to be positively associated with specific conductance and total organic carbon but negatively associated with nitrate-N. Amphipods were the numerically dominant group collected in most (six of nine) collections. Shifts in amphipod abundance of the two species collected (Gammarus sp. and Hyalella azteca) varied by season among the three springs, but there were no trends evident in the variation. Fish populations were relatively species-rich at the Silver Springs group, De Leon Spring, and Gemini Springs, but not at Green Spring. Nonindigenous fish species were observed at all springs except Green Spring.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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

    2017-12-07

    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.

  14. 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

  15. Currents connecting communities: nearshore community similarity and ocean circulation.

    Science.gov (United States)

    Watson, J R; Hays, C G; Raimondi, P T; Mitarai, S; Dong, C; McWilliams, J C; Blanchette, C A; Caselle, J E; Siegel, D A

    2011-06-01

    Understanding the mechanisms that create spatial heterogeneity in species distributions is fundamental to ecology. For nearshore marine systems, most species have a pelagic larval stage where dispersal is strongly influenced by patterns of ocean circulation. Concomitantly, nearshore habitats and the local environment are also influenced by ocean circulation. Because of the shared dependence on the seascape, distinguishing the relative importance of the local environment from regional patterns of dispersal for community structure remains a challenge. Here, we quantify the "oceanographic distance" and "oceanographic asymmetry" between nearshore sites using ocean circulation modeling results. These novel metrics quantify spatial separation based on realistic patterns of ocean circulation, and we explore their explanatory power for intertidal and subtidal community similarity in the Southern California Bight. We find that these metrics show significant correspondence with patterns of community similarity and that their combined explanatory power exceeds that of the thermal structure of the domain. Our approach identifies the unique influence of ocean circulation on community structure and provides evidence for oceanographically mediated dispersal limitation in nearshore marine communities.

  16. Aquatic biological communities and associated habitats at selected sites in the Big Wood River Watershed, south-central Idaho, 2014

    Science.gov (United States)

    MacCoy, Dorene E.; Short, Terry M.

    2016-09-28

    Assessments of streamflow (discharge) parameters, water quality, physical habitat, and biological communities were completed between May and September 2014 as part of a monitoring program in the Big Wood River watershed of south-central Idaho. The sampling was conducted by the U.S. Geological Survey in cooperation with Blaine County, Trout Unlimited, the Nature Conservancy, and the Wood River Land Trust to help identify the status of aquatic resources at selected locations in the watershed. Information in this report provides a basis with which to evaluate and monitor the long-term health of the Big Wood River and its major tributaries. Sampling sites were co-located with existing U.S. Geological Survey streamgaging stations: three on the main stem Big Wood River and four on the North Fork Big Wood River (North Fork), Warm Springs Creek (Warm Sp), Trail Creek (Trail Ck), and East Fork Big Wood River (East Fork) tributaries.The analytical results and quality-assurance information for water quality, physical habitat, and biological community samples collected at study sites during 2 weeks in September 2014 are summarized. Water-quality data include concentrations of major nutrients, suspended sediment, dissolved oxygen, and fecal-coliform bacteria. To assess the potential effects of nutrient enrichment on algal growth, concentrations of periphyton biomass (chlorophyll-a and ash free dry weight) in riffle habitats were determined at each site. Physical habitat parameters include stream channel morphology, habitat volume, instream structure, substrate composition, and riparian vegetative cover. Biological data include taxa richness, abundance, and stream-health indicator metrics for macroinvertebrate and fish communities. Statistical summaries of the water-quality, habitat, and biological data are provided along with discussion of how these findings relate to the health of aquatic resources in the Big Wood River watershed.Seasonal discharge patterns using statistical

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. Enabling community through social media.

    Science.gov (United States)

    Gruzd, Anatoliy; Haythornthwaite, Caroline

    2013-10-31

    Social network analysis provides a perspective and method for inquiring into the structures that comprise online groups and communities. Traces from interaction via social media provide the opportunity for understanding how a community is formed and maintained online. The paper aims to demonstrate how social network analysis provides a vocabulary and set of techniques for examining interaction patterns via social media. Using the case of the #hcsmca online discussion forum, this paper highlights what has been and can be gained by approaching online community from a social network perspective, as well as providing an inside look at the structure of the #hcsmca community. Social network analysis was used to examine structures in a 1-month sample of Twitter messages with the hashtag #hcsmca (3871 tweets, 486 unique posters), which is the tag associated with the social media-supported group Health Care Social Media Canada. Network connections were considered present if the individual was mentioned, replied to, or had a post retweeted. Network analyses revealed patterns of interaction that characterized the community as comprising one component, with a set of core participants prominent in the network due to their connections with others. Analysis showed the social media health content providers were the most influential group based on in-degree centrality. However, there was no preferential attachment among people in the same professional group, indicating that the formation of connections among community members was not constrained by professional status. Network analysis and visualizations provide techniques and a vocabulary for understanding online interaction, as well as insights that can help in understanding what, and who, comprises and sustains a network, and whether community emerges from a network of online interactions.

  2. Integrating Community Expertise into the Academy: South Los Angeles' Community-Academic Model for Partnered Research.

    Science.gov (United States)

    Del Pino, Homero E; Jones, Loretta; Forge, Nell; Martins, David; Morris, D'Ann; Wolf, Kenneth; Baker, Richard; Lucas-Wright, Anna Aziza; Jones, Andrea; Richlin, Laurie; Norris, Keith C

    2016-01-01

    Charles R. Drew University (CDU) and community partners wanted to create a structure to transcend traditional community-academic partnerships. They wanted community leaders integrated into CDU's research goals and education of medical professionals. To explain the establishment of the Community Faculty Program, a new model of community-academic partnership that integrates community and academic knowledge. Using CBPR principles, CDU and community partners re-conceptualized the faculty appointment process and established the Division of Community Engagement (DCE). CDU initially offered academic appointments to nine community leaders. Community Faculty contributes to CDU's governance, education, research, and publication goals. This model engaged communities in translational research and transformed the education of future healthcare professionals. The Community Faculty Program is a new vision of partnership. Using a CBPR approach with committed partners, a Community Faculty Program can be created that embodies the values of both the community and the academy.

  3. 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

  4. 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:

  5. 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.

  6. 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.

  7. Community based research in poor urban Lilongwe

    African Journals Online (AJOL)

    This paper highlights the processes of conducting community-based participatory research within an operational research project in Lilongwe under the title of Extending Services to Communities (ESC). The project involves developing partnerships with community leaders, storekeepers and community members to enhance ...

  8. Thinking about Community Capacity Building & Asset Mapping.

    Science.gov (United States)

    Community Building Resources, Spruce Grove (Alberta).

    This book describes the mindshift that is the key to successful community capacity building and to the development of social and economic structures that nurture local sustainability. Its focus is how the development of community, through community capacity building, connects, animates, and informs citizens. Chapter I introduces community building…

  9. Evaluation of the Community School Concept.

    Science.gov (United States)

    Ediger, Marlow

    This paper explores the concept of the community school. A community school emphasizes wholehearted involvement by all living in the designated community area. The Porter Rural School, Missouri, established by Marie Turner Harvey with the help of Evelyn Dewey and her father John Dewey, was an outstanding example of the community school concept…

  10. Corporate Social Responsibility Agreements Model for Community ...

    African Journals Online (AJOL)

    Corporate Social Responsibility Agreements Model for Community Development: The Case of Golden Star (Bogoso/Prestea) Limited and its Mine Local Community. ... of making voluntary contributions towards community development to making sustainable community development an integral part of the mining business.

  11. 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...

  12. 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…

  13. 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

  14. Technical Evaluation Report 34: Growing Virtual Communities

    Directory of Open Access Journals (Sweden)

    Debbie Garber

    2004-08-01

    Full Text Available As online collaborative technologies become easier to use, an increasing range of “virtual communities” are being established, often for educational purposes. This report stresses that an efficient technology is only part of the process underlying a successful online community. It considers the social process on which an online learning community must be founded if it is to flourish and be useful. Definitions of community, learning community, and virtual learning community are reviewed, and the experience of an online community member is discussed. The importance of nurturing the community’s health, and the natural life cycle of a virtual community, are examined.

  15. Climate change, science and community.

    Science.gov (United States)

    Kim, Hak-Soo

    2012-04-01

    Climate change offers serious challenges to the effectiveness of science, communication, and community. It demands us to look back upon what we have done in regard to science and technology. In addition, it leads us to examine human efforts invested to solve collective, shared problems by communication and community. The process of behavior per se is found to be greatly overlooked in the establishment sciences, both natural and social, and in both theory and practice. A theory of behavior is introduced and explicated as a platform to solve such commons' problems as climate change. Finally, we find principled ways to improve effectiveness of communication and community by developing human capabilities so that we can win our battle against climate change and other potential tragedies of the commons.

  16. Conceptualizing age-friendly communities.

    Science.gov (United States)

    Menec, Verena H; Means, Robin; Keating, Norah; Parkhurst, Graham; Eales, Jacquie

    2011-09-01

    On the political and policy front, interest has increased in making communities more "age-friendly", an ongoing trend since the World Health Organization launched its global Age-Friendly Cities project. We conceptualize age-friendly communities by building on the WHO framework and applying an ecological perspective. We thereby aim to make explicit key assumptions of the interplay between the person and the environment to advance research or policy decisions in this area. Ecological premises (e.g., there must be a fit between the older adult and environmental conditions) suggest the need for a holistic and interdisciplinary research approach. Such an approach is needed because age-friendly domains (the physical environment, housing, the social environment, opportunities for participation, informal and formal community supports and health services, transportation, communication, and information) cannot be treated in isolation from intrapersonal factors, such as age, gender, income, and functional status, and other levels of influence, including the policy environment.

  17. 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.

  18. 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.

  19. Collaborating to Create Healthier Communities.

    Science.gov (United States)

    Scarbrough, Amanda W; Hill, Jack; Rodriguez, Jesus

    2017-01-01

    The Montgomery County United Way and Sam Houston State University explored existing public health and community-based issues and associated assets and gaps within Montgomery County, Texas, through the integration of quantitative geospatial data, demographic information, and the application of geographical information systems. The intent of the initial results was to use maps to visually compare the magnitude of significant emerging health issues in Montgomery County with other counties across Texas in an effort to better educate and increase the awareness of the general public within Montgomery County. The second objective was to present an example of the visual effect and impact of the overall spatial analysis and mapping process with a focus on a specific community issue that could likely be addressed and potentially solved in a relatively short amount of time. This second and more spatially detailed aspect of the evaluation resulted in the creation of an asset map that presented high concentrations or densities of payday loan services in Montgomery County. Recognizing the potential risks of payday loans, Montgomery County United Way presented the asset maps to the effected community leaders. Upon review, leaders discovered there were dense clusters of payday loan sites in areas with high rates of poverty. Prior to the creation of this aggregated payday loan business location map, an individual in a community typically only saw one, or two at the most, payday loan business during a daily commute. Within a very short period and through a grassroots effort to improve community well-being, there were significant formal and positive changes made by the community.

  20. Technical Evaluation Report 34: Growing Virtual Communities

    OpenAIRE

    Debbie Garber

    2004-01-01

    As online collaborative technologies become easier to use, an increasing range of “virtual communities” are being established, often for educational purposes. This report stresses that an efficient technology is only part of the process underlying a successful online community. It considers the social process on which an online learning community must be founded if it is to flourish and be useful. Definitions of community, learning community, and virtual learning community are reviewed, and t...

  1. African-Americans in Community Colleges. UCLA Community College Bibliography

    Science.gov (United States)

    McJunkin, Kyle Stewart

    2005-01-01

    Recent literature on African Americans students at the community college level represents an eclectic body of material. Broadly speaking, this literature has focused on questions concerning African American learning styles, cultural determinants to success, retention issues, and comparative achievement with other minority groups. While the…

  2. 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.

  3. UCLA Community College Bibliography: Nursing Education and Community Colleges

    Science.gov (United States)

    Liu, Amy

    2007-01-01

    The references presented in this bibliography provide an overview of recent scholarship concerning associate degree nursing students, faculty, and pedagogy at community colleges. Included in this bibliography are studies that incorporate a variety of methodologies ranging from quasi-experimental, case study, and naturalistic inquiry to correlation…

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

    African Journals Online (AJOL)

    Access to land among land-poor households has always been contentious. In Malawi, the government, aware of this, started Community Based Rural Based Land Development Project (CBRLDP), financed by the World Bank. The project brought to the fore the latent antagonistic relationship between immigrants and host ...

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

    African Journals Online (AJOL)

    government, aware of this, started Community Based Rural Based Land Development Project. (CBRLDP), financed by the World Bank. .... his perspective on the issue. It also benefitted from a review of ..... they did not subdue the Yao who, through their contacts with Arab slave traders, had access to superior weapons ...

  6. 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...

  7. 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…

  8. Kothmale Community Radio Interorg Project: True Community Radio or Feel-Good Propaganda?

    Science.gov (United States)

    Harvey-Carter, Liz

    2009-01-01

    The Kothmale Community Radio and Interorg project in Sri Lanka has been hailed as an example of how a community radio initiative should function in a developing nation. However, there is some question about whether the Kothmale Community Interorg Project is a true community radio initiative that empowers local communities to access ICT services…

  9. School-Community Relations, Community Support, and Student Achievement: A Summary of Findings.

    Science.gov (United States)

    Bowles, B. Dean

    Summaries of four studies on school community relations, student achievement and community support are provided in this report. The studies abstracted are: (1) "School-Community Relations, Student Achievement, and Conflict Resolution," by John E. Ingram, Jr.; (2) "School-Community Relations and Student Achievement in Communities of Differing…

  10. 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)

  11. Novelzine: Reading and Writing Community

    Science.gov (United States)

    deGravelles, Karin H.; Bach, Jacqueline; Hyde, Yvette; Hebert, Angelle

    2012-01-01

    How might team teaching, young adult novels, and zines work together to engage students in thinking about, writing about, and building community? Four researchers worked with three eighth-grade English teachers and one student teacher to find out. The four eighth-grade English teachers teach as a team, meeting formally at least once a week to plan…

  12. Supporting the GLAST User Community

    Science.gov (United States)

    Band, David L.

    2004-01-01

    The Gamma-ray Large Area Space Telescope (GLAST) Science Support Center (GSSC) is the scientific community's interface with GLAST. The GSSC will provide data, analysis software and documentation. In addition, the GSSC will administer the guest investigator program for NASA HQ. Consequently, the GSSC will provide proposal preparation tools to assist proposers in assessing the feasibility of observing sources of interest.

  13. Offshore Fish Community: Ecological Interactions

    Science.gov (United States)

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone...

  14. Planning Schools for Rural Communities.

    Science.gov (United States)

    Harmon, Hobart; Howley, Craig; Smith, Charles; Dickens, Ben

    School improvement in rural places cannot succeed without attention to the rural context of learning. Most especially, smaller schools need to be preserved and sustained in rural areas, particularly impoverished communities, for the sake of student achievement and personal development. This school improvement tool suggests the character of a "good…

  15. COMMUNITY HEALTH & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    user

    Early detection and treatment of these morbidities could prevent deterioration. The aim of the survey was to determine and compare the prevalence of ..... interventions. Increasing the detection rate of mental morbidity in the community is fundamental. The inclusion of mental health care as a component of primary health ...

  16. Planning positive legacies for communities

    DEFF Research Database (Denmark)

    Pacheco Cueva, Vladimir

    2012-01-01

    In the last 3 decades, an increasing number of mining and resources companies around the world have established community funds, trusts and foundations (FTFs) in order to comply with government legislation and/or to promote their corporate social responsibility or philanthropic programmes...

  17. Building Community through Arts Experiences.

    Science.gov (United States)

    Arnold, Alice

    1994-01-01

    Asserts that society is fragmented and there is a need for strong support networks. Describes a cooperative community building program in North Carolina involving East Carolina University's art education program, Greenville (NC) public schools, and the McDonalds corporation. (CFR)

  18. Universities' perspectives on community engagement

    NARCIS (Netherlands)

    Benneworth, Paul Stephen; Humphrey, L.; Benneworth, P.

    2012-01-01

    This chapter makes the argument that despite the fact that utility has always been important to why universities exist, engaging with communities has been framed in ways that reinforce its perception as a transient, peripheral and even undesirable activity. The chapter begins by noting the way that

  19. & PRIMARY HEALTH CARE COMMUNITY MEDICINE

    African Journals Online (AJOL)

    to improving mood and helping to manage stress . physical activity a day at least five times a week . Sedentary lifestyle is associated with obesity, Greater health benefits can be experienced with. KEYWORDS. Practice,. Exercise,. Leisure,. Work- related,. Overweight,. Obesity. Journal of Community Medicine and Primary ...

  20. COMMUNITY MEDICINE & PRIMARY HEALTH CARE

    African Journals Online (AJOL)

    Objective: The study aimed at involving adolescents in school-based health promotion activities as a strategy to improve ... Adolescents, perception of risk, sexual behaviour, active participation, health promotion. journal of. COMMUNITY MEDICINE. & PRIMARY HEALTH CARE .... behaviour, importance of self esteem and.