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Sample records for ecological co-occurrence interactions

  1. Species co-occurrence networks: Can they reveal trophic and non-trophic interactions in ecological communities?

    Science.gov (United States)

    Freilich, Mara A; Wieters, Evie; Broitman, Bernardo R; Marquet, Pablo A; Navarrete, Sergio A

    2018-03-01

    Co-occurrence methods are increasingly utilized in ecology to infer networks of species interactions where detailed knowledge based on empirical studies is difficult to obtain. Their use is particularly common, but not restricted to, microbial networks constructed from metagenomic analyses. In this study, we test the efficacy of this procedure by comparing an inferred network constructed using spatially intensive co-occurrence data from the rocky intertidal zone in central Chile to a well-resolved, empirically based, species interaction network from the same region. We evaluated the overlap in the information provided by each network and the extent to which there is a bias for co-occurrence data to better detect known trophic or non-trophic, positive or negative interactions. We found a poor correspondence between the co-occurrence network and the known species interactions with overall sensitivity (probability of true link detection) equal to 0.469, and specificity (true non-interaction) equal to 0.527. The ability to detect interactions varied with interaction type. Positive non-trophic interactions such as commensalism and facilitation were detected at the highest rates. These results demonstrate that co-occurrence networks do not represent classical ecological networks in which interactions are defined by direct observations or experimental manipulations. Co-occurrence networks provide information about the joint spatial effects of environmental conditions, recruitment, and, to some extent, biotic interactions, and among the latter, they tend to better detect niche-expanding positive non-trophic interactions. Detection of links (sensitivity or specificity) was not higher for well-known intertidal keystone species than for the rest of consumers in the community. Thus, as observed in previous empirical and theoretical studies, patterns of interactions in co-occurrence networks must be interpreted with caution, especially when extending interaction

  2. Deciphering microbial interactions and detecting keystone species with co-occurrence networks

    Directory of Open Access Journals (Sweden)

    David eBerry

    2014-05-01

    Full Text Available Co-occurrence networks produced from microbial survey sequencing data are frequently used to identify interactions between community members. While this approach has potential to reveal ecological processes, it has been insufficiently validated due to the technical limitations inherent in studying complex microbial ecosystems. Here, we simulate multi-species microbial communities with known interaction patterns using generalized Lotka-Volterra dynamics, construct co-occurrence networks, and evaluate how well networks reveal the underlying interactions, and how experimental and ecological parameters can affect network inference and interpretation. We find that co-occurrence networks can recapitulate interaction networks under certain conditions, but that they lose interpretability when the effects of habitat filtering become significant. We demonstrate that networks suffer from local hot spots of spurious correlation in the neighborhood of hub species that engage in many interactions. We also identify topological features associated with keystone species in co-occurrence networks. This study provides a substantiated framework to guide environmental microbiologists in the construction and interpretation of co-occurrence networks from microbial survey datasets.

  3. Deciphering microbial interactions and detecting keystone species with co-occurrence networks.

    Science.gov (United States)

    Berry, David; Widder, Stefanie

    2014-01-01

    Co-occurrence networks produced from microbial survey sequencing data are frequently used to identify interactions between community members. While this approach has potential to reveal ecological processes, it has been insufficiently validated due to the technical limitations inherent in studying complex microbial ecosystems. Here, we simulate multi-species microbial communities with known interaction patterns using generalized Lotka-Volterra dynamics. We then construct co-occurrence networks and evaluate how well networks reveal the underlying interactions and how experimental and ecological parameters can affect network inference and interpretation. We find that co-occurrence networks can recapitulate interaction networks under certain conditions, but that they lose interpretability when the effects of habitat filtering become significant. We demonstrate that networks suffer from local hot spots of spurious correlation in the neighborhood of hub species that engage in many interactions. We also identify topological features associated with keystone species in co-occurrence networks. This study provides a substantiated framework to guide environmental microbiologists in the construction and interpretation of co-occurrence networks from microbial survey datasets.

  4. Ecological traits influence the phylogenetic structure of bird species co-occurrences worldwide

    NARCIS (Netherlands)

    Barnagaud, J.-Y.; Kissling, W.D.; Sandel, B.; Eiserhardt, W.L.; Şekercioğlu, Ç.H.; Enquist, B.J.; Tsirogiannis, C.; Svenning, J.-C.

    2014-01-01

    The extent to which species’ ecological and phylogenetic relatedness shape their co-occurrence patterns at large spatial scales remains poorly understood. By quantifying phylogenetic assemblage structure within geographic ranges of >8000 bird species, we show that global co-occurrence patterns are

  5. Empirically-based modeling and mapping to consider the co-occurrence of ecological receptors and stressors

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    Part of the ecological risk assessment process involves examining the potential for environmental stressors and ecological receptors to co-occur across a landscape. In this study, we introduce a Bayesian joint modeling framework for use in evaluating and mapping the co-occurrence...

  6. Plant-soil interactions promote co-occurrence of three nonnative woody shrubs.

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    Kuebbing, Sara E; Classen, Aimée T; Call, Jaime J; Henning, Jeremiah A; Simberloff, Daniel

    2015-08-01

    Ecosystems containing multiple nonnative plant species are common, but mechanisms promoting their co-occurrence are understudied. Plant-soil interactions contribute to the dominance of singleton species in nonnative ranges because many nonnatives experience stronger positive feedbacks relative to co-occurring natives. Plant-soil interactions could impede other nonnatives if an individual nonnative benefits from its soil community to a greater extent than its neighboring nonnatives, as is seen with natives. However, plant-soil interactions could promote nonnative co-occurrence if a nonnative accumulates beneficial soil mutualists that also assist other nonnatives. Here, we use greenhouse and field experiments to ask whether plant-soil interactions (1) promote the codominance of two common nonnative shrubs (Ligustrum sinense and Lonicera maackii) and (2) facilitate the invasion of a less-common nonnative shrub (Rhamnus davurica) in deciduous forests of the southeastern United States. In the greenhouse, we found that two of the nonnatives, L. maackii and R. davurica, performed better in soils conditioned by nonnative shrubs compared to uninvaded forest soils, which. suggests that positive feedbacks among co-occurring nonnative shrubs can promote continued invasion of a site. In both greenhouse and field experiments, we found consistent signals that the codominance of the nonnatives L. sinense and L. maackii may be at least partially explained by the increased growth of L. sinense in L. maackii soils. Overall, significant effects of plant-soil interactions on shrub performance indicate that plant-soil interactions can potentially structure the co-occurrence patterns of these nonnatives.

  7. Bayesian Inference of Ecological Interactions from Spatial Data

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    Christopher R. Stephens

    2017-11-01

    Full Text Available The characterization and quantification of ecological interactions and the construction of species’ distributions and their associated ecological niches are of fundamental theoretical and practical importance. In this paper, we discuss a Bayesian inference framework, which, using spatial data, offers a general formalism within which ecological interactions may be characterized and quantified. Interactions are identified through deviations of the spatial distribution of co-occurrences of spatial variables relative to a benchmark for the non-interacting system and based on a statistical ensemble of spatial cells. The formalism allows for the integration of both biotic and abiotic factors of arbitrary resolution. We concentrate on the conceptual and mathematical underpinnings of the formalism, showing how, using the naive Bayes approximation, it can be used to not only compare and contrast the relative contribution from each variable, but also to construct species’ distributions and ecological niches based on an arbitrary variable type. We also show how non-linear interactions between distinct niche variables can be identified and the degree of confounding between variables accounted for.

  8. Factors mediating co-occurrence of an economically valuable introduced fish and its native frog prey.

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    Hartman, Rosemary; Pope, Karen; Lawler, Sharon

    2014-06-01

    Habitat characteristics mediate predator-prey coexistence in many ecological systems but are seldom considered in species introductions. When economically important introduced predators are stocked despite known negative impacts on native species, understanding the role of refuges, landscape configurations, and community interactions can inform habitat management plans. We measured these factors in basins with introduced trout (Salmonidae) and the Cascades frog (Rana cascadae) to determine, which are responsible for observed patterns of co-occurrence of this economically important predator and its native prey. Large, vegetated shallows were strongly correlated to co-occurrence, and R. cascadae larvae occur in shallower water when fish are present, presumably to escape predation. The number of nearby breeding sites of R. cascadae was also correlated to co-occurrence, but only when the western toad (Anaxyrus boreas) was present. Because A. boreas larvae are unpalatable to fish and resemble R. cascadae, they may provide protection from trout via Batesian mimicry. Although rescue-effect dispersal from nearby populations may maintain co-occurrence, within-lake factors proved more important for predicting co-occurrence. Learning which factors allow co-occurrence between economically important introduced species and their native prey enables managers to make better-informed stocking decisions. © 2013 Society for Conservation Biology.

  9. Microbial co-occurrence relationships in the human microbiome.

    Directory of Open Access Journals (Sweden)

    Karoline Faust

    Full Text Available The healthy microbiota show remarkable variability within and among individuals. In addition to external exposures, ecological relationships (both oppositional and symbiotic between microbial inhabitants are important contributors to this variation. It is thus of interest to assess what relationships might exist among microbes and determine their underlying reasons. The initial Human Microbiome Project (HMP cohort, comprising 239 individuals and 18 different microbial habitats, provides an unprecedented resource to detect, catalog, and analyze such relationships. Here, we applied an ensemble method based on multiple similarity measures in combination with generalized boosted linear models (GBLMs to taxonomic marker (16S rRNA gene profiles of this cohort, resulting in a global network of 3,005 significant co-occurrence and co-exclusion relationships between 197 clades occurring throughout the human microbiome. This network revealed strong niche specialization, with most microbial associations occurring within body sites and a number of accompanying inter-body site relationships. Microbial communities within the oropharynx grouped into three distinct habitats, which themselves showed no direct influence on the composition of the gut microbiota. Conversely, niches such as the vagina demonstrated little to no decomposition into region-specific interactions. Diverse mechanisms underlay individual interactions, with some such as the co-exclusion of Porphyromonaceae family members and Streptococcus in the subgingival plaque supported by known biochemical dependencies. These differences varied among broad phylogenetic groups as well, with the Bacilli and Fusobacteria, for example, both enriched for exclusion of taxa from other clades. Comparing phylogenetic versus functional similarities among bacteria, we show that dominant commensal taxa (such as Prevotellaceae and Bacteroides in the gut often compete, while potential pathogens (e.g. Treponema and

  10. Microbial Co-occurrence Relationships in the Human Microbiome

    Science.gov (United States)

    Izard, Jacques; Segata, Nicola; Gevers, Dirk

    2012-01-01

    The healthy microbiota show remarkable variability within and among individuals. In addition to external exposures, ecological relationships (both oppositional and symbiotic) between microbial inhabitants are important contributors to this variation. It is thus of interest to assess what relationships might exist among microbes and determine their underlying reasons. The initial Human Microbiome Project (HMP) cohort, comprising 239 individuals and 18 different microbial habitats, provides an unprecedented resource to detect, catalog, and analyze such relationships. Here, we applied an ensemble method based on multiple similarity measures in combination with generalized boosted linear models (GBLMs) to taxonomic marker (16S rRNA gene) profiles of this cohort, resulting in a global network of 3,005 significant co-occurrence and co-exclusion relationships between 197 clades occurring throughout the human microbiome. This network revealed strong niche specialization, with most microbial associations occurring within body sites and a number of accompanying inter-body site relationships. Microbial communities within the oropharynx grouped into three distinct habitats, which themselves showed no direct influence on the composition of the gut microbiota. Conversely, niches such as the vagina demonstrated little to no decomposition into region-specific interactions. Diverse mechanisms underlay individual interactions, with some such as the co-exclusion of Porphyromonaceae family members and Streptococcus in the subgingival plaque supported by known biochemical dependencies. These differences varied among broad phylogenetic groups as well, with the Bacilli and Fusobacteria, for example, both enriched for exclusion of taxa from other clades. Comparing phylogenetic versus functional similarities among bacteria, we show that dominant commensal taxa (such as Prevotellaceae and Bacteroides in the gut) often compete, while potential pathogens (e.g. Treponema and Prevotella in the

  11. Co-occurrence and hybridization of anther-smut pathogens specialized on Dianthus hosts.

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    Petit, Elsa; Silver, Casey; Cornille, Amandine; Gladieux, Pierre; Rosenthal, Lisa; Bruns, Emily; Yee, Sarah; Antonovics, Janis; Giraud, Tatiana; Hood, Michael E

    2017-04-01

    Host specialization has important consequences for the diversification and ecological interactions of obligate pathogens. The anther-smut disease of natural plant populations, caused by Microbotryum fungi, has been characterized by specialized host-pathogen interactions, which contribute in part to the isolation among these numerous fungal species. This study investigated the molecular variation of Microbotryum pathogens within the geographic and host-specific distributions on wild Dianthus species in southern European Alps. In contrast to prior studies on this pathogen genus, a range of overlapping host specificities was observed for four delineated Microbotryum lineages on Dianthus hosts, and their frequent co-occurrence within single-host populations was quantified at local and regional scales. In addition to potential consequences for direct pathogen competition, the sympatry of Microbotryum lineages led to hybridization between them in many populations, and these admixed genotypes suffered significant meiotic sterility. Therefore, this investigation of the anther-smut fungi reveals how variation in the degrees of host specificity can have major implications for ecological interactions and genetic integrity of differentiated pathogen lineages. © 2017 John Wiley & Sons Ltd.

  12. Plant-pollinator interactions over 120 years: loss of species, co-occurrence, and function.

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    Burkle, Laura A; Marlin, John C; Knight, Tiffany M

    2013-03-29

    Using historic data sets, we quantified the degree to which global change over 120 years disrupted plant-pollinator interactions in a temperate forest understory community in Illinois, USA. We found degradation of interaction network structure and function and extirpation of 50% of bee species. Network changes can be attributed to shifts in forb and bee phenologies resulting in temporal mismatches, nonrandom species extinctions, and loss of spatial co-occurrences between extant species in modified landscapes. Quantity and quality of pollination services have declined through time. The historic network showed flexibility in response to disturbance; however, our data suggest that networks will be less resilient to future changes.

  13. Are there co-occurrence patterns that structure snake communities in Central Brazil?

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    França, F G R; Araújo, A F B

    2007-02-01

    The main factors that structure Neotropical animal communities have been the subject of discussion in ecology communities. We used a set of null models to investigate the existence of structure in snake communities from the Cerrado in Central Brazil in relation to the co-occurrence of species and guilds concerning specific resources. We used fragments (conservation units) inside the Distrito Federal and neighbor municipalities. In spite of recent human colonization in the region from the end of the 1950s, intense habitat modification and fragmentation has taken place. Sixty three snake species are present in the Distrito Federal. Co-occurrence analysis of species and guilds associated to snake diets and habitats suggested a lack of organization. The homogeneity of habitats in Central Brazil and the minor importance of ecological effects can lead to random arrangement.

  14. Fire modifies the phylogenetic structure of soil bacterial co-occurrence networks.

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    Pérez-Valera, Eduardo; Goberna, Marta; Faust, Karoline; Raes, Jeroen; García, Carlos; Verdú, Miguel

    2017-01-01

    Fire alters ecosystems by changing the composition and community structure of soil microbes. The phylogenetic structure of a community provides clues about its main assembling mechanisms. While environmental filtering tends to reduce the community phylogenetic diversity by selecting for functionally (and hence phylogenetically) similar species, processes like competitive exclusion by limiting similarity tend to increase it by preventing the coexistence of functionally (and phylogenetically) similar species. We used co-occurrence networks to detect co-presence (bacteria that co-occur) or exclusion (bacteria that do not co-occur) links indicative of the ecological interactions structuring the community. We propose that inspecting the phylogenetic structure of co-presence or exclusion links allows to detect the main processes simultaneously assembling the community. We monitored a soil bacterial community after an experimental fire and found that fire altered its composition, richness and phylogenetic diversity. Both co-presence and exclusion links were more phylogenetically related than expected by chance. We interpret such a phylogenetic clustering in co-presence links as a result of environmental filtering, while that in exclusion links reflects competitive exclusion by limiting similarity. This suggests that environmental filtering and limiting similarity operate simultaneously to assemble soil bacterial communities, widening the traditional view that only environmental filtering structures bacterial communities. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Predicting what helminth parasites a fish species should have using Parasite Co-occurrence Modeler (PaCo)

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    Strona, Giovanni; Lafferty, Kevin D.

    2013-01-01

    Fish pathologists are often interested in which parasites would likely be present in a particular host. Parasite Co-occurrence Modeler (PaCo) is a tool for identifying a list of parasites known from fish species that are similar ecologically, phylogenetically, and geographically to the host of interest. PaCo uses data from FishBase (maximum length, growth rate, life span, age at maturity, trophic level, phylogeny, and biogeography) to estimate compatibility between a target host and parasite species–genera from the major helminth groups (Acanthocephala, Cestoda, Monogenea, Nematoda, and Trematoda). Users can include any combination of host attributes in a model. These unique features make PaCo an innovative tool for addressing both theoretical and applied questions in parasitology. In addition to predicting the occurrence of parasites, PaCo can be used to investigate how host characteristics shape parasite communities. To test the performance of the PaCo algorithm, we created 12,400 parasite lists by applying any possible combination of model parameters (248) to 50 fish hosts. We then measured the relative importance of each parameter by assessing their frequency in the best models for each host. Host phylogeny and host geography were identified as the most important factors, with both present in 88% of the best models. Habitat (64%) was identified in more than half of the best models. Among ecological parameters, trophic level (41%) was the most relevant while life span (34%), growth rate (32%), maximum length (28%), and age at maturity (20%) were less commonly linked to best models. PaCo is free to use at www.purl.oclc.org/fishpest.

  16. Using species co-occurrence networks to assess the impacts of climate change

    DEFF Research Database (Denmark)

    Bastos Araujo, Miguel; Rozenfeld, Alejandro; Rahbek, Carsten

    2011-01-01

    Viable populations of species occur in a given place if three conditions are met: the environment at the place is suitable; the species is able to colonize it; co-occurrence is possible despite or because of interactions with other species. Studies investigating the effects of climate change...... on species have mainly focused on measuring changes in climate suitability. Complex interactions among species have rarely been explored in such studies. We extend network theory to the analysis of complex patterns of co-occurrence among species. The framework is used to explore the robustness of networks...... under climate change. With our data, we show that networks describing the geographic pattern of co-occurrence among species display properties shared by other complex networks, namely that most species are poorly connected to other species in the network and only a few are highly connected. In our...

  17. Bacterial networks and co-occurrence relationships in the lettuce root microbiota.

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    Cardinale, Massimiliano; Grube, Martin; Erlacher, Armin; Quehenberger, Julian; Berg, Gabriele

    2015-01-01

    Lettuce is one of the most common raw foods worldwide, but occasionally also involved in pathogen outbreaks. To understand the correlative structure of the bacterial community as a network, we studied root microbiota of eight ancient and modern Lactuca sativa cultivars and the wild ancestor Lactuca serriola by pyrosequencing of 16S rRNA gene amplicon libraries. The lettuce microbiota was dominated by Proteobacteria and Bacteriodetes, as well as abundant Chloroflexi and Actinobacteria. Cultivar specificity comprised 12.5% of the species. Diversity indices were not different between lettuce cultivar groups but higher than in L. serriola, suggesting that domestication lead to bacterial diversification in lettuce root system. Spearman correlations between operational taxonomic units (OTUs) showed that co-occurrence prevailed over co-exclusion, and complementary fluorescence in situ hybridization-confocal laser scanning microscopy (FISH-CLSM) analyses revealed that this pattern results from both potential interactions and habitat sharing. Predominant taxa, such as Pseudomonas, Flavobacterium and Sphingomonadaceae rather suggested interactions, even though these are not necessarily part of significant modules in the co-occurrence networks. Without any need for complex interactions, single organisms are able to invade into this microbial network and to colonize lettuce plants, a fact that can influence the susceptibility to pathogens. The approach to combine co-occurrence analysis and FISH-CLSM allows reliably reconstructing and interpreting microbial interaction networks. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Co-occurrence patterns in aquatic bacterial communities across changing permafrost landscapes

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    Comte, J.; Lovejoy, C.; Crevecoeur, S.; Vincent, W. F.

    2016-01-01

    Permafrost thaw ponds and lakes are widespread across the northern landscape and may play a central role in global biogeochemical cycles, yet knowledge about their microbial ecology is limited. We sampled a set of thaw ponds and lakes as well as shallow rock-basin lakes that are located in distinct valleys along a north-south permafrost degradation gradient. We applied high-throughput sequencing of the 16S rRNA gene to determine co-occurrence patterns among bacterial taxa (operational taxonomic units, OTUs), and then analyzed these results relative to environmental variables to identify variables controlling bacterial community structure. Network analysis was applied to identify possible ecological linkages among the bacterial taxa and with abiotic and biotic variables. The results showed an overall high level of shared taxa among bacterial communities within each valley; however, the bacterial co-occurrence patterns were non-random, with evidence of habitat preferences. There were taxonomic differences in bacterial assemblages among the different valleys that were statistically related to dissolved organic carbon concentration, conductivity and phytoplankton biomass. Co-occurrence networks revealed complex interdependencies within the bacterioplankton communities and showed contrasting linkages to environmental conditions among the main bacterial phyla. The thaw pond networks were composed of a limited number of highly connected taxa. This "small world network" property would render the communities more robust to environmental change but vulnerable to the loss of microbial "keystone species". These highly connected nodes (OTUs) in the network were not merely the numerically dominant taxa, and their loss would alter the organization of microbial consortia and ultimately the food web structure and functioning of these aquatic ecosystems.

  19. Positive emotion, appraisal, and the role of appraisal overlap in positive emotion co-occurrence.

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    Tong, Eddie M W; Jia, Lile

    2017-02-01

    Appraisal research has traditionally focused on negative emotions but has not addressed issues concerning the relationships between several positive emotions and appraisals in daily life and the extent to which co-occurrence of positive emotions can be explained by overlap in appraisals. Driven by a priori hypotheses on appraisal-emotion relationships, this study investigated 12 positive emotions and 13 appraisal dimensions using Ecological Momentary Assessment. The results provide strong evidence that positive emotions and appraisals correlate significantly in daily life. Importantly, we found that the positive emotions' overlap on theoretically relevant, as compared to irrelevant, appraisals was stronger and more predictive of their co-occurrence. Furthermore, appraisal overlap on theoretically relevant appraisals predicted the co-occurrence of positive emotions even when the appraisal of pleasantness was excluded, indicating that positive emotions do not co-occur just by virtue of their shared valence. Our findings affirmed and refined the appraisal profiles of positive emotions and underscore the importance of appraisals in accounting for the commonality and differences among positive emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. TelCoVis: Visual Exploration of Co-occurrence in Urban Human Mobility Based on Telco Data.

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    Wu, Wenchao; Xu, Jiayi; Zeng, Haipeng; Zheng, Yixian; Qu, Huamin; Ni, Bing; Yuan, Mingxuan; Ni, Lionel M

    2016-01-01

    Understanding co-occurrence in urban human mobility (i.e. people from two regions visit an urban place during the same time span) is of great value in a variety of applications, such as urban planning, business intelligence, social behavior analysis, as well as containing contagious diseases. In recent years, the widespread use of mobile phones brings an unprecedented opportunity to capture large-scale and fine-grained data to study co-occurrence in human mobility. However, due to the lack of systematic and efficient methods, it is challenging for analysts to carry out in-depth analyses and extract valuable information. In this paper, we present TelCoVis, an interactive visual analytics system, which helps analysts leverage their domain knowledge to gain insight into the co-occurrence in urban human mobility based on telco data. Our system integrates visualization techniques with new designs and combines them in a novel way to enhance analysts' perception for a comprehensive exploration. In addition, we propose to study the correlations in co-occurrence (i.e. people from multiple regions visit different places during the same time span) by means of biclustering techniques that allow analysts to better explore coordinated relationships among different regions and identify interesting patterns. The case studies based on a real-world dataset and interviews with domain experts have demonstrated the effectiveness of our system in gaining insights into co-occurrence and facilitating various analytical tasks.

  1. The Effects of Daily Co-Occurrence of Affect on Older Adults’ Reactivity to Health Stressors

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    Ramsey, Jennifer L.; Neupert, Shevaun D.; Mroczek, Daniel K.; Spiro, Avron

    2015-01-01

    Objectives The present study examined age differences among older adults in the daily co-occurrence of affect and its potential role in buffering the negative effects of health stressors. Design Participants were from the Veterans Affairs Normative Aging Study (NAS) and included 249 young-old adults (age = 60–79 years, M=71.6) and 64 old-old adults (age = 80–89, M = 82.9) who completed questionnaires assessing stressors, physical health symptoms, and positive and negative affect on eight consecutive days. Results An independent samples t-test showed young-old and old-old adults did not significantly differ in their mean levels of daily co-occurrence of affect. The between-person relationships among stressors, health, and daily co-occurrence of affect revealed that neither stressors nor health were significantly related to daily co-occurrence of affect. However, results from a multilevel model revealed a three-way cross-level interaction (Health Stressor X Age Group X Co-Occurrence of Affect) where old-old adults with higher levels of co-occurrence of affect were less emotionally reactive to health stressors than young-old adults. Conclusion These findings provide support for the assertion that co-occurrence of affect functions in an adaptive capacity and highlight the importance of examining domain specific stressors. PMID:26518259

  2. The effects of daily co-occurrence of affect on older adults' reactivity to health stressors.

    Science.gov (United States)

    Ramsey, Jennifer L; Neupert, Shevaun D; Mroczek, Daniel K; Spiro, Avron

    2016-01-01

    The present study examined age differences among older adults in the daily co-occurrence of affect and its potential role in buffering the negative effects of health stressors. Participants were from the Veterans Affairs Normative Aging Study and included 249 young-old adults (age = 60-79 years, M = 71.6) and 64 old-old adults (age = 80-89, M = 82.9) who completed questionnaires assessing stressors, physical health symptoms, and positive and negative affect for eight consecutive days. An independent samples t-test showed young-old and old-old adults did not significantly differ in their mean levels of daily co-occurrence of affect. The between-person relationships among stressors, health and daily co-occurrence of affect revealed that neither stressors nor health were significantly related to daily co-occurrence of affect. However, results from a multilevel model revealed a three-way cross-level interaction (health stressor × age group × co-occurrence of affect) where old-old adults with higher levels of co-occurrence of affect were less emotionally reactive to health stressors than young-old adults. These findings provide support for the assertion that co-occurrence of affect functions in an adaptive capacity and highlight the importance of examining domain-specific stressors.

  3. Phylogenetic relatedness limits co-occurrence at fine spatial scales: evidence from the schoenoid sedges (Cyperaceae: Schoeneae) of the Cape Floristic Region, South Africa.

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    Slingsby, Jasper A; Verboom, G Anthony

    2006-07-01

    Species co-occurrence at fine spatial scales is expected to be nonrandom with respect to phylogeny because of the joint effects of evolutionary (trait convergence and conservatism) and ecological (competitive exclusion and habitat filtering) processes. We use data from 11 existing vegetation surveys to test whether co-occurrence in schoenoid sedge assemblages in the Cape Floristic Region shows significant phylogenetic structuring and to examine whether this changes with the phylogenetic scale of the analysis. We provide evidence for phylogenetic overdispersion in an alliance of closely related species (the reticulate-sheathed Tetraria clade) using both quantile regression analysis and a comparison between the mean observed and expected phylogenetic distances between co-occurring species. Similar patterns are not evident when the analyses are performed at a broader phylogenetic scale. Examination of six functional traits suggests a general pattern of trait conservatism within the reticulate-sheathed Tetraria clade, suggesting a potential role for interspecific competition in structuring co-occurrence within this group. We suggest that phylogenetic overdispersion of communities may be common throughout many of the Cape lineages, since interspecific interactions are likely intensified in lineages with large numbers of species restricted to a small geographic area, and we discuss the potential implications for patterns of diversity in the Cape.

  4. [Co-occurrence of soil fauna communities with changes in altitude on the northern slope of Changbai Mountain].

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    Tong, Fuchun; Jin, Zhedong; Wang, Qingli; Xiao, Yihua

    2003-10-01

    The co-occurrence of soil fauna communities at different altitudes may reflect at some extent the relationships among communities, their coexistence, and the replacement of species along the altitude gradient. The continuous or disjunctive distribution of different species along altitude gradient not only reflected the environment variation at altitude gradient, but also the biological and ecological spatiality as well as the adaptability of species. The northern slope of Changbai Moutain has not only a high diversity in soil fauna types and species, but also a high variation of diversity pattern along the altitude gradient, which is a perfect transect for the research of biodiversity and gradient patterns. From 550 m to 2,560 m on the northern slope of Changbai Mountain, twenty-two plots were investigated with an interval of 100 m in altitude. By using Jaccard index, the co-occurrence of soil fauna communities at different altitudes was analyzed. For the species of different life forms or for all the species as a whole, the co-occurrence of soil faunae between neighboring communities was the highest, except for that between different soil fauna types. The peak and valley values of the co-occurrence of soil fauna communities along altitude gradient were matched with their gradient patterns, and the co-occurrence of soil faunae at different layers or all of the soil fauna communities were decreased with increasing altitude difference.

  5. Codon based co-occurrence network motifs in human mitochondria

    Directory of Open Access Journals (Sweden)

    Pramod Shinde

    2017-10-01

    Full Text Available The nucleotide polymorphism in human mitochondrial genome (mtDNA tolled by codon position bias plays an indispensable role in human population dispersion and expansion. Herein, we constructed genome-wide nucleotide co-occurrence networks using a massive data consisting of five different geographical regions and around 3000 samples for each region. We developed a powerful network model to describe complex mitochondrial evolutionary patterns between codon and non-codon positions. It was interesting to report a different evolution of Asian genomes than those of the rest which is divulged by network motifs. We found evidence that mtDNA undergoes substantial amounts of adaptive evolution, a finding which was supported by a number of previous studies. The dominance of higher order motifs indicated the importance of long-range nucleotide co-occurrence in genomic diversity. Most notably, codon motifs apparently underpinned the preferences among codon positions for co-evolution which is probably highly biased during the origin of the genetic code. Our analyses manifested that codon position co-evolution is very well conserved across human sub-populations and independently maintained within human sub-populations implying the selective role of evolutionary processes on codon position co-evolution. Ergo, this study provided a framework to investigate cooperative genomic interactions which are critical in underlying complex mitochondrial evolution.

  6. Differential sharing and distinct co-occurrence networks among spatially close bacterial microbiota of bark, mosses and lichens‬‬.

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    Aschenbrenner, Ines Aline; Cernava, Tomislav; Erlacher, Armin; Berg, Gabriele; Grube, Martin

    2017-05-01

    Knowledge of bacterial community host-specificity has increased greatly in recent years. However, the intermicrobiome relationships of unrelated but spatially close organisms remain little understood. Trunks of trees covered by epiphytes represent complex habitats with a mosaic of ecological niches. In this context, we investigated the structure, diversity and interactions of microbiota associated with lichens, mosses and the bare tree bark. Comparative analysis revealed significant differences in the habitat-associated community structures. Corresponding co-occurrence analysis indicated that the lichen microbial network is less complex and less densely interconnected than the moss- and bark-associated networks. Several potential generalists and specialists were identified for the selected habitats. Generalists belonged mainly to Proteobacteria, with Sphingomonas as the most abundant genus. The generalists comprise microorganisms with generally beneficial features, such as nitrogen fixation or other supporting functions, according to a metagenomic analysis. We argue that beneficial strains shared among hosts contribute to ecological stability of the host biocoenoses. © 2017 John Wiley & Sons Ltd.

  7. Antimicrobial discovery inspired by ecological interactions.

    Science.gov (United States)

    Molloy, Evelyn M; Hertweck, Christian

    2017-10-01

    Bacteria represent an unparalleled source of antibiotics used to treat infectious diseases. Yet, genome analyses have revealed that their full biosynthetic potential is much larger than expected. Valuable strategies to unearth hidden antibiotics are genome mining, pathway engineering and triggering, as well as co-cultivation approaches. Nevertheless, there is growing understanding that it is often essential to consider the ecological context and that there is a great potential for antimicrobial discovery from bacteria engaged in well-defined interactions with other organisms. Various ecological scenarios involving antimicrobial agents are outlined in this review: predator-prey and pathogenic interactions, the protection of insect assets such as offspring and cultivars, as well as host protection in symbiotic relationships with plants, invertebrates and animals/humans. The illustrative examples given reinforce the idea that examination of interactions between organisms can yield new antimicrobial compounds, and ultimately further our understanding of the function of these molecules in the environment. Copyright © 2017. Published by Elsevier Ltd.

  8. Effort-reward imbalance at work and the co-occurrence of lifestyle risk factors: cross-sectional survey in a sample of 36,127 public sector employees.

    Science.gov (United States)

    Kouvonen, Anne; Kivimäki, Mika; Virtanen, Marianna; Heponiemi, Tarja; Elovainio, Marko; Pentti, Jaana; Linna, Anne; Vahtera, Jussi

    2006-02-07

    In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI) model--effort, rewards and ERI--are associated with the co-occurrence of lifestyle risk factors. Based on data from the Finnish Public Sector Study, cross-sectional analyses were performed for 28,894 women and 7233 men. ERI was conceptualized as a ratio of effort and rewards. To control for individual differences in response styles, such as a personal disposition to answer negatively to questionnaires, occupational and organizational-level ecological ERI scores were constructed in addition to individual-level ERI scores. Risk factors included current smoking, heavy drinking, body mass index > or =25 kg/m2, and physical inactivity. Multinomial logistic regression models were used to estimate the likelihood of having one risk factor, two risk factors, and three or four risk factors. The associations between ERI and single risk factors were explored using binary logistic regression models. After adjustment for age, socioeconomic position, marital status, and type of job contract, women and men with high ecological ERI were 40% more likely to have simultaneously > or =3 lifestyle risk factors (vs. 0 risk factors) compared with their counterparts with low ERI. When examined separately, both low ecological effort and low ecological rewards were also associated with an elevated prevalence of risk factor co-occurrence. The results obtained with the individual-level scores were in the same direction. The associations of ecological ERI with single risk factors were generally less marked than the associations with the co-occurrence of risk factors. This study suggests that a high ratio of occupational efforts relative to rewards may be

  9. Interactions between Climate, Land Use and Vegetation Fire Occurrences in El Salvador

    Directory of Open Access Journals (Sweden)

    Dolors Armenteras

    2016-02-01

    Full Text Available Vegetation burning is a global environmental threat that results in local ecological, economic and social impacts but also has large-scale implications for global change. The burning is usually a result of interacting factors such as climate, land use and vegetation type. Despite its importance as a factor shaping ecological, economic and social processes, countries highly vulnerable to climate change in Central America, such as El Salvador, lack an assessment of this complex relationship. In this study we rely on remotely sensed measures of the Normalized Vegetation Difference Index (NDVI and thermal anomaly detections by the Moderate Resolution Imaging Spectroradiometer (MODIS sensor to identify vegetation cover changes and fire occurrences. We also use land use data and rainfall observations derived from the Tropical Rainfall Measuring Mission (TRMM data to determine the spatial and temporal variability and interactions of these factors. Our results indicate a highly marked seasonality of fire occurrence linked to the climatic variability with a peak of fire occurrences in 2004 and 2013. Low vegetation indices occurred in March–April, around two months after the driest period of the year (December–February, corresponding to months with high detection of fires. Spatially, 65.6% of the fires were recurrent and clustered in agriculture/cropland areas and within 1 km of roads (70% and only a 4.7% of fires detected were associated with forests. Remaining forests in El Salvador deserve more attention due to underestimated consequences of forest fires. The identification of these clear patterns can be used as a baseline to better shape management of fire regimes and support decision making in this country. Recommendations resulting from this work include focusing on fire risk models and agriculture fires and long-term ecological and economic consequences of those. Furthermore, El Salvador will need to include agricultural fires in the

  10. Non-random co-occurrence of native and exotic plant species in Mediterranean grasslands

    Science.gov (United States)

    de Miguel, José M.; Martín-Forés, Irene; Acosta-Gallo, Belén; del Pozo, Alejandro; Ovalle, Carlos; Sánchez-Jardón, Laura; Castro, Isabel; Casado, Miguel A.

    2016-11-01

    Invasion by exotic species in Mediterranean grasslands has determined assembly patterns of native and introduced species, knowledge of which provides information on the ecological processes underlying these novel communities. We considered grasslands from Spain and Chile. For each country we considered the whole grassland community and we split species into two subsets: in Chile, species were classified as natives or colonizers (i.e. exotics); in Spain, species were classified as exclusives (present in Spain but not in Chile) or colonizers (Spanish natives and exotics into Chile). We used null models and co-occurrence indices calculated in each country for each one of 15 sites distributed along a precipitation gradient and subjected to similar silvopastoral exploitation. We compared values of species co-occurrence between countries and between species subsets (natives/colonizers in Chile; exclusives/colonizers in Spain) within each country and we characterised them according to climatic variables. We hypothesized that: a) the different coexistence time of the species in both regions should give rise to communities presenting a spatial pattern further from random in Spain than in Chile, b) the co-occurrence patterns in the grasslands are affected by mesoclimatic factors in both regions. The patterns of co-occurrence are similar in Spain and Chile, mostly showing a spatial pattern more segregated than expected by random. The colonizer species are more segregated in Spain than in Chile, possibly determined by the longer residence time of the species in the source area than in the invaded one. The segregation of species in Chile is related to water availability, being species less segregated in habitat with greater water deficit; in Spain no relationship with climatic variables was found. After an invasion process, our results suggest that the possible process of alteration of the original Chilean communities has not prevented the assembly between the native and

  11. Trypanosoma cruzi reservoir—triatomine vector co-occurrence networks reveal meta-community effects by synanthropic mammals on geographic dispersal

    Directory of Open Access Journals (Sweden)

    Carlos N. Ibarra-Cerdeña

    2017-04-01

    Full Text Available Contemporary patterns of land use and global climate change are modifying regional pools of parasite host species. The impact of host community changes on human disease risk, however, is difficult to assess due to a lack of information about zoonotic parasite host assemblages. We have used a recently developed method to infer parasite-host interactions for Chagas Disease (CD from vector-host co-occurrence networks. Vector-host networks were constructed to analyze topological characteristics of the network and ecological traits of species’ nodes, which could provide information regarding parasite regional dispersal in Mexico. Twenty-eight triatomine species (vectors and 396 mammal species (potential hosts were included using a data-mining approach to develop models to infer most-likely interactions. The final network contained 1,576 links which were analyzed to calculate centrality, connectivity, and modularity. The model predicted links of independently registered Trypanosoma cruzi hosts, which correlated with the degree of parasite-vector co-occurrence. Wiring patterns differed according to node location, while edge density was greater in Neotropical as compared to Nearctic regions. Vectors with greatest public health importance (i.e., Triatoma dimidiata, T. barberi, T. pallidipennis, T. longipennis, etc, did not have stronger links with particular host species, although they had a greater frequency of significant links. In contrast, hosts classified as important based on network properties were synanthropic mammals. The latter were the most common parasite hosts and are likely bridge species between these communities, thereby integrating meta-community scenarios beneficial for long-range parasite dispersal. This was particularly true for rodents, >50% of species are synanthropic and more than 20% have been identified as T. cruzi hosts. In addition to predicting potential host species using the co-occurrence networks, they reveal regions with

  12. Effort-reward imbalance at work and the co-occurrence of lifestyle risk factors: cross-sectional survey in a sample of 36,127 public sector employees

    Science.gov (United States)

    Kouvonen, Anne; Kivimäki, Mika; Virtanen, Marianna; Heponiemi, Tarja; Elovainio, Marko; Pentti, Jaana; Linna, Anne; Vahtera, Jussi

    2006-01-01

    Background In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI) model – effort, rewards and ERI – are associated with the co-occurrence of lifestyle risk factors. Methods Based on data from the Finnish Public Sector Study, cross-sectional analyses were performed for 28,894 women and 7233 men. ERI was conceptualized as a ratio of effort and rewards. To control for individual differences in response styles, such as a personal disposition to answer negatively to questionnaires, occupational and organizational -level ecological ERI scores were constructed in addition to individual-level ERI scores. Risk factors included current smoking, heavy drinking, body mass index ≥25 kg/m2, and physical inactivity. Multinomial logistic regression models were used to estimate the likelihood of having one risk factor, two risk factors, and three or four risk factors. The associations between ERI and single risk factors were explored using binary logistic regression models. Results After adjustment for age, socioeconomic position, marital status, and type of job contract, women and men with high ecological ERI were 40% more likely to have simultaneously ≥3 lifestyle risk factors (vs. 0 risk factors) compared with their counterparts with low ERI. When examined separately, both low ecological effort and low ecological rewards were also associated with an elevated prevalence of risk factor co-occurrence. The results obtained with the individual-level scores were in the same direction. The associations of ecological ERI with single risk factors were generally less marked than the associations with the co-occurrence of risk factors. Conclusion This study suggests that a high ratio of occupational

  13. Effort-reward imbalance at work and the co-occurrence of lifestyle risk factors: cross-sectional survey in a sample of 36,127 public sector employees

    Directory of Open Access Journals (Sweden)

    Elovainio Marko

    2006-02-01

    Full Text Available Abstract Background In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI model – effort, rewards and ERI – are associated with the co-occurrence of lifestyle risk factors. Methods Based on data from the Finnish Public Sector Study, cross-sectional analyses were performed for 28,894 women and 7233 men. ERI was conceptualized as a ratio of effort and rewards. To control for individual differences in response styles, such as a personal disposition to answer negatively to questionnaires, occupational and organizational -level ecological ERI scores were constructed in addition to individual-level ERI scores. Risk factors included current smoking, heavy drinking, body mass index ≥25 kg/m2, and physical inactivity. Multinomial logistic regression models were used to estimate the likelihood of having one risk factor, two risk factors, and three or four risk factors. The associations between ERI and single risk factors were explored using binary logistic regression models. Results After adjustment for age, socioeconomic position, marital status, and type of job contract, women and men with high ecological ERI were 40% more likely to have simultaneously ≥3 lifestyle risk factors (vs. 0 risk factors compared with their counterparts with low ERI. When examined separately, both low ecological effort and low ecological rewards were also associated with an elevated prevalence of risk factor co-occurrence. The results obtained with the individual-level scores were in the same direction. The associations of ecological ERI with single risk factors were generally less marked than the associations with the co-occurrence of risk factors. Conclusion This study suggests that a high

  14. CO-OCCURRENCE OF DIABETES AND HYPERTENSION ...

    African Journals Online (AJOL)

    cardiovascular disease (CVD), and when they co-exist ... and hypertension among patients with co-occurrence ... are any clinical and metabolic differences between those ... The last 3 readings of their fasting blood .... as insulin resistance, aging, obesity, use of thiazide ... therapy as risk factors for type 2 diabetes mellitus.

  15. A Mutual Hostility Explanation for the Co-Occurrence of Delinquency and Depressive Mood in Adolescence.

    Science.gov (United States)

    Martínez-Ferrer, Belén; Stattin, Håkan

    2017-10-01

    Different interpersonal experiences are related to delinquency and depressive mood. In many studies, delinquency has been associated with exposing others to hostility, while depressive mood has been associated with being a victim of others' hostility. In this study, we proposed that adolescents with a co-occurrence of high delinquency and depressive mood may be both perpetrators and victims in their relations with parents at home, peers and teachers at school, and other people encountered in leisure time. We studied a normative sample of 1452 mid-adolescents (50.61% boys and 49.38% girls). Cluster analyses found a group with a co-occurrence of high delinquency and high depressive mood. Adolescents in this cluster group were highest on being exposed to hostility, exposing others to hostility, and being involved in mutually hostile interactions with others in different everyday contexts. The findings were especially strong when we examined being a victim and a perpetrator across contexts. The results were similar for boys and girls. We conclude that the co-occurrence of high delinquency and depressive mood among some adolescents is intimately linked to the mutually hostile interactions that these adolescents experience in their everyday interpersonal contexts.

  16. Utilization and control of ecological interactions in polymicrobial infections and community-based microbial cell factories

    DEFF Research Database (Denmark)

    Wigneswaran, Vinoth; Amador Hierro, Cristina Isabel; Jelsbak, Lotte

    2016-01-01

    Microbial activities are most often shaped by interactions between co-existing microbes within mixed-species communities. Dissection of the molecular mechanisms of species interactions within communities is a central issue in microbial ecology, and our ability to engineer and control microbial co...

  17. Non-additive costs and interactions alter the competitive dynamics of co-occurring ecologically distinct plasmids.

    Science.gov (United States)

    Morton, Elise R; Platt, Thomas G; Fuqua, Clay; Bever, James D

    2014-03-22

    Plasmids play an important role in shaping bacterial evolution and adaptation to heterogeneous environments. As modular genetic elements that are often conjugative, the selective pressures that act on plasmid-borne genes are distinct from those that act on the chromosome. Many bacteria are co-infected by multiple plasmids that impart niche-specific phenotypes. Thus, in addition to host-plasmid dynamics, interactions between co-infecting plasmids are likely to be important drivers of plasmid population dynamics, evolution and ecology. Agrobacterium tumefaciens is a facultative plant pathogen that commonly harbours two distinct megaplasmids. Virulence depends on the presence of the tumour-inducing (Ti) plasmid, with benefits that are primarily restricted to the disease environment. Here, we demonstrate that a second megaplasmid, the At plasmid, confers a competitive advantage in the rhizosphere. To assess the individual and interactive costs of these plasmids, we generated four isogenic derivatives: plasmidless, pAt only, pTi only and pAtpTi, and performed pairwise competitions under carbon-limiting conditions. These studies reveal a low cost to the virulence plasmid when outside of the disease environment, and a strikingly high cost to the At plasmid. In addition, the costs of pAt and pTi in the same host were significantly lower than predicted based on single plasmid costs, signifying the first demonstration of non-additivity between naturally occurring co-resident plasmids. Based on these empirically demonstrated costs and benefits, we developed a resource-consumer model to generate predictions about the frequencies of these genotypes in relevant environments, showing that non-additivity between co-residing plasmids allows for their stable coexistence across environments.

  18. The effect of evaluation on co-occurrence memory judgement.

    Science.gov (United States)

    Bar-Anan, Yoav; Amzaleg-David, Efrat

    2014-01-01

    Three experiments tested the effect of an attitude towards an object on the memory judgement of whether this object co-occurred with positive versus negative stimuli. We induced positive or negative attitudes towards novel male stimuli, and paired each man with an equal number of positive and negative animals. In a memory test, participants reported more co-occurrences of same-valence man/animal pairs than opposite-valence pairs. This valence-compatibility effect occurred even when attitudes were induced after the pairing (Experiment 1), when participants knew that each man occurred with an equal number of positive and negative animals (Experiment 2), and in reports of clear memory of pairs that did not co-occur (Experiment 3). The present findings suggest that evaluation causes illusory correlation even when the co-occurring stimuli are not traits or behaviours attributed to the attitude object. The results question the validity of co-occurrence memory judgements as measures of co-occurrence awareness in evaluative conditioning (EC) research.

  19. Chasing Ecological Interactions.

    Science.gov (United States)

    Jordano, Pedro

    2016-09-01

    Basic research on biodiversity has concentrated on individual species-naming new species, studying distribution patterns, and analyzing their evolutionary relationships. Yet biodiversity is more than a collection of individual species; it is the combination of biological entities and processes that support life on Earth. To understand biodiversity we must catalog it, but we must also assess the ways species interact with other species to provide functional support for the Tree of Life. Ecological interactions may be lost well before the species involved in those interactions go extinct; their ecological functions disappear even though they remain. Here, I address the challenges in studying the functional aspects of species interactions and how basic research is helping us address the fast-paced extinction of species due to human activities.

  20. Species co-occurrence affects the trophic interactions of two juvenile reef shark species in tropical lagoon nurseries in Moorea (French Polynesia).

    Science.gov (United States)

    Matich, Philip; Kiszka, Jeremy J; Mourier, Johann; Planes, Serge; Heithaus, Michael R

    2017-06-01

    Food web structure is shaped by interactions within and across trophic levels. As such, understanding how the presence and absence of predators, prey, and competitors affect species foraging patterns is important for predicting the consequences of changes in species abundances, distributions, and behaviors. Here, we used plasma δ 13 C and δ 15 N values from juvenile blacktip reef sharks (Carcharhinus melanopterus) and juvenile sicklefin lemon sharks (Negaprion acutidens) to investigate how species co-occurrence affects their trophic interactions in littoral waters of Moorea, French Polynesia. Co-occurrence led to isotopic niche partitioning among sharks within nurseries, with significant increases in δ 15 N values among sicklefin lemon sharks, and significant decreases in δ 15 N among blacktip reef sharks. Niche segregation likely promotes coexistence of these two predators during early years of growth and development, but data do not suggest coexistence affects life history traits, such as body size, body condition, and ontogenetic niche shifts. Plasticity in trophic niches among juvenile blacktip reef sharks and sicklefin lemon sharks also suggests these predators are able to account for changes in community structure, resource availability, and intra-guild competition, and may fill similar functional roles in the absence of the other species, which is important as environmental change and human impacts persist in coral reef ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Detection of stable community structures within gut microbiota co-occurrence networks from different human populations.

    Science.gov (United States)

    Jackson, Matthew A; Bonder, Marc Jan; Kuncheva, Zhana; Zierer, Jonas; Fu, Jingyuan; Kurilshikov, Alexander; Wijmenga, Cisca; Zhernakova, Alexandra; Bell, Jordana T; Spector, Tim D; Steves, Claire J

    2018-01-01

    Microbes in the gut microbiome form sub-communities based on shared niche specialisations and specific interactions between individual taxa. The inter-microbial relationships that define these communities can be inferred from the co-occurrence of taxa across multiple samples. Here, we present an approach to identify comparable communities within different gut microbiota co-occurrence networks, and demonstrate its use by comparing the gut microbiota community structures of three geographically diverse populations. We combine gut microbiota profiles from 2,764 British, 1,023 Dutch, and 639 Israeli individuals, derive co-occurrence networks between their operational taxonomic units, and detect comparable communities within them. Comparing populations we find that community structure is significantly more similar between datasets than expected by chance. Mapping communities across the datasets, we also show that communities can have similar associations to host phenotypes in different populations. This study shows that the community structure within the gut microbiota is stable across populations, and describes a novel approach that facilitates comparative community-centric microbiome analyses.

  2. Species composition, co-occurrence, association and affinity indices of mosquito larvae (Diptera: Culicidae) in Mazandaran Province, northern Iran.

    Science.gov (United States)

    Nikookar, Seyed Hassan; Azari-Hamidian, Shahyad; Fazeli-Dinan, Mahmoud; Nasab, Seyed Nouraddin Mousavi; Aarabi, Mohsen; Ziapour, Seyyed Payman; Enayati, Ahmadali

    2016-05-01

    Although considerable progress has been made in the past years in management of mosquito borne diseases such as malaria, dengue, yellow fever and West Nile fever through research in biology and ecology of the vectors, these diseases are still major threats to human health. Therefore, more research is required for better management of the diseases. This investigation provides information on the composition, co-occurrence, association and affinity indices of mosquito larvae in Mazandaran Province, northern Iran. In a large scale field study, mosquito larvae were collected from 120 sentinel sites in 16 counties in Mazandaran Province, using standard 350 ml dipper. Sampling took place monthly from May to December 2014. Collected larvae were mounted on glass slides using de Faure's medium and were diagnosed using morphological characters. Totally, 19,840 larvae were collected including three genera and 16 species from 120 larval habitats, as follows: Anopheles claviger, Anopheles hyrcanus, Anopheles maculipennis s.l., Anopheles marteri, Anopheles plumbeus, Anopheles pseudopictus, Culex pipiens, Culex tritaeniorhynchus, Culex torrentium, Culex perexiguus, Culex territans, Culex mimeticus, Culex hortensis, Culiseta annulata, Culiseta longiareolata, and Culiseta morsitans. Predominant species were Cx. pipiens and An. maculipennis s.l. which show the highest co-occurrence. The pair of species An. hyrcanus/An. pseudopictus showed significant affinity and association. High co-occurrence of the predominant species Cx. pipiens and An. maculipennis s.l. in the study area is of considerable importance in terms of vector ecology. It was also revealed that An. pseudopictus/An. hyrcanus often occur sympatrically indicating their common habitat requirements. The information may be equally important when vector control measures are considered. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Niche filtering, not interspecific resource competition, explains the co-occurrence of butterfly species across the Japanese archipelago

    OpenAIRE

    Iwasaki, Takaya; Sato, Yasuhiro; Nakadai, Ryosuke; Hashimoto, Koya

    2017-01-01

    The relevance of interspecific resource competition in the context of community assembly by herbivorous insects is a well-known topic in ecology. Most previous studies focused on local species assemblies, that shared host plants. Few studies evaluated species pairs within a single taxon when investigating the effects of host plant sharing at the regional scale. Herein, we explore the effect of plant sharing on the geographical co-occurrence patterns of 229 butterflies distributed across the J...

  4. Analysis of co-occurrence toponyms in web pages based on complex networks

    Science.gov (United States)

    Zhong, Xiang; Liu, Jiajun; Gao, Yong; Wu, Lun

    2017-01-01

    A large number of geographical toponyms exist in web pages and other documents, providing abundant geographical resources for GIS. It is very common for toponyms to co-occur in the same documents. To investigate these relations associated with geographic entities, a novel complex network model for co-occurrence toponyms is proposed. Then, 12 toponym co-occurrence networks are constructed from the toponym sets extracted from the People's Daily Paper documents of 2010. It is found that two toponyms have a high co-occurrence probability if they are at the same administrative level or if they possess a part-whole relationship. By applying complex network analysis methods to toponym co-occurrence networks, we find the following characteristics. (1) The navigation vertices of the co-occurrence networks can be found by degree centrality analysis. (2) The networks express strong cluster characteristics, and it takes only several steps to reach one vertex from another one, implying that the networks are small-world graphs. (3) The degree distribution satisfies the power law with an exponent of 1.7, so the networks are free-scale. (4) The networks are disassortative and have similar assortative modes, with assortative exponents of approximately 0.18 and assortative indexes less than 0. (5) The frequency of toponym co-occurrence is weakly negatively correlated with geographic distance, but more strongly negatively correlated with administrative hierarchical distance. Considering the toponym frequencies and co-occurrence relationships, a novel method based on link analysis is presented to extract the core toponyms from web pages. This method is suitable and effective for geographical information retrieval.

  5. Evolutionary relatedness does not predict competition and co-occurrence in natural or experimental communities of green algae

    Science.gov (United States)

    Alexandrou, Markos A.; Cardinale, Bradley J.; Hall, John D.; Delwiche, Charles F.; Fritschie, Keith; Narwani, Anita; Venail, Patrick A.; Bentlage, Bastian; Pankey, M. Sabrina; Oakley, Todd H.

    2015-01-01

    The competition-relatedness hypothesis (CRH) predicts that the strength of competition is the strongest among closely related species and decreases as species become less related. This hypothesis is based on the assumption that common ancestry causes close relatives to share biological traits that lead to greater ecological similarity. Although intuitively appealing, the extent to which phylogeny can predict competition and co-occurrence among species has only recently been rigorously tested, with mixed results. When studies have failed to support the CRH, critics have pointed out at least three limitations: (i) the use of data poor phylogenies that provide inaccurate estimates of species relatedness, (ii) the use of inappropriate statistical models that fail to detect relationships between relatedness and species interactions amidst nonlinearities and heteroskedastic variances, and (iii) overly simplified laboratory conditions that fail to allow eco-evolutionary relationships to emerge. Here, we address these limitations and find they do not explain why evolutionary relatedness fails to predict the strength of species interactions or probabilities of coexistence among freshwater green algae. First, we construct a new data-rich, transcriptome-based phylogeny of common freshwater green algae that are commonly cultured and used for laboratory experiments. Using this new phylogeny, we re-analyse ecological data from three previously published laboratory experiments. After accounting for the possibility of nonlinearities and heterogeneity of variances across levels of relatedness, we find no relationship between phylogenetic distance and ecological traits. In addition, we show that communities of North American green algae are randomly composed with respect to their evolutionary relationships in 99% of 1077 lakes spanning the continental United States. Together, these analyses result in one of the most comprehensive case studies of how evolutionary history influences

  6. Forbidden versus permitted interactions: Disentangling processes from patterns in ecological network analysis.

    Science.gov (United States)

    Strona, Giovanni; Veech, Joseph A

    2017-07-01

    Several studies have identified the tendency for species to share interacting partners as a key property to the functioning and stability of ecological networks. However, assessing this pattern has proved challenging in several regards, such as finding proper metrics to assess node overlap (sharing), and using robust null modeling to disentangle significance from randomness. Here, we bring attention to an additional, largely neglected challenge in assessing species' tendency to share interacting partners. In particular, we discuss and illustrate with two different case studies how identifying the set of "permitted" interactions for a given species (i.e. interactions that are not impeded, e.g. by lack of functional trait compatibility) is paramount to understand the ecological and co-evolutionary processes at the basis of node overlap and segregation patterns.

  7. Revising ecological assumptions about Human papillomavirus interactions and type replacement.

    Science.gov (United States)

    Murall, Carmen Lía; McCann, Kevin S; Bauch, Chris T

    2014-06-07

    The controversy over whether vaccine-targeted HPV types will be replaced by other oncogenic, non-vaccine-targeted types remains unresolved. This is in part because little is known about the ecology of HPV types. Patient data has been interpreted to suggest independence or facilitative interactions between types and therefore replacement is believed to be unlikely. With a novel mathematical model, we investigated which HPV type interactions and their immune responses gave qualitatively similar patterns frequently observed in patients. To assess the possibility of type replacement, vaccination was added to see if non-vaccine-targeted types increased their 'niche'. Our model predicts that independence and facilitation are not necessary for the coexistence of types inside hosts, especially given the patchy nature of HPV infection. In fact, independence and facilitation inadequately represented co-infected patients. We found that some form of competition is likely in natural co-infections. Hence, non-vaccine-targeted types that are not cross-reactive with the vaccine could spread to more patches and can increase their viral load in vaccinated hosts. The degree to which this happens will depend on replication and patch colonization rates. Our results suggest that independence between types could be a fallacy, and so without conclusively untangling HPV within-host ecology, type replacement remains theoretically viable. More ecological thinking is needed in future studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Occurrence of dichloroacetamide herbicide safeners and co-applied herbicides in midwestern U.S. streams

    Science.gov (United States)

    Woodward, Emily; Hladik, Michelle; Kolpin, Dana W.

    2018-01-01

    Dichloroacetamide safeners (e.g., AD-67, benoxacor, dichlormid, and furilazole) are co-applied with chloroacetanilide herbicides to protect crops from herbicide toxicity. While such safeners have been used since the early 1970s, there are minimal data about safener usage, occurrence in streams, or potential ecological effects. This study focused on one of these research gaps, occurrence in streams. Seven Midwestern U.S. streams (five in Iowa and two in Illinois), with extensive row-crop agriculture, were sampled at varying frequencies from spring 2016 through summer 2017. All four safeners were detected at least once; furilazole was the most frequently detected (31%), followed by benoxacor (29%), dichlormid (15%), and AD-67 (2%). The maximum concentrations ranged from 42 to 190 ng/L. Stream detections and concentrations of safeners appear to be driven by a combination of timing of application (spring following herbicide application) and precipitation events. Detected concentrations were below known toxicity levels for aquatic organisms.

  9. Long-term oil contamination alters the molecular ecological networks of soil microbial functional genes

    Directory of Open Access Journals (Sweden)

    Yuting eLiang

    2016-02-01

    Full Text Available With knowledge on microbial composition and diversity, investigation of within-community interactions is a further step to elucidate microbial ecological functions, such as the biodegradation of hazardous contaminants. In this work, microbial functional molecular ecological networks were studied in both contaminated and uncontaminated soils to determine the possible influences of oil contamination on microbial interactions and potential functions. Soil samples were obtained from an oil-exploring site located in South China, and the microbial functional genes were analyzed with GeoChip, a high-throughput functional microarray. By building random networks based on null model, we demonstrated that overall network structures and properties were significantly different between contaminated and uncontaminated soils (P < 0.001. Network connectivity, module numbers, and modularity were all reduced with contamination. Moreover, the topological roles of the genes (module hub and connectors were altered with oil contamination. Subnetworks of genes involved in alkane and polycyclic aromatic hydrocarbon degradation were also constructed. Negative co-occurrence patterns prevailed among functional genes, thereby indicating probable competition relationships. The potential keystone genes, defined as either hubs or genes with highest connectivities in the network, were further identified. The network constructed in this study predicted the potential effects of anthropogenic contamination on microbial community co-occurrence interactions.

  10. Co-occurrence of chancroid and gonorrhea.

    Science.gov (United States)

    Nawaf, Al-Mutairi; Joshi, Arun; Tayeh, Mohammad

    2006-01-01

    Gonorrhea and chancroid are common sexually transmitted infections in many parts of the world. Still, co-occurrence of these two conditions is uncommonly reported. We present here a patient who presented with painful genital ulcers and urethral discharge simultaneously acquired from a single exposure, which turned out to be chancroid and gonorrhea, respectively. Both conditions responded well to a single intramuscular dose of ceftriaxone 250 mg. This report describes the uncommon occurrence of gonorrhea and chancroid in a patient. Clinical features, relevant investigations, treatment options of these two sexually transmitted infections, and possible implications in view of the human immunodeficiency virus (HIV) pandemic are briefly discussed.

  11. Evolution in a Community Context: On Integrating Ecological Interactions and Macroevolution.

    Science.gov (United States)

    Weber, Marjorie G; Wagner, Catherine E; Best, Rebecca J; Harmon, Luke J; Matthews, Blake

    2017-04-01

    Despite a conceptual understanding that evolution and species interactions are inextricably linked, it remains challenging to study ecological and evolutionary dynamics together over long temporal scales. In this review, we argue that, despite inherent challenges associated with reconstructing historical processes, the interplay of ecology and evolution is central to our understanding of macroevolution and community coexistence, and cannot be safely ignored in community and comparative phylogenetic studies. We highlight new research avenues that foster greater consideration of both ecological and evolutionary dynamics as processes that occur along branches of phylogenetic trees. By promoting new ways forward using this perspective, we hope to inspire further integration that creatively co-utilizes phylogenies and ecological data to study eco-evolutionary dynamics over time and space. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Occupancy of yellow-billed and Pacific loons: evidence for interspecific competition and habitat mediated co-occurrence

    Science.gov (United States)

    Haynes, Trevor B.; Schmutz, Joel A.; Lindberg, Mark S.; Wright, Kenneth G.; Uher-Koch, Brian D.; Rosenberger, Amanda E.

    2014-01-01

    Interspecific competition is an important process structuring ecological communities, however, it is difficult to observe in nature. We used an occupancy modelling approach to evaluate evidence of competition between yellow-billed (Gavia adamsii) and Pacific (G. pacifica) loons for nesting lakes on the Arctic Coastal Plain of Alaska. With multiple years of data and survey platforms, we estimated dynamic occupancy states (e.g. rates of colonization or extinction from individual lakes) and controlled for detection differences among aircraft platforms and ground survey crews. Results indicated that yellow-billed loons were strong competitors and negatively influenced the occupancy of Pacific loons by excluding them from potential breeding lakes. Pacific loon occupancy was conditional on the presence of yellow-billed loons, with Pacific loons having almost a tenfold decrease in occupancy probability when yellow-billed loons were present and a threefold decrease in colonization probability when yellow-billed loons were present in the current or previous year. Yellow-billed and Pacific loons co-occurred less than expected by chance except on very large lakes or lakes with convoluted shorelines; variables which may decrease the cost of maintaining a territory in the presence of the other species. These results imply the existence of interspecific competition between yellow-billed and Pacific loons for nesting lakes; however, habitat characteristics which facilitate visual and spatial separation of territories can reduce competitive interactions and promote species co-occurrence.

  13. Sex allocation promotes the stable co-occurrence of competitive species

    Science.gov (United States)

    Kobayashi, Kazuya

    2017-03-01

    Biodiversity has long been a source of wonder and scientific curiosity. Theoretically, the co-occurrence of competitive species requires niche differentiation, and such differences are well known; however, the neutral theory, which assumes the equivalence of all individuals regardless of the species in a biological community, has successfully recreated observed patterns of biodiversity. In this research, the evolution of sex allocation is demonstrated to be the key to resolving why the neutral theory works well, despite the observed species differences. The sex allocation theory predicts that female-biased allocation evolves in species in declining density and that this allocation improves population growth, which should lead to an increase in density. In contrast, when the density increases, a less biased allocation evolves, which reduces the population growth rate and leads to decreased density. Thus, sex allocation provides a buffer against species differences in population growth. A model incorporating this mechanism demonstrates that hundreds of species can co-occur over 10,000 generations, even in homogeneous environments, and reproduces the observed patterns of biodiversity. This study reveals the importance of evolutionary processes within species for the sustainability of biodiversity. Integrating the entire biological process, from genes to community, will open a new era of ecology.

  14. The reflection of hierarchical cluster analysis of co-occurrence matrices in SPSS

    NARCIS (Netherlands)

    Zhou, Q.; Leng, F.; Leydesdorff, L.

    2015-01-01

    Purpose: To discuss the problems arising from hierarchical cluster analysis of co-occurrence matrices in SPSS, and the corresponding solutions. Design/methodology/approach: We design different methods of using the SPSS hierarchical clustering module for co-occurrence matrices in order to compare

  15. Quantity and quality limit detritivore growth: mechanisms revealed by ecological stoichiometry and co-limitation theory.

    Science.gov (United States)

    Halvorson, Halvor M; Sperfeld, Erik; Evans-White, Michelle A

    2017-12-01

    Resource quantity and quality are fundamental bottom-up constraints on consumers. Best understood in autotroph-based systems, co-occurrence of these constraints may be common but remains poorly studied in detrital-based systems. Here, we used a laboratory growth experiment to test limitation of the detritivorous caddisfly larvae Pycnopsyche lepida across a concurrent gradient of oak litter quantity (food supply) and quality (phosphorus : carbon [P:C ratios]). Growth increased simultaneously with quantity and quality, indicating co-limitation across the resource gradients. We merged approaches of ecological stoichiometry and co-limitation theory, showing how co-limitation reflected shifts in C and P acquisition throughout homeostatic regulation. Increased growth was best explained by elevated consumption rates and improved P assimilation, which both increased with elevated quantity and quality. Notably, C assimilation efficiencies remained unchanged and achieved maximum 18% at low quantity despite pronounced C limitation. Detrital C recalcitrance and substantive post-assimilatory C losses probably set a minimum quantity threshold to achieve positive C balance. Above this threshold, greater quality enhanced larval growth probably by improving P assimilation toward P-intensive growth. We suggest this interplay of C and P acquisition contributes to detritivore co-limitation, highlighting quantity and quality as potential simultaneous bottom-up controls in detrital-based ecosystems, including under anthropogenic change like nutrient enrichment. © 2017 by the Ecological Society of America.

  16. The Influence of Label Co-occurrence and Semantic Similarity on Children’s Inductive Generalization

    Directory of Open Access Journals (Sweden)

    Bryan J Matlen

    2015-08-01

    Full Text Available Semantically-similar labels that co-occur in child-directed speech (e.g., bunny-rabbit are more likely to promote inductive generalization in preschoolers than non-co-occurring labels (e.g., lamb-sheep. However, it remains unclear whether this effect stems from co-occurrence or other factors, and how co-occurrence contributes to generalization. To address these issues, preschoolers were exposed to a stream of semantically-similar labels that don’t co-occur in natural language, but were arranged to co-occur in the experimental setting. In Experiment 1, children exposed to the co-occurring stream were more likely to make category-consistent inferences than children in two control conditions. Experiment 2 replicated this effect and provided evidence that co-occurrence training influenced generalization only when the trained labels were categorically-similar. These findings suggest that both co-occurrence information and semantic representations contribute to preschool-age children’s inductive generalization. The findings are discussed in relation to the developmental accounts of inductive generalization.

  17. cooccurNet: an R package for co-occurrence network construction and analysis.

    Science.gov (United States)

    Zou, Yuanqiang; Wu, Zhiqiang; Deng, Lizong; Wu, Aiping; Wu, Fan; Li, Kenli; Jiang, Taijiao; Peng, Yousong

    2017-06-15

    Previously, we developed a computational model to identify genomic co-occurrence networks that was applied to capture the coevolution patterns within genomes of influenza viruses. To facilitate easy public use of this model, an R package 'cooccurNet' is presented here. 'cooccurNet' includes functionalities of construction and analysis of residues (e.g. nucleotides, amino acids and SNPs) co-occurrence network. In addition, a new method for measuring residues coevolution, defined as residue co-occurrence score (RCOS), is proposed and implemented in 'cooccurNet' based on the co-occurrence network. 'cooccurNet' is publicly available on CRAN repositories under the GPL-3 Open Source License ( http://cran.r-project.org/package=cooccurNet ). taijiao@ibms.pumc.edu.cn or pys2013@hnu.edu.cn. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  18. Co-introduction vs ecological fitting as pathways to the establishment of effective mutualisms during biological invasions.

    Science.gov (United States)

    Le Roux, Johannes J; Hui, Cang; Keet, Jan-Hendrik; Ellis, Allan G

    2017-09-01

    Contents 1354 I. 1354 II. 1355 III. 1357 IV. 1357 V. 1359 1359 References 1359 SUMMARY: Interactions between non-native plants and their mutualists are often disrupted upon introduction to new environments. Using legume-rhizobium mutualistic interactions as an example, we discuss two pathways that can influence symbiotic associations in such situations: co-introduction of coevolved rhizobia; and utilization of, and adaptation to, resident rhizobia, hereafter referred to as 'ecological fitting'. Co-introduction and ecological fitting have distinct implications for successful legume invasions and their impacts. Under ecological fitting, initial impacts may be less severe and will accrue over longer periods as novel symbiotic associations and/or adaptations may require fine-tuning over time. Co-introduction will have more profound impacts that will accrue more rapidly as a result of positive feedbacks between densities of non-native rhizobia and their coevolved host plants, in turn enhancing competition between native and non-native rhizobia. Co-introduction can further impact invasion outcomes by the exchange of genetic material between native and non-native rhizobia, potentially resulting in decreased fitness of native legumes. A better understanding of the roles of these two pathways in the invasion dynamics of non-native legumes is much needed, and we highlight some of the exciting research avenues it presents. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  19. Co-occurrence patterns of trees along macro-climatic gradients and their potential influence on the present and future distribution of Fagus sylvatica L.

    Science.gov (United States)

    Meier, E.S.; Edwards, T.C.; Kienast, Felix; Dobbertin, M.; Zimmermann, N.E.

    2011-01-01

    Aim During recent and future climate change, shifts in large-scale species ranges are expected due to the hypothesized major role of climatic factors in regulating species distributions. The stress-gradient hypothesis suggests that biotic interactions may act as major constraints on species distributions under more favourable growing conditions, while climatic constraints may dominate under unfavourable conditions. We tested this hypothesis for one focal tree species having three major competitors using broad-scale environmental data. We evaluated the variation of species co-occurrence patterns in climate space and estimated the influence of these patterns on the distribution of the focal species for current and projected future climates.Location Europe.Methods We used ICP Forest Level 1 data as well as climatic, topographic and edaphic variables. First, correlations between the relative abundance of European beech (Fagus sylvatica) and three major competitor species (Picea abies, Pinus sylvestris and Quercus robur) were analysed in environmental space, and then projected to geographic space. Second, a sensitivity analysis was performed using generalized additive models (GAM) to evaluate where and how much the predicted F. sylvatica distribution varied under current and future climates if potential competitor species were included or excluded. We evaluated if these areas coincide with current species co-occurrence patterns.Results Correlation analyses supported the stress-gradient hypothesis: towards favourable growing conditions of F. sylvatica, its abundance was strongly linked to the abundance of its competitors, while this link weakened towards unfavourable growing conditions, with stronger correlations in the south and at low elevations than in the north and at high elevations. The sensitivity analysis showed a potential spatial segregation of species with changing climate and a pronounced shift of zones where co-occurrence patterns may play a major role

  20. Networks Depicting the Fine-Scale Co-Occurrences of Fungi in Soil Horizons.

    Science.gov (United States)

    Toju, Hirokazu; Kishida, Osamu; Katayama, Noboru; Takagi, Kentaro

    2016-01-01

    Fungi in soil play pivotal roles in nutrient cycling, pest controls, and plant community succession in terrestrial ecosystems. Despite the ecosystem functions provided by soil fungi, our knowledge of the assembly processes of belowground fungi has been limited. In particular, we still have limited knowledge of how diverse functional groups of fungi interact with each other in facilitative and competitive ways in soil. Based on the high-throughput sequencing data of fungi in a cool-temperate forest in northern Japan, we analyzed how taxonomically and functionally diverse fungi showed correlated fine-scale distributions in soil. By uncovering pairs of fungi that frequently co-occurred in the same soil samples, networks depicting fine-scale co-occurrences of fungi were inferred at the O (organic matter) and A (surface soil) horizons. The results then led to the working hypothesis that mycorrhizal, endophytic, saprotrophic, and pathogenic fungi could form compartmentalized (modular) networks of facilitative, antagonistic, and/or competitive interactions in belowground ecosystems. Overall, this study provides a research basis for further understanding how interspecific interactions, along with sharing of niches among fungi, drive the dynamics of poorly explored biospheres in soil.

  1. Evolutionary features of academic articles co-keyword network and keywords co-occurrence network: Based on two-mode affiliation network

    Science.gov (United States)

    Li, Huajiao; An, Haizhong; Wang, Yue; Huang, Jiachen; Gao, Xiangyun

    2016-05-01

    Keeping abreast of trends in the articles and rapidly grasping a body of article's key points and relationship from a holistic perspective is a new challenge in both literature research and text mining. As the important component, keywords can present the core idea of the academic article. Usually, articles on a single theme or area could share one or some same keywords, and we can analyze topological features and evolution of the articles co-keyword networks and keywords co-occurrence networks to realize the in-depth analysis of the articles. This paper seeks to integrate statistics, text mining, complex networks and visualization to analyze all of the academic articles on one given theme, complex network(s). All 5944 ;complex networks; articles that were published between 1990 and 2013 and are available on the Web of Science are extracted. Based on the two-mode affiliation network theory, a new frontier of complex networks, we constructed two different networks, one taking the articles as nodes, the co-keyword relationships as edges and the quantity of co-keywords as the weight to construct articles co-keyword network, and another taking the articles' keywords as nodes, the co-occurrence relationships as edges and the quantity of simultaneous co-occurrences as the weight to construct keyword co-occurrence network. An integrated method for analyzing the topological features and evolution of the articles co-keyword network and keywords co-occurrence networks is proposed, and we also defined a new function to measure the innovation coefficient of the articles in annual level. This paper provides a useful tool and process for successfully achieving in-depth analysis and rapid understanding of the trends and relationships of articles in a holistic perspective.

  2. Co-occurrence perspective of arsenic and fluoride in the groundwater of Diphu, Assam, Northeastern India.

    Science.gov (United States)

    Kumar, Manish; Das, Aparna; Das, Nilotpal; Goswami, Ritusmita; Singh, Umesh Kumar

    2016-05-01

    Considerable lacunae exists in As and F(-) co-contamination investigation in the Brahmaputra and Gangetic floodplains. Therefore we selected Diphu a township in the Karbi Plateau rising from the Brahmaputra floodplains for evaluation of As and F co-occurrence, correlation with coexisting ions of the aquifer system and elucidation of potential processes for releasing As and F(-) in the groundwater. Our initial appraisal used generic plots for identification of hydro geochemical processes and major water types. Subsequently, As and F(-) co-occurrence with pH, depth, HCO3(-), SO4(2-), Ca(2+) and Fe were probed for possible correlation followed by hierarchical cluster analyses to identify key processes for co-occurrence. Finally, saturation indices of groundwater minerals were calculated using MINTEQA2 to elucidate prospective As and F(-) release into groundwater. Results indicate F(-) and As presence in Ca-HCO3 rich water along with positive correlation between Ca(2+) and F(-) possibly due to limestone reserves in adjoining areas. Multivariate analyses suggest the presence of high concentrations of PO4(3-), and H4SiO4 either individually or in combination can enhance the mobility of both As and F(-) and possibly abet conditions conducive for co-contamination of aquifers. Initial release of As and F(-) from the parent rock seems driven by the anthropogenic activities while mobilization depends on chemical interactions and individual affinities of the elements. The results of speciation highlight further mobilization of As and F(-) into the groundwater which in turn require regular attention for sustainable management of scarce water resource present in the area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Co-occurrence of Local Anisotropic Gradient Orientations (CoLlAGe): A new radiomics descriptor.

    Science.gov (United States)

    Prasanna, Prateek; Tiwari, Pallavi; Madabhushi, Anant

    2016-11-22

    In this paper, we introduce a new radiomic descriptor, Co-occurrence of Local Anisotropic Gradient Orientations (CoLlAGe) for capturing subtle differences between benign and pathologic phenotypes which may be visually indistinguishable on routine anatomic imaging. CoLlAGe seeks to capture and exploit local anisotropic differences in voxel-level gradient orientations to distinguish similar appearing phenotypes. CoLlAGe involves assigning every image voxel an entropy value associated with the co-occurrence matrix of gradient orientations computed around every voxel. The hypothesis behind CoLlAGe is that benign and pathologic phenotypes even though they may appear similar on anatomic imaging, will differ in their local entropy patterns, in turn reflecting subtle local differences in tissue microarchitecture. We demonstrate CoLlAGe's utility in three clinically challenging classification problems: distinguishing (1) radiation necrosis, a benign yet confounding effect of radiation treatment, from recurrent tumors on T1-w MRI in 42 brain tumor patients, (2) different molecular sub-types of breast cancer on DCE-MRI in 65 studies and (3) non-small cell lung cancer (adenocarcinomas) from benign fungal infection (granulomas) on 120 non-contrast CT studies. For each of these classification problems, CoLlAGE in conjunction with a random forest classifier outperformed state of the art radiomic descriptors (Haralick, Gabor, Histogram of Gradient Orientations).

  4. Co-occurrence correlations of heavy metals in sediments revealed using network analysis.

    Science.gov (United States)

    Liu, Lili; Wang, Zhiping; Ju, Feng; Zhang, Tong

    2015-01-01

    In this study, the correlation-based study was used to identify the co-occurrence correlations among metals in marine sediment of Hong Kong, based on the long-term (from 1991 to 2011) temporal and spatial monitoring data. 14 stations out of the total 45 marine sediment monitoring stations were selected from three representative areas, including Deep Bay, Victoria Harbour and Mirs Bay. Firstly, Spearman's rank correlation-based network analysis was conducted as the first step to identify the co-occurrence correlations of metals from raw metadata, and then for further analysis using the normalized metadata. The correlations patterns obtained by network were consistent with those obtained by the other statistic normalization methods, including annual ratios, R-squared coefficient and Pearson correlation coefficient. Both Deep Bay and Victoria Harbour have been polluted by heavy metals, especially for Pb and Cu, which showed strong co-occurrence with other heavy metals (e.g. Cr, Ni, Zn and etc.) and little correlations with the reference parameters (Fe or Al). For Mirs Bay, which has better marine sediment quality compared with Deep Bay and Victoria Harbour, the co-occurrence patterns revealed by network analysis indicated that the metals in sediment dominantly followed the natural geography process. Besides the wide applications in biology, sociology and informatics, it is the first time to apply network analysis in the researches of environment pollutions. This study demonstrated its powerful application for revealing the co-occurrence correlations among heavy metals in marine sediments, which could be further applied for other pollutants in various environment systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Biotic Interactions Shape the Ecological Distributions of Staphylococcus Species.

    Science.gov (United States)

    Kastman, Erik K; Kamelamela, Noelani; Norville, Josh W; Cosetta, Casey M; Dutton, Rachel J; Wolfe, Benjamin E

    2016-10-18

    ) species, we demonstrate that fungi can mediate the ecological distributions of closely related bacterial species. One of the Staphylococcus species studied, S. saprophyticus, is a common cause of urinary tract infections. By identifying processes that control the abundance of undesirable CNS species, cheese producers will have more precise control on the safety and quality of their products. More generally, Staphylococcus species frequently co-occur with fungi in mammalian microbiomes, and similar bacterium-fungus interactions may structure bacterial diversity in these systems. Copyright © 2016 Kastman et al.

  6. Ecological imperatives for aquatic CO2-concentrating mechanisms.

    Science.gov (United States)

    Maberly, Stephen C; Gontero, Brigitte

    2017-06-01

    In aquatic environments, the concentration of inorganic carbon is spatially and temporally variable and CO2 can be substantially oversaturated or depleted. Depletion of CO2 plus low rates of diffusion cause inorganic carbon to be more limiting in aquatic than terrestrial environments, and the frequency of species with a CO2-concentrating mechanism (CCM), and their contribution to productivity, is correspondingly greater. Aquatic photoautotrophs may have biochemical or biophysical CCMs and exploit CO2 from the sediment or the atmosphere. Though partly constrained by phylogeny, CCM activity is related to environmental conditions. CCMs are absent or down-regulated when their increased energy costs, lower CO2 affinity, or altered mineral requirements outweigh their benefits. Aquatic CCMs are most widespread in environments with low CO2, high HCO3-, high pH, and high light. Freshwater species are generally less effective at inorganic carbon removal than marine species, but have a greater range of ability to remove carbon, matching the environmental variability in carbon availability. The diversity of CCMs in seagrasses and marine phytoplankton, and detailed mechanistic studies on larger aquatic photoautotrophs are understudied. Strengthening the links between ecology and CCMs will increase our understanding of the mechanisms underlying ecological success and will place mechanistic studies in a clearer ecological context. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Worldwide Occurrence of Mycotoxins in Cereals and Cereal-Derived Food Products: Public Health Perspectives of Their Co-occurrence.

    Science.gov (United States)

    Lee, Hyun Jung; Ryu, Dojin

    2017-08-23

    Cereal grains and their processed food products are frequently contaminated with mycotoxins. Among many, five major mycotoxins of aflatoxins, ochratoxins, fumonisins, deoxynivalenol, and zearalenone are of significant public health concern as they can cause adverse effects in humans. Being airborne or soilborne, the cosmopolitan nature of mycotoxigenic fungi contribute to the worldwide occurrence of mycotoxins. On the basis of the global occurrence data reported during the past 10 years, the incidences and maximum levels in raw cereal grains were 55% and 1642 μg/kg for aflatoxins, 29% and 1164 μg/kg for ochratoxin A, 61% and 71,121 μg/kg for fumonisins, 58% and 41,157 μg/kg, for deoxynivalenol, and 46% and 3049 μg/kg for zearalenone. The concentrations of mycotoxins tend to be lower in processed food products; the incidences varied depending on the individual mycotoxins, possibly due to the varying stability during processing and distribution of mycotoxins. It should be noted that more than one mycotoxin, produced by a single or several fungal species, may occur in various combinations in a given sample or food. Most studies reported additive or synergistic effects, suggesting that these mixtures may pose a significant threat to public health, particularly to infants and young children. Therefore, information on the co-occurrence of mycotoxins and their interactive toxicity is summarized in this paper.

  8. Topical video object discovery from key frames by modeling word co-occurrence prior.

    Science.gov (United States)

    Zhao, Gangqiang; Yuan, Junsong; Hua, Gang; Yang, Jiong

    2015-12-01

    A topical video object refers to an object, that is, frequently highlighted in a video. It could be, e.g., the product logo and the leading actor/actress in a TV commercial. We propose a topic model that incorporates a word co-occurrence prior for efficient discovery of topical video objects from a set of key frames. Previous work using topic models, such as latent Dirichelet allocation (LDA), for video object discovery often takes a bag-of-visual-words representation, which ignored important co-occurrence information among the local features. We show that such data driven co-occurrence information from bottom-up can conveniently be incorporated in LDA with a Gaussian Markov prior, which combines top-down probabilistic topic modeling with bottom-up priors in a unified model. Our experiments on challenging videos demonstrate that the proposed approach can discover different types of topical objects despite variations in scale, view-point, color and lighting changes, or even partial occlusions. The efficacy of the co-occurrence prior is clearly demonstrated when compared with topic models without such priors.

  9. Specific non-monotonous interactions increase persistence of ecological networks.

    Science.gov (United States)

    Yan, Chuan; Zhang, Zhibin

    2014-03-22

    The relationship between stability and biodiversity has long been debated in ecology due to opposing empirical observations and theoretical predictions. Species interaction strength is often assumed to be monotonically related to population density, but the effects on stability of ecological networks of non-monotonous interactions that change signs have not been investigated previously. We demonstrate that for four kinds of non-monotonous interactions, shifting signs to negative or neutral interactions at high population density increases persistence (a measure of stability) of ecological networks, while for the other two kinds of non-monotonous interactions shifting signs to positive interactions at high population density decreases persistence of networks. Our results reveal a novel mechanism of network stabilization caused by specific non-monotonous interaction types through either increasing stable equilibrium points or reducing unstable equilibrium points (or both). These specific non-monotonous interactions may be important in maintaining stable and complex ecological networks, as well as other networks such as genes, neurons, the internet and human societies.

  10. Ecological interactions drive evolutionary loss of traits.

    Science.gov (United States)

    Ellers, Jacintha; Kiers, E Toby; Currie, Cameron R; McDonald, Bradon R; Visser, Bertanne

    2012-10-01

    Loss of traits can dramatically alter the fate of species. Evidence is rapidly accumulating that the prevalence of trait loss is grossly underestimated. New findings demonstrate that traits can be lost without affecting the external phenotype, provided the lost function is compensated for by species interactions. This is important because trait loss can tighten the ecological relationship between partners, affecting the maintenance of species interactions. Here, we develop a new perspective on so-called `compensated trait loss' and how this type of trait loss may affect the evolutionary dynamics between interacting organisms. We argue that: (1) the frequency of compensated trait loss is currently underestimated because it can go unnoticed as long as ecological interactions are maintained; (2) by analysing known cases of trait loss, specific factors promoting compensated trait loss can be identified and (3) genomic sequencing is a key way forwards in detecting compensated trait loss. We present a comprehensive literature survey showing that compensated trait loss is taxonomically widespread, can involve essential traits, and often occurs as replicated evolutionary events. Despite its hidden nature, compensated trait loss is important in directing evolutionary dynamics of ecological relationships and has the potential to change facultative ecological interactions into obligatory ones. © 2012 Blackwell Publishing Ltd/CNRS.

  11. CO2 leakage alters biogeochemical and ecological functions of submarine sands

    Science.gov (United States)

    Molari, Massimiliano; Guilini, Katja; Lott, Christian; Weber, Miriam; de Beer, Dirk; Meyer, Stefanie; Ramette, Alban; Wegener, Gunter; Wenzhöfer, Frank; Martin, Daniel; Cibic, Tamara; De Vittor, Cinzia; Vanreusel, Ann; Boetius, Antje

    2018-01-01

    Subseabed CO2 storage is considered a future climate change mitigation technology. We investigated the ecological consequences of CO2 leakage for a marine benthic ecosystem. For the first time with a multidisciplinary integrated study, we tested hypotheses derived from a meta-analysis of previous experimental and in situ high-CO2 impact studies. For this, we compared ecological functions of naturally CO2-vented seafloor off the Mediterranean island Panarea (Tyrrhenian Sea, Italy) to those of nonvented sands, with a focus on biogeochemical processes and microbial and faunal community composition. High CO2 fluxes (up to 4 to 7 mol CO2 m−2 hour−1) dissolved all sedimentary carbonate, and comigration of silicate and iron led to local increases of microphytobenthos productivity (+450%) and standing stocks (+300%). Despite the higher food availability, faunal biomass (−80%) and trophic diversity were substantially lower compared to those at the reference site. Bacterial communities were also structurally and functionally affected, most notably in the composition of heterotrophs and microbial sulfate reduction rates (−90%). The observed ecological effects of CO2 leakage on submarine sands were reproduced with medium-term transplant experiments. This study assesses indicators of environmental impact by CO2 leakage and finds that community compositions and important ecological functions are permanently altered under high CO2. PMID:29441359

  12. Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana

    OpenAIRE

    Wolf, Jason B.; Mutic, Joshua J.; Kover, Paula X.

    2011-01-01

    Studying the genetic basis of traits involved in ecological interactions is a fundamental part of elucidating the connections between evolutionary and ecological processes. Such knowledge allows one to link genetic models of trait evolution with ecological models describing interactions within and between species. Previous work has shown that connections between genetic and ecological processes in Arabidopsis thaliana may be mediated by the fact that quantitative trait loci (QTL) with ‘direct...

  13. Ecological turmoil in evolutionary dynamics of plant-insect interactions: defense to offence.

    Science.gov (United States)

    Mishra, Manasi; Lomate, Purushottam R; Joshi, Rakesh S; Punekar, Sachin A; Gupta, Vidya S; Giri, Ashok P

    2015-10-01

    Available history manifests contemporary diversity that exists in plant-insect interactions. A radical thinking is necessary for developing strategies that can co-opt natural insect-plant mutualism, ecology and environmental safety for crop protection since current agricultural practices can reduce species richness and evenness. The global environmental changes, such as increased temperature, CO₂ and ozone levels, biological invasions, land-use change and habitat fragmentation together play a significant role in re-shaping the plant-insect multi-trophic interactions. Diverse natural products need to be studied and explored for their biological functions as insect pest control agents. In order to assure the success of an integrated pest management strategy, human activities need to be harmonized to minimize the global climate changes. Plant-insect interaction is one of the most primitive and co-evolved associations, often influenced by surrounding changes. In this review, we account the persistence and evolution of plant-insect interactions, with particular focus on the effect of climate change and human interference on these interactions. Plants and insects have been maintaining their existence through a mutual service-resource relationship while defending themselves. We provide a comprehensive catalog of various defense strategies employed by the plants and/or insects. Furthermore, several important factors such as accelerated diversification, imbalance in the mutualism, and chemical arms race between plants and insects as indirect consequences of human practices are highlighted. Inappropriate implementation of several modern agricultural practices has resulted in (i) endangered mutualisms, (ii) pest status and resistance in insects and (iii) ecological instability. Moreover, altered environmental conditions eventually triggered the resetting of plant-insect interactions. Hence, multitrophic approaches that can harmonize human activities and minimize their

  14. Communicative interactions involving plants: information, evolution, and ecology.

    Science.gov (United States)

    Mescher, Mark C; Pearse, Ian S

    2016-08-01

    The role of information obtained via sensory cues and signals in mediating the interactions of organisms with their biotic and abiotic environments has been a major focus of work on sensory and behavioral ecology. Information-mediated interactions also have important implications for broader ecological patterns emerging at the community and ecosystem levels that are only now beginning to be explored. Given the extent to which plants dominate the sensory landscapes of terrestrial ecosystems, information-mediated interactions involving plants should be a major focus of efforts to elucidate these broader patterns. Here we explore how such efforts might be enhanced by a clear understanding of information itself-a central and potentially unifying concept in biology that has nevertheless been the subject of considerable confusion-and of its relationship to adaptive evolution and ecology. We suggest that information-mediated interactions should be a key focus of efforts to more fully integrate evolutionary biology and ecology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Ecological interactions are evolutionarily conserved across the entire tree of life.

    Science.gov (United States)

    Gómez, José M; Verdú, Miguel; Perfectti, Francisco

    2010-06-17

    Ecological interactions are crucial to understanding both the ecology and the evolution of organisms. Because the phenotypic traits regulating species interactions are largely a legacy of their ancestors, it is widely assumed that ecological interactions are phylogenetically conserved, with closely related species interacting with similar partners. However, the existing empirical evidence is inadequate to appropriately evaluate the hypothesis of phylogenetic conservatism in ecological interactions, because it is both ecologically and taxonomically biased. In fact, most studies on the evolution of ecological interactions have focused on specialized organisms, such as some parasites or insect herbivores, belonging to a limited subset of the overall tree of life. Here we study the evolution of host use in a large and diverse group of interactions comprising both specialist and generalist acellular, unicellular and multicellular organisms. We show that, as previously found for specialized interactions, generalized interactions can be evolutionarily conserved. Significant phylogenetic conservatism of interaction patterns was equally likely to occur in symbiotic and non-symbiotic interactions, as well as in mutualistic and antagonistic interactions. Host-use differentiation among species was higher in phylogenetically conserved clades, irrespective of their generalization degree and taxonomic position within the tree of life. Our findings strongly suggest a shared pattern in the organization of biological systems through evolutionary time, mediated by marked conservatism of ecological interactions among taxa.

  16. 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.

  17. Fixed versus dynamic co-occurrence windows in TextRank term weights for information retrieval

    DEFF Research Database (Denmark)

    Lu, Wei; Cheng, Qikai; Lioma, Christina

    2012-01-01

    iteratively is a score for each vertex, i.e. a term weight, that can be used for information retrieval (IR) just like conventional term frequency based term weights. So far, when computing TextRank term weights over co-occurrence graphs, the window of term co-occurrence is always fixed. This work departs from...

  18. Ecological interactions and the Netflix problem

    Directory of Open Access Journals (Sweden)

    Philippe Desjardins-Proulx

    2017-08-01

    Full Text Available Species interactions are a key component of ecosystems but we generally have an incomplete picture of who-eats-who in a given community. Different techniques have been devised to predict species interactions using theoretical models or abundances. Here, we explore the K nearest neighbour approach, with a special emphasis on recommendation, along with a supervised machine learning technique. Recommenders are algorithms developed for companies like Netflix to predict whether a customer will like a product given the preferences of similar customers. These machine learning techniques are well-suited to study binary ecological interactions since they focus on positive-only data. By removing a prey from a predator, we find that recommenders can guess the missing prey around 50% of the times on the first try, with up to 881 possibilities. Traits do not improve significantly the results for the K nearest neighbour, although a simple test with a supervised learning approach (random forests show we can predict interactions with high accuracy using only three traits per species. This result shows that binary interactions can be predicted without regard to the ecological community given only three variables: body mass and two variables for the species’ phylogeny. These techniques are complementary, as recommenders can predict interactions in the absence of traits, using only information about other species’ interactions, while supervised learning algorithms such as random forests base their predictions on traits only but do not exploit other species’ interactions. Further work should focus on developing custom similarity measures specialized for ecology to improve the KNN algorithms and using richer data to capture indirect relationships between species.

  19. Ecological interactions and the Netflix problem.

    Science.gov (United States)

    Desjardins-Proulx, Philippe; Laigle, Idaline; Poisot, Timothée; Gravel, Dominique

    2017-01-01

    Species interactions are a key component of ecosystems but we generally have an incomplete picture of who-eats-who in a given community. Different techniques have been devised to predict species interactions using theoretical models or abundances. Here, we explore the K nearest neighbour approach, with a special emphasis on recommendation, along with a supervised machine learning technique. Recommenders are algorithms developed for companies like Netflix to predict whether a customer will like a product given the preferences of similar customers. These machine learning techniques are well-suited to study binary ecological interactions since they focus on positive-only data. By removing a prey from a predator, we find that recommenders can guess the missing prey around 50% of the times on the first try, with up to 881 possibilities. Traits do not improve significantly the results for the K nearest neighbour, although a simple test with a supervised learning approach (random forests) show we can predict interactions with high accuracy using only three traits per species. This result shows that binary interactions can be predicted without regard to the ecological community given only three variables: body mass and two variables for the species' phylogeny. These techniques are complementary, as recommenders can predict interactions in the absence of traits, using only information about other species' interactions, while supervised learning algorithms such as random forests base their predictions on traits only but do not exploit other species' interactions. Further work should focus on developing custom similarity measures specialized for ecology to improve the KNN algorithms and using richer data to capture indirect relationships between species.

  20. Extraction of temporal networks from term co-occurrences in online textual sources.

    Directory of Open Access Journals (Sweden)

    Marko Popović

    Full Text Available A stream of unstructured news can be a valuable source of hidden relations between different entities, such as financial institutions, countries, or persons. We present an approach to continuously collect online news, recognize relevant entities in them, and extract time-varying networks. The nodes of the network are the entities, and the links are their co-occurrences. We present a method to estimate the significance of co-occurrences, and a benchmark model against which their robustness is evaluated. The approach is applied to a large set of financial news, collected over a period of two years. The entities we consider are 50 countries which issue sovereign bonds, and which are insured by Credit Default Swaps (CDS in turn. We compare the country co-occurrence networks to the CDS networks constructed from the correlations between the CDS. The results show relatively small, but significant overlap between the networks extracted from the news and those from the CDS correlations.

  1. Phylogenetic fields through time: temporal dynamics of geographical co-occurrence and phylogenetic structure within species ranges.

    Science.gov (United States)

    Villalobos, Fabricio; Carotenuto, Francesco; Raia, Pasquale; Diniz-Filho, José Alexandre F

    2016-04-05

    Species co-occur with different sets of other species across their geographical distribution, which can be either closely or distantly related. Such co-occurrence patterns and their phylogenetic structure within individual species ranges represent what we call the species phylogenetic fields (PFs). These PFs allow investigation of the role of historical processes--speciation, extinction and dispersal--in shaping species co-occurrence patterns, in both extinct and extant species. Here, we investigate PFs of large mammalian species during the last 3 Myr, and how these correlate with trends in diversification rates. Using the fossil record, we evaluate species' distributional and co-occurrence patterns along with their phylogenetic structure. We apply a novel Bayesian framework on fossil occurrences to estimate diversification rates through time. Our findings highlight the effect of evolutionary processes and past climatic changes on species' distributions and co-occurrences. From the Late Pliocene to the Recent, mammal species seem to have responded in an individualistic manner to climate changes and diversification dynamics, co-occurring with different sets of species from different lineages across their geographical ranges. These findings stress the difficulty of forecasting potential effects of future climate changes on biodiversity. © 2016 The Author(s).

  2. The Co-Occurrence of Reading Disorder and ADHD: Epidemiology, Treatment, Psychosocial Impact, and Economic Burden

    Science.gov (United States)

    Sexton, Chris C.; Gelhorn, Heather L.; Bell, Jill A.; Classi, Peter M.

    2012-01-01

    The co-occurrence of reading disorder (RD) and attention-deficit/hyperactivity disorder (ADHD) has received increasing attention. This review summarizes the epidemiology, treatment strategies, psychosocial impact, and economic burden associated with the co-occurrence of these conditions. Common genetic and neuropsychological deficits may partially…

  3. Co-occurrence and associations of pain and fatigue in a community sample of Dutch adults.

    NARCIS (Netherlands)

    Creavin, S.T.; Dunn, K.M.; Mallen, C.D.; Nijrolder, I.; Windt, D.A.W.M. van der

    2010-01-01

    Widespread pain and chronic fatigue are common in the general population. Previous research has demonstrated co-occurrence of syndromes that are associated with pain and fatigue (fibromyalgia and chronic fatigue syndrome), but there is limited existing data on the co-occurrence of these symptoms in

  4. 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.

  5. Microbial interactions: ecology in a molecular perspective.

    Science.gov (United States)

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

    2016-12-01

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

  6. Co-occurrence of carbohydrate malabsorption and primary epiploic appendagitis

    Science.gov (United States)

    Schnedl, Wolfgang J; Kalmar, Peter; Mangge, Harald; Krause, Robert; Wallner-Liebmann, Sandra J

    2015-01-01

    Unspecific abdominal complaints including bloating and irregular bowel movements may be caused by carbohydrate malabsorption syndromes, e.g., lactose and fructose malabsorption. These symptoms were investigated with hydrogen (H2) breath tests and correlated to carbohydrate malabsorption. During performing these H2-breath tests the patient presented with an acute, localized, non-migratory pain in the left lower abdominal quadrant. Primary epiploic appendagitis is a rare cause of abdominal acute or subacute complaints and diagnosis of primary epiploic appendagitis (PEA) is made when computed tomography reveals a characteristic lesion. We report on a patient with co-occurrence of lactose and fructose malabsorption, which was treated successfully with a diet free of culprit carbohydrates, with PEA recovering without medication or surgical treatment within few days. Since the abdominal unspecific symptoms had been present for months, they appeared not to be correlated to the acute localized abdominal pain, therefore we speculate on a random co-occurrence of combined carbohydrate malabsorption and PEA. PMID:26401090

  7. Ecology and evolution of plant–pollinator interactions

    Science.gov (United States)

    Mitchell, Randall J.; Irwin, Rebecca E.; Flanagan, Rebecca J.; Karron, Jeffrey D.

    2009-01-01

    Background Some of the most exciting advances in pollination biology have resulted from interdisciplinary research combining ecological and evolutionary perspectives. For example, these two approaches have been essential for understanding the functional ecology of floral traits, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. However, as research in these and other areas has progressed, many pollination biologists have become more specialized in their research interests, focusing their attention on either evolutionary or ecological questions. We believe that the continuing vigour of a synthetic and interdisciplinary field like pollination biology depends on renewed connections between ecological and evolutionary approaches. Scope In this Viewpoint paper we highlight the application of ecological and evolutionary approaches to two themes in pollination biology: (1) links between pollinator behaviour and plant mating systems, and (2) generalization and specialization in pollination systems. We also describe how mathematical models and synthetic analyses have broadened our understanding of pollination biology, especially in human-modified landscapes. We conclude with several suggestions that we hope will stimulate future research. This Viewpoint also serves as the introduction to this Special Issue on the Ecology and Evolution of Plant–Pollinator Interactions. These papers provide inspiring examples of the synergy between evolutionary and ecological approaches, and offer glimpses of great accomplishments yet to come. PMID:19482881

  8. Ecology and evolution of plant-pollinator interactions.

    Science.gov (United States)

    Mitchell, Randall J; Irwin, Rebecca E; Flanagan, Rebecca J; Karron, Jeffrey D

    2009-06-01

    Some of the most exciting advances in pollination biology have resulted from interdisciplinary research combining ecological and evolutionary perspectives. For example, these two approaches have been essential for understanding the functional ecology of floral traits, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant-pollinator interactions. However, as research in these and other areas has progressed, many pollination biologists have become more specialized in their research interests, focusing their attention on either evolutionary or ecological questions. We believe that the continuing vigour of a synthetic and interdisciplinary field like pollination biology depends on renewed connections between ecological and evolutionary approaches. In this Viewpoint paper we highlight the application of ecological and evolutionary approaches to two themes in pollination biology: (1) links between pollinator behaviour and plant mating systems, and (2) generalization and specialization in pollination systems. We also describe how mathematical models and synthetic analyses have broadened our understanding of pollination biology, especially in human-modified landscapes. We conclude with several suggestions that we hope will stimulate future research. This Viewpoint also serves as the introduction to this Special Issue on the Ecology and Evolution of Plant-Pollinator Interactions. These papers provide inspiring examples of the synergy between evolutionary and ecological approaches, and offer glimpses of great accomplishments yet to come.

  9. Utilization and control of ecological interactions in polymicrobial infections and community-based microbial cell factories.

    Science.gov (United States)

    Wigneswaran, Vinoth; Amador, Cristina Isabel; Jelsbak, Lotte; Sternberg, Claus; Jelsbak, Lars

    2016-01-01

    Microbial activities are most often shaped by interactions between co-existing microbes within mixed-species communities. Dissection of the molecular mechanisms of species interactions within communities is a central issue in microbial ecology, and our ability to engineer and control microbial communities depends, to a large extent, on our knowledge of these interactions. This review highlights the recent advances regarding molecular characterization of microbe-microbe interactions that modulate community structure, activity, and stability, and aims to illustrate how these findings have helped us reach an engineering-level understanding of microbial communities in relation to both human health and industrial biotechnology.

  10. Using Co-Occurrence to Evaluate Belief Coherence in a Large Non Clinical Sample

    Science.gov (United States)

    Pechey, Rachel; Halligan, Peter

    2012-01-01

    Much of the recent neuropsychological literature on false beliefs (delusions) has tended to focus on individual or single beliefs, with few studies actually investigating the relationship or co-occurrence between different types of co-existing beliefs. Quine and Ullian proposed the hypothesis that our beliefs form an interconnected web in which the beliefs that make up that system must somehow “cohere” with one another and avoid cognitive dissonance. As such beliefs are unlikely to be encapsulated (i.e., exist in isolation from other beliefs). The aim of this preliminary study was to empirically evaluate the probability of belief co-occurrence as one indicator of coherence in a large sample of subjects involving three different thematic sets of beliefs (delusion-like, paranormal & religious, and societal/cultural). Results showed that the degree of belief co-endorsement between beliefs within thematic groupings was greater than random occurrence, lending support to Quine and Ullian’s coherentist account. Some associations, however, were relatively weak, providing for well-established examples of cognitive dissonance. PMID:23155383

  11. Using co-occurrence to evaluate belief coherence in a large non clinical sample.

    Directory of Open Access Journals (Sweden)

    Rachel Pechey

    Full Text Available Much of the recent neuropsychological literature on false beliefs (delusions has tended to focus on individual or single beliefs, with few studies actually investigating the relationship or co-occurrence between different types of co-existing beliefs. Quine and Ullian proposed the hypothesis that our beliefs form an interconnected web in which the beliefs that make up that system must somehow "cohere" with one another and avoid cognitive dissonance. As such beliefs are unlikely to be encapsulated (i.e., exist in isolation from other beliefs. The aim of this preliminary study was to empirically evaluate the probability of belief co-occurrence as one indicator of coherence in a large sample of subjects involving three different thematic sets of beliefs (delusion-like, paranormal & religious, and societal/cultural. Results showed that the degree of belief co-endorsement between beliefs within thematic groupings was greater than random occurrence, lending support to Quine and Ullian's coherentist account. Some associations, however, were relatively weak, providing for well-established examples of cognitive dissonance.

  12. The Collaborative Longitudinal Personality Disorders Study: baseline Axis I/II and II/II diagnostic co-occurrence.

    Science.gov (United States)

    McGlashan, T H; Grilo, C M; Skodol, A E; Gunderson, J G; Shea, M T; Morey, L C; Zanarini, M C; Stout, R L

    2000-10-01

    To describe baseline diagnostic co-occurrence in the Collaborative Longitudinal Personality Disorders Study. Six hundred and sixty-eight patients were reliably assessed with diagnostic interviews for DSM-IV Axis I and II disorders to create five groups: Schizotypal (STPD), Borderline (BPD), Avoidant (AVPD), Obsessive-Compulsive (OCPD) and Major Depressive Disorder (MDD) without personality disorder (PD). Mean number of Axis I lifetime diagnoses was 3.4; STPD and BPD groups had more diagnoses than AVPD, OCPD, and MDD groups. Significant Axis I co-occurrences emerged for Social Phobia/ AVPD, PTSD/BPD and Substance Use/BPD. Mean number of co-occurring PDs was 1.4; STPD had more than BPD group which had more than AVPD and OCPD groups. Significant PD co-occurrence emerged for: STPD/ Paranoid and Schizoid PDs, BPD with Antisocial and Dependent PDs, and lower frequency for OCPD/Antisocial PD. Diagnostic co-occurrences generally followed base rates, while significant departures resemble those of controlled literature.

  13. Discovering Multi-scale Co-occurrence Patterns of Asthma and Influenza with the Oak Ridge Bio-surveillance Toolkit

    Directory of Open Access Journals (Sweden)

    Arvind eRamanathan

    2015-08-01

    Full Text Available We describe a data-driven unsupervised machine learning approach to extract geo-temporal co-occurrence patterns of asthma and the flu from large-scale electronic healthcare reimbursement claims (eHRC datasets. Specifically, we examine the eHRC data from the 2009-2010 pandemic H1N1 influenza season and analyze whether different geographic regions within the United States (US showed an increase in co-occurrence patterns of the flu and asthma. Our analyses reveal that the temporal patterns extracted from the eHRC data show a distinct lag time between the peak incidence of the asthma and the flu. While the increased occurrence of asthma contributed to increased flu incidence during the pandemic, this co-occurrence is predominant for female patients. The geo-temporal patterns reveal that the co-occurrence of the flu and asthma are typically concentrated within the south-east US. Further, in agreement with previous studies, large urban areas (such as New York, Miami and Los Angeles exhibit co-occurrence patterns that suggest a peak incidence of asthma and flu significantly early in the spring and winter seasons. Together, our data-analytic approach, integrated within the Oak Ridge Bio-surveillance Toolkit platform, demonstrates how eHRC data can provide novel insights into co-occurring disease patterns.

  14. Detection of LSB+/-1 steganography based on co-occurrence matrix and bit plane clipping

    Science.gov (United States)

    Abolghasemi, Mojtaba; Aghaeinia, Hassan; Faez, Karim; Mehrabi, Mohammad Ali

    2010-01-01

    Spatial LSB+/-1 steganography changes smooth characteristics between adjoining pixels of the raw image. We present a novel steganalysis method for LSB+/-1 steganography based on feature vectors derived from the co-occurrence matrix in the spatial domain. We investigate how LSB+/-1 steganography affects the bit planes of an image and show that it changes more least significant bit (LSB) planes of it. The co-occurrence matrix is derived from an image in which some of its most significant bit planes are clipped. By this preprocessing, in addition to reducing the dimensions of the feature vector, the effects of embedding were also preserved. We compute the co-occurrence matrix in different directions and with different dependency and use the elements of the resulting co-occurrence matrix as features. This method is sensitive to the data embedding process. We use a Fisher linear discrimination (FLD) classifier and test our algorithm on different databases and embedding rates. We compare our scheme with the current LSB+/-1 steganalysis methods. It is shown that the proposed scheme outperforms the state-of-the-art methods in detecting the LSB+/-1 steganographic method for grayscale images.

  15. Review of relationships between grey-tone co-occurrence, semivariance, and autocorrelation based image texture analysis approaches

    NARCIS (Netherlands)

    Sanden, van der J.J.; Hoekman, D.H.

    2005-01-01

    In the present paper we review relationships between commonly used statistical approaches to analysis of image texture. The approaches considered characterize image texture by means of the statistics of grey- tone co- occurrence contrast, grey- tone co- occurrence correlation, semivariance, and

  16. Mutualistic interactions drive ecological niche convergence in a diverse butterfly community.

    Science.gov (United States)

    Elias, Marianne; Gompert, Zachariah; Jiggins, Chris; Willmott, Keith

    2008-12-02

    Ecological communities are structured in part by evolutionary interactions among their members. A number of recent studies incorporating phylogenetics into community ecology have upheld the paradigm that competition drives ecological divergence among species of the same guild. However, the role of other interspecific interactions, in particular positive interactions such as mutualism, remains poorly explored. We characterized the ecological niche and inferred phylogenetic relationships among members of a diverse community of neotropical Müllerian mimetic butterflies. Müllerian mimicry is one of the best studied examples of mutualism, in which unpalatable species converge in wing pattern locally to advertize their toxicity to predators. We provide evidence that mutualistic interactions can drive convergence along multiple ecological axes, outweighing both phylogeny and competition in shaping community structure. Our findings imply that ecological communities are adaptively assembled to a much greater degree than commonly suspected. In addition, our results show that phenotype and ecology are strongly linked and support the idea that mimicry can cause ecological speciation through multiple cascading effects on species' biology.

  17. Mutualistic interactions drive ecological niche convergence in a diverse butterfly community.

    Directory of Open Access Journals (Sweden)

    Marianne Elias

    2008-12-01

    Full Text Available Ecological communities are structured in part by evolutionary interactions among their members. A number of recent studies incorporating phylogenetics into community ecology have upheld the paradigm that competition drives ecological divergence among species of the same guild. However, the role of other interspecific interactions, in particular positive interactions such as mutualism, remains poorly explored. We characterized the ecological niche and inferred phylogenetic relationships among members of a diverse community of neotropical Müllerian mimetic butterflies. Müllerian mimicry is one of the best studied examples of mutualism, in which unpalatable species converge in wing pattern locally to advertize their toxicity to predators. We provide evidence that mutualistic interactions can drive convergence along multiple ecological axes, outweighing both phylogeny and competition in shaping community structure. Our findings imply that ecological communities are adaptively assembled to a much greater degree than commonly suspected. In addition, our results show that phenotype and ecology are strongly linked and support the idea that mimicry can cause ecological speciation through multiple cascading effects on species' biology.

  18. Co-Occurrence of Language and Behavioural Change in Frontotemporal Lobar Degeneration.

    Science.gov (United States)

    Harris, Jennifer M; Jones, Matthew; Gall, Claire; Richardson, Anna M T; Neary, David; du Plessis, Daniel; Pal, Piyali; Mann, David M A; Snowden, Julie S; Thompson, Jennifer C

    2016-01-01

    We aimed to evaluate the co-occurrence of language and behavioural impairment in patients with frontotemporal lobar degeneration (FTLD) spectrum pathology. Eighty-one dementia patients with pathological confirmation of FTLD were identified. Anonymized clinical records from patients' first assessment were rated for language and behavioural features from frontotemporal dementia consensus criteria, primary progressive aphasia (PPA) criteria and 1998 FTLD criteria. Over 90% of patients with FTLD pathology exhibited a combination of at least one behavioural and one language feature. Changes in language, in particular, were commonly accompanied by behavioural change. Notably, the majority of patients who displayed language features characteristic of semantic variant PPA exhibited 'early perseverative, stereotyped or compulsive/ritualistic behaviour'. Moreover, 'executive/generation deficits with relative sparing of memory and visuospatial functions' occurred in most patients with core features of non-fluent variant PPA. Behavioural and language symptoms frequently co-occur in patients with FTLD pathology. Current classifications, which separate behavioural and language syndromes, do not reflect this co-occurrence.

  19. Co-occurrence of gemination and dens invaginatus: a case report

    Directory of Open Access Journals (Sweden)

    Sonika Achalli

    2016-03-01

    Full Text Available Gemination is a developmental anomaly where a single tooth bud attempts to split into two. It is also sometimes called as double tooth or twinning. Dens invaginatus is another developmental anomaly caused due to invagination of a portion of crown. These anomalies occur as separate entities. Co-occurrence of these two anomalies have been only reported four times in the literature. Here we present an extremely rare case of simultaneous occurrence of gemination and dens invaginatus in the same tooth. [Cukurova Med J 2016; 41(1.000: 175-177

  20. Hypergraph-based anomaly detection of high-dimensional co-occurrences.

    Science.gov (United States)

    Silva, Jorge; Willett, Rebecca

    2009-03-01

    This paper addresses the problem of detecting anomalous multivariate co-occurrences using a limited number of unlabeled training observations. A novel method based on using a hypergraph representation of the data is proposed to deal with this very high-dimensional problem. Hypergraphs constitute an important extension of graphs which allow edges to connect more than two vertices simultaneously. A variational Expectation-Maximization algorithm for detecting anomalies directly on the hypergraph domain without any feature selection or dimensionality reduction is presented. The resulting estimate can be used to calculate a measure of anomalousness based on the False Discovery Rate. The algorithm has O(np) computational complexity, where n is the number of training observations and p is the number of potential participants in each co-occurrence event. This efficiency makes the method ideally suited for very high-dimensional settings, and requires no tuning, bandwidth or regularization parameters. The proposed approach is validated on both high-dimensional synthetic data and the Enron email database, where p > 75,000, and it is shown that it can outperform other state-of-the-art methods.

  1. Contemporary Ecological Interactions Improve Models of Past Trait Evolution.

    Science.gov (United States)

    Hutchinson, Matthew C; Gaiarsa, Marília P; Stouffer, Daniel B

    2018-02-20

    Despite the fact that natural selection underlies both traits and interactions, evolutionary models often neglect that ecological interactions may, and in many cases do, influence the evolution of traits. Here, we explore the interdependence of ecological interactions and functional traits in the pollination associations of hawkmoths and flowering plants. Specifically, we develop an adaptation of the Ornstein-Uhlenbeck model of trait evolution that allows us to study the influence of plant corolla depth and observed hawkmoth-plant interactions on the evolution of hawkmoth proboscis length. Across diverse modelling scenarios, we find that the inclusion of contemporary interactions can provide a better description of trait evolution than the null expectation. Moreover, we show that the pollination interactions provide more-likely models of hawkmoth trait evolution when interactions are considered at increasingly finescale groups of hawkmoths. Finally, we demonstrate how the results of best-fit modelling approaches can implicitly support the association between interactions and trait evolution that our method explicitly examines. In showing that contemporary interactions can provide insight into the historical evolution of hawkmoth proboscis length, we demonstrate the clear utility of incorporating additional ecological information to models designed to study past trait evolution.

  2. Interactions between ecology and economics

    OpenAIRE

    Bittig, Bernhard

    1983-01-01

    Interactions between economics and ecology are analyzed by means of a deductive approach as well as by means of an iteration model. Additional approaches are briefly touched upon, with the Black box approach being considered as particularly suitable. Finally, the limits of all thought models are defined.

  3. Precipitation alters interactions in a grassland ecological community.

    Science.gov (United States)

    Deguines, Nicolas; Brashares, Justin S; Prugh, Laura R

    2017-03-01

    Climate change is transforming precipitation regimes world-wide. Changes in precipitation regimes are known to have powerful effects on plant productivity, but the consequences of these shifts for the dynamics of ecological communities are poorly understood. This knowledge gap hinders our ability to anticipate and mitigate the impacts of climate change on biodiversity. Precipitation may affect fauna through direct effects on physiology, behaviour or demography, through plant-mediated indirect effects, or by modifying interactions among species. In this paper, we examined the response of a semi-arid ecological community to a fivefold change in precipitation over 7 years. We examined the effects of precipitation on the dynamics of a grassland ecosystem in central California from 2007 to 2013. We conducted vegetation surveys, pitfall trapping of invertebrates, visual surveys of lizards and capture-mark-recapture surveys of rodents on 30 plots each year. We used structural equation modelling to evaluate the direct, indirect and modifying effects of precipitation on plants, ants, beetles, orthopterans, kangaroo rats, ground squirrels and lizards. We found pervasive effects of precipitation on the ecological community. Although precipitation increased plant biomass, direct effects on fauna were often stronger than plant-mediated effects. In addition, precipitation altered the sign or strength of consumer-resource and facilitative interactions among the faunal community such that negative or neutral interactions became positive or vice versa with increasing precipitation. These findings indicate that precipitation influences ecological communities in multiple ways beyond its recognized effects on primary productivity. Stochastic variation in precipitation may weaken the average strength of biotic interactions over time, thereby increasing ecosystem stability and resilience to climate change. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological

  4. Co-occurrence Models in Music Genre Classification

    DEFF Research Database (Denmark)

    Ahrendt, Peter; Goutte, Cyril; Larsen, Jan

    2005-01-01

    Music genre classification has been investigated using many different methods, but most of them build on probabilistic models of feature vectors x\\_r which only represent the short time segment with index r of the song. Here, three different co-occurrence models are proposed which instead consider...... genre data set with a variety of modern music. The basis was a so-called AR feature representation of the music. Besides the benefit of having proper probabilistic models of the whole song, the lowest classification test errors were found using one of the proposed models....

  5. T-2 toxin and HT-2 toxin in grain and grain-based commodities in Europe: occurrence, factors affecting occurrence, co-occurence and toxicological effects

    NARCIS (Netherlands)

    Fels-Klerx, van der H.J.; Stratakou, I.

    2010-01-01

    This paper presents an overview of the occurrence of T-2 toxin and HT-2 toxin in cereals in Europe and derived food products, factors influencing the occurrence, co-occurrence with other trichothecenes, and toxicological effects of T-2 and HT-2 in human. Of all cereals, oats showed to be most

  6. Disentangling the co-structure of multilayer interaction networks: degree distribution and module composition in two-layer bipartite networks.

    Science.gov (United States)

    Astegiano, Julia; Altermatt, Florian; Massol, François

    2017-11-13

    Species establish different interactions (e.g. antagonistic, mutualistic) with multiple species, forming multilayer ecological networks. Disentangling network co-structure in multilayer networks is crucial to predict how biodiversity loss may affect the persistence of multispecies assemblages. Existing methods to analyse multilayer networks often fail to consider network co-structure. We present a new method to evaluate the modular co-structure of multilayer networks through the assessment of species degree co-distribution and network module composition. We focus on modular structure because of its high prevalence among ecological networks. We apply our method to two Lepidoptera-plant networks, one describing caterpillar-plant herbivory interactions and one representing adult Lepidoptera nectaring on flowers, thereby possibly pollinating them. More than 50% of the species established either herbivory or visitation interactions, but not both. These species were over-represented among plants and lepidopterans, and were present in most modules in both networks. Similarity in module composition between networks was high but not different from random expectations. Our method clearly delineates the importance of interpreting multilayer module composition similarity in the light of the constraints imposed by network structure to predict the potential indirect effects of species loss through interconnected modular networks.

  7. Significant Pairwise Co-occurrence Patterns Are Not the Rule in the Majority of Biotic Communities

    Directory of Open Access Journals (Sweden)

    Spyros Sfenthourakis

    2012-04-01

    Full Text Available Our aim was to investigate species co-occurrence patterns in a large number of published biotic communities, in order to document to what extent species associations can be found in presence-absence matrices. We also aim to compare and evaluate two metrics that focus on species pairs (the ‘natural’ and the ‘checkerboard’ metric using also artificial matrices. We applied the two metrics to many data sets from a huge variety of insular systems around the world. Both metrics reliably recover deviating species pairs and provide similar, albeit not identical, results. Nevertheless, only a few matrices exhibit significant deviations from random patterns, mostly vertebrates and higher plants. The benchmark cases cited in literature in favor of such assembly rules are indeed included in these exceptional cases. In conclusion, competitive or cooperative species interactions shaping communities cannot be inferred from patterns exhibited by presence-absence matrices. When such an analysis is attempted though, both the ‘natural’ and the ‘checkerboard’ metric should be set in a proper framework in order to provide useful insights regarding species associations. A large part of the discussion on species co-occurrence had originally been based on a few exceptional data sets that are not indicative of general patterns.

  8. Corpus Linguistics, Network Analysis and Co-occurrence Matrices Corpus Linguistics, Network Analysis and Co-occurrence Matrices

    Directory of Open Access Journals (Sweden)

    Keith Stuart

    2009-12-01

    Full Text Available This article describes research undertaken in order to design a methodology for the reticular representation of knowledge of a specific discourse community. To achieve this goal, a representative corpus of the scientific production of the members of this discourse community (Universidad Politécnica de Valencia, UPV was created. The article presents the practical analysis (frequency, keyword, collocation and cluster analysis that was carried out in the initial phases of the study aimed at establishing the theoretical and practical background and framework for our matrix and network analysis of the scientific discourse of the UPV. In the methodology section, the processes that have allowed us to extract from the corpus the linguistic elements needed to develop co-occurrence matrices, as well as the computer tools used in the research, are described. From these co-occurrence matrices, semantic networks of subject and discipline knowledge were generated. Finally, based on the results obtained, we suggest that it may be viable to extract and to represent the intellectual capital of an academic institution using corpus linguistics methods in combination with the formulations of network theory.En este artículo describimos la investigación que se ha desarrollado en el diseño de una metodología para la representación reticular del conocimiento que se genera en el seno de una institución a partir de un corpus representativo de la producción científica de los integrantes de dicha comunidad discursiva, la Universidad Politécnica de Valencia.. Para ello, presentamos las acciones que se realizaron en las fases iniciales del estudio encaminadas a establecer el marco teórico y práctico en el que se inscribe nuestro análisis. En la sección de metodología se describen las herramientas informáticas utilizadas, así como los procesos que nos permitieron disponer de aquellos elementos presentes en el corpus, que nos llevarían al desarrollo de

  9. 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…

  10. Ecological consequences of interactions between ants and honeydew-producing insects

    OpenAIRE

    Styrsky, John D; Eubanks, Micky D

    2006-01-01

    Interactions between ants and honeydew-producing hemipteran insects are abundant and widespread in arthropod food webs, yet their ecological consequences are very poorly known. Ant–hemipteran interactions have potentially broad ecological effects, because the presence of honeydew-producing hemipterans dramatically alters the abundance and predatory behaviour of ants on plants. We review several studies that investigate the consequences of ant–hemipteran interactions as ‘keystone interactions’...

  11. Co-occurrence and clustering of health conditions at age 11: cross-sectional findings from the Millennium Cohort Study

    Science.gov (United States)

    Hesketh, Kathryn R; Fagg, James; Muniz-Terrera, Graciela; Law, Catherine; Hope, Steven

    2016-01-01

    Objectives To identify patterns of co-occurrence and clustering of 6 common adverse health conditions in 11-year-old children and explore differences by sociodemographic factors. Design Nationally representative prospective cohort study. Setting Children born in the UK between 2000 and 2002. Participants 11 399 11-year-old singleton children for whom data on all 6 health conditions and sociodemographic information were available (complete cases). Main outcome measures Prevalence, co-occurrence and clustering of 6 common health conditions: wheeze; eczema; long-standing illness (excluding wheeze and eczema); injury; socioemotional difficulties (measured using Strengths and Difficulties Questionnaire) and unfavourable weight (thin/overweight/obese vs normal). Results 42.4% of children had 2 or more adverse health conditions (co-occurrence). Co-occurrence was more common in boys and children from lower income households. Latent class analysis identified 6 classes: ‘normative’ (57.4%): ‘atopic burdened’ (14.0%); ‘socioemotional burdened’ (11.0%); ‘unfavourable weight/injury’ (7.7%); ‘eczema/injury’ (6.0%) and ‘eczema/unfavourable weight’ (3.9%). As with co-occurrence, class membership differed by sociodemographic factors: boys, children of mothers with lower educational attainment and children from lower income households were more likely to be in the ‘socioemotional burdened’ class. Children of mothers with higher educational attainment were more likely to be in the ‘normative’ and ‘eczema/unfavourable weight’ classes. Conclusions Co-occurrence of adverse health conditions at age 11 is common and is associated with adverse socioeconomic circumstances. Holistic, child focused care, particularly in boys and those in lower income groups, may help to prevent and reduce co-occurrence in later childhood and adolescence. PMID:27881529

  12. Co-Occurrence of Language and Behavioural Change in Frontotemporal Lobar Degeneration

    Directory of Open Access Journals (Sweden)

    Jennifer M. Harris

    2016-06-01

    Full Text Available Background/Objectives: We aimed to evaluate the co-occurrence of language and behavioural impairment in patients with frontotemporal lobar degeneration (FTLD spectrum pathology. Methods: Eighty-one dementia patients with pathological confirmation of FTLD were identified. Anonymized clinical records from patients' first assessment were rated for language and behavioural features from frontotemporal dementia consensus criteria, primary progressive aphasia (PPA criteria and 1998 FTLD criteria. Results: Over 90% of patients with FTLD pathology exhibited a combination of at least one behavioural and one language feature. Changes in language, in particular, were commonly accompanied by behavioural change. Notably, the majority of patients who displayed language features characteristic of semantic variant PPA exhibited ‘early perseverative, stereotyped or compulsive/ritualistic behaviour'. Moreover, ‘executive/generation deficits with relative sparing of memory and visuospatial functions' occurred in most patients with core features of non-fluent variant PPA. Conclusion: Behavioural and language symptoms frequently co-occur in patients with FTLD pathology. Current classifications, which separate behavioural and language syndromes, do not reflect this co-occurrence.

  13. On the relationship between positive and negative affect: Their correlation and their co-occurrence.

    Science.gov (United States)

    Larsen, Jeff T; Hershfield, Hal E; Stastny, Bradley J; Hester, Neil

    2017-03-01

    Understanding the nature of emotional experience requires understanding the relationship between positive and negative affect. Two particularly important aspects of that relationship are the extent to which positive and negative affect are correlated with one another and the extent to which they co-occur. Some researchers have assumed that weak negative correlations imply greater co-occurrence (i.e., more mixed emotions) than do strong negative correlations, but others have noted that correlations may imply very little about co-occurrence. We investigated the relationship between the correlation between positive and negative affect and co-occurrence. Participants in each of 2 samples provided moment-to-moment happiness and sadness ratings as they watched an evocative film and listened to music. Results indicated (a) that 4 measures of the correlation between positive and negative affect were quite highly related to 1 another; (b) that the strength of the correlation between measures of mixed emotions varied considerably; (c) that correlational measures were generally (but not always) weakly correlated with mixed emotion measures; and (d) that bittersweet stimuli consistently led to elevations in mixed emotion measures but did not consistently weaken the correlation between positive and negative affect. Results highlight that the correlation between positive and negative affect and their co-occurrence are distinct aspects of the relationship between positive and negative affect. Such insight helps clarify the implications of existing work on age-related and cultural differences in emotional experience and sets the stage for greater understanding of the experience of mixed emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Modeling Geometric-Temporal Context With Directional Pyramid Co-Occurrence for Action Recognition.

    Science.gov (United States)

    Yuan, Chunfeng; Li, Xi; Hu, Weiming; Ling, Haibin; Maybank, Stephen J

    2014-02-01

    In this paper, we present a new geometric-temporal representation for visual action recognition based on local spatio-temporal features. First, we propose a modified covariance descriptor under the log-Euclidean Riemannian metric to represent the spatio-temporal cuboids detected in the video sequences. Compared with previously proposed covariance descriptors, our descriptor can be measured and clustered in Euclidian space. Second, to capture the geometric-temporal contextual information, we construct a directional pyramid co-occurrence matrix (DPCM) to describe the spatio-temporal distribution of the vector-quantized local feature descriptors extracted from a video. DPCM characterizes the co-occurrence statistics of local features as well as the spatio-temporal positional relationships among the concurrent features. These statistics provide strong descriptive power for action recognition. To use DPCM for action recognition, we propose a directional pyramid co-occurrence matching kernel to measure the similarity of videos. The proposed method achieves the state-of-the-art performance and improves on the recognition performance of the bag-of-visual-words (BOVWs) models by a large margin on six public data sets. For example, on the KTH data set, it achieves 98.78% accuracy while the BOVW approach only achieves 88.06%. On both Weizmann and UCF CIL data sets, the highest possible accuracy of 100% is achieved.

  15. A study on the diagnosis of mild cognitive impairment using a co-occurrence matrix

    International Nuclear Information System (INIS)

    Kodama, Naoki; Shimada, Tetsuo; Kaeriyama, Tomoharu; Kaneko, Tomoyuki; Fukumoto, Ichiro

    2004-01-01

    We studied the possibility of making an objective diagnosis of mild cognitive impairment. An image of the cerebral parenchyma was created from original MR images, and the brain, hippocampus, parahippocampal gyrus, and the amount of the features from the co-occurrence matrix were measured. When the brain-intracranial ratio, hippocampus-intracranial ratio, and parahippocampal-intracranial ratio were computed, a significant difference was not detected. Discriminant analysis using the hippocampus-intracranial ratio and parahippocampal-intracranial ratio showed an overall accuracy of 63.8%. These are not sufficient results to use clinically. Therefore it is possible to make an objective diagnosis of mild cognitive impairment using the co-occurrence matrix. A statistically significant difference was found in 8 of the 13 features obtained from the co-occurrence matrix. Moreover, discriminant analysis using the eight features showed an overall accuracy of 85.1%. These results indicate that they can be used as an objective diagnostic technique for mild cognitive impairment. (author)

  16. How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence?

    Science.gov (United States)

    Király, Csilla; Szabó, Zsuzsanna; Szamosfalvi, Ágnes; Cseresznyés, Dóra; Király, Edit; Szabó, Csaba; Falus, György

    2017-04-01

    Carbon Capture and Storage (CCS) is a transitional technology to decrease CO2 emissions from human fossil fuel usage and, therefore, to mitigate climate change. The most important criteria of a CO2 geological storage reservoir is that it must hold the injected CO2 for geological time scales without its significant seepage. The injected CO2 undergoes physical and chemical reactions in the reservoir rocks such as structural-stratigraphic, residual, dissolution or mineral trapping mechanisms. Among these, the safest is the mineral trapping, when carbonate minerals such as calcite, ankerite, siderite, dolomite and dawsonite build the CO2 into their crystal structures. The study of natural CO2 occurrences may help to understand the processes in CO2 reservoirs on geological time scales. This is the reason why the selected, the Mihályi-Répcelak natural CO2 occurrence as our research area, which is able to provide particular and highly significant information for the future of CO2 storage. The area is one of the best known CO2 fields in Central Europe. The main aim of this study is to estimate the amount of CO2 trapped in the mineral phase at Mihályi-Répcelak CO2 reservoirs. For gaining the suitable data, we apply petrographic, major and trace element (microprobe and LA-ICP-MS) and stable isotope analysis (mass spectrometry) and thermodynamic and kinetic geochemical models coded in PHREEQC. Rock and pore water compositions of the same formation, representing the pre-CO2 flooding stages of the Mihályi-Répcelak natural CO2 reservoirs are used in the models. Kinetic rate parameters are derived from the USGS report of Palandri and Kharaka (2004). The results of petrographic analysis show that a significant amount of dawsonite (NaAlCO3(OH)2, max. 16 m/m%) precipitated in the rock due to its reactions with CO2 which flooded the reservoir. This carbonate mineral alone traps about 10-30 kg/m3 of the reservoir rock from the CO2 at Mihályi-Répcelak area, which is an

  17. Hierarchical structure of ecological and non-ecological processes of differentiation shaped ongoing gastropod radiation in the Malawi Basin.

    Science.gov (United States)

    Van Bocxlaer, Bert

    2017-09-13

    Ecological processes, non-ecological processes or a combination of both may cause reproductive isolation and speciation, but their specific roles and potentially complex interactions in evolutionary radiations remain poorly understood, which defines a central knowledge gap at the interface of microevolution and macroevolution. Here I examine genome scans in combination with phenotypic and environmental data to disentangle how ecological and non-ecological processes contributed to population differentiation and speciation in an ongoing radiation of Lanistes gastropods from the Malawi Basin. I found a remarkable hierarchical structure of differentiation mechanisms in space and time: neutral and mutation-order processes are older and occur mainly between regions, whereas more recent adaptive processes are the main driver of genetic differentiation and reproductive isolation within regions. The strongest differentiation occurs between habitats and between regions, i.e. when ecological and non-ecological processes act synergistically. The structured occurrence of these processes based on the specific geographical setting and ecological opportunities strongly influenced the potential for evolutionary radiation. The results highlight the importance of interactions between various mechanisms of differentiation in evolutionary radiations, and suggest that non-ecological processes are important in adaptive radiations, including those of cichlids. Insight into such interactions is critical to understanding large-scale patterns of organismal diversity. © 2017 The Author(s).

  18. Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana.

    Science.gov (United States)

    Wolf, Jason B; Mutic, Joshua J; Kover, Paula X

    2011-05-12

    Studying the genetic basis of traits involved in ecological interactions is a fundamental part of elucidating the connections between evolutionary and ecological processes. Such knowledge allows one to link genetic models of trait evolution with ecological models describing interactions within and between species. Previous work has shown that connections between genetic and ecological processes in Arabidopsis thaliana may be mediated by the fact that quantitative trait loci (QTL) with 'direct' effects on traits of individuals also have pleiotropic 'indirect' effects on traits expressed in neighbouring plants. Here, we further explore these connections by examining functional relationships between traits affected directly and indirectly by the same QTL. We develop a novel approach using structural equation models (SEMs) to determine whether observed pleiotropic effects result from traits directly affected by the QTL in focal individuals causing the changes in the neighbours' phenotypes. This hypothesis was assessed using SEMs to test whether focal plant phenotypes appear to mediate the connection between the focal plants' genotypes and the phenotypes of their neighbours, or alternatively, whether the connection between the focal plants' genotypes and the neighbours' phenotypes is mediated by unmeasured traits. We implement this analysis using a QTL of major effect that maps to the well-characterized flowering locus, FRIGIDA. The SEMs support the hypothesis that the pleiotropic indirect effects of this locus arise from size and developmental timing-related traits in focal plants affecting the expression of developmental traits in their neighbours. Our findings provide empirical insights into the genetics and nature of intraspecific ecological interactions. Our technique holds promise in directing future work into the genetic basis and functional relationship of traits mediating and responding to ecological interactions.

  19. PCDDs, PCDFs, and PCBs co-occurrence in TiO2 nanoparticles

    NARCIS (Netherlands)

    Ctistis, Georgios; Schön, Peter; Bakker, Wouter; Luthe, Gregor

    2016-01-01

    In the present study, we report on the co-occurrence of persistent organic pollutants (POPs) adsorbed on nanoparticular titanium dioxide (TiO2). We report on the finding of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) on the

  20. Interactive Videos Enhance Learning about Socio-Ecological Systems

    Science.gov (United States)

    Smithwick, Erica; Baxter, Emily; Kim, Kyung; Edel-Malizia, Stephanie; Rocco, Stevie; Blackstock, Dean

    2018-01-01

    Two forms of interactive video were assessed in an online course focused on conservation. The hypothesis was that interactive video enhances student perceptions about learning and improves mental models of social-ecological systems. Results showed that students reported greater learning and attitudes toward the subject following interactive video.…

  1. Asymmetric biotic interactions and abiotic niche differences revealed by a dynamic joint species distribution model.

    Science.gov (United States)

    Lany, Nina K; Zarnetske, Phoebe L; Schliep, Erin M; Schaeffer, Robert N; Orians, Colin M; Orwig, David A; Preisser, Evan L

    2018-05-01

    A species' distribution and abundance are determined by abiotic conditions and biotic interactions with other species in the community. Most species distribution models correlate the occurrence of a single species with environmental variables only, and leave out biotic interactions. To test the importance of biotic interactions on occurrence and abundance, we compared a multivariate spatiotemporal model of the joint abundance of two invasive insects that share a host plant, hemlock woolly adelgid (HWA; Adelges tsugae) and elongate hemlock scale (EHS; Fiorina externa), to independent models that do not account for dependence among co-occurring species. The joint model revealed that HWA responded more strongly to abiotic conditions than EHS. Additionally, HWA appeared to predispose stands to subsequent increase of EHS, but HWA abundance was not strongly dependent on EHS abundance. This study demonstrates how incorporating spatial and temporal dependence into a species distribution model can reveal the dependence of a species' abundance on other species in the community. Accounting for dependence among co-occurring species with a joint distribution model can also improve estimation of the abiotic niche for species affected by interspecific interactions. © 2018 by the Ecological Society of America.

  2. Ecological assembly rules in plant communities--approaches, patterns and prospects.

    Science.gov (United States)

    Götzenberger, Lars; de Bello, Francesco; Bråthen, Kari Anne; Davison, John; Dubuis, Anne; Guisan, Antoine; Lepš, Jan; Lindborg, Regina; Moora, Mari; Pärtel, Meelis; Pellissier, Loic; Pottier, Julien; Vittoz, Pascal; Zobel, Kristjan; Zobel, Martin

    2012-02-01

    Understanding how communities of living organisms assemble has been a central question in ecology since the early days of the discipline. Disentangling the different processes involved in community assembly is not only interesting in itself but also crucial for an understanding of how communities will behave under future environmental scenarios. The traditional concept of assembly rules reflects the notion that species do not co-occur randomly but are restricted in their co-occurrence by interspecific competition. This concept can be redefined in a more general framework where the co-occurrence of species is a product of chance, historical patterns of speciation and migration, dispersal, abiotic environmental factors, and biotic interactions, with none of these processes being mutually exclusive. Here we present a survey and meta-analyses of 59 papers that compare observed patterns in plant communities with null models simulating random patterns of species assembly. According to the type of data under study and the different methods that are applied to detect community assembly, we distinguish four main types of approach in the published literature: species co-occurrence, niche limitation, guild proportionality and limiting similarity. Results from our meta-analyses suggest that non-random co-occurrence of plant species is not a widespread phenomenon. However, whether this finding reflects the individualistic nature of plant communities or is caused by methodological shortcomings associated with the studies considered cannot be discerned from the available metadata. We advocate that more thorough surveys be conducted using a set of standardized methods to test for the existence of assembly rules in data sets spanning larger biological and geographical scales than have been considered until now. We underpin this general advice with guidelines that should be considered in future assembly rules research. This will enable us to draw more accurate and general

  3. Cophylogenetic signal is detectable in pollination interactions across ecological scales.

    Science.gov (United States)

    Hutchinson, Matthew C; Cagua, Edgar Fernando; Stouffer, Daniel B

    2017-10-01

    That evolutionary history can influence the way that species interact is a basic tenet of evolutionary ecology. However, when the role of evolution in determining ecological interactions is investigated, focus typically centers on just one side of the interaction. A cophylogenetic signal, the congruence of evolutionary history across both sides of an ecological interaction, extends these previous explorations and provides a more complete picture of how evolutionary patterns influence the way species interact. To date, cophylogenetic signal has most typically been studied in interactions that occur between fine taxonomic clades that show high intimacy. In this study, we took an alternative approach and made an exhaustive assessment of cophylogeny in pollination interactions. To do so, we assessed the strength of cophylogenetic signal at four distinct scales of pollination interaction: (1) across plant-pollinator associations globally, (2) in local pollination communities, (3) within the modular structure of those communities, and (4) in individual modules. We did so using a globally distributed dataset comprised of 54 pollination networks, over 4000 species, and over 12,000 interactions. Within these data, we detected cophylogenetic signal at all four scales. Cophylogenetic signal was found at the level of plant-pollinator interactions on a global scale and in the majority of pollination communities. At the scale defined by the modular structure within those communities, however, we observed a much weaker cophylogenetic signal. Cophylogenetic signal was detectable in a significant proportion of individual modules and most typically when within-module phylogenetic diversity was low. In sum, the detection of cophylogenetic signal in pollination interactions across scales provides a new dimension to the story of how past evolution shapes extant pollinator-angiosperm interactions. © 2017 by the Ecological Society of America.

  4. [Sexual violence and co-occurrences suffered by children and adolescents: study of incidents over a decade].

    Science.gov (United States)

    de Oliveira, Jacqueline Reiter; Costa, Maria Conceição Oliveira; Amaral, Magali Teresópolis Reis; Santos, Clarice Alves; de Assis, Simone Gonçalves; do Nascimento, Ohana Cunha

    2014-03-01

    The study analyzes the evolution of the incidence of sexual violence (SV) and co-occurrences between 2001 and 2010. The records of the Guardianship Councils in Feira de Santana, State of Bahia, Brazil were used and the incidence rates and graphs of the events during the period were calculated. Of the total of the different types of violence, 21.8 % involved co-occurrences, the majority being female, most frequently during adolescence. There was a high proportion of abuse in male children, with most offenders bring family members or acquaintances. The incidence of SV revealed an increasing trend in both sexes during the decade, more significantly in females in 2002 and 2009. The age groups indicated the same trend, with a higher proportion of cases in adolescence. The record of co-occurrences with SV was more pronounced in the second half of the decade, namely psychological violence in 2008, neglect in 2008 and physical violence in 2009. The conclusion is that the increase in the coefficients of sexual violence and co-occurrences may indicate an improvement of the reporting system of instances in reference, as well as greater citizen participation through the Dial 100 complaint hotline. The indicators help to prevent and control violence against children.

  5. Ecological Interactions between Humans, Wildlife Viral Reservoirs, and Key Environmental Drivers of Hantaan Virus Transmission

    Directory of Open Access Journals (Sweden)

    Xin Tong

    2017-10-01

    Full Text Available The occurrence and transmission of hemorrhagic fever with renal syndrome (HFRS are closely related to environmental variability, so it is essential to clarify the complex relationships among the environment, hantavirus transmission, and the population dynamics of its wildlife hosts. Tian et al. analyzed a large, long-term dataset describing the circulation of hantavirus in rodents and its spillover into humans. Their article incorporates several mathematical models and argues that the interaction between environmental and human behavioral factors drives the observed seasonality and interannual variations in important zoonotic diseases. The ecological cascade effect of a drought in 2002 is highlighted, and the role of seasonality in agricultural activity is emphasized in that study.

  6. At-risk depressive symptoms and alcohol use trajectories in adolescence: a person-centred analysis of co-occurrence.

    Science.gov (United States)

    Willoughby, Teena; Fortner, Adrian

    2015-04-01

    Long-term longitudinal studies that examine whether there are distinct trajectories of at-risk depressive symptoms and alcohol use across the high school years (e.g., high co-occurrence) are rare in normative samples of adolescent boys and girls; yet, this assessment is of critical importance for developing effective prevention and intervention strategies. Moreover, the role of self-regulation and novelty-seeking behavior in differentiating among distinct subgroups of adolescents is not clear. To address these gaps, the present study sought to identify subgroups of adolescent boys and girls that indicated at-risk trajectories across the high school years for both depressive symptoms and alcohol use, and examined the role of delay of gratification and novelty seeking at baseline in differentiating among the subgroups. Canadian adolescents (N = 4,412; 49 % female) were surveyed at four time points (grades 9, 10, 11, and 12). Parallel process latent class growth analyses revealed four distinct subgroups for both boys and girls, encompassing high co-occurrence, depressive symptoms only, alcohol use only, and low co-occurrence. Across gender, delay of gratification at baseline differentiated among the four subgroups, with the High Co-Occurrence Group group scoring the lowest and the Low Co-Occurrence Group the highest. Lower novelty-seeking scores at baseline were associated more with being in the Depressive Symptoms Only Group relative to the other groups, particularly the Alcohol Use Only Group for boys. Thus, delay of gratification and novelty seeking may be useful in identifying youth at risk for co-occurring depressive symptoms and alcohol use trajectories, as well as at-risk trajectories for only one of these behaviors.

  7. A multilayer network analysis of hashtags in twitter via co-occurrence and semantic links

    Science.gov (United States)

    Türker, Ilker; Sulak, Eyüb Ekmel

    2018-02-01

    Complex network studies, as an interdisciplinary framework, span a large variety of subjects including social media. In social networks, several mechanisms generate miscellaneous structures like friendship networks, mention networks, tag networks, etc. Focusing on tag networks (namely, hashtags in twitter), we made a two-layer analysis of tag networks from a massive dataset of Twitter entries. The first layer is constructed by converting the co-occurrences of these tags in a single entry (tweet) into links, while the second layer is constructed converting the semantic relations of the tags into links. We observed that the universal properties of the real networks like small-world property, clustering and power-law distributions in various network parameters are also evident in the multilayer network of hashtags. Moreover, we outlined that co-occurrences of hashtags in tweets are mostly coupled with semantic relations, whereas a small number of semantically unrelated, therefore random links reduce node separation and network diameter in the co-occurrence network layer. Together with the degree distributions, the power-law consistencies of degree difference, edge weight and cosine similarity distributions in both layers are also appealing forms of Zipf’s law evident in nature.

  8. Predicting and detecting reciprocity between indirect ecological interactions and evolution.

    Science.gov (United States)

    Estes, James A; Brashares, Justin S; Power, Mary E

    2013-05-01

    Living nature can be thought of as a tapestry, defined not only by its constituent parts but also by how these parts are woven together. The weaving of this tapestry is a metaphor for species interactions, which can be divided into three broad classes: competitive, mutualistic, and consumptive. Direct interactions link together as more complex networks, for example, the joining of consumptive interactions into food webs. Food web dynamics are driven, in turn, by changes in the abundances of web members, whose numbers or biomass respond to bottom-up (resource limitation) and top-down (consumer limitation) forcing. The relative strengths of top-down and bottom-up forcing on the abundance of a given web member depend on its ecological context, including its topological position within the food web. Top-down effects by diverse consumers are nearly ubiquitous, in many cases influencing the structure and operation of ecosystems. While the ecological effects of such interactions are well known, far less is known of their evolutionary consequences. In this essay, we describe sundry consequences of these interaction chains on species and ecosystem processes, explain several known or suspected evolutionary effects of consumer-induced interaction chains, and identify areas where reciprocity between ecology and evolution involving the indirect effects of consumer-prey interaction chains might be further explored.

  9. Landscape Use and Co-Occurrence Patterns of Neotropical Spotted Cats

    Science.gov (United States)

    Nagy-Reis, Mariana B.; Nichols, James D.; Chiarello, Adriano G.; Ribeiro, Milton Cezar; Setz, Eleonore Z. F.

    2017-01-01

    Small felids influence ecosystem dynamics through prey and plant population changes. Although most of these species are threatened, they are accorded one of the lowest research efforts of all felids, and we lack basic information about them. Many felids occur in sympatry, where intraguild competition is frequent. Therefore, assessing the role of interspecific interactions along with the relative importance of landscape characteristics is necessary to understand how these species co-occur in space. Here, we selected three morphologically similar and closely related species of small Neotropical cats to evaluate the roles of interspecific interactions, geomorphometry, environmental, and anthropogenic landscape characteristics on their habitat use. We collected data with camera trapping and scat sampling in a large protected Atlantic forest remnant (35,000 ha). Throughout occupancy modeling we investigated whether these species occur together more or less frequently than would be expected by chance, while dealing with imperfect detection and incorporating possible habitat preferences into the models. We used occupancy as a measure of their habitat use. Although intraguild competition can be an important determinant of carnivore assemblages, in our system, we did not find evidence that one species affects the habitat use of the other. Evidence suggested that proximity to the nature reserve (a more protected area) was a more important driver of Neotropical spotted cats’ occurrence than interspecific interactions or geomorphometry and environmental landscape characteristics—even though our entire study area is under some type of protection. This suggests that small felids can be sensitive to the area protection status, emphasizing the importance of maintaining and creating reserves and other areas with elevated protection for the proper management and conservation of the group. PMID:28052073

  10. Occurrence, composition and ecological restoration of organic pollutants in water environment of South Canal, China

    Science.gov (United States)

    Wang, Y. Z.; Lin, C.; Zhou, X. S.; Zhang, Y.; Han, C. G.

    2017-08-01

    Ecological restoration of polluted river water was carried out in South Canal by adding microbial water purifying agents and biological compound enzymes. The objective of present study was to investigate the ecological restoration effect of organic pollutants by this efficient immobilized microbial technologies, analysis the occurrence and composition of organic pollutants including fifteen persistent organochlorine pesticides (OCPs), seventeen polycyclic aromatic hydrocarbons (PAHs) and eighteen organophosphorus pesticides (OPPs) both in natural water environment and ecological restoration area of South Canal, China. Results showed that the total concentrations of OCPs ranged from 1.11 to 1.78 ng·L-1, PAHs from 52.76 to 60.28 ng·L-1, and OPPs from 6.51 to 17.50 ng·L-1. Microbial water purifying agents and biological compound enzymes essentially had no effects on biological degradation of OCPs and PAHs in the river, but could remove OPPs with degradation rates ranging from 19.6% to 62.8% (35.2% in average). Degradation mechanisms of microbial water purifying agents and biological compound enzymes on OCPs, PAHs and OPPs remained to be further studied. This technology has a certain value in practical ecological restoration of organic pollutants in rivers and lakes.

  11. Interactions between temperature and nutrients across levels of ecological organization.

    Science.gov (United States)

    Cross, Wyatt F; Hood, James M; Benstead, Jonathan P; Huryn, Alexander D; Nelson, Daniel

    2015-03-01

    Temperature and nutrient availability play key roles in controlling the pathways and rates at which energy and materials move through ecosystems. These factors have also changed dramatically on Earth over the past century as human activities have intensified. Although significant effort has been devoted to understanding the role of temperature and nutrients in isolation, less is known about how these two factors interact to influence ecological processes. Recent advances in ecological stoichiometry and metabolic ecology provide a useful framework for making progress in this area, but conceptual synthesis and review are needed to help catalyze additional research. Here, we examine known and potential interactions between temperature and nutrients from a variety of physiological, community, and ecosystem perspectives. We first review patterns at the level of the individual, focusing on four traits--growth, respiration, body size, and elemental content--that should theoretically govern how temperature and nutrients interact to influence higher levels of biological organization. We next explore the interactive effects of temperature and nutrients on populations, communities, and food webs by synthesizing information related to community size spectra, biomass distributions, and elemental composition. We use metabolic theory to make predictions about how population-level secondary production should respond to interactions between temperature and resource supply, setting up qualitative predictions about the flows of energy and materials through metazoan food webs. Last, we examine how temperature-nutrient interactions influence processes at the whole-ecosystem level, focusing on apparent vs. intrinsic activation energies of ecosystem processes, how to represent temperature-nutrient interactions in ecosystem models, and patterns with respect to nutrient uptake and organic matter decomposition. We conclude that a better understanding of interactions between temperature and

  12. Genes, communities & invasive species: understanding the ecological and evolutionary dynamics of host-pathogen interactions.

    Science.gov (United States)

    Burdon, J J; Thrall, P H; Ericson, L

    2013-08-01

    Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. 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

  14. Type and Degree of Co-Occurrence of the Educational Communication in a Community of Inquiry

    Science.gov (United States)

    Gutiérrez-Santiuste, Elba; Gallego-Arrufat, María-Jesús

    2017-01-01

    The study analyzes the type and quantity of co-occurrence of social, cognitive, and teaching presence in a Community of Inquiry (CoI). Content analysis of the virtual educational communication shows units of analysis that must be assigned to more than one category. By crossing the categories of the CoI model, we observe that Social Presence is…

  15. Cracklike defects detection and sizing from co-occurrence matrices

    International Nuclear Information System (INIS)

    Moysan, J.; Benoist, P.; Magnin, I.

    1991-01-01

    The inspection of austenitic welds used in nuclear field with ultrasounds poses problems in interpretation: strong grain noise makes difficult the detection of the crack top and the crack bottom. Since corresponding echoes enable the defect sizing, defect sizing also becomes difficult. The formation of 2D images (BSCAN), and their processing enable an increase in the effectiveness of testing. We present a segmentation method, based on co-occurrence matrix, which separates defects zones and noise zones. Examples of segmentation improvement applied to artificial defects are presented

  16. Natural Co-Occurrence of Mycotoxins in Foods and Feeds and Their in vitro Combined Toxicological Effects.

    Science.gov (United States)

    Smith, Marie-Caroline; Madec, Stéphanie; Coton, Emmanuel; Hymery, Nolwenn

    2016-03-26

    Some foods and feeds are often contaminated by numerous mycotoxins, but most studies have focused on the occurrence and toxicology of a single mycotoxin. Regulations throughout the world do not consider the combined effects of mycotoxins. However, several surveys have reported the natural co-occurrence of mycotoxins from all over the world. Most of the published data has concerned the major mycotoxins aflatoxins (AFs), ochratoxin A (OTA), zearalenone (ZEA), fumonisins (FUM) and trichothecenes (TCTs), especially deoxynivalenol (DON). Concerning cereals and derived cereal product samples, among the 127 mycotoxin combinations described in the literature, AFs+FUM, DON+ZEA, AFs+OTA, and FUM+ZEA are the most observed. However, only a few studies specified the number of co-occurring mycotoxins with the percentage of the co-contaminated samples, as well as the main combinations found. Studies of mycotoxin combination toxicity showed antagonist, additive or synergic effects depending on the tested species, cell model or mixture, and were not necessarily time- or dose-dependent. This review summarizes the findings on mycotoxins and their co-occurrence in various foods and feeds from all over the world as well as in vitro experimental data on their combined toxicity.

  17. Prevalence, Co-Occurrence and Clustering of Lifestyle Risk Factors Among UK Men

    Directory of Open Access Journals (Sweden)

    Stephen Zwolinsky

    2017-01-01

    Full Text Available Objective: Men – more than women - engage in unhealthy lifestyle practices that place them at greater risk of developing non-communicable disease. This paper aims to explore the prevalence, co-occurrence and clustering of four core lifestyle risk factors and examine the socio demographic variation of their distribution, among men living in two central London boroughs. Method: A stratified street survey was undertaken with N=859 men. Prevalence odds ratios calculated risk factor clustering and a multinomial logistic regression model examined the socio-demographic variation. Results: Over 72% of men presented with combinations of lifestyle risk factors. Physical inactivity combined with a lack of fruit and vegetables was the most common combination. Co-occurrence was more prominent for unemployed, widowed, divorced/separated and white British men. Clustering was evident for adherence and non-adherence to UK health recommendations. Conclusion: Men may benefit from targeted health interventions that address multiple – rather than single – health related behaviours.

  18. Utilization and control of ecological interactions in polymicrobial infections and community-based microbial cell factories [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Vinoth Wigneswaran

    2016-03-01

    Full Text Available Microbial activities are most often shaped by interactions between co-existing microbes within mixed-species communities. Dissection of the molecular mechanisms of species interactions within communities is a central issue in microbial ecology, and our ability to engineer and control microbial communities depends, to a large extent, on our knowledge of these interactions. This review highlights the recent advances regarding molecular characterization of microbe-microbe interactions that modulate community structure, activity, and stability, and aims to illustrate how these findings have helped us reach an engineering-level understanding of microbial communities in relation to both human health and industrial biotechnology.

  19. Algae-bacteria interactions: Evolution, ecology and emerging applications.

    Science.gov (United States)

    Ramanan, Rishiram; Kim, Byung-Hyuk; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

    2016-01-01

    Algae and bacteria have coexisted ever since the early stages of evolution. This coevolution has revolutionized life on earth in many aspects. Algae and bacteria together influence ecosystems as varied as deep seas to lichens and represent all conceivable modes of interactions - from mutualism to parasitism. Several studies have shown that algae and bacteria synergistically affect each other's physiology and metabolism, a classic case being algae-roseobacter interaction. These interactions are ubiquitous and define the primary productivity in most ecosystems. In recent years, algae have received much attention for industrial exploitation but their interaction with bacteria is often considered a contamination during commercialization. A few recent studies have shown that bacteria not only enhance algal growth but also help in flocculation, both essential processes in algal biotechnology. Hence, there is a need to understand these interactions from an evolutionary and ecological standpoint, and integrate this understanding for industrial use. Here we reflect on the diversity of such relationships and their associated mechanisms, as well as the habitats that they mutually influence. This review also outlines the role of these interactions in key evolutionary events such as endosymbiosis, besides their ecological role in biogeochemical cycles. Finally, we focus on extending such studies on algal-bacterial interactions to various environmental and bio-technological applications. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Ecological recovery in ERA

    DEFF Research Database (Denmark)

    EFSA Scientific Committee (Scientific Committee); Topping, Christopher John

    2016-01-01

    knowledge and data retrieved from the literature. Finally, the information presented in this opinion was reviewed by experts from the relevant EFSA Panels, European risk assessment bodies and through an open consultation requesting input from stakeholders. A conceptual framework was developed to address...... recognises the importance of more integrated ERAs considering both the local and landscape scales, as well as the possible co-occurrence of multiple potential stressors that fall under the remit of EFSA, which are important when addressing ecological recovery. In this scientific opinion, the Scientific...... Committee gathered scientific knowledge on the potential for the recovery of non-target organisms for the further development of ERA. Current EFSA guidance documents and opinions were reviewed on how ecological recovery is addressed in ERA schemes. In addition, this scientific opinion is based on expert...

  1. Molecular Ecological Insights into Neotropical Bird-Tick Interactions.

    Directory of Open Access Journals (Sweden)

    Matthew J Miller

    Full Text Available In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna. Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology

  2. Molecular Ecological Insights into Neotropical Bird-Tick Interactions.

    Science.gov (United States)

    Miller, Matthew J; Esser, Helen J; Loaiza, Jose R; Herre, Edward Allen; Aguilar, Celestino; Quintero, Diomedes; Alvarez, Eric; Bermingham, Eldredge

    2016-01-01

    In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna). Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology and the dynamics of

  3. Limitations of a metabolic network-based reverse ecology method for inferring host-pathogen interactions.

    Science.gov (United States)

    Takemoto, Kazuhiro; Aie, Kazuki

    2017-05-25

    Host-pathogen interactions are important in a wide range of research fields. Given the importance of metabolic crosstalk between hosts and pathogens, a metabolic network-based reverse ecology method was proposed to infer these interactions. However, the validity of this method remains unclear because of the various explanations presented and the influence of potentially confounding factors that have thus far been neglected. We re-evaluated the importance of the reverse ecology method for evaluating host-pathogen interactions while statistically controlling for confounding effects using oxygen requirement, genome, metabolic network, and phylogeny data. Our data analyses showed that host-pathogen interactions were more strongly influenced by genome size, primary network parameters (e.g., number of edges), oxygen requirement, and phylogeny than the reserve ecology-based measures. These results indicate the limitations of the reverse ecology method; however, they do not discount the importance of adopting reverse ecology approaches altogether. Rather, we highlight the need for developing more suitable methods for inferring host-pathogen interactions and conducting more careful examinations of the relationships between metabolic networks and host-pathogen interactions.

  4. Exploiting automatically generated databases of traffic signs and road markings for contextual co-occurrence analysis

    Science.gov (United States)

    Hazelhoff, Lykele; Creusen, Ivo M.; Woudsma, Thomas; de With, Peter H. N.

    2015-11-01

    Combined databases of road markings and traffic signs provide a complete and full description of the present traffic legislation and instructions. Such databases contribute to efficient signage maintenance, improve navigation, and benefit autonomous driving vehicles. A system is presented for the automated creation of such combined databases, which additionally investigates the benefit of this combination for automated contextual placement analysis. This analysis involves verification of the co-occurrence of traffic signs and road markings to retrieve a list of potentially incorrectly signaled (and thus potentially unsafe) road situations. This co-occurrence verification is specifically explored for both pedestrian crossings and yield situations. Evaluations on 420 km of road have shown that individual detection of traffic signs and road markings denoting these road situations can be performed with accuracies of 98% and 85%, respectively. Combining both approaches shows that over 95% of the pedestrian crossings and give-way situations can be identified. An exploration toward additional co-occurrence analysis of signs and markings shows that inconsistently signaled situations can successfully be extracted, such that specific safety actions can be directed toward cases lacking signs or markings, while most consistently signaled situations can be omitted from this analysis.

  5. A novel method for morphological pleomorphism and heterogeneity quantitative measurement: Named cell feature level co-occurrence matrix.

    Science.gov (United States)

    Saito, Akira; Numata, Yasushi; Hamada, Takuya; Horisawa, Tomoyoshi; Cosatto, Eric; Graf, Hans-Peter; Kuroda, Masahiko; Yamamoto, Yoichiro

    2016-01-01

    Recent developments in molecular pathology and genetic/epigenetic analysis of cancer tissue have resulted in a marked increase in objective and measurable data. In comparison, the traditional morphological analysis approach to pathology diagnosis, which can connect these molecular data and clinical diagnosis, is still mostly subjective. Even though the advent and popularization of digital pathology has provided a boost to computer-aided diagnosis, some important pathological concepts still remain largely non-quantitative and their associated data measurements depend on the pathologist's sense and experience. Such features include pleomorphism and heterogeneity. In this paper, we propose a method for the objective measurement of pleomorphism and heterogeneity, using the cell-level co-occurrence matrix. Our method is based on the widely used Gray-level co-occurrence matrix (GLCM), where relations between neighboring pixel intensity levels are captured into a co-occurrence matrix, followed by the application of analysis functions such as Haralick features. In the pathological tissue image, through image processing techniques, each nucleus can be measured and each nucleus has its own measureable features like nucleus size, roundness, contour length, intra-nucleus texture data (GLCM is one of the methods). In GLCM each nucleus in the tissue image corresponds to one pixel. In this approach the most important point is how to define the neighborhood of each nucleus. We define three types of neighborhoods of a nucleus, then create the co-occurrence matrix and apply Haralick feature functions. In each image pleomorphism and heterogeneity are then determined quantitatively. For our method, one pixel corresponds to one nucleus feature, and we therefore named our method Cell Feature Level Co-occurrence Matrix (CFLCM). We tested this method for several nucleus features. CFLCM is showed as a useful quantitative method for pleomorphism and heterogeneity on histopathological image

  6. Co-occurrence of viruses and mosquitoes at the vectors' optimal climate range: An underestimated risk to temperate regions?

    Science.gov (United States)

    Blagrove, Marcus S C; Caminade, Cyril; Waldmann, Elisabeth; Sutton, Elizabeth R; Wardeh, Maya; Baylis, Matthew

    2017-06-01

    Mosquito-borne viruses have been estimated to cause over 100 million cases of human disease annually. Many methodologies have been developed to help identify areas most at risk from transmission of these viruses. However, generally, these methodologies focus predominantly on the effects of climate on either the vectors or the pathogens they spread, and do not consider the dynamic interaction between the optimal conditions for both vector and virus. Here, we use a new approach that considers the complex interplay between the optimal temperature for virus transmission, and the optimal climate for the mosquito vectors. Using published geolocated data we identified temperature and rainfall ranges in which a number of mosquito vectors have been observed to co-occur with West Nile virus, dengue virus or chikungunya virus. We then investigated whether the optimal climate for co-occurrence of vector and virus varies between "warmer" and "cooler" adapted vectors for the same virus. We found that different mosquito vectors co-occur with the same virus at different temperatures, despite significant overlap in vector temperature ranges. Specifically, we found that co-occurrence correlates with the optimal climatic conditions for the respective vector; cooler-adapted mosquitoes tend to co-occur with the same virus in cooler conditions than their warmer-adapted counterparts. We conclude that mosquitoes appear to be most able to transmit virus in the mosquitoes' optimal climate range, and hypothesise that this may be due to proportionally over-extended vector longevity, and other increased fitness attributes, within this optimal range. These results suggest that the threat posed by vector-competent mosquito species indigenous to temperate regions may have been underestimated, whilst the threat arising from invasive tropical vectors moving to cooler temperate regions may be overestimated.

  7. Chemical ecology of insects and tritrophic interactions

    International Nuclear Information System (INIS)

    Ahmad, F.; Aslam, M.; Razaq, M.

    2004-01-01

    This paper reviews the chemical ecology of insects to explain the role of semiochemicals in plant-herbivore, herbivore-carnivore and plant-carnivore interactions. The semiochemical, mediating tritrophic interactions may be produced by plants, herbivores or their natural enemies (carnivores). Some semiochemicals attract the herbivores and carnivores and mediate interaction among them, while on the other hand some repel them. The semiochemicals are used by heribivores, parasites and predators as cues to locate food, host or prey. The same chemicals are also used for defensive purpose by some herbivores against their natural enemies as they are sequestered through their bodies. (author)

  8. Unifying relationships between complexity and stability in mutualistic ecological communities.

    Science.gov (United States)

    Feng, Wenfeng; Bailey, Richard M

    2018-02-14

    Conserving ecosystem function and associated services requires deep understanding of the underlying basis of system stability. While the study of ecological dynamics is a mature and diverse field, the lack of a general model that predicts a broad range of theoretical and empirical observations has allowed unresolved contradictions to persist. Here we provide a general model of mutualistic ecological interactions between two groups and show for the first time how the conditions for bi-stability, the nature of critical transitions, and identifiable leading indicators in time-series can be derived from the basic parameters describing the underlying ecological interactions. Strong mutualism and nonlinearity in handling-time are found to be necessary conditions for the occurrence of critical transitions. We use the model to resolve open questions concerning the effects of heterogeneity in inter-species interactions on both resilience and abundance, and discuss these in terms of potential trade-offs in real systems. This framework provides a basis for rich investigations of ecological system dynamics, and may be generalizable across many ecological contexts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Nonlinear disruption of ecological interactions in response to nitrogen deposition.

    Science.gov (United States)

    Ochoa-Hueso, Raúl

    2016-10-01

    Global environmental change (GEC) is affecting species interactions and causing a rapid decline in biodiversity. In this study, I present a new Ecosystem Disruption Index to quantify the impacts of simulated nitrogen (N) deposition (0, 10, 20, and 50 kg N·ha -1 ·yr -1  + 6-7 kg N·ha -1 ·yr -1 background) on abiotic and biotic ecological interactions. This comparative index is based on pairwise linear and quadratic regression matrices. These matrices, calculated at the N treatment level, were constructed using a range of abiotic and biotic ecosystem constituents: soil pH, shrub cover, and the first component of several separate principal component analyses using soil fertility data (total carbon and N) and community data (annual plants, microorganisms, biocrusts, edaphic fauna) for a total of seven ecosystem constituents. Four years of N fertilization in a semiarid shrubland completely disrupted the network of ecological interactions, with a greater proportional increase in ecosystem disruption at low N addition levels. Biotic interactions, particularly those involving microbes, shrubs, and edaphic fauna, were more prone to be lost in response to N, whereas interactions involving soil properties were more resilient. In contrast, edaphic fauna was the only group directly affected by N addition, with mites and collembolans increasing their abundance with up to 20 kg N·ha -1 ·yr -1 and then decreasing, which supports the idea of higher-trophic-level organisms being more sensitive to disturbance due to more complex links with other ecosystem constituents. Future experimental studies evaluating the impacts of N deposition, and possibly other GEC drivers, on biodiversity and biotic and abiotic interactions may be able to explain results more effectively in the context of ecological networks as a key feature of ecosystem sensitivity. © 2016 by the Ecological Society of America.

  10. Ecological interactions and the distribution, abundance, and diversity of sponges.

    Science.gov (United States)

    Wulff, Janie

    2012-01-01

    Although abiotic factors may be important first-order filters dictating which sponge species can thrive at a particular site, ecological interactions can play substantial roles influencing distribution and abundance, and thus diversity. Ecological interactions can modify the influences of abiotic factors both by further constraining distribution and abundance due to competitive or predatory interactions and by expanding habitat distribution or abundance due to beneficial interactions that ameliorate otherwise limiting circumstances. It is likely that the importance of ecological interactions has been greatly underestimated because they tend to only be revealed by experiments and time-series observations in the field. Experiments have revealed opportunistic predation to be a primary enforcer of sponge distribution boundaries that coincide with habitat boundaries in several systems. Within habitats, by contrast, dramatic effects of predators on sponge populations seem to occur primarily in cases of unusually high recruitment rates or unusually low mortality rates for the predators, which are often specialists on the sponge species affected. Competitive interactions have been demonstrated to diminish populations or exclude sponge species from a habitat in only a few cases. Cases in which competitive interactions have appeared obvious have often turned out to be neutral or even beneficial interactions when observed over time. Especially striking in this regard are sponge-sponge interactions in dense sponge-dominated communities, which may promote the continued coexistence of all participating species. Mutualistic symbioses of sponges with other animals, plants, or macroalgae have been demonstrated to increase abundance, habitat distribution, and diversity of all participants. Symbiotic microbes can enhance sponge distribution and abundance but also render their hosts more vulnerable to environmental changes. And while photosynthetic symbionts can boost growth and

  11. The Co- Occurrence of Autism and Attention Deficit Hyperactivity Disorder in children-what do we know?

    Directory of Open Access Journals (Sweden)

    Yael eLeitner

    2014-04-01

    Full Text Available Symptoms of Attention Deficit Hyperactivity Disorder (ADHD and Autistic Spectrum Disorder (ASD often co-occur. The DSM IV had specified that an ASD diagnosis is an exclusion criterion for ADHD, thereby limiting research of this common clinical co-occurrence. As neurodevelopmental disorders, both ASD and ADHD share some phenotypic similarities, but are characterized by distinct diagnostic criteria. The present review will examine the frequency and implications of this clinical co-occurrence in children, with an emphasis on the available data regarding preschool age. The review will highlight possible etiologies explaining it, and suggest future research directions necessary to enhance our understanding of both etiology and therapeutic interventions, in light of the new DSM V criteria , allowing for a dual diagnosis.

  12. Bacteria dialog with Santa Rosalia: Are aggregations of cosmopolitan bacteria mainly explained by habitat filtering or by ecological interactions?

    Science.gov (United States)

    Pascual-García, Alberto; Tamames, Javier; Bastolla, Ugo

    2014-12-04

    Since the landmark Santa Rosalia paper by Hutchinson, niche theory addresses the determinants of biodiversity in terms of both environmental and biological aspects. Disentangling the role of habitat filtering and interactions with other species is critical for understanding microbial ecology. Macroscopic biogeography explores hypothetical ecological interactions through the analysis of species associations. These methods have started to be incorporated into microbial ecology relatively recently, due to the inherent experimental difficulties and the coarse grained nature of the data. Here we investigate the influence of environmental preferences and ecological interactions in the tendency of bacterial taxa to either aggregate or segregate, using a comprehensive dataset of bacterial taxa observed in a wide variety of environments. We assess significance of taxa associations through a null model that takes into account habitat preferences and the global distribution of taxa across samples. The analysis of these associations reveals a surprisingly large number of significant aggregations between taxa, with a marked community structure and a strong propensity to aggregate for cosmopolitan taxa. Due to the coarse grained nature of our data we cannot conclusively reject the hypothesis that many of these aggregations are due to environmental preferences that the null model fails to reproduce. Nevertheless, some observations are better explained by ecological interactions than by habitat filtering. In particular, most pairs of aggregating taxa co-occur in very different environments, which makes it unlikely that these associations are due to habitat preferences, and many are formed by cosmopolitan taxa without well defined habitat preferences. Moreover, known cooperative interactions are retrieved as aggregating pairs of taxa. As observed in similar studies, we also found that phylogenetically related taxa are much more prone to aggregate than to segregate, an observation

  13. Social-ecological outcomes in recreational fisheries: the interaction of lakeshore development and stocking.

    Science.gov (United States)

    Ziegler, Jacob P; Golebie, Elizabeth J; Jones, Stuart E; Weidel, Brian C; Solomon, Christopher T

    2017-01-01

    Many ecosystems continue to experience rapid transformations due to processes like land use change and resource extraction. A systems approach to maintaining natural resources focuses on how interactions and feedbacks among components of complex social-ecological systems generate social and ecological outcomes. In recreational fisheries, residential shoreline development and fish stocking are two widespread human behaviors that influence fisheries, yet emergent social-ecological outcomes from these potentially interacting behaviors remain under explored. We applied a social-ecological systems framework using a simulation model and empirical data to determine whether lakeshore development is likely to promote stocking through its adverse effects on coarse woody habitat and thereby also on survival of juvenile and adult fish. We demonstrate that high lakeshore development is likely to generate dependency of the ecosystem on the social system, in the form of stocking. Further, lakeshore development can interact with social-ecological processes to create deficits for state-level governments, which threatens the ability to fund further ecosystem subsidies. Our results highlight the value of a social-ecological framework for maintaining ecosystem services like recreational fisheries. © 2016 by the Ecological Society of America.

  14. The Incidence of Co-occurrence of Chlamydial Cervicitis with Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Yusefi S

    2011-03-01

    Full Text Available Background and Objectives: Bacterial vaginosis is caused by an imbalance in normal vaginal bacterial flora mainly caused by the introduction of pathogenic bacteria. Failure to properly treat this condition can not only induce abortion but also increase the chance of acquiring other serious infections such as AIDS, gonorrhea and chlamydiosis. Chlamydia trchomatis is one of the causative agents of cervicitis of which 70% is totally asymptomatic. Untreated cases can lead to salpengititis, pelvic inflammatory diseases, infertility, pelvic area pains and other complications. The purpose of this study was to determine the co-occurrence of these two conditions.Methods: A total of 137 patients were examined for both Chlamydial cervicitis and for bacterial vaginosis. Gram stain was used to detect bacterial vaginosis and anti-chlamydial antibodies were titered by microimmunofluoresence (MIF assay. Results: According to the MIF results, 10 patients(7.3% had elevated anti-chlamydial IgG and 3 patients (2.2% showed high IgM titers. Gardnerella vaginalis was detected in 6 patients(4.7% as the causative agent of vaginosis. There were 3 cases of co-occurrence of chlamydial cervicitis and bacterial vaginosis (30%. Conclusion: Due to the fact that bacterial vaginosis can provide the pre-disposing conditions for cervicitis and its chronicity and the similarity of the cilinical singns of these two conditions, Infections with Chlamydia are often overlooked. It therefore seems necessary to check any patient with bacterial vaginosis for chlamydial co-infection.

  15. Social-ecological outcomes in recreational fisheries: The interaction of lakeshore development and stocking

    Science.gov (United States)

    Ziegler, Jacob P.; Golebie, Elizabeth J.; Jones, Stuart E.; Weidel, Brian C.; Solomon, Christopher T.

    2017-01-01

    Many ecosystems continue to experience rapid transformations due to processes like land use change and resource extraction. A systems approach to maintaining natural resources focuses on how interactions and feedbacks among components of complex social‐ecological systems generate social and ecological outcomes. In recreational fisheries, residential shoreline development and fish stocking are two widespread human behaviors that influence fisheries, yet emergent social‐ecological outcomes from these potentially interacting behaviors remain under explored. We applied a social‐ecological systems framework using a simulation model and empirical data to determine whether lakeshore development is likely to promote stocking through its adverse effects on coarse woody habitat and thereby also on survival of juvenile and adult fish. We demonstrate that high lakeshore development is likely to generate dependency of the ecosystem on the social system, in the form of stocking. Further, lakeshore development can interact with social‐ecological processes to create deficits for state‐level governments, which threatens the ability to fund further ecosystem subsidies. Our results highlight the value of a social‐ecological framework for maintaining ecosystem services like recreational fisheries.

  16. 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.

  17. Familial co-occurrence of congenital heart defects follows distinct patterns

    DEFF Research Database (Denmark)

    Ellesøe, Sabrina G.; Workman, Christopher T.; Bouvagnet, Patrice

    2018-01-01

    Congenital heart defects (CHD) affect almost 1% of all live born children and the number of adults with CHD is increasing. In families where CHD has occurred previously, estimates of recurrence risk, and the type of recurring malformation are important for counselling and clinical decision......-making, but the recurrence patterns in families are poorly understood. We aimed to determine recurrence patterns, by investigating the co-occurrences of CHD in 1163 families with known malformations, comprising 3080 individuals with clinically confirmed diagnosis. We calculated rates of concordance and discordance for 41...... specific types of malformations, observing a high variability in the rates of concordance and discordance. By calculating odds ratios for each of 1640 pairs of discordant lesions observed between affected family members, we were able to identify 178 pairs of malformations that co-occurred significantly...

  18. Familial co-occurrence of congenital heart defects follows distinct patterns

    DEFF Research Database (Denmark)

    Ellesøe, Sabrina G.; Workman, Christopher T.; Bouvagnet, Patrice

    2017-01-01

    Congenital heart defects (CHD) affect almost 1% of all live born children and the number of adults with CHD is increasing. In families where CHD has occurred previously, estimates of recurrence risk, and the type of recurring malformation are important for counselling and clinical decision......-making, but the recurrence patterns in families are poorly understood. We aimed to determine recurrence patterns, by investigating the co-occurrences of CHD in 1163 families with known malformations, comprising 3080 individuals with clinically confirmed diagnosis. We calculated rates of concordance and discordance for 41...... specific types of malformations, observing a high variability in the rates of concordance and discordance. By calculating odds ratios for each of 1640 pairs of discordant lesions observed between affected family members, we were able to identify 178 pairs of malformations that co-occurred significantly...

  19. Interaction networks, ecological stability, and collective antibiotic tolerance in polymicrobial infections

    Science.gov (United States)

    de Vos, Marjon G. J.; Bollenbach, Tobias

    2017-01-01

    Polymicrobial infections constitute small ecosystems that accommodate several bacterial species. Commonly, these bacteria are investigated in isolation. However, it is unknown to what extent the isolates interact and whether their interactions alter bacterial growth and ecosystem resilience in the presence and absence of antibiotics. We quantified the complete ecological interaction network for 72 bacterial isolates collected from 23 individuals diagnosed with polymicrobial urinary tract infections and found that most interactions cluster based on evolutionary relatedness. Statistical network analysis revealed that competitive and cooperative reciprocal interactions are enriched in the global network, while cooperative interactions are depleted in the individual host community networks. A population dynamics model parameterized by our measurements suggests that interactions restrict community stability, explaining the observed species diversity of these communities. We further show that the clinical isolates frequently protect each other from clinically relevant antibiotics. Together, these results highlight that ecological interactions are crucial for the growth and survival of bacteria in polymicrobial infection communities and affect their assembly and resilience. PMID:28923953

  20. Co-occurrence of Trichomonas vaginalis and bacterial vaginosis and vaginal shedding of HIV-1 RNA.

    Science.gov (United States)

    Fastring, Danielle R; Amedee, Angela; Gatski, Megan; Clark, Rebecca A; Mena, Leandro A; Levison, Judy; Schmidt, Norine; Rice, Janet; Gustat, Jeanette; Kissinger, Patricia

    2014-03-01

    Trichomonas vaginalis (TV) and bacterial vaginosis (BV) are independently associated with increased risk of vaginal shedding in HIV-positive women. Because these 2 conditions commonly co-occur, this study was undertaken to examine the association between TV/BV co-occurrence and vaginal shedding of HIV-1 RNA. HIV-positive women attending outpatient HIV clinics in 3 urban US cities underwent a clinical examination; were screened for TV, BV, Neisseria gonorrhoeae, Chlamydia trachomatis, and vulvovaginal candidiasis; and completed a behavioral survey. Women shedding HIV-1 RNA vaginally (≥50 copies/mL) were compared with women who had an undetectable (women who were TV positive and BV positive or had co-occurrence of TV/BV had higher odds of shedding vaginally when compared with women who did not have these conditions. In this sample of 373 HIV-positive women, 43.1% (n = 161) had co-occurrence of TV/BV and 33.2% (n = 124) were shedding HIV-1 RNA vaginally. The odds of shedding HIV vaginally in the presence of TV alone or BV alone and when TV/BV co-occurred were 4.07 (95% confidence interval [CI], 1.78-9.37), 5.65 (95% CI, 2.64-12.01), and 18.63 (95% CI, 6.71-51.72), respectively, when compared with women with no diagnosis of TV or BV, and after adjusting for age, antiretroviral therapy status, and plasma viral load. T. vaginalis and BV were independently and synergistically related to vaginal shedding of HIV-1 RNA. Screening and prompt treatment of these 2 conditions among HIV-positive women are important not only clinically but for HIV prevention, as well.

  1. Extracting semantic representations from word co-occurrence statistics: stop-lists, stemming, and SVD.

    Science.gov (United States)

    Bullinaria, John A; Levy, Joseph P

    2012-09-01

    In a previous article, we presented a systematic computational study of the extraction of semantic representations from the word-word co-occurrence statistics of large text corpora. The conclusion was that semantic vectors of pointwise mutual information values from very small co-occurrence windows, together with a cosine distance measure, consistently resulted in the best representations across a range of psychologically relevant semantic tasks. This article extends that study by investigating the use of three further factors--namely, the application of stop-lists, word stemming, and dimensionality reduction using singular value decomposition (SVD)--that have been used to provide improved performance elsewhere. It also introduces an additional semantic task and explores the advantages of using a much larger corpus. This leads to the discovery and analysis of improved SVD-based methods for generating semantic representations (that provide new state-of-the-art performance on a standard TOEFL task) and the identification and discussion of problems and misleading results that can arise without a full systematic study.

  2. Abundance and co-occurrence of extracellular capsules increase environmental breadth: Implications for the emergence of pathogens.

    Science.gov (United States)

    Rendueles, Olaya; Garcia-Garcerà, Marc; Néron, Bertrand; Touchon, Marie; Rocha, Eduardo P C

    2017-07-01

    Extracellular capsules constitute the outermost layer of many bacteria, are major virulence factors, and affect antimicrobial therapies. They have been used as epidemiological markers and recently became vaccination targets. Despite the efforts to biochemically serotype capsules in a few model pathogens, little is known of their taxonomic and environmental distribution. We developed, validated, and made available a computational tool, CapsuleFinder, to identify capsules in genomes. The analysis of over 2500 prokaryotic genomes, accessible in a database, revealed that ca. 50% of them-including Archaea-encode a capsule. The Wzx/Wzy-dependent capsular group was by far the most abundant. Surprisingly, a fifth of the genomes encode more than one capsule system-often from different groups-and their non-random co-occurrence suggests the existence of negative and positive epistatic interactions. To understand the role of multiple capsules, we queried more than 6700 metagenomes for the presence of species encoding capsules and showed that their distribution varied between environmental categories and, within the human microbiome, between body locations. Species encoding capsules, and especially those encoding multiple capsules, had larger environmental breadths than the other species. Accordingly, capsules were more frequent in environmental bacteria than in pathogens and, within the latter, they were more frequent among facultative pathogens. Nevertheless, capsules were frequent in clinical samples, and were usually associated with fast-growing bacteria with high infectious doses. Our results suggest that capsules increase the environmental range of bacteria and make them more resilient to environmental perturbations. Capsules might allow opportunistic pathogens to profit from empty ecological niches or environmental perturbations, such as those resulting from antibiotic therapy, to colonize the host. Capsule-associated virulence might thus be a by-product of environmental

  3. Abundance and co-occurrence of extracellular capsules increase environmental breadth: Implications for the emergence of pathogens.

    Directory of Open Access Journals (Sweden)

    Olaya Rendueles

    2017-07-01

    Full Text Available Extracellular capsules constitute the outermost layer of many bacteria, are major virulence factors, and affect antimicrobial therapies. They have been used as epidemiological markers and recently became vaccination targets. Despite the efforts to biochemically serotype capsules in a few model pathogens, little is known of their taxonomic and environmental distribution. We developed, validated, and made available a computational tool, CapsuleFinder, to identify capsules in genomes. The analysis of over 2500 prokaryotic genomes, accessible in a database, revealed that ca. 50% of them-including Archaea-encode a capsule. The Wzx/Wzy-dependent capsular group was by far the most abundant. Surprisingly, a fifth of the genomes encode more than one capsule system-often from different groups-and their non-random co-occurrence suggests the existence of negative and positive epistatic interactions. To understand the role of multiple capsules, we queried more than 6700 metagenomes for the presence of species encoding capsules and showed that their distribution varied between environmental categories and, within the human microbiome, between body locations. Species encoding capsules, and especially those encoding multiple capsules, had larger environmental breadths than the other species. Accordingly, capsules were more frequent in environmental bacteria than in pathogens and, within the latter, they were more frequent among facultative pathogens. Nevertheless, capsules were frequent in clinical samples, and were usually associated with fast-growing bacteria with high infectious doses. Our results suggest that capsules increase the environmental range of bacteria and make them more resilient to environmental perturbations. Capsules might allow opportunistic pathogens to profit from empty ecological niches or environmental perturbations, such as those resulting from antibiotic therapy, to colonize the host. Capsule-associated virulence might thus be a by

  4. Bullying and cyberbullying: overlapping and predictive value of the co-occurrence.

    Science.gov (United States)

    del Rey, Rosario; Elipe, Paz; Ortega-Ruiz, Rosario

    2012-11-01

    Several studies show certain co-occurrence of the traditional bullying and the cyberbullying. However, the results about relation and homogeneity among the roles of each of them are not unanimous. The present study intends to advance in the knowledge about the above-mentioned co-occurrence by exploring the dimensions of victimization and traditional aggression and cyber-victimization and cyber-aggression and by identifying its eventual directionality. A short-term longitudinal design was developed. The sample was formed by 274 adolescents, aging 12 to 18 years-old, belonging to 2 schools of Andalusia (South of Spain). In order to value the impact of bullying and cyberbullying the European Cyberbullying Intervention Project Questionnaire (ECIPQ) and the European Bullying Intervention Project Questionnaire (EBIPQ) were used. The results show important simultaneity among both phenomena and suggest that although in cyberbullying -cyber-victimization and cyber-aggression- may be predicted because of previous involvement of the subject in traditional bullying, on the contrary it does not happen. In addition, previous victimization is a risk factor for traditional bullying and for cyberbullying. Results are discussed in relation to the process and socio-group dynamics arising from the bullying and cyberbullying phenomena, and in terms of their prevention.

  5. Positive Association of Fibroadenomatoid Change with HER2-Negative Invasive Breast Cancer: A Co-Occurrence Study.

    Directory of Open Access Journals (Sweden)

    Yaqin Chen

    Full Text Available Risk assessment of a benign breast disease/lesion (BBD for invasive breast cancer (IBC is typically done through a longitudinal study. For an infrequently-reported BBD, the shortage of occurrence data alone is a limiting factor to conducting such a study. Here we present an approach based on co-occurrence analysis, to help address this issue. We focus on fibroadenomatoid change (FAC, an under-studied BBD, as our preliminary analysis has suggested its previously unknown significant co-occurrence with IBC.A cohort of 1667 female patients enrolled in the Clinical Breast Care Project was identified. A single experienced breast pathologist reviewed all pathology slides for each case and recorded all observed lesions, including FAC. Fibroadenoma (FA was studied for comparison since FAC had been speculated to be an immature FA. FA and Fibrocystic Changes (FCC were used for method validation since they have been comprehensively studied. Six common IBC and BBD risk/protective factors were also studied. Co-occurrence analyses were performed using logistic regression models.Common risk/protective factors were associated with FA, FCC, and IBC in ways consistent with the literature in general, and they were associated with FAC, FA, and FCC in distinct patterns. Age was associated with FAC in a bell-shape curve so that middle-aged women were more likely to have FAC. We report for the first time that FAC is positively associated with IBC with odds ratio (OR depending on BMI (OR = 6.78, 95%CI = 3.43-13.42 at BMI25 kg/m2. This association is only significant with HER2-negative IBC subtypes.We conclude that FAC is a candidate risk factor for HER2-negative IBCs, and it is a distinct disease from FA. Co-occurrence analysis can be used for initial assessment of the risk for IBC from a BBD, which is vital to the study of infrequently-reported BBDs.

  6. Positive Association of Fibroadenomatoid Change with HER2-Negative Invasive Breast Cancer: A Co-Occurrence Study

    Science.gov (United States)

    Kovatich, Albert J.; Hooke, Jeffrey A.; Liu, Jianfang; Kvecher, Leonid; Fantacone-Campbell, J. Leigh; Mitchell, Edith P.; Rui, Hallgeir; Shriver, Craig D.; Hu, Hai

    2015-01-01

    Background Risk assessment of a benign breast disease/lesion (BBD) for invasive breast cancer (IBC) is typically done through a longitudinal study. For an infrequently-reported BBD, the shortage of occurrence data alone is a limiting factor to conducting such a study. Here we present an approach based on co-occurrence analysis, to help address this issue. We focus on fibroadenomatoid change (FAC), an under-studied BBD, as our preliminary analysis has suggested its previously unknown significant co-occurrence with IBC. Methods A cohort of 1667 female patients enrolled in the Clinical Breast Care Project was identified. A single experienced breast pathologist reviewed all pathology slides for each case and recorded all observed lesions, including FAC. Fibroadenoma (FA) was studied for comparison since FAC had been speculated to be an immature FA. FA and Fibrocystic Changes (FCC) were used for method validation since they have been comprehensively studied. Six common IBC and BBD risk/protective factors were also studied. Co-occurrence analyses were performed using logistic regression models. Results Common risk/protective factors were associated with FA, FCC, and IBC in ways consistent with the literature in general, and they were associated with FAC, FA, and FCC in distinct patterns. Age was associated with FAC in a bell-shape curve so that middle-aged women were more likely to have FAC. We report for the first time that FAC is positively associated with IBC with odds ratio (OR) depending on BMI (OR = 6.78, 95%CI = 3.43-13.42 at BMI25 kg/m2). This association is only significant with HER2-negative IBC subtypes. Conclusions We conclude that FAC is a candidate risk factor for HER2-negative IBCs, and it is a distinct disease from FA. Co-occurrence analysis can be used for initial assessment of the risk for IBC from a BBD, which is vital to the study of infrequently-reported BBDs. PMID:26098961

  7. Competition for vitamin B1 (thiamin) structures numerous ecological interactions.

    Science.gov (United States)

    Kraft, Clifford E; Angert, Esther R

    2017-06-01

    Thiamin (vitamin B1) is a cofactor required for essential biochemical reactions in all living organisms, yet free thiamin is scarce in the environment. The diversity of biochemical pathways involved in the acquisition, degradation, and synthesis of thiamin indicates that organisms have evolved numerous ecological strategies for meeting this nutritional requirement. In this review we synthesize information from multiple disciplines to show how the complex biochemistry of thiamin influences ecological outcomes of interactions between organisms in environments ranging from the open ocean and the Australian outback to the gastrointestinal tract of animals. We highlight population and ecosystem responses to the availability or absence of thiamin. These include widespread mortality of fishes, birds, and mammals, as well as the thiamin-dependent regulation of ocean productivity. Overall, we portray thiamin biochemistry as the foundation for molecularly mediated ecological interactions that influence survival and abundance of a vast array of organisms.

  8. Pollutant threshold concentration determination in marine ecosystems using an ecological interaction endpoint

    International Nuclear Information System (INIS)

    Wang, Changyou; Liang, Shengkang; Guo, Wenting; Yu, Hua; Xing, Wenhui

    2015-01-01

    The threshold concentrations of pollutants are determined by extrapolating single-species effect data to community-level effects. This assumes the most sensitive endpoint of the life cycle of individuals and the species sensitivity distribution from single-species toxic effect tests, thus, ignoring the ecological interactions. The uncertainties due to this extrapolation can be partially overcome using the equilibrium point of a customized ecosystem. This method incorporates ecological interactions and integrates the effects on growth, survival, and ingestion into a single effect measure, the equilibrium point excursion in the customized ecosystem, in order to describe the toxic effects on plankton. A case study showed that the threshold concentration of copper calculated with the endpoint of the equilibrium point was 10 μg L −1 , which is significantly different from the threshold calculated with a single-species endpoint. The endpoint calculated using this method provides a more relevant measure of the ecological impact than any single individual-level endpoint. - Highlights: • Ecotoxicological effect of exposure to copper was tested on a customized ecosystem. • Equilibrium point of biomasses in the customized ecosystem was used as an endpoint. • Exposure–response relationship in a community level was built on equilibrium point. • A threshold concentration incorporating ecological interactions was derived. - The equilibrium biomass incorporating ecological interactions in a customized ecosystem was used as an endpoint to calculate the threshold concentration at a community level

  9. Molecular ecological insights into neotropical bird-tick interactions

    NARCIS (Netherlands)

    Miller, Matthew J.; Esser, Helen J.; Loaiza, Jose R.; Herre, Edward Allen; Aguilar, Celestino; Quintero, Diomedes; Alvarez, Eric; Bermingham, Eldredge

    2016-01-01

    In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In

  10. The co-occurrence of multiple sclerosis and type 1 diabetes: shared aetiologic features and clinical implication for MS aetiology.

    Science.gov (United States)

    Tettey, Prudence; Simpson, Steve; Taylor, Bruce V; van der Mei, Ingrid A F

    2015-01-15

    We reviewed the evidence for the co-occurrence of type 1 diabetes mellitus (T1D) and multiple sclerosis (MS), and assessed the clinical significance of this association and the shared aetiological features of the two diseases. T1D and MS contribute considerably to the burden of autoimmune diseases in young adults. The co-occurrence of MS and T1D has been reported by a number of studies, suggesting that the two conditions share one or more aetiological components. Both conditions have been associated with distinct human leukocyte antigen (HLA) haplotypes but share a number of similarities in clinical, epidemiological and immunological features, leading to suggestions of possible common mechanisms of development. While underlying genetic factors may be important for the co-occurrence of both conditions, some evidence suggests that environmental factors such as vitamin D deficiency may also modulate an individual's risk for the development of both conditions. Evidence on whether the co-occurrence of the two autoimmune conditions will affect the disease course and severity of MS is merely absent. Further studies need to be conducted to ascertain whether the neuropathology associated with T1D might influence the disease course and contribute to the severity of MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Interactions between plants and primates shape community diversity in a rainforest in Madagascar.

    Science.gov (United States)

    Herrera, James P

    2016-07-01

    Models of ecological community assembly predict how communities of interacting organisms may be shaped by abiotic and biotic factors. Competition and environmental filtering are the predominant factors hypothesized to explain community assembly. This study tested the effects of habitat, phylogenetic and phenotypic trait predictors on species co-occurrence patterns and abundances, with the endemic primates of Madagascar as an empirical system. The abundance of 11 primate species was estimated along gradients of elevation, food resource abundance and anthropogenic habitat disturbance at local scales in south-east Madagascar. Community composition was compared to null models to test for phylogenetic and functional structure, and the effects of phylogenetic relatedness of co-occurring species, their trait similarity and environmental variables on species' abundances were tested using mixed models and quantile regressions. Resource abundance was the strongest predictor of community structure. Where food tree abundance was high, closely related species with similar traits dominated communities. High-elevation communities with lower food tree abundance consisted of species that were distantly related and had divergent traits. Closely related species had dissimilar abundances where they co-occurred, partially driven by trait dissimilarity, indicating character displacement. By integrating local-scale variation in primate community composition, evolutionary relatedness and functional diversity, this study found strong evidence that community assembly in this system can be explained by competition and character displacement along ecological gradients. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  12. The roles of amensalistic and commensalistic interactions in large ecological network stability.

    Science.gov (United States)

    Mougi, Akihiko

    2016-07-13

    Ecological communities comprise diverse species and their interactions. Notably, ecological and evolutionary studies have revealed that reciprocal interactions such as predator-prey, competition, and mutualism, are key drivers of community dynamics. However, there is an argument that many species interactions are asymmetric, where one species unilaterally affects another species (amensalism or commensalism). This raises the unanswered question of what is the role of unilateral interactions in community dynamics. Here I use a theoretical approach to demonstrate that unilateral interactions greatly enhance community stability. The results suggested that amensalism and commensalism were more stabilizing than symmetrical interactions, such as competition and mutualism, but they were less stabilizing than an asymmetric antagonistic interaction. A mix of unilateral interactions increased stability. Furthermore, in communities with all interaction types, unilateral interactions tended to increase stability. This study suggests that unilateral interactions play a major role in maintaining communities, underlining the need to further investigate their roles in ecosystem dynamics.

  13. Response of Fagus sylvatica and Picea abies to the interactive effect of neighbor identity and enhanced CO2 levels

    Czech Academy of Sciences Publication Activity Database

    Rolo, V.; Andivia, E.; Pokorný, Radek

    2015-01-01

    Roč. 29, č. 5 (2015), s. 1459-1469 ISSN 0931-1890 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : mixed-forest * climate change * root morphology * growth * non-structural carbohydrates * CO2 fumigation * plant-to-plant interactions Subject RIV: EH - Ecology, Behaviour Impact factor: 1.706, year: 2015

  14. Metacognitive interpersonal therapy for co-occurrent avoidant personality disorder and substance abuse.

    Science.gov (United States)

    Dimaggio, Giancarlo; D'Urzo, Maddalena; Pasinetti, Manuela; Salvatore, Giampaolo; Lysaker, Paul H; Catania, Dario; Popolo, Raffaele

    2015-02-01

    Many patients with substance abuse problems present with co-occurrent cluster C personality disorders. Focusing on both disorders disrupts the maintenance mechanisms and the vicious cycle between the 2 conditions; however, treatment teams often neglect this issue. In this work, we describe the features of metacognitive interpersonal therapy as applied to a man with avoidant and depressive personality disorders and heroin, cocaine, and alcohol abuse. Psychotherapy proceeded through the following steps: (a) conducting drug therapy to deal with symptoms of abstinence from heroin; (b) forming a therapeutic bond to overcome the patient's severe emotional withdrawal; (c) fostering basic metacognitive capacities such as awareness of emotions and their triggers; (d) sharing formulations of maladaptive interpersonal schemas and descriptions of the associated states of mind; (e) conveying an understanding of the link between interpersonal events (recent ones and traumatic memories) and substance abuse; (f) facilitating the acquisition of critical distance from maladaptive schemas; and (g) promoting the use of adaptive coping skills instead of resorting to substance abuse. Implications for generalizing these procedures to the treatment of other patients with co-occurrent personality disorders and substance abuse are described. © 2014 Wiley Periodicals, Inc.

  15. Patterns and correlates of co-occurrence among multiple types of child maltreatment

    Science.gov (United States)

    Kim, Kihyun; Mennen, Ferol E.; Trickett, Penelope K.

    2017-01-01

    This study examined the patterns and correlates of the types of maltreatment experienced by adolescents aged 9–12, participating in an ongoing longitudinal study on the impact of neglect on children’s development. Using case record abstraction, the study compared the child protection classification and findings from the case record abstraction with regard to the rates of four types of maltreatment (i.e. physical, sexual, emotional abuse and neglect) as well as co-occurrence across multiple types of maltreatment. Next, the study examined the frequently observed patterns of child maltreatment. Finally, the study investigated whether aspects of caretaker functioning and the detailed incident characteristics in the cases of neglect differed by the number of different types of maltreatment the children experienced. Results showed significant discrepancies between the Child Protective Service classification and case record abstraction. Child Protective Service classification considerably underestimated the rate of co-occurrence across multiple types of maltreatment. Neglect accompanied by physical and emotional abuse was the most common form. Some of the caretaker functioning variables distinguished the number of types of maltreatment. Based on the findings, future-research directions and practice implication were discussed. PMID:29225485

  16. Drunkorexia: Understanding the Co-Occurrence of Alcohol Consumption and Eating/Exercise Weight Management Behaviors

    Science.gov (United States)

    Barry, Adam E.; Piazza-Gardner, Anna K.

    2012-01-01

    Objective: Examine the co-occurrence of alcohol consumption, physical activity, and disordered eating behaviors via a drunkorexia perspective. Participants: Nationally representative sample (n = 22,488) of college students completing the Fall 2008 National College Health Assessment. Methods: Hierarchical logistic regression was employed to…

  17. Co-occurrence of intraoral hemangioma and port wine stain: A rare case

    Directory of Open Access Journals (Sweden)

    Prasanna Kumar Rao

    2012-01-01

    Full Text Available Hemangiomas are neoplastic proliferations of endothelial cells, characterized by a period of growth after birth, and eventual spontaneous involution. The course can be uneventful with spontaneous resolution; or it may be marked by complications such as infection, bleeding, ulceration, visual defects and feeding difficulties. Apart from these, rare life-threatening complications such as congestive heart failure and consumption coagulopathy may also be seen. Although hemangiomas commonly occur in the head and neck region, intraoral occurrence is relatively rare. A port wine stain is defined as a macular telangiectatic patch which is present at birth and remains throughout life. They may be localized or extensive, affecting a whole limb. This article reports a rare case of co-occurrence of port wine stain with intraoral hemangioma.

  18. Affect and Health Behavior Co-Occurrence: The Emerging Roles of Transdiagnostic Factors and Sociocultural Factors.

    Science.gov (United States)

    Zvolensky, Michael J; Leventhal, Adam M

    2016-01-01

    The majority of scientific work addressing relations among affective states and health correlates has focused primarily on their co-occurrence and a limited range of health conditions. We have developed a Special Issue to highlight recent advances in this emerging field of work that addresses the nature and interplay between affective states and disorders, in terms of their impact and consequences from health status and behavior. This Special Issue is organized into three parts classified as (a) co-occurrence and interplay between (b) transdiagnostic factors and (c) sociocultural factors. It is hoped that this issue will (a) alert readers to the significance of this work at different levels of analysis, (b) illustrate the many domains currently being explored via innovative approaches, and (c) identify fecund areas for future systematic study. © The Author(s) 2016.

  19. In vitro co-cultures of human gut bacterial species as predicted from co-occurrence network analysis

    DEFF Research Database (Denmark)

    Das, Promi; Ji, Boyang; Kovatcheva-Datchary, Petia

    2018-01-01

    Network analysis of large metagenomic datasets generated by current sequencing technologies can reveal significant co-occurrence patterns between microbial species of a biological community. These patterns can be analyzed in terms of pairwise combinations between all species comprising a community...... thetaiotaomicron, as well as Faecalibacterium prausnitzii and Roseburia inulinivorans as model organisms for our study. We then delineate the outcome of the co-cultures when equal distributions of resources were provided. The growth behavior of the co-culture was found to be dependent on the types of microbial...... species present, their specific metabolic activities, and resulting changes in the culture environment. Through this reductionist approach and using novel in vitro combinations of microbial species under anaerobic conditions, the results of this work will aid in the understanding and design of synthetic...

  20. A novel co-occurrence-based approach to predict pure associative and semantic priming.

    Science.gov (United States)

    Roelke, Andre; Franke, Nicole; Biemann, Chris; Radach, Ralph; Jacobs, Arthur M; Hofmann, Markus J

    2018-03-15

    The theoretical "difficulty in separating association strength from [semantic] feature overlap" has resulted in inconsistent findings of either the presence or absence of "pure" associative priming in recent literature (Hutchison, 2003, Psychonomic Bulletin & Review, 10(4), p. 787). The present study used co-occurrence statistics of words in sentences to provide a full factorial manipulation of direct association (strong/no) and the number of common associates (many/no) of the prime and target words. These common associates were proposed to serve as semantic features for a recent interactive activation model of semantic processing (i.e., the associative read-out model; Hofmann & Jacobs, 2014). With stimulus onset asynchrony (SOA) as an additional factor, our findings indicate that associative and semantic priming are indeed dissociable. Moreover, the effect of direct association was strongest at a long SOA (1,000 ms), while many common associates facilitated lexical decisions primarily at a short SOA (200 ms). This response pattern is consistent with previous performance-based accounts and suggests that associative and semantic priming can be evoked by computationally determined direct and common associations.

  1. Rare co-occurrence of osteogenesis imperfecta type I and autosomal dominant polycystic kidney disease.

    Science.gov (United States)

    Hoefele, Julia; Mayer, Karin; Marschall, Christoph; Alberer, Martin; Klein, Hanns-Georg; Kirschstein, Martin

    2016-11-01

    There are several clinical reports about the co-occurrence of autosomal dominant polycystic kidney disease (ADPKD) and connective tissue disorders. A simultaneous occurrence of osteogenesis imperfecta (OI) type I and ADPKD has not been observed so far. This report presents the first patient with OI type I and ADPKD. Mutational analysis of PKD1 and COL1A1 in the index patient revealed a heterozygous mutation in each of the two genes. Mutational analysis of the parents indicated the mother as a carrier of the PKD1 mutation and the father as a carrier of the COL1A1 mutation. The simultaneous occurrence of both disorders has an estimated frequency of 3.5:100 000 000. In singular cases, ADPKD can occur in combination with other rare disorders, e.g. connective tissue disorders.

  2. The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence.

    Directory of Open Access Journals (Sweden)

    Andrew Ladle

    Full Text Available Species' distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use. We documented (a occurrence of grizzly bears and black bears relative to habitat variables (b occurrence and intensity of use relative to competing bear species and motorised and non-motorised recreational activity, and (c temporal overlap in activity patterns among the two bear species and recreationists. Grizzly bears were spatially separated from black bears, selecting higher elevations and locations farther from roads. Both species co-occurred with motorised and non-motorised recreation, however, grizzly bears reduced their intensity of use of sites with motorised recreation present. Black bears showed higher temporal activity overlap with recreational activity than grizzly bears, however differences in bear daily activity patterns between sites with and without motorised and non-motorised recreation were not significant. Reduced intensity of use by grizzly bears of sites where motorised recreation was present is a concern given off-road recreation is becoming increasingly popular in North America, and can negatively influence grizzly bear recovery by reducing foraging opportunities near or on trails. Camera traps and multi-species occurrence models offer non-invasive methods for identifying how habitat use by animals changes relative to sympatric species, including humans. These conclusions emphasise the need for integrated land-use planning, access management, and grizzly bear conservation efforts to consider the implications of continued access for

  3. The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence.

    Science.gov (United States)

    Ladle, Andrew; Steenweg, Robin; Shepherd, Brenda; Boyce, Mark S

    2018-01-01

    Species' distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use. We documented (a) occurrence of grizzly bears and black bears relative to habitat variables (b) occurrence and intensity of use relative to competing bear species and motorised and non-motorised recreational activity, and (c) temporal overlap in activity patterns among the two bear species and recreationists. Grizzly bears were spatially separated from black bears, selecting higher elevations and locations farther from roads. Both species co-occurred with motorised and non-motorised recreation, however, grizzly bears reduced their intensity of use of sites with motorised recreation present. Black bears showed higher temporal activity overlap with recreational activity than grizzly bears, however differences in bear daily activity patterns between sites with and without motorised and non-motorised recreation were not significant. Reduced intensity of use by grizzly bears of sites where motorised recreation was present is a concern given off-road recreation is becoming increasingly popular in North America, and can negatively influence grizzly bear recovery by reducing foraging opportunities near or on trails. Camera traps and multi-species occurrence models offer non-invasive methods for identifying how habitat use by animals changes relative to sympatric species, including humans. These conclusions emphasise the need for integrated land-use planning, access management, and grizzly bear conservation efforts to consider the implications of continued access for motorised

  4. Natural co-occurrence of fungi and mycotoxins in poultry feeds from Entre Ríos, Argentina.

    Science.gov (United States)

    Monge, M P; Dalcero, A M; Magnoli, C E; Chiacchiera, S M

    2013-01-01

    A total of 120 pelleted poultry feed samples from Entre Ríos Province, Argentina, were evaluated. The aims were to investigate (1) the presence of relevant toxigenic fungi, as well as to determine the ability to produce aflatoxins (AFs) by Aspergillus section Flavi isolated strains; and (2) the natural co-occurrence of AFs, fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 and T-2 toxin by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Total fungal counts were below the established value (1 × 10⁴ CFU g⁻¹). Aspergillus flavus and A. parasiticus were the only aflatoxigenic species isolated. Co-occurrence of fumonisin B₁ (FB₁), HT-2 and T-2 toxin was detected in 100% of the feeds, with mean levels from 4502 to 5813; 6.7 to 21.6 and 19.6 to 30.3 µg kg⁻¹, respectively. A large number of starter samples were co-contaminated with aflatoxin B₁ (AFB₁), FB₁, HT-2 and T-2 toxins. Gliotoxin and DAS were not found in this survey.

  5. Morphological similarity and ecological overlap in two rotifer species.

    Science.gov (United States)

    Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José

    2013-01-01

    Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on

  6. Morphological similarity and ecological overlap in two rotifer species.

    Directory of Open Access Journals (Sweden)

    Carmen Gabaldón

    Full Text Available Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention, these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1 functional response, expressed by clearance rates; (2 tolerance to starvation, measured by growth and reproduction; and (3 vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not

  7. Overlapping and co-occurrence pattern of Anastrepha species (Diptera, Tephritidae in anthropic areas

    Directory of Open Access Journals (Sweden)

    Tayron Sousa Amaral

    2017-12-01

    Full Text Available This study was carried out in two anthropic areas (Fazenda Areão and Monte Olimpo on the “Luiz de Queiroz” campus, University of São Paulo, Piracicaba, SP. We analyzed data from 52 collections of 14 McPhail traps distributed in both areas. A total of 1,583 females belonging to 14 species were collected, including Anastrepha amita Zucchi, A. barbiellinii Lima, A. bistrigata Bezzi, A. daciformis Bezzi, A. distincta Greene, A. fraterculus (Wiedemann, A. grandis (Macquart, A. manihoti Lima, A. montei Lima, A. obliqua (Macquart, A. pickeli Lima, A. pseudoparallela (Loew, A. serpentina (Wiedemann and A. sororcula Zucchi. A greater number of specimens (1,041 were collected at the Fazenda Areão compared to Monte Olimpo (542. The mean niche overlap was greater than expected at random for both areas; therefore, the ecological niches of the species largely overlap. The pattern of co-occurrence indicates that segregation was not random between two pairs of species: A. pseudoparallela × A. obliqua (Fazenda Areão and A. fraterculus × A. pseudoparallela (Monte Olimpo. This segregation suggests that there may be competition for resources in each niche. The analysis also revealed three aggregated species pairs: A. bistrigata × A. montei, A. fraterculus × A. barbiellinii (Fazenda Areão, and A. fraterculus × A. bistrigata (Monte Olimpo, indicating that each pair occurs concomitantly without interfering with the permanence of the populations in these areas.

  8. Credit of ecological interactions: A new conceptual framework to support conservation in a defaunated world.

    Science.gov (United States)

    Genes, Luísa; Cid, Bruno; Fernandez, Fernando A S; Pires, Alexandra S

    2017-03-01

    As defaunation spreads through the world, there is an urgent need for restoring ecological interactions, thus assuring ecosystem processes. Here, we define the new concept of credit of ecological interactions , as the number of interactions that can be restored in a focal area by species colonization or reintroduction. We also define rewiring time , as the time span until all the links that build the credit of ecological interactions of a focal area have become functional again. We expect that the credit will be gradually cashed following refaunation in rates that are proportional to (1) the abundance of the reintroduced species (that is expected to increase in time since release), (2) the abundance of the local species that interact with them, and (3) the traits of reintroduced species. We illustrated this approach using a theoretical model and an empirical case study where the credit of ecological interactions was estimated. This new conceptual framework is useful for setting reintroduction priorities and for evaluating the success of conservation initiatives that aim to restore ecosystem services.

  9. Mycotoxigenic fungi and natural co-occurrence of mycotoxins in rainbow trout (Oncorhynchus mykiss) feeds.

    Science.gov (United States)

    Greco, Mariana; Pardo, Alejandro; Pose, Graciela

    2015-11-05

    Samples of rainbow trout feed were analyzed with the aim to determine the mycobiota composition and the co-occurrence of mycotoxins. A total of 28 samples of finished rainbow trout feed from hatcheries in the provinces of Río Negro and Neuquén, Argentina, were studied. Fungal counts were obtained on three culture media in the ranges of Aspergillus (Fr 3.6%). The most prevalent mycotoxigenic species were E. repens (Fr 21.4%) and E. rubrum (Fr 14.3%). All samples were contaminated with mycotoxins: 64% samples were contaminated with T-2 toxin (median 70.08 ppb), 50% samples with zearalenone (median 87.97 ppb) and aflatoxins (median 2.82 ppb), 25% with ochratoxin A (median 5.26 ppb) and 3.57% samples with deoxynivalenol (median 230 ppb). Eight samples had a fumonisins contamination level below the limit of detection. Co-occurrence of six mycotoxins was determined in 7% of the samples.

  10. Plant-aphid interactions: molecular and ecological perspectives.

    Science.gov (United States)

    Goggin, Fiona L

    2007-08-01

    Many aphids are major agricultural pests because of their unparalleled reproductive capacity and their ability to manipulate host plant physiology. Aphid population growth and its impact on plant fitness are strongly influenced by interactions with other organisms, including plant pathogens, endophytes, aphid endosymbionts, predators, parasitoids, ants, and other herbivores. Numerous molecular and genomic resources have recently been developed to identify sources of aphid resistance in plants, as well as potentially novel targets for control in aphids. Moreover, the same model systems that are used to explore direct molecular interactions between plants and aphids can be utilized to study the ecological context in which they occur.

  11. Interaction type influences ecological network structure more than local abiotic conditions: evidence from endophytic and endolichenic fungi at a continental scale.

    Science.gov (United States)

    Chagnon, Pierre-Luc; U'Ren, Jana M; Miadlikowska, Jolanta; Lutzoni, François; Arnold, A Elizabeth

    2016-01-01

    Understanding the factors that shape community assembly remains one of the most enduring and important questions in modern ecology. Network theory can reveal rules of community assembly within and across study systems and suggest novel hypotheses regarding the formation and stability of communities. However, such studies generally face the challenge of disentangling the relative influence of factors such as interaction type and environmental conditions on shaping communities and associated networks. Endophytic and endolichenic symbioses, characterized by microbial species that occur within healthy plants and lichen thalli, represent some of the most ubiquitous interactions in nature. Fungi that engage in these symbioses are hyperdiverse, often horizontally transmitted, and functionally beneficial in many cases, and they represent the diversification of multiple phylogenetic groups. We evaluated six measures of ecological network structure for >4100 isolates of endophytic and endolichenic fungi collected systematically from five sites across North America. Our comparison of these co-occurring interactions in biomes ranging from tundra to subtropical forest showed that the type of interactions (i.e., endophytic vs. endolichenic) had a much more pronounced influence on network structure than did environmental conditions. In particular, endophytic networks were less nested, less connected, and more modular than endolichenic networks in all sites. The consistency of the network structure within each interaction type, independent of site, is encouraging for current efforts devoted to gathering metadata on ecological network structure at a global scale. We discuss several mechanisms potentially responsible for such patterns and draw attention to knowledge gaps in our understanding of networks for diverse interaction types.

  12. The evolutionary ecology of cytonuclear interactions in angiosperms.

    Science.gov (United States)

    Caruso, Christina M; Case, Andrea L; Bailey, Maia F

    2012-11-01

    Interactions between cytoplasmic and nuclear genomes have significant evolutionary consequences. In angiosperms, the most common cytonuclear interaction is between mitochondrial genes that disrupt pollen production (cytoplasmic male sterility, CMS) and nuclear genes that restore it (nuclear male fertility restorers, Rf). The outcome of CMS/Rf interactions can depend on whether Rf alleles have negative pleiotropic effects on fitness. Although these fitness costs are often considered to be independent of the ecological context, we argue that the effects of Rf alleles on fitness should be context dependent. Thus, measuring the cost of restoration across a range of environments could help explain geographic and phylogenetic variation in the distribution of Rf alleles and the outcome of CMS/Rf interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Substance Use, Aggression Perpetration, and Victimization: Temporal Co-Occurrence in College Males and Females

    Science.gov (United States)

    Margolin, Gayla; Ramos, Michelle C.; Baucom, Brian R.; Bennett, Diana C.; Guran, Elyse L.

    2013-01-01

    Many studies have documented associations of substance use with aggression perpetration and aggression victimization; however, little is known about the co-occurrence of these problem behaviors within the same day in college students. The present study investigated whether substance use and aggression increase the likelihood of each other and…

  14. Alleviating Search Uncertainty through Concept Associations: Automatic Indexing, Co-Occurrence Analysis, and Parallel Computing.

    Science.gov (United States)

    Chen, Hsinchun; Martinez, Joanne; Kirchhoff, Amy; Ng, Tobun D.; Schatz, Bruce R.

    1998-01-01

    Grounded on object filtering, automatic indexing, and co-occurrence analysis, an experiment was performed using a parallel supercomputer to analyze over 400,000 abstracts in an INSPEC computer engineering collection. A user evaluation revealed that system-generated thesauri were better than the human-generated INSPEC subject thesaurus in concept…

  15. Taxon abundance, diversity, co-occurrence and network analysis of the ruminal microbiota in response to dietary changes in dairy cows.

    Directory of Open Access Journals (Sweden)

    Ilma Tapio

    Full Text Available The ruminal microbiome, comprising large numbers of bacteria, ciliate protozoa, archaea and fungi, responds to diet and dietary additives in a complex way. The aim of this study was to investigate the benefits of increasing the depth of the community analysis in describing and explaining responses to dietary changes. Quantitative PCR, ssu rRNA amplicon based taxa composition, diversity and co-occurrence network analyses were applied to ruminal digesta samples obtained from four multiparous Nordic Red dairy cows fitted with rumen cannulae. The cows received diets with forage:concentrate ratio either 35:65 (diet H or 65:35 (L, supplemented or not with sunflower oil (SO (0 or 50 g/kg diet dry matter, supplied in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments and four 35-day periods. Digesta samples were collected on days 22 and 24 and combined. QPCR provided a broad picture in which a large fall in the abundance of fungi was seen with SO in the H but not the L diet. Amplicon sequencing showed higher community diversity indices in L as compared to H diets and revealed diet specific taxa abundance changes, highlighting large differences in protozoal and fungal composition. Methanobrevibacter ruminantium and Mbb. gottschalkii dominated archaeal communities, and their abundance correlated negatively with each other. Co-occurrence network analysis provided evidence that no microbial domain played a more central role in network formation, that some minor-abundance taxa were at nodes of highest centrality, and that microbial interactions were diet specific. Networks added new dimensions to our understanding of the diet effect on rumen microbial community interactions.

  16. Spatial Heterogeneity of Habitat Suitability for Rift Valley Fever Occurrence in Tanzania: An Ecological Niche Modelling Approach

    Science.gov (United States)

    Sindato, Calvin; Stevens, Kim B.; Karimuribo, Esron D.; Mboera, Leonard E. G.; Paweska, Janusz T.; Pfeiffer, Dirk U.

    2016-01-01

    Background Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Materials and Methods Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Principal Findings Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). Conclusion/Significance The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with

  17. Plant Insecticidal Toxins in Ecological Networks

    Directory of Open Access Journals (Sweden)

    Sébastien Ibanez

    2012-04-01

    Full Text Available Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects’ vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology.

  18. Plant insecticidal toxins in ecological networks.

    Science.gov (United States)

    Ibanez, Sébastien; Gallet, Christiane; Després, Laurence

    2012-04-01

    Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects' vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology.

  19. Genetic Allee effects and their interaction with ecological Allee effects.

    Science.gov (United States)

    Wittmann, Meike J; Stuis, Hanna; Metzler, Dirk

    2018-01-01

    It is now widely accepted that genetic processes such as inbreeding depression and loss of genetic variation can increase the extinction risk of small populations. However, it is generally unclear whether extinction risk from genetic causes gradually increases with decreasing population size or whether there is a sharp transition around a specific threshold population size. In the ecological literature, such threshold phenomena are called 'strong Allee effects' and they can arise for example from mate limitation in small populations. In this study, we aim to (i) develop a meaningful notion of a 'strong genetic Allee effect', (ii) explore whether and under what conditions such an effect can arise from inbreeding depression due to recessive deleterious mutations, and (iii) quantify the interaction of potential genetic Allee effects with the well-known mate-finding Allee effect. We define a strong genetic Allee effect as a genetic process that causes a population's survival probability to be a sigmoid function of its initial size. The inflection point of this function defines the critical population size. To characterize survival-probability curves, we develop and analyse simple stochastic models for the ecology and genetics of small populations. Our results indicate that inbreeding depression can indeed cause a strong genetic Allee effect, but only if individuals carry sufficiently many deleterious mutations (lethal equivalents). Populations suffering from a genetic Allee effect often first grow, then decline as inbreeding depression sets in and then potentially recover as deleterious mutations are purged. Critical population sizes of ecological and genetic Allee effects appear to be often additive, but even superadditive interactions are possible. Many published estimates for the number of lethal equivalents in birds and mammals fall in the parameter range where strong genetic Allee effects are expected. Unfortunately, extinction risk due to genetic Allee effects

  20. Current Situation of Mycotoxin Contamination and Co-occurrence in Animal Feed—Focus on Europe

    Directory of Open Access Journals (Sweden)

    Isabelle P. Oswald

    2012-10-01

    Full Text Available Mycotoxins are secondary metabolites produced by fungi especially those belonging to the genus Aspergillus, Penicillum and Fusarium. Mycotoxin contamination can occur in all agricultural commodities in the field and/or during storage, if conditions are favourable to fungal growth. Regarding animal feed, five mycotoxins (aflatoxins, deoxynivalenol, zearalenone, fumonisins and ochratoxin A are covered by EU legislation (regulation or recommendation. Transgressions of these limits are rarely observed in official monitoring programs. However, low level contamination by Fusarium toxins is very common (e.g., deoxynivalenol (DON is typically found in more than 50% of the samples and co-contamination is frequently observed. Multi-mycotoxin studies reported 75%–100% of the samples to contain more than one mycotoxin which could impact animal health at already low doses. Co-occurrence of mycotoxins is likely to arise for at least three different reasons (i most fungi are able to simultaneously produce a number of mycotoxins, (ii commodities can be contaminated by several fungi, and (iii completed feed is made from various commodities. In the present paper, we reviewed the data published since 2004 concerning the contamination of animal feed with single or combinations of mycotoxins  and highlighted the occurrence of these co-contaminations.

  1. Plant–insect interactions: the role of ecological stoichiometry

    Directory of Open Access Journals (Sweden)

    Michał Filipiak

    2017-03-01

    Full Text Available The energy budget of organisms is a primary factor used to generate hypotheses in ecosystem ecology and evolutionary theory. Therefore, previous studies have focused on the energy costs and benefits of adaptations, the efficiency of energy acquisition and investment, and energy budget limitations. The maintenance of stoichiometric balance is equally important because inconsistency between the chemical composition of the consumer’s tissues and that of its food sources strongly affects the major life-history traits of the consumer and may influence the consumer’s fitness and shape plant–herbivore interactions. In this short review, the framework of ecological stoichiometry is introduced, focusing on plant–insect interactions in terrestrial ecosystems. The use of the trophic stoichiometric ratio (TSR index is presented as a useful tool for indicating the chemical elements that are scarce in food and have the potential to limit the growth and development of herbivores, thereby influencing plant – herbivorous insect interactions. As an example, the elemental composition and stoichiometry of a pollen consumer (mason bee Osmia bicornis and its preferred pollen are compared. The growth and development of O. bicornis may be colimited by the scarcity of K, Na, and N in pollen, whereas the development of the cocoon might be colimited by the scarcity of P, Mg, K, Na, Zn, Ca, and N. A literature review of the elemental composition of pollen shows high taxonomical variability in the concentrations of bee-limiting elements. The optimized collection of pollen species based on the elemental composition may represent a strategy used by bees to overcome stoichiometric mismatches, influencing their interactions with plants. It is concluded that the dependence of life-history traits on food stoichiometry should be considered when discussing life history evolution and plant–herbivore interactions. The TSR index may serve as a convenient and powerful tool

  2. The co-occurrence of autistic traits and borderline personality disorder traits is associated to increased suicidal ideation in nonclinical young adults.

    Science.gov (United States)

    Chabrol, Henri; Raynal, Patrick

    2018-04-01

    The co-occurrence of Autism Spectrum Disorder (ASD) and Borderline Personality Disorder (BPD) is not rare and has been linked to increased suicidality. Despite this significant comorbidity between ASD and BPD, no study had examined the co-occurrence of autistic traits and borderline personality disorder traits in the general population. The aim of the present study was to examine the co-occurrence of autistic and borderline traits in a non-clinical sample of young adults and its influence on the levels of suicidal ideation and depressive symptomatology. Participants were 474 college students who completed self-report questionnaires. Data were analysed using correlation and cluster analyses. Borderline personality traits and autistic traits were weakly correlated. However, cluster analysis yielded four groups: a low traits group, a borderline traits group, an autistic traits group, and a group characterized by high levels of both traits. Cluster analysis revealed that autistic and borderline traits can co-occur in a significant proportion of young adults. The high autistic and borderline traits group constituted 17% of the total sample and had higher level of suicidal ideation than the borderline traits group, despite similar levels of depressive symptoms. This result suggests that the higher suicidality observed in patients with comorbid ASD and BPD may extent to non-clinical individuals with high levels of co-occurrent autistic and borderline traits. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Antibiotic cross-resistance in the lab and resistance co-occurrence in the clinic: Discrepancies and implications in E.coli.

    Science.gov (United States)

    Obolski, Uri; Dellus-Gur, Eynat; Stein, Gideon Y; Hadany, Lilach

    2016-06-01

    Antibiotic resistance is an important public health issue, and vast resources are invested in researching new ways to fight it. Recent experimental works have shown that resistance to some antibiotics can result in increased susceptibility to others, namely induce cross-sensitivity. This phenomenon could be utilized to increase efficiency of antibiotic treatment strategies that minimize resistance. However, as conditions in experimental settings and in the clinic may differ substantially, the implications of cross-sensitivity for clinical settings are not guaranteed and should be examined. In this work we analyzed data of Escherichia coli isolates from patients' blood, sampled in Rabin Medical Center, Israel, to examine co-occurrence of resistance to antibiotics in the clinic. We compared the co-occurrence patterns with cross-sensitivity patterns observed in the lab. Our data showed only positively associated occurrence of resistance, even with antibiotics that were shown to induce cross-sensitivity in laboratory conditions. We used a mathematical model to examine the potential effects of cross-sensitivity versus co-occurrence on the spread of drug resistance. We conclude that resistance frequencies in the clinic can have a substantial effect on the success of treatment strategies, and should be considered alongside experimental evidence of cross-sensitivity. Copyright © 2016. Published by Elsevier B.V.

  4. Improving pairwise comparison of protein sequences with domain co-occurrence

    Science.gov (United States)

    Gascuel, Olivier

    2018-01-01

    Comparing and aligning protein sequences is an essential task in bioinformatics. More specifically, local alignment tools like BLAST are widely used for identifying conserved protein sub-sequences, which likely correspond to protein domains or functional motifs. However, to limit the number of false positives, these tools are used with stringent sequence-similarity thresholds and hence can miss several hits, especially for species that are phylogenetically distant from reference organisms. A solution to this problem is then to integrate additional contextual information to the procedure. Here, we propose to use domain co-occurrence to increase the sensitivity of pairwise sequence comparisons. Domain co-occurrence is a strong feature of proteins, since most protein domains tend to appear with a limited number of other domains on the same protein. We propose a method to take this information into account in a typical BLAST analysis and to construct new domain families on the basis of these results. We used Plasmodium falciparum as a case study to evaluate our method. The experimental findings showed an increase of 14% of the number of significant BLAST hits and an increase of 25% of the proteome area that can be covered with a domain. Our method identified 2240 new domains for which, in most cases, no model of the Pfam database could be linked. Moreover, our study of the quality of the new domains in terms of alignment and physicochemical properties show that they are close to that of standard Pfam domains. Source code of the proposed approach and supplementary data are available at: https://gite.lirmm.fr/menichelli/pairwise-comparison-with-cooccurrence PMID:29293498

  5. Co-occurrence of risk behaviors among Spanish adolescents

    Directory of Open Access Journals (Sweden)

    Meneses, Carmen

    2012-09-01

    Full Text Available This work examines the co-occurrence of risk behaviors among Spanish adolescents. The analyzed behaviors were sexual activity, the use of alcohol and other drugs, violent conduct and behaviors related to driving mopeds or scooters. The sample consisted of 4,091 adolescents between the ages of 13 to 18, all of them enrolled in one of the four compulsory years of secondary education, the approximate equivalents of the 7th to 10th grades in the US educational system. Cluster analysis indicates that there are four risk profiles, one of which is the profile with the greatest risk and the highest co-occurrence of risk behaviors. This group represents 13% of the sample and is noteworthy for using illegal drugs, driving under the influence of drugs and other activities carried out under the influence of alcohol. Differences have been found among the various profiles according to sociodemographic characteristics such as sex, grade, perception of the family’s economic situation and ethnicity. The findings are discussed and some suggestions are given for prevention intervention.

    Este trabajo examina la concurrencia de comportamientos de riesgo en adolescentes españoles. Los comportamientos analizados fueron la actividad sexual, el consumo de alcohol y otras drogas, conductas violentas y comportamientos en la conducción de ciclomotores o motocicletas. La muestra incluye 4.091 adolescentes de 13 a 18 años, perteneciente a educación secundaria obligatoria. Los resultados obtenidos muestran cuatro perfiles de riesgo, siendo uno de ellos el perfil de más alto riesgo y concurrencia de comportamientos arriesgados. Este grupo supone el 13% en el que destacan las conductas de consumo de drogas lícitas, conducir bajo los efectos de droga y otras conductas realizadas bajo los efectos del alcohol. Se encuentran diferencias entre estos perfiles y las características sociodemográficas como el sexo, el curso, la percepción sobre la economía familiar y

  6. Co-design, co-production, and dissemination of social-ecological knowledge to promote sustainability and resilience: urban experiences from the U.S

    Science.gov (United States)

    J. Morgan Grove; Rinku Roy Chowdhury; Daniel Childers

    2015-01-01

    To promote sustainability and resilience, the role of co-design, co-production, and dissemination of social-ecological knowledge is of growing interest and importance. Although the antecedents for this approach are decades old, the integration of science and practice to advance sustainability and resilience is different from earlier approaches in several ways. In this...

  7. [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.

  8. Parallel implementation of Gray Level Co-occurrence Matrices and Haralick texture features on cell architecture

    NARCIS (Netherlands)

    Shahbahrami, A.; Pham, T.A.; Bertels, K.L.M.

    2011-01-01

    Texture features extraction algorithms are key functions in various image processing applications such as medical images, remote sensing, and content-based image retrieval. The most common way to extract texture features is the use of Gray Level Co-occurrence Matrices (GLCMs). The GLCM contains the

  9. The Co-Occurrence of Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder Symptoms in Parents of Children with ASD or ASD with ADHD

    Science.gov (United States)

    van Steijn, Daphne J.; Richards, Jennifer S.; Oerlemans, Anoek M.; de Ruiter, Saskia W.; van Aken, Marcel A. G.; Franke, Barbara; Buitelaar, Jan. K.; Rommelse, Nanda N. J.

    2012-01-01

    Background: Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) share about 50-72% of their genetic factors, which is the most likely explanation for their frequent co-occurrence within the same patient or family. An additional or alternative explanation for the co-occurrence may be (cross-)assortative mating, e.g.,…

  10. Towards an Ecology of Participation: Process Philosophy and Co-Creation of Higher Education Curricula

    Science.gov (United States)

    Taylor, Carol A.; Bovill, Catherine

    2018-01-01

    This article brings together the authors' previous work on co-created curricula (Bovill, 2013a, 2014; Bovill et al., 2011) and on partnership and ethics (Taylor, 2015; Taylor and Robinson, 2014), to develop the concept of co-created curricula as an ecology of participation. In doing so, it deploys Alfred North Whitehead's process philosophy to…

  11. Transdiagnostic Treatment of Co-occurrence of Anxiety and Depressive Disorders based on Repetitive Negative Thinking: A Case Series

    Directory of Open Access Journals (Sweden)

    Mehdi Akbari

    2015-11-01

    Full Text Available  Objective: The transdiagnostic cognitive behavioral treatments for treating the coexistence of anxiety and mood disorders received useful empirical supports in the recent years. However, these treatments still have moderate efficacy. Following the improvements and developments in transdiagnostic protocols and considering the importance of repetitive negative thinking as a core transdiagnostic factor in emotional disorders, this study examined a new form of transdiagnostic treatment based on Repetitive Negative Thinking (TTRNT of co-occurrence of anxiety and depressive disorders.  Methods:Treatment efficacy was assessed using single case series with multiple baselines. Three patients meeting the criteria for co-occurrence of anxiety and depressive disorders were selected using the Anxiety Disorders Interview Schedule for DSM-IV. The patients were treated individually for 12 weekly sessions. Participants completed the standardized outcome measures during the baseline, treatment and one-month follow-up. Results:At post-treatment, all participants showed significant clinical changes on a range of standardized outcome measures, and these gains were largely maintained through the one-month follow-up both in the principle and co-principal diagnosis. Conclusions:Although the results of this preliminary investigation indicated that TTRNT could be a time effective and efficient treatment for individuals with co-occurrence of anxiety and depressive disorders, further controlled clinical trials are necessary to examine this new treatment approach.

  12. Co-occurrence of arsenic and fluoride in groundwater of semi-arid regions in Latin America: genesis, mobility and remediation.

    Science.gov (United States)

    Alarcón-Herrera, María Teresa; Bundschuh, Jochen; Nath, Bibhash; Nicolli, Hugo B; Gutierrez, Melida; Reyes-Gomez, Victor M; Nuñez, Daniel; Martín-Dominguez, Ignacio R; Sracek, Ondra

    2013-11-15

    Several million people around the world are currently exposed to excessive amounts of arsenic (As) and fluoride (F) in their drinking water. Although the individual toxic effects of As and F have been analyzed, there are few studies addressing their co-occurrences and water treatment options. Several studies conducted in arid and semi-arid regions of Latin America show that the co-occurrences of As and F in drinking water are linked to the volcaniclastic particles in the loess or alluvium, alkaline pH, and limited recharge. The As and F contamination results from water-rock interactions and may be accelerated by geothermal and mining activities, as well as by aquifer over-exploitation. These types of contamination are particularly pronounced in arid and semi-arid regions, where high As concentrations often show a direct relationship with high F concentrations. Enrichment of F is generally related to fluorite dissolution and it is also associated with high Cl, Br, and V concentrations. The methods of As and F removal, such as chemical precipitation followed by filtration and reverse osmosis, are currently being used at different scales and scenarios in Latin America. Although such technologies are available in Latin America, it is still urgent to develop technologies and methods capable of monitoring and removing both of these contaminants simultaneously from drinking water, with a particular focus towards small-scale rural operations. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. A tale of two phylogenies: comparative analyses of ecological interactions.

    Science.gov (United States)

    Hadfield, Jarrod D; Krasnov, Boris R; Poulin, Robert; Nakagawa, Shinichi

    2014-02-01

    The evolution of traits involved in ecological interactions such as predator-prey, host-parasite, and plant-pollinator interactions, are likely to be shaped by the phylogenetic history of both parties. We develop generalized linear mixed-effects models (GLMM) that estimate the effect of both parties' phylogenetic history on trait evolution, both in isolation but also in terms of how the two histories interact. Using data on the incidence and abundance of 206 flea species on 121 mammal species, we illustrate our method and compare it to previously used methods for detecting host-parasite coevolution. At large spatial scales we find that the phylogenetic interaction effect was substantial, indicating that related parasite species were more likely to be found on related host species. At smaller spatial scales, and when sampling effort was not controlled for, phylogenetic effects on the number and types of parasite species harbored by hosts were found to dominate. We go on to show that in situations where these additional phylogenetic effects exist, then previous methods have very high Type I error rates when testing for the phylogenetic interaction. Our GLMM method represents a robust and reliable approach to quantify the phylogenetic effects of traits determined by, or defined by, ecological interactions and has the advantage that it can easily be extended and interpreted in a broader context than existing permutation tests.

  14. Ecology, distribution, and predictive occurrence modeling of Palmers chipmunk (Tamias palmeri): a high-elevation small mammal endemic to the Spring Mountains in southern Nevada, USA

    Science.gov (United States)

    Lowrey, Chris E.; Longshore, Kathleen M.; Riddle, Brett R.; Mantooth, Stacy

    2016-01-01

    Although montane sky islands surrounded by desert scrub and shrub steppe comprise a large part of the biological diversity of the Basin and Range Province of southwestern North America, comprehensive ecological and population demographic studies for high-elevation small mammals within these areas are rare. Here, we examine the ecology and population parameters of the Palmer’s chipmunk (Tamias palmeri) in the Spring Mountains of southern Nevada, and present a predictive GIS-based distribution and probability of occurrence model at both home range and geographic spatial scales. Logistic regression analyses and Akaike Information Criterion model selection found variables of forest type, slope, and distance to water sources as predictive of chipmunk occurrence at the geographic scale. At the home range scale, increasing population density, decreasing overstory canopy cover, and decreasing understory canopy cover contributed to increased survival rates.

  15. Ecological drivers of soil microbial diversity and soil biological networks in the Southern Hemisphere.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Reith, Frank; Dennis, Paul G; Hamonts, Kelly; Powell, Jeff R; Young, Andrew; Singh, Brajesh K; Bissett, Andrew

    2018-03-01

    The ecological drivers of soil biodiversity in the Southern Hemisphere remain underexplored. Here, in a continental survey comprising 647 sites, across 58 degrees of latitude between tropical Australia and Antarctica, we evaluated the major ecological patterns in soil biodiversity and relative abundance of ecological clusters within a co-occurrence network of soil bacteria, archaea and eukaryotes. Six major ecological clusters (modules) of co-occurring soil taxa were identified. These clusters exhibited strong shifts in their relative abundances with increasing distance from the equator. Temperature was the major environmental driver of the relative abundance of ecological clusters when Australia and Antarctica are analyzed together. Temperature, aridity, soil properties and vegetation types were the major drivers of the relative abundance of different ecological clusters within Australia. Our data supports significant reductions in the diversity of bacteria, archaea and eukaryotes in Antarctica vs. Australia linked to strong reductions in temperature. However, we only detected small latitudinal variations in soil biodiversity within Australia. Different environmental drivers regulate the diversity of soil archaea (temperature and soil carbon), bacteria (aridity, vegetation attributes and pH) and eukaryotes (vegetation type and soil carbon) across Australia. Together, our findings provide new insights into the mechanisms driving soil biodiversity in the Southern Hemisphere. © 2018 by the Ecological Society of America.

  16. What can we learn from the microbial ecological interactions associated with polymicrobial diseases?

    Science.gov (United States)

    Antiabong, J F; Boardman, W; Ball, A S

    2014-03-15

    Periodontal diseases in humans and animals are model polymicrobial diseases which are associated with a shift in the microbial community structure and function; there is therefore a need to investigate these diseases from a microbial ecological perspective. This review highlights three important areas of microbial ecological investigation of polymicrobial diseases and the lessons that could be learnt: (1) identification of disease-associated microbes and the implications for choice of anti-infective treatment; (2) the implications associated with vaccine design and development and (3) application of the dynamics of microbial interaction in the discovery of novel anti-infective agents. This review emphasises the need to invigorate microbial ecological approaches to the study of periodontal diseases and other polymicrobial diseases for greater understanding of the ecological interactions between and within the biotic and abiotic factors of the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Tick-Pathogen Ensembles: Do Molecular Interactions Lead Ecological Innovation?

    Czech Academy of Sciences Publication Activity Database

    Cabezas Cruz, Alejandro; Estrada-Peňa, A.; Rego, Ryan O. M.; de la Fuente, J.

    2017-01-01

    Roč. 7, 13 March (2017), č. článku 74. ISSN 2235-2988 Institutional support: RVO:60077344 Keywords : tick-pathogen interactions * transcriptional reprogramming * epigenetics * ecological adaptation * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016

  18. From metabolism to ecology: cross-feeding interactions shape the balance between polymicrobial conflict and mutualism.

    Science.gov (United States)

    Estrela, Sylvie; Trisos, Christopher H; Brown, Sam P

    2012-11-01

    Polymicrobial interactions are widespread in nature and play a major role in maintaining human health and ecosystems. Whenever one organism uses metabolites produced by another organism as energy or nutrient sources, it is called cross-feeding. The ecological outcomes of cross-feeding interactions are poorly understood and potentially diverse: mutualism, competition, exploitation, or commensalism. A major reason for this uncertainty is the lack of theoretical approaches linking microbial metabolism to microbial ecology. To address this issue, we explore the dynamics of a one-way interspecific cross-feeding interaction in which food can be traded for a service (detoxification). Our results show that diverse ecological interactions (competition, mutualism, exploitation) can emerge from this simple cross-feeding interaction and can be predicted by the metabolic, demographic, and environmental parameters that govern the balance of the costs and benefits of association. In particular, our model predicts stronger mutualism for intermediate by-product toxicity because the resource-service exchange is constrained to the service being neither too vital (high toxicity impairs resource provision) nor dispensable (low toxicity reduces need for service). These results support the idea that bridging microbial ecology and metabolism is a critical step toward a better understanding of the factors governing the emergence and dynamics of polymicrobial interactions.

  19. Occurrence of Co-Infection of Helicobacter pullorum and Campylobacter spp. in Broiler and Village (Indigenous Chickens

    Directory of Open Access Journals (Sweden)

    Soe Soe Wai, A. A. Saleha*, Z. Zunita, L. Hassan and A. Jalila

    2012-10-01

    Full Text Available The reports on prevalence of Helicobacter pullorum in broiler chickens are rather limited and lacking in village chickens. This study aimed to determine the occurrence of H. pullorum in broiler and village chickens in Selangor, Malaysia and to report the detection of co-infection of H. pullorum and Campylobacter spp. in these chickens. Village (indigenous chickens were sampled in five markets and broiler chickens from six farms in different localities. Cecal contents were aseptically obtained from the chickens and subjected to three cultural methods. The isolates were identified by biochemical tests and confirmed using a species-specific PCR assay. Helicobacter pullorum were isolated from 25% village chickens and 24.6% broiler chickens, with an overall occurrence of 24.7%. Eleven (50% of these positive chickens (nine in broiler and two in village chickens showed co-infection with Campylobacter spp.

  20. Revisiting the evolution of ecological specialization, with emphasis on insect-plant interactions.

    Science.gov (United States)

    Forister, M L; Dyer, L A; Singer, M S; Stireman, J O; Lill, J T

    2012-05-01

    Ecological specialization is a fundamental and well-studied concept, yet its great reach and complexity limit current understanding in important ways. More than 20 years after the publication of D. J. Futuyma and G. Moreno's oft-cited, major review of the topic, we synthesize new developments in the evolution of ecological specialization. Using insect-plant interactions as a model, we focus on important developments in four critical areas: genetic architecture, behavior, interaction complexity, and macroevolution. We find that theory based on simple genetic trade-offs in host use is being replaced by more subtle and complex pictures of genetic architecture, and multitrophic interactions have risen as a necessary framework for understanding specialization. A wealth of phylogenetic data has made possible a more detailed consideration of the macroevolutionary dimension of specialization, revealing (among other things) bidirectionality in transitions between generalist and specialist lineages. Technological advances, including genomic sequencing and analytical techniques at the community level, raise the possibility that the next decade will see research on specialization spanning multiple levels of biological organization in non-model organisms, from genes to populations to networks of interactions in natural communities. Finally, we offer a set of research questions that we find to be particularly pressing and fruitful for future research on ecological specialization.

  1. Severity and Co-occurrence of Oral and Verbal Apraxias in Left Brain Damaged Adults

    Directory of Open Access Journals (Sweden)

    Fariba Yadegari

    2012-04-01

    Full Text Available Objective: Oral and verbal apraxias represent motor programming deficits of nonverbal and verbal movements respectively. Studying their properties may shed light on speech motor control processes. This study was focused on identifying cases with oral or verbal apraxia, their co–occurrences and severities. Materials & Methods: In this non-experimental study, 55 left adult subjects with left brain lesion including 22 women and 33 men with age range of 23 to 84 years, were examined and videotaped using oral apraxia and verbal apraxia tasks. Three speech and language pathologists independently scored apraxia severities. Data were analyzed by independent t test, Pearson, Phi and Contingency coefficients using SPSS 12. Results: Mean score of oral and verbal apraxias in patients with and without oral and verbal apraxias were significantly different (P<0.001. Forty- two patients had simultaneous oral and verbal apraxias, with significant correlation between their oral and verbal apraxia scores (r=0.75, P<0.001. Six patients showed no oral or verbal apraxia and 7 had just one type of apraxia. Comparison of co-occurrence of two disorders (Phi=0.59 and different oral and verbal intensities (C=0.68 were relatively high (P<0.001. Conclusion: The present research revealed co-occurrence of oral and verbal apraxias to a great extent. It appears that speech motor control is influenced by a more general verbal and nonverbal motor control.

  2. Cross-Surface: Workshop on Interacting with Multi-Device Ecologies in the Wild

    DEFF Research Database (Denmark)

    Houben, Steven; Vermeulen, Jo; Klokmose, Clemens Nylandsted

    2015-01-01

    In this workshop, we will review and discuss opportunities, technical challenges and problems with cross-device interactions in interactive multi-surface and multi-device ecologies. We aim to bring together researchers and practitioners currently working on novel techniques for cross......-surface interactions, identify application domains and enabling technologies for cross-surface interactions in the wild, and establish a research community to develop effective strategies for successful design of cross-device interactions....

  3. Chemical ecology of insect-plant interactions: ecological significance of plant secondary metabolites.

    Science.gov (United States)

    Nishida, Ritsuo

    2014-01-01

    Plants produce a diverse array of secondary metabolites as chemical barriers against herbivores. Many phytophagous insects are highly adapted to these allelochemicals and use such unique substances as the specific host-finding cues, defensive substances of their own, and even as sex pheromones or their precursors by selectively sensing, incorporating, and/or processing these phytochemicals. Insects also serve as pollinators often effectively guided by specific floral fragrances. This review demonstrates the ecological significance of such plant secondary metabolites in the highly diverse interactions between insects and plants.

  4. The co-occurrence of mental disorders in children and adolescents with intellectual disability/intellectual developmental disorder.

    Science.gov (United States)

    Munir, Kerim M

    2016-03-01

    The study summarizes supportive epidemiological data regarding the true co-occurrence (comorbidity) and course of mental disorders in children with intellectual disability/intellectual developmental disorders (ID/IDD) across the lifespan. Published studies involving representative populations of children and adolescents with ID/IDD have demonstrated a three to four-fold increase in prevalence of co-occurring mental disorders. The effect of age, sex, and severity (mild, moderate, severe, and profound) and socioeconomic status on prevalence is currently not clearly understood. To date there are no prevalence estimates of co-occurring mental disorders in youth identified using the new DSM-5 (and proposed ICD-11) definition of ID/IDD using measures of intellectual functions and deficits in adaptive functioning with various severity levels defined on the basis of adaptive functioning, and not intellectual quotient scores. The true relationship between two forms of morbidity remains complex and causal relationships that may be true for one disorder may not apply to another. The new conceptualization of ID/IDD offers a developmentally better informed psychobiological approach that can help distinguish co-occurrence of mental disorders within the neurodevelopmental section with onset during the developmental period as well as the later onset of other mental disorders.

  5. The probability of object-scene co-occurrence influences object identification processes.

    Science.gov (United States)

    Sauvé, Geneviève; Harmand, Mariane; Vanni, Léa; Brodeur, Mathieu B

    2017-07-01

    Contextual information allows the human brain to make predictions about the identity of objects that might be seen and irregularities between an object and its background slow down perception and identification processes. Bar and colleagues modeled the mechanisms underlying this beneficial effect suggesting that the brain stocks information about the statistical regularities of object and scene co-occurrence. Their model suggests that these recurring regularities could be conceptualized along a continuum in which the probability of seeing an object within a given scene can be high (probable condition), moderate (improbable condition) or null (impossible condition). In the present experiment, we propose to disentangle the electrophysiological correlates of these context effects by directly comparing object-scene pairs found along this continuum. We recorded the event-related potentials of 30 healthy participants (18-34 years old) and analyzed their brain activity in three time windows associated with context effects. We observed anterior negativities between 250 and 500 ms after object onset for the improbable and impossible conditions (improbable more negative than impossible) compared to the probable condition as well as a parieto-occipital positivity (improbable more positive than impossible). The brain may use different processing pathways to identify objects depending on whether the probability of co-occurrence with the scene is moderate (rely more on top-down effects) or null (rely more on bottom-up influences). The posterior positivity could index error monitoring aimed to ensure that no false information is integrated into mental representations of the world.

  6. Simulation of climate-tick-host-landscape interactions: Effects of shifts in the seasonality of host population fluctuations on tick densities.

    Science.gov (United States)

    Wang, Hsiao-Hsuan; Grant, W E; Teel, P D; Hamer, S A

    2015-12-01

    Tick vector systems are comprised of complex climate-tick-host-landscape interactions that are difficult to identify and estimate from empirical observations alone. We developed a spatially-explicit, individual-based model, parameterized to represent ecological conditions typical of the south-central United States, to examine effects of shifts in the seasonal occurrence of fluctuations of host densities on tick densities. Simulated shifts in the seasonal occurrence of periods of high and low host densities affected both the magnitude of unfed tick densities and the seasonality of tick development. When shifting the seasonal densities of all size classes of hosts (small, medium, and large) synchronously, densities of nymphs were affected more by smaller shifts away from the baseline host seasonality than were densities of larval and adult life stages. When shifting the seasonal densities of only a single size-class of hosts while holding other size classes at their baseline levels, densities of larval, nymph, and adult life stages responded differently. Shifting seasonal densities of any single host-class earlier resulted in a greater increase in adult tick density than when seasonal densities of all host classes were shifted earlier simultaneously. The mean densities of tick life stages associated with shifts in host densities resulted from system-level interactions of host availability with tick phenology. For example, shifting the seasonality of all hosts ten weeks earlier resulted in an approximately 30% increase in the relative degree of temporal co-occurrence of actively host-seeking ticks and hosts compared to baseline, whereas shifting the seasonality of all hosts ten weeks later resulted in an approximately 70% decrease compared to baseline. Differences among scenarios in the overall presence of active host-seeking ticks in the system were due primarily to the degree of co-occurrence of periods of high densities of unfed ticks and periods of high densities

  7. A Review of Human Health and Ecological Risks due to CO2 Exposure

    Science.gov (United States)

    Hepple, R. P.; Benson, S. M.

    2001-05-01

    This paper presents an overview of the human health and ecological consequences of exposure to elevated levels of carbon dioxide (CO2) in the context of geologic carbon sequestration. The purpose of this effort is to provide a baseline of information to guide future efforts in risk assessment for CO2 sequestration. Scenarios for hazardous CO2 exposure include surface facility leaks, leaks from abandoned or aging wells, and leakage from geologic CO2 storage structures. Amounts of carbon in various reservoirs, systems, and applications were summarized, and the levels of CO2 encountered in nature and everyday life were compared along with physiologically relevant concentrations. Literature pertaining to CO2 occupational exposure limits, regulations, monitoring, and ecological consequences was reviewed. The OSHA, NIOSH, and ACGIH occupational exposure standards are 0.5% CO2 averaged over a 40 hour week, 3% average for a short-term (15 minute) exposure, and 4% as the maximum instantaneous limit considered immediately dangerous to life and health. All three conditions must be satisfied at all times. Any detrimental effects of low-level CO2 exposure are reversible, including the long-term metabolic compensation required by chronic exposure to 3% CO2. Breathing rate doubles at 3% CO2 and is four times the normal rate at 5% CO2. According to occupational exposure and controlled atmosphere research into CO2 toxicology, CO2 is hazardous via direct toxicity at levels above 5%, concentrations not encountered in nature outside of volcanic settings and water-logged soils. Small leaks do not present any danger to people unless the CO2 does not disperse quickly enough through atmospheric mixing but accumulates instead in depressions and confined spaces. These dangers are the result of CO2 being more dense than air. Carbon dioxide is regulated for diverse purposes but never as a toxic substance. Catastrophic incidents involving large amounts and/or rapid release of CO2 such as Lake

  8. Nutritional ecology beyond the individual: a conceptual framework for integrating nutrition and social interactions.

    Science.gov (United States)

    Lihoreau, Mathieu; Buhl, Jerome; Charleston, Michael A; Sword, Gregory A; Raubenheimer, David; Simpson, Stephen J

    2015-03-01

    Over recent years, modelling approaches from nutritional ecology (known as Nutritional Geometry) have been increasingly used to describe how animals and some other organisms select foods and eat them in appropriate amounts in order to maintain a balanced nutritional state maximising fitness. These nutritional strategies profoundly affect the physiology, behaviour and performance of individuals, which in turn impact their social interactions within groups and societies. Here, we present a conceptual framework to study the role of nutrition as a major ecological factor influencing the development and maintenance of social life. We first illustrate some of the mechanisms by which nutritional differences among individuals mediate social interactions in a broad range of species and ecological contexts. We then explain how studying individual- and collective-level nutrition in a common conceptual framework derived from Nutritional Geometry can bring new fundamental insights into the mechanisms and evolution of social interactions, using a combination of simulation models and manipulative experiments. © 2015 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

  9. Occurrence and distribution of Indian primates

    Science.gov (United States)

    Karanth, K.K.; Nichols, J.D.; Hines, J.E.

    2010-01-01

    Global and regional species conservation efforts are hindered by poor distribution data and range maps. Many Indian primates face extinction, but assessments of population status are hindered by lack of reliable distribution data. We estimated the current occurrence and distribution of 15 Indian primates by applying occupancy models to field data from a country-wide survey of local experts. We modeled species occurrence in relation to ecological and social covariates (protected areas, landscape characteristics, and human influences), which we believe are critical to determining species occurrence in India. We found evidence that protected areas positively influence occurrence of seven species and for some species are their only refuge. We found evergreen forests to be more critical for some primates along with temperate and deciduous forests. Elevation negatively influenced occurrence of three species. Lower human population density was positively associated with occurrence of five species, and higher cultural tolerance was positively associated with occurrence of three species. We find that 11 primates occupy less than 15% of the total land area of India. Vulnerable primates with restricted ranges are Golden langur, Arunachal macaque, Pig-tailed macaque, stump-tailed macaque, Phayre's leaf monkey, Nilgiri langur and Lion-tailed macaque. Only Hanuman langur and rhesus macaque are widely distributed. We find occupancy modeling to be useful in determining species ranges, and in agreement with current species ranking and IUCN status. In landscapes where monitoring efforts require optimizing cost, effort and time, we used ecological and social covariates to reliably estimate species occurrence and focus species conservation efforts. ?? Elsevier Ltd.

  10. Testing low cost OEM CO2 sensors for outdoor ecological studies

    Science.gov (United States)

    Macintyre, C. M.; Risk, D. A.

    2011-12-01

    IR (Infrared) gas sensors are used extensively in CO2 research but price and power requirement often limits low-cost distributed sensing. In the past three years, sensors have been introduced to the industrial market at prices as low as $100 US for air-handling and automotive application. These inexpensive sensors are small in size, and have low power demand making them potentially ideal for low-cost distributed deployments. However, the sensors are only tested and calibrated for indoor use and for industrial standards and may not show their true potential for outdoor ecological studies. This poster summarizes the results of a sensor inter-comparison test, to document functionality, response time, electrical noise, precision, and accuracy, under varying moistures and temperatures broadly representative of a wide range of outdoor settings. The three selected sensors were placed in a closed loop system with a valving system using a LiCor Li-7000 as reference, controlled by a CR1000 datalogger that controlled CO2 and moisture concentrations content within the cell on the basis of LiCor readings. To achieve different temperatures, the tests were repeated at room temperature, inside a freezer (-18°C) and incubator (40°C). The tests involved repeatedly stepping the sensors from 2000 ppm CO2 to 400 ppm CO2 in 200 ppm or 400 ppm increments, at various moisture contents, and under the various temperature regimes. Vaisala 222 and 343 sensors were also part of the test group as comparators, as both are used widely in ecological research. The OEM sensors displayed good linearity, fast response time, and results comparable to Vaisala probes. In most cases the sensors performed beyond our expectations with notably less electrical noise than the Vaisala sensors and excellent power thriftiness. Some sensors showed better response to extreme moisture and temperature conditions. Provided that suitable protective embodiments were built around them, and that they are deployed in an

  11. Co-occurrence of Gardnerellavaginalis and Candida sp. in women with and without vulvovaginitis

    Directory of Open Access Journals (Sweden)

    José Eleutério Junior

    2016-07-01

    Full Text Available Aims: To detect the co-occurrence of Gardnerellavaginalis and Candida sp.in women with and without vaginal symptoms. Methods: A cross-sectional study was performed in women seeking treatment in a Brazilian city from March to November 2014. Data, such as age and symptoms, were noted from patients. Vaginal content samples were obtained with a swab of the vaginal wall and were fixed in ATTS (Ambient Temperature Transport System. The Affirm VPIII test (Becton Dickinson and Company, Sparks, MD, USA was used to identify the pathogen. Fisher's exact test with a 95% confidence interval was used for the statistical analysis. Results: In total, 160 women were studied, and 13 cases were excluded. Of the 147 remaining women, fifty-two women were asymptomatic, and 95 women reported symptoms. An association between Gardnerellavaginalis(Gv and Candida sp. (Ca was noted in 9 cases (6.1%. Gv + Ca was observed in 1 case (1.9% in the asymptomatic group and in 12 cases (12.6% in the symptomatic group (p= 0,0361. Vaginal inflammation signs were observed in 8/8 (100% cases of cooccurrence (p<0.005. Conclusion: The co-occurrence of Gardnerellavaginalis and Candida sp. is not rare and is frequently associated with symptoms and mucosal inflammation signs.

  12. Studying the neurobiology of human social interaction: Making the case for ecological validity.

    Science.gov (United States)

    Hogenelst, Koen; Schoevers, Robert A; aan het Rot, Marije

    2015-01-01

    With this commentary we make the case for an increased focus on the ecological validity of the measures used to assess aspects of human social functioning. Impairments in social functioning are seen in many types of psychopathology, negatively affecting the lives of psychiatric patients and those around them. Yet the neurobiology underlying abnormal social interaction remains unclear. As an example of human social neuroscience research with relevance to biological psychiatry and clinical psychopharmacology, this commentary discusses published experimental studies involving manipulation of the human brain serotonin system that included assessments of social behavior. To date, these studies have mostly been laboratory-based and included computer tasks, observations by others, or single-administration self-report measures. Most laboratory measures used so far inform about the role of serotonin in aspects of social interaction, but the relevance for real-life interaction is often unclear. Few studies have used naturalistic assessments in real life. We suggest several laboratory methods with high ecological validity as well as ecological momentary assessment, which involves intensive repeated measures in naturalistic settings. In sum, this commentary intends to stimulate experimental research on the neurobiology of human social interaction as it occurs in real life.

  13. Antibiotics in Crab Ponds of Lake Guchenghu Basin, China: Occurrence, Temporal Variations, and Ecological Risks

    Directory of Open Access Journals (Sweden)

    Wenxia Wang

    2018-03-01

    Full Text Available Antibiotics are widely used in aquaculture, however, this often results in undesirable ecological effects. To evaluate the occurrence, temporal variations, and ecological risk of antibiotics in five crab ponds of Lake Guchenghu Basin, China, 44 antibiotics from nine classes were analyzed by rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS. Twelve antibiotics belonging to six classes were detected in the aqueous phase of five crab ponds, among which sulfonamides and macrolides were the predominant classes, and six compounds (sulfamonomethoxine, sulfadiazine, trimethoprim, erythromycin-H2O, monensin, and florfenicol were frequently detected at high concentrations. In general, the antibiotic levels varied between different crab ponds, with the average concentrations ranging from 122 to 1440 ng/L. The antibiotic concentrations in crab ponds exhibited obvious seasonal variations, with the highest concentration and detection frequency detected in summer. Multivariate analysis showed that antibiotic concentrations were significantly correlated with environmental variables, such as total organic carbon, phosphate, ammonia nitrogen, and pH. Sulfadiazine, clarithromycin, erythromycin-H2O, and ciprofloxacin posed a high risk to algae, while the mixture of antibiotics could pose a high risk to aquatic organisms in the crab ponds. Overall, the usage of antibiotics in farming ponds should be comprehensively investigated and controlled to preserve a healthy aquaculture ecosystem.

  14. A probabilistic approach for estimating the spatial extent of pesticide agricultural use sites and potential co-occurrence with listed species for use in ecological risk assessments.

    Science.gov (United States)

    Budreski, Katherine; Winchell, Michael; Padilla, Lauren; Bang, JiSu; Brain, Richard A

    2016-04-01

    A crop footprint refers to the estimated spatial extent of growing areas for a specific crop, and is commonly used to represent the potential "use site" footprint for a pesticide labeled for use on that crop. A methodology for developing probabilistic crop footprints to estimate the likelihood of pesticide use and the potential co-occurrence of pesticide use and listed species locations was tested at the national scale and compared to alternative methods. The probabilistic aspect of the approach accounts for annual crop rotations and the uncertainty in remotely sensed crop and land cover data sets. The crop footprints used historically are derived exclusively from the National Land Cover Database (NLCD) Cultivated Crops and/or Pasture/Hay classes. This approach broadly aggregates agriculture into 2 classes, which grossly overestimates the spatial extent of individual crops that are labeled for pesticide use. The approach also does not use all the available crop data, represents a single point in time, and does not account for the uncertainty in land cover data set classifications. The probabilistic crop footprint approach described herein incorporates best available information at the time of analysis from the National Agricultural Statistics Service (NASS) Cropland Data Layer (CDL) for 5 y (2008-2012 at the time of analysis), the 2006 NLCD, the 2007 NASS Census of Agriculture, and 5 y of NASS Quick Stats (2008-2012). The approach accounts for misclassification of crop classes in the CDL by incorporating accuracy assessment information by state, year, and crop. The NLCD provides additional information to improve the CDL crop probability through an adjustment based on the NLCD accuracy assessment data using the principles of Bayes' Theorem. Finally, crop probabilities are scaled at the state level by comparing against NASS surveys (Census of Agriculture and Quick Stats) of reported planted acres by crop. In an example application of the new method, the probabilistic

  15. Co2 + interaction with Azospirillum brasilense Sp7 cells: a 57Co emission Mössbauer spectroscopic study

    Science.gov (United States)

    Kamnev, Alexander A.; Tugarova, Anna V.; Biró, Borbála; Kovács, Krisztina; Homonnay, Zoltán; Kuzmann, Ernő; Vértes, Attila

    2012-03-01

    Preliminary 57Co emission Mössbauer spectroscopic data were obtained for the soil bacterium Azospirillum brasilense Sp7 ( T = 80 K) in frozen 57Co2 + -containing suspensions and in their dried residues. The Mössbauer parameters were compared with those for A. brasilense strain Sp245 differing from strain Sp7 by ecological behaviour. Live cells of both strains showed metabolic transformations of 57Co2 + within an hour. Differences in the parameters observed for the two strains under similar conditions suggest dissimilarities in their metabolic response to Co2 + .

  16. Mirid (Hemiptera: Heteroptera) specialists of sticky plants: adaptations, interactions, and ecological implications.

    Science.gov (United States)

    Wheeler, Alfred G; Krimmel, Billy A

    2015-01-07

    Sticky plants-those having glandular trichomes (hairs) that produce adhesive, viscous exudates-can impede the movement of, and entrap, generalist insects. Disparate arthropod groups have adapted to these widespread and taxonomically diverse plants, yet their interactions with glandular hosts rarely are incorporated into broad ecological theory. Ecologists and entomologists might be unaware of even well-documented examples of insects that are sticky-plant specialists. The hemipteran family Miridae (more specifically, the omnivorous Dicyphini: Dicyphina) is the best-known group of arthropods that specializes on sticky plants. In the first synthesis of relationships with glandular plants for any insect family, we review mirid interactions with sticky hosts, including their adaptations (behavioral, morphological, and physiological) and mutualisms with carnivorous plants, and the ecological and agricultural implications of mirid-sticky plant systems. We propose that mirid research applies generally to tritrophic interactions on trichome-defended plants, enhances an understanding of insect-plant interactions, and provides information useful in managing crop pests.

  17. Does spatial co-occurrence of carnivores in a Central European agricultural landscape follow the null model?

    Czech Academy of Sciences Publication Activity Database

    Šálek, Martin; Červinka, J.; Padyšáková, E.; Kreisinger, Jakub

    2014-01-01

    Roč. 60, č. 1 (2014), s. 99-107 ISSN 1612-4642 R&D Projects: GA MŠk LC06073 Institutional support: RVO:68081766 Keywords : Carnivores * Co-occurrence * Interspecific competition * Mesopredator release * Agricultural landscape Subject RIV: EG - Zoology Impact factor: 1.634, year: 2014

  18. Synchronization unveils the organization of ecological networks with positive and negative interactions

    Science.gov (United States)

    Girón, Andrea; Saiz, Hugo; Bacelar, Flora S.; Andrade, Roberto F. S.; Gómez-Gardeñes, Jesús

    2016-06-01

    Network science has helped to understand the organization principles of the interactions among the constituents of large complex systems. However, recently, the high resolution of the data sets collected has allowed to capture the different types of interactions coexisting within the same system. A particularly important example is that of systems with positive and negative interactions, a usual feature appearing in social, neural, and ecological systems. The interplay of links of opposite sign presents natural difficulties for generalizing typical concepts and tools applied to unsigned networks and, moreover, poses some questions intrinsic to the signed nature of the network, such as how are negative interactions balanced by positive ones so to allow the coexistence and survival of competitors/foes within the same system? Here, we show that synchronization phenomenon is an ideal benchmark for uncovering such balance and, as a byproduct, to assess which nodes play a critical role in the overall organization of the system. We illustrate our findings with the analysis of synthetic and real ecological networks in which facilitation and competitive interactions coexist.

  19. Synchronization unveils the organization of ecological networks with positive and negative interactions.

    Science.gov (United States)

    Girón, Andrea; Saiz, Hugo; Bacelar, Flora S; Andrade, Roberto F S; Gómez-Gardeñes, Jesús

    2016-06-01

    Network science has helped to understand the organization principles of the interactions among the constituents of large complex systems. However, recently, the high resolution of the data sets collected has allowed to capture the different types of interactions coexisting within the same system. A particularly important example is that of systems with positive and negative interactions, a usual feature appearing in social, neural, and ecological systems. The interplay of links of opposite sign presents natural difficulties for generalizing typical concepts and tools applied to unsigned networks and, moreover, poses some questions intrinsic to the signed nature of the network, such as how are negative interactions balanced by positive ones so to allow the coexistence and survival of competitors/foes within the same system? Here, we show that synchronization phenomenon is an ideal benchmark for uncovering such balance and, as a byproduct, to assess which nodes play a critical role in the overall organization of the system. We illustrate our findings with the analysis of synthetic and real ecological networks in which facilitation and competitive interactions coexist.

  20. Pollutant threshold concentration determination in marine ecosystems using an ecological interaction endpoint.

    Science.gov (United States)

    Wang, Changyou; Liang, Shengkang; Guo, Wenting; Yu, Hua; Xing, Wenhui

    2015-09-01

    The threshold concentrations of pollutants are determined by extrapolating single-species effect data to community-level effects. This assumes the most sensitive endpoint of the life cycle of individuals and the species sensitivity distribution from single-species toxic effect tests, thus, ignoring the ecological interactions. The uncertainties due to this extrapolation can be partially overcome using the equilibrium point of a customized ecosystem. This method incorporates ecological interactions and integrates the effects on growth, survival, and ingestion into a single effect measure, the equilibrium point excursion in the customized ecosystem, in order to describe the toxic effects on plankton. A case study showed that the threshold concentration of copper calculated with the endpoint of the equilibrium point was 10 μg L(-1), which is significantly different from the threshold calculated with a single-species endpoint. The endpoint calculated using this method provides a more relevant measure of the ecological impact than any single individual-level endpoint. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Exploring the co-evolution of marine ecology and environment in silico

    Science.gov (United States)

    Ridgwell, A.

    2015-12-01

    Species do not live in isolation, but adapt and ultimately, evolve, in relationship with other species as well as with their chemical and physical environment. In the marine environment, this interaction is intimately two-way - the surface biogeochemical environment modulates the makeup of the pelagic ecosystem, yet at the same time, the ecosystem assemblage, by setting the strength of the biological pump and ultimately, in regulating the carbon and nutrient inventory of the ocean and atmospheric pCO2, influences the surface geochemical environment. Feedbacks, both negative and positive, must therefore exist between plankton ecology and global biogeochemical cycles. This has implications for understanding the geological record and particularly the response and recovery of marine ecosystems following major environmental perturbation, but also complicates making projections of future ocean changes. To address a coupled system such as this, new numerical tools are needed as traditional 'functional type' marine ecosystem models are generally incapable of accounting for short-term adaptation, let alone long-term evolution. What is needed is the combination of a plankton model able to simulate a highly diverse ecology plus 'genetic' mutation (changes in trait value(s)) and extinction, *and* an Earth system model capable of simulating long-term evolution of the climatology and geochemistry of the ocean. The Earth system model 'cGENIE' - http://mycgenie.seao2.org generally fills the second criteria, so for this presentation I will focus on the structure of the ecosystem model, the associated methodology, and numerical techniques for dealing with what will turn out to be an exceptionally large number of ocean tracers. If you are really lucky, there may even be some preliminary results :)

  2. Reconstructing past ecological networks: the reconfiguration of seed-dispersal interactions after megafaunal extinction.

    Science.gov (United States)

    Pires, Mathias M; Galetti, Mauro; Donatti, Camila I; Pizo, Marco A; Dirzo, Rodolfo; Guimarães, Paulo R

    2014-08-01

    The late Quaternary megafaunal extinction impacted ecological communities worldwide, and affected key ecological processes such as seed dispersal. The traits of several species of large-seeded plants are thought to have evolved in response to interactions with extinct megafauna, but how these extinctions affected the organization of interactions in seed-dispersal systems is poorly understood. Here, we combined ecological and paleontological data and network analyses to investigate how the structure of a species-rich seed-dispersal network could have changed from the Pleistocene to the present and examine the possible consequences of such changes. Our results indicate that the seed-dispersal network was organized into modules across the different time periods but has been reconfigured in different ways over time. The episode of megafaunal extinction and the arrival of humans changed how seed dispersers were distributed among network modules. However, the recent introduction of livestock into the seed-dispersal system partially restored the original network organization by strengthening the modular configuration. Moreover, after megafaunal extinctions, introduced species and some smaller native mammals became key components for the structure of the seed-dispersal network. We hypothesize that such changes in network structure affected both animal and plant assemblages, potentially contributing to the shaping of modern ecological communities. The ongoing extinction of key large vertebrates will lead to a variety of context-dependent rearranged ecological networks, most certainly affecting ecological and evolutionary processes.

  3. Health benefits, ecological threats of low-carbon electricity

    Science.gov (United States)

    Gibon, Thomas; Hertwich, Edgar G.; Arvesen, Anders; Singh, Bhawna; Verones, Francesca

    2017-03-01

    Stabilizing global temperature will require a shift to renewable or nuclear power from fossil power and the large-scale deployment of CO2 capture and storage (CCS) for remaining fossil fuel use. Non-climate co-benefits of low-carbon energy technologies, especially reduced mortalities from air pollution and decreased ecosystem damage, have been important arguments for policies to reduce CO2 emissions. Taking into account a wide range of environmental mechanisms and the complex interactions of the supply chains of different technologies, we conducted the first life cycle assessment of potential human health and ecological impacts of a global low-carbon electricity scenario. Our assessment indicates strong human health benefits of low-carbon electricity. For ecosystem quality, there is a significant trade-off between reduced pollution and climate impacts and potentially significant ecological impacts from land use associated with increased biopower utilization. Other renewables, nuclear power and CCS show clear ecological benefits, so that the climate mitigation scenario with a relatively low share of biopower has lower ecosystem impacts than the baseline scenario. Energy policy can maximize co-benefits by supporting other renewable and nuclear power and developing biomass supply from sources with low biodiversity impact.

  4. Terrestrial Ecology Section

    International Nuclear Information System (INIS)

    Harris, W.F.

    1978-01-01

    Studies on ecological effects of coal combustion included the following: episodic air pollution stress; interaction of gaseous pollutants and acid precipitation; and brimstone: preliminary results from SO 2 effects on forest growth. Studies on fate and transport of contaminants included deposition of aerosol-associated trace elements to a deciduous forest; hydrologic source areas; and environmental behavior of mercury. The environmental research park is described and forest resource management is discussed. Ecosystem analysis studies included hydrology of Walker branch; water budget of an oak-hickory forest; nutrient release from decaying wood; transpiration of the tulip poplar; and atmospheric CO 2 and its interaction with biospheric changes

  5. Transcriptional interactions suggest niche segregation among microorganisms in the human gut

    DEFF Research Database (Denmark)

    Plichta, Damian Rafal; Juncker, Agnieszka; dos Santos, Marcelo Bertalan Quintanilha

    2016-01-01

    The human gastrointestinal (GI) tract is the habitat for hundreds of microbial species, of which many cannot be cultivated readily, presumably because of the dependencies between species 1. Studies of microbial co-occurrence in the gut have indicated community substructures that may reflect...... functional and metabolic interactions between cohabiting species 2,3. To move beyond species co-occurrence networks, we systematically identified transcriptional interactions between pairs of coexisting gut microbes using metagenomics and microarray-based metatranscriptomics data from 233 stool samples from...

  6. A pharm-ecological perspective of terrestrial and aquatic plant-herbivore interactions.

    Science.gov (United States)

    Forbey, Jennifer Sorensen; Dearing, M Denise; Gross, Elisabeth M; Orians, Colin M; Sotka, Erik E; Foley, William J

    2013-04-01

    We describe some recent themes in the nutritional and chemical ecology of herbivores and the importance of a broad pharmacological view of plant nutrients and chemical defenses that we integrate as "Pharm-ecology". The central role that dose, concentration, and response to plant components (nutrients and secondary metabolites) play in herbivore foraging behavior argues for broader application of approaches derived from pharmacology to both terrestrial and aquatic plant-herbivore systems. We describe how concepts of pharmacokinetics and pharmacodynamics are used to better understand the foraging phenotype of herbivores relative to nutrient and secondary metabolites in food. Implementing these concepts into the field remains a challenge, but new modeling approaches that emphasize tradeoffs and the properties of individual animals show promise. Throughout, we highlight similarities and differences between the historic and future applications of pharm-ecological concepts in understanding the ecology and evolution of terrestrial and aquatic interactions between herbivores and plants. We offer several pharm-ecology related questions and hypotheses that could strengthen our understanding of the nutritional and chemical factors that modulate foraging behavior of herbivores across terrestrial and aquatic systems.

  7. Insect-plant interactions: new pathways to a better comprehension of ecological communities in Neotropical savannas.

    Science.gov (United States)

    Del-Claro, Kleber; Torezan-Silingardi, Helena M

    2009-01-01

    The causal mechanisms shaping and structuring ecological communities are among the most important themes in ecology. The study of insect-plant interactions in trophic nets is pointed out as basic to improve our knowledge on this issue. The cerrado tropical savanna, although extremely diverse, distributed in more than 20% of the Brazilian territory and filled up with rich examples of multitrophic interactions, is underexplored in terms of biodiversity interaction. Here, this ecosystem is suggested as valuable to the study of insect-plant interactions whose understanding can throw a new light at the ecological communities' theory. Three distinct systems: extrafloral nectary plants or trophobiont herbivores and the associated ant fauna; floral herbivores-predators-pollinators; and plants-forest engineers and associated fauna, will serve as examples to illustrate promising new pathways in cerrado. The aim of this brief text is to instigate young researchers, mainly entomologists, to initiate more elaborated field work, including experimental manipulations in multitrophic systems, to explore in an interactive way the structure that maintain preserved viable communities in the Neotropical savanna.

  8. Review: Prevalence and co-occurrence of addictions in US ethnic/racial groups: Implications for genetic research.

    Science.gov (United States)

    Luczak, Susan E; Khoddam, Rubin; Yu, Sheila; Wall, Tamara L; Schwartz, Anna; Sussman, Steve

    2017-08-01

    We conducted a review of the prevalence and co-occurrence of 12 types of addictions in US ethnic/racial groups and discuss the implications of the results for genetic research on addictions. We utilized MEDLINE and PsycINFO databases to review the literature on alcohol, tobacco, marijuana, illicit drugs, gambling, eating/food, internet, sex, love, exercise, work, and shopping. We present results for each addiction based on total US prevalence, prevalence within ethnic groups, and co-occurrence of addictions among ethnic groups when available. This review indicates very little research has examined the interrelationships of addictive behaviors among US ethnic groups. The studies that exist have focused nearly exclusively on comorbidity of substances and gambling behaviors. Overall findings suggest differences among US ethnic groups in prevalence of addictions and in prevalence of addiction among those who use substances or engage in gambling. Almost no ethnic group comparisons of other addictive behaviors including eating/food, internet, love, sex, exercise, work, and shopping were identified in the literature. Despite large-scale research efforts to examine alcohol and substance use disorders in the United States, few studies have been published that examine these addictive behaviors among ethnic groups, and even fewer examine co-occurrence and comorbidity with other addictions. Even with the limited studies, these findings have implications for genetic research on addictive behaviors. We include a discussion of these implications, including issues of population stratification, disaggregation, admixture, and the interplay between genetic and environmental factors in understanding the etiology and treatment of addictions. (Am J Addict 2017;26:424-436). © 2016 American Academy of Addiction Psychiatry.

  9. Co-occurrence of behavioral risk factors of common non-communicable diseases among urban slum dwellers in Nairobi, Kenya.

    Science.gov (United States)

    Haregu, Tilahun Nigatu; Oti, Samuel; Egondi, Thaddaeus; Kyobutungi, Catherine

    2015-01-01

    The four common non-communicable diseases (NCDs) account for 80% of NCD-related deaths worldwide. The four NCDs share four common risk factors. As most of the existing evidence on the common NCD risk factors is based on analysis of a single factor at a time, there is a need to investigate the co-occurrence of the common NCD risk factors, particularly in an urban slum setting in sub-Saharan Africa. To determine the prevalence of co-occurrence of the four common NCDs risk factors among urban slum dwellers in Nairobi, Kenya. This analysis was based on the data collected as part of a cross-sectional survey to assess linkages among socio-economic status, perceived personal risk, and risk factors for cardiovascular and NCDs in a population of slum dwellers in Nairobi, Kenya, in 2008-2009. A total of 5,190 study subjects were included in the analysis. After selecting relevant variables for common NCD risk factors, we computed the prevalence of all possible combinations of the four common NCD risk factors. The analysis was disaggregated by relevant background variables. The weighted prevalences of unhealthy diet, insufficient physical activity, harmful use of alcohol, and tobacco use were found to be 57.2, 14.4, 10.1, and 12.4%, respectively. Nearly 72% of the study participants had at least one of the four NCD risk factors. About 52% of the study population had any one of the four NCD risk factors. About one-fifth (19.8%) had co-occurrence of NCD risk factors. Close to one in six individuals (17.6%) had two NCD risk factors, while only 2.2% had three or four NCD risk factors. One out of five of people in the urban slum settings of Nairobi had co-occurrence of NCD risk factors. Both comprehensive and differentiated approaches are needed for effective NCD prevention and control in these settings.

  10. Seeing Cooperation or Competition: Ecological Interactions in Cultural Perspectives.

    Science.gov (United States)

    Ojalehto, Bethany L; Medin, Douglas L; Horton, William S; Garcia, Salino G; Kays, Estefano G

    2015-10-01

    Do cultural models facilitate particular ways of perceiving interactions in nature? We explore variability in folkecological principles of reasoning about interspecies interactions (specifically, competitive or cooperative). In two studies, Indigenous Panamanian Ngöbe and U.S. participants interpreted an illustrated, wordless nonfiction book about the hunting relationship between a coyote and badger. Across both studies, the majority of Ngöbe interpreted the hunting relationship as cooperative and the majority of U.S. participants as competitive. Study 2 showed that this pattern may reflect different beliefs about, and perhaps different awareness of, plausible interspecies interactions. Further probes suggest that these models of ecological interaction correlate with recognition of social agency (e.g., communication, morality) in nonhuman animals. We interpret our results in terms of cultural models of nature and nonhuman agency. Copyright © 2015 Cognitive Science Society, Inc.

  11. Co{sup 2 + } interaction with Azospirillum brasilense Sp7 cells: a {sup 57}Co emission Moessbauer spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, Alexander A.; Tugarova, Anna V. [Russian Academy of Sciences, Institute of Biochemistry and Physiology of Plants and Microorganisms (Russian Federation); Biro, Borbala [Hungarian Academy of Sciences, Research Institute for Soil Science and Agricultural Chemistry (Hungary); Kovacs, Krisztina, E-mail: kkriszti@chem.elte.hu; Homonnay, Zoltan; Kuzmann, Erno; Vertes, Attila [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

    2012-03-15

    Preliminary {sup 57}Co emission Moessbauer spectroscopic data were obtained for the soil bacterium Azospirillum brasilense Sp7 (T = 80 K) in frozen {sup 57}Co{sup 2 + }-containing suspensions and in their dried residues. The Moessbauer parameters were compared with those for A. brasilense strain Sp245 differing from strain Sp7 by ecological behaviour. Live cells of both strains showed metabolic transformations of {sup 57}Co{sup 2 + } within an hour. Differences in the parameters observed for the two strains under similar conditions suggest dissimilarities in their metabolic response to Co{sup 2 + }.

  12. The co-occurrence of autistic and ADHD dimensions in adults: an etiological study in 17,770 twins.

    NARCIS (Netherlands)

    Polderman, T.J.C.; Hoekstra, R.A.; Posthuma, D.; Larsson, H.

    2014-01-01

    Autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) often occur together. To obtain more insight in potential causes for the co-occurrence, this study examined the genetic and environmental etiology of the association between specific ASD and ADHD disorder dimensions.

  13. Consequences of symbiont co-infections for insect host phenyotypes

    Czech Academy of Sciences Publication Activity Database

    McLean, A. H. C.; Parker, B. J.; Hrček, Jan; Kavanagh, J. C.; Wellham, P. A. D.; Godfray, H. C. J.

    2018-01-01

    Roč. 87, č. 2 (2018), s. 478-488 ISSN 0021-8790 Institutional support: RVO:60077344 Keywords : aphids * co-infection * host-parasite interactions Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.474, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12705/epdf

  14. Prevalence and co-occurrence of violence against children in the Quebec population.

    Science.gov (United States)

    Tourigny, Marc; Hébert, Martine; Joly, Jacques; Cyr, Mireille; Baril, Karine

    2008-08-01

    A literature review on the incidence of different forms of child maltreatment revealed that rates in Australia and Quebec (Canada) were similar. This study sought to determine the prevalence and co-occurrence of various forms of violence (physical, sexual and psychological) and explore gender and age difference. A telephone inquiry was conducted with a representative sample of 1,002 adults from the province of Quebec. More than one in three adults (37%) reported having experienced at least one of three forms of violence in childhood. Twelve per cent (12%) of the adults experienced two forms of violence while 4% of the respondents reported having experienced all three forms of violence in childhood. Psychological violence (22%) was the form most frequently reported, followed by physical violence (19%) and sexual violence (16%). The different prevalence rates did not vary as a function of age. However, regarding gender, women were more likely to report having been sexually victimised (rape and fondling) and less likely to report having experienced physical violence. A lower percentage of women reported having sustained no form of childhood victimisation and a higher percentage of women reported have experienced both sexual and psychological violence compared to men. These results, including both the global rates and those particular to each gender, are comparable to findings in similar North American studies. The co-occurrence rates noted are salient enough to necessitate particular attention to diverse clinical clientele and need to be considered in future research exploring the risk factors of violence and its subsequent repercussions.

  15. 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.

  16. Ecological complexity buffers the impacts of future climate on marine consumers

    Science.gov (United States)

    Goldenberg, Silvan U.; Nagelkerken, Ivan; Marangon, Emma; Bonnet, Angélique; Ferreira, Camilo M.; Connell, Sean D.

    2018-03-01

    Ecological complexity represents a network of interacting components that either propagate or counter the effects of environmental change on individuals and communities1-3. Yet, our understanding of the ecological imprint of ocean acidification (elevated CO2) and climate change (elevated temperature) is largely based on reports of negative effects on single species in simplified laboratory systems4,5. By combining a large mesocosm experiment with a global meta-analysis, we reveal the capacity of consumers (fish and crustaceans) to resist the impacts of elevated CO2. While individual behaviours were impaired by elevated CO2, consumers could restore their performances in more complex environments that allowed for compensatory processes. Consequently, consumers maintained key traits such as foraging, habitat selection and predator avoidance despite elevated CO2 and sustained their populations. Our observed increase in risk-taking under elevated temperature, however, predicts greater vulnerability of consumers to predation. Yet, CO2 as a resource boosted the biomass of consumers through species interactions and may stabilize communities by countering the negative effects of elevated temperature. We conclude that compensatory dynamics inherent in the complexity of nature can buffer the impacts of future climate on species and their communities.

  17. Tritrophic Interactions Mediated by Herbivore-Induced Plant Volatiles: Mechanisms, Ecological Relevance, and Application Potential.

    Science.gov (United States)

    Turlings, Ted C J; Erb, Matthias

    2018-01-07

    Tritrophic interactions between plants, herbivores, and their natural enemies are an integral part of all terrestrial ecosystems. Herbivore-induced plant volatiles (HIPVs) play a key role in these interactions, as they can attract predators and parasitoids to herbivore-attacked plants. Thirty years after this discovery, the ecological importance of the phenomena is widely recognized. However, the primary function of HIPVs is still subject to much debate, as is the possibility of using these plant-produced cues in crop protection. In this review, we summarize the current knowledge on the role of HIPVs in tritrophic interactions from an ecological as well as a mechanistic perspective. This overview focuses on the main gaps in our knowledge of tritrophic interactions, and we argue that filling these gaps will greatly facilitate efforts to exploit HIPVs for pest control.

  18. Ecological interactions in Aedes species on Reunion Island.

    Science.gov (United States)

    Bagny Beilhe, L; Delatte, H; Juliano, S A; Fontenille, D; Quilici, S

    2013-12-01

    Two invasive, container-breeding mosquito species, Aedes aegypti (Stegomyia aegypti) and Aedes albopictus (Stegomyia albopicta) (Diptera: Culicidae), have different distribution patterns on Reunion Island. Aedes albopictus occurs in all areas and Ae. aegypti colonizes only some restricted areas already occupied by Ae. albopictus. This study investigates the abiotic and biotic ecological mechanisms that determine the distribution of Aedes species on Reunion Island. Life history traits (duration of immature stages, survivorship, fecundity, estimated finite rate of increase) in Ae. aegypti and Ae. albopictus were compared at different temperatures. These fitness measures were characterized in both species in response to competitive interactions among larvae. Aedes aegypti was drastically affected by temperature, performing well only at around 25 °C, at which it achieved its highest survivorship and greatest estimated rate of increase. The narrow distribution of this species in the field on Reunion Island may thus relate to its poor ability to cope with unfavourable temperatures. Aedes aegypti was also more negatively affected by high population densities and to some extent by interactions with Ae. albopictus, particularly in the context of limited food supplies. Aedes albopictus exhibited better population performance across a range of environmental conditions. Its ecological plasticity and its superior competitive ability relative to its congener may further enhance its invasion success on Reunion Island. © 2012 The Royal Entomological Society.

  19. Co-adapting societal and ecological interactions following large disturbances in urban park woodlands

    Science.gov (United States)

    Margaret Carreiro; Wayne Zipperer

    2011-01-01

    The responses of urban park woodlands to large disturbances provide the opportunity to identify and examine linkages in social-ecological systems in urban landscapes.We propose that the Panarchy model consisting of hierarchically nested adaptive cycles provides a useful framework to evaluate those linkages.We use two case studies as examples – Cherokee Park in...

  20. ECO: A Framework for Entity Co-Occurrence Exploration with Faceted Navigation

    Energy Technology Data Exchange (ETDEWEB)

    Halliday, K. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-08-20

    Even as highly structured databases and semantic knowledge bases become more prevalent, a substantial amount of human knowledge is reported as written prose. Typical textual reports, such as news articles, contain information about entities (people, organizations, and locations) and their relationships. Automatically extracting such relationships from large text corpora is a key component of corporate and government knowledge bases. The primary goal of the ECO project is to develop a scalable framework for extracting and presenting these relationships for exploration using an easily navigable faceted user interface. ECO uses entity co-occurrence relationships to identify related entities. The system aggregates and indexes information on each entity pair, allowing the user to rapidly discover and mine relational information.

  1. SpeciesGeoCoder: Fast Categorization of Species Occurrences for Analyses of Biodiversity, Biogeography, Ecology, and Evolution.

    Science.gov (United States)

    Töpel, Mats; Zizka, Alexander; Calió, Maria Fernanda; Scharn, Ruud; Silvestro, Daniele; Antonelli, Alexandre

    2017-03-01

    Understanding the patterns and processes underlying the uneven distribution of biodiversity across space constitutes a major scientific challenge in systematic biology and biogeography, which largely relies on effectively mapping and making sense of rapidly increasing species occurrence data. There is thus an urgent need for making the process of coding species into spatial units faster, automated, transparent, and reproducible. Here we present SpeciesGeoCoder, an open-source software package written in Python and R, that allows for easy coding of species into user-defined operational units. These units may be of any size and be purely spatial (i.e., polygons) such as countries and states, conservation areas, biomes, islands, biodiversity hotspots, and areas of endemism, but may also include elevation ranges. This flexibility allows scoring species into complex categories, such as those encountered in topographically and ecologically heterogeneous landscapes. In addition, SpeciesGeoCoder can be used to facilitate sorting and cleaning of occurrence data obtained from online databases, and for testing the impact of incorrect identification of specimens on the spatial coding of species. The various outputs of SpeciesGeoCoder include quantitative biodiversity statistics, global and local distribution maps, and files that can be used directly in many phylogeny-based applications for ancestral range reconstruction, investigations of biome evolution, and other comparative methods. Our simulations indicate that even datasets containing hundreds of millions of records can be analyzed in relatively short time using a standard computer. We exemplify the use of SpeciesGeoCoder by inferring the historical dispersal of birds across the Isthmus of Panama, showing that lowland species crossed the Isthmus about twice as frequently as montane species with a marked increase in the number of dispersals during the last 10 million years. [ancestral area reconstruction; biodiversity

  2. Gender classification from face images by using local binary pattern and gray-level co-occurrence matrix

    Science.gov (United States)

    Uzbaş, Betül; Arslan, Ahmet

    2018-04-01

    Gender is an important step for human computer interactive processes and identification. Human face image is one of the important sources to determine gender. In the present study, gender classification is performed automatically from facial images. In order to classify gender, we propose a combination of features that have been extracted face, eye and lip regions by using a hybrid method of Local Binary Pattern and Gray-Level Co-Occurrence Matrix. The features have been extracted from automatically obtained face, eye and lip regions. All of the extracted features have been combined and given as input parameters to classification methods (Support Vector Machine, Artificial Neural Networks, Naive Bayes and k-Nearest Neighbor methods) for gender classification. The Nottingham Scan face database that consists of the frontal face images of 100 people (50 male and 50 female) is used for this purpose. As the result of the experimental studies, the highest success rate has been achieved as 98% by using Support Vector Machine. The experimental results illustrate the efficacy of our proposed method.

  3. Mechanisms and ecological implications of plant-mediated interactions between belowground and aboveground insect herbivores

    NARCIS (Netherlands)

    Papadopoulou, G.V.; Dam, N.M. van

    2017-01-01

    Plant-mediated interactions between belowground (BG) and aboveground (AG) herbivores have received increasing interest recently. However, the molecular mechanisms underlying ecological consequences of BG–AG interactions are not fully clear yet. Herbivore-induced plant defenses are complex and

  4. 3D shape recovery from image focus using gray level co-occurrence matrix

    Science.gov (United States)

    Mahmood, Fahad; Munir, Umair; Mehmood, Fahad; Iqbal, Javaid

    2018-04-01

    Recovering a precise and accurate 3-D shape of the target object utilizing robust 3-D shape recovery algorithm is an ultimate objective of computer vision community. Focus measure algorithm plays an important role in this architecture which convert the color values of each pixel of the acquired 2-D image dataset into corresponding focus values. After convolving the focus measure filter with the input 2-D image dataset, a 3-D shape recovery approach is applied which will recover the depth map. In this document, we are concerned with proposing Gray Level Co-occurrence Matrix along with its statistical features for computing the focus information of the image dataset. The Gray Level Co-occurrence Matrix quantifies the texture present in the image using statistical features and then applies joint probability distributive function of the gray level pairs of the input image. Finally, we quantify the focus value of the input image using Gaussian Mixture Model. Due to its little computational complexity, sharp focus measure curve, robust to random noise sources and accuracy, it is considered as superior alternative to most of recently proposed 3-D shape recovery approaches. This algorithm is deeply investigated on real image sequences and synthetic image dataset. The efficiency of the proposed scheme is also compared with the state of art 3-D shape recovery approaches. Finally, by means of two global statistical measures, root mean square error and correlation, we claim that this approach -in spite of simplicity generates accurate results.

  5. Co-occurrence of victimization from five subtypes of bullying: physical, verbal, social exclusion, spreading rumors, and cyber.

    Science.gov (United States)

    Wang, Jing; Iannotti, Ronald J; Luk, Jeremy W; Nansel, Tonja R

    2010-11-01

    To examine co-occurrence of five subtypes of peer victimization. Data were obtained from a national sample of 7,475 US adolescents in grades 6 through 10 in the 2005/2006 Health Behavior in School-Aged Children (HBSC) study. Latent class analyses (LCA) were conducted on victimization by physical, verbal, social exclusion, spreading rumors, and cyber bullying. Three latent classes were identified, including an all-types victims class (9.7% of males and 6.2% of females), a verbal/relational victims class (28.1% of males and 35.1% of females), and a nonvictim class (62.2% of males and 58.7% of females). Males were more likely to be all-type victims. There was a graded relationship between the three latent classes and level of depression, frequency of medically attended injuries, and medicine use, especially among females. Increased co-occurrence of victimization types put adolescents at greater risks for poorer physical and psychological outcomes.

  6. The Effect of Phylogeny, Environment and Morphology on Communities of a Lianescent Clade (Bignonieae-Bignoniaceae) in Neotropical Biomes

    Science.gov (United States)

    Alcantara, Suzana; Ree, Richard H.; Martins, Fernando R.; Lohmann, Lúcia G.

    2014-01-01

    The influence of ecological traits to the distribution and abundance of species is a prevalent issue in biodiversity science. Most studies of plant community assembly have focused on traits related to abiotic aspects or direct interactions among plants, with less attention paid to ignore indirect interactions, as those mediated by pollinators. Here, we assessed the influence of phylogeny, habitat, and floral morphology on ecological community structure in a clade of Neotropical lianas (tribe Bignonieae, Bignoniaceae). Our investigation was guided by the long-standing hypothesis that habitat specialization has promoted speciation in Bignonieae, while competition for shared pollinators influences species co-occurrence within communities. We analyzed a geo-referenced database for 94 local communities occurring across the Neotropics. The effect of floral morphological traits and abiotic variables on species co-occurrence was investigated, taking into account phylogenetic relationships. Habitat filtering seems to be the main process driving community assembly in Bignonieae, with environmental conditions limiting species distributions. Differing specialization to abiotic conditions might have evolved recently, in contrast to the general pattern of phylogenetic clustering found in communities of other diverse regions. We find no evidence that competition for pollinators affects species co-occurrence; instead, pollinator occurrence seems to have acted as an “environmental filter” in some habitats. PMID:24594706

  7. Interaction between Allee effects caused by organism-environment feedback and by other ecological mechanisms.

    Directory of Open Access Journals (Sweden)

    Lijuan Qin

    Full Text Available Understanding Allee effect has crucial importance for ecological conservation and management because it is strongly related to population extinction. Due to various ecological mechanisms accounting for Allee effect, it is necessary to study the influence of multiple Allee effects on the dynamics and persistence of population. We here focus on organism-environment feedback which can incur strong, weak, and fatal Allee effect (AE-by-OEF, and further examine their interaction with the Allee effects caused by other ecological mechanisms (AE-by-OM. The results show that multiple Allee effects largely increase the extinction risk of population either due to the enlargement of Allee threshold or the change of inherent characteristic of Allee effect, and such an increase will be enhanced dramatically with increasing the strength of individual Allee effects. Our simulations explicitly considering spatial structure also demonstrate that local interaction among habitat patches can greatly mitigate such superimposed Allee effects as well as individual Allee effect. This implies that spatially structurized habitat could play an important role in ecological conservation and management.

  8. Interaction between Allee effects caused by organism-environment feedback and by other ecological mechanisms.

    Science.gov (United States)

    Qin, Lijuan; Zhang, Feng; Wang, Wanxiong; Song, Weixin

    2017-01-01

    Understanding Allee effect has crucial importance for ecological conservation and management because it is strongly related to population extinction. Due to various ecological mechanisms accounting for Allee effect, it is necessary to study the influence of multiple Allee effects on the dynamics and persistence of population. We here focus on organism-environment feedback which can incur strong, weak, and fatal Allee effect (AE-by-OEF), and further examine their interaction with the Allee effects caused by other ecological mechanisms (AE-by-OM). The results show that multiple Allee effects largely increase the extinction risk of population either due to the enlargement of Allee threshold or the change of inherent characteristic of Allee effect, and such an increase will be enhanced dramatically with increasing the strength of individual Allee effects. Our simulations explicitly considering spatial structure also demonstrate that local interaction among habitat patches can greatly mitigate such superimposed Allee effects as well as individual Allee effect. This implies that spatially structurized habitat could play an important role in ecological conservation and management.

  9. Are there co-occurrence patterns that structure snake communities in Central Brazil? Existem padrões de coocorrência que estruturam comunidades de serpentes no Brasil Central?

    Directory of Open Access Journals (Sweden)

    FGR. França

    2007-02-01

    Full Text Available The main factors that structure Neotropical animal communities have been the subject of discussion in ecology communities. We used a set of null models to investigate the existence of structure in snake communities from the Cerrado in Central Brazil in relation to the co-occurrence of species and guilds concerning specific resources. We used fragments (conservation units inside the Distrito Federal and neighbor municipalities. In spite of recent human colonization in the region from the end of the 1950’s, intense habitat modification and fragmentation has taken place. Sixty three snake species are present in the Distrito Federal. Co-occurrence analysis of species and guilds associated to snake diets and habitats suggested a lack of organization. The homogeneity of habitats in Central Brazil and the minor importance of ecological effects can lead to random arrangement.Os processos que levam à estruturação de comunidades animais neotropicais têm sido sujeito de ampla discussão em ecologia de comunidades. Usou-se um conjunto de modelos nulos para investigar a existência de estrutura em comunidades de serpentes presentes no Cerrado do Brasil Central, em relação à coocorrência de espécies e de guildas relacionadas a recursos específicos. As localidades utilizadas para as análises representam fragmentos de habitats dentro do Distrito Federal e em municípios vizinhos. Apesar da recente colonização humana da região, datada para o final da década de 50, a intensidade da modificação e fragmentação dos habitats no Brasil Central têm sido enorme. Sessenta e três espécies de serpentes estão presentes no Distrito Federal. As análises dos padrões de coocorrência tanto para as espécies quanto para guildas relativas à dieta e ao uso do ambiente sugeriram ausência de organização. A homogeneidade dos ambientes no Brasil Central e a baixa importância de efeitos ecológicos podem levar ao arranjo randômico.

  10. Egocentric interaction as a tool for designing ambient ecologies – The case of the easy ADL ecology

    DEFF Research Database (Denmark)

    Surie, Dipak; Janlert, Lars-Erik; Pederson, Thomas

    2012-01-01

    ambient intelligence could be realised. This work describes such an ambient ecological system comprising of a set of smart everyday objects, a personal activity-centric middleware, a set of mock-up ubiquitous computing applications and a human agent within a living laboratory home environment......Ambient intelligence is a human-centered vision characterized by the seamless integration of information, communication, sensing and actuation, and interface technologies for supporting human agents with their everyday activities. There are many challenges to address including the need...... for an interaction paradigm that encompasses the multiple dimensions of a human agent and their environment. This work describes a human-centered interaction paradigm referred to as the egocentric interaction paradigm that considers a human agents body and mind as a centre of reference to which all interaction...

  11. Mycotoxigenic Fungi and Natural Co-Occurrence of Mycotoxins in Rainbow Trout (Oncorhynchus mykiss Feeds

    Directory of Open Access Journals (Sweden)

    Mariana Greco

    2015-11-01

    Full Text Available Samples of rainbow trout feed were analyzed with the aim to determine the mycobiota composition and the co-occurrence of mycotoxins. A total of 28 samples of finished rainbow trout feed from hatcheries in the provinces of Río Negro and Neuquén, Argentina, were studied. Fungal counts were obtained on three culture media in the ranges of <10 to 4.2 × 104 CFU/g on Dichloran Rose Bengal Chloramphenicol Agar (DRBC, <10 to 5.1 × 104 CFU/g on Dichloran Chloramphenicol Peptone Agar (DCPA and <10 to 3.6 × 104 CFU/g on Dichloran 18% Glycerol Agar (DG18. The most frequent mycotoxigenic fungi were Eurotium (frequency (Fr 25.0%, followed by Penicillium (Fr 21.4% and Aspergillus (Fr 3.6%. The most prevalent mycotoxigenic species were E. repens (Fr 21.4% and E. rubrum (Fr 14.3%. All samples were contaminated with mycotoxins: 64% samples were contaminated with T-2 toxin (median 70.08 ppb, 50% samples with zearalenone (median 87.97 ppb and aflatoxins (median 2.82 ppb, 25% with ochratoxin A (median 5.26 ppb and 3.57% samples with deoxynivalenol (median 230 ppb. Eight samples had a fumonisins contamination level below the limit of detection. Co-occurrence of six mycotoxins was determined in 7% of the samples.

  12. Effects of CO2 and temperature on tritrophic interactions.

    Directory of Open Access Journals (Sweden)

    Lee A Dyer

    Full Text Available There has been a significant increase in studies of how global change parameters affect interacting species or entire communities, yet the combined or interactive effects of increased atmospheric CO2 and associated increases in global mean temperatures on chemically mediated trophic interactions are mostly unknown. Thus, predictions of climate-induced changes on plant-insect interactions are still based primarily on studies of individual species, individual global change parameters, pairwise interactions, or parameters that summarize communities. A clear understanding of community response to global change will only emerge from studies that examine effects of multiple variables on biotic interactions. We examined the effects of increased CO2 and temperature on simple laboratory communities of interacting alfalfa, chemical defense, armyworm caterpillars, and parasitoid wasps. Higher temperatures and CO2 caused decreased plant quality, decreased caterpillar development times, developmental asynchrony between caterpillars and wasps, and complete wasp mortality. The effects measured here, along with other effects of global change on natural enemies suggest that biological control and other top-down effects of insect predators will decline over the coming decades.

  13. Adolescent Fathers Who Are Incarcerated Juvenile Offenders: Explanatory Study of the Co-Occurrence of Two Problem Behaviors

    Science.gov (United States)

    Unruh, Deanne; Bullis, Michael; Yovanoff, Paul

    2004-01-01

    We identify explanatory risk variables associated with the co-occurrence of two problem behaviors: juvenile offending and adolescent fatherhood. Data were gathered from a 5-year prospective, longitudinal study of 531 incarcerated juvenile offenders as they transitioned from youth correction facilities back into the community. Of the total sample,…

  14. The influence of the interactions between anthropogenic activities and multiple ecological factors on land surface temperatures of urban forests

    Science.gov (United States)

    Ren, Y.

    2017-12-01

    Context Land surface temperatures (LSTs) spatio-temporal distribution pattern of urban forests are influenced by many ecological factors; the identification of interaction between these factors can improve simulations and predictions of spatial patterns of urban cold islands. This quantitative research requires an integrated method that combines multiple sources data with spatial statistical analysis. Objectives The purpose of this study was to clarify urban forest LST influence interaction between anthropogenic activities and multiple ecological factors using cluster analysis of hot and cold spots and Geogdetector model. We introduced the hypothesis that anthropogenic activity interacts with certain ecological factors, and their combination influences urban forests LST. We also assumed that spatio-temporal distributions of urban forest LST should be similar to those of ecological factors and can be represented quantitatively. Methods We used Jinjiang as a representative city in China as a case study. Population density was employed to represent anthropogenic activity. We built up a multi-source data (forest inventory, digital elevation models (DEM), population, and remote sensing imagery) on a unified urban scale to support urban forest LST influence interaction research. Through a combination of spatial statistical analysis results, multi-source spatial data, and Geogdetector model, the interaction mechanisms of urban forest LST were revealed. Results Although different ecological factors have different influences on forest LST, in two periods with different hot spots and cold spots, the patch area and dominant tree species were the main factors contributing to LST clustering in urban forests. The interaction between anthropogenic activity and multiple ecological factors increased LST in urban forest stands, linearly and nonlinearly. Strong interactions between elevation and dominant species were generally observed and were prevalent in either hot or cold spots

  15. Dental biofilm: ecological interactions in health and disease.

    Science.gov (United States)

    Marsh, P D; Zaura, Egija

    2017-03-01

    The oral microbiome is diverse and exists as multispecies microbial communities on oral surfaces in structurally and functionally organized biofilms. To describe the network of microbial interactions (both synergistic and antagonistic) occurring within these biofilms and assess their role in oral health and dental disease. PubMed database was searched for studies on microbial ecological interactions in dental biofilms. The search results did not lend themselves to systematic review and have been summarized in a narrative review instead. Five hundred and forty-seven original research articles and 212 reviews were identified. The majority (86%) of research articles addressed bacterial-bacterial interactions, while inter-kingdom microbial interactions were the least studied. The interactions included physical and nutritional synergistic associations, antagonism, cell-to-cell communication and gene transfer. Oral microbial communities display emergent properties that cannot be inferred from studies of single species. Individual organisms grow in environments they would not tolerate in pure culture. The networks of multiple synergistic and antagonistic interactions generate microbial inter-dependencies and give biofilms a resilience to minor environmental perturbations, and this contributes to oral health. If key environmental pressures exceed thresholds associated with health, then the competitiveness among oral microorganisms is altered and dysbiosis can occur, increasing the risk of dental disease. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. What do we know about child abuse and neglect patterns of co-occurrence? A systematic review of profiling studies and recommendations for future research.

    Science.gov (United States)

    Debowska, Agata; Willmott, Dominic; Boduszek, Daniel; Jones, Adele D

    2017-08-01

    Latent class (LCA) and latent profile (LPA) analysis represent methodological approaches to identify subgroups of maltreated individuals. Although research examining child abuse and neglect (CAN) profiles is still rare, the application of person-centered techniques to clarify CAN types co-occurrence has substantially increased in recent years. Therefore, the aim of the present study was to provide a summary and critical evaluation of the findings of LCA/LPA child maltreatment research to: (a) systemize the current understanding of patterns of maltreatment across populations and (b) elucidate interactive effects of CAN types on psychosocial functioning. A search in PsychInfo, Eric, PubMed, Scopus, and Science Direct, and Google Scholar was performed. Sixteen studies examining the co-occurrence between child physical abuse, emotional abuse, sexual abuse, neglect, and/or exposure to domestic violence were identified. A critical review of the studies revealed inconsistent findings as to the number of CAN classes, but most research uncovered a poly-victimized and a low abuse group. Further, multiple victimization was associated with most adverse internalizing and externalizing outcomes, especially when sexual abuse was present. Exposure to physical and emotional abuse was frequently reported to lead to behavioural problems. Based on the present study results, we provide a set of recommendations for surpassing the current methodological and conceptual limitations in future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Co-occurrence of linguistic and biological diversity in biodiversity hotspots and high biodiversity wilderness areas.

    Science.gov (United States)

    Gorenflo, L J; Romaine, Suzanne; Mittermeier, Russell A; Walker-Painemilla, Kristen

    2012-05-22

    As the world grows less biologically diverse, it is becoming less linguistically and culturally diverse as well. Biologists estimate annual loss of species at 1,000 times or more greater than historic rates, and linguists predict that 50-90% of the world's languages will disappear by the end of this century. Prior studies indicate similarities in the geographic arrangement of biological and linguistic diversity, although conclusions have often been constrained by use of data with limited spatial precision. Here we use greatly improved datasets to explore the co-occurrence of linguistic and biological diversity in regions containing many of the Earth's remaining species: biodiversity hotspots and high biodiversity wilderness areas. Results indicate that these regions often contain considerable linguistic diversity, accounting for 70% of all languages on Earth. Moreover, the languages involved are frequently unique (endemic) to particular regions, with many facing extinction. Likely reasons for co-occurrence of linguistic and biological diversity are complex and appear to vary among localities, although strong geographic concordance between biological and linguistic diversity in many areas argues for some form of functional connection. Languages in high biodiversity regions also often co-occur with one or more specific conservation priorities, here defined as endangered species and protected areas, marking particular localities important for maintaining both forms of diversity. The results reported in this article provide a starting point for focused research exploring the relationship between biological and linguistic-cultural diversity, and for developing integrated strategies designed to conserve species and languages in regions rich in both.

  18. State and business co-operation in settling socio-economic issues: forward to sustainable development of ecologically unfavorable regions

    Science.gov (United States)

    Bashkirova, N. N.; Lessovaia, S. N.

    2018-01-01

    The complexity of socio-economic issues of mono-cities located in the ecologically unfavorable regions of Eurasia was disclosed. The economically strategic role of city-forming mining enterprises and their impact on ecological situation was revealed. The general conception of settling the socio-economic problems of mono-cities located in ecologically unfavorable regions was worked out. Various approached to the concentration of financial resources for economic and ecological sustainable development of the regions located on the north of Eurasia holding nature protection actions were submitted. Based on performed critical analysis of the positive international experience of ecological taxation some approaches to reforming current Russian system of ecological taxation were suggested. It was revealed that increasing the social responsibilities of business in the field of waste recycling, environmental protection and monitoring of ecological conditions of territories and state and business co-operation are the most efficient opportunities in settling socio-economic issues of ecologically unfavorable regions.

  19. Prevalence and co-occurrence of addictive behaviors among former alternative high school youth.

    Science.gov (United States)

    Sussman, Steve; Arpawong, Thalida Em; Sun, Ping; Tsai, Jennifer; Rohrbach, Louise A; Spruijt-Metz, Donna

    2014-04-01

    Recent work has studied multiple addictions using a matrix measure, which taps multiple addictions through single responses for each type. The present study investigated use of a matrix measure approach among former alternative high school youth (average age = 19.8 years) at risk for addictions. Lifetime and last 30-day prevalence of one or more of 11 addictions reviewed in other work (Sussman, Lisha & Griffiths, 2011) was the primary focus (i.e., cigarettes, alcohol, other/hard drugs, eating, gambling, Internet, shopping, love, sex, exercise, and work). Also, the co-occurrence of two or more of these 11 addictive behaviors was investigated. Finally, the latent class structure of these addictions, and their associations with other measures, was examined. We found that ever and last 30-day prevalence of one or more of these addictions was 79.2% and 61.5%, respectively. Ever and last 30-day co-occurrence of two or more of these addictions was 61.5% and 37.7%, respectively. Latent Class Analysis suggested two groups: a generally Non-addicted Group (67.2% of the sample) and a "Work Hard, Play Hard"-addicted Group that was particularly invested in addiction to love, sex, exercise, the Internet, and work. Supplementary analyses suggested that the single-response type self-reports may be measuring the addictions they intend to measure. We suggest implications of these results for future studies and the development of prevention and treatment programs, though much more validation research is needed on the use of this type of measure.

  20. Co2 +  interaction with Azospirillum brasilense Sp7 cells: a 57Co emission Mössbauer spectroscopic study

    International Nuclear Information System (INIS)

    Kamnev, Alexander A.; Tugarova, Anna V.; Biró, Borbála; Kovács, Krisztina; Homonnay, Zoltán; Kuzmann, Ernő; Vértes, Attila

    2012-01-01

    Preliminary 57 Co emission Mössbauer spectroscopic data were obtained for the soil bacterium Azospirillum brasilense Sp7 (T = 80 K) in frozen 57 Co 2 +  -containing suspensions and in their dried residues. The Mössbauer parameters were compared with those for A. brasilense strain Sp245 differing from strain Sp7 by ecological behaviour. Live cells of both strains showed metabolic transformations of 57 Co 2 +  within an hour. Differences in the parameters observed for the two strains under similar conditions suggest dissimilarities in their metabolic response to Co 2 +  .

  1. 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...

  2. Comparison of varying operating parameters on heavy metals ecological risk during anaerobic co-digestion of chicken manure and corn stover.

    Science.gov (United States)

    Yan, Yilong; Zhang, Liqiu; Feng, Li; Sun, Dezhi; Dang, Yan

    2018-01-01

    In this study, the potential ecological risk of heavy metals (Mn, Zn, Cu, Ni, As, Cd, Pb, Cr) accumulation from anaerobic co-digestion of chicken manure (CM) and corn stover (CS) was evaluated by comparing different initial substrate concentrations, digestion temperatures, and mixture ratios. Results showed that the highest volumetric methane yield of 20.3±1.4L/L reactor was achieved with a CS:CM ratio of 3:1 (on volatile solid basis) in mesophilic solid state anaerobic digestion (SS-AD). Although co-digestion increased the concentrations of all tested heavy metals and the direct toxicity of some heavy metals, the potential ecological risk index indicated that the digestates were all classified as low ecological risk. The biogasification and risk variation of heavy metals were affected by the operating parameters. These results are significant and should be taken into consideration when optimizing co-digestion of animal manure and crop residues during full-scale projects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Response of Two Mytilids to a Heatwave: The Complex Interplay of Physiology, Behaviour and Ecological Interactions.

    Science.gov (United States)

    Olabarria, Celia; Gestoso, Ignacio; Lima, Fernando P; Vázquez, Elsa; Comeau, Luc A; Gomes, Filipa; Seabra, Rui; Babarro, José M F

    2016-01-01

    Different combinations of behavioural and physiological responses may play a crucial role in the ecological success of species, notably in the context of biological invasions. The invasive mussel Xenostrobus securis has successfully colonised the inner part of the Galician Rias Baixas (NW Spain), where it co-occurs with the commercially-important mussel Mytilus galloprovincialis. This study investigated the effect of a heatwave on the physiological and behavioural responses in monospecific or mixed aggregations of these species. In a mesocosm experiment, mussels were exposed to simulated tidal cycles and similar temperature conditions to those experienced in the field during a heat-wave that occurred in the summer of 2013, when field robo-mussels registered temperatures up to 44.5°C at low tide. The overall responses to stress differed markedly between the two species. In monospecific aggregations M. galloprovincialis was more vulnerable than X. securis to heat exposure during emersion. However, in mixed aggregations, the presence of the invader was associated with lower mortality in M. galloprovincialis. The greater sensitivity of M. galloprovincialis to heat exposure was reflected in a higher mortality level, greater induction of Hsp70 protein and higher rates of respiration and gaping activity, which were accompanied by a lower heart rate (bradycardia). The findings show that the invader enhanced the physiological performance of M. galloprovincialis, highlighting the importance of species interactions in regulating responses to environmental stress. Understanding the complex interactions between ecological factors and physiological and behavioural responses of closely-related species is essential for predicting the impacts of invasions in the context of future climate change.

  4. The co-occurrence of physical and cyber dating violence and bullying among teens.

    Science.gov (United States)

    Yahner, Jennifer; Dank, Meredith; Zweig, Janine M; Lachman, Pamela

    2015-04-01

    This study examined the overlap in teen dating violence and bullying perpetration and victimization, with regard to acts of physical violence, psychological abuse, and-for the first time ever-digitally perpetrated cyber abuse. A total of 5,647 youth (51% female, 74% White) from 10 schools participated in a cross-sectional anonymous survey. Results indicated substantial co-occurrence of all types of teen dating violence and bullying. Youth who perpetrated and/or experienced physical, psychological, and cyber bullying were likely to have also perpetrated/experienced physical and sexual dating violence, and psychological and cyber dating abuse. © The Author(s) 2014.

  5. Novel keyword co-occurrence network-based methods to foster systematic reviews of scientific literature.

    Science.gov (United States)

    Radhakrishnan, Srinivasan; Erbis, Serkan; Isaacs, Jacqueline A; Kamarthi, Sagar

    2017-01-01

    Systematic reviews of scientific literature are important for mapping the existing state of research and highlighting further growth channels in a field of study, but systematic reviews are inherently tedious, time consuming, and manual in nature. In recent years, keyword co-occurrence networks (KCNs) are exploited for knowledge mapping. In a KCN, each keyword is represented as a node and each co-occurrence of a pair of words is represented as a link. The number of times that a pair of words co-occurs in multiple articles constitutes the weight of the link connecting the pair. The network constructed in this manner represents cumulative knowledge of a domain and helps to uncover meaningful knowledge components and insights based on the patterns and strength of links between keywords that appear in the literature. In this work, we propose a KCN-based approach that can be implemented prior to undertaking a systematic review to guide and accelerate the review process. The novelty of this method lies in the new metrics used for statistical analysis of a KCN that differ from those typically used for KCN analysis. The approach is demonstrated through its application to nano-related Environmental, Health, and Safety (EHS) risk literature. The KCN approach identified the knowledge components, knowledge structure, and research trends that match with those discovered through a traditional systematic review of the nanoEHS field. Because KCN-based analyses can be conducted more quickly to explore a vast amount of literature, this method can provide a knowledge map and insights prior to undertaking a rigorous traditional systematic review. This two-step approach can significantly reduce the effort and time required for a traditional systematic literature review. The proposed KCN-based pre-systematic review method is universal. It can be applied to any scientific field of study to prepare a knowledge map.

  6. Co-creating value through agents interaction within service network

    International Nuclear Information System (INIS)

    Okdinawati, L.; Simatupang, T.M.; Sunitiyoso, Y.

    2017-01-01

    The purpose of this paper is to gives further understanding on value co-creation mechanisms in B-to-B service network by reinforcing the processes, the relationships, and influences of other agents where Collaborative Transportation Management (CTM) forms might be best employed. Design/methodology/approach: In order to model the interactions among agents in the collaboration processes and the value co-creation processes, this research used three collaboration cases in Indonesia. Then, the agent-based simulation was used to capture both the collaboration process and the value co-creation process of the three collaboration cases. Findings: The interactions among the agents both inside and outside their collaboration environment determined agent’s role as a value co-creator. The willingness of an agent to accept the opinion of another agent determined the degree of their willingness to co-operate and to change their strategies, and perceptions. Therefore, influenced the size of the value obtained by them in each collaboration process. Research limitations/implications: The findings of the simulations subject to assumptions based on the collaboration cases. Further research is related to how to encourage agents to co-operate and adjust their perceptions. Practical implications: It is crucial for the practitioners to interact with another agent both inside and outside their collaboration environment. The opinions of another agent inside the collaboration environment also need to be considered. Originality/value: This research is derived from its emphasis on how a value is co-created by reinforcing both the collaborative processes and the interactions among agents as well as on how CTM might be best employed.

  7. Co-creating value through agents interaction within service network

    Energy Technology Data Exchange (ETDEWEB)

    Okdinawati, L.; Simatupang, T.M.; Sunitiyoso, Y.

    2017-07-01

    The purpose of this paper is to gives further understanding on value co-creation mechanisms in B-to-B service network by reinforcing the processes, the relationships, and influences of other agents where Collaborative Transportation Management (CTM) forms might be best employed. Design/methodology/approach: In order to model the interactions among agents in the collaboration processes and the value co-creation processes, this research used three collaboration cases in Indonesia. Then, the agent-based simulation was used to capture both the collaboration process and the value co-creation process of the three collaboration cases. Findings: The interactions among the agents both inside and outside their collaboration environment determined agent’s role as a value co-creator. The willingness of an agent to accept the opinion of another agent determined the degree of their willingness to co-operate and to change their strategies, and perceptions. Therefore, influenced the size of the value obtained by them in each collaboration process. Research limitations/implications: The findings of the simulations subject to assumptions based on the collaboration cases. Further research is related to how to encourage agents to co-operate and adjust their perceptions. Practical implications: It is crucial for the practitioners to interact with another agent both inside and outside their collaboration environment. The opinions of another agent inside the collaboration environment also need to be considered. Originality/value: This research is derived from its emphasis on how a value is co-created by reinforcing both the collaborative processes and the interactions among agents as well as on how CTM might be best employed.

  8. Towards a Social-Ecological Urbanism: Co-Producing Knowledge through Design in the Albano Resilient Campus Project in Stockholm

    Directory of Open Access Journals (Sweden)

    Hanna Erixon Aalto

    2018-03-01

    Full Text Available If we are to promote urban sustainability and resilience, social-ecological knowledge must be better integrated in urban planning and design projects. Due to gaps in the two cultures of thinking that are associated with the disciplines of ecology and design, such integration has, however, proven to be challenging. In mainstream practice, ecologists often act as sub-consultants; they are seldom engaged in the creative and conceptual phases of the process. Conversely, research aiming to bridge the gap between design and ecology has tended to be dominated by a relatively static and linear outlook on what the design process is, and what it could be. Further, few concrete examples of the co-production of ecological and design knowledge exist. In this paper, we give an account of a transdisciplinary design proposal for Albano Resilient Campus in Stockholm, discussing how design—seen as a process and an assemblage of artifacts—can act as a framework for co-producing knowledge and operationalizing concepts of resilience and ecosystem services. Through a design-based and action-oriented approach, we discuss how such a collaborative design process may integrate ecological knowledge into urban design through three concrete practices: (a iterative prototyping; (b generative matrix models; and, (c legible, open-ended, comprehensive narratives. In the conclusion, we sketch the contours of a social-ecological urbanism, speculating on possible broader and changed roles for ecologists, designers, and the associated actors within this framework.

  9. Hi-C Chromatin Interaction Networks Predict Co-expression in the Mouse Cortex

    Science.gov (United States)

    Hulsman, Marc; Lelieveldt, Boudewijn P. F.; de Ridder, Jeroen; Reinders, Marcel

    2015-01-01

    The three dimensional conformation of the genome in the cell nucleus influences important biological processes such as gene expression regulation. Recent studies have shown a strong correlation between chromatin interactions and gene co-expression. However, predicting gene co-expression from frequent long-range chromatin interactions remains challenging. We address this by characterizing the topology of the cortical chromatin interaction network using scale-aware topological measures. We demonstrate that based on these characterizations it is possible to accurately predict spatial co-expression between genes in the mouse cortex. Consistent with previous findings, we find that the chromatin interaction profile of a gene-pair is a good predictor of their spatial co-expression. However, the accuracy of the prediction can be substantially improved when chromatin interactions are described using scale-aware topological measures of the multi-resolution chromatin interaction network. We conclude that, for co-expression prediction, it is necessary to take into account different levels of chromatin interactions ranging from direct interaction between genes (i.e. small-scale) to chromatin compartment interactions (i.e. large-scale). PMID:25965262

  10. Co-occurrence dynamics of endangered Lower Keys marsh rabbits and free-ranging domestic cats: Prey responses to an exotic predator removal program.

    Science.gov (United States)

    Cove, Michael V; Gardner, Beth; Simons, Theodore R; O'Connell, Allan F

    2018-04-01

    The Lower Keys marsh rabbit ( Sylvilagus palustris hefneri ) is one of many endangered endemic species of the Florida Keys. The main threats are habitat loss and fragmentation from sea-level rise, development, and habitat succession. Exotic predators such as free-ranging domestic cats ( Felis catus ) pose an additional threat to these endangered small mammals. Management strategies have focused on habitat restoration and exotic predator control. However, the effectiveness of predator removal and the effects of anthropogenic habitat modifications and restoration have not been evaluated. Between 2013 and 2015, we used camera traps to survey marsh rabbits and free-ranging cats at 84 sites in the National Key Deer Refuge, Big Pine Key, Florida, USA. We used dynamic occupancy models to determine factors associated with marsh rabbit occurrence, colonization, extinction, and the co-occurrence of marsh rabbits and cats during a period of predator removal. Rabbit occurrence was positively related to freshwater habitat and patch size, but was negatively related to the number of individual cats detected at each site. Furthermore, marsh rabbit colonization was negatively associated with relative increases in the number of individual cats at each site between survey years. Cat occurrence was negatively associated with increasing distance from human developments. The probability of cat site extinction was positively related to a 2-year trapping effort, indicating that predator removal reduced the cat population. Dynamic co-occurrence models suggested that cats and marsh rabbits co-occur less frequently than expected under random conditions, whereas co-detections were site and survey-specific. Rabbit site extinction and colonization were not strongly conditional on cat presence, but corresponded with a negative association. Our results suggest that while rabbits can colonize and persist at sites where cats occur, it is the number of individual cats at a site that more strongly

  11. Interactions between CO2, saline water and minerals during geological storage of CO2

    International Nuclear Information System (INIS)

    Hellevang, Helge

    2006-06-01

    The topic of this thesis is to gain a better understanding of interactions between injected CO 2 , aqueous solutions and formation mineralogies. The main focus is concerned with the potential role mineral reactions play in safe long term storage of CO 2 . The work is divided into an experimental part concentrated on the potential of dawsonite (NaAl(OH) 2 CO 3 ) as a permanent storage host of CO 2 , and the development of a new geochemical code ACCRETE that is coupled with the ATHENA multiphase flow simulator. The thesis is composed of two parts: (I) the first part introducing CO 2 storage, geochemical interactions and related work; and (II) the second part that consists of the papers. Part I is composed as follows: Chapter 2 gives a short introduction to geochemical reactions considered important during CO 2 storage, including a thermodynamic framework. Chapter 3 presents objectives of numerical work related to CO 2 -water-rock interactions including a discussion of factors that influence the outcome of numerical simulations. Chapter 4 presents the main results from paper A to E. Chapter 5 give some details about further research that we propose based on the present work and related work in the project. Several new activities have emerged from research on CO 2 -water-rock interaction during the project. Several of the proposed activities are already initiated. Papers A to F are then listed in Part II of the thesis after the citation list. The thesis presents the first data on the reaction kinetics of dawsonite at different pH (Paper A), and comprehensive numerical simulations, both batch- and large scale 3D reactive transport, that illustrate the role different carbonates have for safe storage of CO 2 in geological formations (Papers C to F). The role of dawsonite in CO 2 storage settings is treated throughout the study (Papers A to E) After the main part of the thesis (Part I and II), two appendices are included: Appendix A lists reactions that are included in the

  12. The co-optimization of floral display and nectar reward

    Indian Academy of Sciences (India)

    Prakash

    2009-12-10

    Dec 10, 2009 ... Flowers may lure pollinators by making large floral displays. (Ohashi and ... Pollination biology; plant–animal interaction; co-evolution; cheater; pollinator learning ..... cheater flowers optimized according to the local ecological.

  13. Comparison of long-term geochemical interactions at two natural CO2-analogues : Montmiral (Southeast Basin, France) and Messokampos (Florina Basin, Greece) case studies

    International Nuclear Information System (INIS)

    Gaus, I.; Le Guern, C.; Pauwels, H.; Pearce, J.; Shepherd, T.; Hatziyannis, G.; Metaxas, A.

    2005-01-01

    Carbon dioxide (CO 2 ) capture and storage is considered to be a viable strategy to reduce the amount of greenhouse gases released to the atmosphere. When assessing the feasibility of current or future CO 2 storage projects, mineral trapping within a reservoir is considered as a key mechanism for the permanent sequestration of CO 2 . There are many occurrences worldwide, where natural CO 2 has been trapped in geological reservoirs. These natural CO 2 analogues provide a unique opportunity to study the reactivity, due to CO 2 interactions, which occurred in the reservoirs over a geologic timeframe. Therefore, the study of analogous natural CO 2 -rich reservoirs, which act as long-term laboratories, are an important part of the assessment of the long-term geochemical effects of geological CO 2 storage. This paper referred to 2 natural CO 2 sites studied under the Natural Analogues for the Storage of CO2 in the Geological Environment (NASCENT) Project. The Montmiral reservoir in France's Southeast Basin is a high-temperature and high-pressure reservoir at great depth (100 degrees C and 36 MPa). The Messokampos reservoir in Greece's Florina Basin is a shallow, low temperature and low-pressure reservoir (25 degrees C and 0.5 MPa). Both are sandstone reservoirs, and feldspar alteration is the key interaction in both cases between dissolved CO 2 , the formation water and the reservoir rock. Both natural analogues were studied in detail petrographically and through geochemical modelling in order to characterize and explain the water-rock-gas interactions in the different geological contexts. The purpose was to assess the consequences of these interactions on CO 2 storage capacity and porosity of the host rock. It was concluded that the reservoir's temperature and pressure conditions determine the impact of CO 2 interactions, with elevated temperatures significantly increasing the reaction rates of mineral-trapping reactions. This is particularly significant when choosing

  14. Formal Models of the Network Co-occurrence Underlying Mental Operations.

    Science.gov (United States)

    Bzdok, Danilo; Varoquaux, Gaël; Grisel, Olivier; Eickenberg, Michael; Poupon, Cyril; Thirion, Bertrand

    2016-06-01

    Systems neuroscience has identified a set of canonical large-scale networks in humans. These have predominantly been characterized by resting-state analyses of the task-unconstrained, mind-wandering brain. Their explicit relationship to defined task performance is largely unknown and remains challenging. The present work contributes a multivariate statistical learning approach that can extract the major brain networks and quantify their configuration during various psychological tasks. The method is validated in two extensive datasets (n = 500 and n = 81) by model-based generation of synthetic activity maps from recombination of shared network topographies. To study a use case, we formally revisited the poorly understood difference between neural activity underlying idling versus goal-directed behavior. We demonstrate that task-specific neural activity patterns can be explained by plausible combinations of resting-state networks. The possibility of decomposing a mental task into the relative contributions of major brain networks, the "network co-occurrence architecture" of a given task, opens an alternative access to the neural substrates of human cognition.

  15. Tic disorders: administrative prevalence and co-occurrence with attention-deficit/hyperactivity disorder in a German community sample.

    Science.gov (United States)

    Schlander, M; Schwarz, O; Rothenberger, A; Roessner, V

    2011-09-01

    Coexistence of tics and attention-deficit/hyperactivity disorder (ADHD) has important clinical and scientific implications. Existing data on the co-occurrence of tic disorders, Tourette Syndrome (TS), and ADHD are largely derived from small-scale studies in selected samples and therefore heterogeneous. The Nordbaden project captures the complete outpatient claims data of more than 2.2 million persons, representing 82% of the regional population in 2003. Based upon the number of diagnosed cases of tic disorders, TS, and ADHD, we determined 12-months administrative prevalence rates as well as rates of co-occurrence. Both tic disorders and ADHD were diagnosed most often in the age group 7-12 years (any tic disorder: 0.8%; ADHD: 5.0%). With increasing age, the administrative prevalence difference in favor of males disappeared, with tic disorders being somewhat more frequently reported in females than males in the age groups above 30 years. The highest rate of ADHD co-occurring with tic disorders was found in adolescents (age 13-18 years, 15.1%). Tic disorders were observed in 2.3% of patients with ADHD. Administrative prevalence rates of tic disorders and TS were substantially lower compared to rates found in community-based epidemiological studies, suggesting that a large number of cases remain undetected and untreated under present conditions of routine outpatient care. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  16. Effort-reward imbalance at work and the co-occurrence of lifestyle risk factors: cross-sectional survey in a sample of 36,127 public sector employees

    OpenAIRE

    Kouvonen, Anne; Kivimäki, Mika; Virtanen, Marianna; Heponiemi, Tarja; Elovainio, Marko; Pentti, Jaana; Linna, Anne; Vahtera, Jussi

    2006-01-01

    Abstract Background In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI) model – effort, rewards and ERI – are associated with the co-occurrence of lifestyle risk factors. Methods Based on data from the Finnish Pu...

  17. PPI finder: a mining tool for human protein-protein interactions.

    Directory of Open Access Journals (Sweden)

    Min He

    Full Text Available BACKGROUND: The exponential increase of published biomedical literature prompts the use of text mining tools to manage the information overload automatically. One of the most common applications is to mine protein-protein interactions (PPIs from PubMed abstracts. Currently, most tools in mining PPIs from literature are using co-occurrence-based approaches or rule-based approaches. Hybrid methods (frame-based approaches by combining these two methods may have better performance in predicting PPIs. However, the predicted PPIs from these methods are rarely evaluated by known PPI databases and co-occurred terms in Gene Ontology (GO database. METHODOLOGY/PRINCIPAL FINDINGS: We here developed a web-based tool, PPI Finder, to mine human PPIs from PubMed abstracts based on their co-occurrences and interaction words, followed by evidences in human PPI databases and shared terms in GO database. Only 28% of the co-occurred pairs in PubMed abstracts appeared in any of the commonly used human PPI databases (HPRD, BioGRID and BIND. On the other hand, of the known PPIs in HPRD, 69% showed co-occurrences in the literature, and 65% shared GO terms. CONCLUSIONS: PPI Finder provides a useful tool for biologists to uncover potential novel PPIs. It is freely accessible at http://liweilab.genetics.ac.cn/tm/.

  18. Microbes in the coral holobiont: partners through evolution, development, and ecological interactions.

    Science.gov (United States)

    Thompson, Janelle R; Rivera, Hanny E; Closek, Collin J; Medina, Mónica

    2014-01-01

    In the last two decades, genetic and genomic studies have revealed the astonishing diversity and ubiquity of microorganisms. Emergence and expansion of the human microbiome project has reshaped our thinking about how microbes control host health-not only as pathogens, but also as symbionts. In coral reef environments, scientists have begun to examine the role that microorganisms play in coral life history. Herein, we review the current literature on coral-microbe interactions within the context of their role in evolution, development, and ecology. We ask the following questions, first posed by McFall-Ngai et al. (2013) in their review of animal evolution, with specific attention to how coral-microbial interactions may be affected under future environmental conditions: (1) How do corals and their microbiome affect each other's genomes? (2) How does coral development depend on microbial partners? (3) How is homeostasis maintained between corals and their microbial symbionts? (4) How can ecological approaches deepen our understanding of the multiple levels of coral-microbial interactions? Elucidating the role that microorganisms play in the structure and function of the holobiont is essential for understanding how corals maintain homeostasis and acclimate to changing environmental conditions.

  19. [Co-occurrence of anxiety and autism. The social error and allostatic load hypotheses].

    Science.gov (United States)

    Paula-Perez, Isabel

    2013-02-22

    INTRODUCTION. The concept of comorbidity in neurodevelopmental disorders like autism is sometimes ambiguous. The co-occurrence of anxiety and autism is clinically significant, yet it is not always easy to determine whether it is a 'real' comorbidity, where the two comorbid conditions are phenotypically and aetiologically identical to what that anxiety would mean in persons with a neurotypical development, whether it is an anxiety that has been phenotypically modified by the pathological processes of the autism spectrum disorders, thus resulting in a specific variant of these latter, or whether we are dealing with a false comorbidity resulting from rather inaccurate differential diagnoses. DEVELOPMENT. The article puts forward two hypotheses to explain this co-occurrence, which provide each other with feedback and are little more than our reflections on the scientific evidence we have available today, but expressed aloud. The first is the 'social error' hypothesis, which considers that the maladjustments in the social behaviour of persons with autism (which arises from alterations affecting the processes involved in social cognition) help to aggravate anxiety in autism. The second hypothesis, referring to allostatic load, holds that anxiety is a response to chronic stress, wear or exhaustion that is produced by the hyperactivation of certain structures in the limbic system. CONCLUSIONS. The prototypical manifestations of anxiety present in the person with autism are not always related with the same biopsychosocial variables as those observed in persons without autism. Evidence points to hyper-reactive flee-or-fight responses (hypervigilance) when the person finds him or herself outside their comfort zone, and supports the hypotheses of 'social error' and of decompensation of the allostatic mechanism that makes it possible to cope with stress.

  20. 77 FR 40088 - Rollins College; T.A. Loving Co.; US Ecology Idaho, Inc.; and West Pharmaceutical Services, Inc...

    Science.gov (United States)

    2012-07-06

    ...] Rollins College; T.A. Loving Co.; US Ecology Idaho, Inc.; and West Pharmaceutical Services, Inc... Pharmaceutical Services, Inc. V-77-9 01/20/1978 43 FR 2945 1910.217(c)(3)(i)(e) and (formerly The West Co.). 1910... the variance (Ex. 2--OSHA-2012-0024). 3. West Pharmaceutical Services, Inc. The Agency granted The...

  1. Prokaryotes in subsoil – evidence for spatial separation of oligotrophs and copiotrophs by co-occurrence networks

    Directory of Open Access Journals (Sweden)

    Michael eSchloter

    2015-11-01

    Full Text Available Soil microbial communities provide a wide range of soil functions including nutrient cycling, soil formation, and plant growth promotion. On the small scale, nutrient rich soil hotspots developed from soil animal or plant activity are important drivers for microbial communities and their activity pattern. Nevertheless, in subsoil, the spatial heterogeneity of microbes with diverging lifestyles has been barely considered so far. In this study, the phylogenetic composition of the bacterial and archaeal microbiome based on 16S rRNA gene pyrosequencing was investigated in the soil compartments bulk soil, drilosphere, and rhizosphere in topsoil and in the subsoil of an agricultural field. With co-occurrence network analysis, the spatial separation of typically oligotrophs and heterotrophs in subsoil and hotspots was assessed. Four co-occurring bacterial communities were identified and attributed to bulk topsoil, bulk subsoil, drilosphere, and rhizosphere. The bacterial phyla Proteobacteria and Bacteroidetes, which represent many copiotrophic bacteria, are affiliated to the hotspot communities – the rhizosphere and drilosphere – both in topsoil and subsoil. Acidobacteria, Actinobacteria, Gemmatimonadetes, Planctomycetes, and Verrucomicrobia with many oligotrophic bacteria, are the abundant groups of the bulk subsoil community. The bacterial core microbiome in this soil was estimated and only covers 7.6% of the bacterial sequencing reads but includes both oligotrophic and copiotrophic bacteria. Instead, the archaeal core microbiome includes 56% of the overall archaeal diversity and comprises only the ammonium oxidizing Nitrososphaera. Thus, the spatial variability of nutrient quality and quantity strongly shapes the bacterial community composition and their interaction in subsoil, whereas archaea are a stable backbone of the soil prokaryotes.

  2. Occurrence and distribution of Staphylococcus aureus lineages among zoo animals

    DEFF Research Database (Denmark)

    Gongora, Carmen Espinosa; Chrobak, Dorota; Moodley, Arshnee

    2012-01-01

    The current knowledge of the occurrence and diversity of Staphylococcus aureus in animals is largely biased in favour MRSA and domestic animals. In order to generate novel information on the ecology and population structure of this bacterial species in the animal kingdom, we investigated...... the occurrence and genotypic diversity of S. aureus in a range of animal species kept at the Copenhagen Zoo. We sampled 146 animals belonging to 25 mammalian species and 21 reptiles belonging to six species. A total of 59 S. aureus isolates were found in 10 of the 25 mammalian species tested. All isolates were...... MSSA belonging to fourteen spa types, including three novel spa types. MLST revealed the occurrence of seven STs. The study of the ecology of commensal S. aureus in captive wild animals revealed that ST133 has a broader host range than previously thought....

  3. Predicting Avian Influenza Co-Infection with H5N1 and H9N2 in Northern Egypt

    Directory of Open Access Journals (Sweden)

    Sean G. Young

    2016-09-01

    Full Text Available Human outbreaks with avian influenza have been, so far, constrained by poor viral adaptation to non-avian hosts. This could be overcome via co-infection, whereby two strains share genetic material, allowing new hybrid strains to emerge. Identifying areas where co-infection is most likely can help target spaces for increased surveillance. Ecological niche modeling using remotely-sensed data can be used for this purpose. H5N1 and H9N2 influenza subtypes are endemic in Egyptian poultry. From 2006 to 2015, over 20,000 poultry and wild birds were tested at farms and live bird markets. Using ecological niche modeling we identified environmental, behavioral, and population characteristics of H5N1 and H9N2 niches within Egypt. Niches differed markedly by subtype. The subtype niches were combined to model co-infection potential with known occurrences used for validation. The distance to live bird markets was a strong predictor of co-infection. Using only single-subtype influenza outbreaks and publicly available ecological data, we identified areas of co-infection potential with high accuracy (area under the receiver operating characteristic (ROC curve (AUC 0.991.

  4. Automated experimentation in ecological networks.

    Science.gov (United States)

    Lurgi, Miguel; Robertson, David

    2011-05-09

    In ecological networks, natural communities are studied from a complex systems perspective by representing interactions among species within them in the form of a graph, which is in turn analysed using mathematical tools. Topological features encountered in complex networks have been proved to provide the systems they represent with interesting attributes such as robustness and stability, which in ecological systems translates into the ability of communities to resist perturbations of different kinds. A focus of research in community ecology is on understanding the mechanisms by which these complex networks of interactions among species in a community arise. We employ an agent-based approach to model ecological processes operating at the species' interaction level for the study of the emergence of organisation in ecological networks. We have designed protocols of interaction among agents in a multi-agent system based on ecological processes occurring at the interaction level between species in plant-animal mutualistic communities. Interaction models for agents coordination thus engineered facilitate the emergence of network features such as those found in ecological networks of interacting species, in our artificial societies of agents. Agent based models developed in this way facilitate the automation of the design an execution of simulation experiments that allow for the exploration of diverse behavioural mechanisms believed to be responsible for community organisation in ecological communities. This automated way of conducting experiments empowers the study of ecological networks by exploiting the expressive power of interaction models specification in agent systems.

  5. Negative, neutral, and positive interactions among nonnative plants: patterns, processes, and management implications.

    Science.gov (United States)

    Kuebbing, Sara E; Nuñez, Martin A

    2015-02-01

    The movement of species is one of the most pervasive forms of global change, and few ecosystems remain uninvaded by nonnative species. Studying species interactions is crucial for understanding their distribution and abundance, particularly for nonnative species because interactions may influence the probability of invasion and consequent ecological impact. Interactions among nonnatives are relatively understudied, though the likelihood of nonnative species co-occurrence is high. We quantify and describe the types of interactions among nonnative plants and determine what factors affect interaction outcomes for ecosystems globally. We reviewed 65 studies comprising 201 observations and recorded the interaction type, traits of the interacting species, and study characteristics. We conducted a census of interaction types and a meta-analysis of experiments that tested nonnative competition intensity. Both methods showed that negative and neutral interactions prevailed, and a number of studies reported that the removal of a dominant nonnative led to competitive release of other nonnatives. Positive interactions were less frequently reported and positive mean effect sizes were rare, but the plant characteristics nitrogen fixation, life cycle (annual or perennial), and functional group significantly influenced positive interactions. Positive interactions were three times more frequent when a neighboring nonnative was a nitrogen fixer and 3.5 times lower when a neighboring nonnative was an annual. Woody plants were two or four times more likely to have positive interactions relative to grasses or herbs, respectively. The prevalence of negative interactions suggests that managers should prepare for reinvasion of sites when treating dominant nonnatives. Though positive interactions were infrequent, managers may be able to anticipate positive interactions among nonnatives based upon traits of the co-occurring invaders. Predicting positive nonnative interactions is an

  6. Simulation of CO2–water–rock interactions on geologic CO2 sequestration under geological conditions of China

    International Nuclear Information System (INIS)

    Wang, Tianye; Wang, Huaiyuan; Zhang, Fengjun; Xu, Tianfu

    2013-01-01

    Highlights: • We determined the feasibilities of geologic CO 2 sequestration in China. • We determined the formation of gibbsite suggested CO 2 can be captured by rocks. • We suggested the mechanisms of CO 2 –water–rock interactions. • We found the corrosion and dissolution of the rock increased as temperature rose. -- Abstract: The main purpose of this study focused on the feasibility of geologic CO 2 sequestration within the actual geological conditions of the first Carbon Capture and Storage (CCS) project in China. This study investigated CO 2 –water–rock interactions under simulated hydrothermal conditions via physicochemical analyses and scanning electron microscopy (SEM). Mass loss measurement and SEM showed that corrosion of feldspars, silica, and clay minerals increased with increasing temperature. Corrosion of sandstone samples in the CO 2 -containing fluid showed a positive correlation with temperature. During reaction at 70 °C, 85 °C, and 100 °C, gibbsite (an intermediate mineral product) formed on the sample surface. This demonstrated mineral capture of CO 2 and supported the feasibility of geologic CO 2 sequestration. Chemical analyses suggested a dissolution–reprecipitation mechanism underlying the CO 2 –water–rock interactions. The results of this study suggested that mineral dissolution, new mineral precipitation, and carbonic acid formation-dissociation are closely interrelated in CO 2 –water–rock interactions

  7. Linking macroecology and community ecology: refining predictions of species distributions using biotic interaction networks.

    Science.gov (United States)

    Staniczenko, Phillip P A; Sivasubramaniam, Prabu; Suttle, K Blake; Pearson, Richard G

    2017-06-01

    Macroecological models for predicting species distributions usually only include abiotic environmental conditions as explanatory variables, despite knowledge from community ecology that all species are linked to other species through biotic interactions. This disconnect is largely due to the different spatial scales considered by the two sub-disciplines: macroecologists study patterns at large extents and coarse resolutions, while community ecologists focus on small extents and fine resolutions. A general framework for including biotic interactions in macroecological models would help bridge this divide, as it would allow for rigorous testing of the role that biotic interactions play in determining species ranges. Here, we present an approach that combines species distribution models with Bayesian networks, which enables the direct and indirect effects of biotic interactions to be modelled as propagating conditional dependencies among species' presences. We show that including biotic interactions in distribution models for species from a California grassland community results in better range predictions across the western USA. This new approach will be important for improving estimates of species distributions and their dynamics under environmental change. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  8. 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....

  9. Response of Two Mytilids to a Heatwave: The Complex Interplay of Physiology, Behaviour and Ecological Interactions.

    Directory of Open Access Journals (Sweden)

    Celia Olabarria

    Full Text Available Different combinations of behavioural and physiological responses may play a crucial role in the ecological success of species, notably in the context of biological invasions. The invasive mussel Xenostrobus securis has successfully colonised the inner part of the Galician Rias Baixas (NW Spain, where it co-occurs with the commercially-important mussel Mytilus galloprovincialis. This study investigated the effect of a heatwave on the physiological and behavioural responses in monospecific or mixed aggregations of these species. In a mesocosm experiment, mussels were exposed to simulated tidal cycles and similar temperature conditions to those experienced in the field during a heat-wave that occurred in the summer of 2013, when field robo-mussels registered temperatures up to 44.5°C at low tide. The overall responses to stress differed markedly between the two species. In monospecific aggregations M. galloprovincialis was more vulnerable than X. securis to heat exposure during emersion. However, in mixed aggregations, the presence of the invader was associated with lower mortality in M. galloprovincialis. The greater sensitivity of M. galloprovincialis to heat exposure was reflected in a higher mortality level, greater induction of Hsp70 protein and higher rates of respiration and gaping activity, which were accompanied by a lower heart rate (bradycardia. The findings show that the invader enhanced the physiological performance of M. galloprovincialis, highlighting the importance of species interactions in regulating responses to environmental stress. Understanding the complex interactions between ecological factors and physiological and behavioural responses of closely-related species is essential for predicting the impacts of invasions in the context of future climate change.

  10. Co-occurrence analysis of microbial taxa in the Atlantic Ocean reveals high connectivity in the free-living bacterioplankton

    Directory of Open Access Journals (Sweden)

    Mathias eMilici

    2016-05-01

    Full Text Available We determined the taxonomic composition of the bacterioplankton of the epipelagic zone of the Atlantic Ocean along a latitudinal transect (51°S – 47°N using Illumina sequencing of the V5-V6 region of the 16S rRNA gene and inferred co-occurrence networks. Bacterioplankon community composition was distinct for Longhurstian provinces and water depth. Free-living microbial communities (between 0.22-3 µm were dominated by highly abundant and ubiquitous taxa with streamlined genomes (e.g. SAR11, SAR86, OM1, Prochlorococcus and could clearly be separated from particle-associated communities which were dominated by Bacteroidetes, Planktomycetes, Verrucomicrobia and Roseobacters. From a total of 369 different communities we then inferred co-occurrence networks for each size fraction and depth layer of the plankton between bacteria and between bacteria and phototrophic micro-eukaryotes. The inferred networks showed a reduction of edges in the deepest layer of the photic zone. Networks comprised of free-living bacteria had a larger amount of connections per OTU when compared to the particle associated communities throughout the water column. Negative correlations accounted for roughly one third of the total edges in the free-living communities at all depths, while they decreased with depth in the particle associated communities where they amounted for roughly 10% of the total in the last part of the epipelagic zone. Co-occurrence networks of bacteria with phototrophic micro-eukaryotes were not taxon-specific, and dominated by mutual exclusion (~60%. The data show a high degree of specialization to micro-environments in the water column and highlight the importance of interdependencies particularly between free-living bacteria in the upper layers of the epipelagic zone.

  11. The repository ecology an approach to understanding repository and service interactions

    CERN Document Server

    CERN. Geneva; Hagemann, Melissa

    2007-01-01

    An increasing number of university institutions and other organisations are deciding to deploy repositories and a growing number of formal and informal distributed services are supporting or capitalising on the information these repositories provide. Despite reasonably well understood technical architectures, early majority adopters may struggle to articulate their place within the actualities of a wider information environment. The idea of a repository ecology provides developers and administrators with a useful way of articulating and analysing their place in the information environment, and the technical and organisational interactions they have, or are developing, with other parts of such an environment. This presentation will provide an overview of the concept of a repository ecology and examine some examples from the domains of scholarly communications and elearning.

  12. [Case report of rare co-occurrence of renal cell carcinoma and crossed renal dystopia (L-shaped kidney)].

    Science.gov (United States)

    Bakov, V N; Los, M S

    2017-10-01

    L-shaped kidney refers to a rare anomaly of the relative kidney positioning. Due to low prevalence, the literature on the co-occurrence of this anomaly with malignancy is lacking. And, if the diagnosis of a renal anomaly does not present difficulties, if a tumor is detected in such a kidney, even MSCT does not always help differentiate a pelvic tumor from a tumor of the renal parenchyma spreading to the pelvicalyceal system. This has important implications for choosing an appropriate surgical strategy. A feature of the presented clinical observation is the co-occurrence of the rare anomaly of kidney position and locally advanced renal cell carcinoma spreading to the renal pelvis. Due to the massive spread of the tumor, an organ-sparing surgery was not feasible. Due to the suspicion of tumor spread to the renal pelvis, the patient underwent nephrureterectomy of the L-shaped kidney. Introduction to renoprival state with transfer to chronic hemodialysis became the only option to maintain homeostasis and extend the patients life. Histological examination revealed clear cell renal cell carcinoma with invasion of the pelvis and renal capsule, with no clear demarcation between the fused kidneys.

  13. Ecological assessment of agricultural co-substrates for biogas production; Oekologische Bewertung der Bereitstellung landwirtschaftlicher Kosubstrate zur Biogaserzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Ploechl, M; Heiermann, M [Abt. Technikbewertung und Stoffkreislauefe, Inst. fuer Agrartechnik Bomim, Potsdam (Germany)

    2002-07-01

    This paper presents the results of simplified life cycle assessments (LCA) of the cultivation of a variety of crops suitable for biogas production. The simplification refers to that only greenhouse gases and the cumulated energy requirements (CER) are regarded. The values for the greenhouse gas emissions expressed as CO{sub 2} equivalents are around 130 g CO{sub 2}eq.kg{sup -1} ODM with lowest value of 75.5 g CO{sub 2}eq.kg{sup -1} ODM for hemp (Cannabis sativa) and the highest value of 170 g CO{sub 2}eq.kg{sup -1} ODM for rape (Brassica napus). Considering electric power as final product and referring therefore on kWh as unit the differences become even greater, mainly because of the different methane production potentials. On this basis the lowest value amounts to 84 g CO{sub 2}eq.kWh{sup -1} for alfalfa (Medicago sativa) and the highest value amounts to 438 g CO{sub 2}eq.kWh{sup -1} for rape. This general trend that the LCA identifies hemp, forage grass (Dactylis, Lolium and Festuca species), alfalfa, and maize (Zea mays) to have a low ecologic input and rape to have a high ecologic input is confirmed regarding the CER. The CER values are lowest with 0.82 MJ.kWh{sup -1} for maize and forage grass and highest with 3.47 MJ.kWh{sup -1} for rape. (orig.)

  14. The ecology, evolution, impacts and management of host-parasite interactions of marine molluscs.

    Science.gov (United States)

    Coen, Loren D; Bishop, Melanie J

    2015-10-01

    Molluscs are economically and ecologically important components of aquatic ecosystems. In addition to supporting valuable aquaculture and wild-harvest industries, their populations determine the structure of benthic communities, cycling of nutrients, serve as prey resources for higher trophic levels and, in some instances, stabilize shorelines and maintain water quality. This paper reviews existing knowledge of the ecology of host-parasite interactions involving marine molluscs, with a focus on gastropods and bivalves. It considers the ecological and evolutionary impacts of molluscan parasites on their hosts and vice versa, and on the communities and ecosystems in which they are a part, as well as disease management and its ecological impacts. An increasing number of case studies show that disease can have important effects on marine molluscs, their ecological interactions and ecosystem services, at spatial scales from centimeters to thousands of kilometers and timescales ranging from hours to years. In some instances the cascading indirect effects arising from parasitic infection of molluscs extend well beyond the temporal and spatial scales at which molluscs are affected by disease. In addition to the direct effects of molluscan disease, there can be large indirect impacts on marine environments resulting from strategies, such as introduction of non-native species and selective breeding for disease resistance, put in place to manage disease. Much of our understanding of impacts of molluscan diseases on the marine environment has been derived from just a handful of intensively studied marine parasite-host systems, namely gastropod-trematode, cockle-trematode, and oyster-protistan interactions. Understanding molluscan host-parasite dynamics is of growing importance because: (1) expanding aquaculture; (2) current and future climate change; (3) movement of non-native species; and (4) coastal development are modifying molluscan disease dynamics, ultimately leading to

  15. Hydrogen interactions with ZrCo nanoclusters: a first-principles study

    International Nuclear Information System (INIS)

    Chattaraj, D.; Parida, S.C.; Dash, Smruti; Bhattacharya, Saswata; Majumder, C.

    2014-01-01

    Tritium is one of the fuels going to be used in fusion reactor program. But, this radioactive isotope should be stored safely. ZrCo intermetallic has been chosen as a tritium storage material in ITER program. It is important to study how hydrogen interacts with ZrCo in its different dimensions. In this study we have investigated the hydrogen interaction with the Zr m Co n (m+n = 2, 4 and 6) nanoclusters using the state-of-the-art first principles method

  16. CO2 EFFECTS ON MOJAVE DESERT PLANT INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    L. A. DEFALCO; G. C. FERNANDEZ; S. D. SMITH; R. S. NOWAK

    2004-01-01

    Seasonal and interannual droughts characteristic of deserts have the potential to modify plant interactions as atmospheric CO{sub 2} concentrations continue to rise. At the Nevada Desert FACE (free-air CO{sub 2} enrichment) facility in the northern Mojave Desert, the effects of elevated atmospheric C02 (550 vs. ambient {approx}360 {micro}mol mol{sup -1}) on plant interactions were examined during two years of high and low rainfall. Results suggest that CO{sub 2} effects on the interaction between native species and their understory herbs are dependent on the strength of competition when rainfall is plentiful, but are unimportant during annual drought. Seasonal rainfall for 1999 was 23% the long-term average for the area, and neither elevated CO{sub 2} nor the low production of herbaceous neighbors had an effect on relative growth rate (RGR, d{sup -1}) and reproductive effort (RE, number of flowers g{sup -1}) for Achnatherum hymenoides (early season perennial C{sub 3} grass), Pleuraphis rigida (late season perennial C{sub 4} grass), and Larrea tridentata (evergreen C{sub 3} shrub). In contrast, 1998 received 213% the average rainfall. Consequently, the decrease in RGR and increase in RE for Achnatherum, whose period of growth overlaps directly with that of its neighbors, was exaggerated at elevated CO{sub 2}. However, competitive effects of neighbors on Eriogonum trichopes (a winter annual growing in shrub interspaces), Pleuraphis and Larrea were not affected by elevated CO{sub 2}, and possible explanations are discussed. Contrary to expectations, the invasive annual neighbor Bromus madritensis ssp. rubens had little influence on target plant responses because densities in 1998 and 1999 at this site were well below those found in other studies where it has negatively affected perennial plant growth. The extent that elevated CO{sub 2} reduces the performance of Achnatherum in successive years to cause its loss from the plant community depends more on future pressure

  17. Ecology and evolution in microbial systems: the generation and maintenance of diversity in phage-host interactions.

    Science.gov (United States)

    Jessup, Christine M; Forde, Samantha E

    2008-06-01

    Insights gained from studying the interactions between viruses and bacteria have important implications for the ecology and evolution of virus-host interactions in many environments and for pathogen-host and predator-prey interactions in general. Here, we focus on the generation and maintenance of diversity, highlighting recent laboratory and field experiments with microorganisms.

  18. Childhood aggression and the co-occurrence of behavioural and emotional problems: results across ages 3-16 years from multiple raters in six cohorts in the EU-ACTION project.

    Science.gov (United States)

    Bartels, Meike; Hendriks, Anne; Mauri, Matteo; Krapohl, Eva; Whipp, Alyce; Bolhuis, Koen; Conde, Lucia Colodro; Luningham, Justin; Fung Ip, Hill; Hagenbeek, Fiona; Roetman, Peter; Gatej, Raluca; Lamers, Audri; Nivard, Michel; van Dongen, Jenny; Lu, Yi; Middeldorp, Christel; van Beijsterveldt, Toos; Vermeiren, Robert; Hankemeijer, Thomas; Kluft, Cees; Medland, Sarah; Lundström, Sebastian; Rose, Richard; Pulkkinen, Lea; Vuoksimaa, Eero; Korhonen, Tellervo; Martin, Nicholas G; Lubke, Gitta; Finkenauer, Catrin; Fanos, Vassilios; Tiemeier, Henning; Lichtenstein, Paul; Plomin, Robert; Kaprio, Jaakko; Boomsma, Dorret I

    2018-05-29

    Childhood aggression and its resulting consequences inflict a huge burden on affected children, their relatives, teachers, peers and society as a whole. Aggression during childhood rarely occurs in isolation and is correlated with other symptoms of childhood psychopathology. In this paper, we aim to describe and improve the understanding of the co-occurrence of aggression with other forms of childhood psychopathology. We focus on the co-occurrence of aggression and other childhood behavioural and emotional problems, including other externalising problems, attention problems and anxiety-depression. The data were brought together within the EU-ACTION (Aggression in Children: unravelling gene-environment interplay to inform Treatment and InterventiON strategies) project. We analysed the co-occurrence of aggression and other childhood behavioural and emotional problems as a function of the child's age (ages 3 through 16 years), gender, the person rating the behaviour (father, mother or self) and assessment instrument. The data came from six large population-based European cohort studies from the Netherlands (2x), the UK, Finland and Sweden (2x). Multiple assessment instruments, including the Child Behaviour Checklist (CBCL), the Strengths and Difficulties Questionnaire (SDQ) and Multidimensional Peer Nomination Inventory (MPNI), were used. There was a good representation of boys and girls in each age category, with data for 30,523 3- to 4-year-olds (49.5% boys), 20,958 5- to 6-year-olds (49.6% boys), 18,291 7- to 8-year-olds (49.0% boys), 27,218 9- to 10-year-olds (49.4% boys), 18,543 12- to 13-year-olds (48.9% boys) and 10,088 15- to 16-year-olds (46.6% boys). We replicated the well-established gender differences in average aggression scores at most ages for parental ratings. The gender differences decreased with age and were not present for self-reports. Aggression co-occurred with the majority of other behavioural and social problems, from both externalising and

  19. Interactions between Genetic and Ecological Effects on the Evolution of Life Cycles.

    Science.gov (United States)

    Rescan, Marie; Lenormand, Thomas; Roze, Denis

    2016-01-01

    Sexual reproduction leads to an alternation between haploid and diploid phases, whose relative length varies widely across taxa. Previous genetical models showed that diploid or haploid life cycles may be favored, depending on dominance interactions and on effective recombination rates. By contrast, niche differentiation between haploids and diploids may favor biphasic life cycles, in which development occurs in both phases. In this article, we explore the interplay between genetical and ecological factors, assuming that deleterious mutations affect the competitivity of individuals within their ecological niche and allowing different effects of mutations in haploids and diploids (including antagonistic selection). We show that selection on a modifier gene affecting the relative length of both phases can be decomposed into a direct selection term favoring the phase with the highest mean fitness (due to either ecological differences or differential effects of mutations) and an indirect selection term favoring the phase in which selection is more efficient. When deleterious alleles occur at many loci and in the presence of ecological differentiation between haploids and diploids, evolutionary branching often occurs and leads to the stable coexistence of alleles coding for haploid and diploid cycles, while temporal variations in niche sizes may stabilize biphasic cycles.

  20. Peer substance use associated with the co-occurrence of borderline personality disorder features and drug use problems in college students.

    Science.gov (United States)

    Pizzarello, Scott; Taylor, Jeanette

    2011-01-01

    To determine if the substance use patterns of one's close friends and romantic partners would be a significant contributor to the co-occurrence of borderline personality disorder (BPD) features and drug use problems above and beyond impulsivity and negative emotionality. Participants were 2,202 undergraduates who attended a large southeastern university between 2003 and 2006. All subjects completed measures assessing the presence of BPD symptoms, drug use problems, general personality traits, and the proportion of their friends and partners who had used illicit drugs within the past 12 months. The illicit drug use patterns of one's friends and romantic partners was a significant contributor to the co-occurrence of BPD features and drug use problems even when controlling for levels of impulsivity and negative emotionality. These findings suggest possible additional avenues for treatment focusing on helping students with BPD and drug use problems modify their social group.

  1. The possibility of coexistence and co-development in language competition: ecology-society computational model and simulation.

    Science.gov (United States)

    Yun, Jian; Shang, Song-Chao; Wei, Xiao-Dan; Liu, Shuang; Li, Zhi-Jie

    2016-01-01

    Language is characterized by both ecological properties and social properties, and competition is the basic form of language evolution. The rise and decline of one language is a result of competition between languages. Moreover, this rise and decline directly influences the diversity of human culture. Mathematics and computer modeling for language competition has been a popular topic in the fields of linguistics, mathematics, computer science, ecology, and other disciplines. Currently, there are several problems in the research on language competition modeling. First, comprehensive mathematical analysis is absent in most studies of language competition models. Next, most language competition models are based on the assumption that one language in the model is stronger than the other. These studies tend to ignore cases where there is a balance of power in the competition. The competition between two well-matched languages is more practical, because it can facilitate the co-development of two languages. A third issue with current studies is that many studies have an evolution result where the weaker language inevitably goes extinct. From the integrated point of view of ecology and sociology, this paper improves the Lotka-Volterra model and basic reaction-diffusion model to propose an "ecology-society" computational model for describing language competition. Furthermore, a strict and comprehensive mathematical analysis was made for the stability of the equilibria. Two languages in competition may be either well-matched or greatly different in strength, which was reflected in the experimental design. The results revealed that language coexistence, and even co-development, are likely to occur during language competition.

  2. Formal Models of the Network Co-occurrence Underlying Mental Operations.

    Directory of Open Access Journals (Sweden)

    Danilo Bzdok

    2016-06-01

    Full Text Available Systems neuroscience has identified a set of canonical large-scale networks in humans. These have predominantly been characterized by resting-state analyses of the task-unconstrained, mind-wandering brain. Their explicit relationship to defined task performance is largely unknown and remains challenging. The present work contributes a multivariate statistical learning approach that can extract the major brain networks and quantify their configuration during various psychological tasks. The method is validated in two extensive datasets (n = 500 and n = 81 by model-based generation of synthetic activity maps from recombination of shared network topographies. To study a use case, we formally revisited the poorly understood difference between neural activity underlying idling versus goal-directed behavior. We demonstrate that task-specific neural activity patterns can be explained by plausible combinations of resting-state networks. The possibility of decomposing a mental task into the relative contributions of major brain networks, the "network co-occurrence architecture" of a given task, opens an alternative access to the neural substrates of human cognition.

  3. Material microstructures analyzed by using gray level Co-occurrence matrices

    International Nuclear Information System (INIS)

    Hu Yansu; Wang Zhijun; Fan Xiaoguang; Li Junjie; Gao Ang

    2017-01-01

    The mechanical properties of materials greatly depend on the microstructure morphology. The quantitative characterization of material microstructures is essential for the performance prediction and hence the material design. At present, the quantitative characterization methods mainly rely on the microstructure characterization of shape, size, distribution, and volume fraction, which related to the mechanical properties. These traditional methods have been applied for several decades and the subjectivity of human factors induces unavoidable errors. In this paper, we try to bypass the traditional operations and identify the relationship between the microstructures and the material properties by the texture of image itself directly. The statistical approach is based on gray level Co-occurrence matrix (GLCM), allowing an objective and repeatable study on material microstructures. We first present how to identify GLCM with the optimal parameters, and then apply the method on three systems with different microstructures. The results show that GLCM can reveal the interface information and microstructures complexity with less human impact. Naturally, there is a good correlation between GLCM and the mechanical properties. (paper)

  4. The repository ecology: an approach to understanding repository and service interactions

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    An increasing number of university institutions and other organisations are deciding to deploy repositories and a growing number of formal and informal distributed services are supporting or capitalising on the information these repositories provide. Despite reasonably well understood technical architectures, early majority adopters may struggle to articulate their place within the actualities of a wider information environment. The idea of a repository ecology provides developers and administrators with a useful way of articulating and analysing their place in the information environment, and the technical and organisational interactions they have, or are developing, with other parts of such an environment. This presentation will provide an overview of the concept of a repository ecology and examine some examples from the domains of scholarly communications and elearning. View John Robertson's biography

  5. The relationship between landscape patterns and human-caused fire occurrence in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Castafreda-Aumedes, S.; Garcia-Martin, A.; Vega-Garcia, C.

    2013-05-01

    Aim of study: Human settlements and activities have completely modified landscape structure in the Mediterranean region. Vegetation patterns show the interactions between human activities and natural processes on the territory, and allow understanding historical ecological processes and socioeconomic factors. The arrangement of land uses in the rural landscape can be perceived as a proxy for human activities that often lead to the use, and escape, of fire, the most important disturbance in our forest landscapes. In this context, we tried to predict human-caused fire occurrence in a 5-year period by quantifying landscape patterns. Area of study: This study analyses the Spanish territory included in the Iberian Peninsula and Balearic Islands (497,166 km{sup 2}). Material and Methods: We evaluated spatial pattern applying a set of commonly used landscape ecology metrics to landscape windows of 10x10 sq km (4751 units in the UTM grid) overlaid on the Forest Map of Spain, MFE200. Main results: The best logistic regression model obtained included Shannon's Diversity Index, Mean Patch Edge and Mean Shape Index as explicative variables and the global percentage of correct predictions was 66.3 %. Research highlights: Our results suggested that the highest probability of fire occurrence at that time was associated with areas with a greater diversity of land uses and with more compact patches with fewer edges. (Author) 58 refs.

  6. Magnetostatic Interaction in Fe-Co Nanowires

    Directory of Open Access Journals (Sweden)

    Laura Elbaile

    2012-01-01

    Full Text Available Arrays of Fe-Co alloy nanowires with diameter around 35 nm and several micrometers in length have been synthesized by codepositing Fe and Co into porous anodic alumina. The morphology, structure, and magnetic properties of the nanowires (hysteresis loops and remanence curves were characterized by SEM, TEM, X-ray diffraction (XRD, and VSM, respectively. The XRD patterns indicate that the Fe-Co nanowires present a body-centered cubic (bcc structure and a preferred (110 orientation perpendicular to the template surface. From the hysteresis loops obtained with the magnetic field applied in the axis direction of the nanowires, we can observe that the coercive field slightly decreases when the nanowire length increases. This magnetic behaviour is analyzed considering the shape anisotropy and the dipolar interactions among nanowires.

  7. A 'Knowledge Ecologies' Analysis of Co-designing Water and Sanitation Services in Alaska.

    Science.gov (United States)

    Fam, Dena; Sofoulis, Zoë

    2017-08-01

    Willingness to collaborate across disciplinary boundaries is necessary but not sufficient for project success. This is a case study of a transdisciplinary project whose success was constrained by contextual factors that ultimately favoured technical and scientific forms of knowledge over the cultural intelligence that might ensure technical solutions were socially feasible. In response to Alaskan Water and Sewer Challenge (AWSC), an international team with expertise in engineering, consultative design and public health formed in 2013 to collaborate on a two-year project to design remote area water and sanitation systems in consultation with two native Alaskan communities. Team members were later interviewed about their experiences. Project processes are discussed using a 'Knowledge Ecology' framework, which applies principles of ecosystems analysis to knowledge ecologies, identifying the knowledge equivalents of 'biotic' and 'abiotic' factors and looking at their various interactions. In a positivist 'knowledge integration' perspective, different knowledges are like Lego blocks that combine with other 'data sets' to create a unified structure. The knowledge ecology framework highlights how interactions between different knowledges and knowledge practitioners ('biotic factors') are shaped by contextual ('abiotic') factors: the conditions of knowledge production, the research policy and funding climate, the distribution of research resources, and differential access to enabling infrastructures (networks, facilities). This case study highlights the importance of efforts to negotiate between different knowledge frameworks, including by strategic use of language and precepts that help translate social research into technical design outcomes that are grounded in social reality.

  8. Young Children’s Developmental Ecologies and Kindergarten Readiness

    Science.gov (United States)

    Mollborn, Stefanie

    2016-01-01

    Children enter the crucial transition to school with sociodemographic disparities firmly established. Domain-specific research (e.g., on poverty and family structure) has shed light on these disparities, but we need broader operationalizations of children’s environments to explain them. Building on existing theory, this study articulates the concept of developmental ecology—those interrelated features of a child’s proximal environment that shape development and health. Developmental ecology links structural and demographic factors with interactional, psychological, and genetic factors. Using the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), this study conducts latent class analyses to identify how 41 factors from three domains—namely, household resources, health risks, and ecological changes—cluster within children as four overarching developmental ecologies. Because it documents how numerous factors co-occur within children, this method allows an approximation of their lived environments. Findings illuminate powerful relationships between race/ethnicity, parental age, socioeconomic background, and nativity and a child’s developmental ecology, as well as associations between developmental ecology and kindergarten cognition, behavior, and health. Developmental ecology represents a major pathway through which demographic characteristics shape school readiness. Because specific factors have different implications depending on the ecologies in which they are embedded, findings support the usefulness of a broad ecological approach. PMID:27873222

  9. Children Exposed to Child Maltreatment and Intimate Partner Violence: A Study of Co-Occurrence among Hong Kong Chinese Families

    Science.gov (United States)

    Chan, Ko Ling

    2011-01-01

    Objective: This study assessed the co-occurrence of child maltreatment and intimate partner violence (IPV) and examined the association between them. Method: The cross-sectional study recruited a population-based sample of 1,094 children aged 12-17 years in Hong Kong. Structured questionnaires were used to collect data from the children. The…

  10. Toward a community ecology of landscapes: predicting multiple predator-prey interactions across geographic space.

    Science.gov (United States)

    Schmitz, Oswald J; Miller, Jennifer R B; Trainor, Anne M; Abrahms, Briana

    2017-09-01

    Community ecology was traditionally an integrative science devoted to studying interactions between species and their abiotic environments in order to predict species' geographic distributions and abundances. Yet for philosophical and methodological reasons, it has become divided into two enterprises: one devoted to local experimentation on species interactions to predict community dynamics; the other devoted to statistical analyses of abiotic and biotic information to describe geographic distribution. Our goal here is to instigate thinking about ways to reconnect the two enterprises and thereby return to a tradition to do integrative science. We focus specifically on the community ecology of predators and prey, which is ripe for integration. This is because there is active, simultaneous interest in experimentally resolving the nature and strength of predator-prey interactions as well as explaining patterns across landscapes and seascapes. We begin by describing a conceptual theory rooted in classical analyses of non-spatial food web modules used to predict species interactions. We show how such modules can be extended to consideration of spatial context using the concept of habitat domain. Habitat domain describes the spatial extent of habitat space that predators and prey use while foraging, which differs from home range, the spatial extent used by an animal to meet all of its daily needs. This conceptual theory can be used to predict how different spatial relations of predators and prey could lead to different emergent multiple predator-prey interactions such as whether predator consumptive or non-consumptive effects should dominate, and whether intraguild predation, predator interference or predator complementarity are expected. We then review the literature on studies of large predator-prey interactions that make conclusions about the nature of multiple predator-prey interactions. This analysis reveals that while many studies provide sufficient information

  11. The occurrence and potential ecological risk assessment of bauxite mine-impacted water and sediments in Kuantan, Pahang,Malaysia.

    Science.gov (United States)

    Kusin, Faradiella Mohd; Rahman, Muhammad Syazwan Abd; Madzin, Zafira; Jusop, Shamshuddin; Mohamat-Yusuff, Ferdaus; Ariffin, Mariani; Z, Mohd Syakirin Md

    2017-01-01

    Recent bauxite mining activities in the vicinity of Kuantan, Pahang, have been associated with apparent environmental quality degradation and have raised environmental concerns among the public. This study was carried out to evaluate the overall ecological impacts on water and sediment quality from the bauxite mining activities. Water and sediment samples were collected at seven sampling locations within the bauxite mining areas between June and December 2015. The water samples were analyzed for water quality index (WQI) and distribution of major and trace element geochemistry. Sediment samples were evaluated based on geochemical indices, i.e., the enrichment factor (EF) and geoaccumulation index (I geo ). Potential ecological risk index was estimated to assess the degree to which sediments of the mine-impacted areas have been contaminated with heavy metals. The results showed that WQIs of some locations were classified as slightly polluted and contained metal contents exceeding the recommended guideline values. The EFs indicated minimal to moderate enrichment of metals (Pb, Cu, Zn, Mn, As, Cd, Cr, Ni, Co, and Sr) in the sediments. I geo showed slightly to partially polluted sediments with respect to As at some locations. The potential ecological risk index (RI) showed that As posed the highest potential ecological risk with RI of 52.35-60.92 at two locations, while other locations indicated low risk. The findings from this study have demonstrated the impact of recent bauxite mining activities, which might be of importance to the local communities and relevant authorities to initiate immediate rehabilitation phase of the impacted area.

  12. Digital Ecology: Coexistence and Domination among Interacting Networks

    Science.gov (United States)

    Kleineberg, Kaj-Kolja; Boguñá, Marián

    2015-05-01

    The overwhelming success of Web 2.0, within which online social networks are key actors, has induced a paradigm shift in the nature of human interactions. The user-driven character of Web 2.0 services has allowed researchers to quantify large-scale social patterns for the first time. However, the mechanisms that determine the fate of networks at the system level are still poorly understood. For instance, the simultaneous existence of multiple digital services naturally raises questions concerning which conditions these services can coexist under. Analogously to the case of population dynamics, the digital world forms a complex ecosystem of interacting networks. The fitness of each network depends on its capacity to attract and maintain users’ attention, which constitutes a limited resource. In this paper, we introduce an ecological theory of the digital world which exhibits stable coexistence of several networks as well as the dominance of an individual one, in contrast to the competitive exclusion principle. Interestingly, our theory also predicts that the most probable outcome is the coexistence of a moderate number of services, in agreement with empirical observations.

  13. Enhanced Living by Assessing Voice Pathology Using a Co-Occurrence Matrix.

    Science.gov (United States)

    Muhammad, Ghulam; Alhamid, Mohammed F; Hossain, M Shamim; Almogren, Ahmad S; Vasilakos, Athanasios V

    2017-01-29

    A large number of the population around the world suffers from various disabilities. Disabilities affect not only children but also adults of different professions. Smart technology can assist the disabled population and lead to a comfortable life in an enhanced living environment (ELE). In this paper, we propose an effective voice pathology assessment system that works in a smart home framework. The proposed system takes input from various sensors, and processes the acquired voice signals and electroglottography (EGG) signals. Co-occurrence matrices in different directions and neighborhoods from the spectrograms of these signals were obtained. Several features such as energy, entropy, contrast, and homogeneity from these matrices were calculated and fed into a Gaussian mixture model-based classifier. Experiments were performed with a publicly available database, namely, the Saarbrucken voice database. The results demonstrate the feasibility of the proposed system in light of its high accuracy and speed. The proposed system can be extended to assess other disabilities in an ELE.

  14. Dynamic Assessment of Microbial Ecology (DAME): A web app for interactive analysis and visualization of microbial sequencing data

    Science.gov (United States)

    Dynamic Assessment of Microbial Ecology (DAME) is a shiny-based web application for interactive analysis and visualization of microbial sequencing data. DAME provides researchers not familiar with R programming the ability to access the most current R functions utilized for ecology and gene sequenci...

  15. Value co-creation in service interactions: dimensions and antecedents

    NARCIS (Netherlands)

    Neghina, C.; Caniels, M.; Bloemer, J.M.M.; Birgelen, M.J.H. van

    2013-01-01

    The purpose of this article is to further develop the conceptualization of value co-creation and discuss its dimensions and antecedents. We propose that in service interactions, value co-creation should be understood as a joint collaborative activity between service employees and customers

  16. The co-occurrence of substance use and bullying behaviors among U.S. adolescents: understanding demographic characteristics and social influences.

    Science.gov (United States)

    Luk, Jeremy W; Wang, Jing; Simons-Morton, Bruce G

    2012-10-01

    This study examined the co-occurrence of subtypes of substance use and bullying behaviors using latent class analysis and evaluated latent class differences in demographic characteristics, peer and parental influences. Self-reported questionnaire data were collected from a nationally representative sample (N = 7508) of 6-10th grade adolescents in the United States. Four latent classes were identified: the non-involved (57.7%), substance users (19.4%), bullies (17.5%), and substance-using bullies (5.4%). Older and Hispanic adolescents were more likely to be substance users and substance-using bullies, whereas younger and African American adolescents were more likely to be bullies. Females were more likely to be substance users, whereas males were more likely to be bullies and substance-using bullies. Spending more evenings with peers posed greater risks for substance use, bullying, and the co-occurrence of both problem behaviors. Paternal knowledge exerted protective effects over-and-above the effects of maternal knowledge. Implications for prevention and intervention efforts are discussed. Copyright © 2012 The Foundation for Professionals in Services for Adolescents. All rights reserved.

  17. Visualizing the context of citations referencing papers published by Eugene Garfield: a new type of keyword co-occurrence analysis.

    Science.gov (United States)

    Bornmann, Lutz; Haunschild, Robin; Hug, Sven E

    2018-01-01

    During Eugene Garfield's (EG's) lengthy career as information scientist, he published about 1500 papers. In this study, we use the impressive oeuvre of EG to introduce a new type of bibliometric networks: keyword co-occurrences networks based on the context of citations, which are referenced in a certain paper set (here: the papers published by EG). The citation context is defined by the words which are located around a specific citation. We retrieved the citation context from Microsoft Academic. To interpret and compare the results of the new network type, we generated two further networks: co-occurrence networks which are based on title and abstract keywords from (1) EG's papers and (2) the papers citing EG's publications. The comparison of the three networks suggests that papers of EG and citation contexts of papers citing EG are semantically more closely related to each other than to titles and abstracts of papers citing EG. This result accords with the use of citations in research evaluation that is based on the premise that citations reflect the cognitive influence of the cited on the citing publication.

  18. Interactions among Ecological Factors That Explain the Psychosocial Quality of Life of Children with Complex Needs

    Directory of Open Access Journals (Sweden)

    Sandy Thurston

    2010-01-01

    Full Text Available Purpose. To explore the associations and interactions among ecological factors and explain the psychosocial quality of life of children with complex needs. Methods. In this cross-sectional survey consenting parents were identified by the Children's Treatment Network. Families were eligible if the child from 0 to 19 years, resided in Simcoe/York, and there were multiple family needs. Regression analysis was used to explore associations and interactions. n=429. Results. Younger children, without conduct disorder, without hostile and punitive parenting and with low adverse family impact demonstrated the highest levels of psychosocial quality of life. Statistically significant interactions between processes of care and parent variables highlight the complexity of real life situations. Conclusions. It is not possible to fully understand the child's psychosocial quality of life in complex needs families by considering only simple associations between ecological factors. A multitude of factors and interactions between these factors are simultaneously present and the care of these families requires a holistic approach.

  19. Interspecific interactions in phytophagous insects revisited: a quantitative assessment of competition theory.

    Science.gov (United States)

    Kaplan, Ian; Denno, Robert F

    2007-10-01

    The importance of interspecific competition is a highly controversial and unresolved issue for community ecology in general, and for phytophagous insects in particular. Recent advancements, however, in our understanding of indirect (plant- and enemy-mediated) interactions challenge the historical paradigms of competition. Thus, in the context of this rapidly developing field, we re-evaluate the evidence for interspecific competition in phytophagous insects using a meta-analysis of published studies. Our analysis is specifically designed to test the assumptions underlying traditional competition theory, namely that competitive interactions are symmetrical, necessitate spatial and temporal co-occurrence, and increase in intensity as the density, phylogenetic similarity, and niche overlap of competing species increase. Despite finding frequent evidence for competition, we found very little evidence that plant-feeding insects conform to theoretical predictions for interspecific competition. Interactions were highly asymmetrical, similar in magnitude within vs. between feeding guilds (chewers vs. sap-feeders), and were unaffected by the quantity of resources removed (% defoliation). There was mixed support for the effects of phylogeny, spatial/temporal separation, and the relative strength of intra- vs. interspecific competition. Clearly, a new paradigm that accounts for indirect interactions and facilitation is required to describe how interspecific competition contributes to the organization of phytophagous insect communities, and perhaps to other plant and animal communities as well.

  20. Ionic Liquid Gating Control of RKKY Interaction in FeCoB/Ru/FeCoB and (Pt/Co)2/Ru/(Co/Pt)2 Multilayers.

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qu; Wang, Lei; Zhou, Ziyao; Wang, Liqian; Zhang, Yijun; Zhao, Shishun; Dong, Guohua; Cheng, Yuxin; Min, Tai; Hu, Zhongqiang; Chen, Wei; Xia, Ke; Liu, Ming

    2018-03-07

    To overcome the fundamental challenge of the weak natural response of antiferromagnetic materials under a magnetic field, voltage manipulation of antiferromagnetic interaction is developed to realize ultrafast, high-density, and power efficient antiferromagnetic spintronics. Here, we report a low voltage modulation of Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction via ionic liquid gating in synthetic antiferromagnetic multilayers of FeCoB/Ru/FeCoB and (Pt/Co)2/Ru/(Co/Pt)2. At room temperature, the distinct voltage control of transition between antiferromagnetic and ferromagnetic ordering is realized and up to 80% of perpendicular magnetic moments manage to switch with a small-applied voltage bias of 2.5 V. We related this ionic liquid gating-induced RKKY interaction modification to the disturbance of itinerant electrons inside synthetic antiferromagnetic heterostructure and the corresponding change of its Fermi level. Voltage tuning of RKKY interaction may enable the next generation of switchable spintronics between antiferromagnetic and ferromagnetic modes with both fundamental and practical perspectives.

  1. Peer Substance Use Associated with the Co-Occurrence of Borderline Personality Disorder Features and Drug Use Problems in College Students

    Science.gov (United States)

    Pizzarello, Scott; Taylor, Jeanette

    2011-01-01

    Objective: To determine if the substance use patterns of one's close friends and romantic partners would be a significant contributor to the co-occurrence of borderline personality disorder (BPD) features and drug use problems above and beyond impulsivity and negative emotionality. Participants: Participants were 2,202 undergraduates who attended…

  2. Organisational ecology in the Danish restaurant sector

    DEFF Research Database (Denmark)

    Hjalager, Anne Mette

    2000-01-01

    The article demonstrates the high rates of organisational turmoil in the restaurant sector. The intensity of natural selection depends mainly on the age and size of the enterprise. Affiliation with other enterprises increases the chances of survival, but only if there is a substantial number...... of units co-operating in a group. Surprisingly, the level of staff competence and managerial capacity - measured in quantitative terms - cannot explain the level of success or failure in the restaurant business to any significant degree. Organisational ecology, which constitutes the theoretical...... and methodological base of this article, is a promising research approach to tourism issues. The article, which focuses on explanations for the occurrence of life events in the restaurant sector, calls for more careful policy considerations than are often the case. In particular, human-resource- and labour...

  3. Getting the ecology into interactions between plants and the plant growth-promoting bacterium Pseudomonas fluorescens.

    Science.gov (United States)

    Hol, W H Gera; Bezemer, T Martijn; Biere, Arjen

    2013-01-01

    Plant growth-promoting rhizobacteria (PGPR) are increasingly appreciated for their contributions to primary productivity through promotion of growth and triggering of induced systemic resistance in plants. Here we focus on the beneficial effects of one particular species of PGPR (Pseudomonas fluorescens) on plants through induced plant defense. This model organism has provided much understanding of the underlying molecular mechanisms of PGPR-induced plant defense. However, this knowledge can only be appreciated at full value once we know to what extent these mechanisms also occur under more realistic, species-diverse conditions as are occurring in the plant rhizosphere. To provide the necessary ecological context, we review the literature to compare the effect of P. fluorescens on induced plant defense when it is present as a single species or in combination with other soil dwelling species. Specifically, we discuss combinations with other plant mutualists (bacterial or fungal), plant pathogens (bacterial or fungal), bacterivores (nematode or protozoa), and decomposers. Synergistic interactions between P. fluorescens and other plant mutualists are much more commonly reported than antagonistic interactions. Recent developments have enabled screenings of P. fluorescens genomes for defense traits and this could help with selection of strains with likely positive interactions on biocontrol. However, studies that examine the effects of multiple herbivores, pathogens, or herbivores and pathogens together on the effectiveness of PGPR to induce plant defenses are underrepresented and we are not aware of any study that has examined interactions between P. fluorescens and bacterivores or decomposers. As co-occurring soil organisms can enhance but also reduce the effectiveness of PGPR, a better understanding of the biotic factors modulating P. fluorescens-plant interactions will improve the effectiveness of introducing P. fluorescens to enhance plant production and defense.

  4. 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

  5. Ecosystem management via interacting models of political and ecological processes

    Directory of Open Access Journals (Sweden)

    Haas, T. C.

    2004-01-01

    Full Text Available The decision to implement environmental protection options is a political one. Political realities may cause a country to not heed the most persuasive scientific analysis of an ecosystem's future health. A predictive understanding of the political processes that result in ecosystem management decisions may help guide ecosystem management policymaking. To this end, this article develops a stochastic, temporal model of how political processes influence and are influenced by ecosystem processes. This model is realized in a system of interacting influence diagrams that model the decision making of a country's political bodies. These decisions interact with a model of the ecosystem enclosed by the country. As an example, a model for Cheetah (Acinonyx jubatus management in Kenya is constructed and fitted to decision and ecological data.

  6. Time is honey: circadian clocks of bees and flowers and how their interactions may influence ecological communities.

    Science.gov (United States)

    Bloch, Guy; Bar-Shai, Noam; Cytter, Yotam; Green, Rachel

    2017-11-19

    The interactions between flowering plants and insect pollinators shape ecological communities and provide one of the best examples of coevolution. Although these interactions have received much attention in both ecology and evolution, their temporal aspects are little explored. Here we review studies on the circadian organization of pollination-related traits in bees and flowers. Research, mostly with the honeybee, Apis mellifera , has implicated the circadian clock in key aspects of their foraging for flower rewards. These include anticipation, timing of visits to flowers at specified locations and time-compensated sun-compass orientation. Floral rhythms in traits such as petal opening, scent release and reward availability also show robust daily rhythms. However, in only few studies was it possible to adequately determine whether these oscillations are driven by external time givers such as light and temperature cycles, or endogenous circadian clocks. The interplay between the timing of flower and pollinator rhythms may be ecologically significant. Circadian regulation of pollination-related traits in only few species may influence the entire pollination network and thus affect community structure and local biodiversity. We speculate that these intricate chronobiological interactions may be vulnerable to anthropogenic effects such as the introduction of alien invasive species, pesticides or environmental pollutants.This article is part of the themed issue 'Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals'. © 2017 The Author(s).

  7. Parallel ecological networks in ecosystems

    Science.gov (United States)

    Olff, Han; Alonso, David; Berg, Matty P.; Eriksson, B. Klemens; Loreau, Michel; Piersma, Theunis; Rooney, Neil

    2009-01-01

    In ecosystems, species interact with other species directly and through abiotic factors in multiple ways, often forming complex networks of various types of ecological interaction. Out of this suite of interactions, predator–prey interactions have received most attention. The resulting food webs, however, will always operate simultaneously with networks based on other types of ecological interaction, such as through the activities of ecosystem engineers or mutualistic interactions. Little is known about how to classify, organize and quantify these other ecological networks and their mutual interplay. The aim of this paper is to provide new and testable ideas on how to understand and model ecosystems in which many different types of ecological interaction operate simultaneously. We approach this problem by first identifying six main types of interaction that operate within ecosystems, of which food web interactions are one. Then, we propose that food webs are structured among two main axes of organization: a vertical (classic) axis representing trophic position and a new horizontal ‘ecological stoichiometry’ axis representing decreasing palatability of plant parts and detritus for herbivores and detrivores and slower turnover times. The usefulness of these new ideas is then explored with three very different ecosystems as test cases: temperate intertidal mudflats; temperate short grass prairie; and tropical savannah. PMID:19451126

  8. The co-creation of meaningful action: bridging enaction and interactional sociology.

    Science.gov (United States)

    De Jaegher, Hanne; Peräkylä, Anssi; Stevanovic, Melisa

    2016-05-05

    What makes possible the co-creation of meaningful action? In this paper, we go in search of an answer to this question by combining insights from interactional sociology and enaction. Both research schools investigate social interactions as such, and conceptualize their organization in terms of autonomy. We ask what it could mean for an interaction to be autonomous, and discuss the structures and processes that contribute to and are maintained in the so-called interaction order. We also discuss the role played by individual vulnerability as well as the vulnerability of social interaction processes in the co-creation of meaningful action. Finally, we outline some implications of this interdisciplinary fraternization for the empirical study of social understanding, in particular in social neuroscience and psychology, pointing out the need for studies based on dynamic systems approaches on origins and references of coordination, and experimental designs to help understand human co-presence. © 2016 The Authors.

  9. The co-creation of meaningful action: bridging enaction and interactional sociology

    Science.gov (United States)

    Peräkylä, Anssi; Stevanovic, Melisa

    2016-01-01

    What makes possible the co-creation of meaningful action? In this paper, we go in search of an answer to this question by combining insights from interactional sociology and enaction. Both research schools investigate social interactions as such, and conceptualize their organization in terms of autonomy. We ask what it could mean for an interaction to be autonomous, and discuss the structures and processes that contribute to and are maintained in the so-called interaction order. We also discuss the role played by individual vulnerability as well as the vulnerability of social interaction processes in the co-creation of meaningful action. Finally, we outline some implications of this interdisciplinary fraternization for the empirical study of social understanding, in particular in social neuroscience and psychology, pointing out the need for studies based on dynamic systems approaches on origins and references of coordination, and experimental designs to help understand human co-presence. PMID:27069055

  10. The geographical co-distribution and socio-ecological drivers of childhood pneumonia and diarrhoea in Queensland, Australia.

    Science.gov (United States)

    Xu, Z; Hu, W; Tong, S

    2015-04-01

    SUMMARY This study aimed to explore the spatio-temporal patterns, geographical co-distribution, and socio-ecological drivers of childhood pneumonia and diarrhoea in Queensland. A Bayesian conditional autoregressive model was used to quantify the impacts of socio-ecological factors on both childhood pneumonia and diarrhoea at a postal area level. A distinct seasonality of childhood pneumonia and diarrhoea was found. Childhood pneumonia and diarrhoea were mainly distributed in the northwest of Queensland. Mount Isa city was the high-risk cluster where childhood pneumonia and diarrhoea co-distributed. Emergency department visits (EDVs) for pneumonia increased by 3% per 10-mm increase in monthly average rainfall in wet seasons. By comparison, a 10-mm increase in monthly average rainfall may cause an increase of 4% in EDVs for diarrhoea. Monthly average temperature was negatively associated with EDVs for childhood diarrhoea in wet seasons. Low socioeconomic index for areas (SEIFA) was associated with high EDVs for childhood pneumonia. Future pneumonia and diarrhoea prevention and control measures in Queensland should focus more on Mount Isa.

  11. Differences in life-history and ecological traits between co-occurring Panulirus spiny lobsters (Decapoda, Palinuridae).

    Science.gov (United States)

    Briones-Fourzán, Patricia

    2014-01-01

    Coexistence of closely related species may be promoted by niche differentiation or result from interspecific trade-offs in life history and ecological traits that influence relative fitness differences and contribute to competitive inequalities. Although insufficient to prove coexistence, trait comparisons provide a first step to identify functional differences between co-occurring congeneric species in relation to mechanisms of coexistence. Here, a comparative review on life history and ecological traits is presented for two pairs of co-occurring species of spiny lobsters in the genus Panulirus: Panulirusgracilis and Panulirusinflatus from the Eastern Central Pacific region, and Panulirusargus and Panulirusguttatus from the Caribbean region. Panulirusgracilis and Panulirusinflatus have similar larval, postlarval, and adult sizes and a similar diet, but differ in degree of habitat specialization, fecundity, and growth rate. However, little is known on behavioral traits of these two species that may influence their competitive abilities and susceptibility to predators. The more abundant information on Panulirusargus and Panulirusguttatus shows that these two species differ more broadly in degree of habitat specialization, larval, postlarval and adult sizes, diet, fecundity, growth rate, degree of sociality, defense mechanisms, susceptibility to predators, and chemical ecology, suggesting a greater degree of niche differentiation between Panulirusargus and Panulirusguttatus than between Panulirusgracilis and Panulirusinflatus. Whether the substantial niche differentiation and apparent interspecific trade-offs between Panulirusargus and Panulirusguttatus relative to Panulirusgracilis and Panulirusinflatus reflect an earlier divergence of the former pair of species in the evolution of the genus constitutes an intriguing hypothesis. However, whether or not post-divergence evolution of each species pair occurred in sympatry remains uncertain.

  12. Phylogenetic Structure of Plant Communities: Are Polyploids Distantly Related to Co-occurring Diploids?

    Directory of Open Access Journals (Sweden)

    Michelle L. Gaynor

    2018-04-01

    Full Text Available Polyploidy is widely acknowledged to have played an important role in the evolution and diversification of vascular plants. However, the influence of genome duplication on population-level dynamics and its cascading effects at the community level remain unclear. In part, this is due to persistent uncertainties over the extent of polyploid phenotypic variation, and the interactions between polyploids and co-occurring species, and highlights the need to integrate polyploid research at the population and community level. Here, we investigate how community-level patterns of phylogenetic relatedness might influence escape from minority cytotype exclusion, a classic population genetics hypothesis about polyploid establishment, and population-level species interactions. Focusing on two plant families in which polyploidy has evolved multiple times, Brassicaceae and Rosaceae, we build upon the hypothesis that the greater allelic and phenotypic diversity of polyploids allow them to successfully inhabit a different geographic range compared to their diploid progenitor and close relatives. Using a phylogenetic framework, we specifically test (1 whether polyploid species are more distantly related to diploids within the same community than co-occurring diploids are to one another, and (2 if polyploid species tend to exhibit greater ecological success than diploids, using species abundance in communities as an indicator of successful establishment. Overall, our results suggest that the effects of genome duplication on community structure are not clear-cut. We find that polyploid species tend to be more distantly related to co-occurring diploids than diploids are to each other. However, we do not find a consistent pattern of polyploid species being more abundant than diploid species, suggesting polyploids are not uniformly more ecologically successful than diploids. While polyploidy appears to have some important influences on species co-occurrence in

  13. Network structure beyond food webs: mapping non-trophic and trophic interactions on Chilean rocky shores.

    Science.gov (United States)

    Sonia Kéfi; Berlow, Eric L; Wieters, Evie A; Joppa, Lucas N; Wood, Spencer A; Brose, Ulrich; Navarrete, Sergio A

    2015-01-01

    How multiple types of non-trophic interactions map onto trophic networks in real communities remains largely unknown. We present the first effort, to our knowledge, describing a comprehensive ecological network that includes all known trophic and diverse non-trophic links among >100 coexisting species for the marine rocky intertidal community of the central Chilean coast. Our results suggest that non-trophic interactions exhibit highly nonrandom structures both alone and with respect to food web structure. The occurrence of different types of interactions, relative to all possible links, was well predicted by trophic structure and simple traits of the source and target species. In this community, competition for space and positive interactions related to habitat/refuge provisioning by sessile and/or basal species were by far the most abundant non-trophic interactions. If these patterns are orroborated in other ecosystems, they may suggest potentially important dynamic constraints on the combined architecture of trophic and non-trophic interactions. The nonrandom patterning of non-trophic interactions suggests a path forward for developing a more comprehensive ecological network theory to predict the functioning and resilience of ecological communities.

  14. Hybridization Associated with Cycles of Ecological Succession in a Passerine Bird.

    Science.gov (United States)

    Duckworth, Renée A; Semenov, Georgy A

    2017-10-01

    Identifying the diversity of contexts that can lead to hybridization is important for understanding its prevalence and dynamics in natural populations. Despite the potential of ecological succession to dramatically alter species co-occurrence and abundances, it is unknown whether it directly promotes hybridization and, if so, has long-lasting consequences. Here, we summarize 30 years of survey data across 10 populations to show that in western and mountain bluebirds, heterospecific pairing occurs during repeatable and transient colonization events at the early stages of species turnover. Despite mixed pairing occurring only during early succession, genetic data showed presence of hybrids at both early and late successional stages. Moreover, hybrids showed novel patterns of variation in morphology and behavior, emphasizing that even ephemeral contexts for hybridization can have important evolutionary consequences. Our results suggest that because ecological succession often brings together closely related competitors in disparate numbers but lasts for only a brief period of time, it may be a widespread but underappreciated context for hybridization.

  15. Interactive effect of temperature and CO2 increase in Arctic phytoplankton

    Directory of Open Access Journals (Sweden)

    Alexandra eCoello-Camba

    2014-10-01

    Full Text Available An experiment was performed in order to analyze the effects of the increase in water temperature and CO2 partial pressure expected for the end of this century in a present phytoplankton community inhabiting the Arctic Ocean. We analyzed both factors acting independently and together, to test possible interactions between them. The arctic planktonic community was incubated under 6 different treatments combining three experimental temperatures (1 ºC, 6 ºC and 10 ºC with two different CO2 levels of 380 ppm or 1000 ppm, at the UNIS installations in Longyearbyen (Svalbard, in summer 2010. Under warmer temperatures, a decrease in chlorophyll a concentration, biovolume and primary production was found, together with a shift in community structure towards a dominance of smaller cells (nano-sized. Effects of increased pCO2 were more modest, and although interactions were weak, our results suggest antagonistic interactive effects amongst increased temperature and CO2 levels, as elevated CO2 compensated partially the decrease in phytoplankton biomass induced by temperature in some groups. Interactions between the two stressors were generally weak, but elevated CO2 was observed to lead to a stepper decline in primary production with warming. Our results also suggest that future increases in water temperature and pCO2 would lead to a decrease in the community chl a concentration and biomass in the Arctic phytoplankton communities examined, leading to communities dominated by smaller nano-phytoplankton groups, with important consequences for the flow of carbon and food web dynamics.

  16. Ecological interactions affecting population-level responses to chemical stress in Mesocyclops leuckarti.

    Science.gov (United States)

    Kulkarni, Devdutt; Hommen, Udo; Schäffer, Andreas; Preuss, Thomas G

    2014-10-01

    Higher tiers of ecological risk assessment (ERA) consider population and community-level endpoints. At the population level, the phenomenon of density dependence is one of the most important ecological processes that influence population dynamics. In this study, we investigated how different mechanisms of density dependence would influence population-level ERA of the cyclopoid copepod Mesocyclops leuckarti under toxicant exposure. We used a combined approach of laboratory experiments and individual-based modelling. An individual-based model was developed for M. leuckarti to simulate population dynamics under triphenyltin exposure based on individual-level ecological and toxicological data from laboratory experiments. The study primarily aimed to-(1) determine which life-cycle processes, based on feeding strategies, are most significant in determining density dependence (2) explore how these mechanisms of density dependence affect extrapolation from individual-level effects to the population level under toxicant exposure. Model simulations showed that cannibalism of nauplii that were already stressed by TPT exposure contributed to synergistic effects of biotic and abiotic factors and led to a twofold stress being exerted on the nauplii, thereby resulting in a higher population vulnerability compared to the scenario without cannibalism. Our results suggest that in population-level risk assessment, it is easy to underestimate toxicity unless underlying ecological interactions including mechanisms of population-level density regulation are considered. This study is an example of how a combined approach of experiments and mechanistic modelling can lead to a thorough understanding of ecological processes in ecotoxicology and enable a more realistic ERA. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Sensitivity of the green alga Pediastrum duplex Meyen to allelochemicals is strain-specific and not related to co-occurrence with allelopathic macrophytes.

    Directory of Open Access Journals (Sweden)

    Falk Eigemann

    Full Text Available Interspecific differences in the response of microalgae to stress have numerous ecological implications. However, little is known of intraspecific sensitivities and the potential role of local genetic adaptation of populations. We compared the allelochemical sensitivity of 23 Pediastrum duplex Meyen strains, a common component of the freshwater phytoplankton. In order to test for local genetic adaptation, strains were isolated from water bodies with and without the allelopathically-active submerged macrophyte Myriophyllum. Strains were assigned to P. duplex on the basis of cell shape and colony morphology and only P. duplex strains that belonged to the same lineage in an ITS rDNA phylogeny were used. Inhibition of strain growth rates and maximum quantum yields of photosystem II were measured after exposure to tannic acid (TA and co-culture with Myriophyllum spicatum. Growth rate inhibition varied over one order of magnitude between the P. duplex strains. There was no correlation between the presence of Myriophyllum in the source location and the sensitivity of the strains to TA or the presence of Myriophyllum, suggesting that at least strong unidirectional local adaptation to Myriophyllum had not taken place in the studied water bodies. The maximum quantum yield of photosystem II of TA exposed algae decreased, whereas the yield of algae exposed to M. spicatum was slightly higher than that of the controls. The ranking of P. duplex strain sensitivities differed between the types of exposure (single additions of TA versus co-existence with M. spicatum and the parameter measured (growth rate versus maximum quantum yield, emphasizing the importance of measuring multiple traits when analysing strain-specific sensitivities towards allelochemicals. The observation that sensitivities to allelochemicals vary widely among strains of a single freshwater algal species should be taken into account if evaluating ecological consequences of allelopathic

  18. Restoring fish ecological quality in estuaries: Implication of interactive and cumulative effects among anthropogenic stressors.

    Science.gov (United States)

    Teichert, Nils; Borja, Angel; Chust, Guillem; Uriarte, Ainhize; Lepage, Mario

    2016-01-15

    Estuaries are subjected to multiple anthropogenic stressors, which have additive, antagonistic or synergistic effects. Current challenges include the use of large databases of biological monitoring surveys (e.g. the European Water Framework Directive) to help environmental managers prioritizing restoration measures. This study investigated the impact of nine stressor categories on the fish ecological status derived from 90 estuaries of the North East Atlantic countries. We used a random forest model to: 1) detect the dominant stressors and their non-linear effects; 2) evaluate the ecological benefits expected from reducing pressure from stressors; and 3) investigate the interactions among stressors. Results showed that largest restoration benefits were expected when mitigating water pollution and oxygen depletion. Non-additive effects represented half of pairwise interactions among stressors, and antagonisms were the most common. Dredged sediments, flow changes and oxygen depletion were predominantly implicated in non-additive interactions, whereas the remainder stressors often showed additive impacts. The prevalence of interactive impacts reflects a complex scenario for estuaries management; hence, we proposed a step-by-step restoration scheme focusing on the mitigation of stressors providing the maximum of restoration benefits under a multi-stress context. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. The logic of ecological patchiness.

    Science.gov (United States)

    Grünbaum, Daniel

    2012-04-06

    Most ecological interactions occur in environments that are spatially and temporally heterogeneous-'patchy'-across a wide range of scales. In contrast, most theoretical models of ecological interactions, especially large-scale models applied to societal issues such as climate change, resource management and human health, are based on 'mean field' approaches in which the underlying patchiness of interacting consumers and resources is intentionally averaged out. Mean field ecological models typically have the advantages of tractability, few parameters and clear interpretation; more technically complex spatially explicit models, which resolve ecological patchiness at some (or all relevant) scales, generally lack these advantages. This report presents a heuristic analysis that incorporates important elements of consumer-resource patchiness with minimal technical complexity. The analysis uses scaling arguments to establish conditions under which key mechanisms-movement, reproduction and consumption-strongly affect consumer-resource interactions in patchy environments. By very general arguments, the relative magnitudes of these three mechanisms are quantified by three non-dimensional ecological indices: the Frost, Strathmann and Lessard numbers. Qualitative analysis based on these ecological indices provides a basis for conjectures concerning the expected characteristics of organisms, species interactions and ecosystems in patchy environments.

  20. A Single-Granule-Level Approach Reveals Ecological Heterogeneity in an Upflow Anaerobic Sludge Blanket Reactor.

    Directory of Open Access Journals (Sweden)

    Kyohei Kuroda

    Full Text Available Upflow anaerobic sludge blanket (UASB reactor has served as an effective process to treat industrial wastewater such as purified terephthalic acid (PTA wastewater. For optimal UASB performance, balanced ecological interactions between syntrophs, methanogens, and fermenters are critical. However, much of the interactions remain unclear because UASB have been studied at a "macro"-level perspective of the reactor ecosystem. In reality, such reactors are composed of a suite of granules, each forming individual micro-ecosystems treating wastewater. Thus, typical approaches may be oversimplifying the complexity of the microbial ecology and granular development. To identify critical microbial interactions at both macro- and micro- level ecosystem ecology, we perform community and network analyses on 300 PTA-degrading granules from a lab-scale UASB reactor and two full-scale reactors. Based on MiSeq-based 16S rRNA gene sequencing of individual granules, different granule-types co-exist in both full-scale reactors regardless of granule size and reactor sampling depth, suggesting that distinct microbial interactions occur in different granules throughout the reactor. In addition, we identify novel networks of syntrophic metabolic interactions in different granules, perhaps caused by distinct thermodynamic conditions. Moreover, unseen methanogenic relationships (e.g. "Candidatus Aminicenantes" and Methanosaeta are observed in UASB reactors. In total, we discover unexpected microbial interactions in granular micro-ecosystems supporting UASB ecology and treatment through a unique single-granule level approach.

  1. A Single-Granule-Level Approach Reveals Ecological Heterogeneity in an Upflow Anaerobic Sludge Blanket Reactor

    Science.gov (United States)

    Mei, Ran; Narihiro, Takashi; Bocher, Benjamin T. W.; Yamaguchi, Takashi; Liu, Wen-Tso

    2016-01-01

    Upflow anaerobic sludge blanket (UASB) reactor has served as an effective process to treat industrial wastewater such as purified terephthalic acid (PTA) wastewater. For optimal UASB performance, balanced ecological interactions between syntrophs, methanogens, and fermenters are critical. However, much of the interactions remain unclear because UASB have been studied at a “macro”-level perspective of the reactor ecosystem. In reality, such reactors are composed of a suite of granules, each forming individual micro-ecosystems treating wastewater. Thus, typical approaches may be oversimplifying the complexity of the microbial ecology and granular development. To identify critical microbial interactions at both macro- and micro- level ecosystem ecology, we perform community and network analyses on 300 PTA–degrading granules from a lab-scale UASB reactor and two full-scale reactors. Based on MiSeq-based 16S rRNA gene sequencing of individual granules, different granule-types co-exist in both full-scale reactors regardless of granule size and reactor sampling depth, suggesting that distinct microbial interactions occur in different granules throughout the reactor. In addition, we identify novel networks of syntrophic metabolic interactions in different granules, perhaps caused by distinct thermodynamic conditions. Moreover, unseen methanogenic relationships (e.g. “Candidatus Aminicenantes” and Methanosaeta) are observed in UASB reactors. In total, we discover unexpected microbial interactions in granular micro-ecosystems supporting UASB ecology and treatment through a unique single-granule level approach. PMID:27936088

  2. Sensation seeking indirectly affects perceptions of risk for co-occurrent substance use.

    Science.gov (United States)

    Hittner, James B; Warner, Margaret A; Swickert, Rhonda J

    2016-02-01

    High sensation seekers engage in more frequent substance use and perceive a host of potentially dangerous activities as less risky than do low sensation seekers. However, despite a plethora of research on these topics, no study has examined the extent to which personal substance use mediates the association between sensation seeking and perceived risk of substance use. To address this question, we recruited a sample of 79 young adults (mean age=19.1 years, standard deviation=1.4). Participants completed questionnaire measures of sensation seeking, substance use, and perceived risk of co-occurrent substance use. Results from path-analytic modeling indicated that both alcohol use and marijuana use mediated the influence of sensation seeking on perceptions of risk for moderately risky, but not highly risky, pairs of substances. Strengths and limitations of the present study were discussed and directions for future research were suggested.

  3. The potential effect of high atmospheric CO2 on soil fungi-invertebrate interactions

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Nováková, Alena; Jones, H.

    2002-01-01

    Roč. 8, - (2002), s. 339-344 ISSN 1354-1013 R&D Projects: GA AV ČR IAB6066903 Institutional research plan: CEZ:AV0Z6066911 Keywords : food web * global changes * high CO2 Subject RIV: EH - Ecology, Behaviour Impact factor: 3.398, year: 2002

  4. Co-occurrence of substance use related and mental health problems in the Finnish social and health care system.

    Science.gov (United States)

    Kuussaari, Kristiina; Hirschovits-Gerz, Tanja

    2016-03-01

    Many studies have noted that substance abuse and mental health problems often occur simultaneously. The aim of the work reported here was to study the co-occurrence of mental health problems and problems related to substance use in a sample of clients visiting the Finnish social and health care services for issues related to substance use. We collected background information on the clients and considered the parts of the treatment system in which these clients were treated. Survey data on intoxicant-related cases in the Finnish health care and social services were gathered on a single day in 2011. During the 24 hours of data collection, all intoxicant-related cases were reported and data were obtained for 11,738 intoxicant-related cases. In this analysis we took into account the clients' background variables, mental health variables, information on the treatment type and the main reasons for the client being in treatment. The χ(2) test, Fisher's exact test and binary logistic regression analysis were used. Half of the visiting clients had both substance use related and mental health problems. The strongest factors associated with the co-occurrence of substance use related and mental health problems were female sex, younger age and single marital status. Clients with co-occurring problems were more often treated in the health care services, whereas clients with only substance use related problems were primarily treated in specialized services for the treatment of substance abuse. It is important to identify clients with co-occurring substance use related and mental health problems. In this study, half of the clients presenting to the Finnish social and health care treatment system had both these problems. © 2015 the Nordic Societies of Public Health.

  5. Using interactive model simulations in co-design : An experiment in urban design

    NARCIS (Netherlands)

    Steen, M.G.D.; Arendsen, J.; Cremers, A.H.M.; Vries, A. de; Jong, J.M.G. de; Koning, N.M. de

    2013-01-01

    This paper presents an experiment in which people performed a co-design task in urban design, using a multi-user touch table application with or without interactive model simulations. We hypothesised that using the interactive model simulations would improve communication and co-operation between

  6. Towards an Ecological Inquiry in Child-Computer Interaction

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Iversen, Ole Sejer; Hjermitslev, Thomas

    2013-01-01

    The paper introduces an Ecological Inquiry as a methodological approach for designing technology with children. The inquiry is based on the ‘ecological turn’ in HCI, Ubiquitous Computing and Participatory Design that shift the emphasis of design from technological artifacts to entire use ecologies...... into which technologies are integrated. Our Ecological Inquiry extends Cooperative Inquiry in three directions: from understanding to emergence of social practices and meanings, from design of artifacts to hybrid environments, and from a focus on technology to appropriations through design and use. We...... exemplify our approach in a case study in which we designed social technologies for hybrid learning environments with children in two schools, and discuss how an Ecological Inquiry can inform existing approaches in CCI....

  7. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D; Ahmad, Aamina; Hunter, Mark D; de Roode, Jacobus C

    2015-10-22

    Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host-parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host-parasite systems. © 2015 The Author(s).

  8. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host–parasite interactions

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D.; Ahmad, Aamina; Hunter, Mark D.; de Roode, Jacobus C.

    2015-01-01

    Host–parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host–parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host–parasite systems. PMID:26468247

  9. Geographic variation and socio-demographic determinants of the co-occurrence of risky health behaviours in 27 European Union member states.

    Science.gov (United States)

    Filippidis, F T; Agaku, I T; Vardavas, C I

    2016-06-01

    Risky health behaviours such as tobacco and alcohol abuse, physical inactivity and poor diet may play an important role in disease development. The aim of the present study was to assess the geographical distribution and socio-demographic determinants of risky health-related behaviours in 27 member states (MSs) of the European Union (EU). Data from the 2009 Eurobarometer survey (wave 72.3; n = 26 788) were analysed. Tobacco use, alcohol consumption, physical activity and fruit consumption were assessed through a self-reported questionnaire provided to participants from 27 EU MSs. Within the analyses, participants with three or more lifestyle risk factors were classified as individuals with co-occurrence of risk factors. Among respondents aged 15 or older, 28.2% had none of the aforementioned behavioural risk factors, whereas 9.9% had three or more lifestyle risk factors. Males [adjusted odds ratio (aOR) = 2.50; 95% confidence interval (95% CI): 2.17-2.88] and respondents of middle (aOR = 1.60; 95% CI: 1.36-1.89) or lower income (aOR = 2.63; 95% CI: 2.12-3.26) were more likely to report co-occurrence of behavioural risk factors, as well as respondents in Northern (aOR = 1.43; 95% CI: 1.14-1.78), Western (aOR = 1.28; 95% CI: 1.06-1.56) and Eastern Europe (aOR = 1.28; 95% CI: 1.06-1.55), when compared with Southern European respondents. The above analyses indicate significant geographical and social variation in the distribution of the co-occurrence of behavioural risk factors for disease development. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. A host-endoparasite network of Neotropical marine fish: are there organizational patterns?

    Science.gov (United States)

    Bellay, Sybelle; Lima, Dilermando P; Takemoto, Ricardo M; Luque, José L

    2011-12-01

    Properties of ecological networks facilitate the understanding of interaction patterns in host-parasite systems as well as the importance of each species in the interaction structure of a community. The present study evaluates the network structure, functional role of all species and patterns of parasite co-occurrence in a host-parasite network to determine the organization level of a host-parasite system consisting of 170 taxa of gastrointestinal metazoans of 39 marine fish species on the coast of Brazil. The network proved to be nested and modular, with a low degree of connectance. Host-parasite interactions were influenced by host phylogeny. Randomness in parasite co-occurrence was observed in most modules and component communities, although species segregation patterns were also observed. The low degree of connectance in the network may be the cause of properties such as nestedness and modularity, which indicate the presence of a high number of peripheral species. Segregation patterns among parasite species in modules underscore the role of host specificity. Knowledge of ecological networks allows detection of keystone species for the maintenance of biodiversity and the conduction of further studies on the stability of networks in relation to frequent environmental changes.

  11. Environmental occurrence and ecological risk assessment of organic UV filters in marine organisms from Hong Kong coastal waters.

    Science.gov (United States)

    Sang, Ziye; Leung, Kelvin Sze-Yin

    2016-10-01

    Organic UV filters, now considered to be emerging contaminants in aquatic ecosystems, are being intensively tracked in environmental waters worldwide. However, their environmental fate and impact of these contaminants on marine organisms remains largely unknown, especially in Asia. This work elucidates the occurrence and the ecological risks of seven UV filters detected in farmed fish, wild mussels and some other wild organisms collected from local mariculture farms in Hong Kong. For all of the organisms, ethylhexyl methoxycinnamate (EHMC) and octyl dimethyl p-aminobenzoic acid (OD-PABA) were the predominant contaminants with the highest concentrations up to 51.3 and 24.1ng/g (dw), respectively; lower levels were found for benzophenone-8 (BP-8), octocrylene (OC) and benzophenone-3 (BP-3) from ecological risk assessment specific to the marine aquatic environment was carried out. The risk quotient (RQ) values of EHMC and BP-3 were calculated as 3.29 and 2.60, respectively, indicating these two UV filters may pose significant risks to the marine aquatic environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Gear-based species selectivity and potential interactions between ...

    African Journals Online (AJOL)

    ... and competition between different co-occurring fisheries is therefore important for the implementation of ecosystem based fisheries management interventions. In this study, we used multivariate and ecological approaches to evaluate gear competition and interactions between artisanal and aquarium fishers using a case ...

  13. Social interaction, co-worker altruism, and incentives

    NARCIS (Netherlands)

    Dur, R.; Sol, J.

    2010-01-01

    Social interaction with colleagues is an important job attribute for many workers. To attract and retain workers, managers therefore need to think about how to create and preserve high-quality co-worker relationships. This paper develops a principal-multi-agent model where agents do not only engage

  14. Synergetic interaction between neighbouring platinum monomers in CO2 hydrogenation

    Science.gov (United States)

    Li, Hongliang; Wang, Liangbing; Dai, Yizhou; Pu, Zhengtian; Lao, Zhuohan; Chen, Yawei; Wang, Menglin; Zheng, Xusheng; Zhu, Junfa; Zhang, Wenhua; Si, Rui; Ma, Chao; Zeng, Jie

    2018-05-01

    Exploring the interaction between two neighbouring monomers has great potential to significantly raise the performance and deepen the mechanistic understanding of heterogeneous catalysis. Herein, we demonstrate that the synergetic interaction between neighbouring Pt monomers on MoS2 greatly enhanced the CO2 hydrogenation catalytic activity and reduced the activation energy relative to isolated monomers. Neighbouring Pt monomers were achieved by increasing the Pt mass loading up to 7.5% while maintaining the atomic dispersion of Pt. Mechanistic studies reveal that neighbouring Pt monomers not only worked in synergy to vary the reaction barrier, but also underwent distinct reaction paths compared with isolated monomers. Isolated Pt monomers favour the conversion of CO2 into methanol without the formation of formic acid, whereas CO2 is hydrogenated stepwise into formic acid and methanol for neighbouring Pt monomers. The discovery of the synergetic interaction between neighbouring monomers may create a new path for manipulating catalytic properties.

  15. CyanoHAB occurrence and water irrigation cyanotoxin contamination: ecological impacts and potential health risks.

    Science.gov (United States)

    Saqrane, Sana; Oudra, Brahim

    2009-12-01

    The world-wide occurrence of harmful cyanobacteria blooms "CyanoHAB" in fresh and brackish waters creates problems for all life forms. During CyanoHAB events, toxic cyanobacteria produce cyanotoxins at high levels that can cause chronic and sub-chronic toxicities to animals, plants and humans. Cyanotoxicity in eukaryotes has been mainly focused on animals, but during these last years, data, related to cyanotoxin (mainly microcystins, MCs) impact on both aquatic and terrestrials crop plants irrigated by water containing these toxins, have become more and more available. This last cited fact is gaining importance since plants could in a direct or indirect manner contribute to cyanotoxin transfer through the food chain, and thus constitute a potent health risk source. The use of this contaminated irrigation water can also have an economical impact which appears by a reduction of the germination rate of seeds, and alteration of the quality and the productivity of crop plants. The main objective of this work was to discuss the eventual phytotoxicity of cyanotoxins (microcystins) as the major agricultural impacts induced by the use of contaminated water for plant irrigation. These investigations confirm the harmful effects (ecological, eco-physiological, socio-economical and sanitary risk) of dissolved MCs on agricultural plants. Thus, cyanotoxin phytotoxicity strongly suggests a need for the surveillance of CyanoHAB and the monitoring of water irrigation quality as well as for drinking water.

  16. Interaction between demand-control and social support in the occurrence of common mental disorders

    Directory of Open Access Journals (Sweden)

    Amália Ivine Santana Mattos

    Full Text Available ABSTRACT OBJECTIVE To analyze the interaction between the psychosocial aspects of work and the occurrence of common mental disorders among health workers. METHODS This is a cross-sectional study conducted with a representative sample of workers of the primary health care of five municipalities of the State of Bahia, Brazil, in 2012. The variable of outcome were the common mental disorders evaluated by the SRQ-20, and the variables of exposure were high demand (high psychological demand and low control over the work and low social support in the workplace. Interaction was checked by the deviation of the additivity of the effects for the factors studied from the calculation of excess risk from interaction, proportion of cases attributed to interaction, and the synergy index. RESULTS The global prevalence of common mental disorders was 21%. The group of combined exposure has shown higher magnitude (high demand and low social support, reaching 28% when compared to the 17% in the situation of no exposure (low demand and high social support. CONCLUSIONS The results strengthen the hypothesis of interaction between the factors investigated, directing to the synergy of the effects.

  17. Simultaneous assessments of occurrence, ecological, human health, and organoleptic hazards for 77 VOCs in typical drinking water sources from 5 major river basins, China

    International Nuclear Information System (INIS)

    Chen, Xichao; Luo, Qian; Wang, Donghong; Gao, Jijun; Wei, Zi; Wang, Zijian; Zhou, Huaidong; Mazumder, Asit

    2015-01-01

    Owing to the growing public awareness on the safety and aesthetics in water sources, more attention has been given to the adverse effects of volatile organic compounds (VOCs) on aquatic organisms and human beings. In this study, 77 target VOCs (including 54 common VOCs, 13 carbonyl compounds, and 10 taste and odor compounds) were detected in typical drinking water sources from 5 major river basins (the Yangtze, the Huaihe, the Yellow, the Haihe and the Liaohe River basins) and their occurrences were characterized. The ecological, human health, and olfactory assessments were performed to assess the major hazards in source water. The investigation showed that there existed potential ecological risks (1.30 × 10 ≤ RQ_t_o_t_a_ls ≤ 8.99 × 10) but little human health risks (6.84 × 10"−"7 ≤ RQ_t_o_t_a_ls ≤ 4.24 × 10"−"4) by VOCs, while that odor problems occurred extensively. The priority contaminants in drinking water sources of China were also listed based on the present assessment criteria. - Highlights: • VOCs with various polarities were screened in typical water sources of China. • Ecological, human health and olfactory assessments were simultaneously performed. • The risk assessments were used to identify the major hazards by VOCs. • The detected VOCs posed potential ecological risks but little human health risks. • Odor problems occurred extensively in source water of China. - Detected VOCs with various polarities caused odor problems and posed potential ecological risks but little human health risks in drinking water sources in China.

  18. Genetic, Ecological and Morphological Distinctness of the Blue Mussels Mytilus trossulus Gould and M. edulis L. in the White Sea.

    Directory of Open Access Journals (Sweden)

    Marina Katolikova

    Full Text Available Two blue mussel lineages of Pliocene origin, Mytilus edulis (ME and M. trossulus (MT, co-occur and hybridize in several regions on the shores of the North Atlantic. The two species were distinguished from each other by molecular methods in the 1980s, and a large amount of comparative data on them has been accumulated since that time. However, while ME and MT are now routinely distinguished by various genetic markers, they tend to be overlooked in ecological studies since morphological characters for taxonomic identification have been lacking, and no consistent habitat differences between lineages have been reported. Surveying a recently discovered area of ME and MT co-occurrence in the White Sea and employing a set of allozyme markers for identification, we address the issue whether ME and MT are true biological species with distinct ecological characteristics or just virtual genetic entities with no matching morphological and ecological identities. We find that: (1 in the White Sea, the occurrence of MT is largely concentrated in harbors, in line with observations from other subarctic regions of Europe; (2 mixed populations of ME and MT are always dominated by purebred individuals, animals classified as hybrids constituting only ca. 18%; (3 in terms of shell morphology, 80% of MT bear a distinct uninterrupted dark prismatic strip under the ligament while 97% of ME lack this character; (4 at sites of sympatry MT is more common on algal substrates while ME mostly lives directly on the bottom. This segregation by the substrate may contribute to maintaining reproductive isolation and decreasing competition between taxa. We conclude that while ME and MT are not fully reproductively isolated, they do represent clearly distinguishable biological, ecological and morphological entities in the White Sea. It remains to be documented whether the observed morphological and ecological differences are of a local character, or whether they have simply been

  19. MI-Sim: A MATLAB package for the numerical analysis of microbial ecological interactions.

    Directory of Open Access Journals (Sweden)

    Matthew J Wade

    Full Text Available Food-webs and other classes of ecological network motifs, are a means of describing feeding relationships between consumers and producers in an ecosystem. They have application across scales where they differ only in the underlying characteristics of the organisms and substrates describing the system. Mathematical modelling, using mechanistic approaches to describe the dynamic behaviour and properties of the system through sets of ordinary differential equations, has been used extensively in ecology. Models allow simulation of the dynamics of the various motifs and their numerical analysis provides a greater understanding of the interplay between the system components and their intrinsic properties. We have developed the MI-Sim software for use with MATLAB to allow a rigorous and rapid numerical analysis of several common ecological motifs. MI-Sim contains a series of the most commonly used motifs such as cooperation, competition and predation. It does not require detailed knowledge of mathematical analytical techniques and is offered as a single graphical user interface containing all input and output options. The tools available in the current version of MI-Sim include model simulation, steady-state existence and stability analysis, and basin of attraction analysis. The software includes seven ecological interaction motifs and seven growth function models. Unlike other system analysis tools, MI-Sim is designed as a simple and user-friendly tool specific to ecological population type models, allowing for rapid assessment of their dynamical and behavioural properties.

  20. MI-Sim: A MATLAB package for the numerical analysis of microbial ecological interactions.

    Science.gov (United States)

    Wade, Matthew J; Oakley, Jordan; Harbisher, Sophie; Parker, Nicholas G; Dolfing, Jan

    2017-01-01

    Food-webs and other classes of ecological network motifs, are a means of describing feeding relationships between consumers and producers in an ecosystem. They have application across scales where they differ only in the underlying characteristics of the organisms and substrates describing the system. Mathematical modelling, using mechanistic approaches to describe the dynamic behaviour and properties of the system through sets of ordinary differential equations, has been used extensively in ecology. Models allow simulation of the dynamics of the various motifs and their numerical analysis provides a greater understanding of the interplay between the system components and their intrinsic properties. We have developed the MI-Sim software for use with MATLAB to allow a rigorous and rapid numerical analysis of several common ecological motifs. MI-Sim contains a series of the most commonly used motifs such as cooperation, competition and predation. It does not require detailed knowledge of mathematical analytical techniques and is offered as a single graphical user interface containing all input and output options. The tools available in the current version of MI-Sim include model simulation, steady-state existence and stability analysis, and basin of attraction analysis. The software includes seven ecological interaction motifs and seven growth function models. Unlike other system analysis tools, MI-Sim is designed as a simple and user-friendly tool specific to ecological population type models, allowing for rapid assessment of their dynamical and behavioural properties.

  1. Predicting the sensitivity of populations from individual exposure to chemicals: the role of ecological interactions.

    Science.gov (United States)

    Gabsi, Faten; Schäffer, Andreas; Preuss, Thomas G

    2014-07-01

    Population responses to chemical stress exposure are influenced by nonchemical, environmental processes such as species interactions. A realistic quantification of chemical toxicity to populations calls for the use of methodologies that integrate these multiple stress effects. The authors used an individual-based model for Daphnia magna as a virtual laboratory to determine the influence of ecological interactions on population sensitivity to chemicals with different modes of action on individuals. In the model, hypothetical chemical toxicity targeted different vital individual-level processes: reproduction, survival, feeding rate, or somatic growth rate. As for species interactions, predatory and competition effects on daphnid populations were implemented following a worst-case approach. The population abundance was simulated at different food levels and exposure scenarios, assuming exposure to chemical stress solely or in combination with either competition or predation. The chemical always targeted one vital endpoint. Equal toxicity-inhibition levels differently affected the population abundance with and without species interactions. In addition, population responses to chemicals were highly sensitive to the environmental stressor (predator or competitor) and to the food level. Results show that population resilience cannot be attributed to chemical stress only. Accounting for the relevant ecological interactions would reduce uncertainties when extrapolating effects of chemicals from individuals to the population level. Validated population models should be used for a more realistic risk assessment of chemicals. © 2014 SETAC.

  2. Co-occurrence of personality disorders in persons with kleptomania: a preliminary investigation.

    Science.gov (United States)

    Grant, Jon E

    2004-01-01

    This study was conducted to examine the co-occurrence of personality disorders in a group of persons with kleptomania. Twenty-eight subjects with DSM-IV kleptomania were administered the Structured Clinical Interview for DSM-III-R Personality Disorders and a semistructured interview to assess demographics and clinical characteristics. Twelve subjects with kleptomania (42.9%) met criteria for at least one personality disorder. The most common were: paranoid (n = 5; 17.9%), schizoid (n = 3; 10.7%), and borderline (n = 3; 10.7%). Subjects with kleptomania combined with personality disorders had an earlier age of onset of stealing behavior (13.4 +/- 5.6 years compared with 27.4 +/- 14.2 years in those who had kleptomania only; t = 3.225; df = 26; p = .006). Severity of kleptomania symptoms did not differ among the Axis II comorbidities. Persons with kleptomania appear to have a high prevalence of personality disorders. Further studies are needed to understand the relationship of kleptomania to personality.

  3. No boundaries: genomes, organisms, and ecological interactions responsible for divergence and reproductive isolation.

    Science.gov (United States)

    Etges, William J

    2014-01-01

    Revealing the genetic basis of traits that cause reproductive isolation, particularly premating or sexual isolation, usually involves the same challenges as most attempts at genotype-phenotype mapping and so requires knowledge of how these traits are expressed in different individuals, populations, and environments, particularly under natural conditions. Genetic dissection of speciation phenotypes thus requires understanding of the internal and external contexts in which underlying genetic elements are expressed. Gene expression is a product of complex interacting factors internal and external to the organism including developmental programs, the genetic background including nuclear-cytotype interactions, epistatic relationships, interactions among individuals or social effects, stochasticity, and prevailing variation in ecological conditions. Understanding of genomic divergence associated with reproductive isolation will be facilitated by functional expression analysis of annotated genomes in organisms with well-studied evolutionary histories, phylogenetic affinities, and known patterns of ecological variation throughout their life cycles. I review progress and prospects for understanding the pervasive role of host plant use on genetic and phenotypic expression of reproductive isolating mechanisms in cactophilic Drosophila mojavensis and suggest how this system can be used as a model for revealing the genetic basis for species formation in organisms where speciation phenotypes are under the joint influences of genetic and environmental factors. © The American Genetic Association. 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence

    OpenAIRE

    Ladle, Andrew; Steenweg, Robin; Shepherd, Brenda; Boyce, Mark S.

    2018-01-01

    Species' distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use....

  5. The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence

    OpenAIRE

    Ladle, Andrew; Steenweg, Robin; Shepherd, Brenda; Boyce, Mark S.

    2018-01-01

    Species’ distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use....

  6. Occurrence of avian Plasmodium and West Nile virus in culex species in Wisconsin

    Science.gov (United States)

    Hughes, T.; Irwin, P.; Hofmeister, E.; Paskewitz, S.M.

    2010-01-01

    The occurrence of multiple pathogens in mosquitoes and birds could affect the dynamics of disease transmission. We collected adult Culex pipiens and Cx. restuans (Cx. pipiens/restuans hereafter) from sites in Wisconsin and tested them for West Nile virus (WNV) and for avian malaria (Plasmodium). Gravid Cx. pipiens/restuans were tested for WNV using a commercial immunoassay, the RAMP?? WNV test, and positive results were verified by reverse transcriptasepolymerase chain reaction. There were 2 WNV-positive pools of Cx. pipiens/restuans in 2006 and 1 in 2007. Using a bias-corrected maximum likelihood estimation, the WNV infection rate for Cx. pipiens/restuans was 5.48/1,000 mosquitoes in 2006 and 1.08/1,000 mosquitoes in 2007. Gravid Cx. pipiens or Cx. restuans were tested individually for avian Plasmodium by a restriction enzymebased assay. Twelve mosquitoes were positive for avian Plasmodium (10.0), 2 were positive for Haemoproteus, and 3 were positive for Leucocytozoon. There were 4 mixed infections, with mosquitoes positive for >1 of the hemosporidian parasites. This work documents a high rate of hemosporidian infection in Culex spp. and illustrates the potential for co-infections with other arboviruses in bird-feeding mosquitoes and their avian hosts. In addition, hemosporidian infection rates may be a useful tool for investigating the ecological dynamics of Culex/avian interactions. ?? 2010 by The American Mosquito Control Association, Inc.

  7. Method Development, Monitoring, and Occurrence of Microcystins in Ambient Water

    Science.gov (United States)

    The occurrence and intensity of cyanobacterial harmful blooms have become increasingly common over the last few decades. Cyanobacteria are a worldwide concern in areas with eutrophic water conditions. Cyanotoxins generated from cyanobacteria are harmful ecologically, cause econom...

  8. Aspects of elephant behavior, ecology, and interactions with humans

    Science.gov (United States)

    O'Connell, Caitlin Elizabeth

    This dissertation is comprised of two chapters relating to the acoustic behavior of elephants, their surrounding ecology and interactions with humans. The first chapter investigates the seismic aspects of Asian elephant (Elephus maximus) acoustic communication. The second chapter is comprised of a synthesis of two separate studies conducted on the African elephant (Loxodonta africana) in Namibia, both in Etosha National Park and the Caprivi region. The two studies were combined and published in Biological Conservation as one large study on aspects of the economic and social impacts of elephant/human conflict and experiments conducted to reduce conflict. In chapter one, seismic and acoustic data were recorded simultaneously from Asian elephants during periods of vocalizations and locomotion. Acoustic and seismic signals from rumbles were highly correlated at near and far distances and were in phase near the elephant and were out of phase at an increased distance from the elephant. Data analyses indicated that elephant generated signals associated with rumbles and "foot stomps" propagated at different velocities in the two media, the acoustic signals traveling at 309 m/s and the seismic signals at 248--264 m/s. Both types of signals had predominant frequencies in the range of 20 Hz. Seismic signal amplitudes considerably above background noise were recorded at 40 m from the generating elephants for both the rumble and the stomp. Seismic propagation models suggest that seismic waveforms from vocalizations are potentially detectable by instruments at distances of up to 16 km, and up to 32 km for locomotion generated signals. Thus, if detectable by elephants, these seismic signals could be useful for long distance communication. In chapter two, the economic impact of elephants, Loxodonta africana , and predators, particularly lions, Panthera leo, on rural agriculturists in the Kwando region of the East Caprivi, Namibia was assessed from the years 1991 to 1995. Elephants

  9. Network analysis of named entity co-occurrences in written texts

    Science.gov (United States)

    Amancio, Diego Raphael

    2016-06-01

    The use of methods borrowed from statistics and physics to analyze written texts has allowed the discovery of unprecedent patterns of human behavior and cognition by establishing links between models features and language structure. While current models have been useful to unveil patterns via analysis of syntactical and semantical networks, only a few works have probed the relevance of investigating the structure arising from the relationship between relevant entities such as characters, locations and organizations. In this study, we represent entities appearing in the same context as a co-occurrence network, where links are established according to a null model based on random, shuffled texts. Computational simulations performed in novels revealed that the proposed model displays interesting topological features, such as the small world feature, characterized by high values of clustering coefficient. The effectiveness of our model was verified in a practical pattern recognition task in real networks. When compared with traditional word adjacency networks, our model displayed optimized results in identifying unknown references in texts. Because the proposed representation plays a complementary role in characterizing unstructured documents via topological analysis of named entities, we believe that it could be useful to improve the characterization of written texts (and related systems), specially if combined with traditional approaches based on statistical and deeper paradigms.

  10. The raison d'être of chemical ecology.

    Science.gov (United States)

    Raguso, Robert A; Agrawal, Anurag A; Douglas, Angela E; Jander, Georg; Kessler, André; Poveda, Katja; Thaler, Jennifer S

    2015-03-01

    Chemical ecology is a mechanistic approach to understanding the causes and consequences of species interactions, distribution, abundance, and diversity. The promise of chemical ecology stems from its potential to provide causal mechanisms that further our understanding of ecological interactions and allow us to more effectively manipulate managed systems. Founded on the notion that all organisms use endogenous hormones and chemical compounds that mediate interactions, chemical ecology has flourished over the past 50 years since its origin. In this essay we highlight the breadth of chemical ecology, from its historical focus on pheromonal communication, plant-insect interactions, and coevolution to frontier themes including community and ecosystem effects of chemically mediated species interactions. Emerging approaches including the -omics, phylogenetic ecology, the form and function of microbiomes, and network analysis, as well as emerging challenges (e.g., sustainable agriculture and public health) are guiding current growth of this field. Nonetheless, the directions and approaches we advocate for the future are grounded in classic ecological theories and hypotheses that continue to motivate our broader discipline.

  11. Individual and Interactive Influences of Anthropogenic and Ecological Factors on Forest PM2.5 Concentrations at an Urban Scale

    Directory of Open Access Journals (Sweden)

    Guoliang Yun

    2018-03-01

    Full Text Available Integration of Landsat images and multisource data using spatial statistical analysis and geographical detector models can reveal the individual and interactive influences of anthropogenic activities and ecological factors on concentrations of atmospheric particulate matter less than 2.5 microns in diameter (PM2.5. This approach has been used in many studies to estimate biomass and forest disturbance patterns and to monitor carbon sinks. However, the approach has rarely been used to comprehensively analyze the individual and interactive influences of anthropogenic factors (e.g., population density, impervious surface percentage and ecological factors (e.g., canopy density, stand age, and elevation on PM2.5 concentrations. To do this, we used Landsat-8 images and meteorological data to retrieve quantitative data on the concentrations of particulates (PM2.5, then integrated a forest management planning inventory (FMPI, population density distribution data, meteorological data, and topographic data in a Geographic Information System database, and applied a spatial statistical analysis model to identify aggregated areas (hot spots and cold spots of particulates in the urban area of Jinjiang city, China. A geographical detector model was used to analyze the individual and interactive influences of anthropogenic and ecological factors on PM2.5 concentrations. We found that particulate concentration hot spots are mainly distributed in urban centers and suburbs, while cold spots are mainly distributed in the suburbs and exurban region. Elevation was the dominant individual factor affecting PM2.5 concentrations, followed by dominant tree species and meteorological factors. A combination of human activities (e.g., population density, impervious surface percentage and multiple ecological factors caused the dominant interactive effects, resulting in increased PM2.5 concentrations. Our study suggests that human activities and multiple ecological factors

  12. 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.

  13. Network of interactions between ciliates and phytoplankton during spring

    Directory of Open Access Journals (Sweden)

    Thomas ePosch

    2015-11-01

    Full Text Available The annually recurrent spring phytoplankton blooms in freshwater lakes initiate pronounced successions of planktonic ciliate species. Although there is considerable knowledge on the taxonomic diversity of these ciliates, their species-specific interactions with other microorganisms are still not well understood. Here we present the succession patterns of 20 morphotypes of ciliates during spring in Lake Zurich, Switzerland, and we relate their abundances to phytoplankton genera, flagellates, heterotrophic bacteria, and abiotic parameters. Interspecific relationships were analyzed by contemporaneous correlations and time-lagged co-occurrence and visualized as association networks. The contemporaneous network pointed to the pivotal role of distinct ciliate species (e.g., Balanion planctonicum, Rimostrombidium humile as primary consumers of cryptomonads, revealed a clear overclustering of mixotrophic / omnivorous species, and highlighted the role of Halteria / Pelagohalteria as important bacterivores. By contrast, time-lagged statistical approaches (like local similarity analyses, LSA proved to be inadequate for the evaluation of high-frequency sampling data. LSA led to a conspicuous inflation of significant associations, making it difficult to establish ecologically plausible interactions between ciliates and other microorganisms. Nevertheless, if adequate statistical procedures are selected, association networks can be powerful tools to formulate testable hypotheses about the autecology of only recently described ciliate species.

  14. From Ecological Sounding Artifacts Towards Sonic Artifact Ecologies

    DEFF Research Database (Denmark)

    Erkut, Cumhur; Serafin, Stefania

    2016-01-01

    The discipline of sonic interaction design has been focused on the interaction between a single user and an artifact. This strongly limits one of the fundamental aspects of music as a social and interactive experience. In this paper we propose sonic artifact ecologies as a mean to examine interac...

  15. Genetic insights into family group co-occurrence in Cryptocercus punctulatus, a sub-social woodroach from the southern Appalachian Mountains

    Directory of Open Access Journals (Sweden)

    Ryan C. Garrick

    2017-03-01

    Full Text Available The wood-feeding cockroach Cryptocercus punctulatus Scudder (Blattodea: Cryptocercidae is an important member of the dead wood (saproxylic community in montane forests of the southeastern United States. However, its population biology remains poorly understood. Here, aspects of family group co-occurrence were characterized to provide basic information that can be extended by studies on the evolution and maintenance of sub-sociality. Broad sampling across the species’ range was coupled with molecular data (mitochondrial DNA (mtDNA sequences. The primary questions were: (1 what proportion of rotting logs contain two or more different mtDNA haplotypes and how often can this be attributed to multiple families inhabiting the same log, (2 are multi-family logs spatially clustered, and (3 what levels of genetic differentiation among haplotypes exist within a log, and how genetically similar are matrilines of co-occurring family groups? Multi-family logs were identified on the premise that three different mtDNA haplotypes, or two different haplotypes among adult females, is inconsistent with a single family group founded by one male–female pair. Results showed that of the 88 rotting logs from which multiple adult C. punctulatus were sampled, 41 logs (47% contained two or more mtDNA haplotypes, and at least 19 of these logs (22% overall were inferred to be inhabited by multiple families. There was no strong evidence for spatial clustering of the latter class of logs. The frequency distribution of nucleotide differences between co-occurring haplotypes was strongly right-skewed, such that most haplotypes were only one or two mutations apart, but more substantial divergences (up to 18 mutations, or 1.6% uncorrected sequence divergence do occasionally occur within logs. This work represents the first explicit investigation of family group co-occurrence in C. punctulatus, providing a valuable baseline for follow-up studies.

  16. 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...

  17. Core Data of Yeast Interacting Proteins Database (Annotation Updated Version) - Yeast Interacting Proteins Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available hod As the indicator of reliability of the interactions obtained by the experiment, the literature informati...ic Acids Res. 28, 73-76.) are used for literature collection. Number of data entries 841 interactions Data i...d from the YPD. Literature sharing score The score concerning co-occurrence of Prey and Bait in the litera...ture, calculated by the calculation formula. Calculation formula for the score: Cur

  18. Viral coinfection is shaped by host ecology and virus-virus interactions across diverse microbial taxa and environments.

    Science.gov (United States)

    Díaz-Muñoz, Samuel L

    2017-01-01

    Infection of more than one virus in a host, coinfection, is common across taxa and environments. Viral coinfection can enable genetic exchange, alter the dynamics of infections, and change the course of viral evolution. Yet, a systematic test of the factors explaining variation in viral coinfection across different taxa and environments awaits completion. Here I employ three microbial data sets of virus-host interactions covering cross-infectivity, culture coinfection, and single-cell coinfection (total: 6,564 microbial hosts, 13,103 viruses) to provide a broad, comprehensive picture of the ecological and biological factors shaping viral coinfection. I found evidence that ecology and virus-virus interactions are recurrent factors shaping coinfection patterns. Host ecology was a consistent and strong predictor of coinfection across all three data sets: cross-infectivity, culture coinfection, and single-cell coinfection. Host phylogeny or taxonomy was a less consistent predictor, being weak or absent in the cross-infectivity and single-cell coinfection models, yet it was the strongest predictor in the culture coinfection model. Virus-virus interactions strongly affected coinfection. In the largest test of superinfection exclusion to date, prophage sequences reduced culture coinfection by other prophages, with a weaker effect on extrachromosomal virus coinfection. At the single-cell level, prophage sequences eliminated coinfection. Virus-virus interactions also increased culture coinfection with ssDNA-dsDNA coinfections >2× more likely than ssDNA-only coinfections. The presence of CRISPR spacers was associated with a ∼50% reduction in single-cell coinfection in a marine bacteria, despite the absence of exact spacer matches in any active infection. Collectively, these results suggest the environment bacteria inhabit and the interactions among surrounding viruses are two factors consistently shaping viral coinfection patterns. These findings highlight the role of

  19. Are trade-offs among species' ecological interactions scale dependent? A test using pitcher-plant inquiline species.

    Science.gov (United States)

    Kneitel, Jamie M

    2012-01-01

    Trade-offs among species' ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species' ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species' traits in the context of coexistence at different scales

  20. Interactive network configuration maintains bacterioplankton community structure under elevated CO2 in a eutrophic coastal mesocosm experiment

    Science.gov (United States)

    Lin, Xin; Huang, Ruiping; Li, Yan; Li, Futian; Wu, Yaping; Hutchins, David A.; Dai, Minhan; Gao, Kunshan

    2018-01-01

    There is increasing concern about the effects of ocean acidification on marine biogeochemical and ecological processes and the organisms that drive them, including marine bacteria. Here, we examine the effects of elevated CO2 on the bacterioplankton community during a mesocosm experiment using an artificial phytoplankton community in subtropical, eutrophic coastal waters of Xiamen, southern China. Through sequencing the bacterial 16S rRNA gene V3-V4 region, we found that the bacterioplankton community in this high-nutrient coastal environment was relatively resilient to changes in seawater carbonate chemistry. Based on comparative ecological network analysis, we found that elevated CO2 hardly altered the network structure of high-abundance bacterioplankton taxa but appeared to reassemble the community network of low abundance taxa. This led to relatively high resilience of the whole bacterioplankton community to the elevated CO2 level and associated chemical changes. We also observed that the Flavobacteria group, which plays an important role in the microbial carbon pump, showed higher relative abundance under the elevated CO2 condition during the early stage of the phytoplankton bloom in the mesocosms. Our results provide new insights into how elevated CO2 may influence bacterioplankton community structure.

  1. EFFECTS OF VARIOUS SOIL ENVIRONMENTAL STRESSES ON THE OCCURRENCE, DISTRIBUTION AND EFFECTIVENESS OF VA MYCORRHIZAE

    Directory of Open Access Journals (Sweden)

    A.G. KHAN

    1995-01-01

    Full Text Available The vesicular - arbuscular (VA mycorrhizal fungi are geographically ubiquitous soil inhabitants and form universal symbiotic relationship with plants from every phylum. These fungi link host plants with host soils and their biota in the mycorrhizosphere and play an important role in plant health, productivity and soil structure. Although VA mycorrhizal fungi do not show any host specificity, there is increasing evidence that various climatic and edaphic environmental factors such as land use and management practices, physical, chemical and biological properties of host soils and host plant characteristics influence their occurrence, taxonomic distribution and effectiveness. The interaction of these factors with vesicular-arbuscular mycorrhizae (VAM is poorly understood except in a few cases. It is now very clear that VA mycorrhizal associations are ecologically significant factors that require more attention than previously accorded. This paper discusses the occurrence, distribution and significance of VAM in environmentally stressed soil conditions that limit plant growth such as drought, waterlogging and salinity.

  2. Occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal marine sediments along the shoreline of Douglas Channel to Hecate Strait in British Columbia.

    Science.gov (United States)

    Yang, Zeyu; Hollebone, Bruce P; Laforest, Sonia; Lambert, Patrick; Brown, Carl E; Yang, Chun; Shah, Keval; Landriault, Mike; Goldthorp, Michael

    2017-09-15

    The occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal zone along the northern British shoreline were evaluated based on analyzing total petroleum hydrocarbons (TPH), n-alkanes, petroleum related biomarkers such as terpanes and steranes, and polycyclic aromatic hydrocarbons (PAHs) including non-alkylated and alkylated homologues (APAHs). The TPH levels, n-alkanes, petroleum biomarkers and PAHs in all the sampling sites, except for Masset Harbor/York Point at Gil Island were low, without obvious unresolved complex mixture (UCM) and petroleum contamination input. Specifically, n-alkanes showed a major terrestrial plants input; PAHs with abundant non-alkylated PAHs but minor APAHs showed a major pyrogenic input. However, obvious petroleum-derived hydrocarbons have impacted Masset Harbor. A historical petroleum input was found in York Point at Gil Island, due to the presence of the low level of petroleum biomarkers. Ecological assessment of 13 non-alkylated PAHs in Masset Harbor indicated no potential toxicity to the benthic organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Host-to-host variation of ecological interactions in polymicrobial infections

    International Nuclear Information System (INIS)

    Mukherjee, Sayak; Seok, Sang-Cheol; Ray, Will C; Jayaprakash, C; Vieland, Veronica J; Das, Jayajit; Weimer, Kristin E; Swords, W Edward

    2015-01-01

    Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used to analyze host–microorganism relationships, as well as most of the ecological theories proposed to explain coevolution of hosts and microbes, are based on averages across a host population. By assuming that observed variations are random and independent, these models overlook the role of differences between hosts. Here, we analyze mechanisms underlying host-to-host variations of bacterial infection kinetics, using the well characterized experimental infection model of polymicrobial otitis media (OM) in chinchillas, in combination with population dynamic models and a maximum entropy (MaxEnt) based inference scheme. We find that the nature of the interactions between bacterial species critically regulates host-to-host variations in these interactions. Surprisingly, seemingly unrelated phenomena, such as the efficiency of individual bacterial species in utilizing nutrients for growth, and the microbe-specific host immune response, can become interdependent in a host population. The latter finding suggests a potential mechanism that could lead to selection of specific strains of bacterial species during the coevolution of the host immune response and the bacterial species. (paper)

  4. Host-to-host variation of ecological interactions in polymicrobial infections

    Science.gov (United States)

    Mukherjee, Sayak; Weimer, Kristin E.; Seok, Sang-Cheol; Ray, Will C.; Jayaprakash, C.; Vieland, Veronica J.; Swords, W. Edward; Das, Jayajit

    2015-02-01

    Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used to analyze host-microorganism relationships, as well as most of the ecological theories proposed to explain coevolution of hosts and microbes, are based on averages across a host population. By assuming that observed variations are random and independent, these models overlook the role of differences between hosts. Here, we analyze mechanisms underlying host-to-host variations of bacterial infection kinetics, using the well characterized experimental infection model of polymicrobial otitis media (OM) in chinchillas, in combination with population dynamic models and a maximum entropy (MaxEnt) based inference scheme. We find that the nature of the interactions between bacterial species critically regulates host-to-host variations in these interactions. Surprisingly, seemingly unrelated phenomena, such as the efficiency of individual bacterial species in utilizing nutrients for growth, and the microbe-specific host immune response, can become interdependent in a host population. The latter finding suggests a potential mechanism that could lead to selection of specific strains of bacterial species during the coevolution of the host immune response and the bacterial species.

  5. Host-to-host variation of ecological interactions in polymicrobial infections.

    Science.gov (United States)

    Mukherjee, Sayak; Weimer, Kristin E; Seok, Sang-Cheol; Ray, Will C; Jayaprakash, C; Vieland, Veronica J; Swords, W Edward; Das, Jayajit

    2014-12-04

    Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used to analyze host-microorganism relationships, as well as most of the ecological theories proposed to explain coevolution of hosts and microbes, are based on averages across a host population. By assuming that observed variations are random and independent, these models overlook the role of differences between hosts. Here, we analyze mechanisms underlying host-to-host variations of bacterial infection kinetics, using the well characterized experimental infection model of polymicrobial otitis media (OM) in chinchillas, in combination with population dynamic models and a maximum entropy (MaxEnt) based inference scheme. We find that the nature of the interactions between bacterial species critically regulates host-to-host variations in these interactions. Surprisingly, seemingly unrelated phenomena, such as the efficiency of individual bacterial species in utilizing nutrients for growth, and the microbe-specific host immune response, can become interdependent in a host population. The latter finding suggests a potential mechanism that could lead to selection of specific strains of bacterial species during the coevolution of the host immune response and the bacterial species.

  6. Changing ASD-ADHD symptom co-occurrence across the lifespan with adolescence as crucial time window : Illustrating the need to go beyond childhood

    NARCIS (Netherlands)

    Hartman, Catharina A.; Geurts, Hilde M.; Franke, Barbara; Buitelaar, Jan K.; Rommelse, Nanda N. J.

    2016-01-01

    Literature on the co-occurrence between Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) is strongly biased by a focus on childhood age. A review of the adolescent and adult literature was made on core and related symptoms of ADHD and ASD. In addition, an empirical

  7. Plant-ants use symbiotic fungi as a food source: new insight into the nutritional ecology of ant-plant interactions.

    Science.gov (United States)

    Blatrix, Rumsaïs; Djiéto-Lordon, Champlain; Mondolot, Laurence; La Fisca, Philippe; Voglmayr, Hermann; McKey, Doyle

    2012-10-07

    Usually studied as pairwise interactions, mutualisms often involve networks of interacting species. Numerous tropical arboreal ants are specialist inhabitants of myrmecophytes (plants bearing domatia, i.e. hollow structures specialized to host ants) and are thought to rely almost exclusively on resources derived from the host plant. Recent studies, following up on century-old reports, have shown that fungi of the ascomycete order Chaetothyriales live in symbiosis with plant-ants within domatia. We tested the hypothesis that ants use domatia-inhabiting fungi as food in three ant-plant symbioses: Petalomyrmex phylax/Leonardoxa africana, Tetraponera aethiops/Barteria fistulosa and Pseudomyrmex penetrator/Tachigali sp. Labelling domatia fungal patches in the field with either a fluorescent dye or (15)N showed that larvae ingested domatia fungi. Furthermore, when the natural fungal patch was replaced with a piece of a (15)N-labelled pure culture of either of two Chaetothyriales strains isolated from T. aethiops colonies, these fungi were also consumed. These two fungi often co-occur in the same ant colony. Interestingly, T. aethiops workers and larvae ingested preferentially one of the two strains. Our results add a new piece in the puzzle of the nutritional ecology of plant-ants.

  8. Plant-ants use symbiotic fungi as a food source: new insight into the nutritional ecology of ant–plant interactions

    Science.gov (United States)

    Blatrix, Rumsaïs; Djiéto-Lordon, Champlain; Mondolot, Laurence; La Fisca, Philippe; Voglmayr, Hermann; McKey, Doyle

    2012-01-01

    Usually studied as pairwise interactions, mutualisms often involve networks of interacting species. Numerous tropical arboreal ants are specialist inhabitants of myrmecophytes (plants bearing domatia, i.e. hollow structures specialized to host ants) and are thought to rely almost exclusively on resources derived from the host plant. Recent studies, following up on century-old reports, have shown that fungi of the ascomycete order Chaetothyriales live in symbiosis with plant-ants within domatia. We tested the hypothesis that ants use domatia-inhabiting fungi as food in three ant–plant symbioses: Petalomyrmex phylax/Leonardoxa africana, Tetraponera aethiops/Barteria fistulosa and Pseudomyrmex penetrator/Tachigali sp. Labelling domatia fungal patches in the field with either a fluorescent dye or 15N showed that larvae ingested domatia fungi. Furthermore, when the natural fungal patch was replaced with a piece of a 15N-labelled pure culture of either of two Chaetothyriales strains isolated from T. aethiops colonies, these fungi were also consumed. These two fungi often co-occur in the same ant colony. Interestingly, T. aethiops workers and larvae ingested preferentially one of the two strains. Our results add a new piece in the puzzle of the nutritional ecology of plant-ants. PMID:22859596

  9. 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.

  10. Novel co-culture plate enables growth dynamic-based assessment of contact-independent microbial interactions.

    Directory of Open Access Journals (Sweden)

    Thomas J Moutinho

    Full Text Available Interactions between microbes are central to the dynamics of microbial communities. Understanding these interactions is essential for the characterization of communities, yet challenging to accomplish in practice. There are limited available tools for characterizing diffusion-mediated, contact-independent microbial interactions. A practical and widely implemented technique in such characterization involves the simultaneous co-culture of distinct bacterial species and subsequent analysis of relative abundance in the total population. However, distinguishing between species can be logistically challenging. In this paper, we present a low-cost, vertical membrane, co-culture plate to quantify contact-independent interactions between distinct bacterial populations in co-culture via real-time optical density measurements. These measurements can be used to facilitate the analysis of the interaction between microbes that are physically separated by a semipermeable membrane yet able to exchange diffusible molecules. We show that diffusion across the membrane occurs at a sufficient rate to enable effective interaction between physically separate cultures. Two bacterial species commonly found in the cystic fibrotic lung, Pseudomonas aeruginosa and Burkholderia cenocepacia, were co-cultured to demonstrate how this plate may be implemented to study microbial interactions. We have demonstrated that this novel co-culture device is able to reliably generate real-time measurements of optical density data that can be used to characterize interactions between microbial species.

  11. Ecology of the Nevada Test Site. I. Geographic and ecologic distributions of the vascular flora (annotated checklist)

    Energy Technology Data Exchange (ETDEWEB)

    Beatley, J C

    1965-04-01

    A checklist of vascular plants of the Nevada Test Site is presented for use in studies of plant ecology. Data on the occurrence and distribution of plant species are included. Collections were made from both undisturbed and disturbed sites.

  12. Predicting Seagrass Occurrence in a Changing Climate Using Random Forests

    Science.gov (United States)

    Aydin, O.; Butler, K. A.

    2017-12-01

    Seagrasses are marine plants that can quickly sequester vast amounts of carbon (up to 100 times more and 12 times faster than tropical forests). In this work, we present an integrated GIS and machine learning approach to build a data-driven model of seagrass presence-absence. We outline a random forest approach that avoids the prevalence bias in many ecological presence-absence models. One of our goals is to predict global seagrass occurrence from a spatially limited training sample. In addition, we conduct a sensitivity study which investigates the vulnerability of seagrass to changing climate conditions. We integrate multiple data sources including fine-scale seagrass data from MarineCadastre.gov and the recently available globally extensive publicly available Ecological Marine Units (EMU) dataset. These data are used to train a model for seagrass occurrence along the U.S. coast. In situ oceans data are interpolated using Empirical Bayesian Kriging (EBK) to produce globally extensive prediction variables. A neural network is used to estimate probable future values of prediction variables such as ocean temperature to assess the impact of a warming climate on seagrass occurrence. The proposed workflow can be generalized to many presence-absence models.

  13. Recent advances in dental biofilm: impacts of microbial interactions on the biofilm ecology and pathogenesis

    Directory of Open Access Journals (Sweden)

    Yung-Hua Li

    2017-05-01

    Full Text Available The human oral cavity is a complex ecosystem harboring hundreds species of microbes that are largely living on the tooth surfaces as dental biofilms. Most microbes in dental biofilms promote oral health by stimulating the immune system or by preventing invasion of pathogens. Species diversity, high cell density and close proximity of cells are typical of life in dental biofilms, where microbes interact with each other and develop complex interactions that can be either competitive or cooperative. Competition between species is a well-recognized ecological force to drive microbial metabolism, species diversity and evolution. However, it was not until recently that microbial cooperative activities are also recognized to play important roles in microbial physiology and ecology. Importantly, these interactions profoundly affect the overall biomass, function, diversity and the pathogenesis in dental biofilms. It is now recognized that every human body contains a personalized oral microbiome that is essential to maintaining the oral health. Remarkably, the indigenous species in dental biofilms often maintain a relatively stable and harmless relationship with the host, despite regular exposure to environmental perturbations and the host defense factors. Such stability or homeostasis results from a dynamic balance of microbial-microbial and microbial-host interactions. Under certain circumstances, however, the homeostasis may breakdown, predisposing a site to diseases. In this review, we describe several examples of microbial interactions and their impacts on the homeostasis and pathogenesis of dental biofilms. We hope to encourage research on microbial interactions in the regulation of the homeostasis in biofilms.

  14. Ecological specialization and morphological diversification in Greater Antillean boas.

    Science.gov (United States)

    Reynolds, R Graham; Collar, David C; Pasachnik, Stesha A; Niemiller, Matthew L; Puente-Rolón, Alberto R; Revell, Liam J

    2016-08-01

    Colonization of islands can dramatically influence the evolutionary trajectories of organisms, with both deterministic and stochastic processes driving adaptation and diversification. Some island colonists evolve extremely large or small body sizes, presumably in response to unique ecological circumstances present on islands. One example of this phenomenon, the Greater Antillean boas, includes both small (<90 cm) and large (4 m) species occurring on the Greater Antilles and Bahamas, with some islands supporting pairs or trios of body-size divergent species. These boas have been shown to comprise a monophyletic radiation arising from a Miocene dispersal event to the Greater Antilles, though it is not known whether co-occurrence of small and large species is a result of dispersal or in situ evolution. Here, we provide the first comprehensive species phylogeny for this clade combined with morphometric and ecological data to show that small body size evolved repeatedly on separate islands in association with specialization in substrate use. Our results further suggest that microhabitat specialization is linked to increased rates of head shape diversification among specialists. Our findings show that ecological specialization following island colonization promotes morphological diversity through deterministic body size evolution and cranial morphological diversification that is contingent on island- and species-specific factors. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  15. Limitations in global information on species occurrences

    Directory of Open Access Journals (Sweden)

    Carsten Meyer

    2016-07-01

    Full Text Available Detailed information on species distributions is crucial for answering central questions in biogeography, ecology, evolutionary biology and conservation. Millions of species occurrence records have been mobilized via international data-sharing networks, but inherent biases, gaps and uncertainties hamper broader application. In my PhD thesis, I presented the first comprehensive analyses of global patterns and drivers of these limitations across different taxonomic groups and spatial scales. Integrating 300 million occurrence records for terrestrial vertebrates and plants with comprehensive taxonomic databases, expert range maps and regional checklists, I demonstrated extensive taxonomic, geographical and temporal biases, gaps and uncertainties. I identified key socio-economic drivers of data bias across different taxonomic groups and spatial scales. The results of my dissertation provide an empirical baseline for effectively accounting for data limitations in distribution models, as well as for prioritizing and monitoring efforts to collate additional occurrence information.

  16. Co-occurrence graphs for word sense disambiguation in the biomedical domain.

    Science.gov (United States)

    Duque, Andres; Stevenson, Mark; Martinez-Romo, Juan; Araujo, Lourdes

    2018-05-01

    Word sense disambiguation is a key step for many natural language processing tasks (e.g. summarization, text classification, relation extraction) and presents a challenge to any system that aims to process documents from the biomedical domain. In this paper, we present a new graph-based unsupervised technique to address this problem. The knowledge base used in this work is a graph built with co-occurrence information from medical concepts found in scientific abstracts, and hence adapted to the specific domain. Unlike other unsupervised approaches based on static graphs such as UMLS, in this work the knowledge base takes the context of the ambiguous terms into account. Abstracts downloaded from PubMed are used for building the graph and disambiguation is performed using the personalized PageRank algorithm. Evaluation is carried out over two test datasets widely explored in the literature. Different parameters of the system are also evaluated to test robustness and scalability. Results show that the system is able to outperform state-of-the-art knowledge-based systems, obtaining more than 10% of accuracy improvement in some cases, while only requiring minimal external resources. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Antibiotic contamination in a typical developing city in south China: occurrence and ecological risks in the Yongjiang River impacted by tributary discharge and anthropogenic activities.

    Science.gov (United States)

    Xue, Baoming; Zhang, Ruijie; Wang, Yinghui; Liu, Xiang; Li, Jun; Zhang, Gan

    2013-06-01

    The occurrence and distribution of ten selected antibiotics from three groups (sulfonamides, macrolides, and trimethoprim) were investigated in the Yongjiang River, which flows through Nanning City, a typical developing city in China. The study also assessed the ecological risks and the potential effects caused by discharge from tributaries and anthropogenic activities. Concentrations of most of the antibiotics were elevated along the section of the river in the urban area, highlighting the significant impact of high population density and human activities on the presence of antibiotics in the environment. The concentrations in the tributaries (ranged from not detected to 1336ngL(-1)) were generally higher than those in the main stream (ranged from not detected to 78.8ngL(-1)), but both areas contained the same predominant antibiotics, revealing the importance of tributary discharge as a source of antibiotic pollution. A risk assessment for the surface water contamination revealed that sulfamethoxazole and erythromycin posed high ecological risks to the most sensitive aquatic organisms (Synechococcus leopoliensis and Pseudokirchneriella subcapitata, respectively) in the midstream and some tributaries. Most of the selected antibiotics presented high ecological risks (risk quotients up to 95) in the sediments. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Evolutionary Ecology of Multitrophic Interactions between Plants, Insect Herbivores and Entomopathogens.

    Science.gov (United States)

    Shikano, Ikkei

    2017-06-01

    Plants play an important role in the interactions between insect herbivores and their pathogens. Since the seminal review by Cory and Hoover (2006) on plant-mediated effects on insect-pathogen interactions, considerable progress has been made in understanding the complexity of these tritrophic interactions. Increasing interest in the areas of nutritional and ecological immunology over the last decade have revealed that plant primary and secondary metabolites can influence the outcomes of insect-pathogen interactions by altering insect immune functioning and physical barriers to pathogen entry. Some insects use plant secondary chemicals and nutrients to prevent infections (prophylactic medication) and medicate to limit the severity of infections (therapeutic medication). Recent findings suggest that there may be selectable plant traits that enhance entomopathogen efficacy, suggesting that entomopathogens could potentially impose selection pressure on plant traits that improve both pathogen and plant fitness. Moreover, plants in nature are inhabited by diverse communities of microbes, in addition to entomopathogens, some of which can trigger immune responses in insect herbivores. Plants are also shared by numerous other herbivorous arthropods with different modes of feeding that can trigger different defensive responses in plants. Some insect symbionts and gut microbes can degrade ingested defensive phytochemicals and be orally secreted onto wounded plant tissue during herbivory to alter plant defenses. Since non-entomopathogenic microbes and other arthropods are likely to influence the outcomes of plant-insect-entomopathogen interactions, I discuss a need to consider these multitrophic interactions within the greater web of species interactions.

  19. CyanoHAB Occurrence and Water Irrigation Cyanotoxin Contamination: Ecological Impacts and Potential Health Risks

    Science.gov (United States)

    Saqrane, Sana; Oudra, Brahim

    2009-01-01

    The world-wide occurrence of harmful cyanobacteria blooms “CyanoHAB” in fresh and brackish waters creates problems for all life forms. During CyanoHAB events, toxic cyanobacteria produce cyanotoxins at high levels that can cause chronic and sub-chronic toxicities to animals, plants and humans. Cyanotoxicity in eukaryotes has been mainly focused on animals, but during these last years, data, related to cyanotoxin (mainly microcystins, MCs) impact on both aquatic and terrestrials crop plants irrigated by water containing these toxins, have become more and more available. This last cited fact is gaining importance since plants could in a direct or indirect manner contribute to cyanotoxin transfer through the food chain, and thus constitute a potent health risk source. The use of this contaminated irrigation water can also have an economical impact which appears by a reduction of the germination rate of seeds, and alteration of the quality and the productivity of crop plants. The main objective of this work was to discuss the eventual phytotoxicity of cyanotoxins (microcystins) as the major agricultural impacts induced by the use of contaminated water for plant irrigation. These investigations confirm the harmful effects (ecological, eco-physiological, socio-economical and sanitary risk) of dissolved MCs on agricultural plants. Thus, cyanotoxin phytotoxicity strongly suggests a need for the surveillance of CyanoHAB and the monitoring of water irrigation quality as well as for drinking water. PMID:22069535

  20. Establishing Baseline Key Ecological Functions of Fish and Wildlife for Subbasin Planning, Final Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

    O' Neil, Thomas A.

    2001-08-01

    As we strive to manage the Columbia River Basin for its sustainable, productive, and diverse ecosystems, we are, in fact, managing these systems to provide an a array of ecological functions upon which these systems are based. These ecological functions avail themselves as an important tool with which to assess our historical and current habitat conditions, as well as proposed future or ideal conditions under differing management scenarios. So what are key ecological functions (KEFs) and which ones are involved? Key ecological functions refer to the major ecological roles played by an organism in its ecosystem that can affect environmental conditions for themselves or other species, or that directly influences other organisms (Marcot and Vander Heyden 2001). Currently, 111 KEFs are identified for fish and wildlife species as a result of Task 1 of this project. Even though the assessment phase of this project encompasses the entire Columbia River Basin, only a subset of KEFs (58) that are associated with the lotic systems, which includes 7 anadromous fish, 20 co-occurring resident fish, and 137 wildlife species linked to salmon are addressed. Since the basin has not be systematically surveyed for each fish and wildlife species, baseline conditions for each KEF are determined by developing basin-wide species range maps using the following information: wildlife-habitat type associations, county and ecoprovince occurrence, literature (like individual state atlases), and expert peer review. This approach produced a set of species range maps that depict a species potential for occurrence given the current or historic conditions. It is this potential occurrence that serves as a baseline condition to determine the key ecological functions. The results offer a framework and a set of baseline assessments that can be done with existing databases. Thus, allowing resource managers the ability to assess future management activities against this norm and guide their activities in

  1. Chemical ecology of the marine plankton.

    Science.gov (United States)

    Roy, Jessie S; Poulson-Ellestad, Kelsey L; Drew Sieg, R; Poulin, Remington X; Kubanek, Julia

    2013-10-11

    This review summarizes recent work in the chemical ecology of pelagic marine ecosystems. In order to provide a comprehensive overview of advances in the field over the period covered, we have organized this review by ecological interaction type beginning with intraspecific interactions, then interspecific interactions (including mutualism, parasitism, competition, and predation), and finally community- and ecosystem-wide interactions.

  2. Estimating negative binomial parameters from occurrence data with detection times.

    Science.gov (United States)

    Hwang, Wen-Han; Huggins, Richard; Stoklosa, Jakub

    2016-11-01

    The negative binomial distribution is a common model for the analysis of count data in biology and ecology. In many applications, we may not observe the complete frequency count in a quadrat but only that a species occurred in the quadrat. If only occurrence data are available then the two parameters of the negative binomial distribution, the aggregation index and the mean, are not identifiable. This can be overcome by data augmentation or through modeling the dependence between quadrat occupancies. Here, we propose to record the (first) detection time while collecting occurrence data in a quadrat. We show that under what we call proportionate sampling, where the time to survey a region is proportional to the area of the region, that both negative binomial parameters are estimable. When the mean parameter is larger than two, our proposed approach is more efficient than the data augmentation method developed by Solow and Smith (, Am. Nat. 176, 96-98), and in general is cheaper to conduct. We also investigate the effect of misidentification when collecting negative binomially distributed data, and conclude that, in general, the effect can be simply adjusted for provided that the mean and variance of misidentification probabilities are known. The results are demonstrated in a simulation study and illustrated in several real examples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Simultaneous assessments of occurrence, ecological, human health, and organoleptic hazards for 77 VOCs in typical drinking water sources from 5 major river basins, China.

    Science.gov (United States)

    Chen, Xichao; Luo, Qian; Wang, Donghong; Gao, Jijun; Wei, Zi; Wang, Zijian; Zhou, Huaidong; Mazumder, Asit

    2015-11-01

    Owing to the growing public awareness on the safety and aesthetics in water sources, more attention has been given to the adverse effects of volatile organic compounds (VOCs) on aquatic organisms and human beings. In this study, 77 target VOCs (including 54 common VOCs, 13 carbonyl compounds, and 10 taste and odor compounds) were detected in typical drinking water sources from 5 major river basins (the Yangtze, the Huaihe, the Yellow, the Haihe and the Liaohe River basins) and their occurrences were characterized. The ecological, human health, and olfactory assessments were performed to assess the major hazards in source water. The investigation showed that there existed potential ecological risks (1.30 × 10 ≤ RQtotals ≤ 8.99 × 10) but little human health risks (6.84 × 10(-7) ≤ RQtotals ≤ 4.24 × 10(-4)) by VOCs, while that odor problems occurred extensively. The priority contaminants in drinking water sources of China were also listed based on the present assessment criteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Rivers are social–ecological systems: Time to integrate human dimensions into riverscape ecology and management

    Science.gov (United States)

    Dunham, Jason B.; Angermeier, Paul L.; Crausbay, Shelley D.; Cravens, Amanda; Gosnell, Hannah; McEvoy, Jamie; Moritz, Max A.; Raheem, Nejem; Sanford, Todd

    2018-01-01

    Incorporation of concepts from landscape ecology into understanding and managing riverine ecosystems has become widely known as riverscape ecology. Riverscape ecology emphasizes interactions among processes at different scales and their consequences for valued ecosystem components, such as riverine fishes. Past studies have focused strongly on understanding the ecological processes in riverscapes and how human actions modify those processes. It is increasingly clear, however, that an understanding of the drivers behind actions that lead to human modification also merit consideration, especially regarding how those drivers influence management efficacy. These indirect drivers of riverscape outcomes can be understood in the context of a diverse array of social processes, which we collectively refer to as human dimensions. Like ecological phenomena, social processes also exhibit complex interactions across spatiotemporal scales. Greater emphasis on feedbacks between social and ecological processes will lead scientists and managers to more completely understand riverscapes as complex, dynamic, interacting social–ecological systems. Emerging applications in riverscapes, as well as studies of other ecosystems, provide examples that can lead to stronger integration of social and ecological science. We argue that conservation successes within riverscapes may not come from better ecological science, improved ecosystem service analyses, or even economic incentives if the fundamental drivers of human behaviors are not understood and addressed in conservation planning and implementation.

  5. Evolution of nutrient uptake reveals a trade-off in the ecological stoichiometry of plant-herbivore interactions

    NARCIS (Netherlands)

    Branco, P.; Stomp, M.; Egas, M.; Huisman, J.

    2010-01-01

    Nutrient limitation determines the primary production and species composition of many ecosystems. Here we apply an adaptive dynamics approach to investigate evolution of the ecological stoichiometry of primary producers and its implications for plant‐herbivore interactions. The model predicts a

  6. Age differences in adults' daily social interactions: An ecological momentary assessment study.

    Science.gov (United States)

    Zhaoyang, Ruixue; Sliwinski, Martin J; Martire, Lynn M; Smyth, Joshua M

    2018-04-30

    Prevailing research has suggested that social relationships get better with age, but this evidence has been largely based on studies with lengthy reporting intervals. Using an ecological momentary assessment approach, the present study examined age differences in several characteristics of social interactions as reported in near-real time: the frequency, quality, and partner type. Participants (N = 173) ages 20-79 years reported their social interactions at 5 random times throughout the day for 1 week. Results revealed that age was associated with higher frequency of interacting with family and lower frequency of interacting with peripheral partners. These age effects, however, became nonsignificant after accounting for contextual factors such as race, gender, education, employment status, family structure, and living arrangement. In contrast, a curvilinear relationship best characterized age differences in both positive and negative ratings of daily social interaction quality, with middle-aged adults reporting the lowest positive ratings and older adults reporting the lowest negative ratings among all ages. Contextual factors did not account for these patterns of age differences in interaction quality. Furthermore, the intraindividual variability of interaction frequency with peripheral partners, partner diversity, and interaction quality (positivity and negativity) was lower among older adults than among younger adults. Findings from the present study portray a nuanced picture of social interactions in daily life and advance the understanding of social interactions across the life span. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  7. Gender-biased perceptions of important ecology articles

    OpenAIRE

    Courchamp, Franck; Bradshaw, Corey

    2017-01-01

    Gender bias is still unfortunately rife in the sciences, and men co-author most articles (> 70%) in ecology. Whether ecologists subconsciously rate the quality of their peers' work more favourably if men are the dominant co-authors is still unclear. To test this hypothesis, we examined how expert ecologists ranked important ecology articles based on a previously compiled list. Women proposed articles with a higher average proportion of women co-authors (0.18) than did men proposers (0.07)....

  8. Ecological palaeoecology: a missing link between ecology and evolution

    Directory of Open Access Journals (Sweden)

    Rull, V.

    2014-12-01

    Full Text Available Palaeoecology is more than a palaeoenvironmental discipline; it is a science that is well-suited for supplying the empirical evidence necessary to test ecological hypotheses and contributes to our understanding of the interface of ecology and evolution. A critical time frame in palaeoecology is the often-overlooked Q-time dimension (centuries to millennia, which tends to be the most appropriate time dimension to examine ecology–evolution interactions. This paper discusses these topics from a conceptual perspective and provides examples of the contributions of palaeoecology to the study of ecology–evolution interactions. It also admonishes researchers about the threats of overlooking palaeoecology. Specifically, this paper argues that the neglect of palaeoecology may result in the loss of empirical support for ecology and its interactions with evolution as DNA-based phylogenetic and phylogeographic studies become more and more prevalent. The main concepts discussed are the time continuum, the notion of ecological palaeoecology and the empirical nature of palaeoecology in the face of more hypothetical approaches. More practically speaking, several examples are provided that highlight the utility of ecological palaeoecology for understanding a variety of processes, including ecological succession, community– environment equilibria, community assembly, biotic responses to environmental change, speciation and extinction, and biodiversity conservation. The ecology–evolution interface is analysed using two processes in which these disciplines interact intensively: ecological succession and long-range migration. This work concludes that both ecological palaeoecology (including ancient DNA records and DNA-based phylogenetics and phylogeography are needed to better understand the biosphere ecologically and the processes occurring at the ecology–evolution interface.La paleoecología es más que una disciplina ambiental, ya que proporciona las

  9. Ecological Controls on Land-Atmosphere Exchange

    Science.gov (United States)

    Goulden, M. L.; Litvak, M. E.; Winston, G.; Miller, S. D.; Read, E.; Elliot, R.

    2002-12-01

    We have been using long-term eddy covariance to investigate the patterns of energy and CO2 exchange between the atmosphere and a freshwater marsh in California, and also between the atmosphere and a series of boreal forest stands in Manitoba, Canada. Most researchers believe that ecological phenomenon, such as plant herbivore interactions and interspecific differences in plant life-history strategy, are relatively unimportant in determining the interannual and landscape patterns of Land-Atmosphere exchange. However, we have found that interactions between plants and herbivores exert a large control on the interannual patterns of energy and CO2 exchange in the freshwater marsh, and that interspecific differences in plant strategy are critical for understanding the landscape scale patterns of energy and CO2 exchange in the boreal forest. Despite a relatively constant climate and flooding regime at the California marsh, annual Carbon balance varied by 6 tC ha-1 or more from year to year. These deviations were caused in part by variation in herbivory by rodents and insects. Likewise, peak CO2 uptake by boreal forest stands recovering from fire differed less than expected, with a 4-year-old stand assimilating CO2 at rates comparable to that by middle aged stands, and faster than that by old stands. These patterns reflect differences in the life history strategies of the dominant plants, with the youngest stands dominated by fast growing ruderals, the middle aged stands dominated by fast growing competitive species, and the old stands dominated by slow growing stress tolerant species.

  10. A Combination of Stable Isotope Probing, Illumina Sequencing, and Co-occurrence Network to Investigate Thermophilic Acetate- and Lactate-Utilizing Bacteria.

    Science.gov (United States)

    Sun, Weimin; Krumins, Valdis; Dong, Yiran; Gao, Pin; Ma, Chunyan; Hu, Min; Li, Baoqin; Xia, Bingqing; He, Zijun; Xiong, Shangling

    2018-01-01

    Anaerobic digestion is a complicated microbiological process that involves a wide diversity of microorganisms. Acetate is one of the most important intermediates, and interactions between acetate-oxidizing bacteria and archaea could play an important role in the formation of methane in anoxic environments. Anaerobic digestion at thermophilic temperatures is known to increase methane production, but the effects on the microbial community are largely unknown. In the current study, stable isotope probing was used to characterize acetate- and lactate-oxidizing bacteria in thermophilic anaerobic digestion. In microcosms fed 13 C-acetate, bacteria related to members of Clostridium, Hydrogenophaga, Fervidobacterium, Spirochaeta, Limnohabitans, and Rhodococcus demonstrated elevated abundances of 13 C-DNA fractions, suggesting their activities in acetate oxidation. In the treatments fed 13 C-lactate, Anaeromyxobacter, Desulfobulbus, Syntrophus, Cystobacterineae, and Azospira were found to be the potential thermophilic lactate utilizers. PICRUSt predicted that enzymes related to nitrate and nitrite reduction would be enriched in 13 C-DNA fractions, suggesting that the acetate and lactate oxidation may be coupled with nitrate and/or nitrite reduction. Co-occurrence network analysis indicated bacterial taxa not enriched in 13 C-DNA fractions that may also play a critical role in thermophilic anaerobic digestion.

  11. Using a social-ecological systems perspective to understand tourism and landscape interactions in coastal areas

    Directory of Open Access Journals (Sweden)

    Jasper Hessel Heslinga

    2017-04-01

    Full Text Available Purpose – The purpose of this paper is to look at the potential synergies between tourism and landscapes and examine the potential contribution of tourism to build social-ecological resilience in the Dutch Wadden. Design/methodology/approach – The authors reveal how a social-ecological systems perspective can be used to conceptualize the Wadden as a coupled and dynamic system. This paper is a conceptual analysis that applies this approach to the Dutch Wadden. The data used for the inquiry primarily comes from a literature review. Findings – The authors argue that the social-ecological systems perspective is a useful approach and could be used to improve the governance of multi-functional socio-ecological systems in coastal areas. Opportunities for synergies between tourism and landscapes have been overlooked. The authors consider that tourism and nature protection are potentially compatible and that the synergies should be identified. Research limitations/implications – This paper is only a conceptual application rather than an empirical case study. Further research to actually apply the methodology is needed. Practical implications – Managers of protected areas should consider applying a social-ecological systems approach. Social implications – The views of a wide variety of stakeholders should be considered in landscape planning. Originality/value – The value of this paper lies in the articulation of the social-ecological systems perspective as a way to identify and understand the complex interactions between tourism and landscape, and the potential synergies between them.

  12. Ecologically Sound Procedural Generation of Natural Environments

    Directory of Open Access Journals (Sweden)

    Benny Onrust

    2017-01-01

    Full Text Available Current techniques for the creation and exploration of virtual worlds are largely unable to generate sound natural environments from ecological data and to provide interactive web-based visualizations of such detailed environments. We tackle this challenge and propose a novel framework that (i explores the advantages of landscape maps and ecological statistical data, translating them to an ecologically sound plant distribution, and (ii creates a visually convincing 3D representation of the natural environment suitable for its interactive visualization over the web. Our vegetation model improves techniques from procedural ecosystem generation and neutral landscape modeling. It is able to generate diverse ecological sound plant distributions directly from landscape maps with statistical ecological data. Our visualization model integrates existing level of detail and illumination techniques to achieve interactive frame rates and improve realism. We validated with ecology experts the outcome of our framework using two case studies and concluded that it provides convincing interactive visualizations of large natural environments.

  13. Full Data of Yeast Interacting Proteins Database (Annotation Updated Version) - Yeast Interacting Proteins Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available As the indicator of reliability of the interactions obtained by the experiment, the literature...cids Res. 28, 73-76.) are used for literature collection. Number of data entries ...ber of articles obtained from the YPD. Literature sharing score The score concerning co-occurrence of Prey and Bait in the literature

  14. Mycotoxin occurrence on baled and pit silages collected in Co. Meath

    Directory of Open Access Journals (Sweden)

    McElhinney C.

    2015-12-01

    Full Text Available Recent studies of baled silages produced in Ireland have identified considerable filamentous fungal contamination. Many of these fungi are toxigenic, capable of producing secondary metabolites, namely mycotoxins. Mycotoxins are potentially detrimental to livestock health and some can pose a risk to consumers of animal products. Baled (n=20 and pit (n=18 silages from a sample of farms (n=38 in Co. Meath were examined to assess the occurrence of mycotoxins and ascertain whether sampling position within the pit silos (feed face vs. 3 m behind the feed face has an effect on mycotoxin content or other chemical compositional variables. Of the 20 mycotoxins assayed, baled silages contained [mean of positive values (no. of values in mean] mycotoxin concentrations (μg/kg dry matter of beauvericin 36 (2, enniatin (enn. A 9.3 (3, enn. A1 54 (8, enn. B 351 (9, enn. B1 136 (10, mycophenolic acid (MPA 11,157 (8 and roquefortine C (Roq. C 1037 (8 and pit silages contained beauvericin 25 (2 enn. A1 18 (2, enn. B 194 (9, enn. B1 57 (3, MPA 287 (6, Roq. C 3649 (6 and zearalenone 76 (1. There was no difference (P>0.05 observed in the mycotoxin concentrations between baled and pit silages, and 11 of the 20 mycotoxins assayed were below the limits of detection. The position of sampling had no effect on the mycotoxin concentration detected in pit silages. It is concluded that mycotoxin concentrations detected in these pit and baled silages in Co. Meath did not exceed EU regulation or guidance limits, and that similar chemical composition and mycotoxin concentration values occurred at the pit silage feed face and 3 m behind this feed face.

  15. Coupled X-ray computed tomography and grey level co-occurrence matrices as a method for quantification of mineralogy and texture in 3D

    Science.gov (United States)

    Jardine, M. A.; Miller, J. A.; Becker, M.

    2018-02-01

    Texture is one of the most basic descriptors used in the geological sciences. The value derived from textural characterisation extends into engineering applications associated with mining, mineral processing and metal extraction where quantitative textural information is required for models predicting the response of the ore through a particular process. This study extends the well-known 2D grey level co-occurrence matrices methodology into 3D as a method for image analysis of 3D x-ray computed tomography grey scale volumes of drill core. Subsequent interrogation of the information embedded within the grey level occurrence matrices (GLCM) indicates they are sensitive to changes in mineralogy and texture of samples derived from a magmatic nickel sulfide ore. The position of the peaks in the GLCM is an indication of the relative density (specific gravity, SG) of the minerals and when interpreted using a working knowledge of the mineralogy of the ore presented a means to determine the relative abundance of the sulfide minerals (SG > 4), dense silicate minerals (SG > 3), and lighter silicate minerals (SG < 3). The spread of the peaks in the GLCM away from the diagonal is an indication of the degree of grain boundary interaction with wide peaks representing fine grain sizes and narrow peaks representing coarse grain sizes. The method lends itself to application as part of a generic methodology for routine use on large XCT volumes providing quantitative, timely, meaningful and automated information on mineralogy and texture in 3D.

  16. Ecological Momentary Assessment of social functioning in schizophrenia: impact of performance appraisals and affect on social interactions.

    Science.gov (United States)

    Granholm, Eric; Ben-Zeev, Dror; Fulford, Daniel; Swendsen, Joel

    2013-04-01

    Research concerning the complex interplay between factors that contribute to poor social functioning in schizophrenia has been hampered by limitations of traditional measures, most notably the ecological validity and accuracy of retrospective self-report and interview measures. Computerized Ecological Momentary Assessment (EMAc) permits the real-time assessment of relationships between daily life experiences, thoughts, feelings, and behaviors. In the current study, EMAc was used to record daily social interactions, subjective performance appraisals of these interactions (e.g., "I succeeded/failed"; "I was liked/rejected"), and affect in 145 individuals with schizophrenia or schizoaffective disorder. Participants completed electronic questionnaires on a personal digital assistant (PDA) four times per day for one week. Time-lagged multilevel modeling of the data revealed that more positive interaction appraisals at any point in a day were associated with greater positive affect which, in turn, was a strong predictor of more social interactions over subsequent hours. Social functioning, therefore, was linked to positive performance beliefs about social interactions that were associated with greater positive affect. The findings suggest a useful treatment target for cognitive behavioral therapy and other psychosocial interventions that can be used to challenge defeatist beliefs and increase positive affect to enhance social functioning in schizophrenia. Published by Elsevier B.V.

  17. Ecologic Niche Modeling of Blastomyces dermatitidis in Wisconsin

    Science.gov (United States)

    Reed, Kurt D.; Meece, Jennifer K.; Archer, John R.; Peterson, A. Townsend

    2008-01-01

    Background Blastomycosis is a potentially fatal mycosis that is acquired by inhaling infectious spores of Blastomyces dermatitidis present in the environment. The ecology of this pathogen is poorly understood, in part because it has been extremely difficult to identify the niche(s) it occupies based on culture isolation of the organism from environmental samples. Methodology/Principal Findings We investigated the ecology of blastomycosis by performing maximum entropy modeling of exposure sites from 156 cases of human and canine blastomycosis to provide a regional-scale perspective of the geographic and ecologic distribution of B. dermatitidis in Wisconsin. Based on analysis with climatic, topographic, surface reflectance and other environmental variables, we predicted that ecologic conditions favorable for maintaining the fungus in nature occur predominantly within northern counties and counties along the western shoreline of Lake Michigan. Areas of highest predicted occurrence were often in proximity to waterways, especially in northcentral Wisconsin, where incidence of infection is highest. Ecologic conditions suitable for B. dermatitidis are present in urban and rural environments, and may differ at the extremes of distribution of the species in the state. Conclusions/Significance Our results provide a framework for a more informed search for specific environmental factors modulating B. dermatitidis occurrence and transmission and will be useful for improving public health awareness of relative exposure risks. PMID:18446224

  18. 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.

  19. The Co-occurrence of Gambling with Substance Use and Conduct Disorder among Youth in the U.S

    Science.gov (United States)

    Barnes, Grace M.; Welte, John W.; Hoffman, Joseph H.; Tidwell, Marie-Cecile O.

    2013-01-01

    The co-occurrence of gambling with substance use and conduct disorder was examined in a representative U.S. household sample of 2,274 youth 14 to 21 years old. The findings show that problem gambling occurs within a problem behavior syndrome with other substance use behaviors and conduct disorder. Male gender, being black, and being Hispanic were found to be significant in predicting problem gambling over and above the effects of all four substance use and conduct disorder variables. Clinical interventions for one specific problem behavior in youth should consider assessing the other problem behaviors as well. PMID:21314760

  20. Combining Science and Traditional Ecological Knowledge: Monitoring Populations for Co-Management

    Directory of Open Access Journals (Sweden)

    Henrik Moller

    2004-12-01

    Full Text Available Using a combination of traditional ecological knowledge and science to monitor populations can greatly assist co-management for sustainable customary wildlife harvests by indigenous peoples. Case studies from Canada and New Zealand emphasize that, although traditional monitoring methods may often be imprecise and qualitative, they are nevertheless valuable because they are based on observations over long time periods, incorporate large sample sizes, are inexpensive, invite the participation of harvesters as researchers, and sometimes incorporate subtle multivariate cross checks for environmental change. A few simple rules suggested by traditional knowledge may produce good management outcomes consistent with fuzzy logic thinking. Science can sometimes offer better tests of potential causes of population change by research on larger spatial scales, precise quantification, and evaluation of population change where no harvest occurs. However, science is expensive and may not always be trusted or welcomed by customary users of wildlife. Short scientific studies in which traditional monitoring methods are calibrated against population abundance could make it possible to mesh traditional ecological knowledge with scientific inferences of prey population dynamics. This paper analyzes the traditional monitoring techniques of catch per unit effort and body condition. Combining scientific and traditional monitoring methods can not only build partnership and community consensus, but also, and more importantly, allow indigenous wildlife users to critically evaluate scientific predictions on their own terms and test sustainability using their own forms of adaptive management.

  1. Establishing baseline key ecological functions of fish and wildlife for subbasin planning, final report 2001.; FINAL

    International Nuclear Information System (INIS)

    O'Neil, Thomas A.

    2001-01-01

    As we strive to manage the Columbia River Basin for its sustainable, productive, and diverse ecosystems, we are, in fact, managing these systems to provide an a array of ecological functions upon which these systems are based. These ecological functions avail themselves as an important tool with which to assess our historical and current habitat conditions, as well as proposed future or ideal conditions under differing management scenarios. So what are key ecological functions (KEFs) and which ones are involved? Key ecological functions refer to the major ecological roles played by an organism in its ecosystem that can affect environmental conditions for themselves or other species, or that directly influences other organisms (Marcot and Vander Heyden 2001). Currently, 111 KEFs are identified for fish and wildlife species as a result of Task 1 of this project. Even though the assessment phase of this project encompasses the entire Columbia River Basin, only a subset of KEFs (58) that are associated with the lotic systems, which includes 7 anadromous fish, 20 co-occurring resident fish, and 137 wildlife species linked to salmon are addressed. Since the basin has not be systematically surveyed for each fish and wildlife species, baseline conditions for each KEF are determined by developing basin-wide species range maps using the following information: wildlife-habitat type associations, county and ecoprovince occurrence, literature (like individual state atlases), and expert peer review. This approach produced a set of species range maps that depict a species potential for occurrence given the current or historic conditions. It is this potential occurrence that serves as a baseline condition to determine the key ecological functions. The results offer a framework and a set of baseline assessments that can be done with existing databases. Thus, allowing resource managers the ability to assess future management activities against this norm and guide their activities in

  2. Frugivores and seed dispersal: mechanisms and consequences for biodiversity of a key ecological interaction.

    Science.gov (United States)

    Jordano, Pedro; Forget, Pierre-Michel; Lambert, Joanna E; Böhning-Gaese, Katrin; Traveset, Anna; Wright, S Joseph

    2011-06-23

    The 5th Symposium on Frugivores and Seed Dispersal, held in Montpellier (France), 13-18 June 2010, brought together more than 220 researchers exemplifying a wide diversity of approaches to the study of frugivory and dispersal of seeds. Following Ted Fleming and Alejandro Estrada's initiative in 1985, this event was a celebration of the 25th anniversary of the first meeting in Veracruz, Mexico. Frugivory and seed dispersal are active research areas that have diversified in multiple directions since 1985 to include evolution (e.g. phylogenetic diversity and dispersal adaptations), physiology (e.g. sensory cues and digestion), landscape ecology (movement patterns), molecular ecology (e.g. gene flow, genetic diversity and structure), community ecology (e.g. mutualistic interaction networks) and conservation biology (effects of hunting, fragmentation, invasion and extinction), among others. This meeting provided an opportunity to assess conceptual and methodological progress, to present ever more sophisticated insights into frugivory in animals and dispersal patterns in plants, and to report the advances made in examining the mechanisms and consequences of seed dispersal for plants and frugivores.

  3. Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly

    Science.gov (United States)

    Yılmaz, Tevfik; Turan, Yahya; Gülşen, İsmail; Dalbayrak, Sedat

    2014-01-01

    Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury. PMID:25210343

  4. Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly

    Directory of Open Access Journals (Sweden)

    Tevfik Yilmaz

    2014-01-01

    Full Text Available Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury.

  5. Eligibility for interventions, co-occurrence and risk factors for unhealthy behaviours in patients consulting for routine primary care: results from the Pre-Empt study

    OpenAIRE

    Randell, Elizabeth; Pickles, Timothy; Simpson, Sharon A.; Spanou, Clio; McCambridge, Jim; Hood, Kerenza; Butler, Christopher C.

    2015-01-01

    Background:\\ud Smoking, excessive drinking, lack of exercise and a poor diet remain key causes of premature morbidity and mortality globally, yet it is not clear what proportion of patients attending for routine primary care are eligible for interventions about these behaviours, the extent to which they co-occur within individuals, and which individuals are at greatest risk for multiple unhealthy behaviours. The aim of the trial was to examine ‘intervention eligibility’ and co-occurrence of t...

  6. Stopover ecology of neotropical migrants in central Veracruz, México

    Science.gov (United States)

    Ernesto Ruelas Inzunza; Stephen W. Hoffman; Laurie J. Goodrich

    2005-01-01

    Available information on the ecology of neotropical migrants during the winter season and especially during migration is far behind the existing knowledge of birds during the breeding season. This paper presents a stopover ecology case study. We document the occurrence of species, outline the prevailing weather patterns during spring and fall migration seasons, and...

  7. Manual for prototyping integrated and ecological arable farming systems (I/EAFS) in interaction with pilot farms

    NARCIS (Netherlands)

    Vereijken, P.

    1999-01-01

    A manual for prototyping Integrated and Ecological Arable Farming Systems (I/EAFS) in interaction with pilot farms is presented. It concerns a comprehensive and consistent approach of 5 steps. Step 1 is establishing a hierarchy of objectives considering the shortcomings of current farming systems in

  8. Species interactions and the effects of climate variability on a wetland amphibian metacommunity

    Science.gov (United States)

    Davis, Courtney L.; Miller, David A.W.; Walls, Susan C.; Barichivich, William J.; Riley, Jeffrey W.; Brown, Mary E.

    2017-01-01

    Disentangling the role that multiple interacting factors have on species responses to shifting climate poses a significant challenge. However, our ability to do so is of utmost importance to predict the effects of climate change on species distributions. We examined how populations of three species of wetland-breeding amphibians, which varied in life history requirements, responded to a six-year period of extremely variable precipitation. This interval was punctuated by both extensive drought and heavy precipitation and flooding, providing a natural experiment to measure community responses to environmental perturbations. We estimated occurrence dynamics using a discrete hidden Markov modeling approach that incorporated information regarding habitat state and predator–prey interactions. This approach allowed us to measure how metapopulation dynamics of each amphibian species was affected by interactions among weather, wetland hydroperiod, and co-occurrence with fish predators. The pig frog, a generalist, proved most resistant to perturbations, with both colonization and persistence being unaffected by seasonal variation in precipitation or co-occurrence with fishes. The ornate chorus frog, an ephemeral wetland specialist, responded positively to periods of drought owing to increased persistence and colonization rates during periods of low-rainfall. Low probabilities of occurrence of the ornate chorus frog in long-duration wetlands were driven by interactions with predators due to low colonization rates when fishes were present. The mole salamander was most sensitive to shifts in water availability. In our study area, this species never occurred in short-duration wetlands and persistence probabilities decreased during periods of drought. At the same time, negative effects occurred with extreme precipitation because flooding facilitated colonization of fishes to isolated wetlands and mole salamanders did not colonize wetlands once fishes were present. We

  9. The Narssaq-project - a geochemical, ecological environmental research project

    International Nuclear Information System (INIS)

    Soerensen, H.; Rose-Hansen, J.

    1978-01-01

    Two types of mineral occurrences near the town of Narssaq in South Greenland are recorded to be worth mining in the near future: the uranium occurrences at Kvanefjeld in the northern part of the Ilimaussaq intrusion and the zirconium occurrences in the southern part on the south coast of the Kangerdluarssuk fjord. Consideration of the environment plays a large part in discussions regarding the exploitation of these minerals. A report is given of the geochemical, ecological environmental investigations carried out at Narssaq since 1974. (BP)

  10. Divergent Responses of the Diazotrophic Microbiome to Elevated CO2 in Two Rice Cultivars

    Directory of Open Access Journals (Sweden)

    Yongjie Yu

    2018-06-01

    Full Text Available The species-specific responses of plant growth to elevated atmospheric CO2 concentration (eCO2 could lead to N limitation and potentially influence the sustainability of ecosystem. Questions remain unanswered with regards to the response of soil N2-fixing community to eCO2 when developing high-yielding agroecosystem to dampen the future rate of increase in CO2 levels and associated climate warming. This study demonstrates the divergent eCO2 influences on the paddy diazotrophic community between weak- and strong-responsive rice cultivars. In response to eCO2, the diazotrophic abundance increased more for the strong-responsive cultivar treatments than for the weak-responsive ones. Only the strong-responsive cultivars decreased the alpha diversity and separated the composition of diazotrophic communities in response to eCO2. The topological indices of the ecological networks further highlighted the different co-occurrence patterns of the diazotrophic microbiome in rice cultivars under eCO2. Strong-responsive cultivars destabilized the diazotrophic community by complicating and centralizing the co-occurrence network as well as by shifting the hub species from Bradyrhizobium to Dechloromonas in response to eCO2. On the contrary, the network pattern of the weak-responsive cultivars was simplified and decentralized in response to eCO2, with the hub species shifting from Halorhodospira under aCO2 to Sideroxydans under eCO2. Collectively, the above information indicates that the strong-responsive cultivars could potentially undermine the belowground ecosystem from the diazotrophs perspective in response to eCO2. This information highlights that more attention should be paid to the stability of the belowground ecosystem when developing agricultural strategies to adapt prospective climatic scenarios by growing high-yielding crop cultivars under eCO2.

  11. 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.

  12. Investigation into interaction of CO/sub 2/ molecules with zeolites by infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ignat' eva, L A; Levshin, L V; Chukin, G D; Efimenko, L V; Kozlova, T I [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Optiki

    1975-07-01

    Interaction of CO/sub 2/ molecules with zeolites, particularly with SrNaJ was studied by infrared-spectroscopy. To obtain infrared-spectra the zeolites were pressed into tablets and were calcinated at 500 deg. In the spectra the bands of chemisorbed CO/sub 2/ absorption were found in the range 1300 - 1600 cm/sup -1/. The CO/sub 2/ molecule was found to be strongly deformed due to chemisorption. In terms of electronic structure of the zeolite crystalline skeleton several types of CO/sub 2/ molecules interaction with different active zeolites were found. The position of the high-frequency band of CO/sub 2/ absorption in zeolites spectra was found to be a linear function of electrostatic field of the cations.

  13. Priorities for research in soil ecology

    NARCIS (Netherlands)

    Eisenhauer, N.; Antunes, P.M.; Bennett, A.E.; Birkhofer, K.; Bisset, A.; Bowker, M.A.; T., Caruso; B., Chen; Coleman, D.C.; W., De Boer; van Straalen, N.M.

    2017-01-01

    The ecological interactions that occur in and with soil are of consequence in many ecosystems on the planet. These interactions provide numerous essential ecosystem services, and the sustainable management of soils has attracted increasing scientific and public attention. Although soil ecology

  14. Restoration of Bi-Contrast MRI Data for Intensity Uniformity with Bayesian Coring of Co-Occurrence Statistics

    Directory of Open Access Journals (Sweden)

    Stathis Hadjidemetriou

    2017-12-01

    Full Text Available The reconstruction of MRI data assumes a uniform radio-frequency field. However, in practice, the radio-frequency field is inhomogeneous and leads to anatomically inconsequential intensity non-uniformities across an image. An anatomic region can be imaged with multiple contrasts reconstructed independently and be suffering from different non-uniformities. These artifacts can complicate the further automated analysis of the images. A method is presented for the joint intensity uniformity restoration of two such images. The effect of the intensity distortion on the auto-co-occurrence statistics of each image as well as on the joint-co-occurrence statistics of the two images is modeled and used for their non-stationary restoration followed by their back-projection to the images. Several constraints that ensure a stable restoration are also imposed. Moreover, the method considers the inevitable differences between the signal regions of the two images. The method has been evaluated extensively with BrainWeb phantom brain data as well as with brain anatomic data from the Human Connectome Project (HCP and with data of Parkinson’s disease patients. The performance of the proposed method has been compared with that of the N4ITK tool. The proposed method increases tissues contrast at least 4 . 62 times more than the N4ITK tool for the BrainWeb images. The dynamic range with the N4ITK method for the same images is increased by up to +29.77%, whereas, for the proposed method, it has a corresponding limited decrease of - 1 . 15 % , as expected. The validation has demonstrated the accuracy and stability of the proposed method and hence its ability to reduce the requirements for additional calibration scans.

  15. Case study of building of conservation coalitions to conserve ecological interactions.

    Science.gov (United States)

    Chen, Gao; Luo, Shihong; Mei, Nianshu; Shen, Dingfang; Sun, Weibang

    2015-12-01

    We engaged experts in various fields of study (pollination ecology, chemical ecology, and ethnobotany), invited community participation, and provided environmental education in an effort to conserve an endangered birthwort (Aristolochia delavayi) and a vulnerable pipevine swallowtail (Byasa daemonius). Scientists studied the uptake and sequestration of the secondary metabolites aristolochic acids from A. delavayi leaves by different stages of pipevine swallowtail as a defense mechanism; low fruit set of the myophilous A. delavayi due to pollinator limitation; and the emission of chemical signals that attract parasitic wasps by the prepupae of B. daemonius. The results of these studies were part of an education program delivered by personnel of non-governmental organizations. The program was devised to deliver information to the public about the health risks of consuming A. delavayi individuals (aristolochic-acid-associated cancers) and to establish a bridge between the public and scientific research. Following delivery of the program, the behavior of residents changed considerably. Community residents were involved in management activities, including participation in a program to promote understanding of ecological interactions between A. delavayi and B. daemonius; designing an in situ conservation site; monitoring A. delavayi and B. daemonius individuals; and promoting the natural fruit set of A. delavayi by scattering animal excrement to attract fly pollinators. The integration of scientific information and community participation appears to have resulted in an increase in abundance of threatened A. delavayi and B. daemonius populations. We believe the involvement of local people in conservation is necessary for successful species conservation. © 2015 Society for Conservation Biology.

  16. 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....

  17. Coprolites reveal ecological interactions lost with the extinction of New Zealand birds.

    Science.gov (United States)

    Boast, Alexander P; Weyrich, Laura S; Wood, Jamie R; Metcalf, Jessica L; Knight, Rob; Cooper, Alan

    2018-02-13

    Over the past 50,000 y, biotic extinctions and declines have left a legacy of vacant niches and broken ecological interactions across global terrestrial ecosystems. Reconstructing the natural, unmodified ecosystems that preceded these events relies on high-resolution analyses of paleoecological deposits. Coprolites are a source of uniquely detailed information about trophic interactions and the behaviors, gut parasite communities, and microbiotas of prehistoric animal species. Such insights are critical for understanding the legacy effects of extinctions on ecosystems, and can help guide contemporary conservation and ecosystem restoration efforts. Here we use high-throughput sequencing (HTS) of ancient eukaryotic DNA from coprolites to reconstruct aspects of the biology and ecology of four species of extinct moa and the critically endangered kakapo parrot from New Zealand (NZ). Importantly, we provide evidence that moa and prehistoric kakapo consumed ectomycorrhizal fungi, suggesting these birds played a role in dispersing fungi that are key to NZ's natural forest ecosystems. We also provide the first DNA-based evidence that moa frequently supplemented their broad diets with ferns and mosses. Finally, we also find parasite taxa that provide insight into moa behavior, and present data supporting the hypothesis of coextinction between moa and several parasite species. Our study demonstrates that HTS sequencing of coprolites provides a powerful tool for resolving key aspects of ancient ecosystems and may rapidly provide information not obtainable by conventional paleoecological techniques, such as fossil analyses.

  18. Hsp12p and PAU genes are involved in ecological interactions between natural yeast strains.

    Science.gov (United States)

    Rivero, Damaríz; Berná, Luisa; Stefanini, Irene; Baruffini, Enrico; Bergerat, Agnes; Csikász-Nagy, Attila; De Filippo, Carlotta; Cavalieri, Duccio

    2015-08-01

    The coexistence of different yeasts in a single vineyard raises the question on how they communicate and why slow growers are not competed out. Genetically modified laboratory strains of Saccharomyces cerevisiae are extensively used to investigate ecological interactions, but little is known about the genes regulating cooperation and competition in ecologically relevant settings. Here, we present evidences of Hsp12p-dependent altruistic and contact-dependent competitive interactions between two natural yeast isolates. Hsp12p is released during cell death for public benefit by a fast-growing strain that also produces a killer toxin to inhibit growth of a slow grower that can enjoy the benefits of released Hsp12p. We also show that the protein Pau5p is essential in the defense against the killer effect. Our results demonstrate that the combined action of Hsp12p, Pau5p and a killer toxin is sufficient to steer a yeast community. © 2015 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Author contributions to ecological publications: What does it mean to be an author in modern ecological research?

    Directory of Open Access Journals (Sweden)

    John M Logan

    Full Text Available Authorship is a central element of scientific research carrying a variety of rewards and responsibilities, and while various guidelines exist, actual author contributions are often ambiguous. Inconsistent or limited contributions threaten to devalue authorship as intellectual currency and diminish authors' responsibility for published content. Researchers have assessed author contributions in the medical literature and other research fields, but similar data for the field of ecological research are lacking. Authorship practices in ecological research are broadly representative of a variety of fields due to the cross-disciplinary nature of collaborations in ecological studies. To better understand author contributions to current research, we distributed a survey regarding co-author contributions to a random selection of 996 lead authors of manuscripts published in ecological journals in 2010. We obtained useable responses from 45% of surveyed authors. Reported lead author contributions in ecological research studies consistently included conception of the project idea, data collection, analysis, and writing. Middle and last author contributions instead showed a high level of individual variability. Lead authorship in ecology is well defined while secondary authorship is more ambiguous. Nearly half (48% of all studies included in our survey had some level of non-compliance with Ecological Society of America (ESA authorship guidelines and the majority of studies (78% contained at least one co-author that did not meet International Committee of Medical Journal Editors (ICMJE requirements. Incidence of non-compliance varied with lead author occupation and author position. The probability of a study including an author that was non-compliant with ESA guidelines was lowest for professor-led studies and highest for graduate student and post doctoral researcher-led studies. Among studies with > two co-authors, all lead authors met ESA guidelines and only

  20. Species interactions in the western Baltic Sea: With focus on the ecological role of whiting

    DEFF Research Database (Denmark)

    Ross, Stine Dalmann

    , which potentially prey on and compete for food with whiting. Here, the growth dynamics and feeding ecology of whiting in the western Baltic Sea is investigated and discussed in an ecosystem context. Furthermore, the diet of the harbour porpoise is examined and the interactions between whiting, cod......, implementation of the models in strategic management advice for commercially important fish stocks and protected marine mammals is not common practice. This is due to the lack of sufficient information about species interactions including knowledge about the diet, food intake and growth dynamics. This thesis...

  1. Ecological turmoil in evolutionary dynamics of plant-insect interactions: defense to offence

    Czech Academy of Sciences Publication Activity Database

    Mishra, Manasi; Lomate, P. R.; Joshi, R. S.; Punekar, S. A.; Gupta, V. S.; Giri, A. P.

    2015-01-01

    Roč. 242, č. 4 (2015), s. 761-771 ISSN 0032-0935 Institutional support: RVO:61388963 Keywords : plant-insect interaction * co-evolution * human interference * ecosystem * climatic change Subject RIV: CE - Biochemistry Impact factor: 3.239, year: 2015

  2. Identification of NCAM that interacts with the PHE-CoV spike protein.

    Science.gov (United States)

    Gao, Wei; He, Wenqi; Zhao, Kui; Lu, Huijun; Ren, Wenzhi; Du, Chongtao; Chen, Keyan; Lan, Yungang; Song, Deguang; Gao, Feng

    2010-09-24

    The spike proteins of coronaviruses associate with cellular molecules to mediate infection of their target cells. The characterization of cellular proteins required for virus infection is essential for understanding viral life cycles and may provide cellular targets for antiviral therapies. We identified Neural Cell Adhesion Molecule (NCAM) as a novel interacting partner of the PHE-CoV S protein. A T7 phage display cDNA library from N2a cells was constructed, and the library was screened with the soluble PHE-CoV S glycoproteins. We used a coimmunoprecipitation assay to show that only the NCAM was a binding partner of spike protein. We found that a soluble form of anti-NCAM antibody blocked association of the PHE-CoV with N2a cells. Furthermore, double-stranded siRNA targeted against NCAM inhibited PHE-CoV infection. A novel interaction was identified between NCAM and spike protein and this association is critical during PHE-CoV infection.

  3. Identification of NCAM that interacts with the PHE-CoV spike protein

    Directory of Open Access Journals (Sweden)

    Chen Keyan

    2010-09-01

    Full Text Available Abstract Background The spike proteins of coronaviruses associate with cellular molecules to mediate infection of their target cells. The characterization of cellular proteins required for virus infection is essential for understanding viral life cycles and may provide cellular targets for antiviral therapies. Results We identified Neural Cell Adhesion Molecule (NCAM as a novel interacting partner of the PHE-CoV S protein. A T7 phage display cDNA library from N2a cells was constructed, and the library was screened with the soluble PHE-CoV S glycoproteins. We used a coimmunoprecipitation assay to show that only the NCAM was a binding partner of spike protein. We found that a soluble form of anti-NCAM antibody blocked association of the PHE-CoV with N2a cells. Furthermore, double-stranded siRNA targeted against NCAM inhibited PHE-CoV infection. Conclusions A novel interaction was identified between NCAM and spike protein and this association is critical during PHE-CoV infection.

  4. Inference of Interactions in Cyanobacterial-Heterotrophic Co-Cultures via Transcriptome Sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Beliaev, Alex S.; Romine, Margaret F.; Serres, Margaret; Bernstein, Hans C.; Linggi, Bryan E.; Markillie, Lye Meng; Isern, Nancy G.; Chrisler, William B.; Kucek, Leo A.; Hill, Eric A.; Pinchuk, Grigoriy; Bryant, Donald A.; Wiley, H. S.; Fredrickson, Jim K.; Konopka, Allan

    2014-04-29

    We employed deep sequencing technology to identify transcriptional adaptation of the euryhaline unicellular cyanobacterium Synechococcus sp. PCC 7002 and the marine facultative aerobe Shewanella putrefaciens W3-18-1 to growth in a co-culture and infer the effect of carbon flux distributions on photoautotroph-heterotroph interactions. The overall transcriptome response of both organisms to co-cultivation was shaped by their respective physiologies and growth constraints. Carbon limitation resulted in the expansion of metabolic capacities which was manifested through the transcriptional upregulation of transport and catabolic pathways. While growth coupling occurred via lactate oxidation or secretion of photosynthetically fixed carbon, there was evidence of specific metabolic interactions between the two organisms. On one hand, the production and excretion of specific amino acids (methionine and alanine) by the cyanobacterium correlated with the putative downregulation of the corresponding biosynthetic machinery of Shewanella W3-18-1. On the other hand, the broad and consistent decrease of mRNA levels for many Fe-regulated Synechococcus 7002 genes during co-cultivation suggested increased Fe availability as well as more facile and energy-efficient mechanisms for Fe acquisition by the cyanobacterium. Furthermore, evidence pointed at potentially novel interactions between oxygenic photoautotrophs and heterotrophs related to the oxidative stress response as transcriptional patterns suggested that Synechococcus 7002 rather than Shewanella W3-18-1 provided scavenging functions for reactive oxygen species under co-culture conditions. This study provides an initial insight into the complexity of photoautotrophic-heterotrophic interactions and brings new perspectives of their role in the robustness and stability of the association.

  5. Geographic distribution and ecological niche of plague in sub-Saharan Africa

    DEFF Research Database (Denmark)

    Neerinckx, Simon B; Peterson, Andrew T; Gulinck, Hubert

    2008-01-01

    Background Plague is a rapidly progressing, serious illness in humans that is likely to be fatal if not treated. It remains a public health threat, especially in sub-Saharan Africa. In spite of plague's highly focal nature, a thorough ecological understanding of the general distribution pattern...... of plague across sub-Saharan Africa has not been established to date. In this study, we used human plague data from sub-Saharan Africa for 1970-2007 in an ecological niche modeling framework to explore the potential geographic distribution of plague and its ecological requirements across Africa. Results We...... predict a broad potential distributional area of plague occurrences across sub-Saharan Africa. General tests of model's transferability suggest that our model can anticipate the potential distribution of plague occurrences in Madagascar and northern Africa. However, generality and predictive ability tests...

  6. Co-occurrence of behavioral risk factors for chronic non-communicable diseases in adolescents: Prevalence and associated factors

    Directory of Open Access Journals (Sweden)

    Alessandra Silva Dias de OLIVEIRA

    Full Text Available ABSTRACT Objective To examine the prevalence of the behavioral risk factors – both isolated and clustered – for chronic diseases, among adolescents. Additionally, its association with various social and demographic variables was estimated. Methods This was a cross-sectional study conducted on 1,039 high school students, from public and private schools, elected for convenience, in Rio de Janeiro, Brazil. A Chi-square test, Mann-Whitney U test, as well as crude and adjusted ordinal logistic regression were used to assess the association between the variables. Results The most frequently observed risk factors were sedentary behavior (68.8%, alcohol consumption (36.8%, and overweight (26.8%. The clustering of risk factors was observed in 67.5% of the students. Being a girl (OR=1.28; 95%CI=1.01–1.63, Caucasian (OR=1.35; 95%CI=1.06–1.72 or private school student (OR=1.46; 95%CI=1.12–1.88 increased the chance of the clustering of risk factors. The co-occurrence of risk factors was predominantly observed in the case of smoking (OR=4.94; 95%CI=1.46–16.75, alcohol consumption (OR=1.43; 95%CI=1.09–1.88, high consumption of ultra-processed foods (OR=1.57; 95%CI=1.19–2.07, and sedentary behavior (OR=1.40; 95%CI=1.07–1.82. Conclusion The co-occurrence of behavioral risk factors was observed to be higher among girls, Caucasian adolescents, and private school students, as well as, among smokers, alcohol users and adolescents with sedentary habits and a high consumption of ultra-processed foods.

  7. Mechanisms underlying the lifetime co-occurrence of tobacco and cannabis use in adolescent and young adult twins

    Science.gov (United States)

    Agrawal, Arpana; Silberg, Judy L.; Lynskey, Michael T.; Maes, Hermine H.; Eaves, Lindon J.

    2009-01-01

    Using twins assessed during adolescence (Virginia Twin Study of Adolescent Behavioral Development: 8–17 years) and followed up in early adulthood (Young Adult Follow-Up, 18–27 years), we tested 13 genetically informative models of co-occurrence, adapted for the inclusion of covariates. Models were fit, in Mx, to data at both assessments allowing for a comparison of the mechanisms that underlie the lifetime co-occurrence of cannabis and tobacco use in adolescence and early adulthood. Both cannabis and tobacco use were influenced by additive genetic (38–81%) and non-shared environmental factors with the possible role of non-shared environment in the adolescent assessment only. Causation models, where liability to use cannabis exerted a causal influence on the liability to use tobacco fit the adolescent data best, while the reverse causation model (tobacco causes cannabis) fit the early adult data best. Both causation models (cannabis to tobacco and tobacco to cannabis) and the correlated liabilities model fit data from the adolescent and young adult assessments well. Genetic correlations (0.59–0.74) were moderate. Therefore, the relationship between cannabis and tobacco use is fairly similar during adolescence and early adulthood with reciprocal influences across the two psychoactive substances. However, our study could not exclude the possibility that ‘gateways’ and ‘reverse gateways’, particularly within a genetic context, exist, such that predisposition to using one substance (cannabis or tobacco) modifies predisposition to using the other. Given the high addictive potential of nicotine and the ubiquitous nature of cannabis use, this is a public health concern worthy of considerable attention. PMID:20047801

  8. 350 Years of Fire-Climate-Human Interactions in a Great Lakes Sandy Outwash Plain

    Directory of Open Access Journals (Sweden)

    Richard P. Guyette

    2016-08-01

    Full Text Available Throughout much of eastern North America, quantitative records of historical fire regimes and interactions with humans are absent. Annual resolution fire scar histories provide data on fire frequency, extent, and severity, but also can be used to understand fire-climate-human interactions. This study used tree-ring dated fire scars from red pines (Pinus resinosa at four sites in the Northern Sands Ecological Landscapes of Wisconsin to quantify the interactions among fire occurrence and seasonality, drought, and humans. New methods for assessing the influence of human ignitions on fire regimes were developed. A temporal and spatial index of wildland fire was significantly correlated (r = 0.48 with drought indices (Palmer Drought Severity Index, PDSI. Fire intervals varied through time with human activities that included early French Jesuit missions, European trade (fur, diseases, war, and land use. Comparisons of historical fire records suggest that annual climate in this region has a broad influence on the occurrence of fire years in the Great Lakes region.

  9. The fundamental role of ecological feedback mechanisms for the adaptive management of seagrass ecosystems - a review.

    Science.gov (United States)

    Maxwell, Paul S; Eklöf, Johan S; van Katwijk, Marieke M; O'Brien, Katherine R; de la Torre-Castro, Maricela; Boström, Christoffer; Bouma, Tjeerd J; Krause-Jensen, Dorte; Unsworth, Richard K F; van Tussenbroek, Brigitta I; van der Heide, Tjisse

    2017-08-01

    Seagrass meadows are vital ecosystems in coastal zones worldwide, but are also under global threat. One of the major hurdles restricting the success of seagrass conservation and restoration is our limited understanding of ecological feedback mechanisms. In these ecosystems, multiple, self-reinforcing feedbacks can undermine conservation efforts by masking environmental impacts until the decline is precipitous, or alternatively they can inhibit seagrass recovery in spite of restoration efforts. However, no clear framework yet exists for identifying or dealing with feedbacks to improve the management of seagrass ecosystems. Here we review the causes and consequences of multiple feedbacks between seagrass and biotic and/or abiotic processes. We demonstrate how feedbacks have the potential to impose or reinforce regimes of either seagrass dominance or unvegetated substrate, and how the strength and importance of these feedbacks vary across environmental gradients. Although a myriad of feedbacks have now been identified, the co-occurrence and likely interaction among feedbacks has largely been overlooked to date due to difficulties in analysis and detection. Here we take a fundamental step forward by modelling the interactions among two distinct above- and belowground feedbacks to demonstrate that interacting feedbacks are likely to be important for ecosystem resilience. On this basis, we propose a five-step adaptive management plan to address feedback dynamics for effective conservation and restoration strategies. The management plan provides guidance to aid in the identification and prioritisation of likely feedbacks in different seagrass ecosystems. © 2016 Cambridge Philosophical Society.

  10. Co-Occurring Atomic Contacts for the Characterization of Protein Binding Hot Spots

    Science.gov (United States)

    Liu, Qian; Ren, Jing; Song, Jiangning; Li, Jinyan

    2015-01-01

    A binding hot spot is a small area at a protein-protein interface that can make significant contribution to binding free energy. This work investigates the substantial contribution made by some special co-occurring atomic contacts at a binding hot spot. A co-occurring atomic contact is a pair of atomic contacts that are close to each other with no more than three covalent-bond steps. We found that two kinds of co-occurring atomic contacts can play an important part in the accurate prediction of binding hot spot residues. One is the co-occurrence of two nearby hydrogen bonds. For example, mutations of any residue in a hydrogen bond network consisting of multiple co-occurring hydrogen bonds could disrupt the interaction considerably. The other kind of co-occurring atomic contact is the co-occurrence of a hydrophobic carbon contact and a contact between a hydrophobic carbon atom and a π ring. In fact, this co-occurrence signifies the collective effect of hydrophobic contacts. We also found that the B-factor measurements of several specific groups of amino acids are useful for the prediction of hot spots. Taking the B-factor, individual atomic contacts and the co-occurring contacts as features, we developed a new prediction method and thoroughly assessed its performance via cross-validation and independent dataset test. The results show that our method achieves higher prediction performance than well-known methods such as Robetta, FoldX and Hotpoint. We conclude that these contact descriptors, in particular the novel co-occurring atomic contacts, can be used to facilitate accurate and interpretable characterization of protein binding hot spots. PMID:26675422

  11. How will climate novelty influence ecological forecasts? Using the Quaternary to assess future reliability.

    Science.gov (United States)

    Fitzpatrick, Matthew C; Blois, Jessica L; Williams, John W; Nieto-Lugilde, Diego; Maguire, Kaitlin C; Lorenz, David J

    2018-03-23

    Future climates are projected to be highly novel relative to recent climates. Climate novelty challenges models that correlate ecological patterns to climate variables and then use these relationships to forecast ecological responses to future climate change. Here, we quantify the magnitude and ecological significance of future climate novelty by comparing it to novel climates over the past 21,000 years in North America. We then use relationships between model performance and climate novelty derived from the fossil pollen record from eastern North America to estimate the expected decrease in predictive skill of ecological forecasting models as future climate novelty increases. We show that, in the high emissions scenario (RCP 8.5) and by late 21st century, future climate novelty is similar to or higher than peak levels of climate novelty over the last 21,000 years. The accuracy of ecological forecasting models is projected to decline steadily over the coming decades in response to increasing climate novelty, although models that incorporate co-occurrences among species may retain somewhat higher predictive skill. In addition to quantifying future climate novelty in the context of late Quaternary climate change, this work underscores the challenges of making reliable forecasts to an increasingly novel future, while highlighting the need to assess potential avenues for improvement, such as increased reliance on geological analogs for future novel climates and improving existing models by pooling data through time and incorporating assemblage-level information. © 2018 John Wiley & Sons Ltd.

  12. CO interaction with Cu(I)-MCM-22 zeolite: density function theory investigation

    International Nuclear Information System (INIS)

    Viet Thang Ho; Petr Nachtigall

    2014-01-01

    MCM-22 zeolite has been widely used in many applications for catalysis and adsorption. Especially, this material exchanged with Cu + cation (Cu(I)-MCM-22) is an active catalyst in green chemical reaction, such as decomposition of NO and N 2 O. The local geometry of Cu + in vicinity of Al (III) replacement in six different Si (IV) sites and CO interaction with the most stable Cu + in each Al site were explored using periodic density functional theory (DFT) method. Th CO stretching frequencies were computed applying the ω/r scaling method in which frequencies were determined at high quantum level (couple cluster) and CO bond length calculated at DFT level. The results showed that Cu + cation located in the channel wall position and intersection position coordinated with 3 or 2 framework oxygen atoms, respectively, before CO adsorption and Cu + cation coordinated with 2 framework oxygen atoms after CO adsorption. The interaction energies between CO and Cu + cation were in range -148 to -195 kJ/mol -1 and CO frequencies exhibit two peak at 2151 and 2159 cm -1 in good agreement with experimental data. This investigation allows to understand the Cu + location in MCM-22 and CO adsorption in Cu(I)-MCM-22 zeolite. (author)

  13. Spinal pain and co-occurrence with stress and general well-being among young adolescents

    DEFF Research Database (Denmark)

    Stallknecht, Sandra Elkjær; Strandberg-Larsen, Katrine; Hestbæk, Lise

    2017-01-01

    This study aims to describe the patterns in low back, mid back, and neck pain complaints in young adolescents from the Danish National Birth Cohort (DNBC) and to investigate the co-occurrence of spinal pain and stress and general well-being, respectively. Cross-sectional data from the 11-year...... follow-up of DNBC were used. As part of a web-based survey, a total of 45,371 young adolescents between 10 and 14 years old completed the Young Spine Questionnaire, the Stress in Children Questionnaire, and a one-item question on general well-being. Associations between spinal pain and, respectively......, stress and general well-being were estimated by means of multiple logistic regression models. Almost one fifth of boys and one quarter of girls reported spinal pain. Compared with adolescents who reported no stress, adolescents reporting medium and high values of stress had odds ratios (OR) of 2.19 (95...

  14. Potential occurrence of the birch mouse (Sicista betulina) in the Bohemian Forest (Šumava): A geographical information system approach

    Czech Academy of Sciences Publication Activity Database

    Weiter, L.; Heřman, Michal; Sedláček, František; Zemek, František

    2002-01-01

    Roč. 51, č. 1 (2002), s. 133-144 ISSN 0139-7893 Institutional research plan: CEZ:AV0Z6087904 Keywords : model of occurrence * preferences of ecological factors Subject RIV: EH - Ecology, Behaviour Impact factor: 0.234, year: 2002

  15. Lessons from Philippines MPA Management: Social Ecological Interactions, Participation, and MPA Performance

    Science.gov (United States)

    Twichell, Julia; Pollnac, Richard; Christie, Patrick

    2018-06-01

    International interest in increasing marine protected area (MPA) coverage reflects broad recognition of the MPA as a key tool for marine ecosystems and fisheries management. Nevertheless, effective management remains a significant challenge. The present study contributes to enriching an understanding of best practices for MPA management through analysis of archived community survey data collected in the Philippines by the Learning Project (LP), a collaboration with United States Coral Triangle Initiative (USCTI), United States Agency for International Development (USAID), and partners. We evaluate stakeholder participation and social ecological interactions among resource users in MPA programs in the Palawan, Occidental Mindoro, and Batangas provinces in the Philippines. Analysis indicates that a complex suite of social ecological factors, including demographics, conservation beliefs, and scientifically correct knowledge influence participation, which in turn is related to perceived MPA performance. Findings indicate positive feedbacks within the system that have potential to strengthen perceptions of MPA success. The results of this evaluation provide empirical reinforcement to current inquiries concerning the role of participation in influencing MPA performance.

  16. Lessons from Philippines MPA Management: Social Ecological Interactions, Participation, and MPA Performance.

    Science.gov (United States)

    Twichell, Julia; Pollnac, Richard; Christie, Patrick

    2018-06-01

    International interest in increasing marine protected area (MPA) coverage reflects broad recognition of the MPA as a key tool for marine ecosystems and fisheries management. Nevertheless, effective management remains a significant challenge. The present study contributes to enriching an understanding of best practices for MPA management through analysis of archived community survey data collected in the Philippines by the Learning Project (LP), a collaboration with United States Coral Triangle Initiative (USCTI), United States Agency for International Development (USAID), and partners. We evaluate stakeholder participation and social ecological interactions among resource users in MPA programs in the Palawan, Occidental Mindoro, and Batangas provinces in the Philippines. Analysis indicates that a complex suite of social ecological factors, including demographics, conservation beliefs, and scientifically correct knowledge influence participation, which in turn is related to perceived MPA performance. Findings indicate positive feedbacks within the system that have potential to strengthen perceptions of MPA success. The results of this evaluation provide empirical reinforcement to current inquiries concerning the role of participation in influencing MPA performance.

  17. Neighborhood Socioeconomic Circumstances and the Co-Occurrence of Unhealthy Lifestyles: Evidence from 206,457 Australians in the 45 and Up Study

    OpenAIRE

    Feng, Xiaoqi; Astell-Burt, Thomas

    2013-01-01

    Background Research on the co-occurrence of unhealthy lifestyles has tended to focus mainly upon the demographic and socioeconomic characteristics of individuals. This study investigated the relevance of neighborhood socioeconomic circumstance for multiple unhealthy lifestyles. Method An unhealthy lifestyle index was constructed for 206,457 participants in the 45 and Up Study (2006?2009) by summing binary responses on smoking, alcohol, physical activity and five diet-related variables. Higher...

  18. Functional and ecological consequences of saprotrophic fungus-grazer interactions.

    Science.gov (United States)

    Crowther, Thomas W; Boddy, Lynne; Hefin Jones, T

    2012-11-01

    Saprotrophic fungi are key regulators of nutrient cycling in terrestrial ecosystems. They are the primary agents of plant litter decomposition and their hyphal networks, which grow throughout the soil-litter interface, represent highly dynamic channels through which nutrients are readily distributed. By ingesting hyphae and dispersing spores, soil invertebrates, including Arthropoda, Oligochaetae and Nematoda, influence fungal-mediated nutrient distribution within soil. Fungal physiological responses to grazing include changes to hydrolytic enzyme production and respiration rates. These directly affect nutrient mineralisation and the flux of CO(2) between terrestrial and atmospheric pools. Preferential grazing may also exert selective pressures on saprotrophic communities, driving shifts in fungal succession and community composition. These functional and ecological consequences of grazing are intrinsically linked, and influenced by invertebrate grazing intensity. High-intensity grazing often reduces fungal growth and activity, whereas low-intensity grazing can have stimulatory effects. Grazing intensity is directly related to invertebrate abundance, and varies dramatically between species and functional groups. Invertebrate diversity and community composition, therefore, represent key factors determining the functioning of saprotrophic fungal communities and the services they provide.

  19. Hyperfine Interaction Studies on Y, Zr, Nb, Mo, Rh, In and Xe in Co

    International Nuclear Information System (INIS)

    Seewald, G.; Zech, E.; Ratai, H.; Schmid, R.; Stadler, R.; Schramm, O.; Koenig, C.; Hinfurtner, B.; Hagn, E.; Deicher, M.; Eder, R.; Forkel-Wirth, D.

    2004-01-01

    Nuclear magnetic resonance on oriented nuclei and modulated adiabatic fast passage on oriented nuclei measurements were performed on several 4d and 5sp impurities in polycrystalline Co(fcc) foils and Co(hcp) single crystals. The hyperfine fields of Y and Zr in Co(fcc), the hyperfine fields of Y, Zr, Nb, Mo, Rh, In and Xe in Co(hcp), the electric field gradients of Zr, Nb and In in Co(hcp), and the nuclear spin-lattice relaxations of Zr, Nb, Rh and In in Co(hcp) were determined. The dependence of the hyperfine fields and electric field gradients in Co(hcp) on the angle between the magnetization and the c axis was investigated in most cases. The magnetic-field dependence of the spin-lattice relaxation was studied for Nb, Rh and In in Co(hcp), applying the magnetic field perpendicular to the c axis. The known hyperfine interaction parameters of the4d and 5sp impurities in Co(fcc) and Co(hcp) are summarized. The new results provide a more detailed picture of the hyperfine interaction in Co.

  20. Towards More Effective Water Quality Governance: A Review of Social-Economic, Legal and Ecological Perspectives and Their Interactions

    Directory of Open Access Journals (Sweden)

    Susanne Wuijts

    2018-03-01

    Full Text Available In this article, social-economic, legal and ecological perspectives on effectiveness of water quality governance and their interactions have been studied. Worldwide, authorities are facing the challenge of restoring and preserving aquatic ecosystems in accordance with the United Nations Sustainable Development Goals (SDG 6. Over the last few decades, governance approaches have often been used to realise these ambitions. To date, scholars have identified that it is difficult to relate governance approaches to water quality improvement and have offered several different explanations for this. Combined with a targeted conceptualisation of the perspectives and their interactions, the systematic literature review demonstrates the gap that exists in the current understanding of these interactions and what their effects are on water quality improvement, especially in regard to the identification of ecological issues and their boundary conditions for the legal framework and the development of measures and follow-up. The review also reveals that the scientific debate is focused on the planning rather than implementation phase. A step forward can be made by supplementing existing analytical frameworks by the interactions between the different perspectives, especially those related to problem definition and the development and realisation of measures.

  1. PENGENALAN PENY AKIT NODA PADA CITRA DAUN TEBU BERDASARKAN CIRI TEKSTUR FRACTAL DIMENSION CO-OCCURRENCE MATRIX DAN L*a*b* COLOR MOMENTS

    Directory of Open Access Journals (Sweden)

    Evy Kamilah Ratnasari

    2014-07-01

    Full Text Available Penyakit yang menyerang tebu dapat disebabkan oleh bakteri, jamur maupun virus. Penyakit noda merupakan penyakit pada tanaman tebu yang disebabkan oleh jamur dengan menampakkan lesi atau bercak pada permukaan daun. Penyakit noda tersebut dapat menghambat proses fotosintesis yang akan berakibat menurunkan produksi gula karena mempengaruhi pertumbuhan tebu. Upaya pengendalian dini dapat dilakukan dengan mengenali jenis penyakit melalui lesinya yang bermanfaat dalam menentukan tindakan penanganan yang tepat. Lesi yang disebabkan oleh penyakit noda masing-masing dapat dikenali secara visual karena memiliki ciri warna dan tekstur yang unik. Tetapi pengamatan secara visual memiliki beberapa kekurangan seperti subjektifitas dan kurang akurat. Penelitian ini mengusulkan pengenalan penyakit noda tanaman tebu yang terdiri dari noda cincin, noda karat, dan noda kuning berdasarkan fitur tekstur yang merupakan kombinasi dari konsep Gray Level Co-Occurrence Matrix (GLCM dan dimensi fraktal yang dinamakan Fractal Dimension Co-Occurrence Matrix (FDCM. Sedangkan fitur warna didapatkan dari perhitungan statistik col or moments pada citra L*a*b*. Kombinasi fitur tersebut menghasilkan 12 fitur warna dan 6 fitur tekstur yang kemudian digunakan sebagai masukan klasifikasi k-Nearest Neighbor (KNN. Pengenalan penyakit noda pada tanaman tebu menggunakan metode tersebut dapat menghasilkan akurasi tertinggi 90%.

  2. Toward Political Ecologies of Environmental Education

    Science.gov (United States)

    Henderson, Joseph A.; Zarger, Rebecca K.

    2017-01-01

    Drawing a causal line between educational practice and ecological impact is a difficult intellectual task given the complexity of variables at work between educational event and ecological effect. This is further complicated by the anthropological fact that diverse peoples interact with nature in myriad ways. Our environmental interactions are…

  3. Interaction of scandium sesquioxide with carbon

    International Nuclear Information System (INIS)

    Vodop'yanov, A.G.; Zakharov, R.G.

    1986-01-01

    In the range of 2350-2470 degrees K at a PCO = 0.0 MPa, interaction in Sc 2 O 3 with carbon mixtures initially occurs by CO chemisorption at the scandium oxide surface and disproportionation into CO 2 and C, with subsequent replacement of oxygen in the oxide anion sublattice by carbon to form ScC. The carbide melt, creating a contact between the reagents, then transforms the process to a diffusion-based one. At 1820-2220 K in vacuum, reduction of the studied mixtures occurs by dissociative vaporization of the oxide, with precipitation of ScC at the carbon surface and generation of CO. The appearance of CO in the vapors of mixture leads to formation of an oxycarbide phase and to the partial occurrence of oxide dissociation

  4. 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

  5. Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments

    Science.gov (United States)

    Cassada, David A.; Bartelt–Hunt, Shannon L.; Li, Xu; D’Alessio, Matteo; Zhang, Yun; Zhang, Yuping; Sallach, J. Brett

    2018-01-01

    A total of 59 papers published in 2015 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, steroids, antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Steroid Hormones, Pharmaceutical Contaminants, Transformation Products, and “Antibiotic Resistance, Drugs, Bugs and Genes”. PMID:27620078

  6. Dynamic assessment of microbial ecology (DAME): a web app for interactive analysis and visualization of microbial sequencing data.

    Science.gov (United States)

    Piccolo, Brian D; Wankhade, Umesh D; Chintapalli, Sree V; Bhattacharyya, Sudeepa; Chunqiao, Luo; Shankar, Kartik

    2018-03-15

    Dynamic assessment of microbial ecology (DAME) is a Shiny-based web application for interactive analysis and visualization of microbial sequencing data. DAME provides researchers not familiar with R programming the ability to access the most current R functions utilized for ecology and gene sequencing data analyses. Currently, DAME supports group comparisons of several ecological estimates of α-diversity and β-diversity, along with differential abundance analysis of individual taxa. Using the Shiny framework, the user has complete control of all aspects of the data analysis, including sample/experimental group selection and filtering, estimate selection, statistical methods and visualization parameters. Furthermore, graphical and tabular outputs are supported by R packages using D3.js and are fully interactive. DAME was implemented in R but can be modified by Hypertext Markup Language (HTML), Cascading Style Sheets (CSS), and JavaScript. It is freely available on the web at https://acnc-shinyapps.shinyapps.io/DAME/. Local installation and source code are available through Github (https://github.com/bdpiccolo/ACNC-DAME). Any system with R can launch DAME locally provided the shiny package is installed. bdpiccolo@uams.edu.

  7. Using network to enhance the insights on correlation and pollution assessment of co-occurring metals in marine sediments, the East China Sea.

    Science.gov (United States)

    Liu, Lili; Wang, Yupeng; Lin, Sen; Li, Hong; Chen, Xin; Wang, Zhiping; Lin, Kuangfei

    2018-02-14

    In this study, sediment samples were collected from 24 sites in the East China Sea (ECS) to investigate the distribution characteristics, co-occurrence correlations, and ecological risks of metals. In surface sediments, metals presented a homologous banding distribution pattern decreasing seaward with distance. With network analysis, it indicated metals in this area might directly derive from the coastal river inputs. According to geo-accumulation indexes (I geo ), Cd was classified as moderate pollution at 58% sites, far above other metals. In addition, the potential ecological risk index (RI) was clustered with the ecological risk (ER) of Cd, which was regarded as considerable or high-risk level for most coastal stations. Thus Cd pollution in the ESC sediment should be paid more attention. In sum, the visualization of statistical analyses combined with geochemical approaches could reveal the potential sources of contaminants and ecological risks, thus facilitate the pollution evaluation in marine sediments.

  8. Co-occurrence of addictive behaviours: personality factors related to substance use, gambling and computer gaming.

    Science.gov (United States)

    Walther, Birte; Morgenstern, Matthis; Hanewinkel, Reiner

    2012-01-01

    To investigate co-occurrence and shared personality characteristics of problematic computer gaming, problematic gambling and substance use. Cross-sectional survey data were collected from 2,553 German students aged 12-25 years. Self-report measures of substance use (alcohol, tobacco and cannabis), problematic gambling (South Oaks Gambling Screen - Revised for Adolescents, SOGS-RA), problematic computer gaming (Video Game Dependency Scale, KFN-CSAS-II), and of twelve different personality characteristics were obtained. Analyses revealed positive correlations between tobacco, alcohol and cannabis use and a smaller positive correlation between problematic gambling and problematic computer gaming. Problematic computer gaming co-occurred only with cannabis use, whereas problematic gambling was associated with all three types of substance use. Multivariate multilevel analyses showed differential patterns of personality characteristics. High impulsivity was the only personality characteristic associated with all five addictive behaviours. Depression and extraversion were specific to substance users. Four personality characteristics were specifically associated with problematic computer gaming: irritability/aggression, social anxiety, ADHD, and low self-esteem. Problematic gamblers seem to be more similar to substance users than problematic computer gamers. From a personality perspective, results correspond to the inclusion of gambling in the same DSM-V category as substance use and question a one-to-one proceeding for computer gaming. Copyright © 2012 S. Karger AG, Basel.

  9. Analysis of Ecosystem Service Supply, Trade-Offs and Soical-Ecological Interactions in European Wood-Pastures

    DEFF Research Database (Denmark)

    Torralba Viorreta, Mario

    (Östergötland in Sweden, Southern Transylvania in Romania, Llanos de Trujillo in Spain and La Serena in Spain). The thesis provides an understanding of the dynamics and mechanisms interacting in the generation of ecosystem services in European wood-pastures, and the factors that govern this supply. The results...... show that wood-pastures offer a wide range of ecosystem services, which is due to, on the one hand, the high multifunctionality that characterizes them and, on the other hand, the multiple socio-cultural values they host. However, the specific interactions between the social and ecological components...

  10. Supervised and Unsupervised Aspect Category Detection for Sentiment Analysis with Co-occurrence Data.

    Science.gov (United States)

    Schouten, Kim; van der Weijde, Onne; Frasincar, Flavius; Dekker, Rommert

    2018-04-01

    Using online consumer reviews as electronic word of mouth to assist purchase-decision making has become increasingly popular. The Web provides an extensive source of consumer reviews, but one can hardly read all reviews to obtain a fair evaluation of a product or service. A text processing framework that can summarize reviews, would therefore be desirable. A subtask to be performed by such a framework would be to find the general aspect categories addressed in review sentences, for which this paper presents two methods. In contrast to most existing approaches, the first method presented is an unsupervised method that applies association rule mining on co-occurrence frequency data obtained from a corpus to find these aspect categories. While not on par with state-of-the-art supervised methods, the proposed unsupervised method performs better than several simple baselines, a similar but supervised method, and a supervised baseline, with an -score of 67%. The second method is a supervised variant that outperforms existing methods with an -score of 84%.

  11. Influence of Ce-H bonding on the physical properties of the hydrides CeCoSiH1.0 and CeCoGeH1.0

    International Nuclear Information System (INIS)

    Chevalier, B; Matar, S F; Menetrier, M; Marcos, J Sanchez; Fernandez, J Rodriguez

    2006-01-01

    The hydrides CeCoSiH 1.0 and CeCoGeH 1.0 which crystallize like the parent antiferromagnetic compounds CeCoSi and CeCoGe in the tetragonal CeFeSi-type structure, have been investigated by specific heat and thermoelectric power measurements and 1 H nuclear magnetic resonance (NMR). CeCoSiH 1.0 is an intermediate valence compound whereas CeCoGeH 1.0 can be considered as a nearly trivalent cerium compound. This behaviour is corroborated by the occurrence of a slight broadening of the 1 H NMR signal in the sequence CeCoSiH 1.0 → CeCoGeH 1.0 . The band structure calculations performed on these hydrides reveal the existence of strong bonding Ce-H interaction, found to be larger in CeCoSiH 1.0 than in CeCoGeH 1.0

  12. The Amazing Ecology of Terrestrial Isopods

    Science.gov (United States)

    Dobson, Christopher; Postema, Dan

    2014-01-01

    Ecology is the study of how organisms interact with their environment, and the best place to see these interactions is outside in natural habitats. Pillbugs (roly-polies) provide an excellent opportunity for students to learn ecological concepts through inquiry. Because of their fascinating behaviors, pillbugs are ideal organisms to introduce…

  13. Examining ecological validity in social interaction: problems of visual fidelity, gaze, and social potential.

    Science.gov (United States)

    Reader, Arran T; Holmes, Nicholas P

    2016-01-01

    Social interaction is an essential part of the human experience, and much work has been done to study it. However, several common approaches to examining social interactions in psychological research may inadvertently either unnaturally constrain the observed behaviour by causing it to deviate from naturalistic performance, or introduce unwanted sources of variance. In particular, these sources are the differences between naturalistic and experimental behaviour that occur from changes in visual fidelity (quality of the observed stimuli), gaze (whether it is controlled for in the stimuli), and social potential (potential for the stimuli to provide actual interaction). We expand on these possible sources of extraneous variance and why they may be important. We review the ways in which experimenters have developed novel designs to remove these sources of extraneous variance. New experimental designs using a 'two-person' approach are argued to be one of the most effective ways to develop more ecologically valid measures of social interaction, and we suggest that future work on social interaction should use these designs wherever possible.

  14. Co-occurrence of protective health behaviours and perceived psychosocial job characteristics

    Directory of Open Access Journals (Sweden)

    Vera J.C. Mc Carthy

    2015-01-01

    Full Text Available Little is known about the association between positive job characteristics of older workers and the co-occurrence of protective health behaviours. This study aims to investigate the association between perceived psychosocial job characteristics and the adoption of protective health behaviours. A population-based cross-sectional study was performed on a sample of 1025 males and females (age-range 50–69-years attending a primary healthcare clinic. Perceived job characteristics (job demands: quantitative and cognitive demands; resources: possibility for development and influence at work were determined using the Copenhagen Psychosocial Questionnaire. Each scale is presented in tertiles. Protective health behaviours were; consumption of five or more portions of fruit and vegetables a day, moderate alcohol, non/ex-smoker, and high and moderate physical activity. Each participant was scored 0–4 protective health behaviours. The majority of the sample had three protective health behaviours. Higher levels of influence at work and cognitive demands were associated with higher self-reported physical activity, but not with any number of protective health behaviours. Conversely, higher quantitative and higher cognitive demands were associated with reporting any number of protective health behaviours or above average number of protective health behaviours respectively. The findings on protective health behaviours were inconsistent in relation to the different measures of perceived psychosocial job characteristics and were largely confined to physical activity and diet.

  15. Traditional and cyberbullying co-occurrence and its relationship to psychiatric symptoms.

    Science.gov (United States)

    Tural Hesapcioglu, Selma; Ercan, Filiz

    2017-01-01

    The effect of cyberbullying accompanied by traditional bullying on mental health has been less studied. In this study, the frequency, co-occurrence, and the relationship to psychiatric symptoms of traditional bullying and cyberbullying among bullies and victims are examined. All of the high schools in the province of Mus, Turkey were stratified according to Placement Test for High Schools admission points for 2014-2015. By choosing schools using simple random sampling, 1276 students were reached. Students were given the Brief Symptom Inventory and three separate scale assessments: peer bullying rating, cybervictimization, and cyberbullying scales. High scores in all subscale scores of bullying and victimization were significantly related to higher depression, anxiety, low self-esteem, somatization, and hostility scores. For people who were exposed to cyberbullying in addition to traditional bullying, the severity of the psychiatric symptoms was significantly higher. For all psychiatric symptoms, major predictors were gender, total victimization score, and total cybervictimization score. Moreover, the bullying total score was among the predictors of low self-esteem and hostility. Cybervictimization and cyberbullying occur less often than traditional bullying and victimization, but people who were exposed to or performed cyberbullying were also exposed to or performed traditional bullying. The addition of cyberbullying to traditional bullying is associated with more intense psychiatric symptoms. © 2016 Japan Pediatric Society.

  16. Occurrence and ecological risk assessment of emerging organic chemicals in urban rivers

    NARCIS (Netherlands)

    Peng, Feng Jiao; Pan, Chang Gui; Zhang, Min; Zhang, Nai Sheng; Windfeld, Ronja; Salvito, Daniel; Selck, Henriette; Brink, Van den Paul J.; Ying, Guang Guo

    2017-01-01

    Urban rivers may receive contamination from various sources including point sources like domestic sewage and nonpoint sources (e.g., runoff), resulting in contamination with various chemicals. This study investigated the occurrence of emerging organic contaminants (3 endocrine disrupting

  17. Synergistic interactions of CO2 enrichment and nitrogen deposition promote growth and ecophysiological advantages of invading Eupatorium adenophorum in Southwest China.

    Science.gov (United States)

    Lei, Yan-bao; Wang, Wei-bin; Feng, Yu-long; Zheng, Yu-long; Gong, He-de

    2012-10-01

    Global environmental change and ongoing biological invasions are the two prominent ecological issues threatening biodiversity worldwide, and investigations of their interaction will aid to predict plant invasions and inform better management strategies in the future. In this study, invasive Eupatorium adenophorum and native congener E. stoechadosmum were compared at ambient and elevated atmospheric carbon dioxide (CO(2)) concentrations combined with three levels of nitrogen (N; reduced, control and increased) in terms of growth, energy gain, and cost. Compared with E. stoechadosmum, E. adenophorum adopted a quicker-return energy-use strategy, i.e. higher photosynthetic energy-use efficiency and shorter payback time. Lower leaf mass per area may be a pivotal trait for the invader, which contributed to an increased N allocation to Rubisco at the expense of cell walls and therefore to higher photosynthetic energy gain. CO(2) enrichment and N deposition synergistically promoted plant growth and influenced some related ecophysiological traits, and the synergistic effects were greater for the invader than for the native congener. Reducing N availability by applying sugar eliminated the advantages of the invader over its native congener at both CO(2) levels. Our results indicate that CO(2) enrichment and N deposition may exacerbate E. adenophorum's invasion in the future, and manipulating environmental resources such as N availability may be a feasible tool for managing invasion impacts of E. adenophorum.

  18. Pressure, O2, and CO2, in aquatic Closed Ecological Systems

    Science.gov (United States)

    Taub, Frieda B.; McLaskey, Anna K.

    2013-03-01

    Pressure increased during net photosynthetic O2 production in the light and decreased during respiratory O2 uptake during the dark in aquatic Closed Ecological Systems (CESs) with small head gas volumes. Because most CO2 will be in the liquid phase as bicarbonate and carbonate anions, and CO2 is more soluble than O2, volumes of gaseous CO2 and gaseous O2 will not change in a compensatory manner, leading to the development of pressure. Pressure increases were greatest with nutrient rich medium with NaHCO3 as the carbon source. With more dilute media, pressure was greatest with NaHCO3, and less with cellulose or no-added carbon. Without adequate turbulence, pressure measurements lagged dissolved O2 concentrations by several hours and dark respiration would have been especially underestimated in our systems (250-1000 ml). With adequate turbulence (rotary shaker), pressure measurements and dissolved O2 concentrations generally agreed during lights on/off cycles, but O2 measurements provided more detail. At 20 °C, 29.9 times as much O2 will distribute into the gas phase as in the liquid, per unit volume, as a result of the limited solubility of O2 in water and according to Henry's Law. Thus even a small head gas volume can contain more O2 than a larger volume of water. When both dissolved and gaseous O2 and CO2 are summed, the changes in Total O2 and CO2 are in relatively close agreement when NaHCO3 is the carbon source. These findings disprove an assumption made in some of Taub's earlier research that aquatic CESs would remain at approximately atmospheric pressure because approximately equal molar quantities of O2 and CO2 would exchange during photosynthesis and respiration; this assumption neglected the distribution of O2 between water and gas phases. High pressures can occur when NaHCO3 is the carbon source in nutrient rich media and if head-gas volumes are small relative to the liquid volume; e.g., one "worse case" condition developed 800 mm Hg above atmospheric

  19. Observability of planet-disc interactions in CO kinematics

    Science.gov (United States)

    Pérez, Sebastián; Casassus, S.; Benítez-Llambay, P.

    2018-06-01

    Empirical evidence of planets in gas-rich circumstellar discs is required to constrain giant planet formation theories. Here we study the kinematic patterns which arise from planet-disc interactions and their observability in CO rotational emission lines. We perform three-dimensional hydrodynamical simulations of single giant planets, and predict the emergent intensity field with radiative transfer. Pressure gradients at planet-carved gaps, spiral wakes and vortices bear strong kinematic counterparts. The iso-velocity contours in the CO(2-1) line centroids vo reveal large-scale perturbations, corresponding to abrupt transitions from below sub-Keplerian to super-Keplerian rotation along with radial and vertical flows. The increase in line optical depth at the edge of the gap also modulates vo, but this is a mild effect compared to the dynamical imprint of the planet-disc interaction. The large-scale deviations from the Keplerian rotation thus allow the planets to be indirectly detected via the first moment maps of molecular gas tracers, at ALMA angular resolutions. The strength of these deviations depends on the mass of the perturber. This initial study paves the way to eventually determine the mass of the planet by comparison with more detailed models.

  20. Individual and Interactive Effects of Socio-Ecological Factors on Dengue Fever at Fine Spatial Scale: A Geographical Detector-Based Analysis.

    Science.gov (United States)

    Cao, Zheng; Liu, Tao; Li, Xing; Wang, Jin; Lin, Hualiang; Chen, Lingling; Wu, Zhifeng; Ma, Wenjun

    2017-07-17

    Background : Large spatial heterogeneity was observed in the dengue fever outbreak in Guangzhou in 2014, however, the underlying reasons remain unknown. We examined whether socio-ecological factors affected the spatial distribution and their interactive effects. Methods : Moran's I was applied to first examine the spatial cluster of dengue fever in Guangzhou. Nine socio-ecological factors were chosen to represent the urbanization level, economy, accessibility, environment, and the weather of the 167 townships/streets in Guangzhou, and then the geographical detector was applied to analyze the individual and interactive effects of these factors on the dengue outbreak. Results : Four clusters of dengue fever were identified in Guangzhou in 2014, including one hot spot in the central area of Guangzhou and three cold spots in the suburban districts. For individual effects, the temperature ( q = 0.33) was the dominant factor of dengue fever, followed by precipitation ( q = 0.24), road density ( q = 0.24), and water body area ( q = 0.23). For the interactive effects, the combination of high precipitation, high temperature, and high road density might result in increased dengue fever incidence. Moreover, urban villages might be the dengue fever hot spots. Conclusions : Our study suggests that some socio-ecological factors might either separately or jointly influence the spatial distribution of dengue fever in Guangzhou.