WorldWideScience

Sample records for bacterial ecological strategies

  1. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    compounds these must first be undergo extracellular hydrolysis. Bacteria have a great diversity with respect to types of metabolism that far exceeds the metabolic repertoire of eukaryotic organisms. Bacteria play a fundamental role in the biosphere and certain key processes such as, for example......, the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  2. Soil-covered strategy for ecological restoration alters the bacterial community structure and predictive energy metabolic functions in mine tailings profiles.

    Science.gov (United States)

    Li, Yang; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2017-03-01

    Native soil amendment has been widely used to stabilize mine tailings and speed up the development of soil biogeochemical functions before revegetation; however, it remains poorly understood about the response of microbial communities to ecological restoration of mine tailings with soil-covered strategy. In this study, microbial communities along a 60-cm profile were investigated in mine tailings during ecological restoration of two revegetation strategies (directly revegetation and native soil covered) with different plant species. The mine tailings were covered by native soils as thick as 40 cm for more than 10 years, and the total nitrogen, total organic carbon, water content, and heavy metal (Fe, Cu, and Zn) contents in the 0-40 cm intervals of profiles were changed. In addition, increased microbial diversity and changed microbial community structure were also found in the 10-40 cm intervals of profiles in soil-covered area. Soil-covered strategy rather than plant species and soil depth was the main factor influencing the bacterial community, which explained the largest portion (29.96%) of the observed variation. Compared directly to revegetation, soil-covered strategy exhibited the higher relative abundance of Acidobacteria and Deltaproteobacteria and the lower relative abundance of Bacteroidetes, Gemmatimonadetes, Betaproteobacteria, and Gammaproteobacteria. PICRUSt analysis further demonstrated that soil-covered caused energy metabolic functional changes in carbon, nitrogen, and sulfur metabolism. Given all these, the soil-covered strategy may be used to fast-track the establishment of native microbial communities and is conducive to the rehabilitation of biogeochemical processes for establishing native plant species.

  3. Bacterial strategies of resistance to antimicrobial peptides.

    Science.gov (United States)

    Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

    2016-05-26

    Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

  4. Bacterial - Fungal Interactions: ecology, mechanisms and challenges.

    Science.gov (United States)

    Deveau, A; Bonito, G; Uehling, J; Paoletti, M; Becker, M; Bindschedler, S; Hacquard, S; Hervé, V; Labbé, J; Lastovetsky, O A; Mieszkin, S; Millet, L J; Vajna, B; Junier, P; Bonfante, P; Krom, B P; Olsson, S; Elsas, J D van; Wick, L Y

    2018-02-19

    Fungi and bacteria are found living together in a wide variety of environments. Their interactions are significant drivers of many ecosystem functions and are important for the health of plants and animals. A large number of fungal and bacterial families are engaged in complex interactions that lead to critical behavioural shifts of the microorganisms ranging from mutualism to pathogenicity. The importance of bacterial-fungal interactions (BFI) in environmental science, medicine and biotechnology has led to the emergence of a dynamic and multidisciplinary research field that combines highly diverse approaches including molecular biology, genomics, geochemistry, chemical and microbial ecology, biophysics and ecological modelling. In this review, we discuss most recent advances that underscore the roles of BFI across relevant habitats and ecosystems. A particular focus is placed on the understanding of BFI within complex microbial communities and in regards of the metaorganism concept. We also discuss recent discoveries that clarify the (molecular) mechanisms involved in bacterial-fungal relationships, and the contribution of new technologies to decipher generic principles of BFI in terms of physical associations and molecular dialogues. Finally, we discuss future directions for researches in order to catalyse a synergy within the BFI research area and to resolve outstanding questions.

  5. Water Saving Strategies & Ecological Modernisation

    DEFF Research Database (Denmark)

    Hoffmann, Birgitte; Jensen, Jesper Ole; Elle, Morten

    2005-01-01

    Drawing on case studies of water saving campaigns and new collaborations, the pa-per will serve, on the one hand, as an interpretation of the water saving strategy in Co-penhagen in the light of Ecological Modernisation, and on the other hand, as a critical discussion of Ecological Modernisation...... as a frame for understanding resource manage-ment. The water management in Copenhagen has in recent years undergone a rather radi-cal transition. Along with strong drivers for resource management in the region the mu-nicipal water supplier has tested and implemented a number of initiatives to promote sus...... to 125 l/capita/day in 2002. A series of different strategies, targets and tools have been implemented: Emphasizing demand side instead of supply side, using and communicating indicators, formulating goals for reducing water consumption and developing learning processes in water management. A main...

  6. Bacterial signaling ecology and potential applications during aquatic biofilm construction.

    Science.gov (United States)

    Vega, Leticia M; Alvarez, Pedro J; McLean, Robert J C

    2014-07-01

    In their natural environment, bacteria and other microorganisms typically grow as surface-adherent biofilm communities. Cell signal processes, including quorum signaling, are now recognized as being intimately involved in the development and function of biofilms. In contrast to their planktonic (unattached) counterparts, bacteria within biofilms are notoriously resistant to many traditional antimicrobial agents and so represent a major challenge in industry and medicine. Although biofilms impact many human activities, they actually represent an ancient mode of bacterial growth as shown in the fossil record. Consequently, many aquatic organisms have evolved strategies involving signal manipulation to control or co-exist with biofilms. Here, we review the chemical ecology of biofilms and propose mechanisms whereby signal manipulation can be used to promote or control biofilms.

  7. Ecological strategies shapes the insurance potential of biodiversity

    Directory of Open Access Journals (Sweden)

    Miguel eMatias

    2013-01-01

    Full Text Available Biodiversity is thought to provide insurance for ecosystem functioning under heterogeneous environments, however, such insurance potential is under serious threat following unprecedented loss of biodiversity. One of the key mechanism underlying ecological insurance is that niche differentiation allows asynchronous responses to fluctuating environments; although, the role of different ecological strategies (e.g. specialists vs generalists has yet to be formally evaluated. We combine here a simple model and experimental study to illustrate how different specialization-performance strategies shape the biodiversity-insurance relationship. We assembled microcosm of generalists and specialist bacteria over a gradient of salinity and found that, bacterial communities made up of generalists were more productive and more stable over time under environmental fluctuations. We argue that beyond species richness itself, it is essential to incorporate the distribution of ecological strategies across relevant environmental gradients as predictors of the insurance potential of biodiversity in natural ecosystems.

  8. Microbial ecology of bacterially mediated PCB biodegradation

    International Nuclear Information System (INIS)

    Pettigrew, C.A. Jr.

    1989-01-01

    The roles of plasmid mediated and consortia mediated polychlorinated biphenyl (PCB) biodegradation by bacterial populations isolated from PCB contaminated freshwater sediments were investigated. PCB degrading bacteria were isolated by DNA:DNA colony hybridization, batch enrichments, and chemostat enrichment. Analysis of substrate removal and metabolite production were done using chlorinated biphenyl spray plates, reverse phase high pressure liquid chromatography, Cl - detection, and 14 C-labeled substrate mineralization methods. A bacterial consortium, designated LPS10, involved in a concerted metabolic attack on chlorinated biphenyls, was shown to mineralize 4-chlorobiphenyl (4CB) and 4,4'-dichlorobiphenyl (4,4' CB). The LPS10 consortium was isolated by both batch and chemostat enrichment using 4CB and biphenyl (BP) as sole carbon source and was found to have tree bacterial isolates that predominated; these included: Pseudomonas, testosteroni LPS10A which mediated the breakdown of 4CB and 4,4' CB to the putative meta-cleavage product and subsequently to 4-chlorobenzoic acid (4CBA), an isolate tentatively identified as an Arthrobacter sp. LPS10B which mediated 4CBA degradation, and Pseudomonas putida by A LPS10C whose role in the consortium has not been determined

  9. DECISION STRATEGIES AND COGNITIVE ADAPTATIONS TO ECOLOGY

    Directory of Open Access Journals (Sweden)

    Poleszczuk Jan

    2017-06-01

    Full Text Available In this paper, I discuss the concept of adaptive rationality. I present a simple model of ecology and the set of decision rules. The basic structure of the process of cognitive adaptation to ecology is described as a structure comprising (1 perceptual space, (2 a function valuating perceived items, (3 a set of available decision rules and (4 the adaptation process - identification and selection of the best strategies in given ecological conditions. The presented model of ecosystem allows a conclusion that completely opposite strategies may be compatible with the assumption of adaptive rationality.

  10. Sustainable strategies for treatment of bacterial infections

    DEFF Research Database (Denmark)

    Molin, Søren

    2014-01-01

    Resistance to antibiotics and the consequential failures of treatment based on antibiotics makes microbial infections a major threat to human health. This problem combined with rapidly increasing life-style disease problems challenge our healtcare system as well as the pharma industry, and if we do...... not in a foreseeable future develop novel approaches and strategies to combat bacterial infections, many people will be at risk of dying from even trivial infections for which we until recently had highly effective antibiotics. We have for a number of years investigated chronic bacterial lung infections in patients...... suffering from cystic fibrosis. These infections are optimal model scenarios for studies of antibiotic resistance development and microbial adaptation, and we suggest that this information should be useful when designing new anti-microbial strategies. In this respect it will be important to choose...

  11. Bacterial diversity and ecological function in lake water bodies

    OpenAIRE

    Lijuan Ren; Dan He; Peng Xing; Yujing Wang; Qinglong Wu

    2013-01-01

    The healthy development of lake ecosystems is a global issue. Bacteria are not only an integral component of food webs, but also play a key role in controlling and regulating water quality in lake ecosystems. Hence, in order to provide some suggestions for maintaining the long-term and healthy development of lake ecosystems, this review discusses and analyses concepts and assessment of bacterial diversity, the distribution of bacteria communities, mechanisms of formation, and the ecological f...

  12. Bacterial motility in the sea and its ecological implications

    DEFF Research Database (Denmark)

    Grossart, Hans-Peter; Riemann, Lasse; Azam, F.

    2001-01-01

    the coast of La Jolla, California, as well as a mesocosm study to examine bacterial motility and its relationship to environmental variables. Dark-field microscopy revealed periods of sustained low (fall and winter, ...). Bacteria in natural seawater did not swim constantly nor at constant speeds; over 40% swam algae, bacteria...... swimming. Our results show that a variable fraction of marine bacteria is able to respond to loci of organic matter, e.g. organic particles and algae, and that motility underlies dynamic patterns of ecological relationships (symbiosis, competition, parasitism) between bacteria and algae. Since motility may...

  13. Contrasting spatial patterns and ecological attributes of soil bacterial and archaeal taxa across a landscape.

    Science.gov (United States)

    Constancias, Florentin; Saby, Nicolas P A; Terrat, Sébastien; Dequiedt, Samuel; Horrigue, Wallid; Nowak, Virginie; Guillemin, Jean-Philippe; Biju-Duval, Luc; Chemidlin Prévost-Bouré, Nicolas; Ranjard, Lionel

    2015-06-01

    ) according to phyla. Altogether, this study provided valuable clues about the ecological behavior of soil bacterial and archaeal taxa at an agricultural landscape scale and could be useful for developing sustainable strategies of land management. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  14. Growth strategy of heterotrophic bacterial population along successional sequence on spoil of brown coal colliery substrate

    Czech Academy of Sciences Publication Activity Database

    Krištůfek, Václav; Elhottová, Dana; Chroňáková, Alica; Dostálková, I.; Picek, T.; Kalčík, Jiří

    2005-01-01

    Roč. 50, č. 5 (2005), s. 427-435 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA526/03/1259 Institutional research plan: CEZ:AV0Z60660521 Keywords : growth strategy * heterotrophic bacterial population * brown coal colliery spoil Subject RIV: EH - Ecology, Behaviour Impact factor: 0.918, year: 2005

  15. Estimating bacterial diversity for ecological studies: methods, metrics, and assumptions.

    Directory of Open Access Journals (Sweden)

    Julia Birtel

    Full Text Available Methods to estimate microbial diversity have developed rapidly in an effort to understand the distribution and diversity of microorganisms in natural environments. For bacterial communities, the 16S rRNA gene is the phylogenetic marker gene of choice, but most studies select only a specific region of the 16S rRNA to estimate bacterial diversity. Whereas biases derived from from DNA extraction, primer choice and PCR amplification are well documented, we here address how the choice of variable region can influence a wide range of standard ecological metrics, such as species richness, phylogenetic diversity, β-diversity and rank-abundance distributions. We have used Illumina paired-end sequencing to estimate the bacterial diversity of 20 natural lakes across Switzerland derived from three trimmed variable 16S rRNA regions (V3, V4, V5. Species richness, phylogenetic diversity, community composition, β-diversity, and rank-abundance distributions differed significantly between 16S rRNA regions. Overall, patterns of diversity quantified by the V3 and V5 regions were more similar to one another than those assessed by the V4 region. Similar results were obtained when analyzing the datasets with different sequence similarity thresholds used during sequences clustering and when the same analysis was used on a reference dataset of sequences from the Greengenes database. In addition we also measured species richness from the same lake samples using ARISA Fingerprinting, but did not find a strong relationship between species richness estimated by Illumina and ARISA. We conclude that the selection of 16S rRNA region significantly influences the estimation of bacterial diversity and species distributions and that caution is warranted when comparing data from different variable regions as well as when using different sequencing techniques.

  16. Strategies for managing rival bacterial communities: Lessons from burying beetles.

    Science.gov (United States)

    Duarte, Ana; Welch, Martin; Swannack, Chris; Wagner, Josef; Kilner, Rebecca M

    2018-03-01

    The role of bacteria in animal development, ecology and evolution is increasingly well understood, yet little is known of how animal behaviour affects bacterial communities. Animals that benefit from defending a key resource from microbial competitors are likely to evolve behaviours to control or manipulate the animal's associated external microbiota. We describe four possible mechanisms by which animals could gain a competitive edge by disrupting a rival bacterial community: "weeding," "seeding," "replanting" and "preserving." By combining detailed behavioural observations with molecular and bioinformatic analyses, we then test which of these mechanisms best explains how burying beetles, Nicrophorus vespilloides, manipulate the bacterial communities on their carcass breeding resource. Burying beetles are a suitable species to study how animals manage external microbiota because reproduction revolves around a small vertebrate carcass. Parents shave a carcass and apply antimicrobial exudates on its surface, shaping it into an edible nest for their offspring. We compared bacterial communities in mice carcasses that were either fresh, prepared by beetles or unprepared but buried underground for the same length of time. We also analysed bacterial communities in the burying beetle's gut, during and after breeding, to understand whether beetles could be "seeding" the carcass with particular microbes. We show that burying beetles do not "preserve" the carcass by reducing bacterial load, as is commonly supposed. Instead, our results suggest they "seed" the carcass with bacterial groups which are part of the Nicrophorus core microbiome. They may also "replant" other bacteria from the carcass gut onto the surface of their carrion nest. Both these processes may lead to the observed increase in bacterial load on the carcass surface in the presence of beetles. Beetles may also "weed" the bacterial community by eliminating some groups of bacteria on the carcass, perhaps through

  17. Strategies for combating bacterial biofilm infections

    DEFF Research Database (Denmark)

    Wu, Hong; Moser, Claus Ernst; Wang, Heng-Zhuang

    2015-01-01

    Formation of biofilm is a survival strategy for bacteria and fungi to adapt to their living environment, especially in the hostile environment. Under the protection of biofilm, microbial cells in biofilm become tolerant and resistant to antibiotics and the immune responses, which increases the di.......International Journal of Oral Science advance online publication, 12 December 2014; doi:10.1038/ijos.2014.65....

  18. Big Canyon Creek Ecological Restoration Strategy.

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Lynn; Richardson, Shannon

    2007-10-01

    He-yey, Nez Perce for steelhead or rainbow trout (Oncorhynchus mykiss), are a culturally and ecologically significant resource within the Big Canyon Creek watershed; they are also part of the federally listed Snake River Basin Steelhead DPS. The majority of the Big Canyon Creek drainage is considered critical habitat for that DPS as well as for the federally listed Snake River fall chinook (Oncorhynchus tshawytscha) ESU. The Nez Perce Soil and Water Conservation District (District) and the Nez Perce Tribe Department of Fisheries Resources Management-Watershed (Tribe), in an effort to support the continued existence of these and other aquatic species, have developed this document to direct funding toward priority restoration projects in priority areas for the Big Canyon Creek watershed. In order to achieve this, the District and the Tribe: (1) Developed a working group and technical team composed of managers from a variety of stakeholders within the basin; (2) Established geographically distinct sub-watershed areas called Assessment Units (AUs); (3) Created a prioritization framework for the AUs and prioritized them; and (4) Developed treatment strategies to utilize within the prioritized AUs. Assessment Units were delineated by significant shifts in sampled juvenile O. mykiss (steelhead/rainbow trout) densities, which were found to fall at fish passage barriers. The prioritization framework considered four aspects critical to determining the relative importance of performing restoration in a certain area: density of critical fish species, physical condition of the AU, water quantity, and water quality. It was established, through vigorous data analysis within these four areas, that the geographic priority areas for restoration within the Big Canyon Creek watershed are Big Canyon Creek from stream km 45.5 to the headwaters, Little Canyon from km 15 to 30, the mainstem corridors of Big Canyon (mouth to 7km) and Little Canyon (mouth to 7km). The District and the Tribe

  19. A territorial classification for the ecological strategy

    International Nuclear Information System (INIS)

    Arias de Greiff, Jorge

    2002-01-01

    The author proposes a territorial classification including at the sun, the water, the atmosphere, the vegetable earth and the vegetation of green leaf, describes each one of the elements, he refers to the micro-climates and he gives a territorial organization for the ecological emergency

  20. Consequences of packaging on bacterial growth. Meat is an ecological niche.

    Science.gov (United States)

    Labadie, J

    1999-07-01

    Meat is a good support for bacterial growth and particularly for bacteria which are specific of meat and meat products. Little is known about the physiological and biochemical factors which could explain why some bacterial species are only isolated from meat. This review tentatively points out, from an ecological point of view, some of these factors in Gram negative and Gram positive micro-organisms influencing storage life.

  1. Bacterial Communities of Diverse Drosophila Species: Ecological Context of a Host–Microbe Model System

    Science.gov (United States)

    Bhatnagar, Srijak; Eisen, Jonathan A.; Kopp, Artyom

    2011-01-01

    Drosophila melanogaster is emerging as an important model of non-pathogenic host–microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal–microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host–microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host–microbe interactions. Bacterial taxa used in experimental studies are rare or absent in

  2. Differential Ecological Specificity of Protist and Bacterial Microbiomes across a Set of Termite Species

    Directory of Open Access Journals (Sweden)

    Lena Waidele

    2017-12-01

    Full Text Available The gut microbiome of lower termites comprises protists and bacteria that help these insects to digest cellulose and to thrive on wood. The composition of the termite gut microbiome correlates with phylogenetic distance of the animal host and host ecology (diet in termites collected from their natural environment. However, carryover of transient microbes from host collection sites are an experimental concern and might contribute to the ecological imprints on the termite gut microbiome. Here, we set out to test whether an ecological imprint on the termite gut microbiome remains, when focusing on the persistent microbiome. Therefore, we kept five termite species under strictly controlled dietary conditions and subsequently profiled their protist and bacterial gut microbial communities using 18S and 16S rRNA gene amplicon sequencing. The species differed in their ecology; while three of the investigated species were wood-dwellers that feed on the piece of wood they live in and never leave except for the mating flight, the other two species were foragers that regularly leave their nests to forage for food. Despite these prominent ecological differences, protist microbiome structure aligned with phylogenetic relatedness of termite host species. Conversely, bacterial communities seemed more flexible, suggesting that microbiome structure aligned more strongly with the foraging and wood-dwelling ecologies. Interestingly, protist and bacterial community alpha-diversity correlated, suggesting either putative interactions between protists and bacteria, or that both types of microbes in the termite gut follow shared structuring principles. Taken together, our results add to the notion that bacterial communities are more variable over evolutionary time than protist communities and might react more flexibly to changes in host ecology.

  3. Differential Ecological Specificity of Protist and Bacterial Microbiomes across a Set of Termite Species

    KAUST Repository

    Waidele, Lena

    2017-12-19

    The gut microbiome of lower termites comprises protists and bacteria that help these insects to digest cellulose and to thrive on wood. The composition of the termite gut microbiome correlates with phylogenetic distance of the animal host and host ecology (diet) in termites collected from their natural environment. However, carryover of transient microbes from host collection sites are an experimental concern and might contribute to the ecological imprints on the termite gut microbiome. Here, we set out to test whether an ecological imprint on the termite gut microbiome remains, when focusing on the persistent microbiome. Therefore, we kept five termite species under strictly controlled dietary conditions and subsequently profiled their protist and bacterial gut microbial communities using 18S and 16S rRNA gene amplicon sequencing. The species differed in their ecology; while three of the investigated species were wood-dwellers that feed on the piece of wood they live in and never leave except for the mating flight, the other two species were foragers that regularly leave their nests to forage for food. Despite these prominent ecological differences, protist microbiome structure aligned with phylogenetic relatedness of termite host species. Conversely, bacterial communities seemed more flexible, suggesting that microbiome structure aligned more strongly with the foraging and wood-dwelling ecologies. Interestingly, protist and bacterial community alpha-diversity correlated, suggesting either putative interactions between protists and bacteria, or that both types of microbes in the termite gut follow shared structuring principles. Taken together, our results add to the notion that bacterial communities are more variable over evolutionary time than protist communities and might react more flexibly to changes in host ecology.

  4. Bacterial ecology of abattoir wastewater treated by an anaerobic digestor

    Directory of Open Access Journals (Sweden)

    Linda Jabari

    2016-03-01

    Full Text Available Abstract Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens, and msbl6 (candidate division were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published.

  5. Bacterial ecology of abattoir wastewater treated by an anaerobic digestor.

    Science.gov (United States)

    Jabari, Linda; Gannoun, Hana; Khelifi, Eltaief; Cayol, Jean-Luc; Godon, Jean-Jacques; Hamdi, Moktar; Fardeau, Marie-Laure

    2016-01-01

    Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published. Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  6. Plumage bacterial assemblages in a breeding wild passerine: relationships with ecological factors and body condition.

    Science.gov (United States)

    Saag, Pauli; Tilgar, Vallo; Mänd, Raivo; Kilgas, Priit; Mägi, Marko

    2011-05-01

    Microorganisms have been shown to play an important role in shaping the life histories of animals, and it has recently been suggested that feather-degrading bacteria influence the trade-off between parental effort and self-preening behavior in birds. We studied a wild breeding population of great tits (Parus major) to explore habitat-, seasonal-, and sex-related variation in feather-degrading and free-living bacteria inhabiting the birds' yellow ventral feathers and to investigate associations with body condition. The density and species richness of bacterial assemblages was studied using flow cytometry and ribosomal intergenic spacer analysis. The density of studied bacteria declined between the nest-building period and the first brood. The number of bacterial phylotypes per bird was higher in coniferous habitat, while bacterial densities were higher in deciduous habitat. Free-living bacterial density was positively correlated with female mass; conversely, there was a negative correlation between attached bacterial density and female mass during the period of peak reproductive effort. Bacterial species richness was sex dependent, with more diverse bacterial assemblages present on males than females. Thus, this study revealed that bacterial assemblages on the feathers of breeding birds are affected both by life history and ecological factors and are related to body condition.

  7. Strategy for an assessment of cumulative ecological impacts

    International Nuclear Information System (INIS)

    Boucher, P.; Collins, J.; Nelsen, J.

    1995-01-01

    The US Department of Energy (DOE) has developed a strategy to conduct an assessment of the cumulative ecological impact of operations at the 300-square-mile Savannah River Site. This facility has over 400 identified waste units and contains several large watersheds. In addition to individual waste units, residual contamination must be evaluated in terms of its contribution to ecological risks at zonal and site-wide levels. DOE must be able to generate sufficient information to facilitate cleanup in the immediate future within the context of a site-wide ecological risk assessment that may not be completed for many years. The strategy superimposes a more global perspective on ecological assessments of individual waste units and provides strategic underpinnings for conducting individual screening-level and baseline risk assessments at the operable unit and zonal or watershed levels. It identifies ecological endpoints and risk assessment tools appropriate for each level of the risk assessment. In addition, it provides a clear mechanism for identifying clean sites through screening-level risk assessments and for elevating sites with residual contamination to the next level of assessment. Whereas screening-level and operable unit-level risk assessments relate directly to cleanup, zonal and site-wide assessments verity or confirm the overall effectiveness of remediation. The latter assessments must show, for example, whether multiple small areas with residual pesticide contamination that have minimal individual impact would pose a cumulative risk from bioaccumulation because they are within the habitat range of an ecological receptor

  8. Plant Ecological Strategies Shift Across the Cretaceous–Paleogene Boundary

    Science.gov (United States)

    Blonder, Benjamin; Royer, Dana L.; Johnson, Kirk R.; Miller, Ian; Enquist, Brian J.

    2014-01-01

    The Chicxulub bolide impact caused the end-Cretaceous mass extinction of plants, but the associated selectivity and ecological effects are poorly known. Using a unique set of North Dakota leaf fossil assemblages spanning 2.2 Myr across the event, we show among angiosperms a reduction of ecological strategies and selection for fast-growth strategies consistent with a hypothesized recovery from an impact winter. Leaf mass per area (carbon investment) decreased in both mean and variance, while vein density (carbon assimilation rate) increased in mean, consistent with a shift towards “fast” growth strategies. Plant extinction from the bolide impact resulted in a shift in functional trait space that likely had broad consequences for ecosystem functioning. PMID:25225914

  9. Wetland management strategies lead to tradeoffs in ecological structure and function

    Directory of Open Access Journals (Sweden)

    Ariane L. Peralta

    2017-12-01

    Full Text Available Anthropogenic legacy effects often occur as a consequence of land use change or land management and can leave behind long-lasting changes to ecosystem structure and function. This legacy is described as a memory in the form of ecological structure or ecological interactions that remains at a location from a previous condition. We examined how forested floodplain restoration strategy, based on planting intensity, influenced wetland community structure and soil chemical and physical factors after 15 years. The site was divided into 15 strips, and strips were assigned to one of five restoration treatments: plantings of acorns, 2-year-old seedlings, 5-ft bareroot trees, balled and burlapped trees, and natural seed bank regeneration. Our community composition survey revealed that plots planted with bareroot or balled and burlapped trees developed closed tree canopies with little herbaceous understory, while acorn plantings and natural colonization plots developed into dense stands of the invasive species reed canary grass (RCG; 'Phalaris arundinacea'. Restoration strategy influenced bacterial community composition but to a lesser degree compared to the plant community response, and riverine hydrology and restoration strategy influenced wetland soil conditions. Soil ammonium concentrations and pH were similar across all wetland restoration treatments, while total organic carbon was highest in forest and RCG-dominated plots compared to mixed patches of trees and open areas. The differences in restoration strategy and associated economic investment resulted in ecological tradeoffs. The upfront investment in larger, more mature trees (i.e., bareroot, balled and burlapped led to floodplain forested communities, while cheaper, more passive planting strategies (i.e., seedlings, seedbank, or acorns resulted in dense stands of invasive RCG, despite the similar floodplain hydrology across all sites. Therefore, recovery of multiple ecosystem services that

  10. Biofuel components change the ecology of bacterial volatile petroleum hydrocarbon degradation in aerobic sandy soil

    International Nuclear Information System (INIS)

    Elazhari-Ali, Abdulmagid; Singh, Arvind K.; Davenport, Russell J.; Head, Ian M.; Werner, David

    2013-01-01

    We tested the hypothesis that the biodegradation of volatile petroleum hydrocarbons (VPHs) in aerobic sandy soil is affected by the blending with 10 percent ethanol (E10) or 20 percent biodiesel (B20). When inorganic nutrients were scarce, competition between biofuel and VPH degraders temporarily slowed monoaromatic hydrocarbon degradation. Ethanol had a bigger impact than biodiesel, reflecting the relative ease of ethanol compared to methyl ester biodegradation. Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes revealed that each fuel mixture selected for a distinct bacterial community, each dominated by Pseudomonas spp. Despite lasting impacts on soil bacterial ecology, the overall effects on VHP biodegradation were minor, and average biomass yields were comparable between fuel types, ranging from 0.40 ± 0.16 to 0.51 ± 0.22 g of biomass carbon per gram of fuel carbon degraded. Inorganic nutrient availability had a greater impact on petroleum hydrocarbon biodegradation than fuel composition. Highlights: ► The effect of 10% ethanol or 20% biodiesel on the biodegradability of volatile petroleum hydrocarbons in soil was investigated. ► Competition for scarce inorganic nutrients between biofuel and VPH degraders slowed monoaromatic hydrocarbon degradation. ► Biofuel effects were transitional. ► Each fuel selected for a distinct predominant bacterial community. ► All bacterial communities were dominated by Pseudomonas spp. - Blending of petroleum with ethanol or biodiesel changes the fuel degrading soil bacterial community structure, but the long-term effects on fuel biodegradability are minor.

  11. Putative bacterial interactions from metagenomic knowledge with an integrative systems ecology approach.

    Science.gov (United States)

    Bordron, Philippe; Latorre, Mauricio; Cortés, Maria-Paz; González, Mauricio; Thiele, Sven; Siegel, Anne; Maass, Alejandro; Eveillard, Damien

    2016-02-01

    Following the trend of studies that investigate microbial ecosystems using different metagenomic techniques, we propose a new integrative systems ecology approach that aims to decipher functional roles within a consortium through the integration of genomic and metabolic knowledge at genome scale. For the sake of application, using public genomes of five bacterial strains involved in copper bioleaching: Acidiphilium cryptum, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferriphilum, and Sulfobacillus thermosulfidooxidans, we first reconstructed a global metabolic network. Next, using a parsimony assumption, we deciphered sets of genes, called Sets from Genome Segments (SGS), that (1) are close on their respective genomes, (2) take an active part in metabolic pathways and (3) whose associated metabolic reactions are also closely connected within metabolic networks. Overall, this SGS paradigm depicts genomic functional units that emphasize respective roles of bacterial strains to catalyze metabolic pathways and environmental processes. Our analysis suggested that only few functional metabolic genes are horizontally transferred within the consortium and that no single bacterial strain can accomplish by itself the whole copper bioleaching. The use of SGS pinpoints a functional compartmentalization among the investigated species and exhibits putative bacterial interactions necessary for promoting these pathways. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. Revisiting life strategy concepts in environmental microbial ecology.

    Science.gov (United States)

    Ho, Adrian; Di Lonardo, D Paolo; Bodelier, Paul L E

    2017-03-01

    Microorganisms are physiologically diverse, possessing disparate genomic features and mechanisms for adaptation (functional traits), which reflect on their associated life strategies and determine at least to some extent their prevalence and distribution in the environment. Unlike animals and plants, there is an unprecedented diversity and intractable metabolic versatility among bacteria, making classification or grouping these microorganisms based on their functional traits as has been done in animal and plant ecology challenging. Nevertheless, based on representative pure cultures, microbial traits distinguishing different life strategies had been proposed, and had been the focus of previous reviews. In the environment, however, the vast majority of naturally occurring microorganisms have yet to be isolated, restricting the association of life strategies to broad phylogenetic groups and/or physiological characteristics. Here, we reviewed the literature to determine how microbial life strategy concepts (i.e. copio- and oligotrophic strategists, and competitor-stress tolerator-ruderals framework) are applied in complex microbial communities. Because of the scarcity of direct empirical evidence elucidating the associated life strategies in complex communities, we rely heavily on observational studies determining the response of microorganisms to (a)biotic cues (e.g. resource availability) to infer microbial life strategies. Although our focus is on the life strategies of bacteria, parallels were drawn from the fungal community. Our literature search showed inconsistency in the community response of proposed copiotrophic- and oligotrophic-associated microorganisms (phyla level) to changing environmental conditions. This suggests that tracking microorganisms at finer phylogenetic and taxonomic resolution (e.g. family level or lower) may be more effective to capture changes in community response and/or that edaphic factors exert a stronger effect in community response

  13. Bacterial Diversity and Nitrogen Utilization Strategies in the Upper Layer of the Northwestern Pacific Ocean.

    Science.gov (United States)

    Li, Yuan-Yuan; Chen, Xiao-Huang; Xie, Zhang-Xian; Li, Dong-Xu; Wu, Peng-Fei; Kong, Ling-Fen; Lin, Lin; Kao, Shuh-Ji; Wang, Da-Zhi

    2018-01-01

    Nitrogen (N) is a primary limiting nutrient for bacterial growth and productivity in the ocean. To better understand bacterial community and their N utilization strategy in different N regimes of the ocean, we examined bacterial diversity, diazotrophic diversity, and N utilization gene expressions in the northwestern Pacific Ocean (NWPO) using a combination of high-throughput sequencing and real-time qPCR methods. 521 and 204 different operational taxonomic units (OTUs) were identified in the 16s rRNA and nifH libraries from nine surface samples. Of the 16s rRNA gene OTUs, 11.9% were observed in all samples while 3.5 and 15.9% were detected only in N-sufficient and N-deficient samples. Proteobacteria, Cyanobacteria and Bacteroidetes dominated the bacterial community. Prochlorococcus and Pseudoalteromonas were the most abundant at the genus level in N-deficient regimes, while SAR86, Synechococcus and SAR92 were predominant in the Kuroshio-Oyashio confluence region. The distribution of the nifH gene presented great divergence among sampling stations: Cyanobacterium_UCYN-A dominated the N-deficient stations, while clusters related to the Alpha-, Beta- , and Gamma-Proteobacteria were abundant in other stations. Temperature was the main factor that determined bacterial community structure and diversity while concentration of NO X -N was significantly correlated with structure and distribution of N 2 -fixing microorganisms. Expression of the ammonium transporter was much higher than that of urea transporter subunit A ( urtA ) and ferredoxin-nitrate reductase , while urtA had an increased expression in N-deficient surface water. The predicted ammonium transporter and ammonium assimilation enzymes were most abundant in surface samples while urease and nitrogenase were more abundant in the N-deficient regions. These findings underscore the fact that marine bacteria have evolved diverse N utilization strategies to adapt to different N habitats, and that urea metabolism is of

  14. Bacterial Diversity and Nitrogen Utilization Strategies in the Upper Layer of the Northwestern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Yuan-Yuan Li

    2018-04-01

    Full Text Available Nitrogen (N is a primary limiting nutrient for bacterial growth and productivity in the ocean. To better understand bacterial community and their N utilization strategy in different N regimes of the ocean, we examined bacterial diversity, diazotrophic diversity, and N utilization gene expressions in the northwestern Pacific Ocean (NWPO using a combination of high-throughput sequencing and real-time qPCR methods. 521 and 204 different operational taxonomic units (OTUs were identified in the 16s rRNA and nifH libraries from nine surface samples. Of the 16s rRNA gene OTUs, 11.9% were observed in all samples while 3.5 and 15.9% were detected only in N-sufficient and N-deficient samples. Proteobacteria, Cyanobacteria and Bacteroidetes dominated the bacterial community. Prochlorococcus and Pseudoalteromonas were the most abundant at the genus level in N-deficient regimes, while SAR86, Synechococcus and SAR92 were predominant in the Kuroshio-Oyashio confluence region. The distribution of the nifH gene presented great divergence among sampling stations: Cyanobacterium_UCYN-A dominated the N-deficient stations, while clusters related to the Alpha-, Beta-, and Gamma-Proteobacteria were abundant in other stations. Temperature was the main factor that determined bacterial community structure and diversity while concentration of NOX-N was significantly correlated with structure and distribution of N2-fixing microorganisms. Expression of the ammonium transporter was much higher than that of urea transporter subunit A (urtA and ferredoxin-nitrate reductase, while urtA had an increased expression in N-deficient surface water. The predicted ammonium transporter and ammonium assimilation enzymes were most abundant in surface samples while urease and nitrogenase were more abundant in the N-deficient regions. These findings underscore the fact that marine bacteria have evolved diverse N utilization strategies to adapt to different N habitats, and that urea

  15. Ecological mechanisms underlying soil bacterial responses to rainfall along a steep natural precipitation gradient.

    Science.gov (United States)

    Waring, Bonnie; Hawkes, Christine V

    2018-02-01

    Changes in the structure and function of soil microbial communities can drive substantial ecosystem feedbacks to altered precipitation. However, the ecological mechanisms underlying community responses to environmental change are not well understood. We used an 18-month soil reciprocal transplant experiment along a steep precipitation gradient to quantify how changes in rainfall affected bacterial community structure. We also conducted an enhanced dispersal treatment to ask whether higher immigration rates of taxa from the surrounding environment would accelerate community responses to climate change. Finally, we addressed how the composition of soil bacteria communities was related to the functional response of soil respiration to moisture in these treatments. Bacterial community structure (OTU abundance) and function (respiration rates) changed little in response to manipulation of either rainfall environment or dispersal rates. Although most bacteria were ecological generalists, a subset of specialist taxa, over 40% of which were Actinobacteria, tended to be more abundant in the rainfall environment that matched their original conditions. Bacteria community composition was an important predictor of the respiration response to moisture. Thus, the high compositional resistance of microbial communities dictated respiration responses to altered rainfall in this system.

  16. Mini-review: Strategies for Variation and Evolution of Bacterial Antigens

    Science.gov (United States)

    Foley, Janet

    2015-01-01

    Across the eubacteria, antigenic variation has emerged as a strategy to evade host immunity. However, phenotypic variation in some of these antigens also allows the bacteria to exploit variable host niches as well. The specific mechanisms are not shared-derived characters although there is considerable convergent evolution and numerous commonalities reflecting considerations of natural selection and biochemical restraints. Unlike in viruses, mechanisms of antigenic variation in most bacteria involve larger DNA movement such as gene conversion or DNA rearrangement, although some antigens vary due to point mutations or modified transcriptional regulation. The convergent evolution that promotes antigenic variation integrates various evolutionary forces: these include mutations underlying variant production; drift which could remove alleles especially early in infection or during life history phases in arthropod vectors (when the bacterial population size goes through a bottleneck); selection not only for any particular variant but also for the mechanism for the production of variants (i.e., selection for mutability); and overcoming negative selection against variant production. This review highlights the complexities of drivers of antigenic variation, in particular extending evaluation beyond the commonly cited theory of immune evasion. A deeper understanding of the diversity of purpose and mechanisms of antigenic variation in bacteria will contribute to greater insight into bacterial pathogenesis, ecology and coevolution with hosts. PMID:26288700

  17. Ecological advantages of partial migration as a conditional strategy.

    Science.gov (United States)

    Vélez-Espino, Luis A; McLaughlin, Robert L; Robillard, Melissa

    2013-05-01

    Partial migration is a widespread phenomenon characterized by migrant and resident forms from the same population. In phenotypically plastic taxa with indeterminate growth, resident and migrant ecophenotypes can differ in size and life history traits in ways expected to maximize fitness in the different habitats they exploit. Studies of partial migration in different taxa have advocated either density-dependence or environmental stochasticity as explanations for partial migration. We used a demographic approach for a virtual Brook Trout population to demonstrate the ecological consequences of partial migration under interacting density dependence and environmental stochasticity. The maintenance of partial migration as a conditional strategy in species/populations where resident and migrant forms exhibit life history asymmetries provides ecological advantages. We show that density-dependent migration is expected to increase population fitness under constant environmental conditions or low environmental variation, but decreases population fitness under high environmental variation. These conditions favor intermediate levels of migration as an advantageous tactic. However, there are threshold rates of return migration below which partial migration is no longer a viable tactic. Our modeling approach also allowed the exploration of the distribution of the population by life stage and habitat in response to the strength of density dependence, costs of migration, and return rates, and demonstrated the importance of the conservation of ecophenotypes in partially migratory populations. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Differentiation of bacterial feeding nematodes in soil ecological studies by means of arbitrarily primed PCR

    Science.gov (United States)

    Van Der Knaap, Esther; Rodriguez, Russell J.; Freckman, Diana W.

    1993-01-01

    Arbitrarily-primed polymerase chain reaction (ap-PCR) was used to differentiate closely related bacterial-feeding nematodes of the genera: Caenorhabditis, Acrobeloides, Cephalobus and Zeldia. Average percentage similarity of bands generated by ap-PCR with seven different primers between 14 isolates of Caenorhabditis elegans was ⪢ 90%, whereas between C. elegans, C. briggsae and C. remanei similarity was nematode populations were also obtained from ap-PCR analysis of single worms. Due to the difficulty of identification of soil nematodes, the ap-PCR offers potential as a rapid and reliable technique to assess biodiversity. Ap-PCR will make it feasible, for the first time, to study the ecological interactions of unique nematode genotypes in soil habitats.

  19. Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

  20. [Ecological treatment of bacterial vaginosis and vaginitis with Bio-three].

    Science.gov (United States)

    Chimura, T

    1998-12-01

    Ecological treatment of bacterial vaginosis and vaginitis with a Bio-three was studied, and the following results were obtained. 1. A total of 16 women with bacterial vaginosis and vaginitis were treated with intravaginal application of 2 g of Bio-three (E. faecalis T-110, C. butyricum TO-A, B. mesentericus TO-A, pH 6.9 +/- 0.3). The effect of the treatment was evaluated 3 days after administration by monitoring the vaginal discharge and bacteriological assessment. 2. The clinical improvement was evaluated and the decreases of vaginal discharge and vaginal redness were significant and vaginal pH was lowered significantly (5.29 +/- 0.24 vs. 4.31 +/- 0.37, p vaginal discharge 35 strains of bacteria were detected, but 3 days after administration, 16/30 strains of Gram-positive bacteria, and 2 strains of Gram-negative bacteria disappeared. As for the overall bacteriological effects, 7/16 cases were eradicated, 1 case was partly eradicated, 6 cases were replaced. These findings indicated that the Bio-three therapy was effective in both clinical and bacteriological responses.

  1. Molecular mechanisms underlying the emergence of bacterial pathogens: an ecological perspective.

    Science.gov (United States)

    Bartoli, Claudia; Roux, Fabrice; Lamichhane, Jay Ram

    2016-02-01

    The rapid emergence of new bacterial diseases negatively affects both human health and agricultural productivity. Although the molecular mechanisms underlying these disease emergences are shared between human- and plant-pathogenic bacteria, not much effort has been made to date to understand disease emergences caused by plant-pathogenic bacteria. In particular, there is a paucity of information in the literature on the role of environmental habitats in which plant-pathogenic bacteria evolve and on the stress factors to which these microbes are unceasingly exposed. In this microreview, we focus on three molecular mechanisms underlying pathogenicity in bacteria, namely mutations, genomic rearrangements and the acquisition of new DNA sequences through horizontal gene transfer (HGT). We briefly discuss the role of these mechanisms in bacterial disease emergence and elucidate how the environment can influence the occurrence and regulation of these molecular mechanisms by directly impacting disease emergence. The understanding of such molecular evolutionary mechanisms and their environmental drivers will represent an important step towards predicting bacterial disease emergence and developing sustainable management strategies for crops. © 2015 BSPP AND JOHN WILEY & SONS LTD.

  2. Ecological drift and local exposures drive enteric bacterial community differences within species of Galápagos iguanas.

    Science.gov (United States)

    Lankau, Emily W; Hong, Pei-Ying; Mackie, Roderick I

    2012-04-01

    Diet strongly influences the intestinal microbial communities through species sorting. Alternatively, these communicates may differ because of chance variation in local microbial exposures or species losses among allopatric host populations (i.e. ecological drift). We investigated how these forces shape enteric communities of Galápagos marine and land iguanas. Geographically proximate populations shared more similar communities within a host ecotype, suggesting a role for ecological drift during host colonization of the islands. Additionally, evidence of taxa sharing between proximate heterospecific host populations suggests that contemporary local exposures also influence the gut community assembly. While selective forces such as host-bacterial interactions or dietary differences are dominant drivers of intestinal community differences among hosts, historical and contemporary processes of ecological drift may lead to differences in bacterial composition within a host species. Whether such differences in community structure translate into geographic variation in benefits derived from these intimate microbial communities remains to be explored. © 2012 Blackwell Publishing Ltd.

  3. Patterns of bacteria-host associations suggest different ecological strategies between two reef building cold-water coral species

    Science.gov (United States)

    Meistertzheim, Anne.-Leila; Lartaud, Franck; Arnaud-Haond, Sophie; Kalenitchenko, Dimitri; Bessalam, Manon; Le Bris, Nadine; Galand, Pierre E.

    2016-08-01

    Cold-water corals (CWC) are main ecosystem engineers of the deep sea, and their reefs constitute hot-spots of biodiversity. However, their ecology remains poorly understood, particularly, the nature of the holobiont formed by corals with their associated bacterial communities. Here, we analyzed Madrepora oculata and Lophelia pertusa samples, collected from one location in a Mediterranean canyon in two different seasons (autumn and spring), in order to test for species specificity and temporal stability of the host-bacteria associations. The 16S rRNA sequencing revealed host-specific patterns of bacterial communities associated with L. pertusa and M. oculata, both in terms of community composition and diversity. All analyzed M. oculata polyps exhibited temporally and spatially similar bacterial communities dominated by haplotypes homologous to the known cnidarians-associated genus Endozoicomonas. In contrast, the bacterial communities associated with L. pertusa varied among polyps from the same colony, as well as among distinct colonies and between seasons. While the resilient consortium formed by M. oculata and its bacterial community fit the definition of holobiont, the versatility of the L. pertusa microbiome suggests that this association is more influenced by the environmental conditions or nutritional status. Our results thus highlight distinct host/microbes association strategies for these two closely related Scleractinians sharing the same habitat, suggesting distinct sensitivity to environmental change.

  4. Globalization and sustainable development: a political ecology strategy to realize ecological justice

    OpenAIRE

    Byrne, John; Glover, Leigh; Alrøe, Hugo Fjelsted

    2006-01-01

    Organic agriculture is, like mainstream agriculture, faced with the challenges of globalization and sustainable development. Ecological justice, the fair distribution of livelihoods and environments, has emerged as a key concept in efforts, on the one hand, to resist negative consequences of globalization and ecological modernization and, on the other to propose new agenda and institutional arrangements. This chapter investigates the role that ecological justice as a political ecology strateg...

  5. Towards Defining the Ecological Niches of Novel Coastal Gulf of Mexico Bacterial Isolates

    Science.gov (United States)

    Henson, M. W.; Thrash, C.; Nall, E.

    2016-02-01

    The study of microbial contributions to biogeochemistry is critical to understanding the cycles of fundamental compounds and gain predictive capabilities in a changing environment. Such study requires observation of microbial communities and genetics in nature, coupled with experimental testing of hypotheses both in situ and in laboratory settings. This study combines dilution-to-extinction based high-throughput culturing (HTC) with cultivation-independent and geochemical measurements to define potential ecological niches of novel bacterial isolates from the coastal northern Gulf of Mexico (cnGOM). Here we report findings from the first of a three-year project. In total, 43 cultures from seven HTC experiments were capable of being repeatedly transferred. Sanger sequencing of the 16S rRNA gene identified these isolates as belonging to the phyla Gammaproteobacteria, Alphaproteobacteria, Actinobacteria, and Betaproteobacteria. Eight are being genome sequenced, with two selected for further physiological characterization due to their phylogenic novelty and potential ecological significance. Strain LSUCC101 likely represents a novel family of Gammaproteobacteria (best blast hit to a cultured representative showed 91% sequence identity) and strain LSUCC96 belongs to the OM252 clade, with the Hawaiian isolate HIMB30 as its closest relative. Both are small (0.3-0.5 µm) cocci. The environmental importance of both LSUCC101 and LSUCC96 was illustrated by their presence within the top 30 OTU0.03 of cnGOM 16S rRNA gene datasets as well as within clone libraries from coastal regions around the world. Ongoing work is determining growth efficiencies, substrate utilization profiles, and metabolic potential to elucidate the roles of these organisms in the cnGOM. Comparative genomics will examine the evolutionary divergence of these organisms from their closest neighbors, and metagenomic recruitment to genomes will help identify strain-based variation from different coastal regions.

  6. Plant-insect interactions under bacterial influence: ecological implications and underlying mechanisms.

    Science.gov (United States)

    Sugio, Akiko; Dubreuil, Géraldine; Giron, David; Simon, Jean-Christophe

    2015-02-01

    Plants and insects have been co-existing for more than 400 million years, leading to intimate and complex relationships. Throughout their own evolutionary history, plants and insects have also established intricate and very diverse relationships with microbial associates. Studies in recent years have revealed plant- or insect-associated microbes to be instrumental in plant-insect interactions, with important implications for plant defences and plant utilization by insects. Microbial communities associated with plants are rich in diversity, and their structure greatly differs between below- and above-ground levels. Microbial communities associated with insect herbivores generally present a lower diversity and can reside in different body parts of their hosts including bacteriocytes, haemolymph, gut, and salivary glands. Acquisition of microbial communities by vertical or horizontal transmission and possible genetic exchanges through lateral transfer could strongly impact on the host insect or plant fitness by conferring adaptations to new habitats. Recent developments in sequencing technologies and molecular tools have dramatically enhanced opportunities to characterize the microbial diversity associated with plants and insects and have unveiled some of the mechanisms by which symbionts modulate plant-insect interactions. Here, we focus on the diversity and ecological consequences of bacterial communities associated with plants and herbivorous insects. We also highlight the known mechanisms by which these microbes interfere with plant-insect interactions. Revealing such mechanisms in model systems under controlled environments but also in more natural ecological settings will help us to understand the evolution of complex multitrophic interactions in which plants, herbivorous insects, and micro-organisms are inserted. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions

  7. Ecological Footprint in relation to Climate Change Strategy in Cities

    Science.gov (United States)

    Belčáková, Ingrid; Diviaková, Andrea; Belaňová, Eliška

    2017-10-01

    Ecological footprint determines how much natural resources are consumed by an individual, city, region, state or all inhabitants of our planet in order to ensure their requirements and needs. It includes all activities, from food consumption, housing, transport to waste produced and allows us to compare particular activities and their impacts on the environment and natural resources. Ecological footprint is important issue for making sustainable development concept more popular using simplifications, which provide the public with basic information on situation on our planet. Today we know calculations of global (worldwide), national and local ecological footprints. During our research in cities, we were concentrated on calculation of city’s ecological footprint. The article tries to outline theoretical and assumptions and practical results of climate change consequences in cities of Bratislava and Nitra (Slovakia), to describe potential of mitigating adverse impacts of climate change and to provide information for general and professional public on theoretical assumptions in calculating ecological footprint. The intention is to present innovation of ecological footprint calculation, taking into consideration ecological stability of a city (with a specific focus on micro-climate functions of green areas). Present possibilities to reduce ecological footprint are presented.

  8. Quorum sensing is a language of chemical signals and plays an ecological role in algal-bacterial interactions.

    Science.gov (United States)

    Zhou, Jin; Lyu, Yihua; Richlen, Mindy; Anderson, Donald M; Cai, Zhonghua

    2016-01-01

    Algae are ubiquitous in the marine environment, and the ways in which they interact with bacteria are of particular interest in marine ecology field. The interactions between primary producers and bacteria impact the physiology of both partners, alter the chemistry of their environment, and shape microbial diversity. Although algal-bacterial interactions are well known and studied, information regarding the chemical-ecological role of this relationship remains limited, particularly with respect to quorum sensing (QS), which is a system of stimuli and response correlated to population density. In the microbial biosphere, QS is pivotal in driving community structure and regulating behavioral ecology, including biofilm formation, virulence, antibiotic resistance, swarming motility, and secondary metabolite production. Many marine habitats, such as the phycosphere, harbour diverse populations of microorganisms and various signal languages (such as QS-based autoinducers). QS-mediated interactions widely influence algal-bacterial symbiotic relationships, which in turn determine community organization, population structure, and ecosystem functioning. Understanding infochemicals-mediated ecological processes may shed light on the symbiotic interactions between algae host and associated microbes. In this review, we summarize current achievements about how QS modulates microbial behavior, affects symbiotic relationships, and regulates phytoplankton chemical ecological processes. Additionally, we present an overview of QS-modulated co-evolutionary relationships between algae and bacterioplankton, and consider the potential applications and future perspectives of QS.

  9. National strategy of ecological transition towards sustainable development 2015-2020

    International Nuclear Information System (INIS)

    2014-05-01

    In 2015, the energy transition law for green growth is creating a momentum which removes obstacles, boosts initiatives and enables everyone to act. All stakeholders, local authorities, NGO's, businesses and citizens are gradually building a new social model that combines economic, ecological and human progress. Building on that momentum, the national strategy of ecological transition towards sustainable development (SNTEDD) 2015-2020 replaces the national sustainable development strategy 2010-2013 by setting us on a new path to sustainable development. The national strategy of ecological transition towards sustainable development ensures the consistency of public policies and facilitates people's ownership

  10. Current and past strategies for bacterial culture in clinical microbiology.

    Science.gov (United States)

    Lagier, Jean-Christophe; Edouard, Sophie; Pagnier, Isabelle; Mediannikov, Oleg; Drancourt, Michel; Raoult, Didier

    2015-01-01

    A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia. The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Ecological models for regulatory risk assessments of pesticides: Developing a strategy for the future.

    NARCIS (Netherlands)

    Thorbek, P.; Forbes, V.; Heimbach, F.; Hommen, U.; Thulke, H.H.; Brink, van den P.J.

    2010-01-01

    Ecological Models for Regulatory Risk Assessments of Pesticides: Developing a Strategy for the Future provides a coherent, science-based view on ecological modeling for regulatory risk assessments. It discusses the benefits of modeling in the context of registrations, identifies the obstacles that

  12. Comparing spatially explicit ecological and social values for natural areas to identify effective conservation strategies.

    Science.gov (United States)

    Bryan, Brett Anthony; Raymond, Christopher Mark; Crossman, Neville David; King, Darran

    2011-02-01

    Consideration of the social values people assign to relatively undisturbed native ecosystems is critical for the success of science-based conservation plans. We used an interview process to identify and map social values assigned to 31 ecosystem services provided by natural areas in an agricultural landscape in southern Australia. We then modeled the spatial distribution of 12 components of ecological value commonly used in setting spatial conservation priorities. We used the analytical hierarchy process to weight these components and used multiattribute utility theory to combine them into a single spatial layer of ecological value. Social values assigned to natural areas were negatively correlated with ecological values overall, but were positively correlated with some components of ecological value. In terms of the spatial distribution of values, people valued protected areas, whereas those natural areas underrepresented in the reserve system were of higher ecological value. The habitats of threatened animal species were assigned both high ecological value and high social value. Only small areas were assigned both high ecological value and high social value in the study area, whereas large areas of high ecological value were of low social value, and vice versa. We used the assigned ecological and social values to identify different conservation strategies (e.g., information sharing, community engagement, incentive payments) that may be effective for specific areas. We suggest that consideration of both ecological and social values in selection of conservation strategies can enhance the success of science-based conservation planning. ©2010 Society for Conservation Biology.

  13. Biofilm bacterial communities in urban drinking water distribution systems transporting waters with different purification strategies.

    Science.gov (United States)

    Wu, Huiting; Zhang, Jingxu; Mi, Zilong; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-02-01

    Biofilm formation in drinking water distribution systems (DWDS) has many adverse consequences. Knowledge of microbial community structure of DWDS biofilm can aid in the design of an effective control strategy. However, biofilm bacterial community in real DWDS and the impact of drinking water purification strategy remain unclear. The present study investigated the composition and diversity of biofilm bacterial community in real DWDSs transporting waters with different purification strategies (conventional treatment and integrated treatment). High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the diversity and structure of biofilm bacterial community in real DWDS. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Nitrospirae, and Cyanobacteria were the major components of biofilm bacterial community. Proteobacteria (mainly Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria) predominated in each DWDS biofilm, but the compositions of the dominant proteobacterial classes and genera and their proportions varied among biofilm samples. Drinking water purification strategy could shape DWDS biofilm bacterial community. Moreover, Pearson's correlation analysis indicated that Actinobacteria was positively correlated with the levels of total alkalinity and dissolved organic carbon in tap water, while Firmicutes had a significant positive correlation with nitrite nitrogen.

  14. Bacterial Biofilms and Catheters: A Key to Understanding Bacterial Strategies in Catheter-Associated Urinary Tract Infection

    Directory of Open Access Journals (Sweden)

    J Curtis Nickel

    1992-01-01

    Full Text Available Despite major technological improvements in catheter drainage systems, the indwelling Foley catheter remains the most common cause of nosocomial infection in medical practice. By approaching this common complicated urinary tract infection from the perspective of the biofilm strategy bacteria appear to use to overcome obstacles to produce bacteriuria, one appreciates a new understanding of these infections. An adherent biofilm of bacteria in their secretory products ascends the luminal and external surface of the catheter and drainage system from a contaminated drainage spigot or urethral meatus into the bladder. If the intraluminal route of bacterial ascent is delayed by strict sterile closed drainage or addition of internal modifications to the system, the extraluminal or urethral route assumes greater importance in the development of bacteriuria, but takes significantly longer. Bacterial growth within these thick coherent biofilms confers a large measure of relative resistance to antibiotics even though the individual bacterium remains sensitive, thus accounting for the failure of antibiotic therapy. With disruption of the protective mucous layer of the bladder by mechanical irritation, the bacteria colonizing the catheter can adhere to the bladder’s mucosal surface and cause infection. An appreciation of the role of bacterial biofilms in these infections should suggest future directions for research that may ultimately reduce the risk of catheter-associated infection.

  15. Conventional and nonconventional strategies for controlling bacterial contamination in fuel ethanol fermentations.

    Science.gov (United States)

    Ceccato-Antonini, Sandra Regina

    2018-05-25

    Ethanol bio-production in Brazil has some unique characteristics that inevitably lead to bacterial contamination, which results in the production of organic acids and biofilms and flocculation that impair the fermentation yield by affecting yeast viability and diverting sugars to metabolites other than ethanol. The ethanol-producing units commonly give an acid treatment to the cells after each fermentative cycle to decrease the bacterial number, which is not always effective. An alternative strategy must be employed to avoid bacterial multiplication but must be compatible with economic, health and environmental aspects. This review analyzes the issue of bacterial contamination in sugarcane-based fuel ethanol fermentation, and the potential strategies that may be utilized to control bacterial growth besides acid treatment and antibiotics. We have emphasized the efficiency and suitability of chemical products other than acids and those derived from natural sources in industrial conditions. In addition, we have also presented bacteriocins, bacteriophages, and beneficial bacteria as non-conventional antimicrobial agents to mitigate bacterial contamination in the bioethanol industry.

  16. Improved bacteriophage genome data is necessary for integrating viral and bacterial ecology.

    Science.gov (United States)

    Bibby, Kyle

    2014-02-01

    The recent rise in "omics"-enabled approaches has lead to improved understanding in many areas of microbial ecology. However, despite the importance that viruses play in a broad microbial ecology context, viral ecology remains largely not integrated into high-throughput microbial ecology studies. A fundamental hindrance to the integration of viral ecology into omics-enabled microbial ecology studies is the lack of suitable reference bacteriophage genomes in reference databases-currently, only 0.001% of bacteriophage diversity is represented in genome sequence databases. This commentary serves to highlight this issue and to promote bacteriophage genome sequencing as a valuable scientific undertaking to both better understand bacteriophage diversity and move towards a more holistic view of microbial ecology.

  17. Plasticity in early immune evasion strategies of a bacterial pathogen.

    Science.gov (United States)

    Bernard, Quentin; Smith, Alexis A; Yang, Xiuli; Koci, Juraj; Foor, Shelby D; Cramer, Sarah D; Zhuang, Xuran; Dwyer, Jennifer E; Lin, Yi-Pin; Mongodin, Emmanuel F; Marques, Adriana; Leong, John M; Anguita, Juan; Pal, Utpal

    2018-04-17

    Borrelia burgdorferi is one of the few extracellular pathogens capable of establishing persistent infection in mammals. The mechanisms that sustain long-term survival of this bacterium are largely unknown. Here we report a unique innate immune evasion strategy of B. burgdorferi , orchestrated by a surface protein annotated as BBA57, through its modulation of multiple spirochete virulent determinants. BBA57 function is critical for early infection but largely redundant for later stages of spirochetal persistence, either in mammals or in ticks. The protein influences host IFN responses as well as suppresses multiple host microbicidal activities involving serum complement, neutrophils, and antimicrobial peptides. We also discovered a remarkable plasticity in BBA57-mediated spirochete immune evasion strategy because its loss, although resulting in near clearance of pathogens at the inoculum site, triggers nonheritable adaptive changes that exclude detectable nucleotide alterations in the genome but incorporate transcriptional reprograming events. Understanding the malleability in spirochetal immune evasion mechanisms that ensures their host persistence is critical for the development of novel therapeutic and preventive approaches to combat long-term infections like Lyme borreliosis.

  18. METHODOLOGICAL INSTRUMENTS FOR FORMING THE MARKETING STRATEGY OF AGRICULTURAL PRODUCTION ECOLOGIZATION

    Directory of Open Access Journals (Sweden)

    Mariya Bagorka

    2017-09-01

    Full Text Available The purpose of the article is the investigation of the nature, objectives, and strategic categories of ecologization marketing strategy, development of algorithm of this strategy and determination of environmental, economic, and ecological instruments of implementation of this strategy in the agricultural sector. Methodology. The basis of the formation of a marketing strategy for the ecologization of agrarian production is the systematic approach, which is based on the existence of implementation mechanisms that ensure system consistency, its purposefulness; interdependence; and complexity of its elements, which determines the integrity of the system; all tasks that execute individual elements of the system are interconnected; system elements and their associated actions have a certain subordination that builds a hierarchy; the system changes under the influence of specific factors, which determines its dynamism; the ability of the system to adapt to the variability of the external environment, while not losing its own individuality. Methods for strategic analysis of macro- and micro-environment factors were used to form the marketing strategy of ecologization. This process involves an analytical evaluation of the parameters of the external and internal environment with the help of general scientific and applied methods of strategic analysis. Results. The article explored the ecologization strategy, presented its objectives in the field of agriculture, the basic categories of strategic directions and implementation of ecologization marketing strategies. An algorithm of environmental marketing strategies in agricultural production is developed, environmental, economic and environmental and economic tools to implement them are determined. Practical implications. It is determined that marketing strategy of ecologization of agrarian production is a strategy of innovative development that can solve problems of economic growth, an increase of

  19. Bacterial Quorum Sensing Stabilizes Cooperation by Optimizing Growth Strategies.

    Science.gov (United States)

    Bruger, Eric L; Waters, Christopher M

    2016-11-15

    Communication has been suggested as a mechanism to stabilize cooperation. In bacteria, chemical communication, termed quorum sensing (QS), has been hypothesized to fill this role, and extracellular public goods are often induced by QS at high cell densities. Here we show, with the bacterium Vibrio harveyi, that QS provides strong resistance against invasion of a QS defector strain by maximizing the cellular growth rate at low cell densities while achieving maximum productivity through protease upregulation at high cell densities. In contrast, QS mutants that act as defectors or unconditional cooperators maximize either the growth rate or the growth yield, respectively, and thus are less fit than the wild-type QS strain. Our findings provide experimental evidence that regulation mediated by microbial communication can optimize growth strategies and stabilize cooperative phenotypes by preventing defector invasion, even under well-mixed conditions. This effect is due to a combination of responsiveness to environmental conditions provided by QS, lowering of competitive costs when QS is not induced, and pleiotropic constraints imposed on defectors that do not perform QS. Cooperation is a fundamental problem for evolutionary biology to explain. Conditional participation through phenotypic plasticity driven by communication is a potential solution to this dilemma. Thus, among bacteria, QS has been proposed to be a proximate stabilizing mechanism for cooperative behaviors. Here, we empirically demonstrate that QS in V. harveyi prevents cheating and subsequent invasion by nonproducing defectors by maximizing the growth rate at low cell densities and the growth yield at high cell densities, whereas an unconditional cooperator is rapidly driven to extinction by defectors. Our findings provide experimental evidence that QS regulation prevents the invasion of cooperative populations by QS defectors even under unstructured conditions, and they strongly support the role of

  20. Effects of ecological engineered oxygenation on the bacterial community structure in an anoxic fjord in western Sweden

    DEFF Research Database (Denmark)

    Forth, M.; Liljebladh, B.; Stigebrandt, A.

    2015-01-01

    Oxygen-depleted bodies of water are becoming increasingly common in marine ecosystems. Solutions to reverse this trend are needed and under development, for example, by the Baltic deep-water OXygenation (BOX) project. In the framework of this project, the Swedish Byfjord was chosen for a pilot...... in the lower water column and the benthic zone up to 110 mumol l(-1).We used molecular ecologic methods to study changes in bacterial community structure in response to the oxygenation in the Byfjord. Water column samples from before, during and after the oxygenation as well as from two nearby control fjords...

  1. Revisiting life strategy concepts in environmental microbial ecology

    NARCIS (Netherlands)

    Ho, A.; Di Lonardo, P.; Bodelier, P.L.E.

    2017-01-01

    Microorganisms are physiologically diverse, possessing disparate genomic features and mechanisms for adaptation (functional traits), which reflect on their associated life strategies and determine at least to some extent their prevalence and distribution in the environment. Unlike animals and

  2. A bacterial community-based index to assess the ecological status of estuarine and coastal environments

    KAUST Repository

    Aylagas, Eva

    2016-10-23

    Biotic indices for monitoring marine ecosystems are mostly based on the analysis of benthic macroinvertebrate communities. Due to their high sensitivity to pollution and fast response to environmental changes, bacterial assemblages could complement the information provided by benthic metazoan communities as indicators of human-induced impacts, but so far, this biological component has not been well explored for this purpose. Here we performed 16S rRNA gene amplicon sequencing to analyze the bacterial assemblage composition of 51 estuarine and coastal stations characterized by different environmental conditions and human-derived pressures. Using the relative abundance of putative indicator bacterial taxa, we developed a biotic index that is significantly correlated with a sediment quality index calculated on the basis of organic and inorganic compound concentrations. This new index based on bacterial assemblage composition can be a sensitive tool for providing a fast environmental assessment and allow a more comprehensive integrative ecosystem approach for environmental management. © 2016.

  3. A bacterial community-based index to assess the ecological status of estuarine and coastal environments

    KAUST Repository

    Aylagas, Eva; Borja, Á ngel; Tangherlini, Michael; Dell'Anno, Antonio; Corinaldesi, Cinzia; Michell, Craig; Irigoien, Xabier; Danovaro, Roberto; Rodrí guez-Ezpeleta, Naiara

    2016-01-01

    Biotic indices for monitoring marine ecosystems are mostly based on the analysis of benthic macroinvertebrate communities. Due to their high sensitivity to pollution and fast response to environmental changes, bacterial assemblages could complement

  4. Ecological fitness, genomic islands and bacterial pathogenicity: A Darwinian view of the evolution of microbes

    OpenAIRE

    Hacker, Jörg; Carniel, Elisabeth

    2001-01-01

    The compositions of bacterial genomes can be changed rapidly and dramatically through a variety of processes including horizontal gene transfer. This form of change is key to bacterial evolution, as it leads to ‘evolution in quantum leaps’. Horizontal gene transfer entails the incorporation of genetic elements transferred from another organism—perhaps in an earlier generation—directly into the genome, where they form ‘genomic islands’, i.e. blocks of DNA with signatures of mobile genetic elem...

  5. Do seedling functional groups reflect ecological strategies of woody plant species in Caatinga?

    Directory of Open Access Journals (Sweden)

    Tatiane Gomes Calaça Menezes

    2017-11-01

    Full Text Available ABSTRACT It is assumed that morphological traits of seedlings reflect different strategies in response to environmental conditions. The ecological significance of this has been widely documented in rainforests, where habitat structure and species interactions play an important role in community assembly. However, in seasonally dry ecosystems, where environmental filtering is expected to strongly influence community structure, this relationship is poorly understood. We investigated this relationship between functional groups of seedlings and life history traits and tested whether functional group predicts the ecological strategies employed by woody species to deal with the stressful conditions in seasonally dry ecosystems. Seedling functional groups, life history traits and traits that reflect ecological strategies for occupying seasonally dry environments were described for twenty-six plant species. Seedlings of species from the Caatinga vegetation exhibited a functional profile different from that observed in rainforests ecosystems. Phanerocotylar-epigeal seedlings were the most frequently observed groups, and had the largest range of ecological strategies related to dealing with seasonally dry environments, while phanerocotylar-hypogeal-reserve seedlings exhibited an increase in frequency with seasonality. We discuss these results in relation to those observed in other tropical forests and their ecological significance in seasonally dry environments.

  6. Effect of Dietary Protein Levels on Composition of Odorous Compounds and Bacterial Ecology in Pig Manure

    Directory of Open Access Journals (Sweden)

    Sungback Cho

    2015-09-01

    Full Text Available This study was performed to investigate the effect of different levels of dietary crude protein (CP on composition of odorous compounds and bacterial communities in pig manure. A total of 48 male pigs (average initial body weight 45 kg fed diets containing three levels of dietary CP (20%, 17.5%, and 15% and their slurry samples were collected from the pits under the floor every week for one month. Changes in composition of odorous compounds and bacterial communities were analyzed by gas chromatography and 454 FLX titanium pyrosequencing systems, respectively. Levels of phenols, indoles, short chain fatty acid and branched chain fatty acid were lowest (p<0.05 in CP 15% group among three CP levels. Relative abundance of Bacteroidetes phylum and bacterial genera including Leuconostoc, Bacillus, Atopostipes, Peptonphilus, Ruminococcaceae_uc, Bacteroides, and Pseudomonas was lower (p<0.05 in CP 15% than in CP 20% group. There was a positive correlation (p<0.05 between odorous compounds and bacterial genera: phenol, indole, iso-butyric acid, and iso-valeric acid with Atopostipes, p-cresol and skatole with Bacteroides, acetic acid and butyric acid with AM982595_g of Porphyromonadaceae family, and propionic acid with Tissierella. Taken together, administration of 15% CP showed less production of odorous compounds than 20% CP group and this result might be associated with the changes in bacterial communities especially whose roles in protein metabolism.

  7. An ecological solution in power development strategy: hydroelectric Power

    International Nuclear Information System (INIS)

    Ionescu, S.; Teodorescu, D.

    1994-01-01

    One of the fundamental criteria in establishing the power development strategy is represented by the environmental protection. Besides increasing the power efficiency for users, the hydro power stands for a handy alternative to generate thermal power. Comparatively, if hydro power is properly planed and developed, it could allow conservation of fossil fuel resources (as it makes use of a renewable resources) and avoids air and water pollution and in addition would lead to certain positive effects upon the natural and anthropic environment (flood routing, optimizes the power supply-demand relationship, and so on). By making use of the data available in the international specific literature and the information on the power development strategy in Romania the effects incurred by hydro power are both qualitatively and quantitatively emphasized as compared to alternative power generation by fossil fuel combustion. The proposal is made to adopt certain law regulations as well as a methodology to evaluate the general efficiency of various types of power generating devices suiting the particular conditions of Romania and taking into account the social cost as well as environmental effects. Hence a power development strategy could be undertaking at the national level provided it meets the requirements of both power system and environment protection. (Author)

  8. Frontiers for research on the ecology of plant-pathogenic bacteria: fundamentals for sustainability: Challenges in Bacterial Molecular Plant Pathology.

    Science.gov (United States)

    Morris, Cindy E; Barny, Marie-Anne; Berge, Odile; Kinkel, Linda L; Lacroix, Christelle

    2017-02-01

    Methods to ensure the health of crops owe their efficacy to the extent to which we understand the ecology and biology of environmental microorganisms and the conditions under which their interactions with plants lead to losses in crop quality or yield. However, in the pursuit of this knowledge, notions of the ecology of plant-pathogenic microorganisms have been reduced to a plant-centric and agro-centric focus. With increasing global change, i.e. changes that encompass not only climate, but also biodiversity, the geographical distribution of biomes, human demographic and socio-economic adaptations and land use, new plant health problems will emerge via a range of processes influenced by these changes. Hence, knowledge of the ecology of plant pathogens will play an increasingly important role in the anticipation and response to disease emergence. Here, we present our opinion on the major challenges facing the study of the ecology of plant-pathogenic bacteria. We argue that the discovery of markedly novel insights into the ecology of plant-pathogenic bacteria is most likely to happen within a framework of more extensive scales of space, time and biotic interactions than those that currently guide much of the research on these bacteria. This will set a context that is more propitious for the discovery of unsuspected drivers of the survival and diversification of plant-pathogenic bacteria and of the factors most critical for disease emergence, and will set the foundation for new approaches to the sustainable management of plant health. We describe the contextual background of, justification for and specific research questions with regard to the following challenges: Development of terminology to describe plant-bacterial relationships in terms of bacterial fitness. Definition of the full scope of the environments in which plant-pathogenic bacteria reside or survive. Delineation of pertinent phylogenetic contours of plant-pathogenic bacteria and naming of strains

  9. A review of current strategies to reduce intraoperative bacterial contamination of surgical wounds

    OpenAIRE

    Dohmen, Pascal M.; Konertz, Wolfgang

    2007-01-01

    Surgical site infections are a mean topic in cardiac surgery, leading to a prolonged hospitalization, and substantially increased morbidity and mortality. One source of pathogens is the endogenous flora of the patient?s skin, which can contaminate the surgical site. A number of preoperative skin care strategies are performed to reduce bacterial contamination like preoperative antiseptic showering, hair removal, antisepsis of the skin, adhesive barrier drapes, and antimicrobial prophylaxis. Fu...

  10. Analyzing ecological restoration strategies for water and soil conservation

    Science.gov (United States)

    Mota da Silva, Jonathan; Silva, Marx Leandro Naves; Guimarães, João Luis Bittencourt; Sousa Júnior, Wilson Cabral; Figueiredo, Ricardo de Oliveira; da Rocha, Humberto Ribeiro

    2018-01-01

    The choice of areas for nature conservation involves the attempt to maximize the benefits, whether by carrying out an economic activity or by the provision of Ecosystem Services. Studies are needed to improve the understanding of the effect of the extent and position along the watershed of restored areas on soil and water conservation. This study aimed to understand how different restoration strategies might reflect in soil conservation and sediment retention. Using InVEST tool, sediment transport was simulated in a small 12 km2 watershed (Posses River, in Southeast Brazil), where one of first Brazilian Payment for Ecosystem Services (PES) projects is being carried out, comparing different hypothetical restoration strategies. With 25% of restoration, sediment export decreased by 78% for riparian restoration, and 27% for the steepest slopes restoration. On the other hand, the decrease in soil loss was lower for riparian restoration, with a 16% decrease, while the steepest slopes restoration reduced it by 21%. This mismatch between the reduction of sediment export and soil loss was explained by the fact that forest not only reduces soil loss locally but also traps sediment arriving from the upper parts of the watershed. While the first mechanism is important to provide soil stability, decreasing the risk of landslip, and to maintain agricultural productivity, the second can improve water quality and decrease the risk of silting, with positive effects on the water reservoirs at the outlet of the watershed. This suggests that Riparian and the Steepest Slopes restoration strategies are complementary in the sense of preventing sediments from reaching the water bodies as well as protecting them at their origin (with the reduction of erosion), so it will be advisable to consider the two types of restoration. PMID:29425214

  11. Analyzing ecological restoration strategies for water and soil conservation.

    Science.gov (United States)

    Saad, Sandra Isay; Mota da Silva, Jonathan; Silva, Marx Leandro Naves; Guimarães, João Luis Bittencourt; Sousa Júnior, Wilson Cabral; Figueiredo, Ricardo de Oliveira; Rocha, Humberto Ribeiro da

    2018-01-01

    The choice of areas for nature conservation involves the attempt to maximize the benefits, whether by carrying out an economic activity or by the provision of Ecosystem Services. Studies are needed to improve the understanding of the effect of the extent and position along the watershed of restored areas on soil and water conservation. This study aimed to understand how different restoration strategies might reflect in soil conservation and sediment retention. Using InVEST tool, sediment transport was simulated in a small 12 km2 watershed (Posses River, in Southeast Brazil), where one of first Brazilian Payment for Ecosystem Services (PES) projects is being carried out, comparing different hypothetical restoration strategies. With 25% of restoration, sediment export decreased by 78% for riparian restoration, and 27% for the steepest slopes restoration. On the other hand, the decrease in soil loss was lower for riparian restoration, with a 16% decrease, while the steepest slopes restoration reduced it by 21%. This mismatch between the reduction of sediment export and soil loss was explained by the fact that forest not only reduces soil loss locally but also traps sediment arriving from the upper parts of the watershed. While the first mechanism is important to provide soil stability, decreasing the risk of landslip, and to maintain agricultural productivity, the second can improve water quality and decrease the risk of silting, with positive effects on the water reservoirs at the outlet of the watershed. This suggests that Riparian and the Steepest Slopes restoration strategies are complementary in the sense of preventing sediments from reaching the water bodies as well as protecting them at their origin (with the reduction of erosion), so it will be advisable to consider the two types of restoration.

  12. Analyzing ecological restoration strategies for water and soil conservation.

    Directory of Open Access Journals (Sweden)

    Sandra Isay Saad

    Full Text Available The choice of areas for nature conservation involves the attempt to maximize the benefits, whether by carrying out an economic activity or by the provision of Ecosystem Services. Studies are needed to improve the understanding of the effect of the extent and position along the watershed of restored areas on soil and water conservation. This study aimed to understand how different restoration strategies might reflect in soil conservation and sediment retention. Using InVEST tool, sediment transport was simulated in a small 12 km2 watershed (Posses River, in Southeast Brazil, where one of first Brazilian Payment for Ecosystem Services (PES projects is being carried out, comparing different hypothetical restoration strategies. With 25% of restoration, sediment export decreased by 78% for riparian restoration, and 27% for the steepest slopes restoration. On the other hand, the decrease in soil loss was lower for riparian restoration, with a 16% decrease, while the steepest slopes restoration reduced it by 21%. This mismatch between the reduction of sediment export and soil loss was explained by the fact that forest not only reduces soil loss locally but also traps sediment arriving from the upper parts of the watershed. While the first mechanism is important to provide soil stability, decreasing the risk of landslip, and to maintain agricultural productivity, the second can improve water quality and decrease the risk of silting, with positive effects on the water reservoirs at the outlet of the watershed. This suggests that Riparian and the Steepest Slopes restoration strategies are complementary in the sense of preventing sediments from reaching the water bodies as well as protecting them at their origin (with the reduction of erosion, so it will be advisable to consider the two types of restoration.

  13. Linking the benefits of ecosystem services to sustainable spatial planning of ecological conservation strategies.

    Science.gov (United States)

    Huang, Lin; Cao, Wei; Xu, Xinliang; Fan, Jiangwen; Wang, Junbang

    2018-09-15

    The maintenance and improvement of ecosystem services on the Tibet Plateau are critical for national ecological security in China and are core objectives of ecological conservation in this region. In this paper, ecosystem service benefits of the Tibet Ecological Conservation Project were comprehensively assessed by estimating and mapping the spatiotemporal variation patterns of critical ecosystem services on the Tibet Plateau from 2000 to 2015. Furthermore, we linked the benefit assessment to the sustainable spatial planning of future ecological conservation strategies. Comparing the 8 years before and after the project, the water retention and carbon sink services of the forest, grassland and wetland ecosystems were slightly increased after the project, and the ecosystem sand fixation service has been steadily enhanced. The increasing forage supply service of grassland significantly reduced the grassland carrying pressure and eased the conflict between grassland and livestock. However, enhanced rainfall erosivity occurred due to increased rainfall, and root-layer soils could not recover in a short period of time, both factors have led to a decline in soil conservation service. The warm and humid climate is beneficial for the restoration of ecosystems on the Tibet Plateau, and the implementation of the Tibet Ecological Conservation Project has had a positive effect on the local improvement of ecosystem services. A new spatial planning strategy for ecological conservation was introduced and aims to establish a comprehensive, nationwide system to protect important natural ecosystems and wildlife, and to promote the sustainable use of natural resources. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Ecology

    Science.gov (United States)

    Ternjej, Ivancica; Mihaljevic, Zlatko

    2017-10-01

    Ecology is a science that studies the mutual interactions between organisms and their environment. The fundamental subject of interest in ecology is the individual. Topics of interest to ecologists include the diversity, distribution and number of particular organisms, as well as cooperation and competition between organisms, both within and among ecosystems. Today, ecology is a multidisciplinary science. This is particularly true when the subject of interest is the ecosystem or biosphere, which requires the knowledge and input of biologists, chemists, physicists, geologists, geographists, climatologists, hydrologists and many other experts. Ecology is applied in a science of restoration, repairing disturbed sites through human intervention, in natural resource management, and in environmental impact assessments.

  15. Chemical and Enzymatic Strategies for Bacterial and Mammalian Cell Surface Engineering.

    Science.gov (United States)

    Bi, Xiaobao; Yin, Juan; Chen Guanbang, Ashley; Liu, Chuan-Fa

    2018-06-07

    The cell surface serves important functions such as the regulation of cell-cell and cell-environment interactions. The understanding and manipulation of the cell surface is important for a wide range of fundamental studies of cellular behavior and for biotechnological and medical applications. With the rapid advance of biology, chemistry and materials science, many strategies have been developed for the functionalization of bacterial and mammalian cell surfaces. Here, we review the recent development of chemical and enzymatic approaches to cell surface engineering with particular emphasis on discussing the advantages and limitations of each of these strategies. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The National Strategy of Ecological Transition towards Sustainable Development - International comparisons

    International Nuclear Information System (INIS)

    Kleiber, Florence; Vey, Frederic; Moreau, Sylvain; Bottin, Anne; Baudu-Baret, Claude

    2017-05-01

    The National Strategy of Ecological Transition towards Sustainable Development (SNTEDD) 2015-2020 follows on from the 2010-2013 National Strategy for Sustainable Development. Adopted at the Council of Ministers meeting of 4 February 2015, the SNTEDD identifies four major ecological challenges and nine strategic areas of action. The SNTEDD is monitored by 72 indicators developed via a collaborative process of selection implemented by a special commission of the National Council for Ecological Transition (CNTE) responsible for the indicators. This 'indicators' commission has sought to obtain a perspective on outcomes by means of international comparisons. This study presents initial elements of an analysis of France's situation compared with that of other countries (mostly EU or OECD members) with regard to each of the challenges and areas of action identified in the SNTEDD

  17. Potential strategies for the eradication of multidrug-resistant Gram-negative bacterial infections.

    Science.gov (United States)

    Huwaitat, Rawan; McCloskey, Alice P; Gilmore, Brendan F; Laverty, Garry

    2016-07-01

    Antimicrobial resistance is one of the leading threats to society. The increasing burden of multidrug-resistant Gram-negative infection is particularly concerning as such bacteria are demonstrating resistance to nearly all currently licensed therapies. Various strategies have been hypothesized to treat multidrug-resistant Gram-negative infections including: targeting the Gram-negative outer membrane; neutralization of lipopolysaccharide; inhibition of bacterial efflux pumps and prevention of protein folding. Silver and silver nanoparticles, fusogenic liposomes and nanotubes are potential strategies for extending the activity of licensed, Gram-positive selective, antibiotics to Gram-negatives. This may serve as a strategy to fill the current void in pharmaceutical development in the short term. This review outlines the most promising strategies that could be implemented to solve the threat of multidrug-resistant Gram-negative infections.

  18. Microbial ecology-based methods to characterize the bacterial communities of non-model insects.

    Science.gov (United States)

    Prosdocimi, Erica M; Mapelli, Francesca; Gonella, Elena; Borin, Sara; Crotti, Elena

    2015-12-01

    Among the animals of the Kingdom Animalia, insects are unparalleled for their widespread diffusion, diversity and number of occupied ecological niches. In recent years they have raised researcher interest not only because of their importance as human and agricultural pests, disease vectors and as useful breeding species (e.g. honeybee and silkworm), but also because of their suitability as animal models. It is now fully recognized that microorganisms form symbiotic relationships with insects, influencing their survival, fitness, development, mating habits and the immune system and other aspects of the biology and ecology of the insect host. Thus, any research aimed at deepening the knowledge of any given insect species (perhaps species of applied interest or species emerging as novel pests or vectors) must consider the characterization of the associated microbiome. The present review critically examines the microbiology and molecular ecology techniques that can be applied to the taxonomical and functional analysis of the microbiome of non-model insects. Our goal is to provide an overview of current approaches and methods addressing the ecology and functions of microorganisms and microbiomes associated with insects. Our focus is on operational details, aiming to provide a concise guide to currently available advanced techniques, in an effort to extend insect microbiome research beyond simple descriptions of microbial communities. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Microbial interactions involving sulfur bacteria : implications for the ecology and evolution of bacterial communities

    NARCIS (Netherlands)

    Overmann, J; van Gemerden, H

    2000-01-01

    A major goal of microbial ecology is the identification and characterization of those microorganisms which govern transformations in natural ecosystems. This review summarizes our present knowledge of microbial interactions in the natural sulfur cycle. Central to the discussion is the recent

  20. ECOLOGICAL AND ECONOMIC DYNAMICS OF THE SHUNDE AGRICULTURAL SYSTEM UNDER CHINA'S SMALL CITY DEVELOPMENT STRATEGY

    Science.gov (United States)

    The development of small cities has been adopted as the main strategy to make full use of extra labor in the rural areas of China. The ecological and economic consequences of this development will affect over 100 million people and change the organization of agricultural systems ...

  1. Economical and ecological comparison of granular activated carbon (GAC) adsorber refill strategies.

    Science.gov (United States)

    Bayer, Peter; Heuer, Edda; Karl, Ute; Finkel, Michael

    2005-05-01

    Technical constraints can leave a considerable freedom in the design of a technology, production or service strategy. Choosing between economical or ecological decision criteria then characteristically leads to controversial solutions of ideal systems. For the adaptation of granular-activated carbon (GAC) fixed beds, various technical factors determine the adsorber volume required to achieve a desired service life. In considering carbon replacement and recycling, a variety of refill strategies are available that differ in terms of refill interval, respective adsorber volume, and time-dependent use of virgin, as well as recycled GAC. Focusing on the treatment of contaminant groundwater, we compare cost-optimal reactor configurations and refill strategies to the ecologically best alternatives. Costs and consumption of GAC are quantified within a technical-economical framework. The emissions from GAC production out of hard coal, transport and recycling are equally derived through a life cycle impact assessment. It is shown how high discount rates lead to a preference of small fixed-bed volumes, and accordingly, a high number of refills. For fixed discount rates, the investigation reveals that both the economical as well as ecological assessment of refill strategies are especially sensitive to the relative valuation of virgin and recycled GAC. Since recycling results in economic and ecological benefits, optimized systems thus may differ only slightly.

  2. Life cycle assessment-driven selection of industrial ecology strategies.

    Science.gov (United States)

    Ardente, Fulvio; Cellura, Maurizio; Lo Brano, Valerio; Mistretta, Marina

    2010-01-01

    The paper presents an application of the Life-Cycle Assessment (LCA) to the planning and environmental management of an “eco-industrial cluster.” A feasibility study of industrial symbiosis in southern Italy is carried out, where interlinked companies share subproducts and scraps, services, structures, and plants to reduce the related environmental impact. In particular, the research focuses on new recycling solutions to create open recycling loops in which plastic subproducts and scraps are transferred to external production systems. The main environmental benefits are the reduction of resource depletion, air emissions, and landfilled wastes. The proposed strategies are also economically viable and they suggest cost abatement for the involved companies. This research shows the need for a multidisciplinary approach to data processing and to complexity managing of the investigated systems. In this context, life-cycle thinking is required to be promoted throughout the economy, as well to be as a part of all decisions on products and other criteria such as functionality, health, and safety. The Life-Cycle Assessment approach can be assumed as a methodology for influencing decision makers to make sustainable choices.

  3. Distribution and life strategies of two bacterial populations in a eutrophic lake

    Science.gov (United States)

    Weinbauer; Hofle

    1998-10-01

    Monoclonal antibodies and epifluorescence microscopy were used to determine the depth distribution of two indigenous bacterial populations in the stratified Lake Plusssee and characterize their life strategies. Populations of Comamonas acidovorans PX54 showed a depth distribution with maximum abundances in the oxic epilimnion, whereas Aeromonas hydrophila PU7718 showed a depth distribution with maximum abundances in the anoxic thermocline layer (metalimnion), i. e., in the water layer with the highest microbial activity. Resistance of PX54 to protist grazing and high metabolic versatility and growth rate of PU7718 were the most important life strategy traits for explaining the depth distribution of the two bacterial populations. Maximum abundance of PX54 was 16,000 cells per ml, and maximum abundance of PU7718 was 20,000 cells per ml. Determination of bacterial productivity in dilution cultures with different-size fractions of dissolved organic matter (DOM) from lake water indicates that low-molecular-weight (LMW) DOM is less bioreactive than total DOM (TDOM). The abundance and growth rate of PU7718 were highest in the TDOM fractions, whereas those of PX54 were highest in the LMW DOM fraction, demonstrating that PX54 can grow well on the less bioreactive DOM fraction. We estimated that 13 to 24% of the entire bacterial community and 14% of PU7718 were removed by viral lysis, whereas no significant effect of viral lysis on PX54 could be detected. Growth rates of PX54 (0.11 to 0.13 h-1) were higher than those of the entire bacterial community (0.04 to 0.08 h-1) but lower than those of PU7718 (0.26 to 0.31 h-1). In undiluted cultures, the growth rates were significantly lower, pointing to density effects such as resource limitation or antibiosis, and the effects were stronger for PU7718 and the entire bacterial community than for PX54. Life strategy characterizations based on data from literature and this study revealed that the fast-growing and metabolically

  4. Exploiting rRNA operon copy number to investigate bacterial reproductive strategies.

    Science.gov (United States)

    Roller, Benjamin R K; Stoddard, Steven F; Schmidt, Thomas M

    2016-09-12

    The potential for rapid reproduction is a hallmark of microbial life, but microbes in nature must also survive and compete when growth is constrained by resource availability. Successful reproduction requires different strategies when resources are scarce and when they are abundant 1,2 , but a systematic framework for predicting these reproductive strategies in bacteria has not been available. Here, we show that the number of ribosomal RNA operons (rrn) in bacterial genomes predicts two important components of reproduction-growth rate and growth efficiency-which are favoured under contrasting regimes of resource availability 3,4 . We find that the maximum reproductive rate of bacteria doubles with a doubling of rrn copy number, and the efficiency of carbon use is inversely related to maximal growth rate and rrn copy number. We also identify a feasible explanation for these patterns: the rate and yield of protein synthesis mirror the overall pattern in maximum growth rate and growth efficiency. Furthermore, comparative analysis of genomes from 1,167 bacterial species reveals that rrn copy number predicts traits associated with resource availability, including chemotaxis and genome streamlining. Genome-wide patterns of orthologous gene content covary with rrn copy number, suggesting convergent evolution in response to resource availability. Our findings imply that basic cellular processes adapt in contrasting ways to long-term differences in resource availability. They also establish a basis for predicting changes in bacterial community composition in response to resource perturbations using rrn copy number measurements 5 or inferences 6,7 .

  5. A soil-specific agro-ecological strategy for sustainable production in Argentina farm fields

    Science.gov (United States)

    Zamora, Martin; Barbera, Agustin; Castro-Franco, Mauricio; Hansson, Alejandro; Domenech, Marisa

    2017-04-01

    The continuous increment of frequencies and doses of pesticides, glyphosate and fertilizers, the deterioration of the structure, biotic balance and fertility of soils and the ground water pollution are characteristics of the current Argentinian agricultural model. In this context, agro-ecological innovations are needed to develop a real sustainable agriculture, enhancing the food supply. Precision agriculture technologies can strengthen the expansion of agro-ecological farming in experimental farm fields. The aim of this study was to propose a soil-specific agro-ecological strategy for sustainable production at field scale focused on the use of soil sensors and digital soil mapping techniques. This strategy has been developed in 15 hectares transition agro-ecological farm field, located at Barrow Experimental Station (Lat:-38.322844, Lon:-60.25572) Argentina. The strategy included five steps: (i) to measure apparent electrical conductivity (ECa) and elevation within agro-ecological farm field; (ii) to apply a clustering method using MULTISPATI-PCA algorithm to delimitate three soil-specific zones (Z1, Z2 and Z3); (iii) to determine three soil sampling points by zone, using conditioned Latin hypercube method, in addition to elevation and ECa as auxiliary information; (iv) to collect soil samples at 2-10 cm depth in each point and to determine in laboratory: total organic carbon content (TOC), cation-exchange capacity (CEC), pH and phosphorus availability (P-Bray). In addition, soil bulk density (SBD) was measured at 0-20 cm depth. Finally, (v) according to each soil-specific zone, a management strategy was recommended. Important differences in soil properties among zones could suggest that the strategy developed was able to apply an agro ecological soil-specific practice management. pH and P-Bray were significantly (pfertilizer and also rotating plots with high stocking rate. The aim is to increase soil organic matter content and CEC. Furthermore, P content will be

  6. Illustrations with Real Examples of Using Ecological Regulation Strategies Against Crop Pests in China

    Institute of Scientific and Technical Information of China (English)

    Guo Yuyuan; Liang Gemei

    2006-01-01

    In this paper, a series of examples from China, including those using ecological regulation strategies successfully to keep crop pests under control and those making more damages of crop pests caused by wrong cropping systems, crop distributions or extensive cultivation, were given and analyzed. From these, two pieces of experience were enlightened as follows: the first, the reforms of cropping systems and crop distributions must be beneficial to pest control or at least not increase the damage of crop pests; the second, we should further clarify the relationship between population dynamics of pests and cropping system/crop distribution, the basis for correctly laying down the ecological regulation systems.

  7. Directed antigen delivery as a vaccine strategy for an intracellular bacterial pathogen

    Science.gov (United States)

    Bouwer, H. G. Archie; Alberti-Segui, Christine; Montfort, Megan J.; Berkowitz, Nathan D.; Higgins, Darren E.

    2006-03-01

    We have developed a vaccine strategy for generating an attenuated strain of an intracellular bacterial pathogen that, after uptake by professional antigen-presenting cells, does not replicate intracellularly and is readily killed. However, after degradation of the vaccine strain within the phagolysosome, target antigens are released into the cytosol for endogenous processing and presentation for stimulation of CD8+ effector T cells. Applying this strategy to the model intracellular pathogen Listeria monocytogenes, we show that an intracellular replication-deficient vaccine strain is cleared rapidly in normal and immunocompromised animals, yet antigen-specific CD8+ effector T cells are stimulated after immunization. Furthermore, animals immunized with the intracellular replication-deficient vaccine strain are resistant to lethal challenge with a virulent WT strain of L. monocytogenes. These studies suggest a general strategy for developing safe and effective, attenuated intracellular replication-deficient vaccine strains for stimulation of protective immune responses against intracellular bacterial pathogens. CD8+ T cell | replication-deficient | Listeria monocytogenes

  8. Disturbance Regimes Predictably Alter Diversity in an Ecologically Complex Bacterial System

    Directory of Open Access Journals (Sweden)

    Sean M. Gibbons

    2016-12-01

    Full Text Available Diversity is often associated with the functional stability of ecological communities from microbes to macroorganisms. Understanding how diversity responds to environmental perturbations and the consequences of this relationship for ecosystem function are thus central challenges in microbial ecology. Unimodal diversity-disturbance relationships, in which maximum diversity occurs at intermediate levels of disturbance, have been predicted for ecosystems where life history tradeoffs separate organisms along a disturbance gradient. However, empirical support for such peaked relationships in macrosystems is mixed, and few studies have explored these relationships in microbial systems. Here we use complex microbial microcosm communities to systematically determine diversity-disturbance relationships over a range of disturbance regimes. We observed a reproducible switch between community states, which gave rise to transient diversity maxima when community states were forced to mix. Communities showed reduced compositional stability when diversity was highest. To further explore these dynamics, we formulated a simple model that reveals specific regimes under which diversity maxima are stable. Together, our results show how both unimodal and non-unimodal diversity-disturbance relationships can be observed as a system switches between two distinct microbial community states; this process likely occurs across a wide range of spatially and temporally heterogeneous microbial ecosystems.

  9. Bioactive Compound Synthetic Capacity and Ecological Significance of Marine Bacterial Genus Pseudoalteromonas

    Directory of Open Access Journals (Sweden)

    John P. Bowman

    2007-12-01

    Full Text Available The genus Pseudoalteromonas is a marine group of bacteria belonging to theclass Gammaproteobacteria that has come to attention in the natural product andmicrobial ecology science fields in the last decade. Pigmented species of the genus havebeen shown to produce an array of low and high molecular weight compounds withantimicrobial, anti-fouling, algicidal and various pharmaceutically-relevant activities.Compounds formed include toxic proteins, polyanionic exopolymers, substitutedphenolic and pyrolle-containing alkaloids, cyclic peptides and a range of bromine-substituted compounds. Ecologically, Pseudoalteromonas appears significant and to datehas been shown to influence biofilm formation in various marine econiches; involved inpredator-like interactions within the microbial loop; influence settlement, germinationand metamorphosis of various invertebrate and algal species; and may also be adopted bymarine flora and fauna as defensive agents. Studies have been so far limited to arelatively small subset of strains compared to the known diversity of the genussuggesting that many more discoveries of novel natural products as well as ecologicalconnections these may have in the marine ecosystem remain to be made.

  10. Ecology

    International Nuclear Information System (INIS)

    Kalusche, D.

    1978-01-01

    The book turns to the freshment, the teacher, for preparation of ecological topics for lessons, but also to pupils of the secondary stage II, and the main course ecology. The book was knowingly held simple with the restriction to: the ecosystem and its abiotic basic functions, simple articles on population biology, bioceonotic balance ith the questions of niche formation and the life form types coherent with it, of the substance and energy household, the production biology and space-wise and time-wise differentations within an ecological system form the main points. A central role in the volume is given to the illustrations. Their variety is to show and deepen the coherences shown. (orig./HP) [de

  11. Evolutionary and ecological forces that shape the bacterial communities of the human gut

    Science.gov (United States)

    Messer, Jeannette S.; Liechty, Emma R; Vogel, Olivia A.; Chang, Eugene B.

    2017-01-01

    Since microbes were first described in the mid-1600's, we have come to appreciate that they live all around and within us with both beneficial and detrimental effects on nearly every aspect of our lives. The human gastrointestinal tract is inhabited by a dynamic community of trillions of bacteria that constantly interact with each other and their human host. The acquisition of these bacteria is not stochastic, but determined by circumstance (environment), host rules (genetics, immune state, mucus, etc), and dynamic self-selection among microbes to form stable, resilient communities that are in balance with the host. In this review, we will discuss how these factors lead to formation of the gut bacterial community and influence its interactions with the host. We will also address how gut bacteria contribute to disease and how they could potentially be targeted to prevent and treat a variety of human ailments. PMID:28145439

  12. The physicochemical process of bacterial attachment to abiotic surfaces: Challenges for mechanistic studies, predictability and the development of control strategies.

    Science.gov (United States)

    Wang, Yi; Lee, Sui Mae; Dykes, Gary

    2015-01-01

    Bacterial attachment to abiotic surfaces can be explained as a physicochemical process. Mechanisms of the process have been widely studied but are not yet well understood due to their complexity. Physicochemical processes can be influenced by various interactions and factors in attachment systems, including, but not limited to, hydrophobic interactions, electrostatic interactions and substratum surface roughness. Mechanistic models and control strategies for bacterial attachment to abiotic surfaces have been established based on the current understanding of the attachment process and the interactions involved. Due to a lack of process control and standardization in the methodologies used to study the mechanisms of bacterial attachment, however, various challenges are apparent in the development of models and control strategies. In this review, the physicochemical mechanisms, interactions and factors affecting the process of bacterial attachment to abiotic surfaces are described. Mechanistic models established based on these parameters are discussed in terms of their limitations. Currently employed methods to study these parameters and bacterial attachment are critically compared. The roles of these parameters in the development of control strategies for bacterial attachment are reviewed, and the challenges that arise in developing mechanistic models and control strategies are assessed.

  13. Culturally compelling strategies for behaviour change: a social ecology model and case study in malaria prevention.

    Science.gov (United States)

    Panter-Brick, Catherine; Clarke, Sian E; Lomas, Heather; Pinder, Margaret; Lindsay, Steve W

    2006-06-01

    Behaviour change is notoriously difficult to initiate and sustain, and the reasons why efforts to promote healthy behaviours fail are coming under increasing scrutiny. To be successful, health interventions should build on existing practices, skills and priorities, recognise the constraints on human behaviour, and either feature community mobilisation or target those most receptive to change. Furthermore, interventions should strive to be culturally compelling, not merely culturally appropriate: they must engage local communities and nestle within social and ecological landscapes. In this paper, we propose a social ecology perspective to make explicit the links between intention to change, actual behaviour change, and subsequent health impact, as relating to both theory-based models and practical strategies for triggering behaviour change. A social ecology model focuses attention on the contexts of behaviour when designing, implementing or critically evaluating interventions. As a case study, we reflect on a community-directed intervention in rural Gambia designed to reduce malaria by promoting a relatively simple and low-cost behaviour: repairing holes in mosquito bednets. In phase 1, contextual information on bednet usage, transactions and repairs (the 'social lives' of nets) was documented. In phase 2 (intervention), songs were composed and posters displayed by community members to encourage repairs, creating a sense of ownership and a compelling medium for the transmission of health messages. In phase 3 (evaluation), qualitative and quantitative data showed that household responses were particularly rapid and extensive, with significant increase in bednet repairs (psocial ecology-of behaviour practices that are the bedrock of health interventions.

  14. The bacterial community structure of hydrocarbon-polluted marine environments as the basis for the definition of an ecological index of hydrocarbon exposure.

    Science.gov (United States)

    Lozada, Mariana; Marcos, Magalí S; Commendatore, Marta G; Gil, Mónica N; Dionisi, Hebe M

    2014-09-17

    The aim of this study was to design a molecular biological tool, using information provided by amplicon pyrosequencing of 16S rRNA genes, that could be suitable for environmental assessment and bioremediation in marine ecosystems. We selected 63 bacterial genera that were previously linked to hydrocarbon biodegradation, representing a minimum sample of the bacterial guild associated with this process. We defined an ecological indicator (ecological index of hydrocarbon exposure, EIHE) using the relative abundance values of these genera obtained by pyrotag analysis. This index reflects the proportion of the bacterial community that is potentially capable of biodegrading hydrocarbons. When the bacterial community structures of intertidal sediments from two sites with different pollution histories were analyzed, 16 of the selected genera (25%) were significantly overrepresented with respect to the pristine site, in at least one of the samples from the polluted site. Although the relative abundances of individual genera associated with hydrocarbon biodegradation were generally low in samples from the polluted site, EIHE values were 4 times higher than those in the pristine sample, with at least 5% of the bacterial community in the sediments being represented by the selected genera. EIHE values were also calculated in other oil-exposed marine sediments as well as in seawater using public datasets from experimental systems and field studies. In all cases, the EIHE was significantly higher in oiled than in unpolluted samples, suggesting that this tool could be used as an estimator of the hydrocarbon-degrading potential of microbial communities.

  15. Classical Ecological Restoration and its Current Challenges: Assisted Migration as an Adaptation Strategy to Climate Change

    Directory of Open Access Journals (Sweden)

    Pilar A. Gómez-Ruiz

    2017-06-01

    Full Text Available Ecological restoration is a very active area in ecology and of great importance for ecosystems management. Despite of being a relatively young discipline, the classical concepts of restoration seem, at present, impractical considering the great challenges generated by modification and destruction of ecosystems. This is due to anthropic activities (deforestation, change of land use, pollution and global climate change. In the classic definition of restoration, the objective is to recover the degraded ecosystem to the same conditions of a historical reference state. However, nowadays the ecosystems return to a state prior to the disturbances seems unviable, because the thresholds of resilience have already been overcome. Additionally, climate change is causing environmental changes at an unprecedented rate. For this reason, ecological restoration needs to unite efforts of diverse actors to recover ecosystems that can be sustainable and functional in the future, where the species could be able to tolerate the environmental conditions that will exist in the long term. Assisted migration has been proposed as a conservation strategy; it is defined as the translocation of species to new locations outside their known range of distribution. In the current context of loss of diversity and ecosystems, this strategy could be fundamental for the formation of new communities that can later become novel ecosystems where species that are fundamental to the dynamics of ecosystems can persist and, at the same time, recover function, structure and resilience.

  16. Strategies for fitting nonlinear ecological models in R, AD Model Builder, and BUGS

    Science.gov (United States)

    Bolker, Benjamin M.; Gardner, Beth; Maunder, Mark; Berg, Casper W.; Brooks, Mollie; Comita, Liza; Crone, Elizabeth; Cubaynes, Sarah; Davies, Trevor; de Valpine, Perry; Ford, Jessica; Gimenez, Olivier; Kéry, Marc; Kim, Eun Jung; Lennert-Cody, Cleridy; Magunsson, Arni; Martell, Steve; Nash, John; Nielson, Anders; Regentz, Jim; Skaug, Hans; Zipkin, Elise

    2013-01-01

    1. Ecologists often use nonlinear fitting techniques to estimate the parameters of complex ecological models, with attendant frustration. This paper compares three open-source model fitting tools and discusses general strategies for defining and fitting models. 2. R is convenient and (relatively) easy to learn, AD Model Builder is fast and robust but comes with a steep learning curve, while BUGS provides the greatest flexibility at the price of speed. 3. Our model-fitting suggestions range from general cultural advice (where possible, use the tools and models that are most common in your subfield) to specific suggestions about how to change the mathematical description of models to make them more amenable to parameter estimation. 4. A companion web site (https://groups.nceas.ucsb.edu/nonlinear-modeling/projects) presents detailed examples of application of the three tools to a variety of typical ecological estimation problems; each example links both to a detailed project report and to full source code and data.

  17. Biofilm-mediated Antibiotic-resistant Oral Bacterial Infections: Mechanism and Combat Strategies.

    Science.gov (United States)

    Kanwar, Indulata; Sah, Abhishek K; Suresh, Preeti K

    2017-01-01

    Oral diseases like dental caries and periodontal disease are directly associated with the capability of bacteria to form biofilm. Periodontal diseases have been associated to anaerobic Gram-negative bacteria forming a subgingival plaque (Porphyromonas gingivalis, Actinobacillus, Prevotella and Fusobacterium). Biofilm is a complex bacterial community that is highly resistant to antibiotics and human immunity. Biofilm communities are the causative agents of biological developments such as dental caries, periodontitis, peri-implantitis and causing periodontal tissue breakdown. The review recapitulates the latest advancements in treatment of clinical biofilm infections and scientific investigations, while these novel anti-biofilm strategies are still in nascent phases of development, efforts dedicated to these technologies could ultimately lead to anti-biofilm therapies that are superior to the current antibiotic treatment. This paper provides a review of the literature focusing on the studies on biofilm in the oral cavity, formation of dental plaque biofilm, drug resistance of bacterial biofilm and the antibiofilm approaches as biofilm preventive agents in dentistry, and their mechanism of biofilm inhibition. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Economic and ecological optimal strategies of management of the system of regional solid waste disposal

    Directory of Open Access Journals (Sweden)

    Samoylik Marina S.

    2014-01-01

    Full Text Available The article develops an economic and ecological model of optimal management of the system of solid waste disposal at the regional level, identifies its target functions and forms optimisation scenarios of management of this sphere with theoretically optimal parameters’ values. Based on the model of management of the sphere of solid waste disposal the article forms an algorithm of identification of optimal managerial strategies and mechanisms of their realisation, which allows solution of the set tasks of optimisation of development of the sphere of solid waste disposal at a given set of values and parameters of the state of the system for a specific type of life cycle of solid waste and different subjects of this sphere. The developed model has a number of feasible solutions and, consequently, offers selection of the best of them with consideration of target functions. The article conducts a SWOT analysis of the current state of solid waste disposal in the Poltava region and identifies a necessity of development of a relevant strategy on the basis of the developed economic and ecological model with consideration of optimisation of mutually opposite criteria: ecological risk for the population from the sphere of solid waste disposal and total expenditures for this sphere functioning. The article conducts modelling of this situation by basic (current situation and alternative scenarios and finds out that, at this stage, it is most expedient to build in the region four sorting lines and five regional solid waste grounds, while expenditures on this sphere are UAH 62.0 million per year, income from secondary raw material sales – UAH 71.2 per year and reduction of the ecological risk – UAH 13 million per year.

  19. Adaptations of a Yucatec Maya Multiple-Use Ecological Management Strategy to Ecotourism

    Directory of Open Access Journals (Sweden)

    Eduardo García-Frapolli

    2008-12-01

    Full Text Available Over the last 40 years, the Yucatan Peninsula has experienced the implementation and promotion of development programs that have economically and ecologically shaped this region of Mexico. Nowadays, tourist development has become the principal catalyst of social, economic, and ecological changes in the region. All these programs, which are based on a specialization rationale, have historically clashed with traditional Yucatec Maya management of natural resources. Using participant observation, informal and semi-structured interviews, and life-history interviews, we carried out an assessment of a Yucatec Maya natural resources management system implemented by three indigenous communities located within a natural protected area. The assessment, intended as an examination of the land-use practices and productive strategies currently implemented by households, was framed within an ecological-economic approach to ecosystems appropriation. To examine the influence of tourism on the multiple-use strategy, we contrasted productive activities among households engaged primarily in ecotourism with those more oriented toward traditional agriculture. Results show that households from these communities allocated an annual average of 586 work days to implement a total of 15 activities in five different land-use units, and that those figures vary significantly in accordance with households' productive strategy (agriculture oriented or service oriented. As the region is quickly becoming an important tourist destination and ecotourism is replacing many traditional activities, we discuss the need for a balance between traditional and alternative economic activities that will allow Yucatec Maya communities to diversify their economic options without compromising existing local management practices.

  20. Strategies for fitting nonlinear ecological models in R, AD Model Builder, and BUGS

    DEFF Research Database (Denmark)

    Bolker, B.M.; Gardner, B.; Maunder, M.

    2013-01-01

    Ecologists often use nonlinear fitting techniques to estimate the parameters of complex ecological models, with attendant frustration. This paper compares three open-source model fitting tools and discusses general strategies for defining and fitting models. R is convenient and (relatively) easy...... to learn, AD Model Builder is fast and robust but comes with a steep learning curve, while BUGS provides the greatest flexibility at the price of speed. Our model-fitting suggestions range from general cultural advice (where possible, use the tools and models that are most common in your subfield...

  1. Responses of soil microbial biomass and bacterial community structure to closed-off management (an ecological natural restoration measures): A case study of Dongting Lake wetland, middle China.

    Science.gov (United States)

    Dai, Juan; Wu, Haipeng; Zhang, Chang; Zeng, Guangming; Liang, Jie; Guo, Shenglian; Li, Xiaodong; Huang, Lu; Lu, Lunhui; Yuan, Yujie

    2016-09-01

    Soil microbial biomass (SMB) and bacterial community structure, which are critical to global ecosystem and fundamental ecological processes, are sensitive to anthropogenic activities and environmental conditions. In this study, we examined the possible effects of closed-off management (an ecological natural restoration measures, ban on anthropogenic activity, widely employed for many important wetlands) on SMB, soil bacterial community structure and functional marker genes of nitrogen cycling in Dongting Lake wetland. Soil samples were collected from management area (MA) and contrast area (CA: human activities, such as hunting, fishing and draining, are permitted) in November 2013 and April 2014. Soil properties, microbial biomass carbon (MBC), and bacterial community structure were investigated. Comparison of the values of MA and CA showed that SMB and bacterial community diversity of the MA had a significant increase after 7 years closed-off management. The mean value of Shannon-Weiner diversity index of MA and CA respectively were 2.85 and 2.07. The gene copy numbers of 16S rRNA and nosZ of MA were significant higher than those of CA. the gene copy numbers of ammonia-oxidizing archaea (AOA) and nirK of MA were significant lower than those of CA. However, there was no significant change in the gene copy numbers of ammonia-oxidizing bacteria (AOB) and nirS. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Bacterial Exopolysaccharide mediated heavy metal removal: A Review on biosynthesis, mechanism and remediation strategies.

    Science.gov (United States)

    Gupta, Pratima; Diwan, Batul

    2017-03-01

    Heavy metal contamination has been recognized as a major public health risk, particularly in developing countries and their toxicological manifestations are well known. Conventional remediation strategies are either expensive or they generate toxic by-products, which adversely affect the environment. Therefore, necessity for an environmentally safe strategy motivates interest towards biological techniques. One of such most profoundly driven approach in recent times is biosorption through microbial biomass and their products. Extracellular polymeric substances are such complex blend of high molecular weight microbial (prokaryotic and eukaryotic) biopolymers. They are mainly composed of proteins, polysaccharides, uronic acids, humic substances, lipids etc. One of its essential constituent is the exopolysaccharide (EPS) released out of self defense against harsh conditions of starvation, pH and temperature, hence it displays exemplary physiological, rheological and physio-chemical properties. Its net anionic makeup allows the biopolymer to effectively sequester positively charged heavy metal ions. The polysaccharide has been expounded deeply in this article with reference to its biosynthesis and emphasizes heavy metal sorption abilities of polymer in terms of mechanism of action and remediation. It reports current investigation and strategic advancements in dealing bacterial cells and their EPS in diverse forms - mixed culture EPS, single cell EPS, live, dead or immobilized EPS. A significant scrutiny is also involved highlighting the existing challenges that still lie in the path of commercialization. The article enlightens the potential of EPS to bring about bio-detoxification of heavy metal contaminated terrestrial and aquatic systems in highly sustainable, economic and eco-friendly manner.

  3. Strategies for cost-effective and enhanced production of bacterial cellulose.

    Science.gov (United States)

    Islam, Mazhar Ul; Ullah, Muhammad Wajid; Khan, Shaukat; Shah, Nasrullah; Park, Joong Kon

    2017-09-01

    Bacterial cellulose (BC) has received substantial attention because of its high purity, mechanical strength, crystallinity, liquid-absorbing capabilities, biocompatibility, and biodegradability etc. These properties allow BC to be used in various fields, especially in industries producing medical, electronic, and food products etc. A major discrepancy associated with BC is its high production cost, usually much higher than the plant cellulose. To address this limitations, researchers have developed several strategies for enhanced production of BC including the designing of advanced reactors and utilization of various carbon sources. Another promising approach is the production of BC from waste materials such as food, industrial, agricultural, and brewery wastes etc. which not only reduces the overall BC production cost but is also environment-friendly. Besides, exploration of novel and efficient BC producing microbial strains provides impressive boost to the BC production processes. To this end, development of genetically engineered microbial strains has proven useful for enhanced BC production. In this review, we have summarized major efforts to enhance BC production in order to make it a cost-effective biopolymer. This review can be of interest to researchers investigating strategies for enhanced BC production, as well as companies exploring pilot projects to scale up BC production for industrial applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Systematically Altering Bacterial SOS Activity under Stress Reveals Therapeutic Strategies for Potentiating Antibiotics.

    Science.gov (United States)

    Mo, Charlie Y; Manning, Sara A; Roggiani, Manuela; Culyba, Matthew J; Samuels, Amanda N; Sniegowski, Paul D; Goulian, Mark; Kohli, Rahul M

    2016-01-01

    The bacterial SOS response is a DNA damage repair network that is strongly implicated in both survival and acquired drug resistance under antimicrobial stress. The two SOS regulators, LexA and RecA, have therefore emerged as potential targets for adjuvant therapies aimed at combating resistance, although many open questions remain. For example, it is not well understood whether SOS hyperactivation is a viable therapeutic approach or whether LexA or RecA is a better target. Furthermore, it is important to determine which antimicrobials could serve as the best treatment partners with SOS-targeting adjuvants. Here we derived Escherichia coli strains that have mutations in either lexA or recA genes in order to cover the full spectrum of possible SOS activity levels. We then systematically analyzed a wide range of antimicrobials by comparing the mean inhibitory concentrations (MICs) and induced mutation rates for each drug-strain combination. We first show that significant changes in MICs are largely confined to DNA-damaging antibiotics, with strains containing a constitutively repressed SOS response impacted to a greater extent than hyperactivated strains. Second, antibiotic-induced mutation rates were suppressed when SOS activity was reduced, and this trend was observed across a wider spectrum of antibiotics. Finally, perturbing either LexA or RecA proved to be equally viable strategies for targeting the SOS response. Our work provides support for multiple adjuvant strategies, while also suggesting that the combination of an SOS inhibitor with a DNA-damaging antibiotic could offer the best potential for lowering MICs and decreasing acquired drug resistance. IMPORTANCE Our antibiotic arsenal is becoming depleted, in part, because bacteria have the ability to rapidly adapt and acquire resistance to our best agents. The SOS pathway, a widely conserved DNA damage stress response in bacteria, is activated by many antibiotics and has been shown to play central role in

  5. Evaluation of bacterial strategies to promote the bioavailability of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, A.R.; Karlson, U. [Dept. of Environmental Chemistry and Microbiology, National Environmental Research Inst., Roskilde (Denmark)

    2004-07-01

    Polycyclic aromatic hydrocarbon (PAHs)-degrading bacteria may enhance the bioavailability of PAHs by excreting biosurfactants, by production of extracellular polymeric substances, or by forming biofilms. We tested these hypotheses in pure cultures of PAHs-degrading bacterial strains. Most of the strains did not substantially reduce the surface tension when grown on PAHs in liquid shaken cultures. Thus, pseudo-solubilization of PAHs in biosurfactant micelles seems not to be a general strategy for these isolates to enhance PAHs-bioavailability. Three semi-colloid Sphingomonas polysaccharides all increased the solubility of PAHs (Gellan 1.3- to 5.4-fold, Welan 1.8- to 6.0-fold and Rhamsan 2.4- to 9.0-fold). The increases were most pronounced for the more hydrophobic PAHs. The polysaccharide-sorbed PAHs were bioavailable. Mineralization rates of 9-[{sup 14}C]-phenanthrene and 3-[{sup 14}C]-fluoranthene by Sphingobium EPA505, were similar with and without sphingans, indicating that mass-transfer rates from PAHs crystals to the bulk liquid were unaffected by the polysaccharides. Biofilm formation on PAHs crystals may favor the diffusive mass transfer of PAHs from crystals to the bacterial cells. A majority of the PAHs-degraders tested formed biofilms in microtiter wells coated with PAHs crystals. For strains capable of growing on different PAHs; the more soluble the PAHs, the lower the percentage of cells attached. Biofilm formation on PAHs-sources was the predominant mechanism among the tested bacteria to overcome mass transfer limitations when growing on poorly soluble PAHs. (orig.)

  6. A regional strategy for ecological sustainability: A case study in Southwest China.

    Science.gov (United States)

    Wu, Xue; Liu, Shiliang; Cheng, Fangyan; Hou, Xiaoyun; Zhang, Yueqiu; Dong, Shikui; Liu, Guohua

    2018-03-01

    Partitioning, a method considering environmental protection and development potential, is an effective way to provide regional management strategies to maintain ecological sustainability. In this study, we provide a large-scale regional division approach and present a strategy for Southwest China, which also has extremely high development potential because of the "Western development" policy. Based on the superposition of 15 factors, including species diversity, pattern restriction, agricultural potential, accessibility, urbanization potential, and topographical limitations, the environmental value and development benefit in the region were quantified spatially by weighting the sum of indicators within environmental and development categories. By comparing the scores with their respective median values, the study area was divided into four different strategy zones: Conserve zones (34.94%), Construction zones (32.95%), Conflict zones (16.96%), and Low-tension zones (15.16%). The Conflict zones in which environmental value and development benefit were both higher than the respective medians were separated further into the following 5 levels: Extreme conflict (36.20%), Serious conflict (28.07%), Moderate conflict (12.28%), Minor conflict (6.55%), and Slight conflict (16.91%). We found that 9.04% of nature reserves were in Conflict zones, and thus should be given more attention. This study provides a simple and feasible method for regional partitioning, as well as comprehensive support that weighs both the environmental value and development benefit for China's current Ecological Red Line and space planning and for regional management in similar situations. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. The national strategy for an ecologic transition towards a sustainable development (SNTEDD) - Preliminary draft 2014-2020

    International Nuclear Information System (INIS)

    2014-01-01

    After having outlined that the ecologic transition is a requirement for economy and society, this document presents the nine main lines of the French national strategy for an ecologic transition towards a sustainable development. These main lines as well as the associated priorities (two to five priorities are associated with each main line) are discussed. Objectives and related public initiatives (plan, drafts, bill projects) are also mentioned. The nine main lines are: to develop sustainable and resilient territories, to commit to a circular and low-carbon economy, to prevent and to reduce environmental, social and land inequities, to invent new economic and financial models, to support the ecologic evolution of economic activities, to direct knowledge production, research and innovation towards ecologic transition, to teach, train and heighten awareness for ecologic transition, to mobilize actors at all levels, and to promote sustainable development at the European and world levels

  8. Bacterial Exopolysaccharide mediated heavy metal removal: A Review on biosynthesis, mechanism and remediation strategies

    Directory of Open Access Journals (Sweden)

    Pratima Gupta

    2017-03-01

    Full Text Available Heavy metal contamination has been recognized as a major public health risk, particularly in developing countries and their toxicological manifestations are well known. Conventional remediation strategies are either expensive or they generate toxic by-products, which adversely affect the environment. Therefore, necessity for an environmentally safe strategy motivates interest towards biological techniques. One of such most profoundly driven approach in recent times is biosorption through microbial biomass and their products. Extracellular polymeric substances are such complex blend of high molecular weight microbial (prokaryotic and eukaryotic biopolymers. They are mainly composed of proteins, polysaccharides, uronic acids, humic substances, lipids etc. One of its essential constituent is the exopolysaccharide (EPS released out of self defense against harsh conditions of starvation, pH and temperature, hence it displays exemplary physiological, rheological and physio-chemical properties. Its net anionic makeup allows the biopolymer to effectively sequester positively charged heavy metal ions. The polysaccharide has been expounded deeply in this article with reference to its biosynthesis and emphasizes heavy metal sorption abilities of polymer in terms of mechanism of action and remediation. It reports current investigation and strategic advancements in dealing bacterial cells and their EPS in diverse forms – mixed culture EPS, single cell EPS, live, dead or immobilized EPS. A significant scrutiny is also involved highlighting the existing challenges that still lie in the path of commercialization. The article enlightens the potential of EPS to bring about bio-detoxification of heavy metal contaminated terrestrial and aquatic systems in highly sustainable, economic and eco-friendly manner.

  9. Ecological and genetic factors influencing the transition between host-use strategies in sympatric Heliconius butterflies.

    Science.gov (United States)

    Merrill, R M; Naisbit, R E; Mallet, J; Jiggins, C D

    2013-09-01

    Shifts in host-plant use by phytophagous insects have played a central role in their diversification. Evolving host-use strategies will reflect a trade-off between selection pressures. The ecological niche of herbivorous insects is partitioned along several dimensions, and if populations remain in contact, recombination will break down associations between relevant loci. As such, genetic architecture can profoundly affect the coordinated divergence of traits and subsequently the ability to exploit novel habitats. The closely related species Heliconius cydno and H. melpomene differ in mimetic colour pattern, habitat and host-plant use. We investigate the selection pressures and genetic basis underlying host-use differences in these two species. Host-plant surveys reveal that H. melpomene specializes on a single species of Passiflora. This is also true for the majority of other Heliconius species in secondary growth forest at our study site, as expected under a model of interspecific competition. In contrast, H. cydno, which uses closed-forest habitats where both Heliconius and Passiflora are less common, appears not to be restricted by competition and uses a broad selection of the available Passiflora. However, other selection pressures are likely involved, and field experiments reveal that early larval survival of both butterfly species is highest on Passiflora menispermifolia, but most markedly so for H. melpomene, the specialist on that host. Finally, we demonstrate an association between host-plant acceptance and colour pattern amongst interspecific hybrids, suggesting that major loci underlying these important ecological traits are physically linked in the genome. Together, our results reveal ecological and genetic associations between shifts in habitat, host use and mimetic colour pattern that have likely facilitated both speciation and coexistence. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  10. The Worldviews Network: Innovative Strategies for Increasing Climate and Ecological Literacy in Your Community

    Science.gov (United States)

    Connolly, R.; Yu, K.; McConville, D.; Sickler, J.; "Irving, Lindsay", L. S.; Gardiner, N.; Hamilton, H.

    2011-12-01

    Informal science Institutions (ISI) are in the unique position to convene and support community dialogues surrounding local ecological impacts of global change. The Worldviews Network-a collaboration between museums, scientists, and community-based organizations-is developing and testing innovative approaches for promoting and encouraging ecological literacy with the American public. In this session, we will share strategies for sparking and sustaining dialogue and action in local communities through high-impact visual presentations and real-world examples of successful projects that are increasing the healthy functioning of regional and global ecosystems. Educating the public about interconnected global change issues can be a daunting task. ISIs can help communities by facilitating dialogues about realistic and regionally relevant approaches for systemically addressing global challenges. Managing the complexity of these challenges requires going far beyond the standard prescriptions for behavior change; it requires inspiring participants with positive examples of system-wide solutions as well as actively involving the audience in scientifically informed design processes. This session will demonstrate how you can implement and sustain these community dialogues, using real-world examples from our partners' national events. We present visualization story templates and a model for facilitating dialogues that can be adapted at your institution. Based on video and written assessment feedback from visitors of our first Worldviews events, we will present initial evaluation findings about the impact that these strategies are having on our audiences and ISI partners. These findings show that engaging the public and NGO partners in sustainability and design dialogues is a powerful way to maintain the relevance of ISIs within their communities.

  11. Modeling economic implications of alternative treatment strategies for acute bacterial skin and skin structure infections.

    Science.gov (United States)

    Revankar, Nikhil; Ward, Alexandra J; Pelligra, Christopher G; Kongnakorn, Thitima; Fan, Weihong; LaPensee, Kenneth T

    2014-10-01

    The economic implications from the US Medicare perspective of adopting alternative treatment strategies for acute bacterial skin and skin structure infections (ABSSSIs) are substantial. The objective of this study is to describe a modeling framework that explores the impact of decisions related to both the location of care and switching to different antibiotics at discharge. A discrete event simulation (DES) was developed to model the treatment pathway of each patient through various locations (emergency department [ED], inpatient, and outpatient) and the treatments prescribed (empiric antibiotic, switching to a different antibiotic at discharge, or a second antibiotic). Costs are reported in 2012 USD. The mean number of days on antibiotic in a cohort assigned to a full course of vancomycin was 11.2 days, with 64% of the treatment course being administered in the outpatient setting. Mean total costs per patient were $8671, with inpatient care accounting for 58% of the costs accrued. The majority of outpatient costs were associated with parenteral administration rather than drug acquisition or monitoring. Scenarios modifying the treatment pathway to increase the proportion of patients receiving the first dose in the ED, and then managing them in the outpatient setting or prescribing an oral antibiotic at discharge to avoid the cost associated with administering parenteral therapy, therefore have a major impact and lower the typical cost per patient by 11-20%. Since vancomycin is commonly used as empiric therapy in clinical practice, based on these analyses, a shift in treatment practice could result in substantial savings from the Medicare perspective. The choice of antibiotic and location of care influence the costs and resource use associated with the management of ABSSSIs. The DES framework presented here can provide insight into the potential economic implications of decisions that modify the treatment pathway.

  12. Ecological dynamics of age selective harvesting of fish population: Maximum sustainable yield and its control strategy

    International Nuclear Information System (INIS)

    Jana, Debaldev; Agrawal, Rashmi; Upadhyay, Ranjit Kumar; Samanta, G.P.

    2016-01-01

    Highlights: • Age-selective harvesting of prey and predator are considered by multi-delayed prey-predator system. • System experiences stable coexistence to oscillatory mode and vice versa via Hopf-bifurcation depending upon the parametric restrictions. • MSY, bionomic equilibrium and optimal harvesting policy are also depending upon the age-selection of prey and predator. • All the analytic results are delay dependent. • Numerical examples support the analytical findings. - Abstract: Life history of ecological resource management and empirical studies are increasingly documenting the impact of selective harvesting process on the evolutionary stable strategy of both aquatic and terrestrial ecosystems. In the present study, the interaction between population and their independent and combined selective harvesting are framed by a multi-delayed prey-predator system. Depending upon the age selection strategy, system experiences stable coexistence to oscillatory mode and vice versa via Hopf-bifurcation. Economic evolution of the system which is mainly featured by maximum sustainable yield (MSY), bionomic equilibrium and optimal harvesting vary largely with the commensurate age selections of both population because equilibrium population abundance becomes age-selection dependent. Our study indicates that balance between harvesting delays and harvesting intensities should be maintained for better ecosystem management. Numerical examples support the analytical findings.

  13. Climate change adaptation strategies for federal forests of the Pacific Northwest, USA: ecological, policy, and socio-economic perspectives

    Science.gov (United States)

    Thomas A. Spies; Thomas W. Giesen; Frederick J. Swanson; Jerry F. Franklin; Denise Lach; K. Norman. Johnson

    2010-01-01

    Conserving biological diversity in a changing climate poses major challenges for land managers and society. Effective adaptive strategies for dealing with climate change require a socioecological systems perspective. We highlight some of the projected ecological responses to climate change in the Pacific Northwest, U.S.A and identify possible adaptive actions that...

  14. A systematic approach for watershed ecological restoration strategy making: An application in the Taizi River Basin in northern China.

    Science.gov (United States)

    Li, Mengdi; Fan, Juntao; Zhang, Yuan; Guo, Fen; Liu, Lusan; Xia, Rui; Xu, Zongxue; Wu, Fengchang

    2018-05-15

    Aiming to protect freshwater ecosystems, river ecological restoration has been brought into the research spotlight. However, it is challenging for decision makers to set appropriate objectives and select a combination of rehabilitation acts from numerous possible solutions to meet ecological, economic, and social demands. In this study, we developed a systematic approach to help make an optimal strategy for watershed restoration, which incorporated ecological security assessment and multi-objectives optimization (MOO) into the planning process to enhance restoration efficiency and effectiveness. The river ecological security status was evaluated by using a pressure-state-function-response (PSFR) assessment framework, and MOO was achieved by searching for the Pareto optimal solutions via Non-dominated Sorting Genetic Algorithm II (NSGA-II) to balance tradeoffs between different objectives. Further, we clustered the searched solutions into three types in terms of different optimized objective function values in order to provide insightful information for decision makers. The proposed method was applied in an example rehabilitation project in the Taizi River Basin in northern China. The MOO result in the Taizi River presented a set of Pareto optimal solutions that were classified into three types: I - high ecological improvement, high cost and high benefits solution; II - medial ecological improvement, medial cost and medial economic benefits solution; III - low ecological improvement, low cost and low economic benefits solution. The proposed systematic approach in our study can enhance the effectiveness of riverine ecological restoration project and could provide valuable reference for other ecological restoration planning. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Using diel movement behavior to infer foraging strategies related to ecological and social factors in elephants.

    Science.gov (United States)

    Polansky, Leo; Douglas-Hamilton, Iain; Wittemyer, George

    2013-01-01

    behavior. Beyond situations of contest competition, rank status appears to influence the extent to which individuals can modify their movement strategies across periods with differing forage availability. Large-scale spatiotemporal resource complexity not only impacts fine scale movement and optimal foraging strategies directly, but likely impacts rates of inter- and intra-specific interactions and competition resulting in socially based movement responses to ecological dynamics.

  16. Bacterial community composition and predicted functional ecology of sponges, sediment and seawater from the thousand islands reef complex, West Java, Indonesia.

    Science.gov (United States)

    de Voogd, Nicole J; Cleary, Daniel F R; Polónia, Ana R M; Gomes, Newton C M

    2015-04-01

    In the present study, we assessed the composition of Bacteria in four biotopes namely sediment, seawater and two sponge species (Stylissa massa and Xestospongia testudinaria) at four different reef sites in a coral reef ecosystem in West Java, Indonesia. In addition to this, we used a predictive metagenomic approach to estimate to what extent nitrogen metabolic pathways differed among bacterial communities from different biotopes. We observed marked differences in bacterial composition of the most abundant bacterial phyla, classes and orders among sponge species, water and sediment. Proteobacteria were by far the most abundant phylum in terms of both sequences and Operational Taxonomic Units (OTUs). Predicted counts for genes associated with the nitrogen metabolism suggested that several genes involved in the nitrogen cycle were enriched in sponge samples, including nosZ, nifD, nirK, norB and nrfA genes. Our data show that a combined barcoded pyrosequencing and predictive metagenomic approach can provide novel insights into the potential ecological functions of the microbial communities. Not only is this approach useful for our understanding of the vast microbial diversity found in sponges but also to understand the potential response of microbial communities to environmental change. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Ecology and biotechnological potential of bacterial community from three marine sponges of the coast of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    FÁBIO V. DE ARAÚJO

    2017-12-01

    Full Text Available ABSTRACT Marine sponges has been a large reservoir of microbial diversity, with the presence of many species specific populations as well as producing biologically active compounds, which has attracted great biotechnological interest. In order to verify the influence of the environment in the composition of the bacterial community present in marine sponges and biotechnological potential of bacteria isolated from these organisms, three species of sponges and the waters surrounding them were collected in different beaches of Rio de Janeiro, Brazil. The profile of the bacterial community present in sponges and water was obtained by PCR-DGGE technique and the biotechnological potential of the strains isolated by producing amylase, cellulase, protease and biosurfactants. The results showed that despite the influence of the environment in the composition of the microbial community, studied marine sponges shown to have specific bacterial populations, with some, showing potential in the production of substances of biotechnological applications.

  18. Approach and Strategy for Performing Ecological Risk Assessments for the Department of Energy Oak Ridge Field Office Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II

    1992-01-01

    This technical memorandum provides guidance for planning and performing ecological risk assessments (ERAs) on the Oak Ridge Reservation (ORR). This work was performed under Work Breakdown Structure 1.4.12.2.3.04.07.02 (Activity Data Sheet 8304) and meets an Environmental Restoration Program milestone for FY 95. The strategy discussed in this report is consistent with the overall strategy for site management and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) compliance developed for the ORR and relevant U.S. Environmental Protection Agency documents and guidance. The general approach and strategy presented herein was developed for the ORR, but it could be applicable to other complex CERCLA sites that possess significant ecological resources.

  19. New Weapons to Fight Old Enemies: Novel Strategies for the (Bio)control of Bacterial Biofilms in the Food Industry.

    Science.gov (United States)

    Coughlan, Laura M; Cotter, Paul D; Hill, Colin; Alvarez-Ordóñez, Avelino

    2016-01-01

    Biofilms are microbial communities characterized by their adhesion to solid surfaces and the production of a matrix of exopolymeric substances, consisting of polysaccharides, proteins, DNA and lipids, which surround the microorganisms lending structural integrity and a unique biochemical profile to the biofilm. Biofilm formation enhances the ability of the producer/s to persist in a given environment. Pathogenic and spoilage bacterial species capable of forming biofilms are a significant problem for the healthcare and food industries, as their biofilm-forming ability protects them from common cleaning processes and allows them to remain in the environment post-sanitation. In the food industry, persistent bacteria colonize the inside of mixing tanks, vats and tubing, compromising food safety and quality. Strategies to overcome bacterial persistence through inhibition of biofilm formation or removal of mature biofilms are therefore necessary. Current biofilm control strategies employed in the food industry (cleaning and disinfection, material selection and surface preconditioning, plasma treatment, ultrasonication, etc.), although effective to a certain point, fall short of biofilm control. Efforts have been explored, mainly with a view to their application in pharmaceutical and healthcare settings, which focus on targeting molecular determinants regulating biofilm formation. Their application to the food industry would greatly aid efforts to eradicate undesirable bacteria from food processing environments and, ultimately, from food products. These approaches, in contrast to bactericidal approaches, exert less selective pressure which in turn would reduce the likelihood of resistance development. A particularly interesting strategy targets quorum sensing systems, which regulate gene expression in response to fluctuations in cell-population density governing essential cellular processes including biofilm formation. This review article discusses the problems associated

  20. New weapons to fight old enemies: novel strategies for the (biocontrol of bacterial biofilms in the food industry

    Directory of Open Access Journals (Sweden)

    Laura Maria Coughlan

    2016-10-01

    Full Text Available Biofilms are microbial communities characterized by their adhesion to solid surfaces and the production of a matrix of exopolymeric substances (EPS, consisting of polysaccharides, proteins, DNA and lipids, which surround the microorganisms lending structural integrity and a unique biochemical profile to the biofilm. Biofilm formation enhances the ability of the producer/s to persist in a given environment. Pathogenic and spoilage bacterial species capable of forming biofilms are a significant problem for the healthcare and food industries, as their biofilm-forming ability protects them from common cleaning processes and allows them to remain in the environment post-sanitation. In the food industry, persistent bacteria colonize the inside of mixing tanks, vats and tubing, compromising food safety and quality. Strategies to overcome bacterial persistence through inhibition of biofilm formation or removal of mature biofilms are therefore necessary. Current biofilm control strategies employed in the food industry (cleaning and disinfection, material selection and surface preconditioning, plasma treatment, ultrasonication, etc., although effective to a certain point, fall short of biofilm control. Efforts have been explored, mainly with a view to their application in pharmaceutical and healthcare settings, which focus on targeting molecular determinants regulating biofilm formation. Their application to the food industry would greatly aid efforts to eradicate undesirable bacteria from food processing environments and, ultimately, from food products. These approaches, in contrast to bactericidal approaches, exert less selective pressure which in turn would reduce the likelihood of resistance development. A particularly interesting strategy targets quorum sensing systems, which regulate gene expression in response to fluctuations in cell-population density governing essential cellular processes including biofilm formation. This review article discusses

  1. Integrated metagenomics and molecular ecological network analysis of bacterial community composition during the phytoremediation of cadmium-contaminated soils by bioenergy crops.

    Science.gov (United States)

    Chen, Zhaojin; Zheng, Yuan; Ding, Chuanyu; Ren, Xuemin; Yuan, Jian; Sun, Feng; Li, Yuying

    2017-11-01

    Two energy crops (maize and soybean) were used in the remediation of cadmium-contaminated soils. These crops were used because they are fast growing, have a large biomass and are good sources for bioenergy production. The total accumulation of cadmium in maize and soybean plants was 393.01 and 263.24μg pot -1 , respectively. The rhizosphere bacterial community composition was studied by MiSeq sequencing. Phylogenetic analysis was performed using 16S rRNA gene sequences. The rhizosphere bacteria were divided into 33 major phylogenetic groups according to phyla. The dominant phylogenetic groups included Proteobacteria, Acidobacteria, Actinobacteria, Gemmatimonadetes, and Bacteroidetes. Based on principal component analysis (PCA) and unweighted pair group with arithmetic mean (UPGMA) analysis, we found that the bacterial community was influenced by cadmium addition and bioenergy cropping. Three molecular ecological networks were constructed for the unplanted, soybean- and maize-planted bacterial communities grown in 50mgkg -1 cadmium-contaminated soils. The results indicated that bioenergy cropping increased the complexity of the bacterial community network as evidenced by a higher total number of nodes, the average geodesic distance (GD), the modularity and a shorter geodesic distance. Proteobacteria and Acidobacteria were the keystone bacteria connecting different co-expressed operational taxonomic units (OTUs). The results showed that bioenergy cropping altered the topological roles of individual OTUs and keystone populations. This is the first study to reveal the effects of bioenergy cropping on microbial interactions in the phytoremediation of cadmium-contaminated soils by network reconstruction. This method can greatly enhance our understanding of the mechanisms of plant-microbe-metal interactions in metal-polluted ecosystems. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Strategies used for genetically modifying bacterial genome: ite-directed mutagenesis, gene inactivation, and gene over-expression*

    Science.gov (United States)

    Xu, Jian-zhong; Zhang, Wei-guo

    2016-01-01

    With the availability of the whole genome sequence of Escherichia coli or Corynebacterium glutamicum, strategies for directed DNA manipulation have developed rapidly. DNA manipulation plays an important role in understanding the function of genes and in constructing novel engineering bacteria according to requirement. DNA manipulation involves modifying the autologous genes and expressing the heterogenous genes. Two alternative approaches, using electroporation linear DNA or recombinant suicide plasmid, allow a wide variety of DNA manipulation. However, the over-expression of the desired gene is generally executed via plasmid-mediation. The current review summarizes the common strategies used for genetically modifying E. coli and C. glutamicum genomes, and discusses the technical problem of multi-layered DNA manipulation. Strategies for gene over-expression via integrating into genome are proposed. This review is intended to be an accessible introduction to DNA manipulation within the bacterial genome for novices and a source of the latest experimental information for experienced investigators. PMID:26834010

  3. Development and validation of an rDNA operon based primer walking strategy applicable to de novo bacterial genome finishing.

    Directory of Open Access Journals (Sweden)

    Alexander William Eastman

    2015-01-01

    Full Text Available Advances in sequencing technology have drastically increased the depth and feasibility of bacterial genome sequencing. However, little information is available that details the specific techniques and procedures employed during genome sequencing despite the large numbers of published genomes. Shotgun approaches employed by second-generation sequencing platforms has necessitated the development of robust bioinformatics tools for in silico assembly, and complete assembly is limited by the presence of repetitive DNA sequences and multi-copy operons. Typically, re-sequencing with multiple platforms and laborious, targeted Sanger sequencing are employed to finish a draft bacterial genome. Here we describe a novel strategy based on the identification and targeted sequencing of repetitive rDNA operons to expedite bacterial genome assembly and finishing. Our strategy was validated by finishing the genome of Paenibacillus polymyxa strain CR1, a bacterium with potential in sustainable agriculture and bio-based processes. An analysis of the 38 contigs contained in the P. polymyxa strain CR1 draft genome revealed 12 repetitive rDNA operons with varied intragenic and flanking regions of variable length, unanimously located at contig boundaries and within contig gaps. These highly similar but not identical rDNA operons were experimentally verified and sequenced simultaneously with multiple, specially designed primer sets. This approach also identified and corrected significant sequence rearrangement generated during the initial in silico assembly of sequencing reads. Our approach reduces the required effort associated with blind primer walking for contig assembly, increasing both the speed and feasibility of genome finishing. Our study further reinforces the notion that repetitive DNA elements are major limiting factors for genome finishing. Moreover, we provided a step-by-step workflow for genome finishing, which may guide future bacterial genome finishing

  4. The construction strategy and measures for ecological analysis of China's ports

    Science.gov (United States)

    Zhang, Lu; Zhao, Junjie; Shou, Youping; Wang, Ning; Qiao, Jianzhe; Tian, Mingjing

    2018-04-01

    The Port is an important transport hub, one of the important infrastructure of the national economy, the corresponding regional development has a great role in promoting.The construction of the port has been developed rapidly, but it has also brought about more serious environmental problems. Therefore, this paper discusses the nature of ecological ports, summarized the experience of ecological protection measures on the international advanced ports and port construction ecology. The central idea is to explore the construction of ecological port ideas and development countermeasures.

  5. Ecology and Evolution as Targets: the Need for Novel Eco-Evo Drugs and Strategies To Fight Antibiotic Resistance▿†

    Science.gov (United States)

    Baquero, Fernando; Coque, Teresa M.; de la Cruz, Fernando

    2011-01-01

    In recent years, the explosive spread of antibiotic resistance determinants among pathogenic, commensal, and environmental bacteria has reached a global dimension. Classical measures trying to contain or slow locally the progress of antibiotic resistance in patients on the basis of better antibiotic prescribing policies have clearly become insufficient at the global level. Urgent measures are needed to directly confront the processes influencing antibiotic resistance pollution in the microbiosphere. Recent interdisciplinary research indicates that new eco-evo drugs and strategies, which take ecology and evolution into account, have a promising role in resistance prevention, decontamination, and the eventual restoration of antibiotic susceptibility. This minireview summarizes what is known and what should be further investigated to find drugs and strategies aiming to counteract the “four P's,” penetration, promiscuity, plasticity, and persistence of rapidly spreading bacterial clones, mobile genetic elements, or resistance genes. The term “drug” is used in this eco-evo perspective as a tool to fight resistance that is able to prevent, cure, or decrease potential damage caused by antibiotic resistance, not necessarily only at the individual level (the patient) but also at the ecological and evolutionary levels. This view offers a wealth of research opportunities for science and technology and also represents a large adaptive challenge for regulatory agencies and public health officers. Eco-evo drugs and interventions constitute a new avenue for research that might influence not only antibiotic resistance but the maintenance of a healthy interaction between humans and microbial systems in a rapidly changing biosphere. PMID:21576439

  6. Pneumococcal conjugate vaccines; impact on nasopharyngeal bacterial carriage and optimizing vaccination strategies

    NARCIS (Netherlands)

    Spijkerman, J.

    2013-01-01

    The aim of this thesis was to first assess nasopharyngeal bacterial carriage to evaluate population effects after introduction of PCV7 in the NIP in 2006 and to assess the potential impact of PCV10 as introduced in 2011 on carriage of NTHi in a randomized trial (Part One) and second, to assess

  7. A Bioinformatic Strategy for the Detection, Classification and Analysis of Bacterial Autotransporters

    Science.gov (United States)

    Celik, Nermin; Webb, Chaille T.; Leyton, Denisse L.; Holt, Kathryn E.; Heinz, Eva; Gorrell, Rebecca; Kwok, Terry; Naderer, Thomas; Strugnell, Richard A.; Speed, Terence P.; Teasdale, Rohan D.; Likić, Vladimir A.; Lithgow, Trevor

    2012-01-01

    Autotransporters are secreted proteins that are assembled into the outer membrane of bacterial cells. The passenger domains of autotransporters are crucial for bacterial pathogenesis, with some remaining attached to the bacterial surface while others are released by proteolysis. An enigma remains as to whether autotransporters should be considered a class of secretion system, or simply a class of substrate with peculiar requirements for their secretion. We sought to establish a sensitive search protocol that could identify and characterize diverse autotransporters from bacterial genome sequence data. The new sequence analysis pipeline identified more than 1500 autotransporter sequences from diverse bacteria, including numerous species of Chlamydiales and Fusobacteria as well as all classes of Proteobacteria. Interrogation of the proteins revealed that there are numerous classes of passenger domains beyond the known proteases, adhesins and esterases. In addition the barrel-domain-a characteristic feature of autotransporters-was found to be composed from seven conserved sequence segments that can be arranged in multiple ways in the tertiary structure of the assembled autotransporter. One of these conserved motifs overlays the targeting information required for autotransporters to reach the outer membrane. Another conserved and diagnostic motif maps to the linker region between the passenger domain and barrel-domain, indicating it as an important feature in the assembly of autotransporters. PMID:22905239

  8. Poverty alleviation strategies in eastern China lead to critical ecological dynamics

    DEFF Research Database (Denmark)

    Zhang, Ke; Dearing, John A.; Dawson, Terence P.

    2015-01-01

    the likelihood of sustainable agriculture or ecological collapse.We show how the analyses of 55 time-series of social, economic and ecological conditions can provide an evolutionary perspective for the modern Lower Yangtze River Basin region since the 1950s with powerful insights about the sustainability...

  9. Ecological models in support of regulatory risk assessments of pesticides: developing a strategy for the future.

    Science.gov (United States)

    Forbes, Valery E; Hommen, Udo; Thorbek, Pernille; Heimbach, Fred; Van den Brink, Paul J; Wogram, Jörn; Thulke, Hans-Hermann; Grimm, Volker

    2009-01-01

    This brief communication reports on the main findings of the LEMTOX workshop, held from 9 to 12 September 2007, at the Helmholtz Centre for Environmental Research (UFZ) in Leipzig, Germany. The workshop brought together a diverse group of stakeholders from academia, regulatory authorities, contract research organizations, and industry, representing Europe, the United States, and Asia, to discuss the role of ecological modeling in risk assessments of pesticides, particularly under the European regulatory framework. The following questions were addressed: What are the potential benefits of using ecological models in pesticide registration and risk assessment? What obstacles prevent ecological modeling from being used routinely in regulatory submissions? What actions are needed to overcome the identified obstacles? What recommendations should be made to ensure good modeling practice in this context? The workshop focused exclusively on population models, and discussion was focused on those categories of population models that link effects on individuals (e.g., survival, growth, reproduction, behavior) to effects on population dynamics. The workshop participants concluded that the overall benefits of ecological modeling are that it could bring more ecology into ecological risk assessment, and it could provide an excellent tool for exploring the importance of, and interactions among, ecological complexities. However, there are a number of challenges that need to be overcome before such models will receive wide acceptance for pesticide risk assessment, despite having been used extensively in other contexts (e.g., conservation biology). The need for guidance on Good Modeling Practice (on model development, analysis, interpretation, evaluation, documentation, and communication), as well as the need for case studies that can be used to explore the added value of ecological models for risk assessment, were identified as top priorities. Assessing recovery potential of exposed

  10. Heterologous Expression of Toxins from Bacterial Toxin-Antitoxin Systems in Eukaryotic Cells: Strategies and Applications

    Directory of Open Access Journals (Sweden)

    Chew Chieng Yeo

    2016-02-01

    Full Text Available Toxin-antitoxin (TA systems are found in nearly all prokaryotic genomes and usually consist of a pair of co-transcribed genes, one of which encodes a stable toxin and the other, its cognate labile antitoxin. Certain environmental and physiological cues trigger the degradation of the antitoxin, causing activation of the toxin, leading either to the death or stasis of the host cell. TA systems have a variety of functions in the bacterial cell, including acting as mediators of programmed cell death, the induction of a dormant state known as persistence and the stable maintenance of plasmids and other mobile genetic elements. Some bacterial TA systems are functional when expressed in eukaryotic cells and this has led to several innovative applications, which are the subject of this review. Here, we look at how bacterial TA systems have been utilized for the genetic manipulation of yeasts and other eukaryotes, for the containment of genetically modified organisms, and for the engineering of high expression eukaryotic cell lines. We also examine how TA systems have been adopted as an important tool in developmental biology research for the ablation of specific cells and the potential for utility of TA systems in antiviral and anticancer gene therapies.

  11. Heterologous Expression of Toxins from Bacterial Toxin-Antitoxin Systems in Eukaryotic Cells: Strategies and Applications

    Science.gov (United States)

    Yeo, Chew Chieng; Abu Bakar, Fauziah; Chan, Wai Ting; Espinosa, Manuel; Harikrishna, Jennifer Ann

    2016-01-01

    Toxin-antitoxin (TA) systems are found in nearly all prokaryotic genomes and usually consist of a pair of co-transcribed genes, one of which encodes a stable toxin and the other, its cognate labile antitoxin. Certain environmental and physiological cues trigger the degradation of the antitoxin, causing activation of the toxin, leading either to the death or stasis of the host cell. TA systems have a variety of functions in the bacterial cell, including acting as mediators of programmed cell death, the induction of a dormant state known as persistence and the stable maintenance of plasmids and other mobile genetic elements. Some bacterial TA systems are functional when expressed in eukaryotic cells and this has led to several innovative applications, which are the subject of this review. Here, we look at how bacterial TA systems have been utilized for the genetic manipulation of yeasts and other eukaryotes, for the containment of genetically modified organisms, and for the engineering of high expression eukaryotic cell lines. We also examine how TA systems have been adopted as an important tool in developmental biology research for the ablation of specific cells and the potential for utility of TA systems in antiviral and anticancer gene therapies. PMID:26907343

  12. Approach and strategy for performing ecological risk assessments for the Department of Energy Oak Ridge Field Office Environmental Restoration Program

    International Nuclear Information System (INIS)

    Suter, G.W. II; Redfearn, A.; White, R.K.; Shaw, R.A.

    1992-07-01

    This document is intended to supplement exiting US Environmental Protection Agency (EPA) guidance for ecological risk assessment at hazardous waste sites by providing guidance that is more specific and more tailored to US Department of Energy sites than the guidance available from the EPA. However, it is a conceptual strategy document and does not include specific guidance on data, assumptions, and models. That detailed guidance is under development and will be presented in subsequent documents. Ecological risk assessments are equal to human health risk assessments in regulatory importance and can use many of the same data and some of the same estimation methods. However, they also have peculiar data needs and methods. Ecological risk assessments begin with an initial scoping phase, termed hazard definition, that characterizes the sources, the potentially environment, and the assessment endpoints. In the subsequent measurement and estimation phase, in which data are obtained concerning source of the endpoint biota to the contaminants and the effects of those exposures, and assumptions and models are used to relate the data to the desired exposure and effects parameters. Finally, in an integration phase, termed risk characterization, the various exposure and effects estimates are combined to infer the existence, cause, magnitude, and extent of effects of contaminants on the ecological endpoints. This phase is much more complicated for ecological risk assessments than for human health assessments because more types of data are available. Ecological risk assessments estimate effects using laboratory toxicity test results, like human health assessments, but also use results of ambient toxicity tests and biological surveys

  13. Cellulosic hydrogen production with a sequencing bacterial hydrolysis and dark fermentation strategy.

    Science.gov (United States)

    Lo, Yung-Chung; Bai, Ming-Der; Chen, Wen-Ming; Chang, Jo-Shu

    2008-11-01

    In this study, cellulose hydrolysis activity of two mixed bacterial consortia (NS and QS) was investigated. Combination of NS culture and BHM medium exhibited better hydrolytic activity under the optimal condition of 35 degrees C, initial pH 7.0, and 100rpm agitation. The NS culture could hydrolyze carboxymethyl cellulose (CMC), rice husk, bagasse and filter paper, among which CMC gave the best hydrolysis performance. The CMC hydrolysis efficiency increased with increasing CMC concentration from 5 to 50g/l. With a CMC concentration of 10g/l, the total reducing sugar (RS) production and the RS producing rate reached 5531.0mg/l and 92.9mg/l/h, respectively. Furthermore, seven H2-producing bacterial isolates (mainly Clostridium species) were used to convert the cellulose hydrolysate into H2 energy. With an initial RS concentration of 0.8g/l, the H2 production and yield was approximately 23.8ml/l and 1.21mmol H2/g RS (0.097mmol H2/g cellulose), respectively.

  14. CMEIAS-Aided Microscopy of the Spatial Ecology of Individual Bacterial Interactions Involving Cell-to-Cell Communication within Biofilms

    Directory of Open Access Journals (Sweden)

    Frank B. Dazzo

    2012-05-01

    Full Text Available This paper describes how the quantitative analytical tools of CMEIAS image analysis software can be used to investigate in situ microbial interactions involving cell-to-cell communication within biofilms. Various spatial pattern analyses applied to the data extracted from the 2-dimensional coordinate positioning of individual bacterial cells at single-cell resolution indicate that microbial colonization within natural biofilms is not a spatially random process, but rather involves strong positive interactions between communicating cells that influence their neighbors’ aggregated colonization behavior. Geostatistical analysis of the data provide statistically defendable estimates of the micrometer scale and interpolation maps of the spatial heterogeneity and local intensity at which these microbial interactions autocorrelate with their spatial patterns of distribution. Including in situ image analysis in cell communication studies fills an important gap in understanding the spatially dependent microbial ecophysiology that governs the intensity of biofilm colonization and its unique architecture.

  15. Ecology, economics and political will: the vicissitudes of malaria strategies in Asia.

    Science.gov (United States)

    Kidson, C; Indaratna, K

    1998-06-01

    The documented history of malaria in parts of Asia goes back more than 2,000 years, during which the disease has been a major player on the socioeconomic stage in many nation states as they waxed and waned in power and prosperity. On a much shorter time scale, the last half century has seen in microcosm a history of large fluctuations in endemicity and impact of malaria across the spectrum of rice fields and rain forests, mountains and plains that reflect the vast ecological diversity inhabited by this majority aggregation of mankind. That period has seen some of the most dramatic changes in social and economic structure, in population size, density and mobility, and in political structure in history: all have played a part in the changing face of malaria in this extensive region of the world. While the majority of global malaria cases currently reside in Africa, greater numbers inhabited Asia earlier this century before malaria programs savored significant success, and now Asia harbors a global threat in the form of the epicenter of multidrug resistant Plasmodium falciparum which is gradually encompassing the tropical world. The latter reflects directly the vicissitudes of economic change over recent decades, particularly the mobility of populations in search of commerce, trade and personal fortunes, or caught in the misfortunes of physical conflicts. The period from the 1950s to the 1990s has witnessed near "eradication" followed by resurgence of malaria in Sri Lanka, control and resurgence in India, the influence of war and postwar instability on drug resistance in Cambodia, increase in severe and cerebral malaria in Myanmar during prolonged political turmoil, the essential disappearance of the disease from all but forested border areas of Thailand where it remains for the moment intractable, the basic elimination of vivax malaria from many provinces of central China. Both positive and negative experiences have lessons to teach in the debate between eradication

  16. Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage.

    Science.gov (United States)

    Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Desmonts, Marie Hélène; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

    2015-05-01

    The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota.

  17. Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage

    Science.gov (United States)

    Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Hélène Desmonts, Marie; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

    2015-01-01

    The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota. PMID:25333463

  18. Origins of altruism diversity I: The diverse ecological roles of altruistic strategies and their evolutionary responses to local competition.

    Science.gov (United States)

    Van Dyken, J David; Wade, Michael J

    2012-08-01

    Nature abounds with a rich variety of altruistic strategies, including public resource enhancement, resource provisioning, communal foraging, alarm calling, and nest defense. Yet, despite their vastly different ecological roles, current theory typically treats diverse altruistic traits as being favored under the same general conditions. Here, we introduce greater ecological realism into social evolution theory and find evidence of at least four distinct modes of altruism. Contrary to existing theory, we find that altruistic traits contributing to "resource-enhancement" (e.g., siderophore production, provisioning, agriculture) and "resource-efficiency" (e.g., pack hunting, communication) are most strongly favored when there is strong local competition. These resource-based modes of helping are "K-strategies" that increase a social group's growth yield, and should characterize species with scarce resources and/or high local crowding caused by low mortality, high fecundity, and/or mortality occurring late in the process of resource-acquisition. The opposite conditions, namely weak local competition (abundant resource, low crowding), favor survival (e.g., nest defense) and fecundity (e.g., nurse workers) altruism, which are "r-strategies" that increase a social group's growth rate. We find that survival altruism is uniquely favored by a novel evolutionary force that we call "sunk cost selection." Sunk cost selection favors helping that prevents resources from being wasted on individuals destined to die before reproduction. Our results contribute to explaining the observed natural diversity of altruistic strategies, reveal the necessary connection between the evolution and the ecology of sociality, and correct the widespread but inaccurate view that local competition uniformly impedes the evolution of altruism. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  19. Poverty alleviation strategies in eastern China lead to critical ecological dynamics.

    Science.gov (United States)

    Zhang, Ke; Dearing, John A; Dawson, Terence P; Dong, Xuhui; Yang, Xiangdong; Zhang, Weiguo

    2015-02-15

    Poverty alleviation linked to agricultural intensification has been achieved in many regions but there is often only limited understanding of the impacts on ecological dynamics. A central need is to observe long term changes in regulating and supporting services as the basis for assessing the likelihood of sustainable agriculture or ecological collapse. We show how the analyses of 55 time-series of social, economic and ecological conditions can provide an evolutionary perspective for the modern Lower Yangtze River Basin region since the 1950s with powerful insights about the sustainability of modern ecosystem services. Increasing trends in provisioning ecosystem services within the region over the past 60 years reflect economic growth and successful poverty alleviation but are paralleled by steep losses in a range of regulating ecosystem services mainly since the 1980s. Increasing connectedness across the social and ecological domains after 1985 points to a greater uniformity in the drivers of the rural economy. Regime shifts and heightened levels of variability since the 1970s in local ecosystem services indicate progressive loss of resilience across the region. Of special concern are water quality services that have already passed critical transitions in several areas. Viewed collectively, our results suggest that the regional social-ecological system passed a tipping point in the late 1970s and is now in a transient phase heading towards a new steady state. However, the long-term relationship between economic growth and ecological degradation shows no sign of decoupling as demanded by the need to reverse an unsustainable trajectory. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  20. [Strategy for choosing antibiotics for treating bacterial infections associated with chronic tick-borne encephalitis].

    Science.gov (United States)

    Malenko, G V; Pogodina, V V; Frolova, M P; Ivannikova, T A

    1996-01-01

    The capacity of wide-spectrum antibiotics kefzol and ristomycin to activate the persisting tick-borne encephalitis (TBE) virus and cause an exacerbation of chronic process was investigated in Syrian hamsters in whom a prolonged (77 to 270 days) persistent TBE infection was induced by three TBE strains: Vasilchenko, V-383, and 205. The degree of antibiotic-induced activation was assessed using the criteria characterizing the reproduction and peculiarities of persisting TBE virus, immunodepression, and morphologic changes in the central nervous system. Effects of kefzol and ristomycin were compared with those of 8 antibiotics studied previously. Ristomycin, levomycetin (chloramphycin), penicillin, ampicillin (ampital), and levoridan were referred to drugs devoid of evident provoking effect. Kefzol (cefamezin), florimycin (viomycin), and kanamycin (kanamytrex) were characterized as weak activators and streptomycin and tetracycline as potent activators of the persisting TBE virus. These data may be used when selecting alternative agents for therapy of secondary bacterial infections concomitant with TBE.

  1. Ecological strategies for long-term sustainability of the Malaysian ricefield agroecosystem

    International Nuclear Information System (INIS)

    Mashhor Mansor

    2002-01-01

    Ecological concepts should be imposed in ricefield agroecosystem so that a long-term sustainability as well as a sound environmental condition could be achieved. Although several problems are envisaged, thus can be overcome by adopting various techniques which are based on ecological principles. Fundamental issues which involve biodiversity, environment and economic activities should be addressed. In the ricefield agroecosystem the water regime also plays a major role particularly in determining the temporal aspects of the ricefield niche. Different seasons in this case, the dry and wet can have different types of food webs. (Author)

  2. Inhibitor design strategy based on an enzyme structural flexibility: a case of bacterial MurD ligase.

    Science.gov (United States)

    Perdih, Andrej; Hrast, Martina; Barreteau, Hélène; Gobec, Stanislav; Wolber, Gerhard; Solmajer, Tom

    2014-05-27

    Increasing bacterial resistance to available antibiotics stimulated the discovery of novel efficacious antibacterial agents. The biosynthesis of the bacterial peptidoglycan, where the MurD enzyme is involved in the intracellular phase of the UDP-MurNAc-pentapeptide formation, represents a collection of highly selective targets for novel antibacterial drug design. In our previous computational studies, the C-terminal domain motion of the MurD ligase was investigated using Targeted Molecular Dynamic (TMD) simulation and the Off-Path Simulation (OPS) technique. In this study, we present a drug design strategy using multiple protein structures for the identification of novel MurD ligase inhibitors. Our main focus was the ATP-binding site of the MurD enzyme. In the first stage, three MurD protein conformations were selected based on the obtained OPS/TMD data as the initial criterion. Subsequently, a two-stage virtual screening approach was utilized combining derived structure-based pharmacophores with molecular docking calculations. Selected compounds were then assayed in the established enzyme binding assays, and compound 3 from the aminothiazole class was discovered to act as a dual MurC/MurD inhibitor in the micomolar range. A steady-state kinetic study was performed on the MurD enzyme to provide further information about the mechanistic aspects of its inhibition. In the final stage, all used conformations of the MurD enzyme with compound 3 were simulated in classical molecular dynamics (MD) simulations providing atomistic insights of the experimental results. Overall, the study depicts several challenges that need to be addressed when trying to hit a flexible moving target such as the presently studied bacterial MurD enzyme and show the possibilities of how computational tools can be proficiently used at all stages of the drug discovery process.

  3. Program on ecosystem change and society: An international research strategy for integrated social-ecological systems

    NARCIS (Netherlands)

    Carpenter, S.R.; Folke, C.; Norström, A.V.; Olsson, O.; Schultz, L.; Agarwal, B.; Balvanera, P.; Campbell, B.; Castilla, J.C.; Cramer, W.; DeFries, R.; Eyzaguirre, P.; Hughes, T.P.; Polasky, S.; Sanusi, Z.A.; Scholes, R.J.; Spierenburg, M.J.

    2012-01-01

    The Program on Ecosystem Change and Society (PECS), a new initiative within the ICSU global change programs, aims to integrate research on the stewardship of social-ecological systems, the services they generate, and the relationships among natural capital, human wellbeing, livelihoods, inequality

  4. Program on ecosystem change and society: an international research strategy for integrated social–ecological systems

    NARCIS (Netherlands)

    Carpenter, S.R; Folke, C.; Nordström, A.; Olsson, O.; Schultz, L.; Agarwal, B.; Balvanera, P.; Campbell, B.; Castilla, J.C.; Cramer, W.; DeFries, R.; Eyzaguirre, P.; Hughes, T.P.; Polasky, S.; Sanusi, Z.; Spierenburg, M.J.

    2012-01-01

    The Program on Ecosystem Change and Society (PECS), a new initiative within the ICSU global change programs, aims to integrate research on the stewardship of social-ecological systems, the services they generate, and the relationships among natural capital, human wellbeing, livelihoods, inequality

  5. Ecological impacts and management strategies for western larch in the face of climate-change

    Science.gov (United States)

    Gerald E. Rehfeldt; Barry C. Jaquish

    2010-01-01

    Approximately 185,000 forest inventory and ecological plots from both USA and Canada were used to predict the contemporary distribution of western larch (Larix occidentalis Nutt.) from climate variables. The random forests algorithm, using an 8-variable model, produced an overall error rate of about 2.9 %, nearly all of which consisted of predicting presence at...

  6. A strategy for maximizing native plant material diversity for ecological restoration, germplasm conservation and genecology research

    Science.gov (United States)

    Berta Youtie; Nancy Shaw; Matt Fisk; Scott Jensen

    2012-01-01

    One of the most important steps in planning a restoration project is careful selection of ecologically adapted native plant material. As species-specific seed zone maps are not available for most species in the Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) ecoregion in the Great Basin, USA, we are employing a provisional seed zone map based on annual...

  7. Habitat Re-Creation (Ecological Restoration) as a Strategy for Conserving Insect Communities in Highly Fragmented Landscapes.

    Science.gov (United States)

    Shuey, John A

    2013-12-05

    Because of their vast diversity, measured by both numbers of species as well as life history traits, insects defy comprehensive conservation planning. Thus, almost all insect conservation efforts target individual species. However, serious insect conservation requires goals that are set at the faunal level and conservation success requires strategies that conserve intact communities. This task is complicated in agricultural landscapes by high levels of habitat fragmentation and isolation. In many regions, once widespread insect communities are now functionally trapped on islands of ecosystem remnants and subject to a variety of stressors associated with isolation, small population sizes and artificial population fragmentation. In fragmented landscapes ecological restoration can be an effective strategy for reducing localized insect extinction rates, but insects are seldom included in restoration design criteria. It is possible to incorporate a few simple conservation criteria into restoration designs that enhance impacts to entire insect communities. Restoration can be used as a strategy to address fragmentation threats to isolated insect communities if insect communities are incorporated at the onset of restoration planning. Fully incorporating insect communities into restoration designs may increase the cost of restoration two- to three-fold, but the benefits to biodiversity conservation and the ecological services provided by intact insect communities justify the cost.

  8. Approach and strategy for performing ecological risk assessments for the U.S. Department of Energy's Oak Ridge Reservation: 1994 revision

    International Nuclear Information System (INIS)

    Suter, G.W. II; Sample, B.E.; Jones, D.S.; Ashwood, T.L.

    1994-08-01

    This report provides guidance for planning and performing ecological risk assessments on the Oak Ridge Reservation (ORR). The tiered approach to ecological risk assessment has been implemented, generic conceptual models have been developed, and a general approach for developing ecological assessment endpoints and measurement endpoints has been agreed upon. The document also includes changes in terminology to agree with the terminology in the US Environmental Protection Agency's (EPA's) framework for ecological risk assessment. Although ecological risks are equal in regulatory importance to human health risks, formal procedures for ecological risk assessment are poorly developed. This report will provide specific guidance and promote the use of consistent approaches for ecological risk assessments at individual sites on the ORR. The strategy discussed in this report is consistent with the overall strategy for site management and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) compliance and with relevant EPA guidance. The general approach and strategy presented herein was developed for the ORR, but it should be applicable to other complex CERCLA sites that possess significant ecological resources

  9. Approach and strategy for performing ecological risk assessments for the U.S. Department of Energy`s Oak Ridge Reservation: 1994 revision

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II; Sample, B.E.; Jones, D.S.; Ashwood, T.L.

    1994-08-01

    This report provides guidance for planning and performing ecological risk assessments on the Oak Ridge Reservation (ORR). The tiered approach to ecological risk assessment has been implemented, generic conceptual models have been developed, and a general approach for developing ecological assessment endpoints and measurement endpoints has been agreed upon. The document also includes changes in terminology to agree with the terminology in the US Environmental Protection Agency`s (EPA`s) framework for ecological risk assessment. Although ecological risks are equal in regulatory importance to human health risks, formal procedures for ecological risk assessment are poorly developed. This report will provide specific guidance and promote the use of consistent approaches for ecological risk assessments at individual sites on the ORR. The strategy discussed in this report is consistent with the overall strategy for site management and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) compliance and with relevant EPA guidance. The general approach and strategy presented herein was developed for the ORR, but it should be applicable to other complex CERCLA sites that possess significant ecological resources.

  10. Multi-level Strategy for Identifying Proteasome-Catalyzed Spliced Epitopes Targeted by CD8+ T Cells during Bacterial Infection

    Directory of Open Access Journals (Sweden)

    Anouk C.M. Platteel

    2017-08-01

    Full Text Available Proteasome-catalyzed peptide splicing (PCPS generates peptides that are presented by MHC class I molecules, but because their identification is challenging, the immunological relevance of spliced peptides remains unclear. Here, we developed a reverse immunology-based multi-level approach to identify proteasome-generated spliced epitopes. Applying this strategy to a murine Listeria monocytogenes infection model, we identified two spliced epitopes within the secreted bacterial phospholipase PlcB that primed antigen-specific CD8+ T cells in L. monocytogenes-infected mice. While reacting to the spliced epitopes, these CD8+ T cells failed to recognize the non-spliced peptide parts in the context of their natural flanking sequences. Thus, we here show that PCPS expands the CD8+ T cell response against L. monocytogenes by exposing spliced epitopes on the cell surface. Moreover, our multi-level strategy opens up opportunities to systematically investigate proteins for spliced epitope candidates and thus strategies for immunotherapies or vaccine design.

  11. Bacterial Genetic Architecture of Ecological Interactions in Co-culture by GWAS-Taking Escherichia coli and Staphylococcus aureus as an Example.

    Science.gov (United States)

    He, Xiaoqing; Jin, Yi; Ye, Meixia; Chen, Nan; Zhu, Jing; Wang, Jingqi; Jiang, Libo; Wu, Rongling

    2017-01-01

    How a species responds to such a biotic environment in the community, ultimately leading to its evolution, has been a topic of intense interest to ecological evolutionary biologists. Until recently, limited knowledge was available regarding the genotypic changes that underlie phenotypic changes. Our study implemented GWAS (Genome-Wide Association Studies) to illustrate the genetic architecture of ecological interactions that take place in microbial populations. By choosing 45 such interspecific pairs of Escherichia coli and Staphylococcus aureus strains that were all genotyped throughout the entire genome, we employed Q-ROADTRIPS to analyze the association between single SNPs and microbial abundance measured at each time point for bacterial populations reared in monoculture and co-culture, respectively. We identified a large number of SNPs and indels across the genomes (35.69 G clean data of E. coli and 50.41 G of S. aureus ). We reported 66 and 111 SNPs that were associated with interaction in E. coli and S. aureus , respectively. 23 out of 66 polymorphic changes resulted in amino acid alterations.12 significant genes, such as murE, treA, argS , and relA , which were also identified in previous evolutionary studies. In S. aureus , 111 SNPs detected in coding sequences could be divided into 35 non-synonymous and 76 synonymous SNPs. Our study illustrated the potential of genome-wide association methods for studying rapidly evolving traits in bacteria. Genetic association study methods will facilitate the identification of genetic elements likely to cause phenotypes of interest and provide targets for further laboratory investigation.

  12. The Use of Social Ecological Hotspots Mapping: Co-Developing Adaptation Strategies for Resource Management by Communities and Policy Makers

    Science.gov (United States)

    Alessa, L.

    2014-12-01

    Ultimately, adaptation is based on a set of trade-offs rather than optimal conditions, something that is rarely seen in messy social ecological systems (SES). In this talk, we discuss the role of spatial hot-spot mapping using social and biophysical data to understand the feedbacks in SES. We review the types of data needed, their means of acquisition and the analytic methods involved. In addition, we outline the challenges faced in co-developing this type of inquiry based on lessons learned from several long-term programs. Finally, we present the utility of SES hotspots in developing adaptation strategies on the ground by communities and policy makers.

  13. Microbial ecology, bacterial pathogens, and antibiotic resistant genes in swine manure wastewater as influenced by three swine management systems.

    Science.gov (United States)

    Brooks, John P; Adeli, Ardeshir; McLaughlin, Michael R

    2014-06-15

    The environmental influence of farm management in concentrated animal feeding operations (CAFO) can yield vast changes to the microbial biota and ecological structure of both the pig and waste manure lagoon wastewater. While some of these changes may not be negative, it is possible that CAFOs can enrich antibiotic resistant bacteria or pathogens based on farm type, thereby influencing the impact imparted by the land application of its respective wastewater. The purpose of this study was to measure the microbial constituents of swine-sow, -nursery, and -finisher farm manure lagoon wastewater and determine the changes induced by farm management. A total of 37 farms were visited in the Mid-South USA and analyzed for the genes 16S rRNA, spaQ (Salmonella spp.), Camp-16S (Campylobacter spp.), tetA, tetB, ermF, ermA, mecA, and intI using quantitative PCR. Additionally, 16S rRNA sequence libraries were created. Overall, it appeared that finisher farms were significantly different from nursery and sow farms in nearly all genes measured and in 16S rRNA clone libraries. Nearly all antibiotic resistance genes were detected in all farms. Interestingly, the mecA resistance gene (e.g. methicillin resistant Staphylococcus aureus) was below detection limits on most farms, and decreased as the pigs aged. Finisher farms generally had fewer antibiotic resistance genes, which corroborated previous phenotypic data; additionally, finisher farms produced a less diverse 16S rRNA sequence library. Comparisons of Camp-16S and spaQ GU (genomic unit) values to previous culture data demonstrated ratios from 10 to 10,000:1 depending on farm type, indicating viable but not cultivatable bacteria were dominant. The current study indicated that swine farm management schemes positively and negatively affect microbial and antibiotic resistant populations in CAFO wastewater which has future "downstream" implications from both an environmental and public health perspective. Published by Elsevier Ltd.

  14. Preliminary Strategic Environmental Assessment of the Great Western Development Strategy: Safeguarding Ecological Security for a New Western China

    Science.gov (United States)

    Li, Wei; Liu, Yan-Ju; Yang, Zhifeng

    2012-02-01

    The Great Western Development Strategy (GWDS) is a long term national campaign aimed at boosting development of the western area of China and narrowing the economic gap between the western and the eastern parts of China. The Strategic Environmental Assessment (SEA) procedure was employed to assess the environmental challenges brought about by the western development plans. These plans include five key developmental domains (KDDs): water resource exploitation and use, land utilization, energy generation, tourism development, and ecological restoration and conservation. A combination of methods involving matrix assessment, incorporation of expert judgment and trend analysis was employed to analyze and predict the environmental impacts upon eight selected environmental indicators: water resource availability, soil erosion, soil salinization, forest destruction, land desertification, biological diversity, water quality and air quality. Based on the overall results of the assessment, countermeasures for environmental challenges that emerged were raised as key recommendations to ensure ecological security during the implementation of the GWDS. This paper is intended to introduce a consensus-based process for evaluating the complex, long term pressures on the ecological security of large areas, such as western China, that focuses on the use of combined methods applied at the strategic level.

  15. Incorporating resilience and cost in ecological restoration strategies at landscape scale

    Directory of Open Access Journals (Sweden)

    Maurício Stefanes

    2016-12-01

    Full Text Available The restoration of deforested or degraded areas can contribute to biodiversity conservation and global resilience given the current and projected impacts of climate change. In recent years, a robust array of ecological restoration frameworks have been generated to address restoration challenges at large scales in different ecosystems around the world. Unfortunately, the costs associated with restoration at such scales greatly challenges the implementation of such frameworks. We used landscape ecology principles with multicriteria optimization of landscape resilience and agricultural productivity as a way to mitigate the trade-offs between production and restoration. We used the Cerrado biome in Mato Grosso do Sul State, Brazil, as a case study to apply our framework. We compared three scenarios: minimal legal compliance (MLC; selection by ecological resilience (SER; and selection by restoration cost (SRC. Our results show that increasing the restoration target from MLC (25% to SER (30% means moving from 968,316 to 1592 million hectares, which can represent a huge opportunity cost for agricultural lands. However, because costs and resilience are not homogeneously distributed throughout landscapes, we can select areas of intermediate ecological resilience and low cost, for the same restoration area target. This process can reduce potential conflicts and make restoration a more viable process. Our results also reveal some areas that can be particularly important for reconciling agriculture and landscape restoration. Those areas combined high and intermediate resilience and an above average profitability. This could mean that increasing restoration in this area could be very expensive, assuming that our proxy roughly represents the restoration implementation cost. However, there is another important message here, that some areas can be productive at the same time that they maintain levels of resilience above the legal compliance, which facilitates

  16. An empirical strategy to detect bacterial transcript structure from directional RNA-seq transcriptome data.

    Science.gov (United States)

    Wang, Yejun; MacKenzie, Keith D; White, Aaron P

    2015-05-07

    As sequencing costs are being lowered continuously, RNA-seq has gradually been adopted as the first choice for comparative transcriptome studies with bacteria. Unlike microarrays, RNA-seq can directly detect cDNA derived from mRNA transcripts at a single nucleotide resolution. Not only does this allow researchers to determine the absolute expression level of genes, but it also conveys information about transcript structure. Few automatic software tools have yet been established to investigate large-scale RNA-seq data for bacterial transcript structure analysis. In this study, 54 directional RNA-seq libraries from Salmonella serovar Typhimurium (S. Typhimurium) 14028s were examined for potential relationships between read mapping patterns and transcript structure. We developed an empirical method, combined with statistical tests, to automatically detect key transcript features, including transcriptional start sites (TSSs), transcriptional termination sites (TTSs) and operon organization. Using our method, we obtained 2,764 TSSs and 1,467 TTSs for 1331 and 844 different genes, respectively. Identification of TSSs facilitated further discrimination of 215 putative sigma 38 regulons and 863 potential sigma 70 regulons. Combining the TSSs and TTSs with intergenic distance and co-expression information, we comprehensively annotated the operon organization in S. Typhimurium 14028s. Our results show that directional RNA-seq can be used to detect transcriptional borders at an acceptable resolution of ±10-20 nucleotides. Technical limitations of the RNA-seq procedure may prevent single nucleotide resolution. The automatic transcript border detection methods, statistical models and operon organization pipeline that we have described could be widely applied to RNA-seq studies in other bacteria. Furthermore, the TSSs, TTSs, operons, promoters and unstranslated regions that we have defined for S. Typhimurium 14028s may constitute valuable resources that can be used for

  17. Identity Transformation During the Transition to Parenthood Among Same-Sex Couples: An Ecological, Stress-Strategy-Adaptation Perspective

    Science.gov (United States)

    Cao, Hongjian; Mills-Koonce, W. Roger; Wood, Claire; Fine, Mark A.

    2016-01-01

    This article reviews the current research on the potential stressors associated with identity transformation experienced by same-sex couples during the transition to parenthood and the coping strategies they employ. By integrating disparate findings into an ecological, stress-strategy-adaptation framework, we demonstrate that the identity transformation experiences among same-sex couples during the transition to parenthood (a) involve various adaptive processes of navigating different stressors via their human agency within multiple nested contexts; (b) are products of the intersections of individual characteristics, relational dynamics, LGBT community culture, and heterosexual sociostructural norms; and (c) are complicated by social contextual factors such as social class, race/ethnicity, family structure, and the sociocultural environment associated with geographic location. Last, several avenues for future inquiry are suggested. PMID:27458482

  18. Identity Transformation During the Transition to Parenthood Among Same-Sex Couples: An Ecological, Stress-Strategy-Adaptation Perspective.

    Science.gov (United States)

    Cao, Hongjian; Mills-Koonce, W Roger; Wood, Claire; Fine, Mark A

    2016-03-01

    This article reviews the current research on the potential stressors associated with identity transformation experienced by same-sex couples during the transition to parenthood and the coping strategies they employ. By integrating disparate findings into an ecological, stress-strategy-adaptation framework, we demonstrate that the identity transformation experiences among same-sex couples during the transition to parenthood (a) involve various adaptive processes of navigating different stressors via their human agency within multiple nested contexts; (b) are products of the intersections of individual characteristics, relational dynamics, LGBT community culture, and heterosexual sociostructural norms; and (c) are complicated by social contextual factors such as social class, race/ethnicity, family structure, and the sociocultural environment associated with geographic location. Last, several avenues for future inquiry are suggested.

  19. [Simulation of rainfall and snowmelt runoff reduction in a northern city based on combination of green ecological strategies.

    Science.gov (United States)

    Han, Jin Feng; Liu, Shuo; Dai, Jun; Qiu, Hao

    2018-02-01

    With the aim to control and reduce rainfall and snowmelt runoff in northern cities in China, the summer runoff and spring snowmelt runoff in the studied area were simulated with the establishment of storm water management model (SWMM). According to the climate characteristics and the situation of the studied area, the low impact development (LID) green ecological strategies suitable for the studied area were established. There were three kinds of management strategies being used, including extended green roof, snow and rainwater harvesting devices, and grass-swales or trenches. We examined the impacts of those integrated green ecological measures on the summer rainfall and spring snowmelt runoff and their mitigation effects on the drainage network pressure. The results showed that the maximum flow rates of the measured rainfall in May 24th, June 10th and July 18th 2016 were 2.7, 6.2 and 7.4 m 3 ·s -1 respectively. The peak flow rates at different return periods of 1, 2, 5, 10 years were 2.39, 3.91, 6.24 and 7.85 m 3 ·s -1 , respectively. In the snowmelt period, the peak flow appeared at the beginning of March. The LID measures had positive effect on peak flow reduction, and thus delayed peak time and relieved drainage pressure. The flow reduction rate was as high as 70%. Moreover, the snow harvesting devices played a positive role in controlling snowmelt runoff in spring.

  20. Transformation of 'Ukrytie' shelter into an ecologically safe system. Main conditions of strategy, situation and prospects

    International Nuclear Information System (INIS)

    Krivosheev, P.I.; Sokolov, A.P.; Klyuchnikov, A.A.

    1999-01-01

    Present state of nuclear and radiation safety in 'Ukrytie', problems of radiation monitoring, strategy of waste management and conceptual approach in fuel containing mass extraction are analysed. Shelter implementation plan will be used for 'Ukrytie' transformation

  1. A strategy of faster movements used by elderly humans to lift objects of increasing weight in ecological context.

    Science.gov (United States)

    Hoellinger, Thomas; McIntyre, Joseph; Jami, Lena; Hanneton, Sylvain; Cheron, Guy; Roby-Brami, Agnes

    2017-08-15

    It is not known whether, during the course of aging, changes occur in the motor strategies used by the CNS for lifting objects of different weights. Here, we analyzed the kinematics of object-lifting in two different healthy groups (young and elderly people) plus one well-known deafferented patient (GL). The task was to reach and lift onto a shelf an opaque cylindrical object with changing weight. The movements of the hand and object were recorded with electromagnetic sensors. In an ecological context (i.e. no instruction was given about movement speed), we found that younger participants, elderly people and GL did not all move at the same speed and that, surprisingly, elder people are faster. We also observed that the lifting trajectories were constant for both the elderly and the deafferented patient while younger participants raised their hand higher when the object weighed more. It appears that, depending on age and on available proprioceptive information, the CNS uses different strategies of lifting. We suggest that elder people tend to optimize their feedforward control in order to compensate for less functional afferent feedback, perhaps to optimize movement time and energy expenditure at the expense of high precision. In the case of complete loss of proprioceptive input, however, compensation follows a different strategy as suggested by GL's behavior who moved more slowly compared to both our younger and older participants. Copyright © 2017. Published by Elsevier Ltd.

  2. A global method for calculating plant CSR ecological strategies applied across biomes world-wide

    NARCIS (Netherlands)

    Pierce, S.; Negreiros, D.; Cerabolini, B.E.L.; Kattge, J.; Díaz, S.; Kleyer, M.; Shipley, B.; Wright, S.J.; Soudzilovskaia, N.A.; Onipchenko, V.G.; van Bodegom, P.M.; Frenette-Dussault, C.; Weiher, E.; Pinho, B.X.; Cornelissen, J.H.C.; Grime, J.P.; Thompson, K.; Hunt, R.; Wilson, P.J.; Buffa, G.; Nyakunga, O.C.; Reich, P.B.; Caccianiga, M.; Mangili, F.; Ceriani, R.M.; Luzzaro, A.; Brusa, G.; Siefert, A.; Barbosa, N.P.U.; Chapin III, F.S.; Cornwell, W.K.; Fang, Jingyun; Wilson Fernandez, G.; Garnier, E.; Le Stradic, S.; Peñuelas, J.; Melo, F.P.L.; Slaviero, A.; Tabarrelli, M.; Tampucci, D.

    2017-01-01

    Competitor, stress-tolerator, ruderal (CSR) theory is a prominent plant functional strategy scheme previously applied to local floras. Globally, the wide geographic and phylogenetic coverage of available values of leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA)

  3. Human Populations and the World Conservation Strategy. Commission on Ecology Paper Number 11.

    Science.gov (United States)

    Hanks, J.

    This document serves as a supplement to the World Conservation Strategy (WCS) and outlines some of the critical aspects of the interaction between human populations, natural resources, and social and economic conditions. Particular emphasis is placed on the importance of planning with people, and on packaging conservation programs so they are more…

  4. Responses to climate and economic risks and opportunities across national and ecological boundaries: changing household strategies on the Mongolian plateau

    International Nuclear Information System (INIS)

    Brown, Daniel G; Agrawal, Arun; Wang, Jun; Sass, Daniel A; Hua, Jin; Xie, Yichun

    2013-01-01

    Climate changes on the Mongolian Plateau are creating new challenges for the households and communities of the region. Much of the existing research on household choices in response to climate variability and change focuses on environmental risks and stresses. In contrast, our analysis highlights the importance of taking into account environmental and economic opportunities in explaining household adaptation choices. We surveyed over 750 households arrayed along an ecological gradient and matched across the national border in Mongolia and the Inner Mongolia Autonomous Region, China, asking what changes in livelihoods strategies households made over the last ten years, and analyzed these choices in two broad categories of options: diversification and livestock management. We combined these data with remotely sensed information about vegetation growth and self-reported exposure to price fluctuations. Our statistical results showed that households experiencing lower ecological and economic variability, higher average levels of vegetation growth, and with greater levels of material wealth, were often those that undertook more actions to improve their conditions in the face of variability. The findings have implications both for how interventions aimed at supporting ongoing choices might be targeted and for theory construction related to social adaptation. (letter)

  5. Approach and strategy for performing ecological risk assessments for the US Department of Energy's Oak Ridge Reservation: 1995 revision

    International Nuclear Information System (INIS)

    Suter, G.W. II; Sample, B.E.; Jones, D.S.; Ashwood, T.L.; Loar, J.M.

    1995-09-01

    The purpose of this document is to provide guidance for planning and performing ecological risk assessments (ERAs) on the Oak Ridge Reservation (ORR). It is the third such document prepared for this purpose. The first ecorisk strategy document described the ERA process and presented a tiered approach to ERAs appropriate to complex sites. The first revision was necessitated by the considerable progress that has been made by the parties to the Federal Facilities Agreement (FFA) for the ORR in resolving specific issues relating to ERA as a result of a series of data quality objectives (DQOs) meetings. The tiered approach to ERAs as recommended in the first document was implemented, generic conceptual models were developed, and a general approach for developing ecological assessment endpoints and measurement endpoints was agreed upon. This revision is necessitated by comments from the US Environmental Protection Agency's Region IV and the Tennessee Department of Environment and Conservation (TDEC) which clarified and modified the positions taken during the DQO process. In particular, support for the collection of data that would support ERAs for all OUs on the ORR have been withdrawn. Therefore, the work plan developed to fill the reservation-wide data needs identified in the DQO process has also been withdrawn, and portions that are still relevant have been incorporated into this document. The reader should be aware that this guidance is complex and lengthy because it attempts to cover all the reasonable contingencies that were considered to be potentially important to the FFA parties

  6. The role of grazer predation strategies in the dynamics of consumer-resource based ecological models

    Science.gov (United States)

    Cropp, Roger; Moroz, Irene; Norbury, John

    2017-07-01

    We analyse a simple plankton system to provide a heuristic for more complex models such as Dynamic Green Ocean Models (DGOMs). Zooplankton foraging is either by generalist grazers that consume whatever they bump into or specialist grazers that actively seek particular prey. The zooplankton may further be classified as either facultative grazers that can survive on any of their prey or obligate grazers that depend on the presence of specific prey. A key result is that different prey dependencies can result in dramatically different impacts of grazing strategies on system outcomes. The grazing strategy can determine whether a system with obligate grazers will be stable, have regular, predictable cycles or be chaotic. Conversely, whether facultative zooplankton functioned as specialist or generalist grazers makes no qualitative difference to the dynamics of the system. These results demonstrate that the effect of different grazing strategies can be critically dependent on the grazer's dependency on specific prey. Great care must be taken when choosing functional forms for population interactions in DGOMs, particularly in scenarios such as climate change where parameters such as mortality and growth coefficients may change. A robust theoretical framework supporting model development and analysis is key to understanding how such choices can affect model properties and hence predictions.

  7. Molecular sexing of threatened Gyps vultures: an important strategy for conservation breeding and ecological studies.

    Science.gov (United States)

    Ghorpade, Prabhakar B; Gupta, Praveen K; Prakash, Vibhu; Cuthbert, Richard J; Kulkarni, Mandar; Prakash, Nikita; Das, Asit; Sharma, Anil K; Saini, Mohini

    2012-12-01

    During the last two decades populations of three resident species of Gyps vulture have declined dramatically and are now threatened with extinction in South Asia. Sex identification of vultures is of key importance for the purpose of conservation breeding as it is desirable to have an equal sex ratio in these monogamous species which are housed together in large colony aviaries. Because vultures are monomorphic, with no differences in external morphology or plumage colour between the sexes, other methods are required for sex identification. Molecular methods for sex identification in birds rely on allelic length or nucleotide sequence discrimination of the chromohelicase-DNA binding (CHD) gene located on male and female chromosomes ZZ and ZW, respectively. We characterized the partial sequences of CHD alleles from Gyps indicus, Gyps bengalensis, Gyps himalayensis and Aegypius monachus and analysed the applicability of five molecular methods of sex identification of 46 individual vultures including 26 known-sex G. bengalensis and G. indicus. The results revealed that W-specific PCR in combination with ZW-common PCR is a quick, accurate and simple method, and is ideal for sex identification of vultures. The method is also suitable to augment ecological studies for identifying sex of these endangered birds during necropsy examinations especially when gonads are not apparent, possibly due to regression during non-breeding seasons.

  8. Ecological strategies in california chaparral: Interacting effects of soils, climate, and fire on specific leaf area

    Science.gov (United States)

    Anacker, Brian; Rajakaruna, Nishanta; Ackerly, David; Harrison, Susan; Keeley, Jon E.; Vasey, Michael

    2011-01-01

    Background: High values of specific leaf area (SLA) are generally associated with high maximal growth rates in resource-rich conditions, such as mesic climates and fertile soils. However, fire may complicate this relationship since its frequency varies with both climate and soil fertility, and fire frequency selects for regeneration strategies (resprouting versus seeding) that are not independent of resource-acquisition strategies. Shared ancestry is also expected to affect the distribution of resource-use and regeneration traits.Aims: We examined climate, soil, and fire as drivers of community-level variation in a key functional trait, SLA, in chaparral in California.Methods: We quantified the phylogenetic, functional, and environmental non-independence of key traits for 87 species in 115 plots.Results: Among species, SLA was higher in resprouters than seeders, although not after phylogeny correction. Among communities, mean SLA was lower in harsh interior climates, but in these climates it was higher on more fertile soils and on more recently burned sites; in mesic coastal climates, mean SLA was uniformly high despite variation in soil fertility and fire history.Conclusions: We conclude that because important correlations exist among both species traits and environmental filters, interpreting the functional and phylogenetic structure of communities may require an understanding of complex interactive effects.

  9. Assessment of agro-ecological service crop managements combined with organic fertilisation strategies in organic melon crop

    Directory of Open Access Journals (Sweden)

    Mariangela Diacono

    2018-05-01

    Full Text Available In organic horticultural systems, cover crops could provide several ecological services, therefore, they can be defined agroecological service crops (ASCs. The objective of this two-year research was to study the suitability on melon production of different ASC termination strategies, in combination with organic fertilisers application. In a split-block design, the main-plot was the ASC management, comparing: i green manure, in which the vetch was chopped and plowed into the soil; and ii roller-crimper (RC, in which the vetch was flattened by a roller-crimper; with iii fallow control, without vetch. The subplot consisted of offfarm organic inputs: i commercial humified fertiliser; ii anaerobic digestate fertiliser; iii composted municipal solid wastes; which were compared to iv unfertilised control (N0. At vetch termination, above soil biomass and nitrogen (N content were determined. At harvesting, crop yield performance and quality, N status and N efficiency were investigated. Also, main soil characteristics were assessed at the end of the trial. Among the ASC managements, the slightly reduced yield in the RC plots particularly in combination with N0 might have been the result of less N supplied by the vetch during the melon cycle. Anyway, no negative effects were observed for yield quality. The use of the RC showed a great potential in enhancing soil fertility. Our study suggests the suitability in organic farming of properly matching management of ASC and fertilisation strategies on melon crop.

  10. Effect of cardiovascular prevention strategies on incident coronary disease hospitalisation rates in Spain; an ecological time series analysis.

    Science.gov (United States)

    Medrano, María José; Alcalde-Cabero, Enrique; Ortíz, Cristina; Galán, Iñaki

    2014-02-17

    To assess the overall population impact of primary prevention strategies (promotion of healthy lifestyles, prevention of smoking and use of vascular risk drug therapy) of coronary disease in Spain. Ecological time series analysis, 1982-2009. All public and private hospitals in Spain. General population. Incident coronary disease hospitalisation as derived from official hospital discharge data. Annual hospitalisation rates were modelled according to nationwide use of statins, antihypertensive, antidiabetic and antiplatelet drugs, and prevalences of smoking, obesity and overweight. Additive generalised models and mixed Poisson regression models were used for the purpose, taking year as the random-effect variable and adjusting for age, sex, prevalence of vascular risk factors and the number of hospital beds in intensive and coronary care units. Across 28 years and 671.5 million person-years of observation, there were 2 986 834 hospitalisations due to coronary disease; of these, 1 441 980 (48.28%) were classified as incident. Hospitalisation rates increased from 1982 to 1996, with an inflection point in 1997 and a subsequent 52% decrease until 2009. Prevalences of smoking, obesity, overweight and use of vascular risk drug therapy were significantly associated with hospitalisation rates (pcrisis. Future strategies ought to lay special stress on excessive body weight prevention.

  11. Ecological strategies of Al-accumulating and non-accumulating functional groups from the cerrado sensu stricto

    Directory of Open Access Journals (Sweden)

    Marcelo C. de Souza

    2015-06-01

    Full Text Available The cerrado's flora comprises aluminum-(Al accumulating and non-accumulating plants, which coexist on acidic and Al-rich soils with low fertility. Despite their existence, the ecological importance or biological strategies of these functional groups have been little explored. We evaluated the leaf flushing patterns of both groups throughout a year; leaf concentrations of N, P, K, Ca, Mg, S, Al, total flavonoids and polyphenols; as well as the specific leaf area (SLA on young and mature leaves within and between the groups. In Al-accumulating plants, leaf flushed throughout the year, mainly in May and September; for non-accumulating plants, leaf flushing peaked at the dry-wet seasons transition. However, these behaviors could not be associated with strategies for building up concentrations of defense compounds in leaves of any functional groups. Al-accumulating plants showed low leaf nutrient concentrations, while non-accumulating plants accumulated more macronutrients and produced leaves with high SLA since the juvenile leaf phase. This demonstrates that the increase in SLA is slower in Al-accumulating plants that are likely to achieve SLA values comparable to the rest of the plant community only in the wet season, when sunlight capture is important for the growth of new branches.

  12. Ecological strategies of Al-accumulating and non-accumulating functional groups from the cerrado sensu stricto.

    Science.gov (United States)

    Souza, Marcelo C de; Bueno, Paula C P; Morellato, Leonor P C; Habermann, Gustavo

    2015-01-01

    The cerrado's flora comprises aluminum-(Al) accumulating and non-accumulating plants, which coexist on acidic and Al-rich soils with low fertility. Despite their existence, the ecological importance or biological strategies of these functional groups have been little explored. We evaluated the leaf flushing patterns of both groups throughout a year; leaf concentrations of N, P, K, Ca, Mg, S, Al, total flavonoids and polyphenols; as well as the specific leaf area (SLA) on young and mature leaves within and between the groups. In Al-accumulating plants, leaf flushed throughout the year, mainly in May and September; for non-accumulating plants, leaf flushing peaked at the dry-wet seasons transition. However, these behaviors could not be associated with strategies for building up concentrations of defense compounds in leaves of any functional groups. Al-accumulating plants showed low leaf nutrient concentrations, while non-accumulating plants accumulated more macronutrients and produced leaves with high SLA since the juvenile leaf phase. This demonstrates that the increase in SLA is slower in Al-accumulating plants that are likely to achieve SLA values comparable to the rest of the plant community only in the wet season, when sunlight capture is important for the growth of new branches.

  13. Techniques and management strategies for environmental restoration and their ecological consequences

    International Nuclear Information System (INIS)

    Gutierrez, J.; Vazquez, C.; Meckbach, R.; Wilkins, B.; Rafferty, B.; Holm, E.; Badie, M.; Burton, O.

    2000-01-01

    The intervention is one of the targeted situations of concern for radiological protection. One of the aspects of the intervention deals with the environmental restoration. In fact, the emergency measures taken immediately or shortly after an accident, in order to avoid unnecessary increases of radiological risks, shoul not be prolonged for long periods because of their elevated cost for society. Hence restoration of the contaminated areas could be needed and therefore researches are required for theevelopmet of obust d optimised restoration strategies. The experimental work carried out after the Chernobyl accident provided large amount of information about the environmental behaviour of radionuclides and their exposure pathways to man. Additionally, some advance on the setting up of intervention methodologies was produced, concluding that the postaccident environmental restoration is possible and desirable. However, for restoration purpose, some limitations remained concerning the capacity to predict the transfer and fluxes of radionuclides (strongly dependent on the local specificity and no directly exchangeable from one place to another) and the correct assessment of the performance of the applicable countermeasures. In the first case, a possible approach to solve the problem would be the identification and further use of some local characteristics (of the scenario of contamination), to predict, using adequate radioecological models, the behaviour of the radionuclides (and their radiological consequences) for places and times different than those experimental sites where information exists. Concerning the second problem, one must identify the features of the scenario having influence on the performance of the countermeasures and to consider those factors (not only radiological) related to their applicability, cost and secondary effects, including the management and disporadiological impact and the countermeasures performance , are unavoidable to face the

  14. Using ecological forecasting of future vegetation transition and fire frequency change in the Sierra Nevada to assess fire management strategies

    Science.gov (United States)

    Thorne, J. H.; Schwartz, M. W.; Holguin, A. J.; Moritz, M.; Batllori, E.; Folger, K.; Nydick, K.

    2013-12-01

    Ecological systems may respond in complex manners as climate change progresses. Among the responses, site-level climate conditions may cause a shift in vegetation due to the physiological tolerances of plant species, and the fire return interval may change. Natural resource managers challenged with maintaining ecosystem health need a way to forecast how these processes may affect every location, in order to determine appropriate management actions and prioritize locations for interventions. We integrated climate change-driven vegetation type transitions with projected change in fire frequency for 45,203 km2 of the southern Sierra Nevada, California, containing over 10 land management agencies as well as private lands. This Magnitude of Change (MOC) approach involves classing vegetation types in current time according to their climate envelopes, and identifying which sites will in the future have climates beyond what that vegetation currently occurs in. Independently, fire models are used to determine the change in fire frequency for each site. We examined 82 vegetation types with >50 grid cell occurrences. We found iconic resources such as the giant sequoia, lower slope oak woodlands, and high elevation conifer forests are projected as highly vulnerable by models that project a warmer drier future, but not as much by models that project a warmer future that is not drier than current conditions. Further, there were strongly divergent vulnerabilities of these forest types across land ownership (National Parks versus US Forest Service lands), and by GCM. For example, of 50 giant sequoia (Sequoiadendron giganteum) groves and complexes, all but 3 (on Sierra National Forest) were in the 2 highest levels of risk of climate and fire under the GFDL A2 projection, while 15 groves with low-to-moderate risk were found on both the National Parks and National Forests 18 in the 2 under PCM A2. Landscape projections of potential MOC suggest that the region is likely to experience

  15. Quorum signaling mycotoxins: A new risk strategy for bacterial biocontrol of Fusarium verticillioides and other endophytic fungal species?

    Science.gov (United States)

    Bacterial endophytes are used as biocontrol organisms for plant pathogens such as the maize endophyte Fusarium verticillioides and its production of fumonisin mycotoxins. However, such applications are not always predictable and efficient. All bacteria communicate via cell-dependent signals, which...

  16. Microbial population analysis of the salivary glands of ticks; a possible strategy for the surveillance of bacterial pathogens.

    Directory of Open Access Journals (Sweden)

    Yongjin Qiu

    Full Text Available Ticks are one of the most important blood-sucking vectors for infectious microorganisms in humans and animals. When feeding they inject saliva, containing microbes, into the host to facilitate the uptake of blood. An understanding of the microbial populations within their salivary glands would provide a valuable insight when evaluating the vectorial capacity of ticks. Three tick species (Ixodes ovatus, I. persulcatus and Haemaphysalis flava were collected in Shizuoka Prefecture of Japan between 2008 and 2011. Each tick was dissected and the salivary glands removed. Bacterial communities in each salivary gland were characterized by 16S amplicon pyrosequencing using a 454 GS-Junior Next Generation Sequencer. The Ribosomal Database Project (RDP Classifier was used to classify sequence reads at the genus level. The composition of the microbial populations of each tick species were assessed by principal component analysis (PCA using the Metagenomics RAST (MG-RAST metagenomic analysis tool. Rickettsia-specific PCR was used for the characterization of rickettsial species. Almost full length of 16S rDNA was amplified in order to characterize unclassified bacterial sequences obtained in I. persulcatus female samples. The numbers of bacterial genera identified for the tick species were 71 (I. ovatus, 127 (I. persulcatus and 59 (H. flava. Eighteen bacterial genera were commonly detected in all tick species. The predominant bacterial genus observed in all tick species was Coxiella. Spiroplasma was detected in Ixodes, and not in H. flava. PCA revealed that microbial populations in tick salivary glands were different between tick species, indicating that host specificities may play an important role in determining the microbial complement. Four female I. persulcatus samples contained a high abundance of several sequences belonging to Alphaproteobacteria symbionts. This study revealed the microbial populations within the salivary glands of three species of

  17. An Integrated Optimal Energy Management/Gear-Shifting Strategy for an Electric Continuously Variable Transmission Hybrid Powertrain Using Bacterial Foraging Algorithm

    Directory of Open Access Journals (Sweden)

    Syuan-Yi Chen

    2016-01-01

    Full Text Available This study developed an integrated energy management/gear-shifting strategy by using a bacterial foraging algorithm (BFA in an engine/motor hybrid powertrain with electric continuously variable transmission. A control-oriented vehicle model was constructed on the Matlab/Simulink platform for further integration with developed control strategies. A baseline control strategy with four modes was developed for comparison with the proposed BFA. The BFA was used with five bacterial populations to search for the optimal gear ratio and power-split ratio for minimizing the cost: the equivalent fuel consumption. Three main procedures were followed: chemotaxis, reproduction, and elimination-dispersal. After the vehicle model was integrated with the vehicle control unit with the BFA, two driving patterns, the New European Driving Cycle and the Federal Test Procedure, were used to evaluate the energy consumption improvement and equivalent fuel consumption compared with the baseline. The results show that [18.35%,21.77%] and [8.76%,13.81%] were improved for the optimal energy management and integrated optimization at the first and second driving cycles, respectively. Real-time platform designs and vehicle integration for a dynamometer test will be investigated in the future.

  18. Implementation of the Integrated Management of Childhood Illness strategy in Peru and its association with health indicators: an ecological analysis.

    Science.gov (United States)

    Huicho, Luis; Dávila, Miguel; Gonzales, Fernando; Drasbek, Christopher; Bryce, Jennifer; Victora, Cesar G

    2005-12-01

    The Multi-Country Evaluation of Integrated Management of Childhood Illness (IMCI) Effectiveness, Cost and Impact (MCE) was launched to assess the global effectiveness of this strategy. Impact evaluations were started in five countries. The objectives of the Peru MCE were: (1) to document trends in IMCI implementation in the 24 departments of Peru from 1996 to 2000; (2) to document trends in indicators of health services coverage and impact (mortality and nutritional status) for the same period; (3) to correlate changes in these two sets of indicators, and (4) to attempt to rule out contextual factors that may affect the observed trends and correlations. An ecological analysis was performed in which the units of study were the 24 departments. By 2000, 10.2% of clinical health workers were trained in IMCI, but some districts showed considerably higher rates. There were no significant associations between clinical IMCI training coverage and indicators of outpatient utilization, vaccine coverage, mortality or malnutrition. The lack of association persisted after adjustment for several contextual factors including socioeconomic and environmental indicators and the presence of other child health projects. Community health workers were also trained in IMCI, and training coverage was not associated with any of the process or impact indicators, except for a significant positive correlation with mean height for age. According to the MCE impact model, IMCI implementation must be sufficiently strong to lead to an impact on health and nutrition. Health systems support for IMCI implementation in Peru was far from adequate. This finding, along with low training coverage level and a relatively low child mortality rate, may explain why the expected impact was not documented. Nevertheless, even districts with high levels of training coverage failed to show an impact. Further national effectiveness studies of IMCI and other child interventions are warranted as these interventions are

  19. Bacterial Transport in Heterogeneous Porous Media: Laboratory and Field Experiments

    Science.gov (United States)

    Fuller, M. E.

    2001-12-01

    A fully instrumented research site for examining field-scale bacterial transport has been established on the eastern shore of Virginia. Studies employing intact sediment cores from the South Oyster site have been performed to examine the effects of physical and chemical heterogeneity, to derive transport parameters, and to aid in the selection of bacterial strains for use in field experiments. A variety of innovative methods for tracking bacteria were developed and evaluated under both laboratory and field conditions, providing the tools to detect target cell concentrations in groundwater down to effects of physical and chemical heterogeneity on field-scale bacterial transport. The results of this research not only contribute to the development of more effective bioremediation strategies, but also have implications for a better understanding of bacterial movement in the subsurface as it relates to public health microbiology and general microbial ecology.

  20. Extensive phylogenetic analysis of a soil bacterial community illustrates extreme taxon evenness and the effects of amplicon length, degree of coverage, and DNA fractionation on classification and ecological parameters.

    Science.gov (United States)

    Morales, Sergio E; Cosart, Theodore F; Johnson, Jesse V; Holben, William E

    2009-02-01

    To thoroughly investigate the bacterial community diversity present in a single composite sample from an agricultural soil and to examine potential biases resulting from data acquisition and analytical approaches, we examined the effects of percent G+C DNA fractionation, sequence length, and degree of coverage of bacterial diversity on several commonly used ecological parameters (species estimation, diversity indices, and evenness). We also examined variation in phylogenetic placement based on multiple commonly used approaches (ARB alignments and multiple RDP tools). The results demonstrate that this soil bacterial community is highly diverse, with 1,714 operational taxonomic units demonstrated and 3,555 estimated (based on the Chao1 richness estimation) at 97% sequence similarity using the 16S rRNA gene. The results also demonstrate a fundamental lack of dominance (i.e., a high degree of evenness), with 82% of phylotypes being encountered three times or less. The data also indicate that generally accepted cutoff values for phylum-level taxonomic classification might not be as applicable or as general as previously assumed and that such values likely vary between prokaryotic phyla or groups.

  1. Developing sporophytes transition from an inducible to a constitutive ecological strategy of desiccation tolerance in the moss Aloina ambigua: effects of desiccation on fitness.

    Science.gov (United States)

    Stark, Lloyd R; Brinda, John C

    2015-03-01

    Two ecological strategies of desiccation tolerance exist in plants, constitutive and inducible. Because of difficulties in culturing sporophytes, very little is known about desiccation tolerance in this generation and how desiccation affects sexual fitness. Cultured sporophytes and vegetative shoots from a single genotype of the moss Aloina ambigua raised in the laboratory were tested for their strategy of desiccation tolerance by desiccating the shoot-sporophyte complex and vegetative shoots at different intensities, and comparing outcomes with those of undried shoot-sporophyte complexes and vegetative shoots. By using a dehardened clonal line, the effects of field, age and genetic variance among plants were removed. The gametophyte and embryonic sporophyte were found to employ a predominantly inducible strategy of desiccation tolerance, while the post-embryonic sporophyte was found to employ a moderately constitutive strategy of desiccation tolerance. Further, desiccation reduced sporophyte fitness, as measured by sporophyte mass, seta length and capsule size. However, the effects of desiccation on sporophyte fitness were reduced if the stress occurred during embryonic development as opposed to postembryonic desiccation. The effects of desiccation on dehardened sporophytes of a bryophyte are shown for the first time. The transition from one desiccation tolerance strategy to the other in a single structure or generation is shown for only the second time in plants and for the first time in bryophytes. Finding degrees of inducible strategies of desiccation tolerance in different life phases prompts the formulation of a continuum hypothesis of ecological desiccation tolerance in mosses, where desiccation tolerance is not an either/or phenomenon, but varies in degree along a gradient of ecological inducibility. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email

  2. Microbial ecology of the hive and pollination landscape: bacterial associates from floral nectar, the alimentary tract and stored food of honey bees (Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Kirk E Anderson

    Full Text Available Nearly all eukaryotes are host to beneficial or benign bacteria in their gut lumen, either vertically inherited, or acquired from the environment. While bacteria core to the honey bee gut are becoming evident, the influence of the hive and pollination environment on honey bee microbial health is largely unexplored. Here we compare bacteria from floral nectar in the immediate pollination environment, different segments of the honey bee (Apis mellifera alimentary tract, and food stored in the hive (honey and packed pollen or "beebread". We used cultivation and sequencing to explore bacterial communities in all sample types, coupled with culture-independent analysis of beebread. We compare our results from the alimentary tract with both culture-dependent and culture-independent analyses from previous studies. Culturing the foregut (crop, midgut and hindgut with standard media produced many identical or highly similar 16S rDNA sequences found with 16S rDNA clone libraries and next generation sequencing of 16S rDNA amplicons. Despite extensive culturing with identical media, our results do not support the core crop bacterial community hypothesized by recent studies. We cultured a wide variety of bacterial strains from 6 of 7 phylogenetic groups considered core to the honey bee hindgut. Our results reveal that many bacteria prevalent in beebread and the crop are also found in floral nectar, suggesting frequent horizontal transmission. From beebread we uncovered a variety of bacterial phylotypes, including many possible pathogens and food spoilage organisms, and potentially beneficial bacteria including Lactobacillus kunkeei, Acetobacteraceae and many different groups of Actinobacteria. Contributions of these bacteria to colony health may include general hygiene, fungal and pathogen inhibition and beebread preservation. Our results are important for understanding the contribution to pollinator health of both environmentally vectored and core microbiota

  3. Microbial ecology of the hive and pollination landscape: bacterial associates from floral nectar, the alimentary tract and stored food of honey bees (Apis mellifera).

    Science.gov (United States)

    Anderson, Kirk E; Sheehan, Timothy H; Mott, Brendon M; Maes, Patrick; Snyder, Lucy; Schwan, Melissa R; Walton, Alexander; Jones, Beryl M; Corby-Harris, Vanessa

    2013-01-01

    Nearly all eukaryotes are host to beneficial or benign bacteria in their gut lumen, either vertically inherited, or acquired from the environment. While bacteria core to the honey bee gut are becoming evident, the influence of the hive and pollination environment on honey bee microbial health is largely unexplored. Here we compare bacteria from floral nectar in the immediate pollination environment, different segments of the honey bee (Apis mellifera) alimentary tract, and food stored in the hive (honey and packed pollen or "beebread"). We used cultivation and sequencing to explore bacterial communities in all sample types, coupled with culture-independent analysis of beebread. We compare our results from the alimentary tract with both culture-dependent and culture-independent analyses from previous studies. Culturing the foregut (crop), midgut and hindgut with standard media produced many identical or highly similar 16S rDNA sequences found with 16S rDNA clone libraries and next generation sequencing of 16S rDNA amplicons. Despite extensive culturing with identical media, our results do not support the core crop bacterial community hypothesized by recent studies. We cultured a wide variety of bacterial strains from 6 of 7 phylogenetic groups considered core to the honey bee hindgut. Our results reveal that many bacteria prevalent in beebread and the crop are also found in floral nectar, suggesting frequent horizontal transmission. From beebread we uncovered a variety of bacterial phylotypes, including many possible pathogens and food spoilage organisms, and potentially beneficial bacteria including Lactobacillus kunkeei, Acetobacteraceae and many different groups of Actinobacteria. Contributions of these bacteria to colony health may include general hygiene, fungal and pathogen inhibition and beebread preservation. Our results are important for understanding the contribution to pollinator health of both environmentally vectored and core microbiota, and the

  4. The Bacteriome of Bat Flies (Nycteribiidae) from the Malagasy Region: a Community Shaped by Host Ecology, Bacterial Transmission Mode, and Host-Vector Specificity.

    Science.gov (United States)

    Wilkinson, David A; Duron, Olivier; Cordonin, Colette; Gomard, Yann; Ramasindrazana, Beza; Mavingui, Patrick; Goodman, Steven M; Tortosa, Pablo

    2016-01-08

    The Nycteribiidae are obligate blood-sucking Diptera (Hippoboscoidea) flies that parasitize bats. Depending on species, these wingless flies exhibit either high specialism or generalism toward their hosts, which may in turn have important consequences in terms of their associated microbial community structure. Bats have been hypothesized to be reservoirs of numerous infectious agents, some of which have recently emerged in human populations. Thus, bat flies may be important in the epidemiology and transmission of some of these bat-borne infectious diseases, acting either directly as arthropod vectors or indirectly by shaping pathogen communities among bat populations. In addition, bat flies commonly have associations with heritable bacterial endosymbionts that inhabit insect cells and depend on maternal transmission through egg cytoplasm to ensure their transmission. Some of these heritable bacteria are likely obligate mutualists required to support bat fly development, but others are facultative symbionts with unknown effects. Here, we present bacterial community profiles that were obtained from seven bat fly species, representing five genera, parasitizing bats from the Malagasy region. The observed bacterial diversity includes Rickettsia, Wolbachia, and several Arsenophonus-like organisms, as well as other members of the Enterobacteriales and a widespread association of Bartonella bacteria from bat flies of all five genera. Using the well-described host specificity of these flies and data on community structure from selected bacterial taxa with either vertical or horizontal transmission, we show that host/vector specificity and transmission mode are important drivers of bacterial community structure. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  5. A Trojan-Horse Strategy Including a Bacterial Suicide Action for the Efficient Use of a Specific Gram-Positive Antibiotic on Gram-Negative Bacteria.

    Science.gov (United States)

    Schalk, Isabelle J

    2018-05-10

    In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. The need for new antibiotics is even more urgent in the case of Gram-negative bacteria, such as Acinetobacter, Pseudomonas, and Enterobacteria, which have become resistant to many antibiotics and have an outer membrane with very low permeability to drugs. Vectorization of antibiotics using siderophores may be a solution to bypass such a bacterial wall: the drugs use the iron transporters of the outer membrane as gates to enter bacteria in a Trojan-horse strategy. Designing siderophore-antibiotics that can cross outer membranes has become almost routine, but their transport across the inner membrane is still a limiting step, as well as a strategy that allows dissociation of the antibiotic from the siderophore once inside the bacteria. Liu et al. ( J. Med. Chem. 2018 , DOI: 10.1021/acs.jmedchem.8b00218 ) report the synthesis of a siderophore-cephalosporin compound and demonstrate that β-lactams, such as cephalosporins, can serve as β-lactamase-triggered releasable linkers to allow intracellular delivery of Gram-positive antibiotics to Gram-negative bacteria.

  6. Natural vegetal regeneration as a basis for the development of strategies for ecological restoration in three Protected Biotopes in the Maya Biosphere Reserve, Guatemala

    Directory of Open Access Journals (Sweden)

    Manolo José García Vettorazzi

    2015-07-01

    Full Text Available The natural ecosystems of the Maya Biosphere Reserve contain high levels of biodiversity providing environmental goods and services to society, so their conservation is strategic for local and regional development. However, there is a increasing tendency to disturb these ecosystems as a result of human activities, so is necessary to develop strategies that minimize the negative impacts and allow the recovery of degraded natural ecosystems. Existing information on the functioning of essential ecological processes of local ecosystems is sparse and is scattered, limiting the development of strategies. It was proposed to study the dynamics of natural regeneration of vegetation as a basis for defining strategies of ecological restoration in three Protected Biotopes in Peten and adjacent areas, by characterizing the structure and composition of vegetation in six categories of natural regeneration and forest without recent disturbance. Two modified Whitaker 0.1 ha plots were plotted by category and seed bank samples were collected. With this information a conceptual framework of natural regeneration was developed for application in restoration strategies at local and landscape scales.

  7. Ecology of root colonizing Massilia (Oxalobacteraceae.

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    Maya Ofek

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

  8. Ecology of root colonizing Massilia (Oxalobacteraceae).

    Science.gov (United States)

    Ofek, Maya; Hadar, Yitzhak; Minz, Dror

    2012-01-01

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

  9. Classic, fuzzy and predictive dtc strategies for the PMSM using the bacterial foraging algorithmas an online parameter estimator

    Directory of Open Access Journals (Sweden)

    Gabriel Noriega

    2012-01-01

    Full Text Available Este trabajo presenta una comparación entre cuatro técnicas de control directo de par (DTC aplicadas al accionamiento de la máquina sincrónica deimán permanente: Clásico, Modificado con un sistema de inferencia difusa, Predictivo y Predictivo con inferencia difusa. La estimación de parámetros para las estrategias predictivas es realizado utilizando un algoritmo de búsqueda poblacional basado en Forraje Bacterial, el cuál es capaz de calcular en línea los parámetros de la máquina sincrónica de imán permanente. Los resultados experimentales del par eléctrico y de los enlaces de flujo del estator muestran mejoras significativas para las estrategias predictivas que utilizan algoritmos de estimación paramétrica mediante Forraje Bacterial cuando se comparan con técnicas no predictivas.

  10. The in planta transcriptome of Ralstonia solanacearum: conserved physiological and virulence strategies during bacterial wilt of tomato.

    Science.gov (United States)

    Jacobs, Jonathan M; Babujee, Lavanya; Meng, Fanhong; Milling, Annett; Allen, Caitilyn

    2012-01-01

    Plant xylem fluid is considered a nutrient-poor environment, but the bacterial wilt pathogen Ralstonia solanacearum is well adapted to it, growing to 10(8) to 10(9) CFU/g tomato stem. To better understand how R. solanacearum succeeds in this habitat, we analyzed the transcriptomes of two phylogenetically distinct R. solanacearum strains that both wilt tomato, strains UW551 (phylotype II) and GMI1000 (phylotype I). We profiled bacterial gene expression at ~6 × 10(8) CFU/ml in culture or in plant xylem during early tomato bacterial wilt pathogenesis. Despite phylogenetic differences, these two strains expressed their 3,477 common orthologous genes in generally similar patterns, with about 12% of their transcriptomes significantly altered in planta versus in rich medium. Several primary metabolic pathways were highly expressed during pathogenesis. These pathways included sucrose uptake and catabolism, and components of these pathways were encoded by genes in the scrABY cluster. A UW551 scrA mutant was significantly reduced in virulence on resistant and susceptible tomato as well as on potato and the epidemiologically important weed host Solanum dulcamara. Functional scrA contributed to pathogen competitive fitness during colonization of tomato xylem, which contained ~300 µM sucrose. scrA expression was induced by sucrose, but to a much greater degree by growth in planta. Unexpectedly, 45% of the genes directly regulated by HrpB, the transcriptional activator of the type 3 secretion system (T3SS), were upregulated in planta at high cell densities. This result modifies a regulatory model based on bacterial behavior in culture, where this key virulence factor is repressed at high cell densities. The active transcription of these genes in wilting plants suggests that T3SS has a biological role throughout the disease cycle. IMPORTANCE Ralstonia solanacearum is a widespread plant pathogen that causes bacterial wilt disease. It inflicts serious crop losses on tropical

  11. The Gut Microbiota of Rural Papua New Guineans: Composition, Diversity Patterns, and Ecological Processes

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    Inés Martínez

    2015-04-01

    Full Text Available Although recent research revealed an impact of westernization on diversity and composition of the human gut microbiota, the exact consequences on metacommunity characteristics are insufficiently understood, and the underlying ecological mechanisms have not been elucidated. Here, we have compared the fecal microbiota of adults from two non-industrialized regions in Papua New Guinea (PNG with that of United States (US residents. Papua New Guineans harbor communities with greater bacterial diversity, lower inter-individual variation, vastly different abundance profiles, and bacterial lineages undetectable in US residents. A quantification of the ecological processes that govern community assembly identified bacterial dispersal as the dominant process that shapes the microbiome in PNG but not in the US. These findings suggest that the microbiome alterations detected in industrialized societies might arise from modern lifestyle factors limiting bacterial dispersal, which has implications for human health and the development of strategies aimed to redress the impact of westernization.

  12. Riparian and aquatic habitats of the Pacific Northwest and southeast Alaska: ecology, management history, and potential management strategies.

    Science.gov (United States)

    Fred H. Everest; Gordon H. Reeves

    2007-01-01

    Management of riparian habitats is controversial because land use policies have historically emphasized economic values (e.g., timber production) at the expense of ecological and social values. Attempting to manage these valuable resources to attain the greatest combination of benefits has created a long-term controversy that continues to the present. Our analysis...

  13. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  14. [Evaluation of ecosystem service value and strategies for ecological design in land consolidation: a case of land consolidation project in Da'an City, Jilin Province, China].

    Science.gov (United States)

    Wang, Jun; Yan, Shen-Chun; Yu, Li; Zhang, Ya-Nan

    2014-04-01

    Land consolidation, as one of the major driving forces for the changes of land use/cover, has significant impacts on landscape patterns, ecological functions, and ecosystem services. In this paper, a land consolidation project conducted in Da'an City, Jinlin Province, China, was selected to evaluate the ecosystem service values before and after land consolidation at three spatial scales, i. e., village, town, and county. The results indicated that the land consolidation with the goal to increase the area of cultivated land might cause the decrease of the saline and alkaline land, grassland, and wetland. In addition, land consolidation resulted in the reduction of the total ecosystem service values at varying degree at the three scales. Compared to the pre-consolidation status, the total post-consolidation ecosystem service values at the village, town and county scales were 7.96, 843.01 and 1205.86 million yuan, and reduced by 10.5%, 14.2% and 33.1%, respectively. Based on the evaluation of ecosystem service value, strategies of landscape ecological design were discussed to improve the ecological functions and to provide the guidance for the sustainable development of land consolidation.

  15. The Genomic Sequence of the Oral Pathobiont Strain NI1060 Reveals Unique Strategies for Bacterial Competition and Pathogenicity.

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    Youssef Darzi

    Full Text Available Strain NI1060 is an oral bacterium responsible for periodontitis in a murine ligature-induced disease model. To better understand its pathogenicity, we have determined the complete sequence of its 2,553,982 bp genome. Although closely related to Pasteurella pneumotropica, a pneumonia-associated rodent commensal based on its 16S rRNA, the NI1060 genomic content suggests that they are different species thriving on different energy sources via alternative metabolic pathways. Genomic and phylogenetic analyses showed that strain NI1060 is distinct from the genera currently described in the family Pasteurellaceae, and is likely to represent a novel species. In addition, we found putative virulence genes involved in lipooligosaccharide synthesis, adhesins and bacteriotoxic proteins. These genes are potentially important for host adaption and for the induction of dysbiosis through bacterial competition and pathogenicity. Importantly, strain NI1060 strongly stimulates Nod1, an innate immune receptor, but is defective in two peptidoglycan recycling genes due to a frameshift mutation. The in-depth analysis of its genome thus provides critical insights for the development of NI1060 as a prime model system for infectious disease.

  16. Investigating Strategies for Sustainable Vegetable Food Crop System in Three Agro Ecological Zones of the Humid Tropics Area of Cameroon

    OpenAIRE

    TATA NGOME, Precillia Ijang; AFARI-SEFA, Victor; NTSOMBOH-NTSEFONG, Godswill; OKOLLE, Justin; BILLA, Samuel Fru; MOMA, Crescence; ATEMKENG FONJI, Maureen; NGOME, Ajebesone Francis

    2018-01-01

    Vegetable cultivation remains an essential component of local people’s livelihoods. However, marked trend shifts in the varieties of vegetables due to large-scale commercial vegetable farming of exotic varieties in the broader market economy have resulted in the gradual disappearance of biodiversity involving vital species. The present study examined the situation of vegetable crop farming in three agro-ecological zones of Cameroon. Data were collected from a random sample of 235 respondents ...

  17. [Ecology and ecologies].

    Science.gov (United States)

    Valera, Luca

    2011-01-01

    Ecology (from the Greek words οιχοσ, "house" and λογια "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

  18. The construction and use of bacterial DNA microarrays based on an optimized two-stage PCR strategy

    Directory of Open Access Journals (Sweden)

    Pesta David

    2003-06-01

    Full Text Available Abstract Background DNA microarrays are a powerful tool with important applications such as global gene expression profiling. Construction of bacterial DNA microarrays from genomic sequence data using a two-stage PCR amplification approach for the production of arrayed DNA is attractive because it allows, in principal, the continued re-amplification of DNA fragments and facilitates further utilization of the DNA fragments for additional uses (e.g. over-expression of protein. We describe the successful construction and use of DNA microarrays by the two-stage amplification approach and discuss the technical challenges that were met and resolved during the project. Results Chimeric primers that contained both gene-specific and shared, universal sequence allowed the two-stage amplification of the 3,168 genes identified on the genome of Synechocystis sp. PCC6803, an important prokaryotic model organism for the study of oxygenic photosynthesis. The gene-specific component of the primer was of variable length to maintain uniform annealing temperatures during the 1st round of PCR synthesis, and situated to preserve full-length ORFs. Genes were truncated at 2 kb for efficient amplification, so that about 92% of the PCR fragments were full-length genes. The two-stage amplification had the additional advantage of normalizing the yield of PCR products and this improved the uniformity of DNA features robotically deposited onto the microarray surface. We also describe the techniques utilized to optimize hybridization conditions and signal-to-noise ratio of the transcription profile. The inter-lab transportability was demonstrated by the virtual error-free amplification of the entire genome complement of 3,168 genes using the universal primers in partner labs. The printed slides have been successfully used to identify differentially expressed genes in response to a number of environmental conditions, including salt stress. Conclusions The technique detailed

  19. Recent advances in therapeutic recruitment of mammalian RNAi and bacterial CRISPR-Cas DNA interference pathways as emerging antiviral strategies.

    Science.gov (United States)

    Chin, Wei-Xin; Ang, Swee Kim; Chu, Justin Jang Hann

    2017-01-01

    In invertebrate eukaryotes and prokaryotes, respectively, the RNAi and clustered regularly interspaced short palindromic repeats-CRISPR-associated (CRISPR-Cas) pathways are highly specific and efficient RNA and DNA interference systems, and are well characterised as potent antiviral systems. It has become possible to recruit or reconstitute these pathways in mammalian cells, where they can be directed against desired host or viral targets. The RNAi and CRISPR-Cas systems can therefore yield ideal antiviral therapeutics, capable of specific and efficient viral inhibition with minimal off-target effects, but development of such therapeutics can be slow. This review covers recent advances made towards developing RNAi or CRISPR-Cas strategies for clinical use. These studies address the delivery, toxicity or target design issues that typically plague the in vivo or clinical use of these technologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Ecological suicide in microbes.

    Science.gov (United States)

    Ratzke, Christoph; Denk, Jonas; Gore, Jeff

    2018-05-01

    The growth and survival of organisms often depend on interactions between them. In many cases, these interactions are positive and caused by a cooperative modification of the environment. Examples are the cooperative breakdown of complex nutrients in microbes or the construction of elaborate architectures in social insects, in which the individual profits from the collective actions of her peers. However, organisms can similarly display negative interactions by changing the environment in ways that are detrimental for them, for example by resource depletion or the production of toxic byproducts. Here we find an extreme type of negative interactions, in which Paenibacillus sp. bacteria modify the environmental pH to such a degree that it leads to a rapid extinction of the whole population, a phenomenon that we call ecological suicide. Modification of the pH is more pronounced at higher population densities, and thus ecological suicide is more likely to occur with increasing bacterial density. Correspondingly, promoting bacterial growth can drive populations extinct whereas inhibiting bacterial growth by the addition of harmful substances-such as antibiotics-can rescue them. Moreover, ecological suicide can cause oscillatory dynamics, even in single-species populations. We found ecological suicide in a wide variety of microbes, suggesting that it could have an important role in microbial ecology and evolution.

  1. The Clinical Nutrition Research Agenda in Indonesia and beyond: ecological strategy for food in health care delivery.

    Science.gov (United States)

    Lukito, Widjaja; Wibowo, Lindawati; Wahlqvist, Mark L

    2017-06-01

    Despite progress with the food-associated health agenda in the public health and clinical domains, much remains to be done in Indonesia. There are reasons to be optimistic which include economic development, increasing literacy, progress towards universal health coverage and community organizational arrangements across the archipelago which focus on health through some 10,000 puskesmas. These community health centres are variably staffed with voluntary cadres from the community, bidans (nurses) and general medical practitioners. For more effective prevention and management of nutritionally-related health problems, innovative community and clinical nutrition research and expertise is required. With rapid urbanisation, the growth of the digital economy, increasing socio-economic inequity and climate change, there are imperatives for ecologically sustainable, nonemployment dependent livelihoods which provide energy, food, water, education and health care security. A relevant health care workforce will include those who research and practice clinical nutrition. Here we gather together an account of an extensive body of published and emerging literature which makes a case collectively for a more ecological approach to nutrition and health and how it might revitalise the Indonesian and other health care systems.

  2. Postviral Complications: Bacterial Pneumonia.

    Science.gov (United States)

    Prasso, Jason E; Deng, Jane C

    2017-03-01

    Secondary bacterial pneumonia after viral respiratory infection remains a significant source of morbidity and mortality. Susceptibility is mediated by a variety of viral and bacterial factors, and complex interactions with the host immune system. Prevention and treatment strategies are limited to influenza vaccination and antibiotics/antivirals respectively. Novel approaches to identifying the individuals with influenza who are at increased risk for secondary bacterial pneumonias are urgently needed. Given the threat of further pandemics and the heightened prevalence of these viruses, more research into the immunologic mechanisms of this disease is warranted with the hope of discovering new potential therapies. Published by Elsevier Inc.

  3. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  4. Mass culture strategy for bacterial yeast co-culture for degradation of petroleum hydrocarbons in marine environment.

    Science.gov (United States)

    Priya, Anchal; Mandal, Ajoy K; Ball, Andrew S; Manefield, Mike; Lal, Banwari; Sarma, Priyangshu M

    2015-11-15

    In the present study a metabolically versatile co-culture with two Bacilli and one yeast strain was developed using enrichment culture techniques. The developed co-culture had affinity to degrade both aliphatic and aromatic fractions of petroleum crude oil. Degradation kinetics was established for designing the fermentation protocol of the co-culture. The developed mass culture strategy led to achieve the reduction in surface tension (26dynescm(-1) from 69 dynescm(-1)) and degradation of 67% in bench scale experiments. The total crude oil degradation of 96% was achieved in 4000l of natural seawater after 28days without adding any nutrients. The survival of the augmented co-culture was maintained (10(9)cellsml(-1)) in contaminated marine environment. The mass culture protocol devised for the bioaugmentation was a key breakthrough that was subsequently used for pilot scale studies with 100l and 4000l of natural seawater for potential application in marine oil spills. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Industrial ecology.

    Science.gov (United States)

    Patel, C K

    1992-01-01

    Industrial ecology addresses issues that will impact future production, use, and disposal technologies; proper use of the concept should reduce significantly the resources devoted to potential remediation in the future. This cradle-to-reincarnation production philosophy includes industrial processes that are environmentally sound and products that are environmentally safe during use and economically recyclable after use without adverse impact on the environment or on the net cost to society. This will require an industry-university-government round table to set the strategy and agenda for progress. PMID:11607254

  6. Ecology of Fungus Gnats (Bradysia spp.) in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies.

    Science.gov (United States)

    Cloyd, Raymond A

    2015-04-09

    Fungus gnats (Bradysia spp.) are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems.

  7. Ecology of Fungus Gnats (Bradysia spp. in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies

    Directory of Open Access Journals (Sweden)

    Raymond A. Cloyd

    2015-04-01

    Full Text Available Fungus gnats (Bradysia spp. are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems.

  8. Anthropogenic ecological change and impacts on mosquito breeding and control strategies in salt-marshes, Northern Territory, Australia.

    Science.gov (United States)

    Jacups, Susan; Warchot, Allan; Whelan, Peter

    2012-06-01

    Darwin, in the tropical north of Australia, is subject to high numbers of mosquitoes and several mosquito-borne diseases. Many of Darwin's residential areas were built in close proximity to tidally influenced swamps, where long-term storm-water run-off from nearby residences into these swamps has led to anthropogenic induced ecological change. When natural wet-dry cycles were disrupted, bare mud-flats and mangroves were transformed into perennial fresh to brackish-water reed swamps. Reed swamps provided year-round breeding habitat for many mosquito species, such that mosquito abundance was less predictable and seasonally dependent, but constant and often occurring in plague proportions. Drainage channels were constructed throughout the wetlands to reduce pooled water during dry-season months. This study assesses the impact of drainage interventions on vegetation and mosquito ecology in three salt-marshes in the Darwin area. Findings revealed a universal decline in dry-season mosquito abundance in each wetland system. However, some mosquito species increased in abundance during wet-season months. Due to the high expense and potentially detrimental environmental impacts of ecosystem and non-target species disturbance, large-scale modifications such as these are sparingly undertaken. However, our results indicate that some large scale environmental modification can assist the process of wetland restoration, as appears to be the case for these salt marsh systems. Drainage in all three systems has been restored to closer to their original salt-marsh ecosystems, while reducing mosquito abundances, thereby potentially lowering the risk of vector-borne disease transmission and mosquito pest biting problems.

  9. Distributed and dynamic modelling of hydrology, phosphorus and ecology in the Hampshire Avon and Blashford Lakes: evaluating alternative strategies to meet WFD standards.

    Science.gov (United States)

    Whitehead, P G; Jin, L; Crossman, J; Comber, S; Johnes, P J; Daldorph, P; Flynn, N; Collins, A L; Butterfield, D; Mistry, R; Bardon, R; Pope, L; Willows, R

    2014-05-15

    The issues of diffuse and point source phosphorus (P) pollution in the Hampshire Avon and Blashford Lakes are explored using a catchment model of the river system. A multibranch, process based, dynamic water quality model (INCA-P) has been applied to the whole river system to simulate water fluxes, total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations and ecology. The model has been used to assess impacts of both agricultural runoff and point sources from waste water treatment plants (WWTPs) on water quality. The results show that agriculture contributes approximately 40% of the phosphorus load and point sources the other 60% of the load in this catchment. A set of scenarios have been investigated to assess the impacts of alternative phosphorus reduction strategies and it is shown that a combined strategy of agricultural phosphorus reduction through either fertiliser reductions or better phosphorus management together with improved treatment at WWTPs would reduce the SRP concentrations in the river to acceptable levels to meet the EU Water Framework Directive (WFD) requirements. A seasonal strategy for WWTP phosphorus reductions would achieve significant benefits at reduced cost. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Approach and strategy for performing ecological risk assessments for the US Department of Energy`s Oak Ridge Reservation: 1995 revision

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II; Sample, B.E.; Jones, D.S.; Ashwood, T.L.; Loar, J.M.

    1995-09-01

    The purpose of this document is to provide guidance for planning and performing ecological risk assessments (ERAs) on the Oak Ridge Reservation (ORR). It is the third such document prepared for this purpose. The first ecorisk strategy document described the ERA process and presented a tiered approach to ERAs appropriate to complex sites. The first revision was necessitated by the considerable progress that has been made by the parties to the Federal Facilities Agreement (FFA) for the ORR in resolving specific issues relating to ERA as a result of a series of data quality objectives (DQOs) meetings. The tiered approach to ERAs as recommended in the first document was implemented, generic conceptual models were developed, and a general approach for developing ecological assessment endpoints and measurement endpoints was agreed upon. This revision is necessitated by comments from the US Environmental Protection Agency`s Region IV and the Tennessee Department of Environment and Conservation (TDEC) which clarified and modified the positions taken during the DQO process. In particular, support for the collection of data that would support ERAs for all OUs on the ORR have been withdrawn. Therefore, the work plan developed to fill the reservation-wide data needs identified in the DQO process has also been withdrawn, and portions that are still relevant have been incorporated into this document. The reader should be aware that this guidance is complex and lengthy because it attempts to cover all the reasonable contingencies that were considered to be potentially important to the FFA parties.

  11. ECOLOGICAL CLASSIFICATION OF LAND AND ECOSYSTEM MAPPING. TOWARDS THE IMPLEMENTATION OF ACTION 5 OF THE EUROPEAN BIODIVERSITY STRATEGY TO 2020 IN ITALY.

    Directory of Open Access Journals (Sweden)

    G. Capotorti

    2014-04-01

    Full Text Available The aim of the present paper is to illustrate the basic data and the methodological approach proposed for the implementation of Action 5 of the European Biodiversity Strategy in Italy. In particular, it focuses on a model for ecosystem mapping and characterisation at the country level that has been built with the interdisciplinary involvement of geobotanists, functional ecologists, forest scientists and zoologists. The first operational steps of the model are based on the cartographic integration between potential natural vegetation, biogeographic regions, and land cover maps. The final step entails characterising the mapped ecosystems in terms of Habitats Directive, local occurrence of threatened plant species and faunal components. The model is going to be tested in Italy, but should also be applied elsewhere in Mediterranean Europe, especially in those countries that have a comparable ecological complexity.

  12. 16S rRNA gene metabarcoding and TEM reveals different ecological strategies within the genus Neogloboquadrina (planktonic foraminifer.

    Directory of Open Access Journals (Sweden)

    Clare Bird

    Full Text Available Uncovering the complexities of trophic and metabolic interactions among microorganisms is essential for the understanding of marine biogeochemical cycling and modelling climate-driven ecosystem shifts. High-throughput DNA sequencing methods provide valuable tools for examining these complex interactions, although this remains challenging, as many microorganisms are difficult to isolate, identify and culture. We use two species of planktonic foraminifera from the climatically susceptible, palaeoceanographically important genus Neogloboquadrina, as ideal test microorganisms for the application of 16S rRNA gene metabarcoding. Neogloboquadrina dutertrei and Neogloboquadrina incompta were collected from the California Current and subjected to either 16S rRNA gene metabarcoding, fluorescence microscopy, or transmission electron microscopy (TEM to investigate their species-specific trophic interactions and potential symbiotic associations. 53-99% of 16S rRNA gene sequences recovered from two specimens of N. dutertrei were assigned to a single operational taxonomic unit (OTU from a chloroplast of the phylum Stramenopile. TEM observations confirmed the presence of numerous intact coccoid algae within the host cell, consistent with algal symbionts. Based on sequence data and observed ultrastructure, we taxonomically assign the putative algal symbionts to Pelagophyceae and not Chrysophyceae, as previously reported in this species. In addition, our data shows that N. dutertrei feeds on protists within particulate organic matter (POM, but not on bacteria as a major food source. In total contrast, of OTUs recovered from three N. incompta specimens, 83-95% were assigned to bacterial classes Alteromonadales and Vibrionales of the order Gammaproteobacteria. TEM demonstrates that these bacteria are a food source, not putative symbionts. Contrary to the current view that non-spinose foraminifera are predominantly herbivorous, neither N. dutertrei nor N. incompta

  13. Marine Ecological Environment Management Based on Ecological Compensation Mechanisms

    Directory of Open Access Journals (Sweden)

    Qunzhen Qu

    2016-12-01

    Full Text Available The level of marine environmental management is a key factor in the successful implementation of marine power strategies. The improvement in management levels of marine environments requires innovation in marine management. In other words, the transformation of marine environmental management into marine ecological environment management must be done in order to achieve sustainable development of the marine economy. As an environmental economic policy that combines both administrative and market measures, ecological compensation mechanisms have significant advantages in marine ecological environment management. Based on the study of the current development of ecological compensation mechanisms in China, through the analysis of the connotation of marine ecological civilization, existing marine ecological protection practices and marine environmental management methods, this paper posits that the current marine ecological environment management in China should be established on the basis of ecological compensation mechanisms. At present, a lack of laws and regulations for overall marine ecological environment management is the key factor restricting the practice of marine ecological environment management. Therefore, it is necessary to explore the current path of marine ecological environment management in China from the perspective of the construction of legal system of ecological compensation law, the establishment of ecological compensation fees, ecological taxes and ecological compensation fund systems, and the clear status for a marine ecological management and supervision body.

  14. Organic Pollutants in Shale Gas Flowback and Produced Waters: Identification, Potential Ecological Impact, and Implications for Treatment Strategies

    Science.gov (United States)

    2017-01-01

    Organic contaminants in shale gas flowback and produced water (FPW) are traditionally expressed as total organic carbon (TOC) or chemical oxygen demand (COD), though these parameters do not provide information on the toxicity and environmental fate of individual components. This review addresses identification of individual organic contaminants in FPW, and stresses the gaps in the knowledge on FPW composition that exist so far. Furthermore, the risk quotient approach was applied to predict the toxicity of the quantified organic compounds for fresh water organisms in recipient surface waters. This resulted in an identification of a number of FPW related organic compounds that are potentially harmful namely those compounds originating from shale formations (e.g., polycyclic aromatic hydrocarbons, phthalates), fracturing fluids (e.g., quaternary ammonium biocides, 2-butoxyethanol) and downhole transformations of organic compounds (e.g., carbon disulfide, halogenated organic compounds). Removal of these compounds by FPW treatment processes is reviewed and potential and efficient abatement strategies are defined. PMID:28376616

  15. Responsibility for the Ecological Crisis

    Science.gov (United States)

    Wright, Richard T.

    1970-01-01

    Critically analyzes the thesis of Christian responsibility for the ecological crisis and leads to its rejection. Present day environmental misuse results from greed, carelessness, and ignorance." Advocates ecological strategy of corrective action, with supplementary theological strategy" for church-influenced citizens. (AL)

  16. Sampling Terrestrial Environments for Bacterial Polyketides

    Directory of Open Access Journals (Sweden)

    Patrick Hill

    2017-04-01

    Full Text Available Bacterial polyketides are highly biologically active molecules that are frequently used as drugs, particularly as antibiotics and anticancer agents, thus the discovery of new polyketides is of major interest. Since the 1980s discovery of polyketides has slowed dramatically due in large part to the repeated rediscovery of known compounds. While recent scientific and technical advances have improved our ability to discover new polyketides, one key area has been under addressed, namely the distribution of polyketide-producing bacteria in the environment. Identifying environments where producing bacteria are abundant and diverse should improve our ability to discover (bioprospect new polyketides. This review summarizes for the bioprospector the state-of-the-field in terrestrial microbial ecology. It provides insight into the scientific and technical challenges limiting the application of microbial ecology discoveries for bioprospecting and summarizes key developments in the field that will enable more effective bioprospecting. The major recent efforts by researchers to sample new environments for polyketide discovery is also reviewed and key emerging environments such as insect associated bacteria, desert soils, disease suppressive soils, and caves are highlighted. Finally strategies for taking and characterizing terrestrial samples to help maximize discovery efforts are proposed and the inclusion of non-actinomycetal bacteria in any terrestrial discovery strategy is recommended.

  17. Ecological carbon sequestration via wood harvest and storage (WHS): Can it be a viable climate and energy strategy?

    Science.gov (United States)

    Zeng, N.; Zaitchik, B. F.; King, A. W.; Wullschleger, S. D.

    2016-12-01

    A carbon sequestration strategy is proposed in which forests are sustainably managed to optimal carbon productivity, and a fraction of the wood is selectively harvested and stored to prevent decomposition under anaerobic, dry or cold conditions. Because a large flux of CO2 is constantly assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. The live trees serve as a `carbon scrubber' or `carbon remover' that provides continuous sequestration (negative emissions). The stored wood is a semi-permanent carbon sink, but also serves as a `biomass/bioenergy reserve' that could be utilized in the future.Based on forest coarse wood production rate, land availability, bioconservation and other practical constraints, we estimate a carbon sequestration potential for wood harvest and storage (WHS) 1-3 GtC y-1. The implementation of such a scheme at our estimated lower value of 1 GtC y-1 would imply a doubling of the current world wood harvest rate. This can be achieved by harvesting wood at a modest harvesting intensity of 1.2 tC ha-1 y-1, over a forest area of 8 Mkm2 (800 Mha). To achieve the higher value of 3 GtC y-1, forests need to be managed this way on half of the world's forested land, or on a smaller area but with higher harvest intensity. However, the actual implementation may face challenges that vary regionally. We propose `carbon sequestration and biomass farms' in the tropical deforestation frontiers with mixed land use for carbon, energy, agriculture, as well as conservation. In another example, the forests damaged by insect infestation could be thinned to reduce fire and harvested for carbon sequestration.We estimate a cost of $10-50/tCO2 for harvest and storage around the landing site. The technique is low tech, distributed and reversible. We compare the potential of WHS with a number of other carbon sequestration methods. We will also show its impact on future land carbon sink

  18. Integrating feeding behavior, ecological data, and DNA barcoding to identify developmental differences in invertebrate foraging strategies in wild white-faced capuchins (Cebus capucinus).

    Science.gov (United States)

    Mallott, Elizabeth K; Garber, Paul A; Malhi, Ripan S

    2017-02-01

    Invertebrate foraging strategies in nonhuman primates often require complex extractive foraging or prey detection techniques. As these skills take time to master, juveniles may have reduced foraging efficiency or concentrate their foraging efforts on easier to acquire prey than adults. We use DNA barcoding, behavioral observations, and ecological data to assess age-based differences in invertebrate prey foraging strategies in a group of white-faced capuchins (Cebus capucinus) in northeastern Costa Rica. Invertebrate availability was monitored using canopy traps and sweep netting. Fecal samples were collected from adult female, adult male, and juvenile white-faced capuchins (n = 225). COI mtDNA sequences were compared with known sequences in GenBank and the Barcode of Life Database. Frequencies of Lepidoptera and Hymenoptera consumption were higher in juveniles than in adults. A significantly smaller proportion of juvenile fecal samples contained Gryllidae and Cercopidae sequences, compared with adults (0% and 4.2% vs. 4.6% and 12.5%), and a significantly larger proportion contained Tenthredinidae, Culicidae, and Crambidae (5.6%, 9.7%, and 5.6% vs. 1.3%, 0.7%, and 1.3%). Juveniles spent significantly more time feeding and foraging than adults, and focused their foraging efforts on prey that require different skills to capture or extract. Arthropod availability was not correlated with foraging efficiency, and the rate of consumption of specific orders of invertebrates was not correlated with the availability of those same taxa. Our data support the hypothesis that juveniles are concentrating their foraging efforts on different prey than adults, potentially focusing their foraging efforts on more easily acquired types of prey. © 2016 Wiley Periodicals, Inc.

  19. Bacterial prostatitis.

    Science.gov (United States)

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  20. Bacterial Vaginosis

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  1. European ecological networks and greenways

    DEFF Research Database (Denmark)

    Kristiansen, Ib; Jongman, Rob H.G.; Kulvik, Mart

    2004-01-01

    renewed. Within the framework of nature conservation, the notion of an ecological network has become increasingly important. Throughout Europe, regional and national approaches are in different phases of development, which are all based on recent landscape ecological principles. Ecological networks......In the context of European integration, networks are becoming increasingly important in both social and ecological sense. Since the beginning of the 1990s, societal and scientific exchanges are being restructured as the conceptual approaches towards new nature conservation strategies have been....... This complex interaction between cultural and natural features results in quite different ways for the elaboration of ecological networks and greenways....

  2. Ecological aspects influencing the implementation of inclusive ...

    African Journals Online (AJOL)

    Keywords: Assessment and Support Strategy, barriers to learning, ecological model, identification, inclusive ..... impedes the management of these learners in the mainstream schools. ..... An ecological systems theory perspective on youth.

  3. Convergent bacterial microbiotas in the fungal agricultural systems of insects.

    Science.gov (United States)

    Aylward, Frank O; Suen, Garret; Biedermann, Peter H W; Adams, Aaron S; Scott, Jarrod J; Malfatti, Stephanie A; Glavina del Rio, Tijana; Tringe, Susannah G; Poulsen, Michael; Raffa, Kenneth F; Klepzig, Kier D; Currie, Cameron R

    2014-11-18

    The ability to cultivate food is an innovation that has produced some of the most successful ecological strategies on the planet. Although most well recognized in humans, where agriculture represents a defining feature of civilization, species of ants, beetles, and termites have also independently evolved symbioses with fungi that they cultivate for food. Despite occurring across divergent insect and fungal lineages, the fungivorous niches of these insects are remarkably similar, indicating convergent evolution toward this successful ecological strategy. Here, we characterize the microbiota of ants, beetles, and termites engaged in nutritional symbioses with fungi to define the bacterial groups associated with these prominent herbivores and forest pests. Using culture-independent techniques and the in silico reconstruction of 37 composite genomes of dominant community members, we demonstrate that different insect-fungal symbioses that collectively shape ecosystems worldwide have highly similar bacterial microbiotas comprised primarily of the genera Enterobacter, Rahnella, and Pseudomonas. Although these symbioses span three orders of insects and two phyla of fungi, we show that they are associated with bacteria sharing high whole-genome nucleotide identity. Due to the fine-scale correspondence of the bacterial microbiotas of insects engaged in fungal symbioses, our findings indicate that this represents an example of convergence of entire host-microbe complexes. The cultivation of fungi for food is a behavior that has evolved independently in ants, beetles, and termites and has enabled many species of these insects to become ecologically important and widely distributed herbivores and forest pests. Although the primary fungal cultivars of these insects have been studied for decades, comparatively little is known of their bacterial microbiota. In this study, we show that diverse fungus-growing insects are associated with a common bacterial community composed of the

  4. Ecology-driven stereotypes override race stereotypes

    OpenAIRE

    Williams, Keelah E. G.; Sng, Oliver; Neuberg, Steven L.

    2015-01-01

    Ecological features shape people’s goals, strategies, and behaviors. Our research suggests that social perceivers possess a lay understanding of ecology’s influence on behavior, resulting in ecology-driven stereotypes. Moreover, because race is confounded with ecology in the United States, Americans’ stereotypes about racial groups may actually reflect their stereotypes about these groups’ presumed home ecologies. In a series of studies, we demonstrate that (i) individuals possess ecology-dri...

  5. BACTERIAL CONSORTIUM

    Directory of Open Access Journals (Sweden)

    Payel Sarkar

    2013-01-01

    Full Text Available Petroleum aromatic hydrocarbons like benzen e, toluene, ethyl benzene and xylene, together known as BTEX, has almost the same chemical structure. These aromatic hydrocarbons are released as pollutants in th e environment. This work was taken up to develop a solvent tolerant bacterial cons ortium that could degrade BTEX compounds as they all share a common chemical structure. We have isolated almost 60 different types of bacterial strains from different petroleum contaminated sites. Of these 60 bacterial strains almost 20 microorganisms were screene d on the basis of capability to tolerate high concentration of BTEX. Ten differe nt consortia were prepared and the compatibility of the bacterial strains within the consortia was checked by gram staining and BTEX tolerance level. Four successful mi crobial consortia were selected in which all the bacterial strains concomitantly grew in presence of high concentration of BTEX (10% of toluene, 10% of benzene 5% ethyl benzene and 1% xylene. Consortium #2 showed the highest growth rate in pr esence of BTEX. Degradation of BTEX by consortium #2 was monitored for 5 days by gradual decrease in the volume of the solvents. The maximum reduction observed wa s 85% in 5 days. Gas chromatography results also reveal that could completely degrade benzene and ethyl benzene within 48 hours. Almost 90% degradation of toluene and xylene in 48 hours was exhibited by consortium #2. It could also tolerate and degrade many industrial solvents such as chloroform, DMSO, acetonitrile having a wide range of log P values (0.03–3.1. Degradation of aromatic hydrocarbon like BTEX by a solvent tolerant bacterial consortium is greatly significant as it could degrade high concentration of pollutants compared to a bacterium and also reduces the time span of degradation.

  6. Ecology, Epidemiology and Disease Management of Ralstonia syzygii in Indonesia.

    Science.gov (United States)

    Safni, Irda; Subandiyah, Siti; Fegan, Mark

    2018-01-01

    Ralstonia solanacearum species complex phylotype IV strains, which have been primarily isolated from Indonesia, Australia, Japan, Korea, and Malaysia, have undergone recent taxonomic and nomenclatural changes to be placed in the species Ralstonia syzygii . This species contains three subspecies; Ralstonia syzygii subsp. syzygii , a pathogen causing Sumatra disease of clove trees in Indonesia, Ralstonia syzygii subsp. indonesiensis , the causal pathogen of bacterial wilt disease on a wide range of host plants, and Ralstonia syzygii subsp. celebesensis , the causal pathogen of blood disease on Musa spp. In Indonesia, these three subspecies have devastated the cultivation of susceptible host plants which have high economic value. Limited knowledge on the ecology and epidemiology of the diseases has hindered the development of effective control strategies. In this review, we provide insights into the ecology, epidemiology and disease control of these three subspecies of Ralstonia syzygii .

  7. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  8. Bacterial mycophagy: definition and diagnosis of a unique bacterial-fungal interaction

    NARCIS (Netherlands)

    Leveau, J.H.J.; Preston, G.M.

    2008-01-01

    This review analyses the phenomenon of bacterial mycophagy, which we define as a set of phenotypic behaviours that enable bacteria to obtain nutrients from living fungi and thus allow the conversion of fungal into bacterial biomass. We recognize three types of bacterial strategies to derive

  9. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    , which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters...

  10. Bacterial meningitis

    NARCIS (Netherlands)

    Heckenberg, Sebastiaan G. B.; Brouwer, Matthijs C.; van de Beek, Diederik

    2014-01-01

    Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained,

  11. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation,

  12. Bacterial stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Bacterial stress. Physicochemical and chemical parameters: temperature, pressure, pH, salt concentration, oxygen, irradiation. Nutritional depravation: nutrient starvation, water shortage. Toxic compounds: Antibiotics, heavy metals, toxins, mutagens. Interactions with other cells: ...

  13. Dynamic Effects of Biochar on the Bacterial Community Structure in Soil Contaminated with Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Song, Yang; Bian, Yongrong; Wang, Fang; Xu, Min; Ni, Ni; Yang, Xinglun; Gu, Chenggang; Jiang, Xin

    2017-08-16

    Amending soil with biochar is an effective soil remediation strategy for organic contaminants. This study investigated the dynamic effects of wheat straw biochar on the bacterial community structure during remediation by high-throughput sequencing. The wheat straw biochar amended into the soil significantly reduced the bioavailability and toxicity of polycyclic aromatic hydrocarbons (PAHs). Biochar amendment helped to maintain the bacterial diversity in the PAH-contaminated soil. The relationship between the immobilization of PAHs and the soil bacterial diversity fit a quadratic model. Before week 12 of the incubation, the incubation time was the main factor contributing to the changes in the soil bacterial community structure. However, biochar greatly affected the bacterial community structure after 12 weeks of amendment, and the effects were dependent upon the biochar type. Amendment with biochar mainly facilitated the growth of rare bacterial genera (relative abundance of 0.01-1%) in the studied soil. Therefore, the application of wheat straw biochar into PAH-contaminated soil can reduce the environmental risks of PAHs and benefit the soil microbial ecology.

  14. Bioaugmentation of thiabendazole-contaminated soils from a wastewater disposal site: Factors driving the efficacy of this strategy and the diversity of the indigenous soil bacterial community.

    Science.gov (United States)

    Papadopoulou, Evangelia S; Genitsaris, Savvas; Omirou, Michalis; Perruchon, Chiara; Stamatopoulou, Anastasia; Ioannides, Ioannis; Karpouzas, Dimitrios G

    2018-02-01

    The application of the fungicide thiabendazole (TBZ) in fruit packaging plants (FPP) results in the production of effluents which are often disposed in adjacent field sites. These require remediation to prevent further environmental dispersal of TBZ. We assessed the bioaugmentation potential of a newly isolated TBZ-degrading bacterial consortium in a naturally contaminated soil (NCS) exhibiting a natural gradient of TBZ levels (12000, 400, 250 and 12 mg kg -1 ). The effect of aging on bioaugmentation efficacy was comparatively tested in a soil with similar physicochemical properties and soil microbiota, which was artificially, contaminated with the same TBZ levels (ACS). The impact of bioaugmentation and TBZ on the bacterial diversity in the NCS was explored via amplicon sequencing. Bioaugmentation effectively removed TBZ from both soils at levels up to 400 mg kg -1 but failed at the highest contamination level (12000 mg kg -1 ). Dissipation of TBZ in bioaugmented samples showed a concentration-dependent pattern, while aging of TBZ had a slight effect on bioaugmentation efficiency. Bioaugmentation had no impact on the soil bacterial diversity, in contrast to TBZ contamination. Soils from the hotspots of TBZ contamination (12000 mg kg -1 ) showed a drastically lower α-diversity driven by the dominance of β- and γ-proteobacteria at the expense of all other bacterial phyla, especially Actinobacteria. Overall, bioaugmentation with specialized microbial inocula could be an effective solution for the recovery of disposal sites contaminated with persistent chemicals like TBZ. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

  16. Balanced Fertilization Decreases Environmental Filtering on Soil Bacterial Community Assemblage in North China

    Directory of Open Access Journals (Sweden)

    Youzhi Feng

    2017-12-01

    Full Text Available Although increasing evidences have emerged for responses of soil microorganisms to fertilizations, the knowledge regarding community assemblages that cause variations in composition is still lacking, as well as the possible feedback to soil fertility. Phylogenetic conservatism of species indicates their similar environmental preferences and/or function traits and phylogenetic signals further can infer community assemblages and influenced ecological processes. Here, we calculated the mean pairwise phylogenetic distance and nearest relative index, characterizing phylogenetic signal and the undergone ecological process to evaluate the community assembly of soil bacterial phylotypes in 20-year fertilized soils. The bacterial community assembly is structured by environmental filtering, regardless of fertilization regime. Soil phosphorous (P availability imposes selection on community assemblage and influences their community turnover among fertilizations. When P nutrient lacks, the effect of environmental filtering becomes stronger, hence bacterial functional traits become more coherent; this process results into increased intraspecific interactions characterized by co-occurrence network analysis. In contrast, when P nutrient becomes abundant, the environmental selection is mitigated; function traits are evened. This process reduces intraspecific interactions and increases carbon sequestration efficiency, which is finally of great favor to the increases in soil fertility. This study has made the first attempt, at the bacterial level, to understand how fertilization affects agroecosystems. When more phylogenetic information on how nutrient cycling-related microbes respond to fertilization becomes available, the systematic knowledge will eventually provide guidance to optimal fertilization strategies.

  17. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  18. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    , and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... to translate positivist readings of the environment and hermeneutical perspectives on socioecological interaction into a common framework or terminology....

  19. The immune strategy and stress response of the Mediterranean species of the Bemisia tabaci complex to an orally delivered bacterial pathogen.

    Directory of Open Access Journals (Sweden)

    Chang-Rong Zhang

    Full Text Available BACKGROUND: The whitefly, Bemisia tabaci, a notorious agricultural pest, has complex relationships with diverse microbes. The interactions of the whitefly with entomopathogens as well as its endosymbionts have received great attention, because of their potential importance in developing novel whitefly control technologies. To this end, a comprehensive understanding on the whitefly defense system is needed to further decipher those interactions. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a comprehensive investigation of the whitefly's defense responses to infection, via oral ingestion, of the pathogen, Pseudomonas aeruginosa, using RNA-seq technology. Compared to uninfected whiteflies, 6 and 24 hours post-infected whiteflies showed 1,348 and 1,888 differentially expressed genes, respectively. Functional analysis of the differentially expressed genes revealed that the mitogen associated protein kinase (MAPK pathway was activated after P. aeruginosa infection. Three knottin-like antimicrobial peptide genes and several components of the humoral and cellular immune responses were also activated, indicating that key immune elements recognized in other insect species are also important for the response of B. tabaci to pathogens. Our data also suggest that intestinal stem cell mediated epithelium renewal might be an important component of the whitefly's defense against oral bacterial infection. In addition, we show stress responses to be an essential component of the defense system. CONCLUSIONS/SIGNIFICANCE: We identified for the first time the key immune-response elements utilized by B. tabaci against bacterial infection. This study provides a framework for future research into the complex interactions between whiteflies and microbes.

  20. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the benefits...... and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial communities...

  1. Ecology-driven stereotypes override race stereotypes

    Science.gov (United States)

    Williams, Keelah E. G.; Sng, Oliver; Neuberg, Steven L.

    2016-01-01

    Why do race stereotypes take the forms they do? Life history theory posits that features of the ecology shape individuals’ behavior. Harsh and unpredictable (“desperate”) ecologies induce fast strategy behaviors such as impulsivity, whereas resource-sufficient and predictable (“hopeful”) ecologies induce slow strategy behaviors such as future focus. We suggest that individuals possess a lay understanding of ecology’s influence on behavior, resulting in ecology-driven stereotypes. Importantly, because race is confounded with ecology in the United States, we propose that Americans’ stereotypes about racial groups actually reflect stereotypes about these groups’ presumed home ecologies. Study 1 demonstrates that individuals hold ecology stereotypes, stereotyping people from desperate ecologies as possessing faster life history strategies than people from hopeful ecologies. Studies 2–4 rule out alternative explanations for those findings. Study 5, which independently manipulates race and ecology information, demonstrates that when provided with information about a person’s race (but not ecology), individuals’ inferences about blacks track stereotypes of people from desperate ecologies, and individuals’ inferences about whites track stereotypes of people from hopeful ecologies. However, when provided with information about both the race and ecology of others, individuals’ inferences reflect the targets’ ecology rather than their race: black and white targets from desperate ecologies are stereotyped as equally fast life history strategists, whereas black and white targets from hopeful ecologies are stereotyped as equally slow life history strategists. These findings suggest that the content of several predominant race stereotypes may not reflect race, per se, but rather inferences about how one’s ecology influences behavior. PMID:26712013

  2. THE EFFECTS OF TEMPERATURE AND pH ON BACTERIAL ...

    African Journals Online (AJOL)

    PROF EKWUEME

    The effect of temperature and pH on bacterial degradation of latex paint under humid condition by .... blade and plastic bags as described by Okpokwasili and. Ituen(1996) and .... provided different ecological niche for bacteria at favourable ...

  3. Environmental strategy

    DEFF Research Database (Denmark)

    Zabkar, Vesna; Cater, Tomaz; Bajde, Domen

    2013-01-01

    perspective, appropriate environmental strategies in compliance with environmental requirements aim at building competitive advantages through sustainable development. There is no universal “green” strategy that would be appropriate for each company, regardless of its market requirements and competitive......Environmental issues and the inclusion of environmental strategies in strategic thinking is an interesting subject of investigation. In general, managerial practices organized along ecologically sound principles contribute to a more environmentally sustainable global economy. From the managerial...

  4. Bacterial mitosis

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... act together to generate the force required for plasmid movement during segregation. ParR protein binds cooperatively to the centromeric parC DNA region, thereby forming a complex that interacts with the filament-forming actin-like ParM protein in an ATP-dependent manner, suggesting that plasmid...

  5. 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...

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

    Directory of Open Access Journals (Sweden)

    Erin A McKenney

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

  7. The Participatory Construction of Agro-Ecological Knowledge As A Soil Conservation Strategy In The Mountain Region of Rio de Janeiro State (Brazil

    Directory of Open Access Journals (Sweden)

    de Assis Renato Linhares

    2018-02-01

    Full Text Available Agriculture in the mountain region of Rio de Janeiro State is characterized by intensive soil use and input. Such mountainous environments are vulnerable to climate events; thus, the current article presents a report on methods applied to exchange academic and traditional knowledge. The aim is to expand farmers’ perception about the need of implementing agro-ecological practices, mainly soil management practices, which are important for agricultural sustainability in mountainous environments. The study was conducted in a Nova Friburgo family production unit, in the mountain region of Rio de Janeiro State (Brazil. It consisted of implementing three observation and soil organic-matter management units. The idea was to reduce the incidence of clubroot of crucifers disease caused by Plasmidiophora brassicae. The soil fauna was discussed with local farmers, with emphasis on the association between ecological processes and soil management. The present study improved the discussion with farmers and the need of introducing other innovative conservation practices such as no-tillage system and participatory research based on agro-ecological propositions.

  8. Adaptive Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  9. Bacterial Actins.

    Science.gov (United States)

    Izoré, Thierry; van den Ent, Fusinita

    2017-01-01

    A diverse set of protein polymers, structurally related to actin filaments contributes to the organization of bacterial cells as cytomotive or cytoskeletal filaments. This chapter describes actin homologs encoded by bacterial chromosomes. MamK filaments, unique to magnetotactic bacteria, help establishing magnetic biological compasses by interacting with magnetosomes. Magnetosomes are intracellular membrane invaginations containing biomineralized crystals of iron oxide that are positioned by MamK along the long-axis of the cell. FtsA is widespread across bacteria and it is one of the earliest components of the divisome to arrive at midcell, where it anchors the cell division machinery to the membrane. FtsA binds directly to FtsZ filaments and to the membrane through its C-terminus. FtsA shows altered domain architecture when compared to the canonical actin fold. FtsA's subdomain 1C replaces subdomain 1B of other members of the actin family and is located on the opposite side of the molecule. Nevertheless, when FtsA assembles into protofilaments, the protofilament structure is preserved, as subdomain 1C replaces subdomain IB of the following subunit in a canonical actin filament. MreB has an essential role in shape-maintenance of most rod-shaped bacteria. Unusually, MreB filaments assemble from two protofilaments in a flat and antiparallel arrangement. This non-polar architecture implies that both MreB filament ends are structurally identical. MreB filaments bind directly to membranes where they interact with both cytosolic and membrane proteins, thereby forming a key component of the elongasome. MreB filaments in cells are short and dynamic, moving around the long axis of rod-shaped cells, sensing curvature of the membrane and being implicated in peptidoglycan synthesis.

  10. Bacterial Diversity across Individual Lichens▿ †

    Science.gov (United States)

    Mushegian, Alexandra A.; Peterson, Celeste N.; Baker, Christopher C. M.; Pringle, Anne

    2011-01-01

    Symbioses are unique habitats for bacteria. We surveyed the spatial diversity of bacterial communities across multiple individuals of closely related lichens using terminal restriction fragment length polymorphism (T-RFLP) and pyrosequencing. Centers of lichens house richer, more consistent assemblages than species-poor and compositionally disparate lichen edges, suggesting that ecological succession plays a role in structuring these communities. PMID:21531831

  11. Enhanced Tolerance to Cadmium in Bacterial-Fungal Co-Cultures as a Strategy for Metal Biorecovery from e-Waste

    Directory of Open Access Journals (Sweden)

    Geremia Losa

    2018-03-01

    Full Text Available We investigated a microbe-based approach to be used for the biorecovery of valuable metals from e-waste. E-waste is a heterogeneous matrix at the microbial scale. Therefore, this study aims at taking advantage of bacterial-fungal (BF interactions in order to mobilize and immobilize a selected metal present in e-waste. We used cadmium (Cd and a selection of Cd-tolerant microorganisms from our culture collection or isolated from a naturally cadmium-contaminated soil. Several experiments were designed in order to use the synergistic bioremediation capabilities of BF couples to mobilize and immobilize Cd from a culture medium. Initial results showed that the selected synergistic BF couples are more tolerant to Cd concentrations than the organisms alone. However, setting the conditions leading to effective immobilization of this toxic metal still need further work. Using microbial consortia rather than single species represents an innovative alternative to traditional bioremediation approaches for the development of new biotechnological approaches in urban mining.

  12. Ecological macroeconomics

    DEFF Research Database (Denmark)

    Røpke, Inge

    2013-01-01

    by a more theoretical debate and increased interaction between the heterodox schools of ecological economics and post-Keynesian economics. In addition, both the degrowth community and the research community organized around sustainable transitions of socio-technical systems have contributed to discussions...... on how to reconcile environmental and social concerns. Based on this broad variety of pieces in a jigsaw puzzle, a new ecological macroeconomics is emerging, but the contours are still vague. This chapter seeks to outline some of this topography and to add a few pieces of its own by highlighting the need...... to shift resources from consumption to investment and describing the role of consumer-citizens in such a change. The chapter starts by identifying the problems and challenges for an ecological macroeconomics. The next section outlines some of the shortcomings of traditional macroeconomics...

  13. Introduction: Experimental Green Strategies

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    Defining new ways in which archietcts are responding to the challenge of creating sustainable architecture , Experimental Green Strategies present a state of the art in applied ecological architectural research.......Defining new ways in which archietcts are responding to the challenge of creating sustainable architecture , Experimental Green Strategies present a state of the art in applied ecological architectural research....

  14. Ecology and pathogenicity of gastrointestinal Streptococcus bovis.

    Science.gov (United States)

    Herrera, Paul; Kwon, Young Min; Ricke, Steven C

    2009-01-01

    Streptococcus bovis is an indigenous resident in the gastrointestinal tracts of both humans and animals. S. bovis is one of the major causes of bacterial endocarditis and has been implicated in the incidence of human colon cancer, possibly due to chronic inflammatory response at the site of intestinal colonization. Certain feeding regimens in ruminants can lead to overgrowth of S. bovis in the rumen, resulting in the over-production of lactate and capsular polysaccharide causing acute ruminal acidosis and bloat, respectively. There are multiple strategies in controlling acute lactic acidosis and bloat. The incidence of the two diseases may be controlled by strict dietary management. Gradual introduction of grain-based diets and the feeding of coarsely chopped roughage decrease the incidence of the two disease entities. Ionophores, which have been used to enhance feed conversion and growth rate in cattle, have been shown to inhibit the growth of lactic acid bacteria in the rumen. Other methods of controlling lactic acid bacteria in the ruminal environment (dietary supplementation of long-chain fatty acids, induction of passive and active immune responses to the bacteria, and the use of lytic bacteriophages) have also been investigated. It is anticipated that through continued in-depth ecological analysis of S. bovis the characteristics responsible for human and animal pathogenesis would be sufficiently identified to a point where more effective control strategies for the control of this bacteria can be developed.

  15. A study of ecological sanitation as an integrated urban water supply system: case study of sustainable strategy for Kuching City, Sarawak, Malaysia.

    Science.gov (United States)

    Seng, Darrien Mah Yau; Putuhena, Frederik Josep; Said, Salim; Ling, Law Puong

    2009-03-01

    A city consumes a large amount of water. Urban planning and development are becoming more compelling due to the fact of growing competition for water, which has lead to an increasing and conflicting demand. As such, investments in water supply, sanitation and water resources management is a strong potential for a solid return. A pilot project of greywater ecological treatment has been established in Kuching city since 2003. Such a treatment facility opens up an opportunity of wastewater reclamation for reuse as secondary sources of water for non-consumptive purposes. This paper aims to explore the potential of the intended purposes in the newly developed ecological treatment project. By utilizing the Wallingford Software model, InfoWorks WS (Water Supply) is employed to carry out a hydraulic modeling of a hypothetical greywater recycling system as an integrated part of the Kuching urban water supply, where the greywater is treated, recycled and reused in the domestic environment. The modeling efforts have shown water savings of about 40% from the investigated system reinstating that the system presents an alternative water source worth exploring in an urban environment.

  16. Bacterial computing with engineered populations.

    Science.gov (United States)

    Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

    2015-07-28

    We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  17. Ecological concepts

    International Nuclear Information System (INIS)

    1986-01-01

    This volume contains three critical contributions on the application of modern technology from the ethical point of view. The peaceful use of nuclear power is rejected as a technical error, which is overwhelming humanity. Ethical bases of a preventive technological policy and ecological aims are developed for the 21st century, in economy, technology, politics, and consciousness. (HSCH) [de

  18. Information Ecology

    DEFF Research Database (Denmark)

    Christiansen, Ellen Tove

    2006-01-01

    in the 1960ties, and chosen here because it integrates cultural and psychological trajectories in a theory of living settings. The pedagogical-didactical paradigm comprises three distinct information ecologies, named after their intended outcome: the problem-setting, the exploration-setting, and the fit...

  19. Political ecology

    International Nuclear Information System (INIS)

    Strohm, H.

    1979-01-01

    Using facts and examples, this didactically structures textbook gives an insight into the extent and consequences of the damage to the environment, with the subjects - fundamentals of ecology; - population and food problems; - the energy problem; - economic growth; scarcity of resources, recycling; - ground, water, and air pollution, - city and traffic problems; - work protection and medical care; - political alternatives and 'soft technologies'. The analysis of the political and economic reasons is combined with social and technical alternatives from which demands to be made and measures to be taken can be derived for individuals, citizens' interest groups, political groups and trade unions. Teaching models intend to help teachers to work on specific problems of ecology. (orig.) [de

  20. Wasteland ecologies

    DEFF Research Database (Denmark)

    Hoag, Colin Brewster; Bertoni, Filippo; Bubandt, Nils Ole

    2018-01-01

    landscapes, this article argues, are the result of unheralded multispecies collaboration that can be traced empirically by attending ethnographically to multispecies forms of “gain-making,” the ways in which humans and other species leverage difference to find economic and ecological opportunity....... in the 1970s, when prevailing perceptions were that the entire mining area was a polluted wasteland, the AFLD Fasterholt waste and recycling plant has since changed in response to new EU waste management regulations, as well as the unexpected proliferation of non-human life in the area. Based on field...... research at this site—an Anthropocene landscape in the heartland of an EU-configured welfare state — this article is a contribution to the multispecies ethnography and political ecology of wastelands. We argue that “waste” is a co-species, biopolitical happening — a complex symbolic, political, biological...

  1. Marine ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

  2. Terrestrial ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems

  3. Trade-offs between seed and leaf size (seed-phytomer-leaf theory): functional glue linking regenerative with life history strategies … and taxonomy with ecology?

    Science.gov (United States)

    Hodgson, John G; Santini, Bianca A; Montserrat Marti, Gabriel; Royo Pla, Ferran; Jones, Glynis; Bogaard, Amy; Charles, Mike; Font, Xavier; Ater, Mohammed; Taleb, Abdelkader; Poschlod, Peter; Hmimsa, Younes; Palmer, Carol; Wilson, Peter J; Band, Stuart R; Styring, Amy; Diffey, Charlotte; Green, Laura; Nitsch, Erika; Stroud, Elizabeth; Romo-Díez, Angel; de Torres Espuny, Lluis; Warham, Gemma

    2017-11-10

    While the 'worldwide leaf economics spectrum' (Wright IJ, Reich PB, Westoby M, et al. 2004. The worldwide leaf economics spectrum. Nature : 821-827) defines mineral nutrient relationships in plants, no unifying functional consensus links size attributes. Here, the focus is upon leaf size, a much-studied plant trait that scales positively with habitat quality and components of plant size. The objective is to show that this wide range of relationships is explicable in terms of a seed-phytomer-leaf (SPL) theoretical model defining leaf size in terms of trade-offs involving the size, growth rate and number of the building blocks (phytomers) of which the young shoot is constructed. Functional data for 2400+ species and English and Spanish vegetation surveys were used to explore interrelationships between leaf area, leaf width, canopy height, seed mass and leaf dry matter content (LDMC). Leaf area was a consistent function of canopy height, LDMC and seed mass. Additionally, size traits are partially uncoupled. First, broad laminas help confer competitive exclusion while morphologically large leaves can, through dissection, be functionally small. Secondly, leaf size scales positively with plant size but many of the largest-leaved species are of medium height with basally supported leaves. Thirdly, photosynthetic stems may represent a functionally viable alternative to 'small seeds + large leaves' in disturbed, fertile habitats and 'large seeds + small leaves' in infertile ones. Although key elements defining the juvenile growth phase remain unmeasured, our results broadly support SPL theory in that phytometer and leaf size are a product of the size of the initial shoot meristem (≅ seed mass) and the duration and quality of juvenile growth. These allometrically constrained traits combine to confer ecological specialization on individual species. Equally, they appear conservatively expressed within major taxa. Thus, 'evolutionary canalization' sensu Stebbins (Stebbins GL

  4. Towards Integrating Political Ecology into Resilience-Based Management

    OpenAIRE

    Amy Quandt

    2016-01-01

    One of the biggest challenges faced today is how to sustainably manage social-ecological systems for both ecological conservation and human wellbeing. This paper explores two approaches to understanding such systems: resilience thinking and political ecology. Resilience thinking is a framework that emerged over the last 40 years as a management strategy for social-ecological systems, and a resilient social-ecological system is capable of absorbing disturbances and still retaining its basic fu...

  5. Fuel poverty is facing a data challenge - Which strategies to struggle against fuel poverty? Propositions for an ecologic and social transition policy

    International Nuclear Information System (INIS)

    Erard, Timothee; Chancel, Lucas; Saujot, Mathieu

    2015-01-01

    The authors address three main questions: how are structured the network of actors and the tools for the struggle against fuel poverty, what are the specific data challenges faced by the actors and the possible responses, and which lessons can be learned for the governance of energy transition in its whole. After a presentation of the context of fuel poverty (analysis of tools for the struggle against fuel poverty, the use of social-energetic data), this study, based on about forty interviews of various actors and on a workshop, proposes an analysis framework which distinguishes six steps in the definition and implementation of policies of struggle against fuel poverty. After a description of the current status and an identification of required improvements for each step, the authors propose a set of recommendations, draw lessons for urban policies aimed at an ecologic transformation and a modernisation of the social protection system in terms of level of intervention, scope of actions, and ownership and access to data bases. These recommendations more particularly address the definition of fuel poverty, its diagnosis at the national and at the territorial level, a better identification of concerned households, and an assessment of existing arrangements

  6. Exploring bacterial lignin degradation.

    Science.gov (United States)

    Brown, Margaret E; Chang, Michelle C Y

    2014-04-01

    Plant biomass represents a renewable carbon feedstock that could potentially be used to replace a significant level of petroleum-derived chemicals. One major challenge in its utilization is that the majority of this carbon is trapped in the recalcitrant structural polymers of the plant cell wall. Deconstruction of lignin is a key step in the processing of biomass to useful monomers but remains challenging. Microbial systems can provide molecular information on lignin depolymerization as they have evolved to break lignin down using metalloenzyme-dependent radical pathways. Both fungi and bacteria have been observed to metabolize lignin; however, their differential reactivity with this substrate indicates that they may utilize different chemical strategies for its breakdown. This review will discuss recent advances in studying bacterial lignin degradation as an approach to exploring greater diversity in the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Intracellular Biosynthesis of Fluorescent CdSe Quantum Dots in Bacillus subtilis: A Strategy to Construct Signaling Bacterial Probes for Visually Detecting Interaction Between Bacillus subtilis and Staphylococcus aureus.

    Science.gov (United States)

    Yan, Zheng-Yu; Ai, Xiao-Xia; Su, Yi-Long; Liu, Xin-Ying; Shan, Xiao-Hui; Wu, Sheng-Mei

    2016-02-01

    In this work, fluorescent Bacillus subtilis (B. subtilis) cells were developed as probes for imaging applications and to explore behaviorial interaction between B. subtilis and Staphylococcus aureus (S. aureus). A novel biological strategy of coupling intracellular biochemical reactions for controllable biosynthesis of CdSe quantum dots by living B. subtilis cells was demonstrated, through which highly luminant and photostable fluorescent B. subtilis cells were achieved with good uniformity. With the help of the obtained fluorescent B. subtilis cells probes, S. aureus cells responded to co-cultured B. subtilis and to aggregate. The degree of aggregation was calculated and nonlinearly fitted to a polynomial model. Systematic investigations of their interactions implied that B. subtilis cells inhibit the growth of neighboring S. aureus cells, and this inhibition was affected by both the growth stage and the amount of surrounding B. subtilis cells. Compared to traditional methods of studying bacterial interaction between two species, such as solid culture medium colony observation and imaging mass spectrometry detection, the procedures were more simple, vivid, and photostable due to the efficient fluorescence intralabeling with less influence on the cells' surface, which might provide a new paradigm for future visualization of microbial behavior.

  8. Plasmids foster diversification and adaptation of bacterial populations in soil.

    Science.gov (United States)

    Heuer, Holger; Smalla, Kornelia

    2012-11-01

    It is increasingly being recognized that the transfer of conjugative plasmids across species boundaries plays a vital role in the adaptability of bacterial populations in soil. There are specific driving forces and constraints of plasmid transfer within bacterial communities in soils. Plasmid-mediated genetic variation allows bacteria to respond rapidly with adaptive responses to challenges such as irregular antibiotic or metal concentrations, or opportunities such as the utilization of xenobiotic compounds. Cultivation-independent detection and capture of plasmids from soil bacteria, and complete sequencing have provided new insights into the role and ecology of plasmids. Broad host range plasmids such as those belonging to IncP-1 transfer a wealth of accessory functions which are carried by similar plasmid backbones. Plasmids with a narrower host range can be more specifically adapted to particular species and often transfer genes which complement chromosomally encoded functions. Plasmids seem to be an ancient and successful strategy to ensure survival of a soil population in spatial and temporal heterogeneous conditions with various environmental stresses or opportunities that occur irregularly or as a novel challenge in soil. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  9. ECOLOGICAL ECONOMICS VS ECONOMIC(AL ECOLOGY

    Directory of Open Access Journals (Sweden)

    G. Kharlamova

    2015-10-01

    Full Text Available Currently world faces the dilemma – ecological economy or economic(al ecology. The researchers produce hundreds of surveys on the topic. However the analyses of recent most cited simulations had shown the diversity of results. Thus, for some states the Kuznets environmental curve has place, for others – no. Same could be said about different years for the same state. It provokes the necessity of drawing new group analyses to reveal the tendencies and relationships between economic and environmental factors. Most flexible and mirror factor of environmental sustainability is the volume of CO2 emissions. The econometric analysis was used for detecting the economic impact on this indicator at the global level and in the spectra of group of states depending on their income. The hypothesis of the existence of environmental Kuznets curve for the analysed data is rejected. Real GDP per capita impact on carbon dioxide emissions is considered only at the global level. The impact of openness of the economy is weak. Rejection happened also to the hypothesis that for the developed countries there is a reverse dependence between the environmental pollution and economic openness. Indicator “energy consumption per capita” impacts on greenhouse gas emissions only in countries with high income. Whereby it should be noted that the more developed a country is, the more elastic is this influence. These results have a potential usage for environmental policy regulation and climate strategy.

  10. Graphic Ecologies

    Directory of Open Access Journals (Sweden)

    Brook Weld Muller

    2014-12-01

    Full Text Available This essay describes strategic approaches to graphic representation associated with critical environmental engagement and that build from the idea of works of architecture as stitches in the ecological fabric of the city. It focuses on the building up of partial or fragmented graphics in order to describe inclusive, open-ended possibilities for making architecture that marry rich experience and responsive performance. An aphoristic approach to crafting drawings involves complex layering, conscious absence and the embracing of tension. A self-critical attitude toward the generation of imagery characterized by the notion of ‘loose precision’ may lead to more transformative and environmentally responsive architectures.

  11. Ecological carbon sequestration via wood harvest and storage (WHS): Can it be a viable climate mitigation and adaptation strategy for the Amazon?

    Science.gov (United States)

    Zeng, N.

    2015-12-01

    A carbon sequestration strategy is proposed in which forests are sustainably managed to optimal carbon productivity, and a fraction of the wood is selectively harvested and stored to prevent decomposition under anaerobic, dry or cold conditions. Because a large flux of CO2 is constantly assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. The live trees serve as a 'carbon scrubber' or 'carbon remover' that provides continuous sequestration (negative emissions). The stored wood is a semi-permanent carbon sink, but also serves as a 'biomass/bioenergy reserve' that could be utilized in the future. We discuss the particular relevance of this strategy to the Amazon which is under the double threat of climate change and deforestation. As an alternative to REDD, we propose mixed-use of peripheral Amazon basin while keeping the core of the Amazon intact. We argue that this may be a more practical solution in light of the likely climate change impact and human activities.

  12. HOLOCENE ECOLOGICAL TRAJECTORIES IN LAKE AND WETLAND SYSTEMS (AUVERGNE, FRANCE: A PALAEOENVIRONMENTAL CONTRIBUTION FOR A BETTER ASSESSMENT OF ECOSYSTEM AND LAND USE ‘S VIABILITY IN MANAGEMENT STRATEGIES.

    Directory of Open Access Journals (Sweden)

    Y. Miras

    2013-04-01

    Full Text Available Multi-proxy palaeoenvironmental studies are very important for the development of sustainable management strategies for ecosystems and modern landscapes. Analysing the relationship between societies, climate and environments through time, these studies contribute to define adequate policies and strategies for socio-environmental management, protection and legacy. Two complementary case studies– Aydat lake and Espinasse fen - from the south of the Chaîne des Puys (Auvergne, Massif Central, France are presented. The analysis of these sedimentological records (both lacustrine and peat follows a multi-proxy approach combining abiotic and biotic palaeoindicators (density, magnetic susceptibility, X-Ray Fluorescence spectrometry, Rock-Eval, pollen, non-pollen palynomorphs, molecular biomarkers. Aydat lake and Espinasse fen analyses were performed following a high spatio-temporal resolution. Results underline that long-term models of detrital input and eutrophication correspond to complex patterns with early and recurrent phases of human-induced ecological disturbances. They also evidence the existence of diversified long-term land use systems (deforestation, grazing, agriculture, hemp culture and retting that provide fresh insights into the understanding of present-day mountain environments. This history between diversified human activities and hydrosystems responses must be taken into account for the construction of accurate retrospective and prospective model simulations of hydrosystem functioning.

  13. Principles for ecologically based invasive plant management

    Science.gov (United States)

    Jeremy J. James; Brenda S. Smith; Edward A. Vasquez; Roger L. Sheley

    2010-01-01

    Land managers have long identified a critical need for a practical and effective framework for designing restoration strategies, especially where invasive plants dominate. A holistic, ecologically based, invasive plant management (EBIPM) framework that integrates ecosystem health assessment, knowledge of ecological processes, and adaptive management into a successional...

  14. Bacterial pathogen manipulation of host membrane trafficking.

    Science.gov (United States)

    Asrat, Seblewongel; de Jesús, Dennise A; Hempstead, Andrew D; Ramabhadran, Vinay; Isberg, Ralph R

    2014-01-01

    Pathogens use a vast number of strategies to alter host membrane dynamics. Targeting the host membrane machinery is important for the survival and pathogenesis of several extracellular, vacuolar, and cytosolic bacteria. Membrane manipulation promotes bacterial replication while suppressing host responses, allowing the bacterium to thrive in a hostile environment. This review provides a comprehensive summary of various strategies used by both extracellular and intracellular bacteria to hijack host membrane trafficking machinery. We start with mechanisms used by bacteria to alter the plasma membrane, delve into the hijacking of various vesicle trafficking pathways, and conclude by summarizing bacterial adaptation to host immune responses. Understanding bacterial manipulation of host membrane trafficking provides insights into bacterial pathogenesis and uncovers the molecular mechanisms behind various processes within a eukaryotic cell.

  15. European ecological networks and greenways

    NARCIS (Netherlands)

    Jongman, R.H.G.; Külvik, M.; Kristiansen, I.

    2004-01-01

    In the context of European integration, networks are becoming increasingly important in both social and ecological sense. Since the beginning of the 1990s, societal and scientific exchanges are being restructured as the conceptual approaches towards new nature conservation strategies have been

  16. Batch medication of intestinal infections in nursery pigs-A randomised clinical trial on the efficacy of treatment strategy, type of antibiotic and bacterial load on average daily weight gain.

    Science.gov (United States)

    Weber, Nicolai Rosager; Pedersen, Ken Steen; Hansen, Christian Fink; Denwood, Matthew; Hjulsager, Charlotte Kristiane; Nielsen, Jens Peter

    2017-02-01

    Previous research projects have demonstrated the need for better diagnostic tools to support decisions on medication strategies for infections caused by Escherichia coli F4 (F4) and F18 (F18), Lawsonia intracellularis (LI) and Brachyspira pilosicoli (PILO). This study was carried out as a randomised clinical trial in three Danish pig herds and included 1047 nursery pigs, distributed over 10 batches and 78 pens. The objectives of this study were: (1) to assess the effect of four 5-day treatment strategies (initiated at clinical outbreak of diarrhoea or at fixed time points 14, 21, or 28days after weaning) on average daily weight gain (ADG); (2) to compare the effect of treatment with doxycycline or tylosine on diarrhoea prevalence, pathogenic bacterial load, and ADG; (3) to evaluate PCR testing of faecal pen floor samples as a diagnostic tool for determining the optimal time of treatment. (1) The four treatment strategies had a significant overall effect on ADG (p=0.01). Pigs starting treatment 14days after weaning had a significantly higher ADG (42 g) compared to pigs treated on day 28 (p=0.01). (2) When measured 2days after treatment, doxycycline treatment resulted in fewer LI-positive pens (p=0.004), lower excretion levels of LI (p=0.013), and fewer pens with a high level of LI (p=0.031) compared to pens treated with tylosine. There was no significant difference in F4, F18 and PILO levels after treatment with the two antibiotic compounds. There was a significant difference (p=0.04) of mean diarrhoea prevalence on day 21 of the study between pens treated with tylosine (0.254, 95% CI: 0.184-0.324), and doxycycline (0.167, 95% CI: 0.124-0.210). The type of antibiotic compound was not found to have a significant effect on ADG (p=0.209). (3) Pigs starting treatment on day 14 in pens where F4, F18, LI or PILO were detected by qPCR on the pen floor had a statistically significant increase in ADG (66g) compared to pigs treated on day 14 in pens where no enteric pathogens

  17. Heme Synthesis and Acquisition in Bacterial Pathogens

    OpenAIRE

    Choby, Jacob E.; Skaar, Eric P.

    2016-01-01

    Bacterial pathogens require the iron-containing cofactor heme to cause disease. Heme is essential to the function of hemoproteins, which are involved in energy generation by the electron transport chain, detoxification of host immune effectors, and other processes. During infection, bacterial pathogens must synthesize heme or acquire heme from the host; however, host heme is sequestered in high-affinity hemoproteins. Pathogens have evolved elaborate strategies to acquire heme from host source...

  18. Media Ecology

    Directory of Open Access Journals (Sweden)

    Marina Ašković

    2015-05-01

    Full Text Available Does the trend in which electronic media are gradually becoming extension of human body have to move towards full enslavement of a human and his personality, or the same human will unpredictably, with the aid of his personal media literacy, exit the whirls of media and technological censorships? Personality crisis is closely related to the crisis of language no matter how contradicted to global ideology of transnational transhumanism it may seem. Considering the fact that recent media presentations of the world are based on commercialization of environmentalism, philosophical and aesthetic thought appears as an important subject of ecology. As media mediates, the scenery of civilized living increasingly becomes more appealing even though it derives from commercial and political background. Consequently, the future of humanity depends by large on the philosophy of media. Media have to truly ecologise returning the humanum to its essence making it into the extension of the natural world.

  19. Current Knowledge on Listeria monocytogenes Biofilms in Food-Related Environments: Incidence, Resistance to Biocides, Ecology and Biocontrol

    Directory of Open Access Journals (Sweden)

    Pedro Rodríguez-López

    2018-06-01

    Full Text Available Although many efforts have been made to control Listeria monocytogenes in the food industry, growing pervasiveness amongst the population over the last decades has made this bacterium considered to be one of the most hazardous foodborne pathogens. Its outstanding biocide tolerance capacity and ability to promiscuously associate with other bacterial species forming multispecies communities have permitted this microorganism to survive and persist within the industrial environment. This review is designed to give the reader an overall picture of the current state-of-the-art in L. monocytogenes sessile communities in terms of food safety and legislation, ecological aspects and biocontrol strategies.

  20. Ecological Ethics

    International Nuclear Information System (INIS)

    Oughton, Deborah

    2013-01-01

    Deborah Oughton started with a view of the work in progress by the ICRP TG 94 on ethics, from the historical context and the principles-based ethics in RP, to continue with an overview of the ethical theories and with the main area of elaboration which concerns the common values, to conclude with considerations about the implementation in different area such as biomedicine, nuclear safety and workers, ecological aspects, and environmental health and society. By reading again the ICRP and IAEA publications on the ethical aspects in the protection of environment from the effects of ionizing radiation, the presentation covers the various and different cultures within the history of environmental ethics, the perception of Nature and the theories of environmental ethics, in particular by focusing on anthropocentrism, biocentrism and ecocentrism, as philosophical worldwide views, and on conservation, biodiversity, sustainability, environmental justice and human dignity, as primary principles of environmental protection. The influence of western Christianity, with a view of man dominating over every creeping thing on earth, and of the non-western ideas, the human perception of Nature has been analyzed and discussed to conclude that, in reality then, the anthropocentrism, biocentrism and ecocentrism, as reflected in many cultures and religions, they all support the need to protect the environment and to recognise and preserve the diversity. Three challenges were then discussed in the presentation: the ecosystem approach and ecological economics, for example in the case of Fukushima by asking what is the economic cost of marine contamination; the ecosystem changes with attention to what harms, as in the case of the environment in the contaminated areas around Chernobyl; and the environmental consequences of remediation, which can be considered a source of controversy for environmental ethics and policy

  1. Ecological stability of landscape - ecological infrastructure - ecological management

    International Nuclear Information System (INIS)

    1992-01-01

    The Field Workshop 'Ecological Stability of Landscape - Ecological Infrastructure - Ecological Management' was held within a State Environmental Programme financed by the Federal Committee for the Environment. The objectives of the workshop were to present Czech and Slovak approaches to the ecological stability of the landscape by means of examples of some case studies in the field, and to exchange ideas, theoretical knowledge and practical experience on implementing the concept of ecological infrastructure in landscape management. Out of 19 papers contained in the proceedings, 3 items were inputted to the INIS system. (Z.S.)

  2. The microbial ecology of permafrost

    DEFF Research Database (Denmark)

    Jansson, Janet; Tas, Neslihan

    2014-01-01

    Permafrost constitutes a major portion of the terrestrial cryosphere of the Earth and is a unique ecological niche for cold-adapted microorganisms. There is a relatively high microbial diversity in permafrost, although there is some variation in community composition across different permafrost......-gas emissions. This Review describes new data on the microbial ecology of permafrost and provides a platform for understanding microbial life strategies in frozen soil as well as the impact of climate change on permafrost microorganisms and their functional roles....

  3. Minerals in soil select distinct bacterial communities in their microhabitats.

    Science.gov (United States)

    Carson, Jennifer K; Campbell, Louise; Rooney, Deirdre; Clipson, Nicholas; Gleeson, Deirdre B

    2009-03-01

    We tested the hypothesis that different minerals in soil select distinct bacterial communities in their microhabitats. Mica (M), basalt (B) and rock phosphate (RP) were incubated separately in soil planted with Trifolium subterraneum, Lolium rigidum or left unplanted. After 70 days, the mineral and soil fractions were separated by sieving. Automated ribosomal intergenic spacer analysis was used to determine whether the bacterial community structure was affected by the mineral, fraction and plant treatments. Principal coordinate plots showed clustering of bacterial communities from different fraction and mineral treatments, but not from different plant treatments. Permutational multivariate anova (permanova) showed that the microhabitats of M, B and RP selected bacterial communities different from each other in unplanted and L. rigidum, and in T. subterraneum, bacterial communities from M and B differed (Ppermanova also showed that each mineral fraction selected bacterial communities different from the surrounding soil fraction (P<0.05). This study shows that the structure of bacterial communities in soil is influenced by the mineral substrates in their microhabitat and that minerals in soil play a greater role in bacterial ecology than simply providing an inert matrix for bacterial growth. This study suggests that mineral heterogeneity in soil contributes to the spatial variation in bacterial communities.

  4. Indigenous Ecological Knowledge and Modern Western Ecological ...

    African Journals Online (AJOL)

    Indigenous knowledge is often dismissed as 'traditional and outdated', and hence irrelevant to modern ecological assessment. This theoretical paper critically examines the arguments advanced to elevate modern western ecological knowledge over indigenous ecological knowledge, as well as the sources and uses of ...

  5. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection

    DEFF Research Database (Denmark)

    Ernstsen, Christina Lundgaard; Login, Frédéric H.; Jensen, Helene Halkjær

    2017-01-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacteria...

  6. [Dynamic changes of ecological footprint and ecological capacity in Fujian Province].

    Science.gov (United States)

    Weng, Boqi; Wang, Yixiang; Huang, Yibin; Ying, Zhaoyang; Huang, Qinlou

    2006-11-01

    The analysis on the dynamic changes of ecological footprint and ecological capacity in Fujian Province showed that in 1999-2003, the ecological footprint per capita in the Province increased from 1.428 hm2 to 1.658 hm2, while the ecological capacity per capita decreased from 0.683 hm2 to 0.607 hm2, with an increased ecological deficit year after year. The contradiction between the ecological footprint and ecological capacity pricked up gradually, and the ecological environment was at risk. There existed a severe imbalance in the supply and demand of ecological footprint per capita. The main body of the demands was grassland and fossil fuel, accouting for 55.74% - 63.43% of the total, while their supply only occupied 0.77% - 0.82% and next to nothing of the ecological capacity per capita, respectively. As a whole, the ecological footprint per ten thousand yuan GDP declined in the five years, indicating that the resources use efficiency in the Province was improved gradually. Based on the analysis of the present situation of the economic development and resources distribution in the Province, the strategies on reducing ecological deficit were put forward.

  7. Both species sorting and neutral processes drive assembly of bacterial communities in aquatic microcosms

    NARCIS (Netherlands)

    Lee, Jack E.; Buckley, Hannah L.; Etienne, Rampal S.; Lear, Gavin

    2013-01-01

    A focus of ecology is to determine drivers of community assembly. Here, we investigate effects of immigration and species sorting (environmental selection) on structuring aquatic bacterial communities in both colonised and previously uncolonised environments. We used nonsterilised and presterilised

  8. Distributions of Bacterial Generalists among the Guts of Birds, Fish, and Mammals - abstract

    Science.gov (United States)

    Complex distributions of bacterial taxa within diverse animal microbiomes have inspired ecological and biogeographical approaches to revealing the functions of taxa that may be most important for host health. Of particular interest are bacteria that find many diverse habitats sui...

  9. Ecology and genomics of Bacillus subtilis.

    Science.gov (United States)

    Earl, Ashlee M; Losick, Richard; Kolter, Roberto

    2008-06-01

    Bacillus subtilis is a remarkably diverse bacterial species that is capable of growth within many environments. Recent microarray-based comparative genomic analyses have revealed that members of this species also exhibit considerable genomic diversity. The identification of strain-specific genes might explain how B. subtilis has become so broadly adapted. The goal of identifying ecologically adaptive genes could soon be realized with the imminent release of several new B. subtilis genome sequences. As we embark upon this exciting new era of B. subtilis comparative genomics we review what is currently known about the ecology and evolution of this species.

  10. Bacterial ecology of tilapia fresh fillets and some factors that can influence their microbial quality Ecologia bacteriana de filés frescos de tilápia e de pontos capazes de influenciar a sua qualidade microbiológica

    Directory of Open Access Journals (Sweden)

    Cleube Andrade Boari

    2008-12-01

    Full Text Available The purpose of research was to investigate the bacterial ecology of tilapia (Oreochromis niloticus fresh fillets and some factors that can influence its microbial quality. Samples of fish cultivation water (n = 20, tilapia tegument and gut (n = 20 and fresh fillets (n = 20 were collected in an experimental tilapia aquaculture located in the city of Lavras, Minas Gerais, Brazil. Staphylococcus spp., Aeromonas spp., Enterococcus spp. and Enterobacteriaceae were quantified using selective plating. For the enumeration of Pseudomonas spp., the most probable number technique (MPN was utilized. Bacterial colonies (n = 198 were identified by Gram strain and biochemical tests. Aeromonas spp., Pseudomonas spp., Enterococcus spp. and Enterobacteriaceae were found in the cultivation water (water from a fishpond cultivation, tegument, gut, and fresh fillets. Staphylococcus spp. was not isolated in the cultivation water. Salmonella spp. was not detected. The count variable of 10 to 10³ CFU or MPN.(g or mL-1. Associated to freshwater tilapia fillet processing, there is a large variety of microorganisms related to foodborne illnesses and fish products deterioration.A presente pesquisa foi conduzida com o objetivo de se investigar a ecologia microbiana de filés frescos de tilápia (Oreochromis niloticus e de pontos capazes de influenciar em sua qualidade microbiológica. Para sua condução, amostras de água de cultivo (n = 20, tegumento e trato gastrintestinal (n = 20 e filés frescos (n = 20 foram coletados em um sistema de produção aqüícola de água doce localizado em Lavras, Minas Gerais, Brasil. Staphylococcus spp., Aeromonas spp., Enterococcus spp., Enterobacteriaceae foram quantificados através de plaqueamento seletivo. Pseudomonas spp. foi enumerada através da técnica do número mais provável. Colônias (n = 198 foram identificadas por coloração de Gram e testes bioquímicos. Aeromonas spp., Pseudomonas spp., Enterococcus spp. e

  11. Evaluation of the bacterial diversity of pressure ulcers using bTEFAP pyrosequencing.

    Science.gov (United States)

    Smith, Drake M; Snow, David E; Rees, Eric; Zischkau, Ann M; Hanson, J Delton; Wolcott, Randall D; Sun, Yan; White, Jennifer; Kumar, Shashi; Dowd, Scot E

    2010-09-21

    Decubitus ulcers, also known as bedsores or pressure ulcers, affect millions of hospitalized patients each year. The microflora of chronic wounds such as ulcers most commonly exist in the biofilm phenotype and have been known to significantly impair normal healing trajectories. Bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP), a universal bacterial identification method, was used to identify bacterial populations in 49 decubitus ulcers. Diversity estimators were utilized and wound community compositions analyzed in relation to metadata such as Age, race, gender, and comorbidities. Decubitus ulcers are shown to be polymicrobial in nature with no single bacterium exclusively colonizing the wounds. The microbial community among such ulcers is highly variable. While there are between 3 and 10 primary populations in each wound there can be hundreds of different species present many of which are in trace amounts. There is no clearly significant differences in the microbial ecology of decubitus ulcer in relation to metadata except when considering diabetes. The microbial populations and composition in the decubitus ulcers of diabetics may be significantly different from the communities in non-diabetics. Based upon the continued elucidation of chronic wound bioburdens as polymicrobial infections, it is recommended that, in addition to traditional biofilm-based wound care strategies, an antimicrobial/antibiofilm treatment program can be tailored to each patient's respective wound microflora.

  12. Evaluation of the bacterial diversity of Pressure ulcers using bTEFAP pyrosequencing

    Directory of Open Access Journals (Sweden)

    Wolcott Randall D

    2010-09-01

    Full Text Available Abstract Background Decubitus ulcers, also known as bedsores or pressure ulcers, affect millions of hospitalized patients each year. The microflora of chronic wounds such as ulcers most commonly exist in the biofilm phenotype and have been known to significantly impair normal healing trajectories. Methods Bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP, a universal bacterial identification method, was used to identify bacterial populations in 49 decubitus ulcers. Diversity estimators were utilized and wound community compositions analyzed in relation to metadata such as Age, race, gender, and comorbidities. Results Decubitus ulcers are shown to be polymicrobial in nature with no single bacterium exclusively colonizing the wounds. The microbial community among such ulcers is highly variable. While there are between 3 and 10 primary populations in each wound there can be hundreds of different species present many of which are in trace amounts. There is no clearly significant differences in the microbial ecology of decubitus ulcer in relation to metadata except when considering diabetes. The microbial populations and composition in the decubitus ulcers of diabetics may be significantly different from the communities in non-diabetics. Conclusions Based upon the continued elucidation of chronic wound bioburdens as polymicrobial infections, it is recommended that, in addition to traditional biofilm-based wound care strategies, an antimicrobial/antibiofilm treatment program can be tailored to each patient's respective wound microflora.

  13. Bacterial lung abscess

    International Nuclear Information System (INIS)

    Groskin, S.A.; Panicek, D.M.; Ewing, D.K.; Rivera, F.; Math, K.; Teixeira, J.; Heitzman, E.R.

    1987-01-01

    A retrospective review of patients with bacterial lung abscess was carried out. Demographic, clinical, and radiographical features of this patient group are compared with similar data from patients with empyema and/or cavitated lung carcinoma; differential diagnostic points are stressed. The entity of radiographically occult lung abscess is discussed. Complications associated with bacterial lung abscess are discussed. Current therapeutic options and treatment philosophy for patients with bacterial lung abscess are noted

  14. Urban Ecology and Transformation of Technical Infrastructure

    DEFF Research Database (Denmark)

    Nielsen, Susanne Balslev

    1999-01-01

    -down strategies instead of seeing such strategies as incompatible. Today´s planning practice and the momentum of the established systems require new forums for stratgic debates if urban ecology is to be included in future network management. A methodolgy is presented for structuring a debate on future sustainable...

  15. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  16. Heme Synthesis and Acquisition in Bacterial Pathogens.

    Science.gov (United States)

    Choby, Jacob E; Skaar, Eric P

    2016-08-28

    Bacterial pathogens require the iron-containing cofactor heme to cause disease. Heme is essential to the function of hemoproteins, which are involved in energy generation by the electron transport chain, detoxification of host immune effectors, and other processes. During infection, bacterial pathogens must synthesize heme or acquire heme from the host; however, host heme is sequestered in high-affinity hemoproteins. Pathogens have evolved elaborate strategies to acquire heme from host sources, particularly hemoglobin, and both heme acquisition and synthesis are important for pathogenesis. Paradoxically, excess heme is toxic to bacteria and pathogens must rely on heme detoxification strategies. Heme is a key nutrient in the struggle for survival between host and pathogen, and its study has offered significant insight into the molecular mechanisms of bacterial pathogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Application of Chemical Genomics to Plant-Bacteria Communication: A High-Throughput System to Identify Novel Molecules Modulating the Induction of Bacterial Virulence Genes by Plant Signals.

    Science.gov (United States)

    Vandelle, Elodie; Puttilli, Maria Rita; Chini, Andrea; Devescovi, Giulia; Venturi, Vittorio; Polverari, Annalisa

    2017-01-01

    The life cycle of bacterial phytopathogens consists of a benign epiphytic phase, during which the bacteria grow in the soil or on the plant surface, and a virulent endophytic phase involving the penetration of host defenses and the colonization of plant tissues. Innovative strategies are urgently required to integrate copper treatments that control the epiphytic phase with complementary tools that control the virulent endophytic phase, thus reducing the quantity of chemicals applied to economically and ecologically acceptable levels. Such strategies include targeted treatments that weaken bacterial pathogens, particularly those inhibiting early infection steps rather than tackling established infections. This chapter describes a reporter gene-based chemical genomic high-throughput screen for the induction of bacterial virulence by plant molecules. Specifically, we describe a chemical genomic screening method to identify agonist and antagonist molecules for the induction of targeted bacterial virulence genes by plant extracts, focusing on the experimental controls required to avoid false positives and thus ensuring the results are reliable and reproducible.

  18. Socio-Ecological Innovation

    DEFF Research Database (Denmark)

    Edgeman, Rick; Eskildsen, Jacob Kjær

    Socio‐Ecological Innovation or SEI is innovation resulting from strategic integration of sustainable innovation and innovation for sustainability. In particular SEI is regarded as critical to organizations intent on progressing toward Sustainable Enterprise Excellence (SEE) and, indeed, progressing......, how developed or mature it is, and how future SEI strategy and results can be improved. As an aid to these efforts, non‐prescriptive approaches to SEI are discussed, maturity scale assessment for SEI is developed and discussed, and a simple assessment report that combines graphic and narrative...... feedback is presented. The assessment report is referred to as a SEI News Report and is intended not only to provide feedback to the organization concerning its present SEI performance, but also to deliver significant foresight that will inform future SEI efforts, strengthening the likelihood...

  19. Tales from the tomb: the microbial ecology of exposed rock surfaces.

    Science.gov (United States)

    Brewer, Tess E; Fierer, Noah

    2018-03-01

    Although a broad diversity of eukaryotic and bacterial taxa reside on rock surfaces where they can influence the weathering of rocks and minerals, these communities and their contributions to mineral weathering remain poorly resolved. To build a more comprehensive understanding of the diversity, ecology and potential functional attributes of microbial communities living on rock, we sampled 149 tombstones across three continents and analysed their bacterial and eukaryotic communities via marker gene and shotgun metagenomic sequencing. We found that geographic location and climate were important factors structuring the composition of these communities. Moreover, the tombstone-associated microbial communities varied as a function of rock type, with granite and limestone tombstones from the same cemeteries harbouring taxonomically distinct microbial communities. The granite and limestone-associated communities also had distinct functional attributes, with granite-associated bacteria having more genes linked to acid tolerance and chemotaxis, while bacteria on limestone were more likely to be lichen associated and have genes involved in photosynthesis and radiation resistance. Together these results indicate that rock-dwelling microbes exhibit adaptations to survive the stresses of the rock surface, differ based on location, climate and rock type, and seem pre-disposed to different ecological strategies (symbiotic versus free-living lifestyles) depending on the rock type. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  20. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    . As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  1. Towards improving the ethics of ecological research.

    Science.gov (United States)

    Crozier, G K D; Schulte-Hostedde, Albrecht I

    2015-06-01

    We argue that the ecological research community should develop a plan for improving the ethical consistency and moral robustness of the field. We propose a particular ethics strategy--specifically, an ongoing process of collective ethical reflection that the community of ecological researchers, with the cooperation of applied ethicists and philosophers of biology, can use to address the needs we identify. We suggest a particular set of conceptual (in the form of six core values--freedom, fairness, well being, replacement, reduction, and refinement) and analytic (in the forms of decision theoretic software, 1000Minds) tools that, we argue, collectively have the resources to provide an empirically grounded and conceptually complete foundation for an ethics strategy for ecological research. We illustrate our argument with information gathered from a survey of ecologists conducted at the 2013 meeting of the Canadian Society of Ecology and Evolution.

  2. Ecological periodic tables for bentkhic macrofauna and nekton usage in estuarine habitats

    Science.gov (United States)

    In his presidential address to the British Ecological Society, T.R.E. Southwood (1977: Habitat, the templet for ecological strategies? Journal of Animal Ecology 46: 337-365; http://www.jstor.org/stable/3817) compared the situation in ecology to that in chemistry before the devel...

  3. The relation between oral Candida load and bacterial microbiome profiles in Dutch older adults

    NARCIS (Netherlands)

    Kraneveld, E.A.; Buijs, M.J.; Bonder, M.J.; Visser, M.; Keijser, B.J.F.; Crielaard, W.; Zaura, E.

    2012-01-01

    Currently there are no evidence-based ecological measures for prevention of overgrowth and subsequent infection by fungi in the oral cavity. The aim of this study was to increase our knowledge on fungal-bacterial ecological interactions. Salivary Candida abundance of 82 Dutch adults aged 58-80 years

  4. The relation between oral candida load and bacterial microbiome profiles in dutch older adults

    NARCIS (Netherlands)

    Kraneveld, E.A.; Buijs, M.J.; Bonder, M.J.; Visser, M.; Keijser, B.J.F.; Crielaard, W.; Zaura, E.

    2012-01-01

    Currently there are no evidence-based ecological measures for prevention of overgrowth and subsequent infection by fungi in the oral cavity. The aim of this study was to increase our knowledge on fungal-bacterial ecological interactions. Salivary Candida abundance of 82 Dutch adults aged 58-80 years

  5. The Relation between Oral Candida Load and Bacterial Microbiome Profiles in Dutch Older Adults.

    NARCIS (Netherlands)

    Kraneveld, E.A.; Buijs, M.J.; Bonder, M.J.; Visser, M.; Keijser, B.J.; Crielaard, W.; Zaura, E.

    2012-01-01

    Currently there are no evidence-based ecological measures for prevention of overgrowth and subsequent infection by fungi in the oral cavity. The aim of this study was to increase our knowledge on fungal-bacterial ecological interactions. Salivary Candida abundance of 82 Dutch adults aged 58-80 years

  6. Identifying Bacterial Immune Evasion Proteins Using Phage Display.

    Science.gov (United States)

    Fevre, Cindy; Scheepmaker, Lisette; Haas, Pieter-Jan

    2017-01-01

    Methods aimed at identification of immune evasion proteins are mainly rely on in silico prediction of sequence, structural homology to known evasion proteins or use a proteomics driven approach. Although proven successful these methods are limited by a low efficiency and or lack of functional identification. Here we describe a high-throughput genomic strategy to functionally identify bacterial immune evasion proteins using phage display technology. Genomic bacterial DNA is randomly fragmented and ligated into a phage display vector that is used to create a phage display library expressing bacterial secreted and membrane bound proteins. This library is used to select displayed bacterial secretome proteins that interact with host immune components.

  7. Bacterial contamination of platelet concentrates: pathogen detection and inactivation methods

    Directory of Open Access Journals (Sweden)

    Dana Védy

    2009-04-01

    Full Text Available Whereas the reduction of transfusion related viral transmission has been a priority during the last decade, bacterial infection transmitted by transfusion still remains associated to a high morbidity and mortality, and constitutes the most frequent infectious risk of transfusion. This problem especially concerns platelet concentrates because of their favorable bacterial growth conditions. This review gives an overview of platelet transfusion-related bacterial contamination as well as on the different strategies to reduce this problem by using either bacterial detection or inactivation methods.

  8. Ecological units: definitions and application.

    Science.gov (United States)

    Jax, Kurt

    2006-09-01

    Concepts of ecological units, such as population, community, and ecosystem, are at the basis of ecological theory and research and have increasingly become the focus of conservation strategies. Concepts of these units still suffer from inconsistencies and confusions over terminology. The different concepts are treated here together as a common "conceptual cluster," with similar ecological functions (roles) and similar problems in their definition and use. An analysis of the multitude of existing terms and concepts that have been developed for these units reveals that they differ with respect to at least four basic criteria: (i) the questions as to whether they are defined statistically or via a network of interactions; (ii) if their boundaries are drawn by topographical or process-related criteria; (iii) how high the required internal relationships are; and (iv) if they are perceived as "real" entities or abstractions by an observer The various definitions cannot be easily sorted into just a few types, but they can be characterized by several independent criteria. I argue that serious problems arise if the different possibilities of defining ecological units are not recognized and if the concepts are perceived as self-evident. The different concepts of ecological units should be defined and used in a philosophically informed manner I propose a dual approach to the use of ecological units. Generic meanings of the main concepts (especially population, community, and ecosystem) should be retained only as heuristically useful perspectives, while specific and "operational" definitions of the concepts as units should be developed, depending on specific purposes of their use. Some thoughts on the basic requirements for such definitions and the domains of their uses are briefly explained.

  9. Ecologies of Learning, Ecologies of Creativity

    DEFF Research Database (Denmark)

    Høyrup, Helene

    in the light of the new Danish school reform. How can different learning institutions contribute to a “joint” ecology of learning? What would the benefits be from this in terms of young people’s literacies? On what theoretical basis can such an ecology and co-creation take place? And what kind of didactics...

  10. Isolation of hydrocarbon utilizing bacteria from different ecological sources

    International Nuclear Information System (INIS)

    Iqbal, M.J.; Choudri, S.F.; Hameed, A.

    1991-01-01

    Among the various samples from different ecological sources oil contaminated soil samples and waste from sugar processing industry were found to have bacterial populations with ability of utilizing oil. In addition to oil, molasses base medium was also used to study the utilizing ability. Selection was made on the basis on the high gas production, decrease in pH, percentage of oil consumed and bacterial counts. Fermented scum and oil contaminated soil from Sehala (Islamabad) were found to contain microbes having maximum oil degrading ability. The bacterial isolates belong to the genera of Bacillus, Pseudomonas, Enterobacter and Escherichia. (author)

  11. Changes in bacterial diversity associated with bioremediation of used lubricating oil in tropical soils.

    Science.gov (United States)

    Meeboon, Naruemon; Leewis, Mary-Cathrine; Kaewsuwan, Sireewan; Maneerat, Suppasil; Leigh, Mary Beth

    2017-08-01

    Used lubricating oil (ULO) is a widespread contaminant, particularly throughout tropical regions, and may be a candidate for bioremediation. However, little is known about the biodegradation potential or basic microbial ecology of ULO-contaminated soils. This study aims to determine the effects of used ULO on bacterial community structure and diversity. Using a combination of culture-based (agar plate counts) and molecular techniques (16S rRNA gene sequencing and DGGE), we investigated changes in soil bacterial communities from three different ULO-contaminated soils collected from motorcycle mechanical workshops (soil A, B, and C). We further explored the relationship between bacterial community structure, physiochemical soil parameters, and ULO composition in three ULO-contaminated soils. Results indicated that the three investigated soils had different community structures, which may be a result of the different ULO characteristics and physiochemical soil parameters of each site. Soil C had the highest ULO concentration and also the greatest diversity and richness of bacteria, which may be a result of higher nutrient retention, organic matter and cation exchange capacity, as well as freshness of oil compared to the other soils. In soils A and B, Proteobacteria (esp. Gammaproteobacteria) dominated the bacterial community, and in soil C, Actinobacteria and Firmicutes dominated. The genus Enterobacter, a member of the class Gammaproteobacteria, is known to include ULO-degraders, and this genus was the only one found in all three soils, suggesting that it could play a key role in the in situ degradation of ULO-contaminated tropical Thai soils. This study provides insights into our understanding of soil microbial richness, diversity, composition, and structure in tropical ULO-contaminated soils, and may be useful for the development of strategies to improve bioremediation.

  12. Molecular mechanisms of action of bacterial exotoxins.

    Science.gov (United States)

    Balfanz, J; Rautenberg, P; Ullmann, U

    1996-07-01

    Toxins are one of the inventive strategies that bacteria have developed in order to survive. As virulence factors, they play a major role in the pathogenesis of infectious diseases. Recent discoveries have once more highlighted the effectiveness of these precisely adjusted bacterial weapons. Furthermore, toxins have become an invaluable tool in the investigation of fundamental cell processes, including regulation of cellular functions by various G proteins, cytoskeletal dynamics and neural transmission. In this review, the bacterial toxins are presented in a rational classification based on the molecular mechanisms of action.

  13. Taoism and Deep Ecology.

    Science.gov (United States)

    Sylvan, Richard; Bennett, David

    1988-01-01

    Contrasted are the philosophies of Deep Ecology and ancient Chinese. Discusses the cosmology, morality, lifestyle, views of power, politics, and environmental philosophies of each. Concludes that Deep Ecology could gain much from Taoism. (CW)

  14. Information Assurance Cyber Ecology

    National Research Council Canada - National Science Library

    Jorgensen, Jane

    2003-01-01

    .... The goals of the Cyber Ecology project were to: (1) enable and demonstrate the discovery of noel IA technologies for the detection and mitigation of damage due to cyber attack through the application of ecological models, (2...

  15. Forest Fire Ecology.

    Science.gov (United States)

    Zucca, Carol; And Others

    1995-01-01

    Presents a model that integrates high school science with the needs of the local scientific community. Describes how a high school ecology class conducted scientific research in fire ecology that benefited the students and a state park forest ecologist. (MKR)

  16. The enzymes of bacterial census and censorship.

    Science.gov (United States)

    Fast, Walter; Tipton, Peter A

    2012-01-01

    N-Acyl-L-homoserine lactones (AHLs) are a major class of quorum-sensing signals used by Gram-negative bacteria to regulate gene expression in a population-dependent manner, thereby enabling group behavior. Enzymes capable of generating and catabolizing AHL signals are of significant interest for the study of microbial ecology and quorum-sensing pathways, for understanding the systems that bacteria have evolved to interact with small-molecule signals, and for their possible use in therapeutic and industrial applications. The recent structural and functional studies reviewed here provide a detailed insight into the chemistry and enzymology of bacterial communication. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Quantification of ecological debt

    International Nuclear Information System (INIS)

    Martinez Alier, Joan

    2005-01-01

    The discussion about ecological debt is important keeping in mind historical foreign trade, where natural resources exploitation and primary production exported didn't assessment the ecological damage or the environmental values of the interchange. This essay shows the debate of ecological debt on greenhouse emission, enterprise environmental debit, unequal international trade, toxic waste export, and b io piracy ; in order to present the necessity of a new ecological and equitable world economy

  18. ENVIRONMENTAL PHILOSOPHY AND ECOLOGICAL CULTURE

    Directory of Open Access Journals (Sweden)

    Kalimat M. Alilova

    2017-01-01

    Full Text Available Aim. The aim of the research is to study environmental problems related to the decline of culture, the importance of philosophy in overcoming private and personal interests as well as the unilateral approach of man in his relationship to nature. The study shows how philosophy can participate in the formation of ecological culture, a new ecological consciousness in man, while ecological culture is called upon to resist technocratic stereotypes and the course of history was aimed at preventing the biosphere from becoming deserted. Discussion. On the basis of the analysis of literary sources, we used the method of socio-cultural and socio-natural approaches based on the possibility of philosophy to introduce a new life into culture, new ecological values and new ecological principles. To solve these problems, environmental philosophy develops new theories. Representatives of different cultures, ethnic groups, nations, religions must learn to coexist with each other. We consider philosophy as a means of teaching rapprochement between peoples and creating new opportunities for understanding and improving the environmental situation. Cultural development makes it possible to assess the level of a man’s knowledge of nature, himself and the world around him. Ecological culture is a way of connecting man with nature on the basis of deeper knowledge and understanding. Philosophy says that you cannot move away from nature and be lauded over it since this will destroy culture. Rational doctrines tend to put a person above other living beings so the synthesis of philosophy with culture can have a positive ecological meaning. Conclusion. The findings obtained can be recommended for practical use in schools, starting from primary school, as well as in secondary special educational institutions and universities. It is necessary to work on the motivation and values of people, develop a common and ecological culture. Only a cultured person can move from

  19. Ecological restoration [book review

    Science.gov (United States)

    Eric J. Gustafson

    2010-01-01

    Ecological restoration has increased in prominence in recent years as environmental policies have slowed the rate of environmental degradation in many parts of the world and practitioners have looked for active ways to reverse the damage. Because of the vast number of types and contexts of degraded ecological systems, the field of ecological restoration is still very...

  20. Bacterial vaginosis - aftercare

    Science.gov (United States)

    Bacterial vaginosis (BV) is a type of vaginal infection. The vagina normally contains both healthy bacteria and unhealthy bacteria. BV occurs when more unhealthy bacteria grow than healthy bacteria. No one knows ...

  1. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  2. Diagnosis of bacterial infection

    African Journals Online (AJOL)

    direct or indirect evidence of a compatible bacterial pathogen. Inflammation may be .... cardinal features (fever, confusion, headache and neck stiffness). .... specificity, inappropriate indications or poor sampling technique may diminish this ...

  3. Methyl Methacrylate and Alpha-Methyl Styrene: New Strategy for Synthesis of Bloc Copolymers for Use in Potential Biomedical Applications Generated by an Ecologic Catalyst Called Maghnite (Algerian MMT

    Directory of Open Access Journals (Sweden)

    Moulkheir Ayat

    2016-10-01

    Strategy for Synthesis of Bloc Copolymers for Use in Potential Biomedical Applications Generated by an Ecologic Catalyst called Maghnite (Algerian MMT. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (3: 316-329 (doi: 10.9767/bcrec.11.3.571.316-329 Permalink/DOI: http://doi.org/10.9767/bcrec.11.3.571.316-329

  4. Diversity and succession of bacterial communities in the uterine fluid of postpartum metritic, endometritic and healthy dairy cows.

    Directory of Open Access Journals (Sweden)

    Thiago M A Santos

    Full Text Available The diversity of the uterine bacterial composition in dairy cows is still poorly understood, although the emerging picture has shown to be increasingly complex. Understanding the complexity and ecology of microorganisms in the uterus of postpartum dairy cows is critical for developing strategies to block their action in reproductive disorders, such as metritis/endometritis. Here, we used PCR-Denaturing Gradient Gel Electrophoresis (DGGE and DNA pyrosequencing to provide a comprehensive description of the uterine bacterial diversity and compare its succession in healthy, metritic and endometritic Holstein dairy cows at three intervals following calving. Samples were collected from 16 dairy cows housed in a dairy farm located in upstate New York. PCR-DGGE revealed a complex profile with extensive differences in the community structure. With few exceptions, clustering analysis grouped samples from cows presenting the same health status. Analysis of >65,000 high-quality 16S rRNA gene sequences showed that the uterine bacterial consortia, regardless of the health status, is mainly composed of members of the phyla Bacteroidetes, Fusobacteria, Firmicutes, Proteobacteria, and Tenericutes. In addition to these co-dominant phyla, sequences from Spirochaetes, Synergistetes, and Actinobacteria appear less frequently. It is possible that some sequences detected in the uterine fluid resulted from the presence of fecal or vaginal contaminants. Overall, the bacterial core community was different in uterine fluid of healthy cows, when compared to cows suffering from postpartum diseases, and the phylogenetic diversity in all the combined samples changed gradually over time. Particularly at the 34-36 days postpartum (DPP, the core community seemed to be specific for each health status. Our finding reveals that the uterine microbiota in dairy cows varies according with health status and DPP. Also, it adds further support to the hypothesis that there is uterine

  5. Philosophy of ecology

    CERN Document Server

    Brown, Bryson; Peacock, Kent A

    2011-01-01

    The most pressing problems facing humanity today - over-population, energy shortages, climate change, soil erosion, species extinctions, the risk of epidemic disease, the threat of warfare that could destroy all the hard-won gains of civilization, and even the recent fibrillations of the stock market - are all ecological or have a large ecological component. in this volume philosophers turn their attention to understanding the science of ecology and its huge implications for the human project. To get the application of ecology to policy or other practical concerns right, humanity needs a clear and disinterested philosophical understanding of ecology which can help identify the practical lessons of science. Conversely, the urgent practical demands humanity faces today cannot help but direct scientific and philosophical investigation toward the basis of those ecological challenges that threaten human survival. This book will help to fuel the timely renaissance of interest in philosophy of ecology that is now oc...

  6. Antibiotics promote aggregation within aquatic bacterial communities

    Directory of Open Access Journals (Sweden)

    Gianluca eCorno

    2014-07-01

    Full Text Available The release of antibiotics (AB into the environment poses several threats for human health due to potential development of ABresistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and productivity. New approaches are required to study the response of microbial communities rather than individual resistance genes. In this study a chemostat-based experiment with 4 coexisting bacterial strains has been performed to mimicking the response of a freshwater bacterial community to the presence of antibiotics in low and high doses. Bacterial abundance rapidly decreased by 75% in the presence of AB, independently of their concentration, and remained constant until the end of the experiment. The bacterial community was mainly dominated by Aeromonas hydrophila and Brevundimonas intermedia while the other two strains, Micrococcus luteus and Rhodococcus sp. never exceed 10%. Interestingly, the bacterial strains, which were isolated at the end of the experiment, were not AB-resistant, while reassembled communities composed of the 4 strains, isolated from treatments under AB stress, significantly raised their performance (growth rate, abundance in the presence of AB compared to the communities reassembled with strains isolated from the treatment without AB. By investigating the phenotypic adaptations of the communities subjected to the different treatments, we found that the presence of AB significantly increased co-aggregation by 5-6 fold.These results represent the first observation of co-aggregation as a successful strategy of AB resistance based on phenotype in aquatic bacterial communities, and can represent a fundamental step in the understanding of

  7. Using ecological production functions to link ecological ...

    Science.gov (United States)

    Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem services (ES) production. Although EPFs are acknowledged as being essential to improve environmental management, their use in ecological risk assessment has received relatively little attention. Ecological production functions may be defined as usable expressions (i.e., models) of the processes by which ecosystems produce ES, often including external influences on those processes. We identify key attributes of EPFs and discuss both actual and idealized examples of their use to inform decision making. Whenever possible, EPFs should estimate final, rather than intermediate, ES. Although various types of EPFs have been developed, we suggest that EPFs are more useful for decision making if they quantify ES outcomes, respond to ecosystem condition, respond to stressor levels or management scenarios, reflect ecological complexity, rely on data with broad coverage, have performed well previously, are practical to use, and are open and transparent. In an example using pesticides, we illustrate how EPFs with these attributes could enable the inclusion of ES in ecological risk assessment. The biggest challenges to ES inclusion are limited data sets that are easily adapted for use in modeling EPFs and generally poor understanding of linkages among ecological components and the processes that ultimately deliver the ES. We conclude by advocating for the incorporation into E

  8. Initial insights into bacterial succession during human decomposition.

    Science.gov (United States)

    Hyde, Embriette R; Haarmann, Daniel P; Petrosino, Joseph F; Lynne, Aaron M; Bucheli, Sibyl R

    2015-05-01

    Decomposition is a dynamic ecological process dependent upon many factors such as environment, climate, and bacterial, insect, and vertebrate activity in addition to intrinsic properties inherent to individual cadavers. Although largely attributed to microbial metabolism, very little is known about the bacterial basis of human decomposition. To assess the change in bacterial community structure through time, bacterial samples were collected from several sites across two cadavers placed outdoors to decompose and analyzed through 454 pyrosequencing and analysis of variable regions 3-5 of the bacterial 16S ribosomal RNA (16S rRNA) gene. Each cadaver was characterized by a change in bacterial community structure for all sites sampled as time, and decomposition, progressed. Bacteria community structure is variable at placement and before purge for all body sites. At bloat and purge and until tissues began to dehydrate or were removed, bacteria associated with flies, such as Ignatzschineria and Wohlfahrtimonas, were common. After dehydration and skeletonization, bacteria associated with soil, such as Acinetobacter, were common at most body sites sampled. However, more cadavers sampled through multiple seasons are necessary to assess major trends in bacterial succession.

  9. Bacterial Acclimation Inside an Aqueous Battery.

    Science.gov (United States)

    Dong, Dexian; Chen, Baoling; Chen, P

    2015-01-01

    Specific environmental stresses may lead to induced genomic instability in bacteria, generating beneficial mutants and potentially accelerating the breeding of industrial microorganisms. The environmental stresses inside the aqueous battery may be derived from such conditions as ion shuttle, pH gradient, free radical reaction and electric field. In most industrial and medical applications, electric fields and direct currents are used to kill bacteria and yeast. However, the present study focused on increasing bacterial survival inside an operating battery. Using a bacterial acclimation strategy, both Escherichia coli and Bacillus subtilis were acclimated for 10 battery operation cycles and survived in the battery for over 3 days. The acclimated bacteria changed in cell shape, growth rate and colony color. Further analysis indicated that electrolyte concentration could be one of the major factors determining bacterial survival inside an aqueous battery. The acclimation process significantly improved the viability of both bacteria E. coli and B. subtilis. The viability of acclimated strains was not affected under battery cycle conditions of 0.18-0.80 mA cm(-2) and 1.4-2.1 V. Bacterial addition within 1.0×10(10) cells mL(-1) did not significantly affect battery performance. Because the environmental stress inside the aqueous battery is specific, the use of this battery acclimation strategy may be of great potential for the breeding of industrial microorganisms.

  10. Game theory and plant ecology.

    Science.gov (United States)

    McNickle, Gordon G; Dybzinski, Ray

    2013-04-01

    The fixed and plastic traits possessed by a plant, which may be collectively thought of as its strategy, are commonly modelled as density-independent adaptations to its environment. However, plant strategies may also represent density- or frequency-dependent adaptations to the strategies used by neighbours. Game theory provides the tools to characterise such density- and frequency-dependent interactions. Here, we review the contributions of game theory to plant ecology. After briefly reviewing game theory from the perspective of plant ecology, we divide our review into three sections. First, game theoretical models of allocation to shoots and roots often predict investment in those organs beyond what would be optimal in the absence of competition. Second, game theoretical models of enemy defence suggest that an individual's investment in defence is not only a means of reducing its own tissue damage but also a means of deflecting enemies onto competitors. Finally, game theoretical models of trade with mutualistic partners suggest that the optimal trade may reflect competition for access to mutualistic partners among plants. In short, our review provides an accessible entrance to game theory that will help plant ecologists enrich their research with its worldview and existing predictions. © 2013 Blackwell Publishing Ltd/CNRS.

  11. The ecological importance of intraspecific variation.

    Science.gov (United States)

    Des Roches, Simone; Post, David M; Turley, Nash E; Bailey, Joseph K; Hendry, Andrew P; Kinnison, Michael T; Schweitzer, Jennifer A; Palkovacs, Eric P

    2018-01-01

    Human activity is causing wild populations to experience rapid trait change and local extirpation. The resulting effects on intraspecific variation could have substantial consequences for ecological processes and ecosystem services. Although researchers have long acknowledged that variation among species influences the surrounding environment, only recently has evidence accumulated for the ecological importance of variation within species. We conducted a meta-analysis comparing the ecological effects of variation within a species (intraspecific effects) with the effects of replacement or removal of that species (species effects). We evaluated direct and indirect ecological responses, including changes in abundance (or biomass), rates of ecological processes and changes in community composition. Our results show that intraspecific effects are often comparable to, and sometimes stronger than, species effects. Species effects tend to be larger for direct ecological responses (for example, through consumption), whereas intraspecific effects and species effects tend to be similar for indirect responses (for example, through trophic cascades). Intraspecific effects are especially strong when indirect interactions alter community composition. Our results summarize data from the first generation of studies examining the relative ecological effects of intraspecific variation. Our conclusions can help inform the design of future experiments and the formulation of strategies to quantify and conserve biodiversity.

  12. Bacterial Cell Mechanics.

    Science.gov (United States)

    Auer, George K; Weibel, Douglas B

    2017-07-25

    Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

  13. Biodegradability of bacterial surfactants.

    Science.gov (United States)

    Lima, Tânia M S; Procópio, Lorena C; Brandão, Felipe D; Carvalho, André M X; Tótola, Marcos R; Borges, Arnaldo C

    2011-06-01

    This work aimed at evaluating the biodegradability of different bacterial surfactants in liquid medium and in soil microcosms. The biodegradability of biosurfactants by pure and mixed bacterial cultures was evaluated through CO(2) evolution. Three bacterial strains, Acinetobacter baumanni LBBMA ES11, Acinetobacter haemolyticus LBBMA 53 and Pseudomonas sp. LBBMA 101B, used the biosurfactants produced by Bacillus sp. LBBMA 111A (mixed lipopeptide), Bacillus subtilis LBBMA 155 (lipopeptide), Flavobacterium sp. LBBMA 168 (mixture of flavolipids), Dietzia Maris LBBMA 191(glycolipid) and Arthrobacter oxydans LBBMA 201(lipopeptide) as carbon sources in minimal medium. The synthetic surfactant sodium dodecyl sulfate (SDS) was also mineralized by these microorganisms, but at a lower rate. CO(2) emitted by a mixed bacterial culture in soil microcosms with biosurfactants was higher than in the microcosm containing SDS. Biosurfactant mineralization in soil was confirmed by the increase in surface tension of the soil aqueous extracts after incubation with the mixed bacterial culture. It can be concluded that, in terms of biodegradability and environmental security, these compounds are more suitable for applications in remediation technologies in comparison to synthetic surfactants. However, more information is needed on structure of biosurfactants, their interaction with soil and contaminants and scale up and cost for biosurfactant production.

  14. Bacterial biofilms and antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Liliana Caldas-Arias

    2015-04-01

    Full Text Available Biofilms give to bacteria micro-environmental benefits; confers protection against antimicrobials. Bacteria have antibiotic resistance by conventional and unusual mechanisms leading to delayed wound healing, to increase recurrent chronic infections and nosocomial contamination of medical devices. Objective: This narrative review aims to introduce the characteristics of Bacteria-biofilms, antimicrobial resistance mechanisms and potential alternatives for prevention and control of its formation. Methods: Search strategy was performed on records: PubMed / Medline, Lilacs, Redalyc; with suppliers such as EBSCO and thesaurus MeSH and DeCS. Conclusions: Knowledge and research performance of biofilm bacteria are relevant in the search of technology for detection and measuring sensitivity to antibiotics. The identification of Bacterial-biofilms needs no-traditional microbiological diagnosis.

  15. Bacterial meningitis in children

    International Nuclear Information System (INIS)

    Marji, S.

    2007-01-01

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  16. Bacterial Community Succession During in situ Uranium Bioremediation: Spatial Similarities Along Controlled Flow Paths

    International Nuclear Information System (INIS)

    Hwang, Chiachi; Wu, Weimin; Gentry, Terry J.; Carley, Jack; Corbin, Gail A.; Carroll, Sue L.; Watson, David B.; Jardine, Phil M.; Zhou, Jizhong; Criddle, Craig S.; Fields, Matthew W.

    2009-01-01

    Bacterial community succession was investigated in a field-scale subsurface reactor formed by a series of wells that received weekly ethanol additions to re-circulating groundwater. Ethanol additions stimulated denitrification, metal reduction, sulfate reduction, and U(VI) reduction to sparingly soluble U(IV). Clone libraries of SSU rRNA gene sequences from groundwater samples enabled tracking of spatial and temporal changes over a 1.5 y period. Analyses showed that the communities changed in a manner consistent with geochemical variations that occurred along temporal and spatial scales. Canonical correspondence analysis revealed that the levels of nitrate, uranium, sulfide, sulfate, and ethanol strongly correlated with particular bacterial populations. As sulfate and U(VI) levels declined, sequences representative of sulfate-reducers and metal-reducers were detected at high levels. Ultimately, sequences associated with sulfate-reducing populations predominated, and sulfate levels declined as U(VI) remained at low levels. When engineering controls were compared to the population variation via canonical ordination, changes could be related to dissolved oxygen control and ethanol addition. The data also indicated that the indigenous populations responded differently to stimulation for bio-reduction; however, the two bio-stimulated communities became more similar after different transitions in an idiosyncratic manner. The strong associations between particular environmental variables and certain populations provide insight into the establishment of practical and successful remediation strategies in radionuclide-contaminated environments with respect to engineering controls and microbial ecology.

  17. Bacterial Community Succession During in situ Uranium Bioremediation: Spatial Similarities Along Controlled Flow Paths

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Chiachi; Wu, Weimin; Gentry, Terry J.; Carley, Jack; Corbin, Gail A.; Carroll, Sue L.; Watson, David B.; Jardine, Phil M.; Zhou, Jizhong; Criddle, Craig S.; Fields, Matthew W.

    2009-05-22

    Bacterial community succession was investigated in a field-scale subsurface reactor formed by a series of wells that received weekly ethanol additions to re-circulating groundwater. Ethanol additions stimulated denitrification, metal reduction, sulfate reduction, and U(VI) reduction to sparingly soluble U(IV). Clone libraries of SSU rRNA gene sequences from groundwater samples enabled tracking of spatial and temporal changes over a 1.5 y period. Analyses showed that the communities changed in a manner consistent with geochemical variations that occurred along temporal and spatial scales. Canonical correspondence analysis revealed that the levels of nitrate, uranium, sulfide, sulfate, and ethanol strongly correlated with particular bacterial populations. As sulfate and U(VI) levels declined, sequences representative of sulfate-reducers and metal-reducers were detected at high levels. Ultimately, sequences associated with sulfate-reducing populations predominated, and sulfate levels declined as U(VI) remained at low levels. When engineering controls were compared to the population variation via canonical ordination, changes could be related to dissolved oxygen control and ethanol addition. The data also indicated that the indigenous populations responded differently to stimulation for bio-reduction; however, the two bio-stimulated communities became more similar after different transitions in an idiosyncratic manner. The strong associations between particular environmental variables and certain populations provide insight into the establishment of practical and successful remediation strategies in radionuclide-contaminated environments with respect to engineering controls and microbial ecology.

  18. Endophytic bacterial diversity in the phyllosphere of Amazon Paullinia cupana associated with asymptomatic and symptomatic anthracnose.

    Science.gov (United States)

    Bogas, Andréa Cristina; Ferreira, Almir José; Araújo, Welington Luiz; Astolfi-Filho, Spartaco; Kitajima, Elliot Watanabe; Lacava, Paulo Teixeira; Azevedo, João Lúcio

    2015-01-01

    Endophytes colonize an ecological niche similar to that of phytopathogens, which make them candidate for disease suppression. Anthracnose is a disease caused by Colletotrichum spp., a phytopathogen that can infect guarana (Paullinia cupana), an important commercial crop in the Brazilian Amazon. We investigated the diversity of endophytic bacteria inhabiting the phyllosphere of asymptomatic and symptomatic anthracnose guarana plants. The PCR-denaturation gradient gel electrophoresis (PCR-DGGE) fingerprints revealed differences in the structure of the evaluated communities. Detailed analysis of endophytic bacteria composition using culture-dependent and 16S rRNA clone libraries revealed the presence of Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Acidobacteria phyla. Firmicutes comprised the majority of isolates in asymptomatic plants (2.40E(-4)). However, cloning and sequencing of 16S rRNA revealed differences at the genus level for Neisseria (1.4E(-4)), Haemophilus (2.1E(-3)) and Arsenophonus (3.6E(-5)) in asymptomatic plants, Aquicella (3.5E(-3)) in symptomatic anthracnose plants, and Pseudomonas (1.1E(-3)), which was mainly identified in asymptomatic plants. In cross-comparisons of the endophytic bacterial communities as a whole, symptomatic anthracnose plants contained higher diversity, as reflected in the Shannon-Weaver and Simpson indices estimation (P anthracnose can restructure endophytic bacterial communities by selecting certain strains in the phyllosphere of P. cupana. The understanding of these interactions is important for the development of strategies of biocontrol for Colletotrichum.

  19. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1997

    International Nuclear Information System (INIS)

    Wein, G.; Rosier, B.

    1997-01-01

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs

  20. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1998

    International Nuclear Information System (INIS)

    Wein, G.; Rosier, B.

    1998-01-01

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs

  1. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Wein, G.; Rosier, B.

    1998-12-31

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.

  2. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Wein, G.; Rosier, B.

    1997-12-31

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.

  3. Striding Toward Social Justice: The Ecologic Milieu of Physical Activity

    Science.gov (United States)

    Lee, Rebecca E.; Cubbin, Catherine

    2009-01-01

    Disparities in physical activity should be investigated in light of social justice principles. This manuscript critically evaluates evidence and trends in disparities research within an ecologic framework, focusing on multi-level factors such as neighborhood and racial discrimination that influence physical activity. Discussion focuses on strategies for integrating social justice into physical activity promotion and intervention programming within an ecologic framework. PMID:19098519

  4. 江南传统村落保护发展下的生态规划策略探讨%Ecological Planning Strategy under the Protection and Development of Traditional Villages in South Regions of the Yangtze River

    Institute of Scientific and Technical Information of China (English)

    龚晓芳; 董建

    2017-01-01

    In the current haze worsening situation, protection and development of traditional villages in South Regions of the Yangtze River not only need to be focused on the protection of cultural heritage, but also on the protection of the ecological environment. Aiming at the ecological environment issues of traditional villages in South Regions of the Yangtze River, this paper proposed the idea of"integrating into the ecological environment of the regional environment", and cooperating with the cluster growth of the regional environment, and"construction of the ecological network" for landscape village financial macro-control. The sponge city theory for reference, the "elastic sponge village ecological net frame" is expounded, according to the characteristics of the traditional village' s rich network in South Regions of the Yangtze River, and measures of constructing the ecological protection of traditional villages, as a reference for the guidance of ecological planning for traditional village in South Regions of the Yangtze River.%在现今雾霾日益恶化的情况下,江南传统村落的保护及发展,不仅需关注文化遗产的保护,更需关注生态环境的保护.针对江南传统村落的生态环境问题,提出"融入区域环境的生态引领思路",协同区域环境簇群式生长;提出"构建山水村融的生态网架"作为宏观调控传统村落生态格局.以海绵城市理论为借鉴,并根据江南传统村落水网丰富的特点提出"弹性化的海绵村落生态网架"构思,构筑传统村落生态保护的具体措施,为指导江南传统村落生态规划提供一定的参考.

  5. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...

  6. Marine ecology — some chemical aspects

    Science.gov (United States)

    Scheuer, Paul J.

    1982-11-01

    Relationships among biota on tropical coral reefs are frequently governed by chemical phenomena. This article describes some of the ecological events that may lead to a human intoxication known as ciguatera, and a few examples of the survival strategy that is used by physically unprotected gastropod mollusks.

  7. Multimodal Student Interaction Online: An Ecological Perspective

    Science.gov (United States)

    Berglund, Therese Ornberg

    2009-01-01

    This article describes the influence of tool and task design on student interaction in language learning at a distance. Interaction in a multimodal desktop video conferencing environment, FlashMeeting, is analyzed from an ecological perspective with two main foci: participation rates and conversational feedback strategies. The quantitative…

  8. The Netherlands and the world ecology

    International Nuclear Information System (INIS)

    Besselink, C.

    1994-01-01

    A short survey of the Dutch impact on the global environment is presented. The ecological costs of Dutch trade relations, both in the Netherlands and the rest of the world are examined. A strategy to attain a more sustainable society is provided

  9. Between Design and Ecology

    DEFF Research Database (Denmark)

    Bjørn, Mona Chor

    such vegetation, based on concepts and theories in plant community ecology. If these communities are based on local forbs there is a continuum in anthropogenic intervention from designed and intensively maintained to semi-natural herbaceous vegetation. Results from a large field experiment show that, after three...... colonised by grasses and eventually woody species. This thesis adds useful basic knowledge in plant community ecology and species-specific growth, which are relevant to research and planning in landscape architecture and ecology....

  10. Development of Ecological Buildings

    Directory of Open Access Journals (Sweden)

    Andrius Keizikas

    2011-04-01

    Full Text Available The article presents research on ecological buildings and their influence on the constructional sphere. The aim of the paper is to reveal the essence of ecological architecture showing substantial progress and its potential to stimulate architectural and technological growth. The article also describes relations between the ideas of ecological buildings and the ‘passive house’ concepts and aspects of development as well as describes the possibilities of improving building sustainability and energy efficiency. Article in Lithuanian

  11. The ecological economics: An ecological economics

    International Nuclear Information System (INIS)

    Castiblanco R, Carmenza

    2007-01-01

    Ecological Economics arise as a scientific discipline aimed to integrate concepts of economics, ecology, thermodynamics, ethic and other natural and social sciences in order to incorporate a biophysical and integrated perspective of the inter dependences between economies and environment, from a plural conception and a methodology beyond disciplines. Ecological Economics studies the black box of economic processes usually excluded of the traditional economics: thermodynamics and ecology. Although it is relatively a new field of study, it has been strengthening its theoretical framework with scientific basis and analytic principles that lead to its identification as a new discipline that show a whole new paradigm. The scope of this article is to show the conceptual and methodological bases, the main founders, approaches and central debates of this new discipline. This brief introduction is a preamble to the papers of the meeting Ecological Economics: a perspective for Colombia included in this number, that took place on September 22 - 27 of 2007, at the National University of Colombia at Bogota. During tree days national and international experts, professors, researchers, workers of environmental sector and people interested on environmental issues joined together to know the conceptual and methodological achievements reached of this discipline; as well as to analyse and evaluate the environmental problems of the country, from the systemic, interdisciplinary and general perspective that it promotes

  12. Water Microbiology. Bacterial Pathogens and Water

    Directory of Open Access Journals (Sweden)

    João P. S. Cabral

    2010-10-01

    Full Text Available Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water—cholera, typhoid fever and bacillary dysentery—is presented, focusing on the biology and ecology of the causal agents and on the diseases’ characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers. Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  13. Water microbiology. Bacterial pathogens and water.

    Science.gov (United States)

    Cabral, João P S

    2010-10-01

    Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water-cholera, typhoid fever and bacillary dysentery-is presented, focusing on the biology and ecology of the causal agents and on the diseases' characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment) and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers). Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  14. Dynamics in artifact ecologies

    DEFF Research Database (Denmark)

    Bødker, Susanne; Klokmose, Clemens Nylandsted

    2012-01-01

    We increasingly interact with multiple interactive artifacts with overlapping capabilities during our daily activities. It has previously been shown that the use of an interactive artifact cannot be understood in isolation, but artifacts must be understood as part of an artifact ecology, where...... artifacts influence the use of others. Understanding this interplay becomes more and more essential for interaction design as our artifact ecologies grow. This paper continues a recent discourse on artifact ecologies. Through interviews with iPhone users, we demonstrate that relationships between artifacts...... in artifact ecologies cannot be understood as static, instead they evolve dynamically over time. We provide activity theory-based concepts to explain these dynamics....

  15. Ecological risk assessment

    National Research Council Canada - National Science Library

    Suter, Glenn W; Barnthouse, L. W. (Lawrence W)

    2007-01-01

    Ecological risk assessment is commonly applied to the regulation of chemicals, the remediation of contaminated sites, the monitoring of importation of exotic organisms, the management of watersheds...

  16. Chemical ecology of fungi.

    Science.gov (United States)

    Spiteller, Peter

    2015-07-01

    Fungi are widespread in nature and have conquered nearly every ecological niche. Fungi occur not only in terrestrial but also in freshwater and marine environments. Moreover, fungi are known as a rich source of secondary metabolites. Despite these facts, the ecological role of many of these metabolites is still unknown and the chemical ecology of fungi has not been investigated systematically so far. This review intends to present examples of the various chemical interactions of fungi with other fungi, plants, bacteria and animals and to give an overview of the current knowledge of fungal chemical ecology.

  17. Microbiology of the phyllosphere: a playground for testing ecological concepts

    NARCIS (Netherlands)

    Meyer, K.M.; Leveau, J.H.J.

    2012-01-01

    Many concepts and theories in ecology are highly debated, because it is often difficult to design decisive tests with sufficient replicates. Examples include biodiversity theories, succession concepts, invasion theories, coexistence theories, and concepts of life history strategies. Microbiological

  18. Ecological Assessment of Lake Hora, Ethiopia, Using Benthic and ...

    African Journals Online (AJOL)

    Bheema

    Lake Hora needs protection management strategies to maintain its sustainable use. Key words: Benthic Fauna, Ethiopia, Lake Hora, Specimens, Weed-bed. 1. ..... Loam soils often contain a good amount of organic matter. 3.3. Ecological ...

  19. Substantial nutritional contribution of bacterial amino acids to earthworms and enchytraeids: A case study from organic grasslands

    DEFF Research Database (Denmark)

    Larsen, Thomas; Pollierer, Melanie M.; Holmstrup, Martin

    2016-01-01

    worms relied equally on bacterial and plant derived EAA. Our study provides answers to some of the long-standing questions in regards to the role of bacteria for earthworm nutrition. While bacterial EAA contribution to anecic worms was relatively modest, less than one-quarter, bacterial contribution...... to endogeic and enchytraeid worms was substantial comprising almost half of their EAA. Our findings are important for understanding how different ecological groups of terrestrial oligochaetes meet nutritional needs and partition food resources....

  20. [Bacterial biofilms and infection].

    Science.gov (United States)

    Lasa, I; Del Pozo, J L; Penadés, J R; Leiva, J

    2005-01-01

    In developed countries we tend to think of heart disease and the numerous forms of cancer as the main causes of mortality, but on a global scale infectious diseases come close, or may even be ahead: 14.9 million deaths in 2002 compared to cardiovascular diseases (16.9 million deaths) and cancer (7.1 million deaths) (WHO report 2004). The infectious agents responsible for human mortality have evolved as medical techniques and hygienic measures have changed. Modern-day acute infectious diseases caused by specialized bacterial pathogens such as diphtheria, tetanus, cholera, plague, which represented the main causes of death at the beginning of XX century, have been effectively controlled with antibiotics and vaccines. In their place, more than half of the infectious diseases that affect mildly immunocompromised patients involve bacterial species that are commensal with the human body; these can produce chronic infections, are resistant to antimicrobial agents and there is no effective vaccine against them. Examples of these infections are the otitis media, native valve endocarditis, chronic urinary infections, bacterial prostatitis, osteomyelitis and all the infections related to medical devices. Direct analysis of the surface of medical devices or of tissues that have been foci of chronic infections shows the presence of large numbers of bacteria surrounded by an exopolysaccharide matrix, which has been named the "biofilm". Inside the biofilm, bacteria grow protected from the action of the antibodies, phagocytic cells and antimicrobial treatments. In this article, we describe the role of bacterial biofilms in human persistent infections.

  1. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation...

  2. Bacterial fingerprints across Europe

    NARCIS (Netherlands)

    Glasner, Corinna

    2014-01-01

    Bacterial pathogens, such as Staphylococcus aureus and carbapenemase-producing Enterobacteriaceae (CPE), impose major threats to human health worldwide. Both have a ‘Jekyll & Hyde’ character, since they can be present as human commensals, but can also become harmful invasive pathogens especially

  3. Bacterial membrane proteomics.

    Science.gov (United States)

    Poetsch, Ansgar; Wolters, Dirk

    2008-10-01

    About one quarter to one third of all bacterial genes encode proteins of the inner or outer bacterial membrane. These proteins perform essential physiological functions, such as the import or export of metabolites, the homeostasis of metal ions, the extrusion of toxic substances or antibiotics, and the generation or conversion of energy. The last years have witnessed completion of a plethora of whole-genome sequences of bacteria important for biotechnology or medicine, which is the foundation for proteome and other functional genome analyses. In this review, we discuss the challenges in membrane proteome analysis, starting from sample preparation and leading to MS-data analysis and quantification. The current state of available proteomics technologies as well as their advantages and disadvantages will be described with a focus on shotgun proteomics. Then, we will briefly introduce the most abundant proteins and protein families present in bacterial membranes before bacterial membrane proteomics studies of the last years will be presented. It will be shown how these works enlarged our knowledge about the physiological adaptations that take place in bacteria during fine chemical production, bioremediation, protein overexpression, and during infections. Furthermore, several examples from literature demonstrate the suitability of membrane proteomics for the identification of antigens and different pathogenic strains, as well as the elucidation of membrane protein structure and function.

  4. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

    2017-01-01

    Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

  5. Batch medication of intestinal infections in nursery pigs—A randomised clinical trial on the efficacy of treatment strategy, type of antibiotic and bacterial load on average daily weight gain

    DEFF Research Database (Denmark)

    Weber, Nicolai Rosager; Pedersen, Ken Steen; Hansen, Christian Fink

    2017-01-01

    after weaning) on average daily weight gain (ADG); (2) to compare the effect of treatment with doxycycline or tylosine on diarrhoea prevalence, pathogenic bacterial load, and ADG; (3) to evaluate PCR testing of faecal pen floor samples as a diagnostic tool for determining the optimal time of treatment...... difference (p = 0.04) of mean diarrhoea prevalence on day 21 of the study between pens treated with tylosine (0.254, 95% CI: 0.184–0.324), and doxycycline (0.167, 95% CI: 0.124–0.210). The type of antibiotic compound was not found to have a significant effect on ADG (p = 0.209). (3) Pigs starting treatment...... was achieved when treatment was initiated 14 days after weaning in pens where intestinal pathogens were detected. Doxycycline was more effective in reducing diarrhoea and LI excretion levels than treatment with tylosine....

  6. Corticosteroids for Bacterial Keratitis

    Science.gov (United States)

    Srinivasan, Muthiah; Mascarenhas, Jeena; Rajaraman, Revathi; Ravindran, Meenakshi; Lalitha, Prajna; Glidden, David V.; Ray, Kathryn J.; Hong, Kevin C.; Oldenburg, Catherine E.; Lee, Salena M.; Zegans, Michael E.; McLeod, Stephen D.; Lietman, Thomas M.; Acharya, Nisha R.

    2013-01-01

    Objective To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers. Methods Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization. Main Outcome Measures The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation. Results Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (−0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, −0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, −0.31 to −0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (−0.37 to −0.04; P = .02). Conclusions We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers. Application to Clinical Practice Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers. PMID:21987582

  7. Alternatives to overcoming bacterial resistances: State-of-the-art.

    Science.gov (United States)

    Rios, Alessandra C; Moutinho, Carla G; Pinto, Flávio C; Del Fiol, Fernando S; Jozala, Angela; Chaud, Marco V; Vila, Marta M D C; Teixeira, José A; Balcão, Victor M

    2016-10-01

    Worldwide, bacterial resistance to chemical antibiotics has reached such a high level that endangers public health. Presently, the adoption of alternative strategies that promote the elimination of resistant microbial strains from the environment is of utmost importance. This review discusses and analyses several (potential) alternative strategies to current chemical antibiotics. Bacteriophage (or phage) therapy, although not new, makes use of strictly lytic phage particles as an alternative, or a complement, in the antimicrobial treatment of bacterial infections. It is being rediscovered as a safe method, because these biological entities devoid of any metabolic machinery do not possess any affinity whatsoever to eukaryotic cells. Lysin therapy is also recognized as an innovative antimicrobial therapeutic option, since the topical administration of preparations containing purified recombinant lysins with amounts in the order of nanograms, in infections caused by Gram-positive bacteria, demonstrated a high therapeutic potential by causing immediate lysis of the target bacterial cells. Additionally, this therapy exhibits the potential to act synergistically when combined with certain chemical antibiotics already available on the market. Another potential alternative antimicrobial therapy is based on the use of antimicrobial peptides (AMPs), amphiphilic polypeptides that cause disruption of the bacterial membrane and can be used in the treatment of bacterial, fungal and viral infections, in the prevention of biofilm formation, and as antitumoral agents. Interestingly, bacteriocins are a common strategy of bacterial defense against other bacterial agents, eliminating the potential opponents of the former and increasing the number of available nutrients in the environment for their own growth. They can be applied in the food industry as biopreservatives and as probiotics, and also in fighting multi-resistant bacterial strains. The use of antibacterial antibodies

  8. Effects of three different teaching strategies on academic ...

    African Journals Online (AJOL)

    Open Access DOWNLOAD FULL TEXT ... Ecology Achievement Test (EAT) was used as instrument for data collection. ... by Ministries of Education for biology teachers on how to make use of STS and CTS strategies when teaching ecology.

  9. Bacterial opportunism in fallow and meadow soils

    Czech Academy of Sciences Publication Activity Database

    Chmolowska, D.; Krištůfek, Václav; Elhottová, Dana; Laskowski, R.; Kozak, M.

    2010-01-01

    Roč. 9, č. 2 (2010), s. 8-17 ISSN 1336-1120 R&D Projects: GA MŠk LC06066 Grant - others:Jagiellonian University(PL) DS/BiNoZ/INoS/759/2009 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil microbial community * r/K strategy * opportunism Subject RIV: EH - Ecology, Behaviour

  10. Prevalence and antimicrobial resistance pattern of bacterial meningitis in Egypt

    Directory of Open Access Journals (Sweden)

    Shaban Lamyaa

    2009-09-01

    Full Text Available Abstract Infectious diseases are the leading cause of morbidity and mortality in the developing world. In Egypt bacterial diseases constitute a great burden, with several particular bacteria sustaining the leading role of multiple serious infections. This article addresses profound bacterial agents causing a wide array of infections including but not limited to pneumonia and meningitis. The epidemiology of such infectious diseases and the prevalence of Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae are reviewed in the context of bacterial meningitis. We address prevalent serotypes in Egypt, antimicrobial resistance patterns and efficacy of vaccines to emphasize the importance of periodic surveillance for appropriate preventive and treatment strategies.

  11. Ecological analyses and applications

    International Nuclear Information System (INIS)

    Brocksen, R.W.

    1977-01-01

    Progress is reported on the following: analysis of ecological impacts of construction and operation of nuclear power plants; fossil energy environmental project; ecological analysis of geothermal energy development; HUD modular integrated utility systems; expansion of uranium enrichment facilities at Portsmouth; environmental standard review plans; environmental assessment of cooling reservoirs; and analysis of fish impingement at power plants in the southeastern United States

  12. Ecology and economy

    International Nuclear Information System (INIS)

    Menard, M.; Bischoff, J.

    1980-01-01

    The green movement challenges workers' unions and socialists. Who are the 'Greens', and what do they want. Where do their theoretical fundamentals come from. Will an ecological economy be able to function. Are the 'Greens' leftists or dreamers fighting against progress. Arguments for trade unionists and socialists in the ecological controversy. (orig.) [de

  13. Ecological analyses and applications

    International Nuclear Information System (INIS)

    Kroodsma, R.L.; Craig, R.B.; Hildebrand, S.G.

    1978-01-01

    Progress is reported on the following: assessment of nuclear power plants; ecological analysis of uranium mining, milling, and fuel fabrication; environmental impact statements concerning uranium enrichment facilities; site evaluations for storage of radioactive wastes; ecological analysis of geothermal energy development; enhanced oil recovery; environmental monitoring plan for modular integrated utility systems; and fossil energy environmental project

  14. Terrestrial Ecology Guide.

    Science.gov (United States)

    Morrison, James W., Ed.; Hall, James A., Ed.

    This collection of study units focuses on the study of the ecology of land habitats. Considered are such topics as map reading, field techniques, forest ecosystem, birds, insects, small mammals, soils, plant ecology, preparation of terrariums, air pollution, photography, and essentials of an environmental studies program. Each unit contains…

  15. Children's Ecology Books.

    Science.gov (United States)

    Lussenhop, Martha

    Selected for this listing of children's books are fiction and non-fiction books which add to an understanding of ecology, broadly considered here as the study of the interrelationships of organisms to each other and their environment. General ecology, natural resources, man and his environment, evolution and adaptation, appreciation, survival,…

  16. [Bacterial biofilms as a natural form of existence of bacteria in the environment and host organism].

    Science.gov (United States)

    Romanova, Iu M; Gintsburg, A L

    2011-01-01

    Advances in microscopic analysis and molecular genetics research methods promoted the acquisition of evidence that natural bacteria populations exist predominately as substrate attached biofilms. Bacteria in biofilms are able to exchange signals and display coordinated activity that is inherent to multicellular organisms. Formation of biofilm communities turned out to be one of the main survival strategies of bacteria in their ecological niche. Bacteria in attached condition in biofilm are protected from the environmental damaging factors and effects of antibacterial substances in the environment and host organism during infection. According to contemporary conception, biofilm is a continuous layer of bacterial cells that are attached to a surface and each other, and contained in a biopolymer matrix. Such bacterial communities may be composed of bacteria of one or several species, and composed of actively functioning cells as well as latent and uncultured forms. Particular attention has recently been paid to the role of biofilms in the environment and host organism. Microorganisms form biofilm on any biotic and abiotic surfaces which creates serious problems in medicine and various areas of economic activity. Currently, it is established that biofilms are one of the pathogenetic factors of chronic inflection process formation. The review presents data on ubiquity of bacteria existence as biofilms, contemporary methods of microbial community analysis, structural-functional features of bacterial biofilms. Particular attention is paid to the role of biofilm in chronic infection process formation, heightened resistance to antibiotics of bacteria in biofilms and possible mechanisms of resistance. Screening approaches for agents against biofilms in chronic infections are discussed.

  17. Environmentally acceptable mobility in Europe: New strategies for passenger and goods transport. A contribution to ecologically compatible mobility. Documentation; Umweltgerecht mobil in Europa: Menschen und Gueter auf neuen Wegen. Ein Beitrag zur oekologisch vertraeglichen Mobilitaet. Dokumentation

    Energy Technology Data Exchange (ETDEWEB)

    Link, F.G. [Akademie fuer Natur- und Umweltschutz beim Ministerium fuer Umwelt und Verkehr des Landes Baden-Wuerttemberg, Stuttgart (Germany); Diekmann, P.; Holzwarth, J. [comps.] [Ministerium fuer Umwelt und Verkehr des Landes Baden-Wuerttemberg, Stuttgart (Germany)

    1998-11-01

    The traffic sector, with its transport systems and structures which for the most part are not ecologically acceptable, is a significant obstacle to sustainable development. As a contribution to a future-orientated, optimized consideration of both the need for mobility and the necessity of environmental protection, this volume presents big and small steps that can be taken to prevent traffic from the view of politicians, practicians and scientists in the field of passenger and goods transport. (orig.)

  18. Bacterial infec tions in travellers

    African Journals Online (AJOL)

    namely bacterial causes of travellers' diarrhoea and skin infections, as well as .... Vaccination: protective efficacy against typhoid may be overcome by ingesting a high bacterial load. Vaccine ..... preparation such as cream sauce. Only after ...

  19. Discovery of novel bacterial toxins by genomics and computational biology.

    Science.gov (United States)

    Doxey, Andrew C; Mansfield, Michael J; Montecucco, Cesare

    2018-06-01

    Hundreds and hundreds of bacterial protein toxins are presently known. Traditionally, toxin identification begins with pathological studies of bacterial infectious disease. Following identification and cultivation of a bacterial pathogen, the protein toxin is purified from the culture medium and its pathogenic activity is studied using the methods of biochemistry and structural biology, cell biology, tissue and organ biology, and appropriate animal models, supplemented by bioimaging techniques. The ongoing and explosive development of high-throughput DNA sequencing and bioinformatic approaches have set in motion a revolution in many fields of biology, including microbiology. One consequence is that genes encoding novel bacterial toxins can be identified by bioinformatic and computational methods based on previous knowledge accumulated from studies of the biology and pathology of thousands of known bacterial protein toxins. Starting from the paradigmatic cases of diphtheria toxin, tetanus and botulinum neurotoxins, this review discusses traditional experimental approaches as well as bioinformatics and genomics-driven approaches that facilitate the discovery of novel bacterial toxins. We discuss recent work on the identification of novel botulinum-like toxins from genera such as Weissella, Chryseobacterium, and Enteroccocus, and the implications of these computationally identified toxins in the field. Finally, we discuss the promise of metagenomics in the discovery of novel toxins and their ecological niches, and present data suggesting the existence of uncharacterized, botulinum-like toxin genes in insect gut metagenomes. Copyright © 2018. Published by Elsevier Ltd.

  20. Determinants of bacterial communities in Canadian agroforestry systems.

    Science.gov (United States)

    Banerjee, Samiran; Baah-Acheamfour, Mark; Carlyle, Cameron N; Bissett, Andrew; Richardson, Alan E; Siddique, Tariq; Bork, Edward W; Chang, Scott X

    2016-06-01

    Land-use change is one of the most important factors influencing soil microbial communities, which play a pivotal role in most biogeochemical and ecological processes. Using agroforestry systems as a model, this study examined the effects of land uses and edaphic properties on bacterial communities in three agroforestry types covering a 270 km soil-climate gradient in Alberta, Canada. Our results demonstrate that land-use patterns exert stronger effects on soil bacterial communities than soil zones in these agroforestry systems. Plots with trees in agroforestry systems promoted greater bacterial abundance and to some extent species richness, which was associated with more nutrient-rich soil resources. While Acidobacteria, Actinobacteria and Alphaproteobacteria were the dominant bacterial phyla and subphyla across land uses, Arthrobacter, Acidobacteria_Gp16, Burkholderia, Rhodanobacter and Rhizobium were the keystone taxa in these agroforestry systems. Soil pH and carbon contents emerged as the major determinants of bacterial community characteristics. We found non-random co-occurrence and modular patterns of soil bacterial communities, and these patterns were controlled by edaphic factors and not their taxonomy. Overall, this study highlights the drivers and co-occurrence patterns of soil microbial communities in agroforestry systems. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  1. Metamorphosis of a butterfly-associated bacterial community.

    Science.gov (United States)

    Hammer, Tobin J; McMillan, W Owen; Fierer, Noah

    2014-01-01

    Butterflies are charismatic insects that have long been a focus of biological research. They are also habitats for microorganisms, yet these microbial symbionts are little-studied, despite their likely importance to butterfly ecology and evolution. In particular, the diversity and composition of the microbial communities inhabiting adult butterflies remain uncharacterized, and it is unknown how the larval (caterpillar) and adult microbiota compare. To address these knowledge gaps, we used Illumina sequencing of 16S rRNA genes from internal bacterial communities associated with multiple life stages of the neotropical butterfly Heliconius erato. We found that the leaf-chewing larvae and nectar- and pollen-feeding adults of H. erato contain markedly distinct bacterial communities, a pattern presumably rooted in their distinct diets. Larvae and adult butterflies host relatively small and similar numbers of bacterial phylotypes, but few are common to both stages. The larval microbiota clearly simplifies and reorganizes during metamorphosis; thus, structural changes in a butterfly's bacterial community parallel those in its own morphology. We furthermore identify specific bacterial taxa that may mediate larval and adult feeding biology in Heliconius and other butterflies. Although male and female Heliconius adults differ in reproductive physiology and degree of pollen feeding, bacterial communities associated with H. erato are not sexually dimorphic. Lastly, we show that captive and wild individuals host different microbiota, a finding that may have important implications for the relevance of experimental studies using captive butterflies.

  2. Mapping and predictive variations of soil bacterial richness across France.

    Directory of Open Access Journals (Sweden)

    Sébastien Terrat

    Full Text Available Although numerous studies have demonstrated the key role of bacterial diversity in soil functions and ecosystem services, little is known about the variations and determinants of such diversity on a nationwide scale. The overall objectives of this study were i to describe the bacterial taxonomic richness variations across France, ii to identify the ecological processes (i.e. selection by the environment and dispersal limitation influencing this distribution, and iii to develop a statistical predictive model of soil bacterial richness. We used the French Soil Quality Monitoring Network (RMQS, which covers all of France with 2,173 sites. The soil bacterial richness (i.e. OTU number was determined by pyrosequencing 16S rRNA genes and related to the soil characteristics, climatic conditions, geomorphology, land use and space. Mapping of bacterial richness revealed a heterogeneous spatial distribution, structured into patches of about 111km, where the main drivers were the soil physico-chemical properties (18% of explained variance, the spatial descriptors (5.25%, 1.89% and 1.02% for the fine, medium and coarse scales, respectively, and the land use (1.4%. Based on these drivers, a predictive model was developed, which allows a good prediction of the bacterial richness (R2adj of 0.56 and provides a reference value for a given pedoclimatic condition.

  3. Mapping and predictive variations of soil bacterial richness across France.

    Science.gov (United States)

    Terrat, Sébastien; Horrigue, Walid; Dequiedt, Samuel; Saby, Nicolas P A; Lelièvre, Mélanie; Nowak, Virginie; Tripied, Julie; Régnier, Tiffanie; Jolivet, Claudy; Arrouays, Dominique; Wincker, Patrick; Cruaud, Corinne; Karimi, Battle; Bispo, Antonio; Maron, Pierre Alain; Chemidlin Prévost-Bouré, Nicolas; Ranjard, Lionel

    2017-01-01

    Although numerous studies have demonstrated the key role of bacterial diversity in soil functions and ecosystem services, little is known about the variations and determinants of such diversity on a nationwide scale. The overall objectives of this study were i) to describe the bacterial taxonomic richness variations across France, ii) to identify the ecological processes (i.e. selection by the environment and dispersal limitation) influencing this distribution, and iii) to develop a statistical predictive model of soil bacterial richness. We used the French Soil Quality Monitoring Network (RMQS), which covers all of France with 2,173 sites. The soil bacterial richness (i.e. OTU number) was determined by pyrosequencing 16S rRNA genes and related to the soil characteristics, climatic conditions, geomorphology, land use and space. Mapping of bacterial richness revealed a heterogeneous spatial distribution, structured into patches of about 111km, where the main drivers were the soil physico-chemical properties (18% of explained variance), the spatial descriptors (5.25%, 1.89% and 1.02% for the fine, medium and coarse scales, respectively), and the land use (1.4%). Based on these drivers, a predictive model was developed, which allows a good prediction of the bacterial richness (R2adj of 0.56) and provides a reference value for a given pedoclimatic condition.

  4. Brood size modifications affect plumage bacterial assemblages of European starlings.

    Science.gov (United States)

    Lucas, Françoise S; Moureau, Benoit; Jourdie, Violaine; Heeb, Philipp

    2005-02-01

    During reproduction, birds face trade-offs between time and energy devoted to parental effort and traits associated with self-maintenance. We manipulated brood sizes to investigate the effects of such trade-offs on feather bacterial densities and the structure of bacterial assemblages on feathers in adult European starlings, Sturnus vulgaris, and in vitro feather degradation. As predicted by a trade-off between parental effort and self-maintenance, we found that birds with enlarged broods had more free-living bacteria on their feathers than birds with reduced broods. Furthermore, we found a significant interaction between brood manipulation and original brood size on free-living bacterial densities suggesting that the trade-off is mediated by the adults' initial reproductive investment. In contrast, brood size manipulations had no significant effect on densities of attached bacteria. Using ribosomal intergenic spacer analysis (RISA), we demonstrated that brood manipulations significantly modified the structure (band pattern) of feather-degrading bacterial assemblages, but had no significant effect on their richness (number of bands) or the in vitro feather degradation. In vitro feather degradation varied in relation to the premanipulation brood size and positively with the richness of the feather degrading bacterial community. Besides brood manipulation effect, we found that ecological factors and individual traits, such as the age, the nest location or the capture date, shaped bacterial assemblages and feather degradation capacities.

  5. Metamorphosis of a butterfly-associated bacterial community.

    Directory of Open Access Journals (Sweden)

    Tobin J Hammer

    Full Text Available Butterflies are charismatic insects that have long been a focus of biological research. They are also habitats for microorganisms, yet these microbial symbionts are little-studied, despite their likely importance to butterfly ecology and evolution. In particular, the diversity and composition of the microbial communities inhabiting adult butterflies remain uncharacterized, and it is unknown how the larval (caterpillar and adult microbiota compare. To address these knowledge gaps, we used Illumina sequencing of 16S rRNA genes from internal bacterial communities associated with multiple life stages of the neotropical butterfly Heliconius erato. We found that the leaf-chewing larvae and nectar- and pollen-feeding adults of H. erato contain markedly distinct bacterial communities, a pattern presumably rooted in their distinct diets. Larvae and adult butterflies host relatively small and similar numbers of bacterial phylotypes, but few are common to both stages. The larval microbiota clearly simplifies and reorganizes during metamorphosis; thus, structural changes in a butterfly's bacterial community parallel those in its own morphology. We furthermore identify specific bacterial taxa that may mediate larval and adult feeding biology in Heliconius and other butterflies. Although male and female Heliconius adults differ in reproductive physiology and degree of pollen feeding, bacterial communities associated with H. erato are not sexually dimorphic. Lastly, we show that captive and wild individuals host different microbiota, a finding that may have important implications for the relevance of experimental studies using captive butterflies.

  6. Predictive systems ecology.

    Science.gov (United States)

    Evans, Matthew R; Bithell, Mike; Cornell, Stephen J; Dall, Sasha R X; Díaz, Sandra; Emmott, Stephen; Ernande, Bruno; Grimm, Volker; Hodgson, David J; Lewis, Simon L; Mace, Georgina M; Morecroft, Michael; Moustakas, Aristides; Murphy, Eugene; Newbold, Tim; Norris, K J; Petchey, Owen; Smith, Matthew; Travis, Justin M J; Benton, Tim G

    2013-11-22

    Human societies, and their well-being, depend to a significant extent on the state of the ecosystems that surround them. These ecosystems are changing rapidly usually in response to anthropogenic changes in the environment. To determine the likely impact of environmental change on ecosystems and the best ways to manage them, it would be desirable to be able to predict their future states. We present a proposal to develop the paradigm of predictive systems ecology, explicitly to understand and predict the properties and behaviour of ecological systems. We discuss the necessary and desirable features of predictive systems ecology models. There are places where predictive systems ecology is already being practised and we summarize a range of terrestrial and marine examples. Significant challenges remain but we suggest that ecology would benefit both as a scientific discipline and increase its impact in society if it were to embrace the need to become more predictive.

  7. Spatial ecology across scales.

    Science.gov (United States)

    Hastings, Alan; Petrovskii, Sergei; Morozov, Andrew

    2011-04-23

    The international conference 'Models in population dynamics and ecology 2010: animal movement, dispersal and spatial ecology' took place at the University of Leicester, UK, on 1-3 September 2010, focusing on mathematical approaches to spatial population dynamics and emphasizing cross-scale issues. Exciting new developments in scaling up from individual level movement to descriptions of this movement at the macroscopic level highlighted the importance of mechanistic approaches, with different descriptions at the microscopic level leading to different ecological outcomes. At higher levels of organization, different macroscopic descriptions of movement also led to different properties at the ecosystem and larger scales. New developments from Levy flight descriptions to the incorporation of new methods from physics and elsewhere are revitalizing research in spatial ecology, which will both increase understanding of fundamental ecological processes and lead to tools for better management.

  8. MELA: Modelling in Ecology with Location Attributes

    Directory of Open Access Journals (Sweden)

    Ludovica Luisa Vissat

    2016-10-01

    Full Text Available Ecology studies the interactions between individuals, species and the environment. The ability to predict the dynamics of ecological systems would support the design and monitoring of control strategies and would help to address pressing global environmental issues. It is also important to plan for efficient use of natural resources and maintenance of critical ecosystem services. The mathematical modelling of ecological systems often includes nontrivial specifications of processes that influence the birth, death, development and movement of individuals in the environment, that take into account both biotic and abiotic interactions. To assist in the specification of such models, we introduce MELA, a process algebra for Modelling in Ecology with Location Attributes. Process algebras allow the modeller to describe concurrent systems in a high-level language. A key feature of concurrent systems is that they are composed of agents that can progress simultaneously but also interact - a good match to ecological systems. MELA aims to provide ecologists with a straightforward yet flexible tool for modelling ecological systems, with particular emphasis on the description of space and the environment. Here we present four example MELA models, illustrating the different spatial arrangements which can be accommodated and demonstrating the use of MELA in epidemiological and predator-prey scenarios.

  9. What is dental ecology?

    Science.gov (United States)

    Cuozzo, Frank P; Sauther, Michelle L

    2012-06-01

    Teeth have long been used as indicators of primate ecology. Early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. Our study of Lemur catta at the Beza Mahafaly Special Reserve, Madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are not dentally adapted. Interpreting these data was only possible by combining our areas of expertise (dental anatomy [FC] and primate ecology [MS]). By integrating theoretical, methodological, and applied aspects of both areas of research, we adopted the term "dental ecology"-defined as the broad study of how teeth respond to the environment. Specifically, we view dental ecology as an interpretive framework using teeth as a vehicle for understanding an organism's ecology, which builds upon earlier work, but creates a new synthesis of anatomy and ecology that is only possible with detailed knowledge of living primates. This framework includes (1) identifying patterns of dental pathology and tooth use-wear, within the context of feeding ecology, behavior, habitat variation, and anthropogenic change, (2) assessing ways in which dental development and biogeochemical signals can reflect habitat, environmental change and/or stress, and (3) how dental microstructure and macro-morphology are adapted to, and reflect feeding ecology. Here we define dental ecology, provide a short summary of the development of this perspective, and place our new work into this context. Copyright © 2012 Wiley Periodicals, Inc.

  10. Guiding bioprocess design by microbial ecology.

    Science.gov (United States)

    Volmer, Jan; Schmid, Andreas; Bühler, Bruno

    2015-06-01

    Industrial bioprocess development is driven by profitability and eco-efficiency. It profits from an early stage definition of process and biocatalyst design objectives. Microbial bioprocess environments can be considered as synthetic technical microbial ecosystems. Natural systems follow Darwinian evolution principles aiming at survival and reproduction. Technical systems objectives are eco-efficiency, productivity, and profitable production. Deciphering technical microbial ecology reveals differences and similarities of natural and technical systems objectives, which are discussed in this review in view of biocatalyst and process design and engineering strategies. Strategies for handling opposing objectives of natural and technical systems and for exploiting and engineering natural properties of microorganisms for technical systems are reviewed based on examples. This illustrates the relevance of considering microbial ecology for bioprocess design and the potential for exploitation by synthetic biology strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Ecological neo-colonialism?

    International Nuclear Information System (INIS)

    Lejon, E.

    1996-01-01

    In this chapter of the book author deals with the ecological aspects of chemical industry and energy production as well as the European Communities energy strategy. Author thinks that the current situation suggests that the very primitive fossil energy age will be overlapping with even more primitive atomic age in the majority of the European states for a certain time period. From the thermodynamic point of view, this kind of a development means that we are shifting from energy processes utilizing the temperature of 260 grad C for boiling eggs as well as for heating the rooms to the temperature of 20 grad C, to the energy processes of uranium cleaving with the temperature of 55,000 grad C in order to provide the same functions. This is not only primitive and vulgar but completely ineffective and senseless from the economic point of view. This kind of a development has a clearly destructive effect, negative environmental effect not speaking about the possible disastrous effect. The plutonium economy is going to become a tragic straitjacket, binding the enormous investments and research means. In addition, this kind of economics is going to tie the production structures into the obsolete economies and it is going to prevent the development of the production basis that will become dominant in the advanced economies in a very short time period. Therefore the plutonium economy will further reinforce the neo-colonialist relations typical for the economic relations between the East and the West.Some statistical data in atomic energy development in Europe are given

  12. Bacterial identification and subtyping using DNA microarray and DNA sequencing.

    Science.gov (United States)

    Al-Khaldi, Sufian F; Mossoba, Magdi M; Allard, Marc M; Lienau, E Kurt; Brown, Eric D

    2012-01-01

    The era of fast and accurate discovery of biological sequence motifs in prokaryotic and eukaryotic cells is here. The co-evolution of direct genome sequencing and DNA microarray strategies not only will identify, isotype, and serotype pathogenic bacteria, but also it will aid in the discovery of new gene functions by detecting gene expressions in different diseases and environmental conditions. Microarray bacterial identification has made great advances in working with pure and mixed bacterial samples. The technological advances have moved beyond bacterial gene expression to include bacterial identification and isotyping. Application of new tools such as mid-infrared chemical imaging improves detection of hybridization in DNA microarrays. The research in this field is promising and future work will reveal the potential of infrared technology in bacterial identification. On the other hand, DNA sequencing by using 454 pyrosequencing is so cost effective that the promise of $1,000 per bacterial genome sequence is becoming a reality. Pyrosequencing technology is a simple to use technique that can produce accurate and quantitative analysis of DNA sequences with a great speed. The deposition of massive amounts of bacterial genomic information in databanks is creating fingerprint phylogenetic analysis that will ultimately replace several technologies such as Pulsed Field Gel Electrophoresis. In this chapter, we will review (1) the use of DNA microarray using fluorescence and infrared imaging detection for identification of pathogenic bacteria, and (2) use of pyrosequencing in DNA cluster analysis to fingerprint bacterial phylogenetic trees.

  13. Ecological problems in the food industry

    Directory of Open Access Journals (Sweden)

    Božović Milan

    2002-01-01

    Full Text Available In regard to the development of agricultural and food technologies Yugoslavia up till now has not had a developed strategy of "development of the environment" - an ecological strategy, nor has it in that respect had clearly defined political scientifically-based strategies. Current efforts to define developmental concepts are almost completely neglected, foremost in the "promotion of new ecologically justified technologies" and the formation of national programs of sustainable development. World trends in this area are already directed to the production and promotion of so-called "healthy food" which, designated in several ways, is becoming more and more present on the tables of developed countries. Yugoslavia, beside its current economic difficulties, has great potential and a elastic chance to follow world trends and completely satisfy the EU standards EVRO-EMA and world ecological standards ISO 14 000 by the quality implementation of well planned ecologically and economically rational programs. n order to undertake appropriate measures for "sustainable development", it s previously necessary to assess the problem and objectively establish the status.

  14. Batch medication of intestinal infections in nursery pigs—A randomised clinical trial on the efficacy of treatment strategy, type of antibiotic and bacterial load on average daily weight gain

    DEFF Research Database (Denmark)

    Weber, Nicolai Rosager; Pedersen, Ken Steen; Hansen, Christian Fink

    2017-01-01

    as a randomised clinical trial in three Danish pig herds and included 1047 nursery pigs, distributed over 10 batches and 78 pens. The objectives of this study were: (1) to assess the effect of four 5-day treatment strategies (initiated at clinical outbreak of diarrhoea or at fixed time points 14, 21, or 28 days...

  15. Bacterial Human Virulence Genes across Diverse Habitats As Assessed by In silico Analysis of Environmental Metagenomes

    DEFF Research Database (Denmark)

    Søborg, Ditte A; Hendriksen, Niels B; Kilian, Mogens

    2016-01-01

    of natural environments in the evolution of bacterial virulence. Twenty four bacterial virulence genes were analyzed in 46 diverse environmental metagenomic datasets, representing various soils, seawater, freshwater, marine sediments, hot springs, the deep-sea, hypersaline mats, microbialites, gutless worms......The occurrence and distribution of clinically relevant bacterial virulence genes across natural (non-human) environments is not well understood. We aimed to investigate the occurrence of homologs to bacterial human virulence genes in a variety of ecological niches to better understand the role...... in non-human environments point to an important ecological role of the genes for the activity and survival of environmental bacteria. Furthermore, the high degree of sequence conservation between several of the environmental and clinical genes suggests common ancestral origins....

  16. Plant-associated microbiomes in arid lands: diversity, ecology and biotechnological potential

    KAUST Repository

    Soussi, Asma

    2015-08-28

    Background: Aridification is a worldwide serious threat directly affecting agriculture and crop production. In arid and desert areas, it has been found that microbial diversity is huge, built of microorganisms able to cope with the environmental harsh conditions by developing adaptation strategies. Plants growing in arid lands or regions facing prolonged abiotic stresses such as water limitation and salt accumulation have also developed specific physiological and molecular stress responses allowing them to thrive under normally unfavorable conditions. Scope: Under such extreme selection pressures, special root-associated bacterial assemblages, endowed with capabilities of plant growth promotion (PGP) and extremophile traits, are selected by the plants. In this review, we provide a general overview on the microbial diversity in arid lands and deserts versus specific microbial assemblages associated with plants. The ecological drivers that shape this diversity, how plant-associated microbiomes are selected, and their biotechnological potential are discussed. Conclusions: Selection and recruitment of the plant associated bacterial assemblages is mediated by the combination of the bio-pedo-agroclimatic conditions and the plant species or varieties. Diversity and functional redundancy of these associated PGPR makes them very active in supporting plant improvement, health and resistance to drought, salt and related stresses. Implementing proper biotechnological applications of the arid and desert-adapted PGPR constitute the challenge to be raised.

  17. [Applied ecology: retrospect and prospect].

    Science.gov (United States)

    He, Xingyuan; Zeng, Dehui

    2004-10-01

    Applied ecology is evolved into a principal part of modern ecology that rapidly develops. The major stimulus for the development of applied ecology roots in seeking the solutions for the problems of human populations, resources and environments. Through four decades, the science of applied ecology has been becoming a huge group of disciplines. The future for the applied ecology should concern more with human-influenced and managed ecosystems, and acknowledge humans as the components of ecosystems. Nowadays and in future, the top-priorities in applied ecology should include following fields: sustainable ecosystems and biosphere, ecosystem services and ecological design, ecological assessment of genetically modified organisms, ecology of biological invasions, epidemical ecology, ecological forecasting, ecological process and its control. The authors believe that the comprehensive and active research hotspots coupled some new traits would occur around these fields in foreseeable future.

  18. Structure of bacterial lipopolysaccharides.

    Science.gov (United States)

    Caroff, Martine; Karibian, Doris

    2003-11-14

    Bacterial lipopolysaccharides are the major components of the outer surface of Gram-negative bacteria They are often of interest in medicine for their immunomodulatory properties. In small amounts they can be beneficial, but in larger amounts they may cause endotoxic shock. Although they share a common architecture, their structural details exert a strong influence on their activity. These molecules comprise: a lipid moiety, called lipid A, which is considered to be the endotoxic component, a glycosidic part consisting of a core of approximately 10 monosaccharides and, in "smooth-type" lipopolysaccharides, a third region, named O-chain, consisting of repetitive subunits of one to eight monosaccharides responsible for much of the immunospecificity of the bacterial cell.

  19. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  20. Bacterial control of cyanobacteria

    CSIR Research Space (South Africa)

    Ndlela, Luyanda L

    2017-08-01

    Full Text Available of biological control appears to be direct contact. • Ndlela, L. L. et al. (2016) ‘An overview of cyanobacterial bloom occurrences and research in Africa over the last decade’, Harmful Algae, 60 • Gumbo, J.R. et al. (2010) The Isolation and identification... of Predatory Bacteria from a Microcystis algal Bloom.. African Journal of Biotechnology, 9. *Special acknowledgement goes to the National Research foundation for funding this presentation Bacterial control of cyanobacteria Luyanda...

  1. Education in ecology

    International Nuclear Information System (INIS)

    Marek, R.

    1993-01-01

    It is not enough to convey knowledge, insights and attitudes if education in ecology is to have fruitful effects. Space and opportunity for action and creativity must be provided in addition. This includes personal consumer habits (eating, transport, hygiene, leisure activities etc.); an individual workplace - in this case school - that can be shaped according to ecological needs. Beyond this, ecological maturation should not be confined to, but should transcend school, for instance in youth groups, citizens' committees, political parties. If school does not inspire action - including action outside school -then education in ecology could be smothered by the Midas effect, where all life is reduced to material, to the curriculum in this case. This book presents ecological projects that have been tried at schools. They aim at an education in ecology that is oriented to the pupil and open to experience. They could be an incentive for colleagues to conduct similar projects at their schools. The projects work from the pupils' own experience and aim at concrete action and activities in his or her own environment. They should encourage teachers to venture outside the classroom with the pupils and teach ecology where it takes place. (orig.) [de

  2. Bacterial growth kinetics

    International Nuclear Information System (INIS)

    Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.

    1989-01-01

    Quantitative measurement of bacterial growth may be made using a radioassay technique. This method measures, by scintillation counting, the 14 CO 2 derived from the bacterial metabolism of a 14 C-labeled substrate. Mathematical growth models may serve as reliable tools for estimation of the generation rate constant (or slope of the growth curve) and provide a basis for evaluating assay performance. Two models, i.e., exponential and logistic, are proposed. Both models yielded an accurate fit to the data from radioactive measurement of bacterial growth. The exponential model yielded high precision values of the generation rate constant, with an average relative standard deviation of 1.2%. Under most conditions the assay demonstrated no changes in the slopes of growth curves when the number of bacteria per inoculation was changed. However, the radiometric assay by scintillation method had a growth-inhibiting effect on a few strains of bacteria. The source of this problem was thought to be hypersensitivity to trace amounts of toluene remaining on the detector

  3. XRD and solid state 13C-NMR evaluation of the crystallinity enhancement of 13C-labeled bacterial cellulose biosynthesized by Komagataeibacter xylinus under different stimuli: A comparative strategy of analyses.

    Science.gov (United States)

    Meza-Contreras, Juan C; Manriquez-Gonzalez, Ricardo; Gutiérrez-Ortega, José A; Gonzalez-Garcia, Yolanda

    2018-05-22

    The production and crystallinity of 13 C bacterial cellulose (BC) was examined in static culture of Komagataeibacter xylinus with different chemical and physical stimuli: the addition of NaCl or cloramphenicol as well as exposure to a magnetic field or to UV light. Crystalline BC biosynthesized under each stimulus was studied by XRD and solid state 13 C NMR analyses. All treatments produced BC with enhanced crystallinity over 90% (XRD) and 80% (NMR) compared to the control (83 and 76%, respectively) or to Avicel (77 and 62%, respectively). The XRD data indicated that the crystallite size was 80-85 Å. Furthermore, changes on the allomorphs (I α and I β ) ratio tendency of BC samples addressed to the stimuli were estimated using the C4 signal from 13 C NMR data. These results showed a decrease of the allomorph I α (3%) when BC was biosynthesized with UV light and chloramphenicol compared to control (58.79%). In contrast, the BC obtained with NaCl increased up to 60.31% of the I α allomorph ratio. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Recent Developments in Ecological Economics

    DEFF Research Database (Denmark)

    Reader with published articles within the field of ecological economics, mostly from 1997 - 2007......Reader with published articles within the field of ecological economics, mostly from 1997 - 2007...

  5. Evolution of tolerance to PCBs and susceptibility to a bacterial pathogen (Vibrio harveyi) in Atlantic killifish (Fundulus heteroclitus) from New Bedford (MA, USA) harbor

    International Nuclear Information System (INIS)

    Nacci, Diane; Huber, Marina; Champlin, Denise; Jayaraman, Saro; Cohen, Sarah; Gauger, Eric; Fong, Allison; Gomez-Chiarri, Marta

    2009-01-01

    A population of the non-migratory estuarine fish Fundulus heteroclitus (Atlantic killifish) resident to New Bedford (NB), Massachusetts, USA, an urban harbor highly contaminated with polychlorinated biphenyls (PCBs), demonstrates recently evolved tolerance to some aspects of PCB toxicity. PCB toxicology, ecological theory, and some precedence supported expectations of increased susceptibility to pathogens in NB killifish. However, laboratory bacterial challenges of the marine pathogen Vibrio harveyi to wild fish throughout the reproductive season and to their mature laboratory-raised progeny demonstrated comparable survival by NB and reference killifish, and improved survival by NB males. These results are inconsistent with hypothesized trade-offs of adaptation, and suggest that evolved tolerance in NB killifish may include mechanisms that minimize the immunosuppressive effects of PCBs. Compensatory strategies of populations persisting in highly contaminated environments provide a unique perspective for understanding the long-term ecological effects of toxic chemicals. - Killifish resident to a highly PCB-contaminated estuary survive pathogenic bacterial challenges well, suggesting their tolerance to PCB immunosuppression

  6. Complex adaptive systems ecology

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2003-01-01

    In the following, I will analyze two articles called Complex Adaptive Systems EcologyI & II (Molin & Molin, 1997 & 2000). The CASE-articles are some of the more quirkyarticles that have come out of the Molecular Microbial Ecology Group - a groupwhere I am currently making observational studies....... They are the result of acooperation between Søren Molin, professor in the group, and his brother, JanMolin, professor at Department of Organization and Industrial Sociology atCopenhagen Business School. The cooperation arises from the recognition that bothmicrobial ecology and sociology/organization theory works...

  7. Quantitative plant ecology

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com) The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement...... and statistical modelling of plant species abundance and the relevant ecological processes that control species abundance. The focus on statistical modelling and likelihood function based methods also means that more algorithm based methods, e.g. ordination techniques and boosted regression tress...

  8. Batch medication of intestinal infections in nursery pigs—A randomised clinical trial on the efficacy of treatment strategy, type of antibiotic and bacterial load on average daily weight gain

    OpenAIRE

    Weber, Nicolai Rosager; Pedersen, Ken Steen; Hansen, Christian Fink; Denwood, Matthew; Hjulsager, Charlotte Kristiane; Nielsen, Jens Peter

    2017-01-01

    Introduction: Previous research projects have demonstrated the need for better diagnostic tools to support decisions on medication strategies for infections caused by Escherichia coli F4 (F4) and F18 (F18), Lawsonia intracellularis (LI) and Brachyspira pilosicoli (PILO). This study was carried out as a randomised clinical trial in three Danish pig herds and included 1047 nursery pigs, distributed over 10 batches and 78 pens. The objectives of this study were: (1) to assess the effect of four ...

  9. Challenges of ecological restoration

    DEFF Research Database (Denmark)

    Halme, Panu; Allen, Katherine A.; Aunins, Ainars

    2013-01-01

    we introduce northern forests as an ecosystem, discuss the historical and recent human impact and provide a brief status report on the ecological restoration projects and research already conducted there. Based on this discussion, we argue that before any restoration actions commence, the ecology......The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many...... on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here...

  10. Ecological Provinces of Minnesota

    Data.gov (United States)

    Minnesota Department of Natural Resources — This coverage provides information for the first level of the Ecological Classification System. The boundaries of the polygons of this coverage were derived from...

  11. Market Squid Ecology Dataset

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains ecological information collected on the major adult spawning and juvenile habitats of market squid off California and the US Pacific Northwest....

  12. Ecological risk estimation

    International Nuclear Information System (INIS)

    Bartell, S.M.; Gardner, R.H.; O'Neill, R.V.

    1992-01-01

    Ecological risk assessment, the process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors, is being developed by the US EPA as a tool for decision making. This book presents one approach to risk assessment-that of applying laboratory toxicity data within an ecosystem model to predict the potential ecological consequences of toxic chemicals. Both Standard Water Column Model (SWACOM), using zooplankton and fish, and Monte Carlo simulations are discussed in detail, along with quantitative explanations for many responses. Simplifying assumptions are explicitly presented. The final chapter discusses strengths, weaknesses, and future directions of the approach. The book is appropriate for anyone who does or uses ecological risk assessment methodologies

  13. Green Turtle Trophic Ecology

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently conducting a study of green sea turtle (Chelonia mydas) trophic ecology in the eastern Pacific. Tissue samples and stable carbon and stable...

  14. Ecological Sections of Minnesota

    Data.gov (United States)

    Minnesota Department of Natural Resources — This coverage provides information for the second level of the Ecological Classification System. The boundaries of the polygons of this coverage were derived from...

  15. The French ecological movement

    International Nuclear Information System (INIS)

    Sansen, Bernard

    1977-01-01

    The analysis of the ecological Movement in France is presented: its organisation, its topics, its position with respect to the main political trends. The accent is put in particular on the antinuclear contestation [fr

  16. Biosemiotics and ecological monitoring

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio

    2001-01-01

    of the qualitative and relational aspects that can only be grasped by considering the semiotic networks operative in complex ecological and cultural systems. In this paper, it is suggested that a biosemiotic approach to ecology may prove useful for the modelling process, which in turn will allow the construction...... of meaningful monitoring systems. It is also contended that a biosemiotic approach may also serve to better integrate our understanding and monitoring of ecosystems into the cultural process of searching for (human) sustainability....

  17. Sraffa and ecological economics

    OpenAIRE

    Verger, Yoann

    2015-01-01

    References to Sraffa and to the neo-Ricardian school is something quite customary in ecological economics. By looking at contributions in this area since the beginning of ecological economics and at contributions on environmental problem from the neo-Ricardian school, we see that a connection between both school still has to be made. This connection should be articulated around the initial aim of Sraffa: to develop a new paradigm, competing against the neoclassical one. Only then it will be p...

  18. Translational ecology for hydrogeology.

    Science.gov (United States)

    Schlesinger, William H

    2013-01-01

    Translational ecology--a special discipline aimed to improve the accessibility of science to policy makers--will help hydrogeologists contribute to the solution of pressing environmental problems. Patterned after translational medicine, translational ecology is a partnership to ensure that the right science gets done in a timely fashion, so that it can be communicated to those who need it. © 2013, National Ground Water Association.

  19. Bacterial Biofilm Control by Perturbation of Bacterial Signaling Processes

    Directory of Open Access Journals (Sweden)

    Tim Holm Jakobsen

    2017-09-01

    Full Text Available The development of effective strategies to combat biofilm infections by means of either mechanical or chemical approaches could dramatically change today’s treatment procedures for the benefit of thousands of patients. Remarkably, considering the increased focus on biofilms in general, there has still not been invented and/or developed any simple, efficient and reliable methods with which to “chemically” eradicate biofilm infections. This underlines the resilience of infective agents present as biofilms and it further emphasizes the insufficiency of today’s approaches used to combat chronic infections. A potential method for biofilm dismantling is chemical interception of regulatory processes that are specifically involved in the biofilm mode of life. In particular, bacterial cell to cell signaling called “Quorum Sensing” together with intracellular signaling by bis-(3′-5′-cyclic-dimeric guanosine monophosphate (cyclic-di-GMP have gained a lot of attention over the last two decades. More recently, regulatory processes governed by two component regulatory systems and small non-coding RNAs have been increasingly investigated. Here, we review novel findings and potentials of using small molecules to target and modulate these regulatory processes in the bacterium Pseudomonas aeruginosa to decrease its pathogenic potential.

  20. [Using ecology thinking reconstructing traditional agronomy: role of production ecology].

    Science.gov (United States)

    Wang, Song-Liang

    2012-08-01

    Traditional agronomy, as a discipline or specialty, is originated from the reductionism thinking of neoteric experimental sciences and motivated by the great success of industrialized revolution, but loses the ensemble grasp of the relationships between agricultural organisms and their resources and environment, i.e., agroecosystem mechanism. Moreover, due to the excessively relying on exogenous fossil energy input and the monoculture with a few highly productive crop cultivars, the agricultural interior sustainability has unceasingly lost, making our mankind facing the double crises of grain security and food safety. Therefore, it is imperative to reconstruct the traditional agronomy and its educational system. In this paper, the author proposed to link traditional agronomy with ecology, establishing agroecology as the core subject and agroecosystem management as the core applied system, and in particular, establishing 'production ecology' to fill up the wide gap between the crop cultivation and farming system and the crop genetics and breeding, the two second grade disciplines under agronomy. Ideologically and methodologically, this proposal could provide disciplinary, scientific, and educational bases to authentically implement the strategy of sustainable development of agriculture.

  1. Building Theory at the Intersection of Ecological Sustainability and Strategic Management

    DEFF Research Database (Denmark)

    Borland, Helen; Ambrosini, Véronique; Lindgreen, Adam

    2016-01-01

    This article builds theory at the intersection of ecological sustainability and strategic management literature—specifically, in relation to dynamic capabilities literature. By combining industrial organization economics–based, resource-based, and dynamic capability–based views, it is possible...... to develop a better understanding of the strategies that businesses may follow, depending on their managers’ assumptions about ecological sustainability. To develop innovative strategies for ecological sustainability, the dynamic capabilities framework needs to be extended. In particular, the sensing...... sustainability. Finally, this approach offers opportunities for managers and academics to identify, categorize, and exploit business strategies for ecological sustainability....

  2. Dual-In/Out strategy for genes integration into bacterial chromosome: a novel approach to step-by-step construction of plasmid-less marker-less recombinant E. coli strains with predesigned genome structure

    Directory of Open Access Journals (Sweden)

    Biryukova Irina V

    2008-08-01

    Full Text Available Abstract Background The development of modern producer strains with metabolically engineered pathways poses special problems that often require manipulating many genes and expressing them individually at different levels or under separate regulatory controls. The construction of plasmid-less marker-less strains has many advantages for the further practical exploitation of these bacteria in industry. Such producer strains are usually constructed by sequential chromosome modifications including deletions and integration of genetic material. For these purposes complex methods based on in vitro and in vivo recombination processes have been developed. Results Here, we describe the new scheme of insertion of the foreign DNA for step-by-step construction of plasmid-less marker-less recombinant E. coli strains with chromosome structure designed in advance. This strategy, entitled as Dual-In/Out, based on the initial Red-driven insertion of artificial φ80-attB sites into desired points of the chromosome followed by two site-specific recombination processes: first, the φ80 system is used for integration of the recombinant DNA based on selective marker-carrier conditionally-replicated plasmid with φ80-attP-site, and second, the λ system is used for excision of inserted vector part, including the plasmid ori-replication and the marker, flanked by λ-attL/R-sites. Conclusion The developed Dual-In/Out strategy is a rather straightforward, but convenient combination of previously developed recombination methods: phages site-specific and general Red/ET-mediated. This new approach allows us to detail the design of future recombinant marker-less strains, carrying, in particular, rather large artificial insertions that could be difficult to introduce by usually used PCR-based Recombineering procedure. The developed strategy is simple and could be particularly useful for construction of strains for the biotechnological industry.

  3. Radiology of bacterial pneumonia

    International Nuclear Information System (INIS)

    Vilar, Jose; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-01-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings

  4. Radiology of bacterial pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Jose E-mail: vilar_jlu@gva.es; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-08-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings.

  5. Benefits of ecological engineering practices

    NARCIS (Netherlands)

    Van den Boomen, R.; Chaudhuri, N.; Heeb, J.; Jenssen, P.; Kalin, M.; Schönborn, A.; Brüll, A.; Van Bohemen, H.; Costanza, R.; Mitsch, W.J.

    2011-01-01

    With the intention to further promote the field of ecological engineering and the solutions it provides, a workshop on “Benefits of Ecological Engineering Practices” was held 3 Dec 2009. It was conducted by the International Ecological Engineering Society in Paris at the conference “Ecological

  6. Ecological approaches to human nutrition.

    Science.gov (United States)

    DeClerck, Fabrice A J; Fanzo, Jessica; Palm, Cheryl; Remans, Roseline

    2011-03-01

    Malnutrition affects a large number of people throughout the developing world. Approaches to reducing malnutrition rarely focus on ecology and agriculture to simultaneously improve human nutrition and environmental sustainability. However, evidence suggests that interdisciplinary approaches that combine the knowledge bases of these disciplines can serve as a central strategy in alleviating hidden hunger for the world's poorest. To describe the role that ecological knowledge plays in alleviating hidden hunger, considering human nutrition as an overlooked ecosystem service. We review existing literature and propose a framework that expands on earlier work on econutrition. We provide novel evidence from case studies conducted by the authors in western Kenya and propose a framework for interdisciplinary collaboration to alleviate hidden hunger, increase agricultural productivity, and improve environmental sustainability. Our review supports the concept that an integrated approach will impact human nutrition. We provide evidence that increased functional agrobiodiversity can alleviate anemia, and interventions that contribute to environmental sustainability can have both direct and indirect effects on human health and nutritional well-being. Integrated and interdisciplinary approaches are critical to reaching development goals. Ecologists must begin to consider not only how their field can contribute to biodiversity conservation, but also, the relationship between biodiversity and provisioning of nontraditional ecosystem services such as human health. Likewise, nutritionists and agronomists must recognize that many of the solutions to increasing human wellbeing and health can best be achieved by focusing on a healthy environment and the conservation of ecosystem services.

  7. Morphomechanics of bacterial biofilms undergoing anisotropic differential growth

    Science.gov (United States)

    Zhang, Cheng; Li, Bo; Huang, Xiao; Ni, Yong; Feng, Xi-Qiao

    2016-10-01

    Growing bacterial biofilms exhibit a number of surface morphologies, e.g., concentric wrinkles, radial ridges, and labyrinthine networks, depending on their physiological status and nutrient access. We explore the mechanisms underlying the emergence of these greatly different morphologies. Ginzburg-Landau kinetic method and Fourier spectral method are integrated to simulate the morphological evolution of bacterial biofilms. It is shown that the morphological instability of biofilms is triggered by the stresses induced by anisotropic and heterogeneous bacterial expansion, and involves the competition between membrane energy and bending energy. Local interfacial delamination further enriches the morphologies of biofilms. Phase diagrams are established to reveal how the anisotropy and spatial heterogeneity of growth modulate the surface patterns. The mechanics of three-dimensional microbial morphogenesis may also underpin self-organization in other development systems and provide a potential strategy for engineering microscopic structures from bacterial aggregates.

  8. Hydrocarbon pollutants shape bacterial community assembly of harbor sediments

    KAUST Repository

    Barbato, Marta

    2016-02-02

    Petroleum pollution results in co-contamination by different classes of molecules, entailing the occurrence of marine sediments difficult to remediate, as in the case of the Ancona harbor (Mediterranean Sea, Italy). Autochthonous bioaugmentation (ABA), by exploiting the indigenous microbes of the environment to be treated, could represent a successful bioremediation strategy. In this perspective we aimed to i) identify the main drivers of the bacterial communities\\' richness in the sediments, ii) establish enrichment cultures with different hydrocarbon pollutants evaluating their effects on the bacterial communities\\' composition, and iii) obtain a collection of hydrocarbon degrading bacteria potentially exploitable in ABA. The correlation between the selection of different specialized bacterial populations and the type of pollutants was demonstrated by culture-independent analyses, and by establishing a collection of bacteria with different hydrocarbon degradation traits. Our observations indicate that pollution dictates the diversity of sediment bacterial communities and shapes the ABA potential in harbor sediments.

  9. Asymptomatic Bacteriuria and Bacterial Interference.

    Science.gov (United States)

    Nicolle, Lindsay E

    2015-10-01

    Asymptomatic bacteriuria is very common. In healthy women, asymptomatic bacteriuria increases with age, from women age 80 years, but is uncommon in men until after age 50 years. Individuals with underlying genitourinary abnormalities, including indwelling devices, may also have a high frequency of asymptomatic bacteriuria, irrespective of age or gender. The prevalence is very high in residents of long-term-care facilities, from 25% to 50% of women and 15% to 40% of men. Escherichia coli is the most frequent organism isolated, but a wide variety of other organisms may occur. Bacteriuria may be transient or persist for a prolonged period. Pregnant women with asymptomatic bacteriuria identified in early pregnancy and who are untreated have a risk of pyelonephritis later in pregnancy of 20% to 30%. Bacteremia is frequent in bacteriuric subjects following mucosal trauma with bleeding, with 5% to 10% of patients developing severe sepsis or septic shock. These two groups with clear evidence of negative outcomes should be screened for bacteriuria and appropriately treated. Asymptomatic bacteriuria in other populations is benign and screening and treatment are not indicated. Antimicrobial treatment has no benefits but is associated with negative outcomes including reinfection with antimicrobial resistant organisms and a short-term increased frequency of symptomatic infection post-treatment. The observation of increased symptomatic infection post-treatment, however, has led to active investigation of bacterial interference as a strategy to prevent symptomatic episodes in selected high risk patients.

  10. Collective decisions among bacterial viruses

    Science.gov (United States)

    Joh, Richard; Mileyko, Yuriy; Voit, Eberhard; Weitz, Joshua

    2010-03-01

    For many temperate bacteriophages, the decision of whether to kill hosts or enter a latent state depends on the multiplicity of infection. In this talk, I present a quantitative model of gene regulatory dynamics to describe how phages make collective decisions within host cells. Unlike most previous studies, the copy number of viral genomes is treated as a variable. In the absence of feedback loops, viral mRNA transcription is expected to be proportional to the viral copy number. However, when there are nonlinear feedback loops in viral gene regulation, our model shows that gene expression patterns are sensitive to changes in viral copy number and there can be a domain of copy number where the system becomes bistable. Hence, the viral copy number is a key control parameter determining host cell fates. This suggests that bacterial viruses can respond adaptively to changes in population dynamics, and can make alternative decisions as a bet-hedging strategy. Finally, I present a stochastic version of viral gene regulation and discuss speed-accuracy trade-offs in the context of cell fate determination by viruses.

  11. Distributions of Bacterial Generalists among the Guts of Birds ...

    Science.gov (United States)

    Complex distributions of bacterial taxa within diverse animal microbiomes have inspired ecological and biogeographical approaches to revealing the functions of taxa that may be most important for host health. Of particular interest are bacteria that find many diverse habitats suitable for growth and remain competitive amongst finely-tuned host specialists. While previous work has focused on identifying these specialists, here our aims were to 1) identify generalist taxa, 2) identify taxonomic clades with enriched generalist diversity, and 3) describe the distribution of the largest generalist groups among hosts. We analyzed existing bacterial rRNA tag-sequencing data (v6) available on VAMPs (vamps.mbl.edu) from the microbiomes of 12 host species (106 samples total) spanning birds, mammals, and fish for generalist taxa using the CLAM test. OTUs with approximately equal abundance and a minimum of 10 reads in two hosts were classified as generalists. Generalist OTUs (n=2,982) were found in all hosts tested. Bacterial families Alcaligenaceae and Burkholderiaceae were significantly enriched with generalists OTUs compared to other families. Bacterial families such as Bacteroidaceae and Lachnospiraceae significantly lacked generalists OTUs compared to other families. Enterobacteriaceae, Peptostreptococcaceae, and Erysipelotrichaceae more so than other bacterial families were widely distributed and abundant in birds, mammals, and fish suggesting that these taxa mainta

  12. Bacterial phylogeny structures soil resistomes across habitats

    Science.gov (United States)

    Forsberg, Kevin J.; Patel, Sanket; Gibson, Molly K.; Lauber, Christian L.; Knight, Rob; Fierer, Noah; Dantas, Gautam

    2014-05-01

    Ancient and diverse antibiotic resistance genes (ARGs) have previously been identified from soil, including genes identical to those in human pathogens. Despite the apparent overlap between soil and clinical resistomes, factors influencing ARG composition in soil and their movement between genomes and habitats remain largely unknown. General metagenome functions often correlate with the underlying structure of bacterial communities. However, ARGs are proposed to be highly mobile, prompting speculation that resistomes may not correlate with phylogenetic signatures or ecological divisions. To investigate these relationships, we performed functional metagenomic selections for resistance to 18 antibiotics from 18 agricultural and grassland soils. The 2,895 ARGs we discovered were mostly new, and represent all major resistance mechanisms. We demonstrate that distinct soil types harbour distinct resistomes, and that the addition of nitrogen fertilizer strongly influenced soil ARG content. Resistome composition also correlated with microbial phylogenetic and taxonomic structure, both across and within soil types. Consistent with this strong correlation, mobility elements (genes responsible for horizontal gene transfer between bacteria such as transposases and integrases) syntenic with ARGs were rare in soil by comparison with sequenced pathogens, suggesting that ARGs may not transfer between soil bacteria as readily as is observed between human pathogens. Together, our results indicate that bacterial community composition is the primary determinant of soil ARG content, challenging previous hypotheses that horizontal gene transfer effectively decouples resistomes from phylogeny.

  13. Bacteriophage-Based Bacterial Wilt Biocontrol for an Environmentally Sustainable Agriculture

    OpenAIRE

    ?lvarez, Bel?n; Biosca, Elena G.

    2017-01-01

    Bacterial wilt diseases caused by Ralstonia solanacearum, R. pseudosolanacearum, and R. syzygii subsp. indonesiensis (former R. solanacearum species complex) are among the most important plant diseases worldwide, severely affecting a high number of crops and ornamentals. Difficulties of bacterial wilt control by non-biological methods are related to effectiveness, bacterial resistance and environmental impact. Alternatively, a great many biocontrol strategies have been carried out, with the a...

  14. Molecular ecological network analyses.

    Science.gov (United States)

    Deng, Ye; Jiang, Yi-Huei; Yang, Yunfeng; He, Zhili; Luo, Feng; Zhou, Jizhong

    2012-05-30

    Understanding the interaction among different species within a community and their responses to environmental changes is a central goal in ecology. However, defining the network structure in a microbial community is very challenging due to their extremely high diversity and as-yet uncultivated status. Although recent advance of metagenomic technologies, such as high throughout sequencing and functional gene arrays, provide revolutionary tools for analyzing microbial community structure, it is still difficult to examine network interactions in a microbial community based on high-throughput metagenomics data. Here, we describe a novel mathematical and bioinformatics framework to construct ecological association networks named molecular ecological networks (MENs) through Random Matrix Theory (RMT)-based methods. Compared to other network construction methods, this approach is remarkable in that the network is automatically defined and robust to noise, thus providing excellent solutions to several common issues associated with high-throughput metagenomics data. We applied it to determine the network structure of microbial communities subjected to long-term experimental warming based on pyrosequencing data of 16 S rRNA genes. We showed that the constructed MENs under both warming and unwarming conditions exhibited topological features of scale free, small world and modularity, which were consistent with previously described molecular ecological networks. Eigengene analysis indicated that the eigengenes represented the module profiles relatively well. In consistency with many other studies, several major environmental traits including temperature and soil pH were found to be important in determining network interactions in the microbial communities examined. To facilitate its application by the scientific community, all these methods and statistical tools have been integrated into a comprehensive Molecular Ecological Network Analysis Pipeline (MENAP), which is open

  15. Evidence for Ecological Flexibility in the Cosmopolitan Genus Curtobacterium

    OpenAIRE

    Chase, Alexander B.; Arevalo, Philip; Polz, Martin F.; Berlemont, Renaud; Martiny, Jennifer B. H.

    2016-01-01

    Assigning ecological roles to bacterial taxa remains imperative to understanding how microbial communities will respond to changing environmental conditions. Here we analyze the genus Curtobacterium as it was found to be the most abundant taxon in a leaf litter community in southern California. Traditional characterization of this taxon predominantly associates it as the causal pathogen in the agricultural crops of dry beans. Therefore, we seek to conduct a broad investigation into this genus...

  16. Perspectives on economics and ecology

    Energy Technology Data Exchange (ETDEWEB)

    O`Neill, R.V.

    1995-02-01

    As we move toward the twenty-first century, the overlap and synergism between economics and ecology demands our scientific attention. But in the intellectual excitement of seeing this new field emerge, we must not lose sight of the underlying global dynamics that are driving the pending merger. Simply stated: the population bomb has not been defused. The media and ecologists have simply fatigued of repeating the obvious. The combination of human population growth and increasing per capita impact is placing irreconcilable demands on the global biotic system. We can reduce per capita demands with technology and recycling. But such strategies simply delay the inevitable unless the human population asymptotes. of course, the population will reach a limit. The choice is between a series of global crises and a reasoned plan for the future. But for Global Sustainability to avoid becoming a cruel and unattainable fantasy, plans must include human population control and economics.

  17. In Search of Ecological Ethics

    Directory of Open Access Journals (Sweden)

    Catarina Jahnel de Oliveira

    2013-12-01

    Full Text Available In the scope of social science, studies dealing with environmental issues have gained prominence in recent years. Given the intense and profound changes the capitalist system has brought to society, culmina ng in the current environmental crisis, science and philosophy have sought ways to overcome the contradic s found in our current ethical model. In this sense, the objetive of this paper is, from a review of the related literature, to present ecological ethics as an alternative that points the way to the formula of strategies aimed at sustainability, since this ethical discourse, broaching issues such as anthropocentrism and moral competence, leads to a redefinition of the relationship between humans and their environment

  18. Key Issues Concerning Biolog Use for Aerobic and Anaerobic Freshwater Bacterial Community-Level Physiological Profiling

    Science.gov (United States)

    Christian, Bradley W.; Lind, Owen T.

    2006-06-01

    Bacterial heterotrophy in aquatic ecosystems is important in the overall carbon cycle. Biolog MicroPlates provide information into the metabolic potential of bacteria involved in carbon cycling. Specifically, Biolog EcoPlatesTM were developed with ecologically relevant carbon substrates to allow investigators to measure carbon substrate utilization patterns and develop community-level physiological profiles from natural bacterial assemblages. However, understanding of the functionality of these plates in freshwater research is limited. We explored several issues of EcoPlate use for freshwater bacterial assemblages including inoculum density, incubation temperature, non-bacterial color development, and substrate selectivity. Each of these has various effects on plate interpretation. We offer suggestions and techniques to resolve these interpretation issues. Lastly we propose a technique to allow EcoPlate use in anaerobic freshwater bacterial studies.

  19. Yes! There are resilient generalizations (or "laws") in ecology.

    Science.gov (United States)

    Linquist, Stefan; Gregory, T Ryan; Elliott, Tyler A; Saylor, Brent; Kremer, Stefan C; Cottenie, Karl

    2016-06-01

    ABSTRACT It is often argued that ecological communities admit of no useful generalizations or "laws" because these systems are especially prone to contingent historical events. Detractors respond that this argument assumes an overly stringent definition of laws of nature. Under a more relaxed conception, it is argued that ecological laws emerge at the level of communities and elsewhere. A brief review of this debate reveals an issue with deep philosophical roots that is unlikely to be resolved by a better understanding of generalizations in ecology. We therefore propose a strategy for transforming the conceptual question about the nature of ecological laws into a set of empirically tractable hypotheses about the relative re- silience of ecological generalizations across three dimensions: taxonomy, habitat type, and scale. These hypotheses are tested using a survey of 240 meta-analyses in ecology. Our central finding is that generalizations in community ecology are just as prevalent and as resilient as those in population or ecosystem ecology. These findings should help to establish community ecology as a generality-seeking science as opposed to a science of case studies. It also supports the capacity for ecologists, working at any of the three levels, to inform matters of public policy.

  20. Marx, Engels and Ecology

    Directory of Open Access Journals (Sweden)

    Michael Löwy

    2017-11-01

    Full Text Available This is a brief survey of Marx and Engels’ views on ecology, from the viewpoint of their relevance for 21th Century ecosocialism. While there are some serious limitations in the way both consider the “development of productive forces”, there are powerfull insights in their discussion of the destructive consequences of capitalist expansion for the environment - an expansion that generates a disastrous metabolic rift in the exchanges between human societies and nature. Some ecological Marxists distinguish between “first stage ecosocialists” - who believe that Marx analyses on ecological issues are too incomplete and dated to be of real relevance today - and “second stage ecosocialists” that emphasize the contemporary methodological significance of Marx’s ecological critique of capitalism. This paper tries to argue for a third position (which probably could be accepted by several people of the two groups above: Marx and Engels discussion on ecological issues is incomplete and dated, but inspite these shortcomings, it has real relevance and methodological significance today.

  1. Interim balance: Ecology

    International Nuclear Information System (INIS)

    Kogon, E.; Jungk, R.

    1981-01-01

    Subjects: The ecology problem - world wide. Sectoral balances: The examples of energy, transportation, chemistry, agriculture and food industry, water supply. Destruction of nature and human discord. Conservatives in our political parties and their views on environmental protection. Alliance between reds and 'greens', integration between reds and greens. The Rhine initiative. Lead respects no borders, experiences of citizens' action groups in Lothringia and the Saar district. International airport Munich-II/comments by a protestant. 'Give priority to life'/A hearing on environmental protection. 4:96 - 'greens' in the Bremen Senate. Policy in a hard-hearing world/psychology of citizens' action groups. Critical ecological research and scientific establishment. Full productivity and ecology. The deluge to follow/Hints on how to build an ark. Symbiosis is more than coexistence/Ecologists' social theory. Throwing in two hundred elementary particles/on the way to an ecological concept of science. Scientific journals. Alternative literature. Teaching model for a teaching subject 'ecology'. (orig.) [de

  2. Making ecological models adequate

    Science.gov (United States)

    Getz, Wayne M.; Marshall, Charles R.; Carlson, Colin J.; Giuggioli, Luca; Ryan, Sadie J.; Romañach, Stephanie; Boettiger, Carl; Chamberlain, Samuel D.; Larsen, Laurel; D'Odorico, Paolo; O'Sullivan, David

    2018-01-01

    Critical evaluation of the adequacy of ecological models is urgently needed to enhance their utility in developing theory and enabling environmental managers and policymakers to make informed decisions. Poorly supported management can have detrimental, costly or irreversible impacts on the environment and society. Here, we examine common issues in ecological modelling and suggest criteria for improving modelling frameworks. An appropriate level of process description is crucial to constructing the best possible model, given the available data and understanding of ecological structures. Model details unsupported by data typically lead to over parameterisation and poor model performance. Conversely, a lack of mechanistic details may limit a model's ability to predict ecological systems’ responses to management. Ecological studies that employ models should follow a set of model adequacy assessment protocols that include: asking a series of critical questions regarding state and control variable selection, the determinacy of data, and the sensitivity and validity of analyses. We also need to improve model elaboration, refinement and coarse graining procedures to better understand the relevancy and adequacy of our models and the role they play in advancing theory, improving hind and forecasting, and enabling problem solving and management.

  3. The ecological century

    Energy Technology Data Exchange (ETDEWEB)

    Worthington, E. B.

    1981-01-01

    This essay attempts to reconstruct the evolution of Ecology as the scientific basis for environmental conservation and human progress, as seen through the eyes of a biologist who has exercised that science during a number of tasks in various parts of the world over most of the twentieth century. From its beginnings in evolutionary thinking during the nineteenth century, ecology emerged from natural history at the beginning of the twentieth. At first the running was made by botanists; but this was soon followed by zoologists, who dealt with more mobile communities. The first quarter-century was mainly exploratory; the second was mainly descriptive (although biological exploration was still dominant in the tropics). The third quarter saw ecology developing into an experimental science, and, as the environmental revolution got into its stride, ecology became organized both nationally and internationally. Although the term is now often misused and sometimes misunderstood by laymen, the last quarter-century is seeing the wide application of ecology in environmental and human affairs, and this gives some assurance that the twenty-first century will not become one of chaos.

  4. The relative importance of rapid evolution for plant-microbe interactions depends on ecological context.

    Science.gov (United States)

    Terhorst, Casey P; Lennon, Jay T; Lau, Jennifer A

    2014-06-22

    Evolution can occur on ecological time-scales, affecting community and ecosystem processes. However, the importance of evolutionary change relative to ecological processes remains largely unknown. Here, we analyse data from a long-term experiment in which we allowed plant populations to evolve for three generations in dry or wet soils and used a reciprocal transplant to compare the ecological effect of drought and the effect of plant evolutionary responses to drought on soil microbial communities and nutrient availability. Plants that evolved under drought tended to support higher bacterial and fungal richness, and increased fungal : bacterial ratios in the soil. Overall, the magnitudes of ecological and evolutionary effects on microbial communities were similar; however, the strength and direction of these effects depended on the context in which they were measured. For example, plants that evolved in dry environments increased bacterial abundance in dry contemporary environments, but decreased bacterial abundance in wet contemporary environments. Our results suggest that interactions between recent evolutionary history and ecological context affect both the direction and magnitude of plant effects on soil microbes. Consequently, an eco-evolutionary perspective is required to fully understand plant-microbe interactions.

  5. Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy

    DEFF Research Database (Denmark)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H

    2017-01-01

    To target bacterial pathogens that invade and proliferate inside host cells, it is necessary to design intervention strategies directed against bacterial attachment, cellular invasion and intracellular proliferation. We present an automated microscopy-based, fast, high-throughput method for analy...

  6. Bacterial Communities in Women with Bacterial Vaginosis: High Resolution Phylogenetic Analyses Reveal Relationships of Microbiota to Clinical Criteria

    Science.gov (United States)

    Srinivasan, Sujatha; Hoffman, Noah G.; Morgan, Martin T.; Matsen, Frederick A.; Fiedler, Tina L.; Hall, Robert W.; Ross, Frederick J.; McCoy, Connor O.; Bumgarner, Roger; Marrazzo, Jeanne M.; Fredricks, David N.

    2012-01-01

    Background Bacterial vaginosis (BV) is a common condition that is associated with numerous adverse health outcomes and is characterized by poorly understood changes in the vaginal microbiota. We sought to describe the composition and diversity of the vaginal bacterial biota in women with BV using deep sequencing of the 16S rRNA gene coupled with species-level taxonomic identification. We investigated the associations between the presence of individual bacterial species and clinical diagnostic characteristics of BV. Methodology/Principal Findings Broad-range 16S rRNA gene PCR and pyrosequencing were performed on vaginal swabs from 220 women with and without BV. BV was assessed by Amsel’s clinical criteria and confirmed by Gram stain. Taxonomic classification was performed using phylogenetic placement tools that assigned 99% of query sequence reads to the species level. Women with BV had heterogeneous vaginal bacterial communities that were usually not dominated by a single taxon. In the absence of BV, vaginal bacterial communities were dominated by either Lactobacillus crispatus or Lactobacillus iners. Leptotrichia amnionii and Eggerthella sp. were the only two BV-associated bacteria (BVABs) significantly associated with each of the four Amsel’s criteria. Co-occurrence analysis revealed the presence of several sub-groups of BVABs suggesting metabolic co-dependencies. Greater abundance of several BVABs was observed in Black women without BV. Conclusions/Significance The human vaginal bacterial biota is heterogeneous and marked by greater species richness and diversity in women with BV; no species is universally present. Different bacterial species have different associations with the four clinical criteria, which may account for discrepancies often observed between Amsel and Nugent (Gram stain) diagnostic criteria. Several BVABs exhibited race-dependent prevalence when analyzed in separate groups by BV status which may contribute to increased incidence of BV in

  7. Linking human health, climate change, and food security through ecological-based sanitation systems

    Science.gov (United States)

    Ryals, R.; Kramer, S.; Porder, S.; Andersen, G. L.

    2015-12-01

    Ensuring access to clean, safe sanitation for the world's population remains a challenging, yet critical, global sustainability goal. Ecological-based sanitation (EcoSan) technology is a promising strategy for improving sanitation, particularly in areas where financial resources and infrastructure are limiting. The composting of human waste and its use as an agricultural soil amendment can tackle three important challenges in developing countries - providing improved sanitation for vulnerable communities, reducing the spread of intestinal-born pathogens, and returning nutrients and organic matter to degraded agricultural soils. The extent of these benefits and potential tradeoffs are not well known, but have important implications for the widespread adoption of this strategy to promote healthy communities and enhance food security. We quantified the effects of EcoSan on the climate and human health in partnership with Sustainable Organic Integrated Livelihoods (SOIL) in Haiti. We measured greenhouse gas emissions (nitrous oxide, methane, and carbon dioxide) from compost piles that ranged in age from 0 to 14 months (i.e. finished) from two compost facilities managed with or without cement lining. We also measured emissions from a government-operated waste treatment pond and a grass field where waste has been illegally dumped. The highest methane emissions were observed from the anaerobic waste pond, whereas the dump site and compost piles had higher nitrous oxide emissions. Net greenhouse gases (CO2-equivalents) from unlined compost piles were 8x lower than lined compost piles and 20 and 30x lower than the dump and waste pond, respectively. We screened finished compost for fecal pathogens using bacterial 16S sequencing. Bacterial pathogens were eliminated regardless of the type of composting process. Pilot trials indicate that the application of compost to crops has a large potential for increasing food production. This research suggests that EcoSan systems are

  8. Ecological impact assessment

    International Nuclear Information System (INIS)

    Thomas, J.M.; Eberhardt, L.L.

    1975-01-01

    Quantitative problems in accomplishing ecological impact assessment with particular reference to defining population effects are discussed with some comments on the two approaches most commonly used, e.g., the experimental and simulation models. Some alternatives are suggested because both methods will probably fail to detect real population effects mostly due to poor understanding of ecosystems or because of the limitations inherent in field census methods. Most judgments of ecological impact are not quantitatively defensible but are qualitative, subjective, or political in nature. An examination of aggregates of data from various nuclear power plant sites may be one way to obtain enough replication to judge ecological impact. Thus, currently available data from such studies as well as appropriate demographic, vegetation, census, and bibliographic material could offer an interesting challenge to computer professionals if such an undertaking were contemplated. Present research programs at PNL and computer involvement are described. Future possibilities and directions are discussed. (U.S.)

  9. Numerical ecology with R

    CERN Document Server

    Borcard, Daniel; Legendre, Pierre

    2018-01-01

    This new edition of Numerical Ecology with R guides readers through an applied exploration of the major methods of multivariate data analysis, as seen through the eyes of three ecologists. It provides a bridge between a textbook of numerical ecology and the implementation of this discipline in the R language. The book begins by examining some exploratory approaches. It proceeds logically with the construction of the key building blocks of most methods, i.e. association measures and matrices, and then submits example data to three families of approaches: clustering, ordination and canonical ordination. The last two chapters make use of these methods to explore important and contemporary issues in ecology: the analysis of spatial structures and of community diversity. The aims of methods thus range from descriptive to explanatory and predictive and encompass a wide variety of approaches that should provide readers with an extensive toolbox that can address a wide palette of questions arising in contemporary mul...

  10. Biodiversity in Benthic Ecology

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Carl, J. D.

    Foreword: This proceeding is based on a set of papers presented at the second Nordic Benthological Meeting held in Silkeborg, November 13-14, 1997. The main theme of the meeting was biodiversity in benthic ecology and the majority of contributions touch on this subject. In addition, the proceeding...... contains papers which cover other themes thus continuing with the spirit of the meetings in the Nordic Benthological Society (NORBS) by being an open forum for exchanging knowledge on all aspects of benthic ecology. Overall, we feel the proceeding contains a wide selection of very interesting papers...... representing the state-of-the-art of benthic ecology research within, and to a lesser degree, outside the Nordic countries. We wish to thank all the authors for their inspirational contributions to the proceeding, but we feel that a special thanks is due to the invited speakers for their readiness to produce...

  11. Application of ecological mapping

    International Nuclear Information System (INIS)

    Sherk, J.A.

    1982-01-01

    The US Fish and Wildlife Service has initiated the production of a comprehensive ecological inventory map series for use as a major new planning tool. Important species data along with special land use designations are displayed on 1:250,000 scale topographic base maps. Sets of maps have been published for the Atlantic and Pacific coastal areas of the United States. Preparation of a map set for the Gulf of Mexico is underway at the present time. Potential application of ecological inventory map series information to a typical land disposal facility could occur during the narrowing of the number of possible disposal sites, the design of potential disposal site studies of ecological resources, the preparation of the environmental report, and the regulatory review of license applications. 3 figures, 3 tables

  12. Ecological Perspectives in HCI

    DEFF Research Database (Denmark)

    Blevis, Eli; Bødker, Susanne; Flach, John

    The aim of the workshop is to provide a forum for researchers and practitioners to discuss the present and future of ecological perspectives in HCI. The participants will reflect on the current uses and interpretations of “ecology” and related concepts in the field. The workshop will assess the p...... the potential of ecological perspectives in HCI for supporting rich and meaningful analysis, as well as innovative design, of interactive technologies in real-life contexts......The aim of the workshop is to provide a forum for researchers and practitioners to discuss the present and future of ecological perspectives in HCI. The participants will reflect on the current uses and interpretations of “ecology” and related concepts in the field. The workshop will assess...

  13. Coevolutionary ecological economics

    Energy Technology Data Exchange (ETDEWEB)

    Kallis, Giorgos [ICREA Researcher, ICTA, Universidad Autonoma de Barcelona, ETSE, QC/3095, 08193 Bellatera, Barcelona (Spain); Norgaard, Richard B. [Energy and Resources Group, University of California at Berkeley, 310 Barrows Hall, Berkeley, CA, 94720-3050 (United States)

    2010-02-15

    This paper maps a coevolutionary research agenda for ecological economics. At an epistemological level coevolution offers a powerful logic for transcending environmental and social determinisms and developing a cross-disciplinary approach in the study of socio-ecological systems. We identify four consistent stories emerging out of coevolutionary studies in ecological economics, concerning: environmental degradation and development failure in peripheral regions; the lock-in of unsustainable production-consumption patterns; the vicious cycle between human efforts to control undesirable micro-organisms and the evolution of these organisms; and the adaptive advantages of other-regarding, cooperative behaviors and institutions. We identify challenges in the conceptualization of coevolutionary relationships in relation to: the interaction between different hierarchical levels of evolution; the role of space and social power; uneven rates of change and crises. We conclude with the political implications of a coevolutionary perspective based on the premises of pragmatism. (author)

  14. Corruption of innate immunity by bacterial proteases.

    Science.gov (United States)

    Potempa, Jan; Pike, Robert N

    2009-01-01

    The innate immune system of the human body has developed numerous mechanisms to control endogenous and exogenous bacteria and thus prevent infections by these microorganisms. These mechanisms range from physical barriers such as the skin or mucosal epithelium to a sophisticated array of molecules and cells that function to suppress or prevent bacterial infection. Many bacteria express a variety of proteases, ranging from non-specific and powerful enzymes that degrade many proteins involved in innate immunity to proteases that are extremely precise and specific in their mode of action. Here we have assembled a comprehensive picture of how bacterial proteases affect the host's innate immune system to gain advantage and cause infection. This picture is far from being complete since the numbers of mechanisms utilized are as astonishing as they are diverse, ranging from degradation of molecules vital to innate immune mechanisms to subversion of the mechanisms to allow the bacterium to hide from the system or take advantage of it. It is vital that such mechanisms are elucidated to allow strategies to be developed to aid the innate immune system in controlling bacterial infections.

  15. Diagnosis and treatment of bacterial meningitis in the newborn ...

    African Journals Online (AJOL)

    Background: Bacterial meningitis in the newborn is globally renowned for high mortality. The associated morbidities also include audiologic, motor, visual and mental deficits. Objective: To highlight the peculiarities in the current diagnostic and management strategies in newborn meningitis. Methods: Relevant literature on ...

  16. Dynamics of germs responsible for acute bacterial meningitis in ...

    African Journals Online (AJOL)

    The aim of this study was to analyze ten (10) years of epidemiological surveillance data of meningitis in Burkina Faso for high risk germs patterns identification in order to contribute to the strengthening of prevention strategies. A retrospective study of the past decade (2005- 2014) of cases of acute bacterial meningitis ...

  17. Pyramiding of blast and bacterial leaf blight resistance genes into ...

    African Journals Online (AJOL)

    Blast caused by the fungus Magnaporthe oryzae (Hebert) Barr. and bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) are two major diseases of rice (Oryza sativa). The use of varietal resistance is the most appropriate strategy for controlling the diseases, and molecular assisted selection can ...

  18. 10 original article dynamics of germs responsible for acute bacterial ...

    African Journals Online (AJOL)

    boaz

    The aim of this study was to analyze ten (10) years of epidemiological surveillance data of meningitis in Burkina Faso for high risk germs patterns identification in order to contribute to the strengthening of prevention strategies. A retrospective study of the past decade (2005- 2014) of cases of acute bacterial meningitis ...

  19. Gut microbiota role in irritable bowel syndrome: New therapeutic strategies.

    Science.gov (United States)

    Distrutti, Eleonora; Monaldi, Lorenzo; Ricci, Patrizia; Fiorucci, Stefano

    2016-02-21

    In the last decade the impressive expansion of our knowledge of the vast microbial community that resides in the human intestine, the gut microbiota, has provided support to the concept that a disturbed intestinal ecology might promote development and maintenance of symptoms in irritable bowel syndrome (IBS). As a correlate, manipulation of gut microbiota represents a new strategy for the treatment of this multifactorial disease. A number of attempts have been made to modulate the gut bacterial composition, following the idea that expansion of bacterial species considered as beneficial (Lactobacilli and Bifidobacteria) associated with the reduction of those considered harmful (Clostridium, Escherichia coli, Salmonella, Shigella and Pseudomonas) should attenuate IBS symptoms. In this conceptual framework, probiotics appear an attractive option in terms of both efficacy and safety, while prebiotics, synbiotics and antibiotics still need confirmation. Fecal transplant is an old treatment translated from the cure of intestinal infective pathologies that has recently gained a new life as therapeutic option for those patients with a disturbed gut ecosystem, but data on IBS are scanty and randomized, placebo-controlled studies are required.

  20. Bacterial polyhydroxyalkanoates: Still fabulous?

    Science.gov (United States)

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. Energetics of bacterial adhesion

    International Nuclear Information System (INIS)

    Loosdrecht, M.C.M. van; Zehnder, A.J.B.

    1990-01-01

    For the description of bacterial adhesion phenomena two different physico-chemical approaches are available. The first one, based on a surface Gibbs energy balance, assumes intimate contact between the interacting surfaces. The second approach, based on colloid chemical theories (DLVO theory), allows for two types of adhesion: 1) secondary minimum adhesion, which is often weak and reversible, and 2) irreversible primary minimum adhesion. In the secondary minimum adhesion a thin water film remains present between the interacting surface. The merits of both approaches are discussed in this paper. In addition, the methods available to measure the physico-chemical surface characteristics of bacteria and the influence of adsorbing (in)organic compounds, extracellular polymers and cell surface appendages on adhesion are summarized. (author) 2 figs., 1 tab., 50 refs

  2. Biosensors of bacterial cells.

    Science.gov (United States)

    Burlage, Robert S; Tillmann, Joshua

    2017-07-01

    Biosensors are devices which utilize both an electrical component (transducer) and a biological component to study an environment. They are typically used to examine biological structures, organisms and processes. The field of biosensors has now become so large and varied that the technology can often seem impenetrable. Yet the principles which underlie the technology are uncomplicated, even if the details of the mechanisms are elusive. In this review we confine our analysis to relatively current advancements in biosensors for the detection of whole bacterial cells. This includes biosensors which rely on an added labeled component and biosensors which do not have a labeled component and instead detect the binding event or bound structure on the transducer. Methods to concentrate the bacteria prior to biosensor analysis are also described. The variety of biosensor types and their actual and potential uses are described. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome.......Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par...

  4. Anaerobes in bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Aggarwal A

    2003-01-01

    Full Text Available Four hundred high vaginal swabs were taken from patients attending gynaecology and obstetrics department of Govt. medical college, Amritsar. The patients were divided into four groups i.e. women in pregnancy (Group I, in labour/post partum (Group II, with abnormal vaginal discharge or bacterial vaginosis (Group III and asymptomatic women as control (Group IV. Anaerobic culture of vaginal swabs revealed that out of 400 cases, 212(53% were culture positive. Maximum isolation of anaerobes was in group III (84% followed by group II (56%, group I (36% and control group (15%. Gram positive anaerobes (69.2% out numbered gram negatives (30.8%. Among various isolates Peptostreptococcus spp. and Bacteroides spp. were predominant.

  5. Salient Ecological Sensitive Regions of Central Western Ghats, India

    Science.gov (United States)

    Ramachandra, T. V.; Bharath, Setturu; Subash Chandran, M. D.; Joshi, N. V.

    2018-02-01

    Ecologically sensitive regions (ESRs) are the `ecological units' with the exceptional biotic and abiotic elements. Identification of ESRs considering spatially both ecological and social dimensions of environmental variables helps in ecological and conservation planning as per Biodiversity Act, 2002, Government of India. The current research attempts to integrate ecological and environmental considerations into administration, and prioritizes regions at Panchayat levels (local administrative unit) in Uttara Kannada district, Central Western Ghats, Karnataka state considering attributes (biological, Geo-climatic, Social, etc.) as ESR (1-4) through weightage score metrics. The region has the distinction of having highest forest area (80.48%) in Karnataka State, India and has been undergoing severe anthropogenic pressures impacting biogeochemistry, hydrology, food security, climate and socio-economic systems. Prioritisation of ESRs helps in the implementation of the sustainable developmental framework with the appropriate conservation strategies through the involvement of local stakeholders.

  6. Salient Ecological Sensitive Regions of Central Western Ghats, India

    Science.gov (United States)

    Ramachandra, T. V.; Bharath, Setturu; Subash Chandran, M. D.; Joshi, N. V.

    2018-05-01

    Ecologically sensitive regions (ESRs) are the `ecological units' with the exceptional biotic and abiotic elements. Identification of ESRs considering spatially both ecological and social dimensions of environmental variables helps in ecological and conservation planning as per Biodiversity Act, 2002, Government of India. The current research attempts to integrate ecological and environmental considerations into administration, and prioritizes regions at Panchayat levels (local administrative unit) in Uttara Kannada district, Central Western Ghats, Karnataka state considering attributes (biological, Geo-climatic, Social, etc.) as ESR (1-4) through weightage score metrics. The region has the distinction of having highest forest area (80.48%) in Karnataka State, India and has been undergoing severe anthropogenic pressures impacting biogeochemistry, hydrology, food security, climate and socio-economic systems. Prioritisation of ESRs helps in the implementation of the sustainable developmental framework with the appropriate conservation strategies through the involvement of local stakeholders.

  7. Bioreporters in microbial ecology

    NARCIS (Netherlands)

    Leveau, J.H.J.; Lindow, S.E.

    2002-01-01

    Bioreporters are effective research tools for gaining an understanding of a microbe's perception of the world. Fitted with a fusion of an environmentally responsive promoter to a suitable reporter gene, a bacterial or fungal bioreporter is able to communicate its metabolic or transcriptional

  8. Art, Ecology and Institutions

    DEFF Research Database (Denmark)

    Witzke, Anne Sophie

    2013-01-01

    The discourse of ecology and sustainability has gained critical traction in recent years. But how are these concepts framed within the space, language and idea of the exhibition? This panel discussion, moderated by Steven Lam and conducted by email in July 2012, sought to unpack the claims...... and limits of the ecological, looking specifically at various international case studies, within the practice of curatorial and exhibition studies. The discussion begins with a reflection on ‘DON'T/PANIC’ in Durban and ‘Rethink – Contemporary Art and Climate Change’ in Copenhagen, exhibitions that were...

  9. Ecology of gelatious plankton

    DEFF Research Database (Denmark)

    Jaspers, Cornelia

    as a result of this invasion and its ecological and economic impacts. In 2005, when M. leidyi was sighted in Northern Europe for the first time, similar consequences were feared. The aim of my PhD project was to understand the potential impact of M. leidyi on the Baltic Sea ecosystem and constrains on its...... in high and intermediate saline areas in Northern Europe. While the ecological impact of M. leidyi in the central Baltic appears to be limited concern, the environment in other European waters should be more favourable to their populations. In these areas, it is suggested that M. leidyi constitutes...

  10. Properties of bacterial endophytes and their proposed role in plant growth

    NARCIS (Netherlands)

    Hardoim, P.R.; Overbeek, van L.S.; Elsas, van J.D.

    2008-01-01

    Bacterial endophytes live inside plants for at least part of their life cycle. Studies of the interaction of endophytes with their host plants and their function within their hosts are important to address the ecological relevance of endophytes. The modulation of ethylene levels in plants by

  11. Functional diversity and redundancy across fish gut, sediment and water bacterial communities.

    Science.gov (United States)

    Escalas, Arthur; Troussellier, Marc; Yuan, Tong; Bouvier, Thierry; Bouvier, Corinne; Mouchet, Maud A; Flores Hernandez, Domingo; Ramos Miranda, Julia; Zhou, Jizhong; Mouillot, David

    2017-08-01

    This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (β) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Ecological restoration alters microbial communities in mine tailings profiles.

    Science.gov (United States)

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-04-29

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0-30 cm soils and altered the bacterial communities at 0-20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30-60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0-20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings.

  13. Vibrio trends in the ecology of the Venice lagoon.

    Science.gov (United States)

    Rahman, Mohammad Shamsur; Martino, Maria Elena; Cardazzo, Barbara; Facco, Pierantonio; Bordin, Paola; Mioni, Renzo; Novelli, Enrico; Fasolato, Luca

    2014-04-01

    Vibrio is a very diverse genus that is responsible for different human and animal diseases. The accurate identification of Vibrio at the species level is important to assess the risks related to public health and diseases caused by aquatic organisms. The ecology of Vibrio spp., together with their genetic background, represents an important key for species discrimination and evolution. Thus, analyses of population structure and ecology association are necessary for reliable characterization of bacteria and to investigate whether bacterial species are going through adaptation processes. In this study, a population of Vibrionaceae was isolated from shellfish of the Venice lagoon and analyzed in depth to study its structure and distribution in the environment. A multilocus sequence analysis (MLSA) was developed on the basis of four housekeeping genes. Both molecular and biochemical approaches were used for species characterization, and the results were compared to assess the consistency of the two methods. In addition, strain ecology and the association between genetic information and environment were investigated through statistical models. The phylogenetic and population analyses achieved good species clustering, while biochemical identification was demonstrated to be imprecise. In addition, this study provided a fine-scale overview of the distribution of Vibrio spp. in the Venice lagoon, and the results highlighted a preferential association of the species toward specific ecological variables. These findings support the use of MLSA for taxonomic studies and demonstrate the need to consider environmental information to obtain broader and more accurate bacterial characterization.

  14. Ecological restoration alters microbial communities in mine tailings profiles

    Science.gov (United States)

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-04-01

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0-30 cm soils and altered the bacterial communities at 0-20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30-60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0-20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings.

  15. Beyond positivist ecology: toward an integrated ecological ethics.

    Science.gov (United States)

    Norton, Bryan G

    2008-12-01

    A post-positivist understanding of ecological science and the call for an "ecological ethic" indicate the need for a radically new approach to evaluating environmental change. The positivist view of science cannot capture the essence of environmental sciences because the recent work of "reflexive" ecological modelers shows that this requires a reconceptualization of the way in which values and ecological models interact in scientific process. Reflexive modelers are ecological modelers who believe it is appropriate for ecologists to examine the motives for their choices in developing models; this self-reflexive approach opens the door to a new way of integrating values into public discourse and to a more comprehensive approach to evaluating ecological change. This reflexive building of ecological models is introduced through the transformative simile of Aldo Leopold, which shows that learning to "think like a mountain" involves a shift in both ecological modeling and in values and responsibility. An adequate, interdisciplinary approach to ecological valuation, requires a re-framing of the evaluation questions in entirely new ways, i.e., a review of the current status of interdisciplinary value theory with respect to ecological values reveals that neither of the widely accepted theories of environmental value-neither economic utilitarianism nor intrinsic value theory (environmental ethics)-provides a foundation for an ecologically sensitive evaluation process. Thus, a new, ecologically sensitive, and more comprehensive approach to evaluating ecological change would include an examination of the metaphors that motivate the models used to describe environmental change.

  16. Recent advances in primate nutritional ecology.

    Science.gov (United States)

    Righini, Nicoletta

    2017-04-01

    Nutritional ecology seeks to explain, in an ecological and evolutionary context, how individuals choose, acquire, and process food to satisfy their nutritional requirements. Historically, studies of primate feeding ecology have focused on characterizing diets in terms of the botanical composition of the plants consumed. Further, dietary studies have demonstrated how patch and food choice in relation to time spent foraging and feeding are influenced by the spatial and temporal distribution of resources and by social factors such as feeding competition, dominance, or partner preferences. From a nutritional perspective, several theories including energy and protein-to-fiber maximization, nutrient mixing, and toxin avoidance, have been proposed to explain the food choices of non-human primates. However, more recently, analytical frameworks such as nutritional geometry have been incorporated into primatology to explore, using a multivariate approach, the synergistic effects of multiple nutrients, secondary metabolites, and energy requirements on primate food choice. Dietary strategies associated with nutrient balancing highlight the tradeoffs that primates face in bypassing or selecting particular feeding sites and food items. In this Special Issue, the authors bring together a set of studies focusing on the nutritional ecology of a diverse set of primate taxa characterized by marked differences in dietary emphasis. The authors present, compare, and discuss the diversity of strategies used by primates in diet selection, and how species differences in ecology, physiology, anatomy, and phylogeny can affect patterns of nutrient choice and nutrient balancing. The use of a nutritionally explicit analytical framework is fundamental to identify the nutritional requirements of different individuals of a given species, and through its application, direct conservation efforts can be applied to regenerate and protect specific foods and food patches that offer the opportunity of a

  17. Bacterial meningitis in immunocompromised patients

    NARCIS (Netherlands)

    van Veen, K.E.B.

    2018-01-01

    Bacterial meningitis is an acute infection of the meninges, in The Netherlands most commonly caused by Streptococcus pneumoniae and Neisseria meningitides. Risk factors for acquiring bacterial meningitis include a decreased function of the immune system. The aim of this thesis was to study

  18. Bacteriële meningitis

    NARCIS (Netherlands)

    Brouwer, M. C.; van de Beek, D.

    2012-01-01

    Bacterial meningitis is a severe disease which affects 35.000 Europeans each year and has a mortality rate of about 20%. During the past 25 years the epidemiology of bacterial meningitis has changed significantly due to the implementation of vaccination against Haemophilus influenzae, Neisseria

  19. Energy policies in the European Union. Germany's ecological tax reform

    International Nuclear Information System (INIS)

    Welfens, P.J.J.; Jungmittag, A.; Meyer, B.; Jasinski, P.

    2001-01-01

    The chapters discuss the following aspects: 1. Energy policy as a strategic element of economic policy in dynamic open economies. 2. Phasing out nuclear energy and core elements of sustainable energy strategy. 3. Ecological tax reform: Theory, modified double dividend and international aspects. 4. The policy framework in Europe and Germany. 5. Optimal ecological tax reform: Options and recommendations for an EU-action plan. 6. Conclusions. (orig./CB)

  20. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten

    2010-01-01

    in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by tyrosine......Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  1. Bacterial Artificial Chromosome Mutagenesis Using Recombineering

    Directory of Open Access Journals (Sweden)

    Kumaran Narayanan

    2011-01-01

    Full Text Available Gene expression from bacterial artificial chromosome (BAC clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough to transfer intact genes in their native chromosomal setting together with flanking regulatory elements to provide all the signals for correct spatiotemporal gene expression. Until recently, the use of BACs for functional studies has been limited because their large size has inherently presented a major obstacle for introducing modifications using conventional genetic engineering strategies. The development of in vivo homologous recombination strategies based on recombineering in E. coli has helped resolve this problem by enabling facile engineering of high molecular weight BAC DNA without dependence on suitably placed restriction enzymes or cloning steps. These techniques have considerably expanded the possibilities for studying functional genetics using BACs in vitro and in vivo.

  2. Ecological principles relevant to nuclear war

    International Nuclear Information System (INIS)

    Hutchinson, T.C.; Cropper, W.P. Jr.; Grover, H.D.

    1985-01-01

    The ecological principles outlined are very basic ones; the authors anticipate a readership trained in a broad range of disciplines, including those unfamiliar with the academic discipline of ecology. The authors include substantial discussion on ecophysiology (i.e., the responses of organisms to their environment) because this is relevant to the new understanding of the potential climatic consequences of nuclear war. In particular, the physiological sensitivity of organisms to reduced levels of light and temperature are a key part of the analysis of the potential ecological effects and agricultural effects of nuclear war. Much of the ecological analysis has been organized around major biological units called biomes. The authors describe the biome concept and discuss some of the environmental-climatic factors that are believed to control biome distribution. Emphasis is given to plants because of their controlling influence on ecosystem functions through their role as primary producers. Future reports are needed to address more fully the potential effects on animals. Much more research needs to be done on both plant and animal responses to the types of perturbations possible for the aftermath of a nuclear war. Another important element for analysis of the potential ecological consequences of nuclear war concerns recovery processes. As the post-nuclear war environmental extremes ameliorate, ecological communities in devastated regions would begin to reorganize. It is not possible to predict the course of such a succession precisely, but some principles concerning post-perturbation replacement (such as seed banks and germination), relevant successional patterns, and organism strategies are discussed

  3. Phosphorus physiological ecology and molecular mechanisms in marine phytoplankton.

    Science.gov (United States)

    Lin, Senjie; Litaker, Richard Wayne; Sunda, William G

    2016-02-01

    Phosphorus (P) is an essential nutrient for marine phytoplankton and indeed all life forms. Current data show that P availability is growth-limiting in certain marine systems and can impact algal species composition. Available P occurs in marine waters as dissolved inorganic phosphate (primarily orthophosphate [Pi]) or as a myriad of dissolved organic phosphorus (DOP) compounds. Despite numerous studies on P physiology and ecology and increasing research on genomics in marine phytoplankton, there have been few attempts to synthesize information from these different disciplines. This paper is aimed to integrate the physiological and molecular information on the acquisition, utilization, and storage of P in marine phytoplankton and the strategies used by these organisms to acclimate and adapt to variations in P availability. Where applicable, we attempt to identify gaps in our current knowledge that warrant further research and examine possible metabolic pathways that might occur in phytoplankton from well-studied bacterial models. Physical and chemical limitations governing cellular P uptake are explored along with physiological and molecular mechanisms to adapt and acclimate to temporally and spatially varying P nutrient regimes. Topics covered include cellular Pi uptake and feedback regulation of uptake systems, enzymatic utilization of DOP, P acquisition by phagotrophy, P-limitation of phytoplankton growth in oceanic and coastal waters, and the role of P-limitation in regulating cell size and toxin levels in phytoplankton. Finally, we examine the role of P and other nutrients in the transition of phytoplankton communities from early succession species (diatoms) to late succession ones (e.g., dinoflagellates and haptophytes). © 2015 Phycological Society of America.

  4. Ecology in Urban Education.

    Science.gov (United States)

    Johnson, Letitia K.; Ryan, Michael

    In this course guide to the teaching of urban ecology, six learning activities on the following topics are outlined: (1) city location and growth; (2) an in-depth study of New Orleans; (3) city shape and structure; (4) size and spacing of cities; (5) cities with special functions; (6) local community study. Educational objectives for each activity…

  5. Ecological aspects of parasitology

    National Research Council Canada - National Science Library

    Kennedy, Clive Russell

    1976-01-01

    ... of these habitats that enable them to cope with and overcome these difficulties. The third section is concerned with population ecology, and emphasises that although individual parasites have to face and overcome particular problems, parasitism is essentially a dynamic relationship between two species populations.

  6. Complexity and ecology

    International Nuclear Information System (INIS)

    Gomez Giraldo, Luis Jair

    2002-01-01

    The present article examines the transformation that the construction of the theoretical body of ecology as a science has been going through since it first appeared in the XIX century within the logic of classical science until recent developments comprised within complex systemic. Mainly departing from the analysis from thermodynamics of irreversible phenomena

  7. The Autoimmune Ecology.

    Science.gov (United States)

    Anaya, Juan-Manuel; Ramirez-Santana, Carolina; Alzate, Maria A; Molano-Gonzalez, Nicolas; Rojas-Villarraga, Adriana

    2016-01-01

    Autoimmune diseases (ADs) represent a heterogeneous group of disorders that affect specific target organs or multiple organ systems. These conditions share common immunopathogenic mechanisms (i.e., the autoimmune tautology), which explain the clinical similarities they have among them as well as their familial clustering (i.e., coaggregation). As part of the autoimmune tautology, the influence of environmental exposure on the risk of developing ADs is paramount (i.e., the autoimmune ecology). In fact, environment, more than genetics, shapes immune system. Autoimmune ecology is akin to exposome, that is all the exposures - internal and external - across the lifespan, interacting with hereditary factors (both genetics and epigenetics) to favor or protect against autoimmunity and its outcomes. Herein, we provide an overview of the autoimmune ecology, focusing on the immune response to environmental agents in general, and microbiota, cigarette smoking, alcohol and coffee consumption, socioeconomic status (SES), gender and sex hormones, vitamin D, organic solvents, and vaccines in particular. Inclusion of the autoimmune ecology in disease etiology and health will improve the way personalized medicine is currently conceived and applied.

  8. Ecology, recreation and landscape

    Energy Technology Data Exchange (ETDEWEB)

    Satchell, J E

    1983-01-01

    The article is dedicated to the problems of combining mass tourism in certain countries of Western Europe and environmental protection (OOS) requirements. The ecological damage from recreation is examined and the throughput of the medium is evaluated. The author proposes development of regulable, managable and controllable recreation use of natural resources and landscapes using selective advertising of the recreation sites.

  9. Ecological Interface Design

    DEFF Research Database (Denmark)

    Vicente, Kim J.; Rasmussen, Jens

    1992-01-01

    A theoretical framework for designing interfaces for complex human-machine systems is proposed. The framework, called ecological interface design (EID), is based on the skills, rules, knowledge taxonomy of cognitive control. The basic goal of EID is twofold: first, not to force processing...

  10. Molecular microbial ecology manual

    NARCIS (Netherlands)

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

    2004-01-01

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

  11. Ecology and Human Destiny.

    Science.gov (United States)

    Haught, John F.

    1999-01-01

    Examines eschatology as the heart of Christian faith, suggesting that an appreciation of an eschatological interpretation of the cosmos enables acceptance of nature's transience and a grounding for an ecological ethic. Maintains that recent scientific developments present a promising, rather than pessimistic, picture of the universe. Holds that…

  12. Urban Sound Ecologies

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh; Samson, Kristine

    2013-01-01

    . The article concludes that the ways in which recent sound installations work with urban ecologies vary. While two of the examples blend into the urban environment, the other transfers the concert format and its mode of listening to urban space. Last, and in accordance with recent soundscape research, we point...

  13. Metabolomics in chemical ecology.

    Science.gov (United States)

    Kuhlisch, Constanze; Pohnert, Georg

    2015-07-01

    Chemical ecology elucidates the nature and role of natural products as mediators of organismal interactions. The emerging techniques that can be summarized under the concept of metabolomics provide new opportunities to study such environmentally relevant signaling molecules. Especially comparative tools in metabolomics enable the identification of compounds that are regulated during interaction situations and that might play a role as e.g. pheromones, allelochemicals or in induced and activated defenses. This approach helps overcoming limitations of traditional bioassay-guided structure elucidation approaches. But the power of metabolomics is not limited to the comparison of metabolic profiles of interacting partners. Especially the link to other -omics techniques helps to unravel not only the compounds in question but the entire biosynthetic and genetic re-wiring, required for an ecological response. This review comprehensively highlights successful applications of metabolomics in chemical ecology and discusses existing limitations of these novel techniques. It focuses on recent developments in comparative metabolomics and discusses the use of metabolomics in the systems biology of organismal interactions. It also outlines the potential of large metabolomics initiatives for model organisms in the field of chemical ecology.

  14. Ecology under lake ice

    NARCIS (Netherlands)

    Hampton, Stephanie E.; Galloway, Aaron W. E.; Powers, Stephen M.; Ozersky, Ted; Woo, Kara H.; Batt, Ryan D.; Labou, Stephanie G.; O'Reilly, Catherine M.; Sharma, Sapna; Lottig, Noah R.; Stanley, Emily H.; North, Rebecca L.; Stockwell, Jason D.; Adrian, Rita; Weyhenmeyer, Gesa A.; Arvola, Lauri; Baulch, Helen M.; Bertani, Isabella; Bowman, Larry L., Jr.; Carey, Cayelan C.; Catalan, Jordi; Colom-Montero, William; Domine, Leah M.; Felip, Marisol; Granados, Ignacio; Gries, Corinna; Grossart, Hans-Peter; Haberman, Juta; Haldna, Marina; Hayden, Brian; Higgins, Scott N.; Jolley, Jeff C.; Kahilainen, Kimmo K.; Kaup, Enn; Kehoe, Michael J.; MacIntyre, Sally; Mackay, Anson W.; Mariash, Heather L.; Mckay, Robert M.; Nixdorf, Brigitte; Noges, Peeter; Noges, Tiina; Palmer, Michelle; Pierson, Don C.; Post, David M.; Pruett, Matthew J.; Rautio, Milla; Read, Jordan S.; Roberts, Sarah L.; Ruecker, Jacqueline; Sadro, Steven; Silow, Eugene A.; Smith, Derek E.; Sterner, Robert W.; Swann, George E. A.; Timofeyev, Maxim A.; Toro, Manuel; Twiss, Michael R.; Vogt, Richard J.; Watson, Susan B.; Whiteford, Erika J.; Xenopoulos, Marguerite A.

    Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experi-ence periods of snow and ice cover. Relatively little is known of winter ecology in these systems,due to a historical research focus on summer ‘growing seasons’. We executed the first global

  15. THE AUTOIMMUNE ECOLOGY.

    Directory of Open Access Journals (Sweden)

    Juan-Manuel eAnaya

    2016-04-01

    Full Text Available Autoimmune diseases (ADs represent a heterogeneous group of disorders that affect specific target organs or multiple organ systems. These conditions share common immunopathogenic mechanisms (i.e., the autoimmune tautology, which explain the clinical similarities they have among them as well as their familial clustering (i.e., coaggregation. As part of the autoimmune tautology, the influence of environmental exposure on the risk of developing ADs is paramount (i.e., the autoimmune ecology. In fact, environment, more than genetics, shapes immune system. Autoimmune ecology is akin to exposome, that is all the exposures - internal and external - across the lifespan, interacting with hereditary factors (both genetics and epigenetics to favor or protect against autoimmunity and its outcomes. Herein we provide an overview of the autoimmune ecology, focusing on the immune response to environmental agents in general, and microbiota, cigarette smoking, alcohol and coffee consumption, socioeconomic status, gender and sex hormones, vitamin D, organic solvents and vaccines in particular. Inclusion of the autoimmune ecology in disease etiology and health will improve the way personalized medicine is currently conceived and applied.

  16. Autogenic succession and deterministic recovery following disturbance in soil bacterial communities

    DEFF Research Database (Denmark)

    Jurburg, Stephanie D.; Nunes, Ines Marques; Stegen, James C.

    2017-01-01

    The response of bacterial communities to environmental change may affect local to global nutrient cycles. However the dynamics of these communities following disturbance are poorly understood, given that they are often evaluated over macro-ecological time scales and end-point measurements. In ord...... diversity and functional redundancy, respond to disturbances like many macro-ecological systems and exhibit path-dependent, autogenic dynamics during secondary succession. These results highlight the role of autogenic factors and successional dynamics in microbial recovery....... to understand the successional trajectory of soil bacterial communities following disturbances and the mechanisms controlling these dynamics at a scale relevant for these organisms, we subjected soil microcosms to a heat disturbance and followed the community composition of active bacteria over 50 days...... slowed down, and a stability phase (after 29 days), during which the community tended towards its original composition. Phylogenetic turnover patterns indicated that the community experienced stronger deterministic selection during recovery. Thus, soil bacterial communities, despite their extreme...

  17. Modeling physiological resistance in bacterial biofilms.

    Science.gov (United States)

    Cogan, N G; Cortez, Ricardo; Fauci, Lisa

    2005-07-01

    A mathematical model of the action of antimicrobial agents on bacterial biofilms is presented. The model includes the fluid dynamics in and around the biofilm, advective and diffusive transport of two chemical constituents and the mechanism of physiological resistance. Although the mathematical model applies in three dimensions, we present two-dimensional simulations for arbitrary biofilm domains and various dosing strategies. The model allows the prediction of the spatial evolution of bacterial population and chemical constituents as well as different dosing strategies based on the fluid motion. We find that the interaction between the nutrient and the antimicrobial agent can reproduce survival curves which are comparable to other model predictions as well as experimental results. The model predicts that exposing the biofilm to low concentration doses of antimicrobial agent for longer time is more effective than short time dosing with high antimicrobial agent concentration. The effects of flow reversal and the roughness of the fluid/biofilm are also investigated. We find that reversing the flow increases the effectiveness of dosing. In addition, we show that overall survival decreases with increasing surface roughness.

  18. Valuation of ecological resources

    Energy Technology Data Exchange (ETDEWEB)

    Scott, M.J.; Bilyard, G.R.; Link, S.O.; Ricci, P.F.; Seely, H.E.; Ulibarri, C.A.; Westerdahl, H.E.

    1995-04-01

    Ecological resources are resources that have functional value to ecosystems. Frequently, these functions are overlooked in terms of the value they provide to humans. Environmental economics is in search of an appropriate analysis framework for such resources. In such a framework, it is essential to distinguish between two related subsets of information: (1) ecological processes that have intrinsic value to natural ecosystems; and (2) ecological functions that are values by humans. The present study addresses these concerns by identifying a habitat that is being displaced by development, and by measuring the human and ecological values associated with the ecological resources in that habitat. It is also essential to determine which functions are mutually exclusive and which are, in effect, complementary or products of joint production. The authors apply several resource valuation tools, including contingent valuation methodology (CVM), travel cost methodology (TCM), and hedonic damage-pricing (HDP). One way to derive upper-limit values for more difficult-to-value functions is through the use of human analogs, because human-engineered systems are relatively inefficient at supplying the desired services when compared with natural systems. Where data on the relative efficiencies of natural systems and human analogs exist, it is possible to adjust the costs of providing the human analog by the relative efficiency of the natural system to obtain a more realistic value of the function under consideration. The authors demonstrate this approach in an environmental economic case study of the environmental services rendered by shrub-steppe habitats of Benton County, Washington State.

  19. Bacterial disease management: challenges, experience, innovation and future prospects: Challenges in Bacterial Molecular Plant Pathology.

    Science.gov (United States)

    Sundin, George W; Castiblanco, Luisa F; Yuan, Xiaochen; Zeng, Quan; Yang, Ching-Hong

    2016-12-01

    only identify optimal targets in the pathogens, but also optimal seasonal timings for deployment. Host resistance to effectors must be exploited, carefully and correctly. Are there other candidate genes that could be targeted in transgenic approaches? How can new technologies (CRISPR, TALEN, etc.) be most effectively used to add sustainable disease resistance to existing commercially desirable plant cultivars? We need an insider's perspective on the management of systemic pathogens. In addition to host resistance or reduced sensitivity, are there other methods that can be used to target these pathogen groups? Biological systems are variable. Can biological control strategies be improved for bacterial disease management and be made more predictable in function? The answers to the research foci outlined above are not all available, as will become apparent in this article, but we are heading in the right direction. In this article, we summarize the contributions from past experiences in bacterial disease management, and also describe how advances in bacterial genetics, genomics and host-pathogen interactions are informing novel strategies in virulence inhibition and in host resistance. We also outline potential innovations that could be exploited as the pressures to maximize a safe and productive food supply continue to become more numerous and more complex. © 2016 BSPP and John Wiley & Sons Ltd.

  20. Genus-wide comparison of Pseudovibrio bacterial genomes reveal diverse adaptations to different marine invertebrate hosts.

    Science.gov (United States)

    Alex, Anoop; Antunes, Agostinho

    2018-01-01

    Bacteria belonging to the genus Pseudovibrio have been frequently found in association with a wide variety of marine eukaryotic invertebrate hosts, indicative of their versatile and symbiotic lifestyle. A recent comparison of the sponge-associated Pseudovibrio genomes has shed light on the mechanisms influencing a successful symbiotic association with sponges. In contrast, the genomic architecture of Pseudovibrio bacteria associated with other marine hosts has received less attention. Here, we performed genus-wide comparative analyses of 18 Pseudovibrio isolated from sponges, coral, tunicates, flatworm, and seawater. The analyses revealed a certain degree of commonality among the majority of sponge- and coral-associated bacteria. Isolates from other marine invertebrate host, tunicates, exhibited a genetic repertoire for cold adaptation and specific metabolic abilities including mucin degradation in the Antarctic tunicate-associated bacterium Pseudovibrio sp. Tun.PHSC04_5.I4. Reductive genome evolution was simultaneously detected in the flatworm-associated bacteria and the sponge-associated bacterium P. axinellae AD2, through the loss of major secretion systems (type III/VI) and virulence/symbioses factors such as proteins involved in adhesion and attachment to the host. Our study also unraveled the presence of a CRISPR-Cas system in P. stylochi UST20140214-052 a flatworm-associated bacterium possibly suggesting the role of CRISPR-based adaptive immune system against the invading virus particles. Detection of mobile elements and genomic islands (GIs) in all bacterial members highlighted the role of horizontal gene transfer for the acquisition of novel genetic features, likely enhancing the bacterial ecological fitness. These findings are insightful to understand the role of genome diversity in Pseudovibrio as an evolutionary strategy to increase their colonizing success across a wide range of marine eukaryotic hosts.