WorldWideScience

Sample records for diverse user community

  1. Supporting Shared Resource Usage for a Diverse User Community: the OSG Experience and Lessons Learned

    International Nuclear Information System (INIS)

    Garzoglio, Gabriele; Levshina, Tanya; Sehgal, Chander; Slyz, Marko; Rynge, Mats

    2012-01-01

    The Open Science Grid (OSG) supports a diverse community of new and existing users in adopting and making effective use of the Distributed High Throughput Computing (DHTC) model. The LHC user community has deep local support within the experiments. For other smaller communities and individual users the OSG provides consulting and technical services through the User Support area. We describe these sometimes successful and sometimes not so successful experiences and analyze lessons learned that are helping us improve our services. The services offered include forums to enable shared learning and mutual support, tutorials and documentation for new technology, and troubleshooting of problematic or systemic failure modes. For new communities and users, we bootstrap their use of the distributed high throughput computing technologies and resources available on the OSG by following a phased approach. We first adapt the application and run a small production campaign on a subset of “friendly” sites. Only then do we move the user to run full production campaigns across the many remote sites on the OSG, adding to the community resources up to hundreds of thousands of CPU hours per day. This scaling up generates new challenges – like no determinism in the time to job completion, and diverse errors due to the heterogeneity of the configurations and environments – so some attention is needed to get good results. We cover recent experiences with image simulation for the Large Synoptic Survey Telescope (LSST), small-file large volume data movement for the Dark Energy Survey (DES), civil engineering simulation with the Network for Earthquake Engineering Simulation (NEES), and accelerator modeling with the Electron Ion Collider group at BNL. We will categorize and analyze the use cases and describe how our processes are evolving based on lessons learned.

  2. Community Identity and User Engagement in a Multi-Community Landscape.

    Science.gov (United States)

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

    2017-05-01

    A community's identity defines and shapes its internal dynamics. Our current understanding of this interplay is mostly limited to glimpses gathered from isolated studies of individual communities. In this work we provide a systematic exploration of the nature of this relation across a wide variety of online communities. To this end we introduce a quantitative, language-based typology reflecting two key aspects of a community's identity: how distinctive , and how temporally dynamic it is. By mapping almost 300 Reddit communities into the landscape induced by this typology, we reveal regularities in how patterns of user engagement vary with the characteristics of a community. Our results suggest that the way new and existing users engage with a community depends strongly and systematically on the nature of the collective identity it fosters, in ways that are highly consequential to community maintainers. For example, communities with distinctive and highly dynamic identities are more likely to retain their users. However, such niche communities also exhibit much larger acculturation gaps between existing users and newcomers, which potentially hinder the integration of the latter. More generally, our methodology reveals differences in how various social phenomena manifest across communities, and shows that structuring the multi-community landscape can lead to a better understanding of the systematic nature of this diversity.

  3. Popularity and user diversity of online objects

    Science.gov (United States)

    Wang, Jia-Hua; Guo, Qiang; Yang, Kai; Zhang, Yi-Lu; Han, Jingti; Liu, Jian-Guo

    2016-11-01

    The popularity has been widely used to describe the object property of online user-object bipartite networks regardless of the user characteristics. In this paper, we introduce a measurement namely user diversity to measure diversity of users who select or rate one type of objects by using the information entropy. We empirically calculate the user diversity of objects with specific degree for both MovieLens and Diggs data sets. The results indicate that more types of users select normal-degree objects than those who select large-degree and small-degree objects. Furthermore, small-degree objects are usually selected by large-degree users while large-degree objects are usually selected by small-degree users. Moreover, we define 15% objects of smallest degrees as unpopular objects and 10% ones of largest degrees as popular objects. The timestamp is introduced to help further analyze the evolution of user diversity of popular objects and unpopular objects. The dynamic analysis shows that as objects become popular gradually, they are more likely accepted by small-degree users but lose attention among the large-degree users.

  4. Profiting from innovative user communities

    DEFF Research Database (Denmark)

    Jeppesen, Lars Bo

    Modding - the modification of existing products by consumers - is increasingly exploited by manufacturers to enhance product development and sales. In the computer games industry modding has evolved into a development model in which users act as unpaid `complementors' to manufacturers' product pl......, a manufacturer can incorporate and commercialize the best complements found in the user communities. Keywords: innovation, modding, user communities, software platform, business model. JEL code(s): L21; L23; O31; O32...... platforms. This article explains how manufacturers can profit from their abilities to organize and facilitate a process of innovation by user communities and capture the value of the innovations produced in such communities. When managed strategically, two distinct, but not mutually exclusive business...... models appear from the production of user complements: firstly, a manufacturer can let the (free) user complements `drift' in the user communities, where they increase the value to consumers of owning the given platform and thus can be expected to generate increased platform sales, and secondly...

  5. EMI New User Communities

    CERN Document Server

    Riedel, M

    2013-01-01

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

  6. A user's guide to functional diversity indices

    OpenAIRE

    Schleuter, D.; Daufresne, M.; Massol, F.; Argillier, C.

    2010-01-01

    Functional diversity is the diversity of species traits in ecosystems. This concept is increasingly used in ecological research, yet its formal definition and measurements are currently under discussion. As the overall behaviour and consistency of functional diversity indices have not been described so far, the novice user risks choosing an inaccurate index or a set of redundant indices to represent functional diversity. In our study we closely examine functional diversity indices to clari...

  7. Community-aware user profile enrichment in folksonomy.

    Science.gov (United States)

    Xie, Haoran; Li, Qing; Mao, Xudong; Li, Xiaodong; Cai, Yi; Rao, Yanghui

    2014-10-01

    In the era of big data, collaborative tagging (a.k.a. folksonomy) systems have proliferated as a consequence of the growth of Web 2.0 communities. Constructing user profiles from folksonomy systems is useful for many applications such as personalized search and recommender systems. The identification of latent user communities is one way to better understand and meet user needs. The behavior of users is highly influenced by the behavior of their neighbors or community members, and this can be utilized in constructing user profiles. However, conventional user profiling techniques often encounter data sparsity problems as data from a single user is insufficient to build a powerful profile. Hence, in this paper we propose a method of enriching user profiles based on latent user communities in folksonomy data. Specifically, the proposed approach contains four sub-processes: (i) tag-based user profiles are extracted from a folksonomy tripartite graph; (ii) a multi-faceted folksonomy graph is constructed by integrating tag and image affinity subgraphs with the folksonomy tripartite graph; (iii) random walk distance is used to unify various relationships and measure user similarities; (iv) a novel prototype-based clustering method based on user similarities is used to identify user communities, which are further used to enrich the extracted user profiles. To evaluate the proposed method, we conducted experiments using a public dataset, the results of which show that our approach outperforms previous ones in user profile enrichment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Why firm-established user communities work for innovation

    DEFF Research Database (Denmark)

    Jeppesen, Lars Bo; Frederiksen, Lars

    Studies of the sources of innovations have recognized that many innovations are developedby users. However, the fact that firms employ communities of users to strengthen their innovationprocess has not yet received much attention. In firm-established user communities users freely revealinnovation...... by selling them to all users. We study the key personal attributes of the individuals responsiblefor innovations and the creation of value in this organizational context, namely the innovative users, toexplain why firm-established user communities work. Analyzing data derived from a web...

  9. Why firm-established user communities work for innovation

    DEFF Research Database (Denmark)

    Jeppesen, Lars Bo; Frederiksen, Lars

    2004-01-01

    Studies of the sources of innovations have recognized that many innovations are developedby users. However, the fact that firms employ communities of users to strengthen their innovationprocess has not yet received much attention. In firm-established user communities users freely revealinnovation...... by selling them to all users. We study the key personal attributes of the individuals responsiblefor innovations and the creation of value in this organizational context, namely the innovative users, toexplain why firm-established user communities work. Analyzing data derived from a web...

  10. Exploiting Multi-user Diversity and Multi-hop Diversity in Dual-hop Broadcast Channels

    KAUST Repository

    Zafar, Ammar

    2013-05-21

    We propose joint user-and-hop scheduling over dual-hop block-fading broadcast channels in order to exploit multi-user diversity gains and multi-hop diversity gains all together. To achieve this objective, the first and second hops are scheduled opportunistically based on the channel state information. The joint scheduling problem is formulated as maximizing the weighted sum of the long term achievable rates of the users under a stability constraint, which means that in the long term the rate received by the relay should equal the rate transmitted by it, in addition to power constraints. We show that this problem is equivalent to a single-hop broadcast channel by treating the source as a virtual user with an optimal weight that maintains the stability constraint. We show how to obtain the source weight either off-line based on channel statistics or on real-time based on channel measurements. Furthermore, we consider special cases including the maximum sum-rate scheduler and the proportional fair scheduler. We also show how to extend the scheme into one that allows multiple user scheduling via superposition coding with successive decoding. Numerical results demonstrate that our proposed joint scheduling scheme enlarges the rate region as compared to scheduling schemes that exploit the diversity gains partially.

  11. Multiuser switched diversity scheduling systems with per-user threshold

    KAUST Repository

    Nam, Haewoon

    2010-05-01

    A multiuser switched diversity scheduling scheme with per-user feedback threshold is proposed and analyzed in this paper. The conventional multiuser switched diversity scheduling scheme uses a single feedback threshold for every user, where the threshold is a function of the average signal-to-noise ratios (SNRs) of the users as well as the number of users involved in the scheduling process. The proposed scheme, however, constructs a sequence of feedback thresholds instead of a single feedback threshold such that each user compares its channel quality with the corresponding feedback threshold in the sequence. Numerical and simulation results show that thanks to the flexibility of threshold selection, where a potentially different threshold can be used for each user, the proposed scheme provides a higher system capacity than that for the conventional scheme. © 2006 IEEE.

  12. Can Dissimilar Users Contribute to Accuracy and Diversity of Personalized Recommendation?

    Science.gov (United States)

    Zeng, Wei; Shang, Ming-Sheng; Zhang, Qian-Ming; Lü, Linyuan; Zhou, Tao

    Recommender systems are becoming a popular and important set of personalization techniques that assist individual users with navigating through the rapidly growing amount of information. A good recommender system should be able to not only find out the objects preferred by users, but also help users in discovering their personalized tastes. The former corresponds to high accuracy of the recommendation, while the latter to high diversity. A big challenge is to design an algorithm that provides both highly accurate and diverse recommendation. Traditional recommendation algorithms only take into account the contributions of similar users, thus, they tend to recommend popular items for users ignoring the diversity of recommendations. In this paper, we propose a recommendation algorithm by considering both the effects of similar and dissimilar users under the framework of collaborative filtering. Extensive analyses on three datasets, namely MovieLens, Netflix and Amazon, show that our method performs much better than the standard collaborative filtering algorithm for both accuracy and diversity.

  13. Exploring users motivation in innovation communities

    OpenAIRE

    Ståhlbröst, Anna; Bergvall-Kåreborn, Birgitta

    2011-01-01

    A rapid growth of technologies supporting user interaction on the Internet, such as social networking sites and other virtual communities, can be seen today. These virtual communities have been shown to be of great value to companies that want to involve users in their innovation processes. However, in order to guide organisations on how to utilise their innovation intermediary communities, more knowledge is needed regarding who they are and their motivational drivers for participating in a c...

  14. How the Use of Remote Sensing is Transferred to Diverse User Communities Through Capacity Building at Columbia University

    Science.gov (United States)

    Ceccato, P.; Bell, M. A.; Mantilla, G.; Thomson, M. C.

    2012-12-01

    This presentation will provide an overview of capacity-building activities developed by the International Research Institute for Climate and Society to help diverse stakeholder communities use remote sensing to monitor climate and environmental factors that influence public health, natural disasters and food security. Teaching at a graduate level at Columbia University, at summer institutes and in counties, we developed training modules and case studies on how to combine remote sensing data to monitor precipitation, temperature, vegetation, and water bodies with climate information and field data (e.g. fires, infectious disease incidence, Desert Locusts) to 1) understand the relationship between climate, environmental factors and specific challenges to development and 2) provide methodologies and tools to forecast and better manage the problems. At Columbia University, we have developed a graduate course that provides the practical and theoretical foundations for the application of remote sensing techniques to the identification and monitoring of environmental change. We use the IRI Data Library, an online tool, to i) manage diverse data, ii) visualize data, iii) analyze remote sensing images and iii) combine data from different sources (e.g., fires, public health, natural disasters, agriculture). The IRI Data Library tool allows the users to analyze on-line climatic and environmental factors in relation to particular problems at various space and time scales. A Summer Institute on Climate Information for Public Health, first developed in 2008, has brought together experts from the public health and climate communities at the IRI to learn how to integrate climate and environmental factors with public health issues. In countries and regions, we also provide training for climate and public health working professionals in Madagascar, Ethiopia, Eritrea, Colombia and the Mercosur Region (including Uruguay, Paraguay, Brazil and Argentina).

  15. Analysis and visualization of social user communities

    Directory of Open Access Journals (Sweden)

    Daniel LÓPEZ SÁNCHEZ

    2016-06-01

    Full Text Available In this paper, a novel framework for social user clustering is proposed. Given a current controversial political topic, the Louvain Modularity algorithm is used to detect communities of users sharing the same political preferences. The political alignment of a set of users is labeled manually by a human expert and then the quality of the community detection is evaluated against this gold standard. In the last section, we propose a novel force-directed graph algorithm to generate a visual representation of the detected communities.   

  16. IT User Community Survey

    CERN Document Server

    Peter Jones (IT-CDA-WF)

    2016-01-01

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

  17. Functional & phylogenetic diversity of copepod communities

    Science.gov (United States)

    Benedetti, F.; Ayata, S. D.; Blanco-Bercial, L.; Cornils, A.; Guilhaumon, F.

    2016-02-01

    The diversity of natural communities is classically estimated through species identification (taxonomic diversity) but can also be estimated from the ecological functions performed by the species (functional diversity), or from the phylogenetic relationships among them (phylogenetic diversity). Estimating functional diversity requires the definition of specific functional traits, i.e., phenotypic characteristics that impact fitness and are relevant to ecosystem functioning. Estimating phylogenetic diversity requires the description of phylogenetic relationships, for instance by using molecular tools. In the present study, we focused on the functional and phylogenetic diversity of copepod surface communities in the Mediterranean Sea. First, we implemented a specific trait database for the most commonly-sampled and abundant copepod species of the Mediterranean Sea. Our database includes 191 species, described by seven traits encompassing diverse ecological functions: minimal and maximal body length, trophic group, feeding type, spawning strategy, diel vertical migration and vertical habitat. Clustering analysis in the functional trait space revealed that Mediterranean copepods can be gathered into groups that have different ecological roles. Second, we reconstructed a phylogenetic tree using the available sequences of 18S rRNA. Our tree included 154 of the analyzed Mediterranean copepod species. We used these two datasets to describe the functional and phylogenetic diversity of copepod surface communities in the Mediterranean Sea. The replacement component (turn-over) and the species richness difference component (nestedness) of the beta diversity indices were identified. Finally, by comparing various and complementary aspects of plankton diversity (taxonomic, functional, and phylogenetic diversity) we were able to gain a better understanding of the relationships among the zooplankton community, biodiversity, ecosystem function, and environmental forcing.

  18. Low Functional β-Diversity Despite High Taxonomic β-Diversity among Tropical Estuarine Fish Communities

    Science.gov (United States)

    Villéger, Sébastien; Miranda, Julia Ramos; Hernandez, Domingo Flores; Mouillot, David

    2012-01-01

    The concept of β-diversity, defined as dissimilarity among communities, has been widely used to investigate biodiversity patterns and community assembly rules. However, in ecosystems with high taxonomic β-diversity, due to marked environmental gradients, the level of functional β-diversity among communities is largely overlooked while it may reveal processes shaping community structure. Here, decomposing biodiversity indices into α (local) and γ (regional) components, we estimated taxonomic and functional β-diversity among tropical estuarine fish communities, through space and time. We found extremely low functional β-diversity values among fish communities (diversities, α and γ functional diversities were very close to the minimal value. These patterns were caused by two dominant functional groups which maintained a similar functional structure over space and time, despite the strong dissimilarity in taxonomic structure along environmental gradients. Our findings suggest that taxonomic and functional β-diversity deserve to be quantified simultaneously since these two facets can show contrasting patterns and the differences can in turn shed light on community assembly rules. PMID:22792395

  19. User-led innovation in civic energy communities

    NARCIS (Netherlands)

    de Vries, Gerben; Boon, Wouter; Peine, A.

    2016-01-01

    Building on user and grassroots innovation literature, we explore user innovations in five Dutch civic energy communities. Less attention has been paid to the interplay of social, symbolic and technological innovations that seems to be at the heart of many civic energy communities. In this paper, we

  20. Identifying influential user communities on the social network

    Science.gov (United States)

    Hu, Weishu; Gong, Zhiguo; Hou U, Leong; Guo, Jingzhi

    2015-10-01

    Nowadays social network services have been popularly used in electronic commerce systems. Users on the social network can develop different relationships based on their common interests and activities. In order to promote the business, it is interesting to explore hidden relationships among users developed on the social network. Such knowledge can be used to locate target users for different advertisements and to provide effective product recommendations. In this paper, we define and study a novel community detection problem that is to discover the hidden community structure in large social networks based on their common interests. We observe that the users typically pay more attention to those users who share similar interests, which enable a way to partition the users into different communities according to their common interests. We propose two algorithms to detect influential communities using common interests in large social networks efficiently and effectively. We conduct our experimental evaluation using a data set from Epinions, which demonstrates that our method achieves 4-11.8% accuracy improvement over the state-of-the-art method.

  1. Diversity spurs diversification in ecological communities

    Science.gov (United States)

    Calcagno, Vincent; Jarne, Philippe; Loreau, Michel; Mouquet, Nicolas; David, Patrice

    2017-06-01

    Diversity is a fundamental, yet threatened, property of ecological systems. The idea that diversity can itself favour diversification, in an autocatalytic process, is very appealing but remains controversial. Here, we study a generalized model of ecological communities and investigate how the level of initial diversity influences the possibility of evolutionary diversification. We show that even simple models of intra- and inter-specific ecological interactions can predict a positive effect of diversity on diversification: adaptive radiations may require a threshold number of species before kicking-off. We call this phenomenon DDAR (diversity-dependent adaptive radiations) and identify mathematically two distinct pathways connecting diversity to diversification, involving character displacement and the positive diversity-productivity relationship. Our results may explain observed delays in adaptive radiations at the macroscale and diversification patterns reported in experimental microbial communities, and shed new light on the dynamics of ecological diversity, the diversity-dependence of diversification rates, and the consequences of biodiversity loss.

  2. Diversity spurs diversification in ecological communities.

    Science.gov (United States)

    Calcagno, Vincent; Jarne, Philippe; Loreau, Michel; Mouquet, Nicolas; David, Patrice

    2017-06-09

    Diversity is a fundamental, yet threatened, property of ecological systems. The idea that diversity can itself favour diversification, in an autocatalytic process, is very appealing but remains controversial. Here, we study a generalized model of ecological communities and investigate how the level of initial diversity influences the possibility of evolutionary diversification. We show that even simple models of intra- and inter-specific ecological interactions can predict a positive effect of diversity on diversification: adaptive radiations may require a threshold number of species before kicking-off. We call this phenomenon DDAR (diversity-dependent adaptive radiations) and identify mathematically two distinct pathways connecting diversity to diversification, involving character displacement and the positive diversity-productivity relationship. Our results may explain observed delays in adaptive radiations at the macroscale and diversification patterns reported in experimental microbial communities, and shed new light on the dynamics of ecological diversity, the diversity-dependence of diversification rates, and the consequences of biodiversity loss.

  3. The Relationship between Cultural Diversity and User Needs in Virtual Reference Services

    Science.gov (United States)

    Shachaf, Pnina; Snyder, Mary

    2007-01-01

    While the racial diversity of academic library users continues to grow, research on the effects of this diversity remains scarce. This study looks at similarities and differences between non-traditional Caucasian and African American library users through content analysis of ninety-four virtual reference transactions.

  4. SPECIES DIVERSITY AND STABILITY OF BIRD COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Matsyura M.V.

    2011-12-01

    Full Text Available When comparing the suggested stability indicators, we obtained statistically significant correlations for indicators of annual stability of species and total number and standard deviation of the logarithm of the number. Annual Stability Index can be applied with a high degree of reliability as a characteristic of the averaged structure of the community and its pyramid of abundances. The results of correlation analysis confirm our assumptions about the correlation between stability over the years and indices of species diversity and relative uniformity.The final task of the study was to create a mathematical model of stability, where the independent variables are the indices of species diversity. The calculation of these indices allows forecasting birds’ community stability. According to the result of multiple regression for the indicators of diversity and stability of the breeding birds’ community highest correlation coefficients were obtained fro Shannon index and Simpson's dominance Index.Community stability could be determined by its overall species diversity. When considering the stability of community its diversity should be considered as a combination of uniformity of their total number and number of species. The most suitable predictors for the community stability were the nonparametric index of dominance and information-statistical indices, since they considered simultaneously evenness and richness. The community stability is subject of the complexity of its internal communications pattern.

  5. Genetic diversity within a dominant plant outweighs plant species diversity in structuring an arthropod community.

    Science.gov (United States)

    Crawford, Kerri M; Rudgers, Jennifer A

    2013-05-01

    Plant biodiversity is being lost at a rapid rate. This has spurred much interest in elucidating the consequences of this loss for higher trophic levels. Experimental tests have shown that both plant species diversity and genetic diversity within a plant species can influence arthropod community structure. However, the majority of these studies have been conducted in separate systems, so their relative importance is currently unresolved. Furthermore, potential interactions between the two levels of diversity, which likely occur in natural systems, have not been investigated. To clarify these issues, we conducted three experiments in a freshwater sand dune ecosystem. We (1) independently manipulated plant species diversity, (2) independently manipulated genetic diversity within the dominant plant species, Ammophila breviligulata, and (3) jointly manipulated genetic diversity within the dominant plant and species diversity. We found that genetic diversity within the dominant plant species, Ammophila breviligulata, more strongly influenced arthropod communities than plant species diversity, but this effect was dependent on the presence of other species. In species mixtures, A. breviligulata genetic diversity altered overall arthropod community composition, and arthropod richness and abundance peaked at the highest level of genetic diversity. Positive nonadditive effects of diversity were detected, suggesting that arthropods respond to emergent properties of diverse plant communities. However, in the independent manipulations where A. breviligulata was alone, effects of genetic diversity were weaker, with only arthropod richness responding. In contrast, plant species diversity only influenced arthropods when A. breviligulata was absent, and then only influenced herbivore abundance. In addition to showing that genetic diversity within a dominant plant species can have large effects on arthropod community composition, these results suggest that understanding how species

  6. Diverse Perspectives on Inclusive School Communities

    Science.gov (United States)

    Tsokova, Diana; Tarr, Jane

    2012-01-01

    What is an inclusive school community? How do stakeholders perceive their roles and responsibilities towards inclusive school communities? How can school communities become more inclusive through engagement with individual perspectives? "Diverse Perspectives on Inclusive School Communities" captures and presents the voices of a wide…

  7. Emergence of communities and diversity in social networks.

    Science.gov (United States)

    Han, Xiao; Cao, Shinan; Shen, Zhesi; Zhang, Boyu; Wang, Wen-Xu; Cressman, Ross; Stanley, H Eugene

    2017-03-14

    Communities are common in complex networks and play a significant role in the functioning of social, biological, economic, and technological systems. Despite widespread interest in detecting community structures in complex networks and exploring the effect of communities on collective dynamics, a deep understanding of the emergence and prevalence of communities in social networks is still lacking. Addressing this fundamental problem is of paramount importance in understanding, predicting, and controlling a variety of collective behaviors in society. An elusive question is how communities with common internal properties arise in social networks with great individual diversity. Here, we answer this question using the ultimatum game, which has been a paradigm for characterizing altruism and fairness. We experimentally show that stable local communities with different internal agreements emerge spontaneously and induce social diversity into networks, which is in sharp contrast to populations with random interactions. Diverse communities and social norms come from the interaction between responders with inherent heterogeneous demands and rational proposers via local connections, where the former eventually become the community leaders. This result indicates that networks are significant in the emergence and stabilization of communities and social diversity. Our experimental results also provide valuable information about strategies for developing network models and theories of evolutionary games and social dynamics.

  8. Testing Universal Design of a Public Media Website with Diverse Users.

    Science.gov (United States)

    Chen, Weiqin; Kessel, Siri; Sanderson, Norun C; Tatara, Naoe

    2016-01-01

    Testing with users can identify more issues than other testing methods. Many researchers have argued for the importance of user testing in Universal Design. However, testing Universal Design with diverse users poses many challenges. In this paper we will share our experience with testing the Universal Design of a public media website with real users. We discuss the challenges faced and lessons learned in the process.

  9. Evolution of the EOSDIS Data User Communities

    Science.gov (United States)

    Krupp, B. M.; Murphy, K. J.; Wanchoo, L.; Chang, H.

    2011-12-01

    Since NASA's EOS Terra platform began operations in early FY2000, data centers affiliated with the EOS Data and Information System (EOSDIS) have distributed over 12.8 Petabytes (PB) and 1.2 billion files of data to over 2.3 million distinct users through the end of FY2010. Metrics on data ingest, archive, and distribution have been collected throughout the EOS era by different automated systems. The functionality of these systems has improved over the years, allowing more types of metrics analyses to be made with greater precision. The ESDIS Metrics System (EMS) replaced the earlier ESDIS Data Gathering and Reporting System (EDGRS) in FY2005. Since then it has collected increasingly more accurate information about data users obtaining products from the many EOSDIS data centers. The information allows characterization of the various EOSDIS user communities, and enables studies of how these communities have changed over time. User information obtained when an order is placed, or products are downloaded from a data center's FTP site, include the user's IP host (or IP address) and email address. The EMS system is able to resolve most IP addresses to specific domains. Combined with science discipline information associated with the data products themselves, users and data distributions to them can be characterized in a number of ways, including by countries, disciplines (e.g. Atmosphere, Ocean, Land), and [most readily for the United States] affiliations (Government, Education, Non-profit, or Commercial). The purpose of this investigation is to analyze patterns of data distributions within the different user groups mentioned above and to trace their evolution over time. Results show, for example, that the number of foreign users has increased greatly over the years, as has the number of countries receiving EOSDIS data products. These kinds of studies can be very useful to the various data centers. By gaining a better understanding of how their user communities are

  10. Reconcilable differences? Human diversity, cultural relativity, and sense of community.

    Science.gov (United States)

    Townley, Greg; Kloos, Bret; Green, Eric P; Franco, Margarita M

    2011-03-01

    Sense of community (SOC) is one of the most widely used and studied constructs in community psychology. As proposed by Sarason in (The Psychological sense of community: prospects for a community psychology, Jossey-Bass, San Francisco, 1974), SOC represents the strength of bonding among community members. It is a valuable component of community life, and it has been linked to positive mental health outcomes, citizen participation, and community connectedness. However, promotion of SOC can become problematic in community psychology praxis when it conflicts with other core values proposed to define the field, namely values of human diversity, cultural relativity, and heterogeneity of experience and perspective. Several commentators have noted that promotion of SOC can conflict with multicultural diversity because it tends to emphasize group member similarity and appears to be higher in homogeneous communities. In this paper, we introduce the idea of a community-diversity dialectic as part of praxis and research in community psychology. We argue that systematic consideration of cultural psychology perspectives can guide efforts to address a community-diversity dialectic and revise SOC formulations that ultimately will invigorate community research and action. We provide a working agenda for addressing this dialectic, proposing that systematic consideration of the creative tension between SOC and diversity can be beneficial to community psychology.

  11. Diversity in a Hidden Community: Tardiagrades in Lichens.

    Science.gov (United States)

    Shofner, Marcia; Vodopich, Darrell

    1993-01-01

    Describes an interesting field experiment examining the distribution and diversity of a single community using lichens and the animals living in them. Combining field experience and laboratory work reveals not only the biology of some unusual organisms, but also community ecology and diversity. (PR)

  12. On Low-Complexity Full-diversity Detection In Multi-User MIMO Multiple-Access Channels

    KAUST Repository

    Ismail, Amr

    2014-01-28

    Multiple-input multiple-output (MIMO) techniques are becoming commonplace in recent wireless communication standards. This newly introduced dimension (i.e., space) can be efficiently used to mitigate the interference in the multi-user MIMO context. In this paper, we focus on the uplink of a MIMO multiple access channel (MAC) where perfect channel state information (CSI) is only available at the destination. We provide new sufficient conditions for a wide range of space-time block codes (STBC)s to achieve full-diversity under partial interference cancellation group decoding (PICGD) with or without successive interference cancellation (SIC) for completely blind users. Interference cancellation (IC) schemes for two and three users are then provided and shown to satisfy the full-diversity criteria. Beside the complexity reduction due to the fact that PICGD enables separate decoding of distinct users without sacrificing the diversity gain, further reduction of the decoding complexity may be obtained. In fact, thanks to the structure of the proposed schemes, the real and imaginary parts of each user\\'s symbols may be decoupled without any loss of performance. Our new IC scheme is shown to outperform recently proposed two-user IC scheme especially for high spectral efficiency while requiring significantly less decoding complexity.

  13. Community and Diversity: Administration in a Democratic Context.

    Science.gov (United States)

    Crow, Gary M.

    1994-01-01

    Defining community politically (as a flexible arena for debating perspectives and achieving purpose) provides different ways to consider diversity. Diversity becomes not an anomaly but an integral part of the community process; conflict is legitimized as appropriate and inevitable in achieving school purposes. Administrators must mediate conflict,…

  14. Multilabel user classification using the community structure of online networks.

    Science.gov (United States)

    Rizos, Georgios; Papadopoulos, Symeon; Kompatsiaris, Yiannis

    2017-01-01

    We study the problem of semi-supervised, multi-label user classification of networked data in the online social platform setting. We propose a framework that combines unsupervised community extraction and supervised, community-based feature weighting before training a classifier. We introduce Approximate Regularized Commute-Time Embedding (ARCTE), an algorithm that projects the users of a social graph onto a latent space, but instead of packing the global structure into a matrix of predefined rank, as many spectral and neural representation learning methods do, it extracts local communities for all users in the graph in order to learn a sparse embedding. To this end, we employ an improvement of personalized PageRank algorithms for searching locally in each user's graph structure. Then, we perform supervised community feature weighting in order to boost the importance of highly predictive communities. We assess our method performance on the problem of user classification by performing an extensive comparative study among various recent methods based on graph embeddings. The comparison shows that ARCTE significantly outperforms the competition in almost all cases, achieving up to 35% relative improvement compared to the second best competing method in terms of F1-score.

  15. Multilabel user classification using the community structure of online networks.

    Directory of Open Access Journals (Sweden)

    Georgios Rizos

    Full Text Available We study the problem of semi-supervised, multi-label user classification of networked data in the online social platform setting. We propose a framework that combines unsupervised community extraction and supervised, community-based feature weighting before training a classifier. We introduce Approximate Regularized Commute-Time Embedding (ARCTE, an algorithm that projects the users of a social graph onto a latent space, but instead of packing the global structure into a matrix of predefined rank, as many spectral and neural representation learning methods do, it extracts local communities for all users in the graph in order to learn a sparse embedding. To this end, we employ an improvement of personalized PageRank algorithms for searching locally in each user's graph structure. Then, we perform supervised community feature weighting in order to boost the importance of highly predictive communities. We assess our method performance on the problem of user classification by performing an extensive comparative study among various recent methods based on graph embeddings. The comparison shows that ARCTE significantly outperforms the competition in almost all cases, achieving up to 35% relative improvement compared to the second best competing method in terms of F1-score.

  16. Exploring user behavior and needs in Q & A communities

    OpenAIRE

    Choudhury, Smitashree; Alani, Harith

    2014-01-01

    One of the difficult challenges of any knowledge centric online community is to sustain the momentum of knowledge sharing and knowledge creation effort by its members through various means. This requires a clearer understanding of user needs that drive community members to contribute, engage and stay loyal to the community. In this paper, we explore the applicability of Abraham Maslow’s theory (1943) to understand user behavior and their latent needs using Exploratory Factor analysis. Results...

  17. Performance Analysis of Diversity-Controlled Multi-User Superposition Transmission for 5G Wireless Networks.

    Science.gov (United States)

    Yeom, Jeong Seon; Chu, Eunmi; Jung, Bang Chul; Jin, Hu

    2018-02-10

    In this paper, we propose a novel low-complexity multi-user superposition transmission (MUST) technique for 5G downlink networks, which allows multiple cell-edge users to be multiplexed with a single cell-center user. We call the proposed technique diversity-controlled MUST technique since the cell-center user enjoys the frequency diversity effect via signal repetition over multiple orthogonal frequency division multiplexing (OFDM) sub-carriers. We assume that a base station is equipped with a single antenna but users are equipped with multiple antennas. In addition, we assume that the quadrature phase shift keying (QPSK) modulation is used for users. We mathematically analyze the bit error rate (BER) of both cell-edge users and cell-center users, which is the first theoretical result in the literature to the best of our knowledge. The mathematical analysis is validated through extensive link-level simulations.

  18. On Low-Complexity Full-diversity Detection In Multi-User MIMO Multiple-Access Channels

    KAUST Repository

    Ismail, Amr; Alouini, Mohamed-Slim

    2014-01-01

    Multiple-input multiple-output (MIMO) techniques are becoming commonplace in recent wireless communication standards. This newly introduced dimension (i.e., space) can be efficiently used to mitigate the interference in the multi-user MIMO context. In this paper, we focus on the uplink of a MIMO multiple access channel (MAC) where perfect channel state information (CSI) is only available at the destination. We provide new sufficient conditions for a wide range of space-time block codes (STBC)s to achieve full-diversity under partial interference cancellation group decoding (PICGD) with or without successive interference cancellation (SIC) for completely blind users. Interference cancellation (IC) schemes for two and three users are then provided and shown to satisfy the full-diversity criteria. Beside the complexity reduction due to the fact that PICGD enables separate decoding of distinct users without sacrificing the diversity gain, further reduction of the decoding complexity may be obtained. In fact, thanks to the structure of the proposed schemes, the real and imaginary parts of each user's symbols may be decoupled without any loss of performance. Our new IC scheme is shown to outperform recently proposed two-user IC scheme especially for high spectral efficiency while requiring significantly less decoding complexity.

  19. User community development for the space transportation system/Skylab

    Science.gov (United States)

    Archer, J. L.; Beauchamp, N. A.

    1974-01-01

    The New User Function plan for identifying beneficial uses of space is described. Critical issues such as funding, manpower, and protection of user proprietary rights are discussed along with common barriers which impede the development of a user community. Studies for developing methodologies of identifying new users and uses of the space transportation system are included.

  20. Increasing Diversity in Emerging Non-religious Communities

    Directory of Open Access Journals (Sweden)

    Christopher Hassall

    2014-12-01

    Full Text Available Contemporary growth in non-religious populations has given rise to novel communities with unique perspectives on social issues. We describe a study of diversity within speakers at conferences organised by and attended by the atheist community. We analyse trends in diversity of 630 speakers, corresponding to 1223 speaking slots at 48 conferences conducted for the purpose of discussing or espousing non-religious views over the period 2003–2014. Diversity among speakers (defined using multivariate statistics in terms of the representation of women and non-white people increased significantly over time during the period studied. This broadening participation may have arisen from interventions to address issues of representation or may simply reflect a generational shift in the demographics of the community. However, on-going problems with data collection and the imbalance in the social cost of identifying as non-religious between different social groups continue to impede efforts to reduce barriers to equality within this growing movement.

  1. Data latency and the user community

    Science.gov (United States)

    Escobar, V. M.; Brown, M. E.; Carroll, M.

    2013-12-01

    The community using NASA Earth science observations in applications has grown significantly, with increasing sophistication to serve national interests. The National Research Council's Earth Science Decadal Survey report stated that the planning for applied and operational considerations in the missions should accompany the acquisition of new knowledge about Earth (NRC, 2007). This directive has made product applications at NASA an integral part of converting the data collected into actionable knowledge that can be used to inform policy. However, successfully bridging scientific research with operational decision making in different application areas requires looking into user data requirements and operational needs. This study was conducted to determine how users are incorporating NASA data into applications and operational processes. The approach included a review of published materials, direct interviews with mission representatives, and an online professional review, which was distributed to over 6000 individuals. We provide a complete description of the findings with definitions and explanations of what goes into measuring latency as well as how users and applications utilize NASA data products. We identified 3 classes of users: operational (need data in 3 hours or less), near real time (need data within a day of acquisition), and scientific users (need highest quality data, time independent). We also determined that most users with applications are interested in specific types of products that may come from multiple missions. These users will take the observations when they are available, however the observations may have additional applications value if they are available either by a certain time of day or within a period of time after acquisition. NASA has supported the need for access to low latency data on an ad-hoc basis and more substantively in stand-alone systems such as the MODIS Rapid Response system and more recently with LANCE. The increased level

  2. Assessment of Soil Moisture Data Requirements by the Potential SMAP Data User Community: Review of SMAP Mission User Community

    Science.gov (United States)

    Brown, Molly E.; Escobar, Vanessa M.

    2013-01-01

    NASA's Soil Moisture Active and Passive (SMAP) mission is planned for launch in October 2014 and will provide global measurements of soil moisture and freeze thaw state. The project is driven by both basic research and applied science goals. Understanding how application driven end-users will apply SMAP data, prior to the satellite's launch, is an important goal of NASA's applied science program and SMAP mission success. Because SMAP data are unique, there are no direct proxy data sets that can be used in research and operational studies to determine how the data will interact with existing processes. The objective of this study is to solicit data requirements, accuracy needs, and current understanding of the SMAP mission from the potential user community. This study showed that the data to be provided by the SMAP mission did substantially meet the user community needs. Although there was a broad distribution of requirements stated, the SMAP mission fit within these requirements.

  3. Understanding User Behavioral Patterns in Open Knowledge Communities

    Science.gov (United States)

    Yang, Xianmin; Song, Shuqiang; Zhao, Xinshuo; Yu, Shengquan

    2018-01-01

    Open knowledge communities (OKCs) have become popular in the era of knowledge economy. This study aimed to explore how users collaboratively create and share knowledge in OKCs. In particular, this research identified the behavior distribution and behavioral patterns of users by conducting frequency distribution and lag sequential analyses. Some…

  4. User roles and contributions during the new product development process in collaborative innovation communities.

    Science.gov (United States)

    Guo, Wei; Zheng, Qing; An, Weijin; Peng, Wei

    2017-09-01

    Collaborative innovation (co-innovation) community emerges as a new product design platform where companies involve users in the new product development (NPD) process. Large numbers of users participate and contribute to the process voluntarily. This exploratory study investigates the heterogeneous roles of users based on a global co-innovation project in online community. Content analysis, social network analysis and cluster method are employed to measure user behaviors, distinguish user roles, and analyze user contributions. The study identifies six user roles that emerge during the NPD process in co-innovation community: project leader, active designer, generalist, communicator, passive designer, and observer. The six user roles differ in their contribution forms and quality. This paper contributes to research on co-innovation in online communities, including design team structure, user roles and their contribution to design task and solution, as well as user value along the process. In addition, the study provides practices guidance on implementing project, attracting users, and designing platform for co-innovation community practitioners. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. It's all relative: ranking the diversity of aquatic bacterial communities.

    Science.gov (United States)

    Shaw, Allison K; Halpern, Aaron L; Beeson, Karen; Tran, Bao; Venter, J Craig; Martiny, Jennifer B H

    2008-09-01

    The study of microbial diversity patterns is hampered by the enormous diversity of microbial communities and the lack of resources to sample them exhaustively. For many questions about richness and evenness, however, one only needs to know the relative order of diversity among samples rather than total diversity. We used 16S libraries from the Global Ocean Survey to investigate the ability of 10 diversity statistics (including rarefaction, non-parametric, parametric, curve extrapolation and diversity indices) to assess the relative diversity of six aquatic bacterial communities. Overall, we found that the statistics yielded remarkably similar rankings of the samples for a given sequence similarity cut-off. This correspondence, despite the different underlying assumptions of the statistics, suggests that diversity statistics are a useful tool for ranking samples of microbial diversity. In addition, sequence similarity cut-off influenced the diversity ranking of the samples, demonstrating that diversity statistics can also be used to detect differences in phylogenetic structure among microbial communities. Finally, a subsampling analysis suggests that further sequencing from these particular clone libraries would not have substantially changed the richness rankings of the samples.

  6. Emotions and Activity Profiles of Influential Users in Product Reviews Communities

    Directory of Open Access Journals (Sweden)

    Dorian eTanase

    2015-11-01

    Full Text Available Viral marketing seeks to maximize the spread of a campaignthrough an online social network, often targeting influential nodes with highcentrality. In this article, we analyze behavioral aspects of influentialusers in trust-based product reviews communities, quantifying emotionalexpression, helpfulness, and user activity level. We focus on two independentproduct review communities, Dooyoo and Epinions, in whichusers can write product reviews and define trust links to filter productrecommendations. Following the patterns of social contagion processes, wemeasure user social influence by means of the k-shell decomposition of trustnetworks. For each of these users, we apply sentiment analysis to extracttheir extent of positive, negative, and neutral emotional expression. Inaddition, we quantify the level of feedback they received in their reviews,the length of their contributions, and their level of activity over theirlifetime in the community. We find that users of both communities exhibit alarge heterogeneity of social influence, and that helpfulness votes and ageare significantly better predictors of the influence of an individual thansentiment. The most active of the analyzed communities shows a particularstructure, in which the inner core of users is qualitatively different fromits periphery in terms of a stronger positive and negative emotionalexpression. These results suggest that both objective and subjective aspectsof reviews are relevant to the communication of subjective experience.

  7. Diverse honeydew-consuming fungal communities associated with scale insects.

    Directory of Open Access Journals (Sweden)

    Manpreet K Dhami

    Full Text Available Sooty mould fungi are ubiquitous, abundant consumers of insect-honeydew that have been little-studied. They form a complex of unrelated fungi that coexist and compete for honeydew, which is a chemically complex resource. In this study, we used scanning electron microscopy in combination with T-RFLP community profiling and ITS-based tag-pyrosequencing to extensively describe the sooty mould community associated with the honeydews of two ecologically important New Zealand coelostomidiid scale insects, Coelostomidia wairoensis and Ultracoelostoma brittini. We tested the influence of host plant on the community composition of associated sooty moulds, and undertook limited analyses to examine the influence of scale insect species and geographic location. We report here a previously unknown degree of fungal diversity present in this complex, with pyrosequencing detecting on average 243 operational taxonomic units across the different sooty mould samples. In contrast, T-RFLP detected only a total of 24 different "species" (unique peaks. Nevertheless, both techniques identified similar patterns of diversity suggesting that either method is appropriate for community profiling. The composition of the microbial community associated with individual scale insect species varied although the differences may in part reflect variation in host preference and site. Scanning electron microscopy visualised an intertwined mass of fungal hyphae and fruiting bodies in near-intact physical condition, but was unable to distinguish between the different fungal communities on a morphological level, highlighting the need for molecular research. The substantial diversity revealed for the first time by pyrosequencing and our inability to identify two-thirds of the diversity to further than the fungal division highlights the significant gap in our knowledge of these fungal groups. This study provides a first extensive look at the community diversity of the fungal community

  8. Dependence and resistance in community mental health care-Negotiations of user participation between staff and users.

    Science.gov (United States)

    Femdal, I; Knutsen, I R

    2017-10-01

    WHAT IS KNOWN ON THE SUBJECT?: Implementation of user participation is described as a change from a paternalistic healthcare system to ideals of democratization where users' voices are heard in relational interplays with health professionals. The ideological shift involves a transition from welfare dependency and professional control towards more active service-user roles with associated rights and responsibilities. A collaborative relationship between users and professionals in mental health services is seen as important by both parties. Nevertheless, the health professionals find it challenging in practice to reorient their roles and to find productive ways to cooperate. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: This study illuminates how user participation is negotiated and involves multiple and shifting subject positions in the collaboration between users and professionals in community mental health care. By taking different positions, the relationship between users and professionals develops through dynamic interaction. This study challenges understandings of equality and implicit "truths" in user participation by illuminating subtle forms of power and dilemmas that arise in user-professional negotiations. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Instead of denying the appearance of power, it is important to question the execution of power in the interplay between users and professionals. Focusing on the negotiation processes between users and professionals is important for increasing reflection on and improving understanding of the dynamic in collaboration and speech. By focusing on negotiations, power can be used in productive ways in user-professional relationships. Introduction Implementation of user participation is considered important in today's mental health care. Research shows, however, that user participation lacks clarity and provokes uncertainty regarding shifting roles. Aim To investigate negotiation of user participation in a microstudy of

  9. Bridging the Dialectic: Diversity, Psychological Sense of Community, and Inclusion.

    Science.gov (United States)

    Brodsky, Anne E

    2017-06-01

    Although, there are many times when P/SOC and diversity appear in opposition, I argue that this conflict is not inherent to the concepts or their joint value, but to social contexts in which they are enacted in real life. The primary values of community psychology-building and supporting positive communities, social change, and social justice within a framework that recognizes the centrality of diversity, culture, inclusion, power, and privilege-actually bind diversity and community together. Thus, we can bridge this seeming dialectic through deeper reflection about the real and intended meaning, operationalization, and application of these two terms, and a reliance on the central values of our field. © Society for Community Research and Action 2017.

  10. Firm and user community collaboration: A complex love story

    DEFF Research Database (Denmark)

    Dragsdahl Lauritzen, Ghita; La Cour, Anders

    The purpose of this thesis is to develop a comprehensive framework that describes the dynamic relationship between firms and user communities. To understand the implications of collaboration, from the relation between users and firms rather than from their individual properties, this thesis urges...

  11. Factors Correlated with the Interactional Diversity of Community College Students

    Science.gov (United States)

    Jones, Willis A.

    2016-01-01

    This study used data from the Community College Survey of Student Engagement (CCSSE) to examine how student background characteristics, student engagement, and institutional characteristics correlate with the frequency of interactional diversity among community college students. Given the current lack of research on interactional diversity among…

  12. Engaging diverse communities towards climate protection

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, J.; Imran, N. [Blekinge Inst. of Technology, Karlskrona (Sweden)

    2008-07-01

    Engaging urban communities as newcomers towards UN climate change targets is not only good governance but also a way of relating deliberative democracy to the human need of participation. This poster outlines effective multicultural engagement as it relates to strategic sustainable development. The presentation shares the benefits of broadening communication strategies from informing citizens to consultation and empowering diverse communities to participate in the global effort to reduce greenhouse gas emissions.

  13. Full-diversity partial interference cancellation for multi-user wireless relaying networks

    KAUST Repository

    El Astal, M. T O

    2013-12-01

    We focus on the uplink channel of multi-user wireless relaying networks in a coverage extension scenario. The network consists of two users, a single half duplex (HD) relay and a destination, all equipped with multiple antennas. Perfect channel state information (CSI) is assumed to be available exclusively at the receiving nodes (i.e., the relay and the destination) while the users are assumed to be completely blind. The communication through the considered network takes place over two phases. During the first phase, both users send their information concurrently to the relay. The second phase consists of decoding the received data and forwarding it simultaneously to the destination. A transmission scheme that achieves full-diversity under partial interference cancellation (PIC) group decoding is proposed. Unlike many existing schemes, it allows the concurrent transmission in both phases while achieving the full-diversity gain of full time division multiple access (TDMA) transmission regardless of the number of antennas at each node. Numerical comparison with existing schemes in the literature is provided to corroborate our theoretical claims. It is found that our interference cancellation (IC) scheme clearly outperforms existing schemes at the expense of an affordable increase in decoding complexity at both of the relay and destination. © 2013 IEEE.

  14. Full-diversity partial interference cancellation for multi-user wireless relaying networks

    KAUST Repository

    El Astal, M. T O; Ismail, Amr; Alouini, Mohamed-Slim; Olivier, Jan Corné

    2013-01-01

    We focus on the uplink channel of multi-user wireless relaying networks in a coverage extension scenario. The network consists of two users, a single half duplex (HD) relay and a destination, all equipped with multiple antennas. Perfect channel state information (CSI) is assumed to be available exclusively at the receiving nodes (i.e., the relay and the destination) while the users are assumed to be completely blind. The communication through the considered network takes place over two phases. During the first phase, both users send their information concurrently to the relay. The second phase consists of decoding the received data and forwarding it simultaneously to the destination. A transmission scheme that achieves full-diversity under partial interference cancellation (PIC) group decoding is proposed. Unlike many existing schemes, it allows the concurrent transmission in both phases while achieving the full-diversity gain of full time division multiple access (TDMA) transmission regardless of the number of antennas at each node. Numerical comparison with existing schemes in the literature is provided to corroborate our theoretical claims. It is found that our interference cancellation (IC) scheme clearly outperforms existing schemes at the expense of an affordable increase in decoding complexity at both of the relay and destination. © 2013 IEEE.

  15. Emergence of communities and diversity in social networks

    OpenAIRE

    Han, Xiao; Cao, Shinan; Shen, Zhesi; Zhang, Boyu; Wang, Wen-Xu; Cressman, Ross; Stanley, H. Eugene

    2017-01-01

    Understanding how communities emerge is a fundamental problem in social and economic systems. Here, we experimentally explore the emergence of communities in social networks, using the ultimatum game as a paradigm for capturing individual interactions. We find the emergence of diverse communities in static networks is the result of the local interaction between responders with inherent heterogeneity and rational proposers in which the former act as community leaders. In contrast, communities ...

  16. Image Re-Ranking Based on Topic Diversity.

    Science.gov (United States)

    Qian, Xueming; Lu, Dan; Wang, Yaxiong; Zhu, Li; Tang, Yuan Yan; Wang, Meng

    2017-08-01

    Social media sharing Websites allow users to annotate images with free tags, which significantly contribute to the development of the web image retrieval. Tag-based image search is an important method to find images shared by users in social networks. However, how to make the top ranked result relevant and with diversity is challenging. In this paper, we propose a topic diverse ranking approach for tag-based image retrieval with the consideration of promoting the topic coverage performance. First, we construct a tag graph based on the similarity between each tag. Then, the community detection method is conducted to mine the topic community of each tag. After that, inter-community and intra-community ranking are introduced to obtain the final retrieved results. In the inter-community ranking process, an adaptive random walk model is employed to rank the community based on the multi-information of each topic community. Besides, we build an inverted index structure for images to accelerate the searching process. Experimental results on Flickr data set and NUS-Wide data sets show the effectiveness of the proposed approach.

  17. Community placement and reintegration of service users from long ...

    African Journals Online (AJOL)

    Objective: To ascertain community placement and reintegration of service users from long-term mental health care facilities. Method: This study reviewed the progress during 2003 with the alternative placement of a selected candidate group of 27 service users in some of Lifecare's long-term mental health care facilities in ...

  18. On low-complexity full-diversity detection of multi-user space-time coding

    KAUST Repository

    Ismail, Amr

    2013-06-01

    The incorporation of multiple input multiple output (MIMO) schemes in recent wireless communication standards paved the way to exploit the newly introduced dimension (i.e. space) to efficiently cancel the interference without requiring additional resources. In this paper, we focus on multiple input multiple ouitput (MIMO) multiple access channel (MAC) case and we answer the question about whether it is possible to suppress the interference in a MIMO MAC channel for completely blind users while achieving full-diversity with a simplified decoder in the affirmative. In fact, this goal can be attained by employing space-time block codes (STBC)s that achive full-diversity under partial interference cancellation (PIC). We derive sufficient conditions for a wide range of STBCs to achieve full-diversity under PIC group decoding with or without successive interference cancellation (SIC). Based on the provided design criteria we derive an upper-bound on the achievable rate for a class of codes. A two-user MIMO MAC interference cancellation scheme is presented and proved to achieve full-diversity under PIC group decoding. We compare our scheme to existing beamforming schemes with full or limit feedback. © 2013 IEEE.

  19. Visualization of diversity in large multivariate data sets.

    Science.gov (United States)

    Pham, Tuan; Hess, Rob; Ju, Crystal; Zhang, Eugene; Metoyer, Ronald

    2010-01-01

    Understanding the diversity of a set of multivariate objects is an important problem in many domains, including ecology, college admissions, investing, machine learning, and others. However, to date, very little work has been done to help users achieve this kind of understanding. Visual representation is especially appealing for this task because it offers the potential to allow users to efficiently observe the objects of interest in a direct and holistic way. Thus, in this paper, we attempt to formalize the problem of visualizing the diversity of a large (more than 1000 objects), multivariate (more than 5 attributes) data set as one worth deeper investigation by the information visualization community. In doing so, we contribute a precise definition of diversity, a set of requirements for diversity visualizations based on this definition, and a formal user study design intended to evaluate the capacity of a visual representation for communicating diversity information. Our primary contribution, however, is a visual representation, called the Diversity Map, for visualizing diversity. An evaluation of the Diversity Map using our study design shows that users can judge elements of diversity consistently and as or more accurately than when using the only other representation specifically designed to visualize diversity.

  20. Embracing Diversity: The Exploration of User Motivations in Citizen Science Astronomy Projects

    Science.gov (United States)

    Lee, Lo

    2018-06-01

    Online citizen science projects ask members of the public to donate spare time on their personal computers to process large datasets. A critical challenge for these projects is volunteer recruitment and retention. Many of these projects use Berkeley Open Infrastructure for Network Computing (BOINC), a piece of middleware, to support their operations. This poster analyzes volunteer motivations in two large, BOINC-based astronomy projects, Einstein@Home and Milkyway@Home. Volunteer opinions are addressed to assess whether and how competitive elements, such as credit and ranking systems, motivate volunteers. Findings from a study of project volunteers, comprising surveys (n=2,031) and follow-up interviews (n=21), show that altruism is the main incentive for participation because volunteers consider scientific research to be critical for humans. Multiple interviewees also revealed a passion for extrinsic motivations, i.e. those that involve recognition from other people, such as opportunities to become co-authors of publications or to earn financial benefits. Credit and ranking systems motivate nearly half of interviewees. By analyzing user motivations in astronomical BOINC projects, this research provides scientists with deeper understandings about volunteer communities and various types of volunteers. Building on these findings, scientists can develop different strategies, for example, awarding volunteers badges, to recruit and retain diverse volunteers, and thus enhance long-term user participation in astronomical BOINC projects.

  1. Functional diversity in plant communities: Theory and analysis ...

    African Journals Online (AJOL)

    Plant functional diversity in community has become a key point in ecology studies recently. The development of species functional diversity was reviewed in the present work. Based on the former original research papers and reviews, we discussed the concept and connotation and put forward a new definition of functional ...

  2. Online extremism and the communities that sustain it: Detecting the ISIS supporting community on Twitter

    Science.gov (United States)

    Joseph, Kenneth; Carley, Kathleen M.

    2017-01-01

    The Islamic State of Iraq and ash-Sham (ISIS) continues to use social media as an essential element of its campaign to motivate support. On Twitter, ISIS’ unique ability to leverage unaffiliated sympathizers that simply retweet propaganda has been identified as a primary mechanism in their success in motivating both recruitment and “lone wolf” attacks. The present work explores a large community of Twitter users whose activity supports ISIS propaganda diffusion in varying degrees. Within this ISIS supporting community, we observe a diverse range of actor types, including fighters, propagandists, recruiters, religious scholars, and unaffiliated sympathizers. The interaction between these users offers unique insight into the people and narratives critical to ISIS’ sustainment. In their entirety, we refer to this diverse set of users as an online extremist community or OEC. We present Iterative Vertex Clustering and Classification (IVCC), a scalable analytic approach for OEC detection in annotated heterogeneous networks, and provide an illustrative case study of an online community of over 22,000 Twitter users whose online behavior directly advocates support for ISIS or contibutes to the group’s propaganda dissemination through retweets. PMID:29194446

  3. Supporting National User Communities at NERSC and NCAR

    Energy Technology Data Exchange (ETDEWEB)

    Killeen, Timothy L.; Simon, Horst D.

    2006-05-16

    The National Energy Research Scientific Computing Center(NERSC) and the National Center for Atmospheric Research (NCAR) are twocomputing centers that have traditionally supported large national usercommunities. Both centers have developed responsive approaches to supportthese user communities and their changing needs, providing end-to-endcomputing solutions. In this report we provide a short overview of thestrategies used at our centers in supporting our scientific users, withan emphasis on some examples of effective programs and futureneeds.

  4. Diversity within Diversity” - Exploring Connections between Community, Participation and Citizenship

    Directory of Open Access Journals (Sweden)

    Pedro D. Ferreira

    2012-09-01

    Full Text Available Even if recently the notions of citizenship and community have become buzzwords of very positive connotation, significant tensions underlie any ofthem: between homogeneity and difference, belonging and diversity,inclusion and exclusion and, more recently, between freedom and security.Real communities are places of cooperation and mutual recognition as muchas they are places of inevitable conflict, social control and exclusion.Following an ecological and contextual perspective, and a relationaldefinition of community, concepts such as sense of community and socialcapital are explored. An analysis of citizen’s participation in theircommunities illustrates significant dimensions of participation: power,dialogue, initiative, formality, pluralism and time. The discussion considershow these dimensions might contribute to making community organizationsturn into 'schools of democracy' (de Tocqueville 2000, and illustrates thispotential with young migrants, as long as the diversity of diverse migrantgroups is not only recognized but furthered.

  5. Creating an Integrated Community-Wide Effort to Enhance Diversity in the Geosciences

    Science.gov (United States)

    Manduca, C. A.; Weingroff, M.

    2001-05-01

    Supporting the development and sustenance of a diverse geoscience workforce and improving Earth system education for the full diversity of students are important goals for our community. There are numerous established programs and many new efforts beginning. However, these efforts can become more powerful if dissemination of opportunities, effective practices, and web-based resources enable synergies to develop throughout our community. The Digital Library for Earth System Education (DLESE; www.dlese.org) has developed a working group and a website to support these goals. The DLESE Diversity Working Group provides an open, virtual community for those interested in enhancing diversity in the geosciences. The working group has focused its initial effort on 1) creating a geoscience community engaged in supporting increased diversity that builds on and is integrated with work taking place in other venues; 2) developing a web resource designed to engage and support members of underrepresented groups in learning about the Earth; and 3) assisting in enhancing DLESE collections and services to better support learning experiences of students from underrepresented groups. You are invited to join the working group and participate in these efforts. The DLESE diversity website provides a mechanism for sharing information and resources. Serving as a community database, the website provides a structure in which community members can post announcements of opportunities, information on programs, and links to resources and services. Information currently available on the site includes links to professional society activities; mentoring opportunities; grant, fellowship, employment, and internship opportunities for students and educators; information on teaching students from underrepresented groups; and professional development opportunities of high interest to members of underrepresented groups. These tools provide a starting point for developing a community wide effort to enhance

  6. Trait diversity promotes stability of community dynamics

    DEFF Research Database (Denmark)

    Zhang, Lai; Thygesen, Uffe Høgsbro; Knudsen, Kim

    2013-01-01

    body size. The dynamic properties of the models are described by a stability analysis of equilibrium solutions and by the non-equilibrium dynamics. We find that the introduction of trait diversity expands the set of parameters for which the equilibrium is stable and, if the community is unstable, makes....... The analysis is performed by comparing the properties of two size spectrum models. The first model considers all individuals as belonging to the same “average” species, i.e., without a description of diversity. The second model introduces diversity by further considering individuals by a trait, here asymptotic...

  7. Design of an online health-promoting community: negotiating user community needs with public health goals and service capabilities.

    Science.gov (United States)

    Ekberg, Joakim; Timpka, Toomas; Angbratt, Marianne; Frank, Linda; Norén, Anna-Maria; Hedin, Lena; Andersen, Emelie; Gursky, Elin A; Gäre, Boel Andersson

    2013-07-04

    An online health-promoting community (OHPC) has the potential to promote health and advance new means of dialogue between public health representatives and the general public. The aim of this study was to examine what aspects of an OHPC that are critical for satisfying the needs of the user community and public health goals and service capabilities. Community-based participatory research methods were used for data collection and analysis, and participatory design principles to develop a case study OHPC for adolescents. Qualitative data from adolescents on health appraisals and perspectives on health information were collected in a Swedish health service region and classified into categories of user health information exchange needs. A composite design rationale for the OHPC was completed by linking the identified user needs, user-derived requirements, and technical and organizational systems solutions. Conflicts between end-user requirements and organizational goals and resources were identified. The most prominent health information needs were associated to food, exercise, and well-being. The assessment of the design rationale document and prototype in light of the regional public health goals and service capabilities showed that compromises were needed to resolve conflicts involving the management of organizational resources and responsibilities. The users wanted to discuss health issues with health experts having little time to set aside to the OHPC and it was unclear who should set the norms for the online discussions. OHPCs can be designed to satisfy both the needs of user communities and public health goals and service capabilities. Compromises are needed to resolve conflicts between users' needs to discuss health issues with domain experts and the management of resources and responsibilities in public health organizations.

  8. Reconciling Diverse Communities through Language Policy Practices in Malaysia

    Directory of Open Access Journals (Sweden)

    Ain Nadzimah Abdullah

    2012-11-01

    Full Text Available Malaysia is an example of a diverse nation with communities facing multiplicities in religions, languages, linguistic practices and cultural beliefs. These multiplicities and polarities need to be understood and managed in order to maintain harmony and unity in this multilingual and multicultural nation. Malaysia, therefore, has to strategize and build up paths that would lead to a solid foundation of trust and cohesiveness among its citizens. This paper seeks to achieve a better and clearer understanding of Malaysian language policies and the relationships in linguistic practices that are seen to contribute to the reconciliation among diverse communities. The paper investigates the language phenomenon through a survey questionnaire that would give information about the relative emphases given to the use of the various languages, and perceptions about issues pertaining to language maintenance. Data reveal diversities in language use in relation to ethnicity and the reconciliations that emerge from these diversities. The reconciliation is an adopted move towards a more united and inclusive community creating “oneness” within multi-ethnic, multi-lingual and multi-cultural Malaysia. The results are also linked to the current program for transformation of Malaysian society under the context of a mission for unity.

  9. On the Use of Diversity Measures in Longitudinal Sequencing Studies of Microbial Communities.

    Science.gov (United States)

    Wagner, Brandie D; Grunwald, Gary K; Zerbe, Gary O; Mikulich-Gilbertson, Susan K; Robertson, Charles E; Zemanick, Edith T; Harris, J Kirk

    2018-01-01

    Identification of the majority of organisms present in human-associated microbial communities is feasible with the advent of high throughput sequencing technology. As substantial variability in microbiota communities is seen across subjects, the use of longitudinal study designs is important to better understand variation of the microbiome within individual subjects. Complex study designs with longitudinal sample collection require analytic approaches to account for this additional source of variability. A common approach to assessing community changes is to evaluate the change in alpha diversity (the variety and abundance of organisms in a community) over time. However, there are several commonly used alpha diversity measures and the use of different measures can result in different estimates of magnitude of change and different inferences. It has recently been proposed that diversity profile curves are useful for clarifying these differences, and may provide a more complete picture of the community structure. However, it is unclear how to utilize these curves when interest is in evaluating changes in community structure over time. We propose the use of a bi-exponential function in a longitudinal model that accounts for repeated measures on each subject to compare diversity profiles over time. Furthermore, it is possible that no change in alpha diversity (single community/sample) may be observed despite the presence of a highly divergent community composition. Thus, it is also important to use a beta diversity measure (similarity between multiple communities/samples) that captures changes in community composition. Ecological methods developed to evaluate temporal turnover have currently only been applied to investigate changes of a single community over time. We illustrate the extension of this approach to multiple communities of interest (i.e., subjects) by modeling the beta diversity measure over time. With this approach, a rate of change in community

  10. Leveraging Community to Promote Diversity and Inclusion within the IceCube Collaboration

    Science.gov (United States)

    Knackert, J.

    2017-12-01

    The IceCube Collaboration is an international research collaboration working to advance the field of particle astrophysics. It is comprised of more than 300 scientists, engineers, students, and support staff at 48 institutions in 12 countries. IceCube recognizes the value of increased diversity within STEM fields and is committed to improving this situation both within the collaboration and more broadly. The collaboration has dedicated a community manager to help coordinate and promote these efforts and has established a diversity task force as an internal resource and advising body. Here we will discuss how existing community structure was utilized to establish and maintain a focus on diversity within the collaboration. We will discuss methods for getting community members interested, informed, and invested, while helping them better understand the benefits associated with increased STEM diversity. We will also highlight the advantages of building a team of advocates within a community and the impact these individuals can have both internally and beyond. This work has been informed by the American Association for the Advancement of Science's inaugural cohort of the Community Engagement Fellows Program. The author has made the submission on behalf of the IceCube Collaboration Diversity Task Force.

  11. Local Plant Diversity Across Multiple Habitats Supports a Diverse Wild Bee Community in Pennsylvania Apple Orchards.

    Science.gov (United States)

    Kammerer, Melanie A; Biddinger, David J; Rajotte, Edwin G; Mortensen, David A

    2016-02-01

    Wild pollinators supply essential, historically undervalued pollination services to crops and other flowering plant communities with great potential to ensure agricultural production against the loss of heavily relied upon managed pollinators. Local plant communities provision wild bees with crucial floral and nesting resources, but the distribution of floristic diversity among habitat types in North American agricultural landscapes and its effect on pollinators are diverse and poorly understood, especially in orchard systems. We documented floristic diversity in typical mid-Atlantic commercial apple (Malus domestica Borkh.) orchards including the forest and orchard-forest edge ("edge") habitats surrounding orchards in a heterogeneous landscape in south-central Pennsylvania, USA. We also assessed the correlation between plant richness and orchard pollinator communities. In this apple production region, edge habitats are the most species rich, supporting 146 out of 202 plant species recorded in our survey. Plant species richness in the orchard and edge habitats were significant predictors of bee species richness and abundance in the orchard, as well as landscape area of the forest and edge habitats. Both the quantity and quality of forest and edges close to orchards play a significant role in provisioning a diverse wild bee community in this agroecosystem. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Understanding Motivations and User Interests as Antecedents for Different Interaction Forms in Online Communities

    DEFF Research Database (Denmark)

    Jacobsen, Lina; Sørensen, Bjarne Taulo; Tudoran, Ana Alina

    This study contributes to the understanding of online user communities as a potential source of innovation. That would require an interest from users in interacting in such communities. In order to establish interaction, users must provide as well as consume information. However, depending...... on the innovation task, one may be more important than the other. It is therefore important to understand, how companies can increase user willingness to engage in these different interaction forms. This study investigates the influence of various motivation factors and user interests on intention to provide...... or consume information in online food communities. A survey was conducted among 1009 respondents followed by analysis based on Structural Equation Modelling. Results revealed the effect of motivation factors to be stronger than basic consumer interests indicating that companies can influence the intended...

  13. Community structure and diversity of macrobenthic invertebrates in ...

    African Journals Online (AJOL)

    Macrobenthic invertebrates' community structure and diversity in relation to ... Analysis of variance (ANOVA) revealed that there were significant difference ... invertebrates' species distribution and some measured environmental variables.

  14. Perspectives on distributed computing : thirty people, four user types, and the distributed computing user experience.

    Energy Technology Data Exchange (ETDEWEB)

    Childers, L.; Liming, L.; Foster, I.; Mathematics and Computer Science; Univ. of Chicago

    2008-10-15

    ; (2) A method for characterizing users according to their technology interactions, and identification of four user types among the interviewees using the method; (3) Four profiles that highlight points of commonality and diversity in each user type; (4) Recommendations for technology developers and future studies; (5) A description of the interview protocol and overall study methodology; (6) An anonymized list of the interviewees; and (7) Interview writeups and summary data. The interview summaries in Section 3 and transcripts in Appendix D illustrate the value of distributed computing software--and Globus in particular--to scientific enterprises. They also document opportunities to make these tools still more useful both to current users and to new communities. We aim our recommendations at developers who intend their software to be used and reused in many applications. (This kind of software is often referred to as 'middleware.') Our two core recommendations are as follows. First, it is essential for middleware developers to understand and explicitly manage the multiple user products in which their software components are used. We must avoid making assumptions about the commonality of these products and, instead, study and account for their diversity. Second, middleware developers should engage in different ways with different kinds of users. Having identified four general user types in Section 4, we provide specific ideas for how to engage them in Section 5.

  15. NASA EOSDIS Enabling Science by Improving User Knowledge

    Science.gov (United States)

    Lindsay, F. E.; Brennan, J.; Blumenfeld, J.

    2016-12-01

    NASA's Earth Observing System Data and Information System (EOSDIS) has been a central component of the NASA Earth observation program since the 1990's. The data collected by NASA's remote sensing instruments, airborne platforms and field campaigns represent a significant public investment in Earth science research. EOSDIS provides free and open access of these data to a diverse end-user community worldwide. Over time the EOSDIS data user community has grown substantially in both number and in the diversity of their needs. Commensurate with this growth, there also have been substantial changes in internet-based technologies and the expectation of users demanding more sophisticated EOSDIS information products describing, highlighting and providing insight to our vast data collections. To meet these increased expectations and to more fully engage our users, EOSDIS is evolving our use of traditional forms of purely static methods of public engagement such as stand-alone text and imagery toward more immersive and interactive forms of communications. This paper highlights and elucidates the methods and forms used by EOSDIS in this emerging world of dynamic and interactive media. Lessons learned and the impacts of applying these newer methods are explained and include several examples from our current efforts. These examples include interactive, on-line webinars focusing on data discovery and access (including tool usage), informal and informative `data chats' with data experts across our EOSDIS community, and profiles of scientists, researchers, and managers actively using EOSDIS data. Our efforts also include improved conference and meeting interactions with data users through the ability to use EOSDIS data interactively during hyperwall talks and the EOSDIS Worldview data visualization and exploration client. The suite of internet-based, interactive capabilities and technologies has allowed EOSDIS to expand our user community by making the data and applications from

  16. Biolog for the determination of diversity in microbial communities

    African Journals Online (AJOL)

    drinie

    2002-01-01

    Jan 1, 2002 ... be related to the functional diversity of the species present in the community. ... The hypothesis is that the more substrates utilised, the higher the diversity, due to the collective action of individual species. Any one organism will not necessarily utilise all the ..... biofouling control in industrial water systems.

  17. [Species, functional, structural diversity of typical plant communities and their responses to environmental factors in Miao Archipelago, China.

    Science.gov (United States)

    Zheng, Li Ting; Su, Tian; Liu, Xiang Yu; Yin, Fang; Guo, Chao; Tuo, Bin; Yan, En Rong

    2018-02-01

    Island vegetation plays an important role in biodiversity research across the world. The study of plant diversity in island is helpful for understanding the mechanism of plant diversity maintenance under land-sea interaction. Here, four typical plant communities (Quercus acutissima community, Robinia pseudoacacia community, Pinus thunbergii community and Vitex negundo community) in Miao Archipelago were selected to examine the species, functional and structural diversities and their responses to environmental factors at the community scale by using species diversity indices, functional diversity indices, as well as structural diversity indices. The results showed that the species richness and Rao index of P. thunbergii community was higher than that of Q. acutissima community and R. pseudoacacia community, but the structural diversity was lower. The species diversity and structural diversity of V. Negundo shrub were lower than that of forest community, but the functional diversity was higher than some forest communities. The relationship between the diversity of typical plant communities in island area illustrated a significant positive correlation between species richness with Rao index and tree height diversity, however the correlation with functional evenness was significantly negative. The structural diversity and functional evenness were determined by slope with negative and positive relationships, respectively. Functional heterogeneity, functional divergence and species diversity were affected largely by soil physical and chemical properties, displaying the positive relationship with soil bulk density and soil total carbon content, and a negative relationship with soil water content. In conclusion, diversity pattern of plant community in Miao Archipelago reflected not only the characteristics in mainland vegetation but also the special nature of the sea island.

  18. Ignored fungal community in activated sludge wastewater treatment plants: diversity and altitudinal characteristics.

    Science.gov (United States)

    Niu, Lihua; Li, Yi; Xu, Lingling; Wang, Peifang; Zhang, Wenlong; Wang, Chao; Cai, Wei; Wang, Linqiong

    2017-02-01

    Fungi are important contributors to the various functions of activated sludge wastewater treatment plants (WWTPs); however, the diversity and geographic characteristics of fungal populations have remained vastly unexplored. Here, quantitative polymerase chain reaction and 454 pyrosequencing were combined to investigate the abundance and diversity of the activated sludge fungal communities from 18 full-scale municipal WWTPs in China. Phylogenetic taxonomy revealed that the members of the fungal communities were assigned to 7 phyla and 195 genera. Ascomycota and Basidiomycota were the most abundant phyla, dominated by Pluteus, Wickerhamiella, and Penicillium. Twenty-three fungal genera, accounting for 50.1 % of the total reads, were shared by 18 WWTPs and constituted a core fungal community. The fungal communities presented similar community diversity but different community structures across the WWTPs. Significant distance decay relationships were observed for the dissimilarity in fungal community structure and altitudinal distance between WWTPs. Additionally, the community evenness increased from 0.25 to 0.7 as the altitude increased. Dissolved oxygen and the C/N ratio were determined to be the most dominant contributors to the variation in fungal community structure via redundancy analysis. The observed data demonstrated the diverse occurrence of fungal species and gave a marked view of fungal community characteristics based on the previously unexplored fungal communities in activated sludge WWTPs.

  19. Looking to the Future: Communicating with an expanding cryospheric user community

    Science.gov (United States)

    Gergely, K.; Scott, D.; Booker, L.

    2009-12-01

    The National Snow and Ice Data Center (NSIDC) at the University of Colorado is known for its customer service. Through the User Services Office (USO) NSIDC provides end-to-end data support with timely, friendly, and professional assistance. This service includes expertise in selecting, obtaining, and handling of data, as well as the dissemination of information related to NSIDC’s cryospheric data and information. This dissemination happens across many mediums, such as email, newsletters, and Web-published data documentation. With surveys like the American Customer Service Index, we are learning more and more about what the user’s informational needs are, and beginning to anticipate what the user's needs might be in the future. In this presentation, we will examine the current USO processes for communicating with our user community, and explore how social networking tools, such as Twitter, Blogging, or Facebook may enhance the overall user experience. We will assess a communication approach that combines mainstream and emerging technologies in order to maintain a high standard of customer service with an expanding cryospheric user community.

  20. Nitrogen addition, not initial phylogenetic diversity, increases litter decomposition by fungal communities

    Directory of Open Access Journals (Sweden)

    Anthony Stuart Amend

    2015-02-01

    Full Text Available Fungi play a critical role in the degradation of organic matter. Because different combinations of fungi result in different rates of decomposition, determining how climate change will affect microbial composition and function is fundamental to predicting future environments. Fungal response to global change is patterned by genetic relatedness, resulting in communities with comparatively low phylogenetic diversity. This may have important implications for the functional capacity of disturbed communities if lineages sensitive to disturbance also contain unique traits important for litter decomposition. Here we tested the relationship between phylogenetic diversity and decomposition rates. Leaf litter fungi were isolated from the field and deployed in microcosms as mock communities along a gradient of initial phylogenetic diversity, while species richness was held constant. Replicate communities were subject to nitrogen fertilization comparable to anthropogenic deposition levels. Carbon mineralization rates were measured over the course of sixty-six days. We found that nitrogen fertilization increased cumulative respiration by 24.8%, and that differences in respiration between fertilized and ambient communities diminished over the course of the experiment. Initial phylogenetic diversity failed to predict respiration rates or their change in response to nitrogen fertilization, and there was no correlation between community similarity and respiration rates. Last, we detected no phylogenetic signal in the contributions of individual isolates to respiration rates. Our results suggest that the degree to which phylogenetic diversity predicts ecosystem function will depend on environmental context.

  1. Low-Complexity Full-Diversity Detection in Two-User MIMO X Channels

    KAUST Repository

    Ismail, Amr

    2014-01-26

    Several interference cancellation (IC) schemes have been recently proposed to suppress multi-user interference for various network configurations (e.g., multiple access and X channels). However, most of these schemes trade-off diversity for implementation complexity or vice-versa. In this paper, we propose a full-diversity interference cancellation scheme in a multiple-input multiple-output (MIMO) X channel with two sources and two destinations while maintaining low decoding complexity. We provide sufficient conditions for a wide range of space-time block codes (STBCs) to achieve full-diversity gain under the so-called partial interference cancellation group decoding (PICGD) in the configuration of interest. A systematic construction is then proposed to achieve full-diversity. The constructed scheme is compared to recently proposed IC scheme in terms of performance and decoding complexity. Our IC scheme outperforms the recently proposed scheme in the case it provides higher transmission rate, while it loses slightly in the case of equal rates. In terms of decoding complexity, both schemes are equivalent.

  2. Low-Complexity Full-Diversity Detection in Two-User MIMO X Channels

    KAUST Repository

    Ismail, Amr; Abediseid, Walid; Alouini, Mohamed-Slim

    2014-01-01

    Several interference cancellation (IC) schemes have been recently proposed to suppress multi-user interference for various network configurations (e.g., multiple access and X channels). However, most of these schemes trade-off diversity for implementation complexity or vice-versa. In this paper, we propose a full-diversity interference cancellation scheme in a multiple-input multiple-output (MIMO) X channel with two sources and two destinations while maintaining low decoding complexity. We provide sufficient conditions for a wide range of space-time block codes (STBCs) to achieve full-diversity gain under the so-called partial interference cancellation group decoding (PICGD) in the configuration of interest. A systematic construction is then proposed to achieve full-diversity. The constructed scheme is compared to recently proposed IC scheme in terms of performance and decoding complexity. Our IC scheme outperforms the recently proposed scheme in the case it provides higher transmission rate, while it loses slightly in the case of equal rates. In terms of decoding complexity, both schemes are equivalent.

  3. Deciphering Diversity Indices for a Better Understanding of Microbial Communities.

    Science.gov (United States)

    Kim, Bo-Ra; Shin, Jiwon; Guevarra, Robin; Lee, Jun Hyung; Kim, Doo Wan; Seol, Kuk-Hwan; Lee, Ju-Hoon; Kim, Hyeun Bum; Isaacson, Richard

    2017-12-28

    The past decades have been a golden era during which great tasks were accomplished in the field of microbiology, including food microbiology. In the past, culture-dependent methods have been the primary choice to investigate bacterial diversity. However, using cultureindependent high-throughput sequencing of 16S rRNA genes has greatly facilitated studies exploring the microbial compositions and dynamics associated with health and diseases. These culture-independent DNA-based studies generate large-scale data sets that describe the microbial composition of a certain niche. Consequently, understanding microbial diversity becomes of greater importance when investigating the composition, function, and dynamics of the microbiota associated with health and diseases. Even though there is no general agreement on which diversity index is the best to use, diversity indices have been used to compare the diversity among samples and between treatments with controls. Tools such as the Shannon- Weaver index and Simpson index can be used to describe population diversity in samples. The purpose of this review is to explain the principles of diversity indices, such as Shannon- Weaver and Simpson, to aid general microbiologists in better understanding bacterial communities. In this review, important questions concerning microbial diversity are addressed. Information from this review should facilitate evidence-based strategies to explore microbial communities.

  4. Housing preferences of Irish forensic mental health service users on moving into the community.

    Science.gov (United States)

    Sweeney, Patricia; Rani Shetty, Shobha

    2013-01-01

    Housing is one of the important services required by forensic mental health service users on reintegration into the community. In the Republic of Ireland, a recent amendment to Section 13 of the Criminal Law Insanity Act (2006) has given the prospect of conditional discharge, which has increased the need for housing among Irish forensic mental health service users. This article reports findings of a qualitative descriptive study aimed to explore the housing preferences of these service users. While identifying and capturing their views, the study also identified the strengths and weaknesses of current housing services from a service user perspective. Data were collected from nine service users using semistructured interviews. Colaizzi's (1978) approach was used to analyze the data. Three themes that emerged from the analysis are as follows: (a) living choices; (b) future considerations; and (c) service users' expectations. Although concerns were raised regarding legislation and policy, service users strongly preferred normal independent living and recommended continued community support, gradual discharge, and community hostels. Findings suggest that service users' expectations may be fulfilled with effective collaboration between forensic mental health service and housing services. This is the first study to be carried out in Ireland that adds a new dimension to the literature on housing policy and service users' perspectives.

  5. Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Nabanita Mukherjee

    2014-12-01

    Full Text Available Public fitness centers and exercise facilities have been implicated as possible sources for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial community residing on the surfaces in these indoor environments is still unknown. In this study, we investigated the overall bacterial ecology of selected fitness centers in a metropolitan area (Memphis, TN, USA utilizing culture-independent pyrosequencing of the 16S rRNA genes. Samples were collected from the skin-contact surfaces (e.g., exercise instruments, floor mats, handrails, etc. within fitness centers. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Proteobacter and Actinobacteria, with a total of 17 bacterial families and 25 bacterial genera. Most of these bacterial genera are of human and environmental origin (including, air, dust, soil, and water. Additionally, we found the presence of some pathogenic or potential pathogenic bacterial genera including Salmonella, Staphylococcus, Klebsiella, and Micrococcus. Staphylococcus was found to be the most prevalent genus. Presence of viable forms of these pathogens elevates risk of exposure of any susceptible individuals. Several factors (including personal hygiene, surface cleaning and disinfection schedules of the facilities may be the reasons for the rich bacterial diversity found in this study. The current finding underscores the need to increase public awareness on the importance of personal hygiene and sanitation for public gym users.

  6. mcaGUI: microbial community analysis R-Graphical User Interface (GUI)

    OpenAIRE

    Copeland, Wade K.; Krishnan, Vandhana; Beck, Daniel; Settles, Matt; Foster, James A.; Cho, Kyu-Chul; Day, Mitch; Hickey, Roxana; Schütte, Ursel M.E.; Zhou, Xia; Williams, Christopher J.; Forney, Larry J.; Abdo, Zaid

    2012-01-01

    Summary: Microbial communities have an important role in natural ecosystems and have an impact on animal and human health. Intuitive graphic and analytical tools that can facilitate the study of these communities are in short supply. This article introduces Microbial Community Analysis GUI, a graphical user interface (GUI) for the R-programming language (R Development Core Team, 2010). With this application, researchers can input aligned and clustered sequence data to create custom abundance ...

  7. Receding Water Line and Interspecific Competition Determines Plant Community Composition and Diversity in Wetlands in Beijing

    Science.gov (United States)

    Wang, Zhengjun; Gong, Huili; Zhang, Jing

    2015-01-01

    Climate and human-induced wetland degradation has accelerated in recent years, not only resulting in reduced ecosystem services but also greatly affecting the composition and diversity of wetland plant communities. To date, the knowledge of the differences in community parameters and their successional trends in degraded wetlands remains scarce. Here based on remote sensing images, geographic information system technology, and statistical methods, we produced a successional gradient map of the Yeyahu Wetland Nature Reserve in Beijing, which has experienced a steady decline in water level in recent decades. In addition, we analyzed community composition and diversity along with each identified gradient. The results showed that community diversity decreases while dominance increases with the progress of succession, with the highest diversity occurring during the early stage of succession. Moreover, the community demonstrates greater similarity among subareas during later successional stages, and the similarity coefficients calculated from the important value (IV) of each species are more accurate. Correlation analysis showed that the impact of soil factors on diversity was not significant at a subarea scale, although these nutrients showed an increasing trend with the community succession. Furthermore, the IVs of the dominant species had a particularly significant impact on diversity, showing a significantly negative correlation with diversity indices and a significantly positive correlation with dominance indices. Further analysis showed that the retreat of water level resulted from sustained drought and local human activities was a major extrinsic driving force resulting in observed differences in the community successional stages, which resulted in differences in community composition and diversity. On the other hand, interspecific competition was the main intrinsic mechanism, which significantly influenced the IVs of the dominant species and community diversity

  8. Plant Community Diversity After Herbicide Control of Spotted Knapweed

    OpenAIRE

    United States Department of Agriculture, Forest Service

    1992-01-01

    Herbicides were applied to four west-central Montana sites with light to moderate spotted knapweed (Centaurea maculosa Lam.) infestations. Althought knapweed suppression was high, 2 years after the spraying the communities were not converted to grass monocultures. No large declines in plant diversity were caused by the herbicides, and small depressions were probably transitory. By the third year, diversity had increased.

  9. Is the contribution of community forest users financially efficient? A household level benefit-cost analysis of community forest management in Nepal

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar Rai

    2016-02-01

    Full Text Available Community forestry in Nepal is considered an exemplary forest management regime. However, the economics behind managing a community forest is not fully studied. This study examines whether the benefits generated from community forest management justify the contributions of forest users. The study is based on a survey of community forest users in Chitwan, Nepal. A household level benefit-cost analysis was performed to quantify and compare the costs and benefits from community forest management. Only direct benefits were included in the analysis. The study shows that older forest user groups derive more benefits to households compared to more recently established ones. The extent of timber harvesting also substantially influences the size of the household benefits. In addition, redistribution of benefits at the household level, in terms of income generating activities and payment for involvement in forest management activities, also enhances household benefits. Sensitivity analysis suggests that the current practice of community forest management enhances the welfare of rural households in this subsistence community. However, this finding is sensitive to assumptions regarding the opportunity cost of time. The study also found that the household costs of community forest management depend upon two factors – the area of community forest and the size of the forest area relative to the number of households.

  10. Species Diversity and Growth Forms in Tropical American Palm Communities

    DEFF Research Database (Denmark)

    Balslev, Henrik; Kahn, Francis; Millán, Betty

    2011-01-01

    To advance our understanding of the processes that govern the assembly of palm communities and the local coexistence of numerous palm species, we here synthesize available information in the literature on species diversity and growth-form composition in palm communities across the Americas. Ameri...

  11. Diversity of arthropod community in transgenic poplar-cotton ecosystems.

    Science.gov (United States)

    Zhang, D J; Lu, Z Y; Liu, J X; Li, C L; Yang, M S

    2015-12-02

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of plain cotton fields in China. Here, we performed a systematic survey of the diversity and population of arthropod communities in four different combination of poplar-cotton eco-systems, including I) non-transgenic poplar and non-transgenic cotton fields; II) non-transgenic poplar and transgenic cotton fields [Bacillus thuringiensis (Bt) cotton]; III) Bt transgenic poplar (high insect resistant strain Pb29) and non-transgenic cotton; and IV) transgenic poplar and transgenic cotton fields, over a period of 3 years. Based on the statistical methods used to investigate community ecology, the effects of transgenic ecosystems on the whole structure of the arthropod community, on the structure of arthropods in the nutritive layer, and on the similarity of arthropod communities were evaluated. The main results were as follows: the transgenic poplar-cotton ecosystem has a stronger inhibitory effect on insect pests and has no impact on the structure of the arthropod community, and therefore, maintains the diversity of the arthropod community. The character index of the community indicated that the structure of the arthropod community of the transgenic poplar-cotton ecosystem was better than that of the poplar-cotton ecosystem, and that system IV had the best structure. As for the abundance of nutritional classes, the transgenic poplar-cotton ecosystem was also better than that of the non-transgenic poplar-cotton ecosystem. The cluster analysis and similarity of arthropod communities between the four different transgenic poplar-cotton ecosystems illustrated that the structure of the arthropod community excelled in the small sample of the transgenic poplar-cotton ecosystems.

  12. Risk-communication capability for public health emergencies varies by community diversity

    Directory of Open Access Journals (Sweden)

    Viswanath Kasisomayajula

    2008-03-01

    Full Text Available Abstract Background Public health emergencies heighten several challenges in risk-communication: providing trustworthy sources of information, reaching marginalized populations, and minimizing fear and public confusion. In emergencies, however, information may not diffuse equally among all social groups, and gaps in knowledge may increase. Such knowledge gaps vary by social structure and the size, socioeconomic status, and diversity of the population. This study explores the relationship between risk-communication capabilities, as perceived by public officials participating in emergency tabletop exercises, and community size and diversity. Findings For each of the three communication functions tested, risk-communication capabilities are perceived to be greater in communities with fewer then 10% of the population speaking a language other than English at home, decreasing as the percentage grows to 20% (ANOVA P ≤ 0.02. With respect to community size, however, we found an N-shaped relationship between perceived risk communication capabilities and population size. Capabilities are perceived highest in the largest communities and lowest in the smallest, but lower in communities with 20,000–49,999 inhabitants compared to those with 2,500–19,999. Conclusion The results of this study suggest the need to factor population diversity into risk communication plans and the need for improved state or regional risk-communication capabilities, especially for communities with limited local capacity.

  13. Nectar-living yeasts of a tropical host plant community: diversity and effects on community-wide floral nectar traits

    Science.gov (United States)

    2017-01-01

    We characterize the diversity of nectar-living yeasts of a tropical host plant community at different hierarchical sampling levels, measure the associations between yeasts and nectariferous plants, and measure the effect of yeasts on nectar traits. Using a series of hierarchically nested sampling units, we extracted nectar from an assemblage of host plants that were representative of the diversity of life forms, flower shapes, and pollinator types in the tropical area of Yucatan, Mexico. Yeasts were isolated from single nectar samples; their DNA was identified, the yeast cell density was estimated, and the sugar composition and concentration of nectar were quantified using HPLC. In contrast to previous studies from temperate regions, the diversity of nectar-living yeasts in the plant community was characterized by a relatively high number of equally common species with low dominance. Analyses predict highly diverse nectar yeast communities in a relatively narrow range of tropical vegetation, suggesting that the diversity of yeasts will increase as the number of sampling units increases at the level of the species, genera, and botanical families of the hosts. Significant associations between specific yeast species and host plants were also detected; the interaction between yeasts and host plants impacted the effect of yeast cell density on nectar sugars. This study provides an overall picture of the diversity of nectar-living yeasts in tropical host plants and suggests that the key factor that affects the community-wide patterns of nectar traits is not nectar chemistry, but rather the type of yeasts interacting with host plants. PMID:28717591

  14. Nectar-living yeasts of a tropical host plant community: diversity and effects on community-wide floral nectar traits

    Directory of Open Access Journals (Sweden)

    Azucena Canto

    2017-07-01

    Full Text Available We characterize the diversity of nectar-living yeasts of a tropical host plant community at different hierarchical sampling levels, measure the associations between yeasts and nectariferous plants, and measure the effect of yeasts on nectar traits. Using a series of hierarchically nested sampling units, we extracted nectar from an assemblage of host plants that were representative of the diversity of life forms, flower shapes, and pollinator types in the tropical area of Yucatan, Mexico. Yeasts were isolated from single nectar samples; their DNA was identified, the yeast cell density was estimated, and the sugar composition and concentration of nectar were quantified using HPLC. In contrast to previous studies from temperate regions, the diversity of nectar-living yeasts in the plant community was characterized by a relatively high number of equally common species with low dominance. Analyses predict highly diverse nectar yeast communities in a relatively narrow range of tropical vegetation, suggesting that the diversity of yeasts will increase as the number of sampling units increases at the level of the species, genera, and botanical families of the hosts. Significant associations between specific yeast species and host plants were also detected; the interaction between yeasts and host plants impacted the effect of yeast cell density on nectar sugars. This study provides an overall picture of the diversity of nectar-living yeasts in tropical host plants and suggests that the key factor that affects the community-wide patterns of nectar traits is not nectar chemistry, but rather the type of yeasts interacting with host plants.

  15. Integrating community perceptions and cultural diversity in social impact assessment in Nigeria

    Energy Technology Data Exchange (ETDEWEB)

    Nzeadibe, Thaddeus Chidi, E-mail: chidi.nzeadibe@unn.edu.ng [Department of Geography, University of Nigeria, 410001 Nsukka (Nigeria); Ajaero, Chukwuedozie Kelechukwu [Demography and Population Studies Programme, The University of Witwatersrand Johannesburg (South Africa); Okonkwo, Emeka Emmanuel; Okpoko, Patrick Uche [Department of Archaeology and Tourism, University of Nigeria, 410001 Nsukka (Nigeria); Akukwe, Thecla Iheoma [Department of Geography, University of Nigeria, 410001 Nsukka (Nigeria); Njoku-Tony, Roseline Feechi [Department of Environmental Technology, Federal University of Technology, Owerri (Nigeria)

    2015-11-15

    The Environmental Impact Assessment (EIA) Act of 1992 aimed to make the environment a central theme in development in Nigeria. Nevertheless, the extent of engagement with local cultures in the Nigerian EIA process is not statutorily guaranteed. While most EIAs in Nigeria have been for oil and gas projects in the Niger Delta, and have focused strongly on the biophysical environment, socio-economic and cultural aspects have remained marginal. The palpable neglect of community perceptions and cultural diversity in social impact assessment (SIA) in this region prone to conflict has tended to alienate the people in the decision-making process. Thus, despite claims to compliance with regulatory requirements for EIAs, and numerous purported sustainable development initiatives by international oil companies (IOCs), the region continues to face multiple sustainability challenges. This paper situates local perceptions and cultural diversity in participatory development and canvasses the integration of community perceptions and cultural diversity into SIA in the Niger Delta region. It is argued that doing this would be critical to ensuring acceptance and success of development actions within the context of local culture while also contributing to sustainable development policy in the region. - Highlights: • Nigeria EIA Act aimed to make the environment central to development in Nigeria. • Engagement with local communities in the process is not statutorily guaranteed. • SIAs in Nigeria neglect community perceptions and cultural diversity. • Article canvasses integrating community perceptions and cultural diversity in SIA. • Local acceptance in context of culture would yield sustainable development outcomes.

  16. Integrating community perceptions and cultural diversity in social impact assessment in Nigeria

    International Nuclear Information System (INIS)

    Nzeadibe, Thaddeus Chidi; Ajaero, Chukwuedozie Kelechukwu; Okonkwo, Emeka Emmanuel; Okpoko, Patrick Uche; Akukwe, Thecla Iheoma; Njoku-Tony, Roseline Feechi

    2015-01-01

    The Environmental Impact Assessment (EIA) Act of 1992 aimed to make the environment a central theme in development in Nigeria. Nevertheless, the extent of engagement with local cultures in the Nigerian EIA process is not statutorily guaranteed. While most EIAs in Nigeria have been for oil and gas projects in the Niger Delta, and have focused strongly on the biophysical environment, socio-economic and cultural aspects have remained marginal. The palpable neglect of community perceptions and cultural diversity in social impact assessment (SIA) in this region prone to conflict has tended to alienate the people in the decision-making process. Thus, despite claims to compliance with regulatory requirements for EIAs, and numerous purported sustainable development initiatives by international oil companies (IOCs), the region continues to face multiple sustainability challenges. This paper situates local perceptions and cultural diversity in participatory development and canvasses the integration of community perceptions and cultural diversity into SIA in the Niger Delta region. It is argued that doing this would be critical to ensuring acceptance and success of development actions within the context of local culture while also contributing to sustainable development policy in the region. - Highlights: • Nigeria EIA Act aimed to make the environment central to development in Nigeria. • Engagement with local communities in the process is not statutorily guaranteed. • SIAs in Nigeria neglect community perceptions and cultural diversity. • Article canvasses integrating community perceptions and cultural diversity in SIA. • Local acceptance in context of culture would yield sustainable development outcomes

  17. Beyond 16S rRNA Community Profiling: Intra-Species Diversity in the Gut Microbiota

    Science.gov (United States)

    Ellegaard, Kirsten M.; Engel, Philipp

    2016-01-01

    Interactions with microbes affect many aspects of animal biology, including immune system development, nutrition and health. In vertebrates, the gut microbiota is dominated by a small subset of phyla, but the species composition within these phyla is typically not conserved. Moreover, several recent studies have shown that bacterial species in the gut are composed of a multitude of strains, which frequently co-exist in their host, and may be host-specific. However, since the study of intra-species diversity is challenging, particularly in the setting of complex, host-associated microbial communities, our current understanding of the distribution, evolution and functional relevance of intra-species diversity in the gut is scarce. In order to unravel how genomic diversity translates into phenotypic diversity, community analyses going beyond 16S rRNA profiling, in combination with experimental approaches, are needed. Recently, the honeybee has emerged as a promising model for studying gut bacterial communities, particularly in terms of strain-level diversity. Unlike most other invertebrates, the honeybee gut is colonized by a remarkably consistent and specific core microbiota, which is dominated by only eight bacterial species. As for the vertebrate gut microbiota, these species are composed of highly diverse strains suggesting that similar evolutionary forces shape gut community structures in vertebrates and social insects. In this review, we outline current knowledge on the evolution and functional relevance of strain diversity within the gut microbiota, including recent insights gained from mammals and other animals such as the honeybee. We discuss methodological approaches and propose possible future avenues for studying strain diversity in complex bacterial communities. PMID:27708630

  18. Distinctive tropical forest variants have unique soil microbial communities, but not always low microbial diversity

    Directory of Open Access Journals (Sweden)

    Binu M Tripathi

    2016-04-01

    Full Text Available There has been little study of whether different variants of tropical rainforest have distinct soil microbial communities and levels of diversity. We compared bacterial and fungal community composition and diversity between primary mixed dipterocarp, secondary mixed dipterocarp, white sand heath, inland heath, and peat swamp forests in Brunei Darussalam, northwest Borneo by analyzing Illumina Miseq sequence data of 16S rRNA gene and ITS1 region. We hypothesized that white sand heath, inland heath and peat swamp forests would show lower microbial diversity and relatively distinct microbial communities (compared to MDF primary and secondary forests due to their distinctive environments. We found that soil properties together with bacterial and fungal communities varied significantly between forest types. Alpha and beta-diversity of bacteria was highest in secondary dipterocarp and white sand heath forests. Also, bacterial alpha diversity was strongly structured by pH, adding another instance of this widespread pattern in nature. The alpha diversity of fungi was equally high in all forest types except peat swamp forest, although fungal beta-diversity was highest in primary and secondary mixed dipterocarp forests. The relative abundance of ectomycorrhizal (EcM fungi varied significantly between forest types, with highest relative abundance observed in MDF primary forest. Overall, our results suggest that the soil bacterial and fungal communities in these forest types are to a certain extent predictable and structured by soil properties, but that diversity is not determined by how distinctive the conditions are. This contrasts with the diversity patterns seen in rainforest trees, where distinctive soil conditions have consistently lower tree diversity.

  19. Disturbance, neutral theory, and patterns of beta diversity in soil communities.

    Science.gov (United States)

    Maaß, Stefanie; Migliorini, Massimo; Rillig, Matthias C; Caruso, Tancredi

    2014-12-01

    Beta diversity describes how local communities within an area or region differ in species composition/abundance. There have been attempts to use changes in beta diversity as a biotic indicator of disturbance, but lack of theory and methodological caveats have hampered progress. We here propose that the neutral theory of biodiversity plus the definition of beta diversity as the total variance of a community matrix provide a suitable, novel, starting point for ecological applications. Observed levels of beta diversity (BD) can be compared to neutral predictions with three possible outcomes: Observed BD equals neutral prediction or is larger (divergence) or smaller (convergence) than the neutral prediction. Disturbance might lead to either divergence or convergence, depending on type and strength. We here apply these ideas to datasets collected on oribatid mites (a key, very diverse soil taxon) under several regimes of disturbances. When disturbance is expected to increase the heterogeneity of soil spatial properties or the sampling strategy encompassed a range of diverging environmental conditions, we observed diverging assemblages. On the contrary, we observed patterns consistent with neutrality when disturbance could determine homogenization of soil properties in space or the sampling strategy encompassed fairly homogeneous areas. With our method, spatial and temporal changes in beta diversity can be directly and easily monitored to detect significant changes in community dynamics, although the method itself cannot inform on underlying mechanisms. However, human-driven disturbances and the spatial scales at which they operate are usually known. In this case, our approach allows the formulation of testable predictions in terms of expected changes in beta diversity, thereby offering a promising monitoring tool.

  20. Sustaining diversity in trait-based models of phytoplankton communities

    Directory of Open Access Journals (Sweden)

    Agostino eMerico

    2014-10-01

    Full Text Available It is well-established that when equilibrium is attained for two species competing for the same limiting resource in a stable, uniform environment, one species will eliminate the other due to competitive exclusion. While competitive exclusion is observed in laboratory experiments and ecological models, the phenomenon seems less common in nature, where static equilibrium is prevented by the fluctuating physical environment and by other factors that constantly change species abundances and the nature of competitive interactions. Trait-based models of phytoplankton communities appear to be useful tools for describing the evolution of large assemblages of species with aggregate group properties such as total biomass, mean trait, and trait variance, the latter representing the functional diversity of the community. Such an approach, however, is limited by the tendency of the trait variance to unrealistically decline to zero over time. This tendency to lose diversity, and therefore adaptive capacity, is typically solved by fixing the variance or by considering exogenous processes such as immigration. Exogenous processes, however, cannot explain the maintenance of adaptive capacity often observed in the closed environment of chemostat experiments. Here we present a new method to sustain diversity in adaptive trait-based models of phytoplankton communities based on a mechanism of trait diffusion through subsequent generations. Our modeling approach can therefore account for endogenous processes such as rapid evolution or transgenerational trait plasticity.

  1. Partitioning of functional and taxonomic diversity in surface-associated microbial communities.

    Science.gov (United States)

    Roth-Schulze, Alexandra J; Zozaya-Valdés, Enrique; Steinberg, Peter D; Thomas, Torsten

    2016-12-01

    Surfaces, including those submerged in the marine environment, are subjected to constant interactions and colonisation by surrounding microorganisms. The principles that determine the assembly of those epibiotic communities are however poorly understood. In this study, we employed a hierarchical design to assess the functionality and diversity of microbial communities on different types of host surfaces (e.g. macroalgae, seagrasses). We found that taxonomic diversity was unique to each type of host, but that the majority of functions (> 95%) could be found in any given surface community, suggesting a high degree of functional redundancy. However, some community functions were enriched on certain surfaces and were related to host-specific properties (e.g. the degradation of specific polysaccharides). Together these observations support a model, whereby communities on surfaces are assembled from guilds of microorganisms with a functionality that is partitioned into general properties for a surface-associated life-style, but also specific features that mediate host-specificity. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. Contrasting diversity patterns of crenarchaeal, bacterial and fungal soil communities in an alpine landscape.

    Directory of Open Access Journals (Sweden)

    Lucie Zinger

    2011-05-01

    Full Text Available The advent of molecular techniques in microbial ecology has aroused interest in gaining an understanding about the spatial distribution of regional pools of soil microbes and the main drivers responsible of these spatial patterns. Here, we assessed the distribution of crenarcheal, bacterial and fungal communities in an alpine landscape displaying high turnover in plant species over short distances. Our aim is to determine the relative contribution of plant species composition, environmental conditions, and geographic isolation on microbial community distribution.Eleven types of habitats that best represent the landscape heterogeneity were investigated. Crenarchaeal, bacterial and fungal communities were described by means of Single Strand Conformation Polymorphism. Relationships between microbial beta diversity patterns were examined by using Bray-Curtis dissimilarities and Principal Coordinate Analyses. Distance-based redundancy analyses and variation partitioning were used to estimate the relative contributions of different drivers on microbial beta diversity. Microbial communities tended to be habitat-specific and did not display significant spatial autocorrelation. Microbial beta diversity correlated with soil pH. Fungal beta-diversity was mainly related to soil organic matter. Though the effect of plant species composition was significant for all microbial groups, it was much stronger for Fungi. In contrast, geographic distances did not have any effect on microbial beta diversity.Microbial communities exhibit non-random spatial patterns of diversity in alpine landscapes. Crenarcheal, bacterial and fungal community turnover is high and associated with plant species composition through different set of soil variables, but is not caused by geographical isolation.

  3. How does a Collaborative Community Affect Diverse Students' Engagement with an Open Source Software Project: A Pedagogical Paradigm

    Science.gov (United States)

    Morgan, Becka S.

    Open Source Software (OSS) communities are homogenous and their lack of diversity is of concern to many within this field. This problem is becoming more pronounced as it is the practice of many technology companies to use OSS participation as a factor in the hiring process, disadvantaging those who are not a part of this community. We should expect that any field would have a population that reflects the general population given no constraints. The constraints within OSS are documented as being a hostile environment for women and minorities to participate in. Additionally OSS communities rely predominately on volunteers to create and maintain source code, documentation, and user interface as well as the organizational structure of the project. The volunteer nature of OSS projects creates a need for an ongoing pool of participants. This research addresses the lack of diversity along with the continual need for new members by developing a pedagogical paradigm that uses a collaborative environment to promote participation in an OSS project by diverse students. This collaborative environment used a Communities of Practice (CoP) framework to design the course, the indicators of which were used to operationalize the collaboration. The outcomes of this course not only benefit the students by providing them with skills necessary to continue participation and experience for getting a job, but also provide a diverse pool of volunteers for the OSS community. This diverse pool shows promise of creating a more diverse culture within OSS. In the development of this pedagogical paradigm this research looked primarily at student's perception of the importance of their group members and mentors provided to guide their participation in and contribution to an OSS community. These elements were used to facilitate the formation of a CoP. Self-efficacy was also used as a measure; an increase in self-efficacy is associated with the successful formation of a CoP. Finally the intent to

  4. Dynamic boundaries of user communities: exploiting synergies rather than managing dilemmas

    DEFF Research Database (Denmark)

    Dragsdahl Lauritzen, Ghita; Salomo, Søren; La Cour, Anders

    2013-01-01

    literature characterises such tensions as dilemmas between competing demands that firms must balance to encourage and benefit from user contributions. This paper brings in a systems theory perspective to show that what is currently described as trade-offs that must be managed are in fact synergies......A large body of literature indicates that innovation not only stems from a firm’s internal investments but also relies on input from external sources. This is also reflected in an increasing interest in user innovation. In particular, users, who increasingly gather in communities, can offer...

  5. Atmospheric data access for the geospatial user community

    Science.gov (United States)

    van de Vegte, John; Som de Cerff, Wim-Jan; van den Oord, Gijsbertus H. J.; Sluiter, Raymond; van der Neut, Ian A.; Plieger, Maarten; van Hees, Richard M.; de Jeu, Richard A. M.; Schaepman, Michael E.; Hoogerwerf, Marc R.; Groot, Nikée E.; Domenico, Ben; Nativi, Stefano; Wilhelmi, Olga V.

    2007-10-01

    Historically the atmospheric and meteorological communities are separate worlds with their own data formats and tools for data handling making sharing of data difficult and cumbersome. On the other hand, these information sources are becoming increasingly of interest outside these communities because of the continuously improving spatial and temporal resolution of e.g. model and satellite data and the interest in historical datasets. New user communities that use geographically based datasets in a cross-domain manner are emerging. This development is supported by the progress made in Geographical Information System (GIS) software. The current GIS software is not yet ready for the wealth of atmospheric data, although the faint outlines of new generation software are already visible: support of HDF, NetCDF and an increasing understanding of temporal issues are only a few of the hints.

  6. Does species diversity limit productivity in natural grassland communities?

    NARCIS (Netherlands)

    Grace, James B.; Anderson, T. Michael; Smith, Melinda D.; Seabloom, Eric; Andelman, Sandy J.; Meche, Gayna; Weiher, Evan; Allain, Larry K.; Jutila, Heli; Sankaran, Mahesh; Knops, Johannes; Ritchie, Mark; Willig, Michael R.

    Theoretical analyses and experimental studies of synthesized assemblages indicate that under particular circumstances species diversity can enhance community productivity through niche complementarity. It remains unclear whether this process has important effects in mature natural ecosystems where

  7. Workforce diversity and community-responsive health-care institutions.

    Science.gov (United States)

    Nivet, Marc A; Berlin, Anne

    2014-01-01

    While the levers for the social determinants of health reside largely outside institutional walls, this does not absolve health professional schools from exercising their influence to improve the communities in which they are located. Fulfilling this charge will require a departure from conventional thinking, particularly when it comes to educating future health professionals. We describe efforts within medical education to transform recruitment, admissions, and classroom environments to emphasize diversity and inclusion. The aim is to cultivate a workforce with the perspectives, aptitudes, and skills needed to fuel community-responsive health-care institutions.

  8. Insights into the diversity of eukaryotes in acid mine drainage biofilm communities.

    Science.gov (United States)

    Baker, Brett J; Tyson, Gene W; Goosherst, Lindsey; Banfield, Jillian F

    2009-04-01

    Microscopic eukaryotes are known to have important ecosystem functions, but their diversity in most environments remains vastly unexplored. Here we analyzed an 18S rRNA gene library from a subsurface iron- and sulfur-oxidizing microbial community growing in highly acidic (pH morphological characterization. Results revealed that the populations vary significantly with the habitat and no group is ubiquitous. Surprisingly, many of the eukaryotic lineages (with the exception of the APC) are closely related to neutrophiles, suggesting that they recently adapted to this extreme environment. Molecular analyses presented here confirm that the number of eukaryotic species associated with the acid mine drainage (AMD) communities is low. This finding is consistent with previous results showing a limited diversity of archaea, bacteria, and viruses in AMD environments and suggests that the environmental pressures and interplay between the members of these communities limit species diversity at all trophic levels.

  9. An outlook of the user support model to educate the users community at the CMS Experiment

    CERN Document Server

    Malik, Sudhir

    2011-01-01

    The CMS (Compact Muon Solenoid) experiment is one of the two large general-purpose particle physics detectors built at the LHC (Large Hadron Collider) at CERN in Geneva, Switzerland. The diverse collaboration combined with a highly distributed computing environment and Petabytes/year of data being collected makes CMS unlike any other High Energy Physics collaborations before. This presents new challenges to educate and bring users, coming from different cultural, linguistics and social backgrounds, up to speed to contribute to the physics analysis. CMS has been able to deal with this new paradigm by deploying a user support structure model that uses collaborative tools to educate about software, computing an physics tools specific to CMS. To carry out the user support mission worldwide, an LHC Physics Centre (LPC) was created few years back at Fermilab as a hub for US physicists. The LPC serves as a "brick and mortar" location for physics excellence for the CMS physicists where graduate and postgraduate scien...

  10. Factors that influence the beta-diversity of spider communities in northwestern Argentinean Grasslands

    Directory of Open Access Journals (Sweden)

    Sandra M. Rodriguez-Artigas

    2016-04-01

    Full Text Available Beta-diversity, defined as spatial replacement in species composition, is crucial to the understanding of how local communities assemble. These changes can be driven by environmental or geographic factors (such as geographic distance, or a combination of the two. Spiders have been shown to be good indicators of environmental quality. Accordingly, spiders are used in this work as model taxa to establish whether there is a decrease in community similarity that corresponds to geographic distance in the grasslands of the Campos & Malezales ecoregion (Corrientes. Furthermore, the influence of climactic factors and local vegetation heterogeneity (environmental factors on assemblage composition was evaluated. Finally, this study evaluated whether the differential dispersal capacity of spider families is a factor that influences their community structure at a regional scale. Spiders were collected with a G-Vac from vegetation in six grassland sites in the Campos & Malezales ecoregion that were separated by a minimum of 13 km. With this data, the impact of alpha-diversity and different environmental variables on the beta-diversity of spider communities was analysed. Likewise, the importance of species replacement and nesting on beta-diversity and their contribution to the regional diversity of spider families with different dispersion capacities was evaluated. The regional and site-specific inventories obtained were complete. The similarity between spider communities declined as the geographic distance between sites increased. Environmental variables also influenced community composition; stochastic events and abiotic forces were the principal intervening factors in assembly structure. The differential dispersal capacity of spider groups also influenced community structure at a regional scale. The regional beta-diversity, as well as species replacement, was greater in high and intermediate vagility spiders; while nesting was greater in spiders with low

  11. Species diversity and drivers of arbuscular mycorrhizal fungal communities in a semi-arid mountain in China

    Directory of Open Access Journals (Sweden)

    He Zhao

    2017-12-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF play an essential role in complex ecosystems. However, the species diversity and composition of AMF communities remain unclear in semi-arid mountains. Further, it is not well understood if the characteristics of AMF community assemblies differ for different habitat types, e.g., agricultural arable land, artificial forest land, natural grassland, and bush/wood land. Here, using the high-throughput technology by Illumina sequencing on the MiSeq platform, we explored the species diversity and composition of soil AMF communities among different habitat types in a semi-arid mountain (Taihang Mountain, Mid-western region of China. Then, we analyzed the effect of nutrient composition and soil texture on AMF community assembly. Our results showed that members of the Glomus genera were predominated in all soil types. The distance-based redundancy analysis indicated that the content of water, available phosphorus, and available potassium were the most crucial geochemical factors that significantly affected AMF communities (p < 0.05. The analysis of the soil texture confirmed that AMF diversity was negatively correlated with soil clay content. The comparison of AMF diversity among the various habitat types revealed that the artificial forest land had the lowest AMF diversity in comparison with other land types. Our findings suggest that there were differences in species diversity and composition of soil AMF communities among different habitat types. These findings shed new light on the characteristics of community structure and drivers of community assembly in AMF in semi-arid mountains, and point to the potential importance of different habitat types on AMF communities.

  12. Mechanisms shaping size structure and functional diversity of phytoplankton communities in the ocean

    Science.gov (United States)

    Acevedo-Trejos, Esteban; Brandt, Gunnar; Bruggeman, Jorn; Merico, Agostino

    2015-01-01

    The factors regulating phytoplankton community composition play a crucial role in structuring aquatic food webs. However, consensus is still lacking about the mechanisms underlying the observed biogeographical differences in cell size composition of phytoplankton communities. Here we use a trait-based model to disentangle these mechanisms in two contrasting regions of the Atlantic Ocean. In our model, the phytoplankton community can self-assemble based on a trade-off emerging from relationships between cell size and (1) nutrient uptake, (2) zooplankton grazing, and (3) phytoplankton sinking. Grazing ‘pushes’ the community towards larger cell sizes, whereas nutrient uptake and sinking ‘pull’ the community towards smaller cell sizes. We find that the stable environmental conditions of the tropics strongly balance these forces leading to persistently small cell sizes and reduced size diversity. In contrast, the seasonality of the temperate region causes the community to regularly reorganize via shifts in species composition and to exhibit, on average, bigger cell sizes and higher size diversity than in the tropics. Our results raise the importance of environmental variability as a key structuring mechanism of plankton communities in the ocean and call for a reassessment of the current understanding of phytoplankton diversity patterns across latitudinal gradients. PMID:25747280

  13. Molecular diversity and tools for deciphering the methanogen community structure and diversity in freshwater sediments.

    Science.gov (United States)

    Chaudhary, Prem Prashant; Brablcová, Lenka; Buriánková, Iva; Rulík, Martin

    2013-09-01

    Methanogenic archaeal communities existing in freshwater sediments are responsible for approximately 50 % of the total global emission of methane. This process contributes significantly to global warming and, hence, necessitates interventional control measures to limit its emission. Unfortunately, the diversity and functional interactions of methanogenic populations occurring in these habitats are yet to be fully characterized. Considering several disadvantages of conventional culture-based methodologies, in recent years, impetus is given to molecular biology approaches to determine the community structure of freshwater sedimentary methanogenic archaea. 16S rRNA and methyl coenzyme M reductase (mcrA) gene-based cloning techniques are the first choice for this purpose. In addition, electrophoresis-based (denaturing gradient gel electrophoresis, temperature gradient gel electrophoresis, and terminal restriction fragment length polymorphism) and quantitative real-time polymerase chain reaction techniques have also found extensive applications. These techniques are highly sensitive, rapid, and reliable as compared to traditional culture-dependent approaches. Molecular diversity studies revealed the dominance of the orders Methanomicrobiales and Methanosarcinales of methanogens in freshwater sediments. The present review discusses in detail the status of the diversity of methanogens and the molecular approaches applied in this area of research.

  14. Influence of soil zinc concentrations on zinc sensitivity and functional diversity of microbial communities

    International Nuclear Information System (INIS)

    Lock, K.; Janssen, C.R.

    2005-01-01

    Pollution induced community tolerance (PICT) is based on the phenomenon that toxic effects reduce survival of the most sensitive organisms, thus increasing community tolerance. Community tolerance for a contaminant is thus a strong indicator for the presence of that contaminant at the level of adverse concentrations. Here we assessed PICT in 11 soils contaminated with zinc runoff from galvanised electricity pylons and 11 reference soils sampled at 10 m distance from these pylons. Using PICT, the influence of background concentration and bioavailability of zinc on zinc sensitivity and functional diversity of microbial communities was assessed. Zinc sensitivity of microbial communities decreased significantly with increasing zinc concentrations in pore water and calcium chloride extracted fraction while no significant relationship was found with total zinc concentration in the soil. It was also found that functional diversity of microbial communities decreased with increasing zinc concentrations, indicating that increased tolerance is indeed an undesirable phenomenon when environmental quality is considered. The hypothesis that zinc sensitivity of microbial communities is related to background zinc concentration in pore water could not be confirmed. - Zinc sensitivity of microbial communities and functional diversity decrease with increasing zinc concentration in the pore water

  15. Estimating intraspecific genetic diversity from community DNA metabarcoding data

    Directory of Open Access Journals (Sweden)

    Vasco Elbrecht

    2018-04-01

    Full Text Available Background DNA metabarcoding is used to generate species composition data for entire communities. However, sequencing errors in high-throughput sequencing instruments are fairly common, usually requiring reads to be clustered into operational taxonomic units (OTUs, losing information on intraspecific diversity in the process. While Cytochrome c oxidase subunit I (COI haplotype information is limited in resolving intraspecific diversity it is nevertheless often useful e.g. in a phylogeographic context, helping to formulate hypotheses on taxon distribution and dispersal. Methods This study combines sequence denoising strategies, normally applied in microbial research, with additional abundance-based filtering to extract haplotype information from freshwater macroinvertebrate metabarcoding datasets. This novel approach was added to the R package “JAMP” and can be applied to COI amplicon datasets. We tested our haplotyping method by sequencing (i a single-species mock community composed of 31 individuals with 15 different haplotypes spanning three orders of magnitude in biomass and (ii 18 monitoring samples each amplified with four different primer sets and two PCR replicates. Results We detected all 15 haplotypes of the single specimens in the mock community with relaxed filtering and denoising settings. However, up to 480 additional unexpected haplotypes remained in both replicates. Rigorous filtering removes most unexpected haplotypes, but also can discard expected haplotypes mainly from the small specimens. In the monitoring samples, the different primer sets detected 177–200 OTUs, each containing an average of 2.40–3.30 haplotypes per OTU. The derived intraspecific diversity data showed population structures that were consistent between replicates and similar between primer pairs but resolution depended on the primer length. A closer look at abundant taxa in the dataset revealed various population genetic patterns, e.g. the stonefly

  16. [Community structure and diversity of soil arthropods in naturally restored sandy grasslands after grazing].

    Science.gov (United States)

    Liu, Ren-tao; Zhao, Ha-lin; Zhao, Xue-yong

    2010-11-01

    Taking the Naiman Desertification Research Station under Chinese Academy of Sciences as a base, an investigation was conducted on the community structure of soil arthropods in the naturally restored sandy grasslands after different intensity grazing disturbance, with the effects of vegetation and soil on this community structure approached. In the non-grazing grassland, soil arthropods were rich in species and more in individuals, and had the highest diversity. In the restored grassland after light grazing, soil arthropods had the lowest evenness and diversity. In the restored grassland after moderate grazing, the individuals of soil arthropods were lesser but the major groups were more, and the evenness and diversity were higher. In the restored grassland after heavy grazing, the individuals of soil arthropods were more but the major groups were lesser, and the diversity was higher. Plant individuals' number, vegetation height and coverage, and soil alkalinity were the main factors affecting the soil arthropod community in naturally restored grasslands after different intensity grazing disturbance. It was implied that after 12-year exclosure of grassland, soil arthropod community could be recovered to some degree, while grazing disturbance had long-term negative effects on the arthropod community.

  17. Phytoplankton Diversity Effects on Community Biomass and Stability along Nutrient Gradients in a Eutrophic Lake

    Directory of Open Access Journals (Sweden)

    Wang Tian

    2017-01-01

    Full Text Available The relationship between biodiversity and ecosystem functioning is a central issue in ecology, but how this relationship is affected by nutrient stress is still unknown. In this study, we analyzed the phytoplankton diversity effects on community biomass and stability along nutrient gradients in an artificial eutrophic lake. Four nutrient gradients, varying from slightly eutrophic to highly eutrophic states, were designed by adjusting the amount of polluted water that flowed into the lake. Mean phytoplankton biomass, species richness, and Shannon diversity index all showed significant differences among the four nutrient gradients. Phytoplankton community biomass was correlated with diversity (both species richness and Shannon diversity index, varying from positive to negative along the nutrient gradients. The influence of phytoplankton species richness on resource use efficiency (RUE also changed from positive to negative along the nutrient gradients. However, the influence of phytoplankton Shannon diversity on RUE was not significant. Both phytoplankton species richness and Shannon diversity had a negative influence on community turnover (measured as community dissimilarity, i.e., a positive diversity–stability relationship. Furthermore, phytoplankton spatial stability decreased along the nutrient gradients in the lake. With increasing nutrient concentrations, the variability (standard deviation of phytoplankton community biomass increased more rapidly than the average total biomass. Results in this study will be helpful in understanding the phytoplankton diversity effects on ecosystem functioning and how these effects are influenced by nutrient conditions in aquatic ecosystems.

  18. Intraspecific leaf trait variability along a boreal-to-tropical community diversity gradient

    Science.gov (United States)

    Bastias, Cristina C.; Fortunel, Claire; Valladares, Fernando; Baraloto, Christopher; Benavides, Raquel; Cornwell, William; Markesteijn, Lars; de Oliveira, Alexandre A.; Sansevero, Jeronimo B. B.; Vaz, Marcel C.; Kraft, Nathan J. B.

    2017-01-01

    Disentangling the mechanisms that shape community assembly across diversity gradients is a central matter in ecology. While many studies have explored community assembly through species average trait values, there is a growing understanding that intraspecific trait variation (ITV) can also play a critical role in species coexistence. Classic biodiversity theory hypothesizes that higher diversity at species-rich sites can arise from narrower niches relative to species-poor sites, which would be reflected in reduced ITV as species richness increases. To explore how ITV in woody plant communities changes with species richness, we compiled leaf trait data (leaf size and specific leaf area) in a total of 521 woody plant species from 21 forest communities that differed dramatically in species richness, ranging from boreal to tropical rainforests. At each forest, we assessed ITV as an estimate of species niche breadth and we quantified the degree of trait overlap among co-occurring species as a measure of species functional similarity. We found ITV was relatively invariant across the species richness gradient. In addition, we found that species functional similarity increased with diversity. Contrary to the expectation from classic biodiversity theory, our results rather suggest that neutral processes or equalizing mechanisms can be acting as potential drivers shaping community assembly in hyperdiverse forests. PMID:28241033

  19. Functionally diverse reef-fish communities ameliorate coral disease.

    Science.gov (United States)

    Raymundo, Laurie J; Halford, Andrew R; Maypa, Aileen P; Kerr, Alexander M

    2009-10-06

    Coral reefs, the most diverse of marine ecosystems, currently experience unprecedented levels of degradation. Diseases are now recognized as a major cause of mortality in reef-forming corals and are complicit in phase shifts of reef ecosystems to algal-dominated states worldwide. Even so, factors contributing to disease occurrence, spread, and impact remain poorly understood. Ecosystem resilience has been linked to the conservation of functional diversity, whereas overfishing reduces functional diversity through cascading, top-down effects. Hence, we tested the hypothesis that reefs with trophically diverse reef fish communities have less coral disease than overfished reefs. We surveyed reefs across the central Philippines, including well-managed marine protected areas (MPAs), and found that disease prevalence was significantly negatively correlated with fish taxonomic diversity. Further, MPAs had significantly higher fish diversity and less disease than unprotected areas. We subsequently investigated potential links between coral disease and the trophic components of fish diversity, finding that only the density of coral-feeding chaetodontid butterflyfishes, seldom targeted by fishers, was positively associated with disease prevalence. These previously uncharacterized results are supported by a second large-scale dataset from the Great Barrier Reef. We hypothesize that members of the charismatic reef-fish family Chaetodontidae are major vectors of coral disease by virtue of their trophic specialization on hard corals and their ecological release in overfished areas, particularly outside MPAs.

  20. Scale-Dependence of Processes Structuring Dung Beetle Metacommunities Using Functional Diversity and Community Deconstruction Approaches

    Science.gov (United States)

    da Silva, Pedro Giovâni; Hernández, Malva Isabel Medina

    2015-01-01

    Community structure is driven by mechanisms linked to environmental, spatial and temporal processes, which have been successfully addressed using metacommunity framework. The relative importance of processes shaping community structure can be identified using several different approaches. Two approaches that are increasingly being used are functional diversity and community deconstruction. Functional diversity is measured using various indices that incorporate distinct community attributes. Community deconstruction is a way to disentangle species responses to ecological processes by grouping species with similar traits. We used these two approaches to determine whether they are improvements over traditional measures (e.g., species composition, abundance, biomass) for identification of the main processes driving dung beetle (Scarabaeinae) community structure in a fragmented mainland-island landscape in southern Brazilian Atlantic Forest. We sampled five sites in each of four large forest areas, two on the mainland and two on the island. Sampling was performed in 2012 and 2013. We collected abundance and biomass data from 100 sampling points distributed over 20 sampling sites. We studied environmental, spatial and temporal effects on dung beetle community across three spatial scales, i.e., between sites, between areas and mainland-island. The γ-diversity based on species abundance was mainly attributed to β-diversity as a consequence of the increase in mean α- and β-diversity between areas. Variation partitioning on abundance, biomass and functional diversity showed scale-dependence of processes structuring dung beetle metacommunities. We identified two major groups of responses among 17 functional groups. In general, environmental filters were important at both local and regional scales. Spatial factors were important at the intermediate scale. Our study supports the notion of scale-dependence of environmental, spatial and temporal processes in the distribution

  1. Exploring user-producer interaction in an online community : The case of Habbo Hotel

    NARCIS (Netherlands)

    Slot, M.

    2009-01-01

    This article attempts to explore the user-producer interaction in the online community of Habbo Hotel. Based on desk research, interviews, an online survey among more than 3000 Habbo Hotel users in The Netherlands and online discussion groups with 45 Habbos, three specific issues that illustrate the

  2. The relationship between species diversity and genetic structure in the rare Picea chihuahuana tree species community, Mexico.

    Science.gov (United States)

    Simental-Rodríguez, Sergio Leonel; Quiñones-Pérez, Carmen Zulema; Moya, Daniel; Hernández-Tecles, Enrique; López-Sánchez, Carlos Antonio; Wehenkel, Christian

    2014-01-01

    Species diversity and genetic diversity, the most basic elements of biodiversity, have long been treated as separate topics, although populations evolve within a community context. Recent studies on community genetics and ecology have suggested that genetic diversity is not completely independent of species diversity. The Mexican Picea chihuahuana Martínez is an endemic species listed as "Endangered" on the Red List. Forty populations of Chihuahua spruce have been identified. This species is often associated with tree species of eight genera in gallery forests. This rare Picea chihuahuana tree community covers an area no more than 300 ha and has been subject of several studies involving different topics such as ecology, genetic structure and climate change. The overall aim of these studies was to obtain a dataset for developing management tools to help decision makers implement preservation and conservation strategies. However, this unique forest tree community may also represent an excellent subject for helping us to understand the interplay between ecological and evolutionary processes in determining community structure and dynamics. The AFLP technique and species composition data were used together to test the hypothesis that species diversity is related to the adaptive genetic structure of some dominant tree species (Picea chihuahuana, Pinus strobiformis, Pseudotsuga menziesii and Populus tremuloides) of the Picea chihuahuana tree community at fourteen locations. The Hill numbers were used as a diversity measure. The results revealed a significant correlation between tree species diversity and genetic structure in Populus tremuloides. Because the relationship between the two levels of diversity was found to be positive for the putative adaptive AFLP detected, genetic and species structures of the tree community were possibly simultaneously adapted to a combination of ecological or environmental factors. The present findings indicate that interactions between

  3. Primates as Predictors of Mammal Community Diversity in the Forest Ecosystems of Madagascar

    Science.gov (United States)

    Muldoon, Kathleen M.; Goodman, Steven M.

    2015-01-01

    The geographic distribution of species is the typical metric for identifying priority areas for conservation. Since most biodiversity remains poorly studied, a subset of charismatic species, such as primates, often stand as surrogates for total biodiversity. A central question is therefore, how effectively do primates predict the pooled species richness of other mammalian taxa? We used lemurs as indicator species to predict total non-primate mammal community richness in the forest ecosystems of Madagascar. We combine environmental and species occurrence data to ascertain the extent to which primate diversity can predict (1) non-primate mammal α-diversity (species richness), (2) non-primate complementarity, and (3) non-primate β-diversity (species turnover). Our results indicate that primates are effective predictors of non-primate mammal community diversity in the forest ecosystems of Madagascar after controlling for habitat. When individual orders of mammals are considered, lemurs effectively predict the species richness of carnivorans and rodents (but not afrosoricids), complementarity of rodents (but not carnivorans or afrosoricids), and all individual components of β-diversity. We conclude that lemurs effectively predict total non-primate community richness. However, surrogate species alone cannot achieve complete representation of biodiversity. PMID:26334525

  4. Diversity reduces invasibility in experimental plant communities: the role of plant species

    NARCIS (Netherlands)

    Van Ruijven, J.; De Deyn, G.B.; Berendse, F.

    2003-01-01

    Several studies have presented experimental evidence that diversity reduces invasibility in grassland communities. The interpretation of these results has been disputed recently and it was proposed that sampling effects were responsible for the observed decrease of invasibility with diversity. The

  5. SPECIES DIVERSITY AND COMMUNITY STRUCTURE OF SUCKING LICE IN YUNNAN, CHINA

    Institute of Scientific and Technical Information of China (English)

    Xian-guoGuo; Ti-junQian; Li-junGuo; JingWang; Wen-geDong; LiZhang; Zhi-minMa; andWeiLi

    2004-01-01

    On the basis of investigating 9 counties (towns) in Yunnan Province of China, the species diversity and community structure of sucking lice on the body surface of small mammal hosts are studied in the paper. Species richness (S) is used to stand for the species diversity. The calculation of community diversity index and evenness are based on Shannon-Wiener's method. 2745 small mammals captured from the investigated sites belong to 10 families, 25 genera and 41 species in 5 orders (Rodentia, Insectivora, Scandentia, Logomorpha and Carnivora) while 18165 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 4 families, 6 genera and 22 species. The species of sucking lice are much less than the species of their hosts. Most species of small mammals have their fixed sucking lice on their body surface. One species of small mammals usually have few species of sucking lice (1 to 4 species). The close species of the hosts in the taxonomy are found to have the same or similar dominant species of sucking lice on their body surface. The results reveal that the species diversity of sucking lice on small mammals is very low with a very simple community structure. The results also imply there may be a close co-evolution relationship between the lice and the hosts.

  6. Factors explaining user loyalty in a social media-based brand community

    Directory of Open Access Journals (Sweden)

    Louis M. Potgieter

    2017-02-01

    Full Text Available Background: Marketers are interested in taking advantage of the capabilities of social media-based brand communities to develop long-term relationships with their customers. This research investigated the usage of a South African Facebook page to understand user attitudes and attendant pressures on users related to social norms and user loyalty. Objectives: The research investigated the extent to which perceived value, service quality and social factors influenced the customer’s intention to continue using a global motor vehicle firm’s social media-based online brand community (OBC. Method: We used an online voluntary survey to collect data from social media-based brand community members. In total, 303 responses were collected over a period of 4 weeks from a population of 3100 members. We analysed the relationship between trust, perceived responsiveness, perceived usefulness, perceived ease of use, social norms and the members’ intention to continue using the firm’s OBC. 293 usable observations were subjected to descriptive, correlation and regression analysis. Results: The age of the respondents varied from 18 to 58 years with a mean age of 32 years. Of these, 60% were men and 40% women. About 86.7% of the respondents reported having at least some form of tertiary education. The results of the multiple regression analysis indicate that service quality factors such as trust (25.5% and social influence factors such as social norms (12.5% explain a greater part of the variance in OBC continuance intention compared with utility factors such as perceived usefulness (18.2%. The effects for responsiveness and ease of use were not statistically significant. Conclusion: Social media-based brand communities are playing an important role in enhancing the overall trust relationship, value offering, sociality, knowledge and information sharing between customers and firms. Practitioners should note that the loyalty of customers using a firm

  7. mcaGUI: microbial community analysis R-Graphical User Interface (GUI).

    Science.gov (United States)

    Copeland, Wade K; Krishnan, Vandhana; Beck, Daniel; Settles, Matt; Foster, James A; Cho, Kyu-Chul; Day, Mitch; Hickey, Roxana; Schütte, Ursel M E; Zhou, Xia; Williams, Christopher J; Forney, Larry J; Abdo, Zaid

    2012-08-15

    Microbial communities have an important role in natural ecosystems and have an impact on animal and human health. Intuitive graphic and analytical tools that can facilitate the study of these communities are in short supply. This article introduces Microbial Community Analysis GUI, a graphical user interface (GUI) for the R-programming language (R Development Core Team, 2010). With this application, researchers can input aligned and clustered sequence data to create custom abundance tables and perform analyses specific to their needs. This GUI provides a flexible modular platform, expandable to include other statistical tools for microbial community analysis in the future. The mcaGUI package and source are freely available as part of Bionconductor at http://www.bioconductor.org/packages/release/bioc/html/mcaGUI.html

  8. Diversity, Communication, and Leadership in the Community College Faculty Search Process

    Science.gov (United States)

    Fujii, Stephanie J.

    2014-01-01

    This qualitative study investigated ethnic/racial diversity in the community college faculty search process. The researcher interviewed 12 participants--administrators and faculty members at three community colleges in a large district in the southwestern United States--who served on faculty search committees from 2006-2009. Analysis of the…

  9. Analysis of the functional diversity of the microbial communities in a ...

    African Journals Online (AJOL)

    The Biolog method was thus evaluated in a paper-mill water system. The influence of the production of various paper grades, biocide combinations and monthly maintenance shut-downs on the functional diversity of the microbial communities were determined using the Biolog technique. The communities in the planktonic ...

  10. Understanding persistence in the use of online fitness communities : comparing novice and experienced users

    NARCIS (Netherlands)

    Stragier, Jeroen; Vanden Abeele, Mariek; Mechant, Peter; De Marez, Lieven

    2016-01-01

    Mobile and wearable technologies facilitate physiological data collection for health and wellness purposes. Users typically access these data via Online Fitness Community (OFC) platforms (e.g., Fitbit, Strava, RunKeeper). These platforms present users with functionalities centered on

  11. Vascular plant diversity and community Structure of nandi forests ...

    African Journals Online (AJOL)

    Abundance data of species was used for species diversity, similarity, species richness estimation and plant community analysis. PC-ORD, CANOCO and EstimateS were used to analyze the data. A total of 321 species ... Keywords: floristic composition, ordination, rarefaction, species accumulation, species richness.

  12. Bacterial Communities in Malagasy Soils with Differing Levels of Disturbance Affecting Botanical Diversity

    Science.gov (United States)

    Blasiak, Leah C.; Schmidt, Alex W.; Andriamiarinoro, Honoré; Mulaw, Temesgen; Rasolomampianina, Rado; Applequist, Wendy L.; Birkinshaw, Chris; Rejo-Fienena, Félicitée; Lowry, Porter P.; Schmidt, Thomas M.; Hill, Russell T.

    2014-01-01

    Madagascar is well-known for the exceptional biodiversity of its macro-flora and fauna, but the biodiversity of Malagasy microbial communities remains relatively unexplored. Understanding patterns of bacterial diversity in soil and their correlations with above-ground botanical diversity could influence conservation planning as well as sampling strategies to maximize access to bacterially derived natural products. We present the first detailed description of Malagasy soil bacterial communities from a targeted 16S rRNA gene survey of greater than 290,000 sequences generated using 454 pyrosequencing. Two sampling plots in each of three forest conservation areas were established to represent different levels of disturbance resulting from human impact through agriculture and selective exploitation of trees, as well as from natural impacts of cyclones. In parallel, we performed an in-depth characterization of the total vascular plant morphospecies richness within each plot. The plots representing different levels of disturbance within each forest did not differ significantly in bacterial diversity or richness. Changes in bacterial community composition were largest between forests rather than between different levels of impact within a forest. The largest difference in bacterial community composition with disturbance was observed at the Vohibe forest conservation area, and this difference was correlated with changes in both vascular plant richness and soil pH. These results provide the first survey of Malagasy soil bacterial diversity and establish a baseline of botanical diversity within important conservation areas. PMID:24465484

  13. Rationality of Antimicrobial Prescriptions in Community Pharmacy Users.

    Directory of Open Access Journals (Sweden)

    Sara I V C Lima

    Full Text Available Although there is a conflict between the treatment benefits for a single individual and society, restrictions on antibiotic use are needed to reduce the prevalence of resistance to these drugs, which is the main result of irrational use. Brazil, cataloged as a pharmemerging market, has implemented restrictive measures for the consumption of antibiotics. The objective of this study was to investigate the quality of antimicrobial prescriptions and user knowledge of their treatment with these drugs.A two-stage cross-sectional, combined and stratified survey of pharmacy users holding an antimicrobial prescription was conducted in the community between May and November 2014. A pharmacist analyzed each prescription for legibility and completeness, and applied a structured questionnaire to the users or their caregivers on their knowledge regarding treatment and user sociodemographic data. An estimated 29.3% of prescriptions had one or more illegible items, 91.3% had one or more missing items, and 29.0% had both illegible and missing items. Dosing schedule and patient identification were the most commonly unreadable items in prescriptions, 18.81% and 12.14%, respectively. The lack of complete patient identification occurred in 90.53% of the prescriptions. It is estimated that 40.3% of users have used antimicrobials without prescription and that 46.49% did not receive any guidance on the administration of the drug.Despite the measures taken by health authorities to restrict the misuse of antimicrobials, it was observed that prescribers still do not follow the criteria of current legislation, particularly relating to items needed for completion of the prescription. Moreover, users receive little information about their antimicrobial treatment.

  14. Cultural diversity in community sport: an ethnographic inquiry of Somali Australians' experiences

    NARCIS (Netherlands)

    Spaaij, R.

    2013-01-01

    Sport organisations aim to grow the participation of culturally and linguistically diverse communities, including newly arrived people from refugee backgrounds. Drawing on multi-sited ethnographic research conducted by the author at community sport organisations in the multicultural city of

  15. Interpreting ecological diversity indices applied to terminal restriction fragment length polymorphism data: insights from simulated microbial communities.

    Science.gov (United States)

    Blackwood, Christopher B; Hudleston, Deborah; Zak, Donald R; Buyer, Jeffrey S

    2007-08-01

    Ecological diversity indices are frequently applied to molecular profiling methods, such as terminal restriction fragment length polymorphism (T-RFLP), in order to compare diversity among microbial communities. We performed simulations to determine whether diversity indices calculated from T-RFLP profiles could reflect the true diversity of the underlying communities despite potential analytical artifacts. These include multiple taxa generating the same terminal restriction fragment (TRF) and rare TRFs being excluded by a relative abundance (fluorescence) threshold. True community diversity was simulated using the lognormal species abundance distribution. Simulated T-RFLP profiles were generated by assigning each species a TRF size based on an empirical or modeled TRF size distribution. With a typical threshold (1%), the only consistently useful relationship was between Smith and Wilson evenness applied to T-RFLP data (TRF-E(var)) and true Shannon diversity (H'), with correlations between 0.71 and 0.81. TRF-H' and true H' were well correlated in the simulations using the lowest number of species, but this correlation declined substantially in simulations using greater numbers of species, to the point where TRF-H' cannot be considered a useful statistic. The relationships between TRF diversity indices and true indices were sensitive to the relative abundance threshold, with greatly improved correlations observed using a 0.1% threshold, which was investigated for comparative purposes but is not possible to consistently achieve with current technology. In general, the use of diversity indices on T-RFLP data provides inaccurate estimates of true diversity in microbial communities (with the possible exception of TRF-E(var)). We suggest that, where significant differences in T-RFLP diversity indices were found in previous work, these should be reinterpreted as a reflection of differences in community composition rather than a true difference in community diversity.

  16. An Algorithmic Diversity Diet?

    DEFF Research Database (Denmark)

    Sørensen, Jannick Kirk; Schmidt, Jan-Hinrik

    2016-01-01

    With the growing influence of personalized algorithmic recommender systems on the exposure of media content to users, the relevance of discussing the diversity of recommendations increases, particularly as far as public service media (PSM) is concerned. An imagined implementation of a diversity...... diet system however triggers not only the classic discussion of the reach – distinctiveness balance for PSM, but also shows that ‘diversity’ is understood very differently in algorithmic recommender system communities than it is editorially and politically in the context of PSM. The design...... of a diversity diet system generates questions not just about editorial power, personal freedom and techno-paternalism, but also about the embedded politics of recommender systems as well as the human skills affiliated with PSM editorial work and the nature of PSM content....

  17. Evaluating the use of diversity indices to distinguish between microbial communities with different traits.

    Science.gov (United States)

    Feranchuk, Sergey; Belkova, Natalia; Potapova, Ulyana; Kuzmin, Dmitry; Belikov, Sergei

    2018-05-23

    Several measures of biodiversity are commonly used to describe microbial communities, analyzed using 16S gene sequencing. A wide range of available experiments on 16S gene sequencing allows us to present a framework for a comparison of various diversity indices. The criterion for the comparison is the statistical significance of the difference in index values for microbial communities with different traits, within the same experiment. The results of the evaluation indicate that Shannon diversity is the most effective measure among the commonly used diversity indices. The results also indicate that, within the present framework, the Gini coefficient as a diversity index is comparable to Shannon diversity, despite the fact that the Gini coefficient, as a diversity estimator, is far less popular in microbiology than several other measures. Copyright © 2018 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  18. User Generated Diversity - Some reflections on how to improve the quality of amateur productions

    NARCIS (Netherlands)

    Helberger, N.; Leurdijk, A.G.D.; Munck, S.G.E. de

    2010-01-01

    The potential of user created content to make a meaningful contribution to media diversity is subject to debates. Central to these debates is the argument of the quality of amateur productions. This article will take a close look at this argument, and make some suggestions on how to improve the

  19. User generated diversity: some reflections on how to improve the quality of amateur productions

    NARCIS (Netherlands)

    Helberger, N.; Leurdijk, A.; de Munck, S.

    2010-01-01

    The potential of user created content to make a meaningful contribution to media diversity is subject to debates. Central to these debates is the argument of the quality of amateur productions. This article will take a close look at this argument, and make some suggestions on how to improve the

  20. Explaining the diversity of motivations behind community renewable energy

    International Nuclear Information System (INIS)

    Bauwens, Thomas

    2016-01-01

    Community-based renewable energy initiatives may be important actors in the transition toward low-carbon energy systems. In turn, stimulating investments in renewable energy production at the community level requires a better understanding of investors' motives. This paper aims to study the heterogeneity of motivations that drive individuals to participate in community renewable energy projects and the underlying explanatory factors behind this, as well as the implications for their level of engagement in initiatives. Based on quantitative data from an original survey conducted with two renewable energy cooperatives in Flanders, the statistical analysis shows that cooperative members should not be considered as one homogeneous group. Several categories of members with different motives and levels of engagement can be distinguished. This heterogeneity is explained by contrasts in terms of institutional settings, spatial patterns and attitudes to the diffusion of institutional innovations. Regarding policy implications, the findings suggest that this heterogeneity should be taken into account in designing more effective supporting policies to stimulate investments at the community level. The activation of social norms is also shown to be a promising mechanism for triggering investment decisions, although the implications of its interplay with economic incentives should be further explored. - Highlights: •Community-based energy projects are important actors in the low-carbon transition. •The diversity of motivations and level of engagement among members is analysed. •Several segments of members with different characteristics are distinguished. •Institutional, spatial and innovation diffusion dimensions explain this diversity. •This heterogeneity among investors should be taken into account in policy-making.

  1. Diversity and Function of Microbial Community in Chinese Strong-Flavor Baijiu Ecosystem: A Review

    Directory of Open Access Journals (Sweden)

    Wei Zou

    2018-04-01

    Full Text Available Strong flavor baijiu (SFB, also called Luzhou-flavor liquor, is the most popular Chinese baijiu. It is manufactured via solid fermentation, with daqu as the starter. Microbial diversity of the SFB ecosystem and the synergistic effects of the enzymes and compounds produced by them are responsible for the special flavor and mouthfeel of SFB. The present review covers research studies focused on microbial community analysis of the SFB ecosystem, including the culturable microorganisms, their metabolic functions, microbial community diversity and their interactions. The review specifically emphasizes on the most recently conducted culture-independent analysis of SFB microbial community diversity. Furthermore, the possible application of systems biology approaches for elucidating the molecular mechanisms of SFB production were also reviewed and prospected.

  2. Performance of fading multi-user diversity for underlay cognitive networksy

    KAUST Repository

    Khan, Fahd Ahmed

    2013-05-01

    Having multiple secondary users (SUs) can be exploited to achieve multiuser diversity and improve the throughput of the underlay secondary network. In the cognitive setting, satisfying the interference constraint is essential, and thus, a scheduling scheme is considered where some SUs are preselected based on the low interference power. From this subset, the SU that yields the highest throughput is selected for transmission. This scheduling scheme helps to lower the interference power while giving good throughput. For an independent but not identically distributed Nakagami-m fading channel, we obtain exact closed-form expressions of the capacity of this scheduling scheme. Furthermore, the scheduling time of SUs is characterized and closed-form expressions for the mean time after which a SU is selected for transmission are obtained. Numerical simulations are performed to corroborate the derived analytical results. Our results show that at low interference threshold, increasing transmit power of the SUs is not beneficial and results in reduced capacity. Furthermore, the channel idle time (i.e. time that no user is utilizing the channel) reduces with increasing the number of SUs. © 2013 IEEE.

  3. White-tailed deer are a biotic filter during community assembly, reducing species and phylogenetic diversity.

    Science.gov (United States)

    Begley-Miller, Danielle R; Hipp, Andrew L; Brown, Bethany H; Hahn, Marlene; Rooney, Thomas P

    2014-06-09

    Community assembly entails a filtering process, where species found in a local community are those that can pass through environmental (abiotic) and biotic filters and successfully compete. Previous research has demonstrated the ability of white-tailed deer (Odocoileus virginianus) to reduce species diversity and favour browse-tolerant plant communities. In this study, we expand on our previous work by investigating deer as a possible biotic filter altering local plant community assembly. We used replicated 23-year-old deer exclosures to experimentally assess the effects of deer on species diversity (H'), richness (SR), phylogenetic community structure and phylogenetic diversity in paired browsed (control) and unbrowsed (exclosed) plots. Additionally, we developed a deer-browsing susceptibility index (DBSI) to assess the vulnerability of local species to deer. Deer browsing caused a 12 % reduction in H' and 17 % reduction in SR, consistent with previous studies. Furthermore, browsing reduced phylogenetic diversity by 63 %, causing significant phylogenetic clustering. Overall, graminoids were the least vulnerable to deer browsing based on DBSI calculations. These findings demonstrate that deer are a significant driver of plant community assembly due to their role as a selective browser, or more generally, as a biotic filter. This study highlights the importance of knowledge about the plant tree of life in assessing the effects of biotic filters on plant communities. Application of such knowledge has considerable potential to advance our understanding of plant community assembly. Published by Oxford University Press on behalf of the Annals of Botany Company.

  4. Floral diversity increases beneficial arthropod richness and decreases variability in arthropod community composition.

    Science.gov (United States)

    Bennett, Ashley B; Gratton, Claudio

    2013-01-01

    Declines in species diversity resulting from anthropogenic alterations of the environment heighten the need to develop management strategies that conserve species and ecosystem services. This study examined how native plant species and their diversity influence the abundance and richness of beneficial arthropods, a functionally important group that provides ecosystem services such as pollination and natural pest suppression. Beneficial arthropods were sampled in replicated study plots containing native perennials planted in one-, two-, and seven-species mixtures. We found plant diversity had a positive impact on arthropod richness but not on arthropod abundance. An analysis of arthropod community composition revealed that each flower species attracted a different assemblage of beneficial arthropods. In addition, the full seven-species mixture also attracted a distinct arthropod community compared to single-species monocultures. Using a multivariate approach, we determined whether arthropod assemblages in two- and seven-species plots were additive and could be predicted based on assemblages from their component single-species plots. On average, assemblages in diverse plots were nonadditive when compared to assemblages predicted using single-species plots. Arthropod assemblages in two-species plots most closely resembled those of only one of the flower species in the mixture. However, the arthropod assemblages in seven-species plots, although statistically deviating from the expectation of an additive model, more closely resembled predicted communities compared to the assemblages found in two-species plots, suggesting that variability in arthropod community composition decreased as planting diversity increased. Our study demonstrates that careful selection of plants in managed landscapes can augment beneficial arthropod richness and support a more predictable arthropod community, suggesting that planning and design efforts could shape arthropod assemblages in natural

  5. Operating the EOSDIS at the land processes DAAC managing expectations, requirements, and performance across agencies, missions, instruments, systems, and user communities

    Science.gov (United States)

    Kalvelage, T.A.; ,

    2002-01-01

    NASA developed the Earth Observing System (EOS) during the 1990'S. At the Land Processes Distributed Active Archive Center (LP DAAC), located at the USGS EROS Data Center, the EOS Data and Information System (EOSDIS) is required to support heritage missions as well as Landsat 7, Terra, and Aqua. The original system concept of the early 1990'S changed as each community had its say - first the managers, then engineers, scientists, developers, operators, and then finally the general public. The systems at the LP DAAC - particularly the largest single system, the EOSDIS Core System (ECS) - are changing as experience accumulates, technology changes, and each user group gains influence. The LP DAAC has adapted as contingencies were planned for, requirements and therefore plans were modified, and expectations changed faster than requirements could hope to be satisfied. Although not responsible for Quality Assurance of the science data, the LP DAAC works to ensure the data are accessible and useable by influencing systems, capabilities, and data formats where possible, and providing tools and user support as necessary. While supporting multiple missions and instruments, the LP DAAC also works with and learns from multiple management and oversight groups as they review mission requirements, system capabilities, and the overall operation of the LP DAAC. Stakeholders, including the Land Science community, are consulted regularly to ensure that the LP DAAC remains cognizant and responsive to the evolving needs of the user community. Today, the systems do not look or function as originally planned, but they do work, and they allow customers to search and order of an impressive amount of diverse data.

  6. Abundance, diversity and community composition of free-living protozoa on vegetable sprouts.

    Science.gov (United States)

    Chavatte, N; Lambrecht, E; Van Damme, I; Sabbe, K; Houf, K

    2016-05-01

    Interactions with free-living protozoa (FLP) have been implicated in the persistence of pathogenic bacteria on food products. In order to assess the potential involvement of FLP in this contamination, detailed knowledge on their occurrence, abundance and diversity on food products is required. In the present study, enrichment and cultivation methods were used to inventory and quantify FLP on eight types of commercial vegetable sprouts (alfalfa, beetroot, cress, green pea, leek, mung bean, red cabbage and rosabi). In parallel, total aerobic bacteria and Escherichia coli counts were performed. The vegetable sprouts harbored diverse communities of FLP, with Tetrahymena (ciliate), Bodo saltans and cercomonads (flagellates), and Acanthamoeba and Vannella (amoebae) as the dominant taxa. Protozoan community composition and abundance significantly differed between the sprout types. Beetroot harbored the most abundant and diverse FLP communities, with many unique species such as Korotnevella sp., Vannella sp., Chilodonella sp., Podophrya sp. and Sphaerophrya sp. In contrast, mung bean sprouts were species-poor and had low FLP numbers. Sampling month and company had no significant influence, suggesting that seasonal and local factors are of minor importance. Likewise, no significant relationship between protozoan community composition and bacterial load was observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. User acceptance of diesel/PV hybrid system in an island community

    International Nuclear Information System (INIS)

    Phuangpornpitak, N.; Kumar, S.

    2011-01-01

    This paper presents the results of a study conducted at a rural (island) community to understand the role of PV hybrid system installed on an island. Until 2004, most islanders had installed diesel generators in their homes to generate electricity, which was directly supplied to appliances or stored in the batteries for later use. A field survey was carried out to study the user satisfaction of the PV hybrid system in the island community. The attitude of islanders to the PV hybrid system was mostly positive. The islanders can use more electricity, the supply of which can meet the demand. A comparison of pollutions before and after installation of the PV hybrid system was made along with the interviews with the users. The data show that the users are highly satisfied with the PV hybrid system which can reduce environmental impact, especially air and noise pollutions. New opportunities as a result of access to electric service include studying and reading at night that were not possible earlier. All the islanders use the PV hybrid system and more importantly, no one found that the system made their life worse as compared to the earlier state of affairs. (author)

  8. Must Invisible Colleges Be Invisible? An Approach to Examining Large Communities of Network Users.

    Science.gov (United States)

    Ruth, Stephen R.; Gouet, Raul

    1993-01-01

    Discussion of characteristics of users of computer-mediated communication systems and scientific networks focuses on a study of the scientific community in Chile. Topics addressed include users and nonusers; productivity; educational level; academic specialty; age; gender; international connectivity; public policy issues; and future research…

  9. The relative role of dispersal and local interactions for alpine plant community diversity under simulated climate warming

    Energy Technology Data Exchange (ETDEWEB)

    Klanderud, K.; Totland, Oe. [Norwegian Univ. of Life Science, Dept. of Ecology and Natural Resource Management, Aas (Norway)

    2007-08-15

    Most studies on factors determining diversity are conducted in temperate or warm regions, whereas studies in climatically harsh and low productivity areas, such as alpine regions, are rare. We examined the relative roles of seed availability and different biotic and abiotic factors for the diversity of an alpine plant community in southern Norway. Furthermore, because climate warming is predicted to be an important driver of alpine species diversity, we assessed how the relative impacts of dispersal and local interactions on diversity might change under experimental warming (open top chambers, OTCs). Addition of seeds from 27 regional species increased community diversity. The establishment of the species was negatively related both to the diversity of the existing system and the cover of the abundant dwarf shrub Dryas octopetala. These results show that both species dispersal limitation and local biotic interactions are important factors for alpine plant community diversity. Despite relatively harsh environmental conditions and low productivity, competition from the resident vegetation appeared to have a greater role for species establishment and diversity than facilitation and experimental warming. Higher temperature appeared to increase the negative relationship between resident species diversity and species establishment. This may suggest that climate warming can increase the role of interspecific competition for alpine plant community structure, and thus alter the long-term effects of biotic interactions on diversity. (au)

  10. The effects of forest conversion to oil palm on ground-foraging ant communities depend on beta diversity and sampling grain.

    Science.gov (United States)

    Wang, Wendy Y; Foster, William A

    2015-08-01

    Beta diversity - the variation in species composition among spatially discrete communities - and sampling grain - the size of samples being compared - may alter our perspectives of diversity within and between landscapes before and after agricultural conversion. Such assumptions are usually based on point comparisons, which do not accurately capture actual differences in total diversity. Beta diversity is often not rigorously examined. We investigated the beta diversity of ground-foraging ant communities in fragmented oil palm and forest landscapes in Sabah, Malaysia, using diversity metrics transformed from Hill number equivalents to remove dependences on alpha diversity. We compared the beta diversities of oil palm and forest, across three hierarchically nested sampling grains. We found that oil palm and forest communities had a greater percentage of total shared species when larger samples were compared. Across all grains and disregarding relative abundances, there was higher beta diversity of all species among forest communities. However, there were higher beta diversities of common and very abundant (dominant) species in oil palm as compared to forests. Differences in beta diversities between oil palm and forest were greatest at the largest sampling grain. Larger sampling grains in oil palm may generate bigger species pools, increasing the probability of shared species with forest samples. Greater beta diversity of all species in forest may be attributed to rare species. Oil palm communities may be more heterogeneous in common and dominant species because of variable community assembly events. Rare and also common species are better captured at larger grains, boosting differences in beta diversity between larger samples of forest and oil palm communities. Although agricultural landscapes support a lower total diversity than natural forests, diversity especially of abundant species is still important for maintaining ecosystem stability. Diversity in

  11. Diversity Training for Community Aged Care Workers: An Interdisciplinary Meta-Narrative Review

    Science.gov (United States)

    Meyer, Claudia; Ogrin, Rajna; Al-Zubaidi, Hamzah; Appannah, Arti; McMillan, Sally; Barrett, Elizabeth; Browning, Colette

    2017-01-01

    Population ageing signals the need for a responsive community aged care workforce respectful of older people's diverse healthcare needs. Person-centered care premises individual needs and preferences to enhance participation in health care. Training for diversity does not yet exist for this workforce, but is necessary to ensure appropriate care…

  12. Effects of local tree diversity on herbivore communities diminish with increasing forest fragmentation on the landscape scale.

    Directory of Open Access Journals (Sweden)

    Franziska Peter

    Full Text Available Forest fragmentation and plant diversity have been shown to play a crucial role for herbivorous insects (herbivores, hereafter. In turn, herbivory-induced leaf area loss is known to have direct implications for plant growth and reproduction as well as long-term consequences for ecosystem functioning and forest regeneration. So far, previous studies determined diverging responses of herbivores to forest fragmentation and plant diversity. Those inconsistent results may be owed to complex interactive effects of both co-occurring environmental factors albeit they act on different spatial scales. In this study, we investigated whether forest fragmentation on the landscape scale and tree diversity on the local habitat scale show interactive effects on the herbivore community and leaf area loss in subtropical forests in South Africa. We applied standardized beating samples and a community-based approach to estimate changes in herbivore community composition, herbivore abundance, and the effective number of herbivore species on the tree species-level. We further monitored leaf area loss to link changes in the herbivore community to the associated process of herbivory. Forest fragmentation and tree diversity interactively affected the herbivore community composition, mainly by a species turnover within the family of Curculionidae. Furthermore, herbivore abundance increased and the number of herbivore species decreased with increasing tree diversity in slightly fragmented forests whereas the effects diminished with increasing forest fragmentation. Surprisingly, leaf area loss was neither affected by forest fragmentation or tree diversity, nor by changes in the herbivore community. Our study highlights the need to consider interactive effects of environmental changes across spatial scales in order to draw reliable conclusions for community and interaction patterns. Moreover, forest fragmentation seems to alter the effect of tree diversity on the herbivore

  13. The role of schools in promoting inclusive communities in contexts of diversity.

    Science.gov (United States)

    Andreouli, Eleni; Howarth, Caroline; Sonn, Christopher

    2014-01-01

    Against the background of evidence for links between ill-health and prejudice, in this article we discuss how to promote inclusive communities in contexts of diversity. A brief critical overview of dominant psychological approaches to prejudice reduction reveals the apolitical nature of these approaches, and thus, we argue for a more contextual and political model on how to promote inclusive communities. Drawing on examples of different school practices on cultural diversity from across England, we argue that we need to develop a perspective that connects local contexts of everyday practice, resistance and agency to the institutional and structural realities of prejudice.

  14. Is there a positive relationship between naturalness and genetic diversity in forest tree communities?

    OpenAIRE

    Wehenkel, C.; Corral-Rivas, J. J.; Castellanos-Bocaz, H. A.; Pinedo-Alvarez, A.

    2009-01-01

    The concepts of genetic diversity and naturalness are well known as measures of conservation values and as descriptors of state or condition. A lack of research evaluating the relationship between genetic diversity and naturalness in biological communities, along with the possible implications in terms of evolutionary aspects and conservation management, make this subject particularly important as regards forest tree communities.We therefore examined the following hypothesis: the genetic dive...

  15. Training a medical workforce to meet the needs of diverse minority communities.

    Science.gov (United States)

    Sopoaga, Faafetai; Zaharic, Tony; Kokaua, Jesse; Covello, Sahra

    2017-01-21

    The growing demand for a competent health workforce to meet the needs of increasingly diverse societies has been widely acknowledged. One medical school in New Zealand explored the integration of the commonly used patient-centred model approach, with an intersectional framework in the development of a cultural competency training programme. In the Pacific Immersion Programme, medical students in their fourth year of training are given the opportunity to learn about different factors that influence the health and health care of a minority community through immersion in that community. The programme objectives include enabling students to learn through experience living within the local community context, and supporting them to re-evaluate their own personal beliefs, assumptions and/or prior prejudices. This study evaluates the usefulness of this programme in the training of medical students to work in diverse communities. Two analytical approaches were used for evaluation. Deductive and inductive analyses were conducted on 235 reflective essays completed by three cohorts of students from 2011 to 2013 to ascertain the value of the programme for student learning. In addition, one cohort was invited to complete a pre and post-programme questionnaire. Overall, the students found the programme to be a valued learning environment. They found living within a Pacific family environment to be an eye opening experience. It increased students comfort level in cross cultural engagement and emphasised the importance of patient's perspectives in health care provision. Students' self-reported knowledge about Pacific cultural values, protocols, traditional beliefs and the main health challenges increased significantly after the programme. They appreciated learning directly from community members, and through observations about how culture, beliefs and the socio-economic environment influence peoples' health and wellbeing. Medical schools are required to train a competent health

  16. Classification of High-Mountain Vegetation Communities within a Diverse Giant Mountains Ecosystem Using Airborne APEX Hyperspectral Imagery

    Directory of Open Access Journals (Sweden)

    Adriana Marcinkowska-Ochtyra

    2018-04-01

    Full Text Available Mapping plant communities is a difficult and time consuming endeavor. Methods relying on field surveys deliver high quality data but are usually limited to relatively small areas. In this paper we apply airborne hyperspectral data to vegetation mapping in remote and hard to reach areas. We classified 22 vegetation communities in the Giant Mountains on 3.12-m Airborne Prism Experiment (APEX hyperspectral images, registered in 288 spectral bands (10 September 2012. As the classification algorithm, Support Vector Machines (SVM was used. APEX data were corrected geometrically and atmospherically, and three dimensionality reduction methods were performed to select the best dataset. As reference we used a non-forest vegetation map containing vegetation communities of Polish Karkonosze National Park from 2002, orthophotomap and field surveys data from 2013 to 2014. We obtained the post-classification maps of 22 vegetation communities, lakes and areas without any vegetation. Iterative accuracy assessment repeated 100 times was used to obtain the most objective results for individual communities. The median value of overall accuracy (OA was 84%. Fourteen out of twenty-four classes were classified of more than 80% of producer accuracy (PA and sixteen out of twenty-four of user accuracy (UA. APEX data and SVM with the use of iterative accuracy assessment are useful for the mountain communities classification. This can support both Polish and Czech national parks management by giving the information about diversity of communities in the whole transboundary area, helping with identification especially in changing environment caused by humans.

  17. Modeling microbial community structure and functional diversity across time and space.

    Science.gov (United States)

    Larsen, Peter E; Gibbons, Sean M; Gilbert, Jack A

    2012-07-01

    Microbial communities exhibit exquisitely complex structure. Many aspects of this complexity, from the number of species to the total number of interactions, are currently very difficult to examine directly. However, extraordinary efforts are being made to make these systems accessible to scientific investigation. While recent advances in high-throughput sequencing technologies have improved accessibility to the taxonomic and functional diversity of complex communities, monitoring the dynamics of these systems over time and space - using appropriate experimental design - is still expensive. Fortunately, modeling can be used as a lens to focus low-resolution observations of community dynamics to enable mathematical abstractions of functional and taxonomic dynamics across space and time. Here, we review the approaches for modeling bacterial diversity at both the very large and the very small scales at which microbial systems interact with their environments. We show that modeling can help to connect biogeochemical processes to specific microbial metabolic pathways. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  18. Diversity of herbaceous plants and bacterial communities regulates soil resistome across forest biomes.

    Science.gov (United States)

    Hu, Hang-Wei; Wang, Jun-Tao; Singh, Brajesh K; Liu, Yu-Rong; Chen, Yong-Liang; Zhang, Yu-Jing; He, Ji-Zheng

    2018-04-24

    Antibiotic resistance is ancient and prevalent in natural ecosystems and evolved long before the utilization of synthetic antibiotics started, but factors influencing the large-scale distribution patterns of natural antibiotic resistance genes (ARGs) remain largely unknown. Here, a large-scale investigation over 4000 km was performed to profile soil ARGs, plant communities and bacterial communities from 300 quadrats across five forest biomes with minimal human impact. We detected diverse and abundant ARGs in forests, including over 160 genes conferring resistance to eight major categories of antibiotics. The diversity of ARGs was strongly and positively correlated with the diversity of bacteria, herbaceous plants and mobile genetic elements (MGEs). The ARG composition was strongly correlated with the taxonomic structure of bacteria and herbs. Consistent with this strong correlation, structural equation modelling demonstrated that the positive effects of bacterial and herb communities on ARG patterns were maintained even when simultaneously accounting for multiple drivers (climate, spatial predictors and edaphic factors). These findings suggest a paradigm that the interactions between aboveground and belowground communities shape the large-scale distribution of soil resistomes, providing new knowledge for tackling the emerging environmental antibiotic resistance. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Exploring the role of intermediaries in firm-user community collaborations: resolving or multiplying conflicts?

    DEFF Research Database (Denmark)

    Dragsdahl Lauritzen, Ghita

    2015-01-01

    in which they originate. Nevertheless, despite its popularity there is still a paucity of studies on intermediaries mediating firm-community collaboration. On the basis of an embedded case study, this article suggests that instead of resolving conflicts, intermediaries create a new membership construct......Research on user innovation shows that innovation can be impeded by the conflicting demands that arise in the context of collaborations between firms and their user communities. Studies argue that intermediary organizations can help to resolve these conflicts, by bridging the opposing logics...... from which new tensions arise. I propose that if intermediary organizations foster a clearer view of this membership construct, the result can be an innovative synthesis of opposing logics. Thus, I suggest a novel approach to the debate about user innovation by arguing that mediating firm...

  20. Forest management type influences diversity and community composition of soil fungi across temperate forest ecosystems

    Directory of Open Access Journals (Sweden)

    Kezia eGoldmann

    2015-11-01

    Full Text Available Fungal communities have been shown to be highly sensitive towards shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L., with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L. or spruce (Picea abies Karst. which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure.We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal OTU richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera.This study extends our knowledge

  1. Forest Management Type Influences Diversity and Community Composition of Soil Fungi across Temperate Forest Ecosystems.

    Science.gov (United States)

    Goldmann, Kezia; Schöning, Ingo; Buscot, François; Wubet, Tesfaye

    2015-01-01

    Fungal communities have been shown to be highly sensitive toward shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L.), with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L.) or spruce (Picea abies Karst.) which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure. We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal operational taxonomic units richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM) and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera. This study extends our

  2. Users' Continuance Intention of Virtual Learning Community Services: The Moderating Role of Usage Experience

    Science.gov (United States)

    Zhang, Min; Liu, Yupei; Yan, Weiwei; Zhang, Yan

    2017-01-01

    Users' continuance intention plays a significant role in the process of information system (IS) service, especially virtual learning community (VLC) services. Following the IS success model and IS post-acceptance model, this study explores the determinants of users' intention to continue using VLCs' service from the perspective of quality,…

  3. Service users' expectations of treatment and support at the Community Mental Health Centre in their recovery.

    Science.gov (United States)

    Biringer, Eva; Davidson, Larry; Sundfør, Bengt; Ruud, Torleif; Borg, Marit

    2017-09-01

    Focus on service users' needs, coping and empowerment, user involvement, and comprehensiveness are supposed to be key elements of the Community Mental Health Centres in Norway. Taking a user-oriented approach means acknowledging the individual's own expectations, aims and hopes. However, studies that have investigated service users' expectations of treatment and support at Community Mental Health Centres are hard to find. The aim of the study was therefore to explore service users' expectations at the start of treatment at a Community Mental Health Centre. Within a collaborative framework, taking a hermeneutic-phenomenological approach, ten service users participated in in-depth interviews about their expectations, hopes and aims for treatment and recovery. The participants sought help due to various mental health issues that had interfered with their lives and created disability and suffering. A data-driven stepwise approach in line with thematic analysis was used. The study was approved by the Norwegian Social Science Data Services. The following four main themes representing participants' expectations at the start of treatment were elicited: hope for recovery, developing understanding, finding tools for coping and receiving counselling and practical assistance. Participants' expectations about treatment were tightly interwoven with their personal aims and hopes for their future life, and expectations were often related to practical and financial problems, the solution of which being deemed necessary to gain a safe basis for recovery in the long run. The transferability of the results may be limited by the small number of participants. The study emphasises how important it is that service users' personal aims and expectations guide the collaborative treatment process. In addition to providing treatment aimed at improving symptoms, Community Mental Health Centres should take a more comprehensive approach than today by providing more support with family issues

  4. SPECIES DIVERSITY AND COMMUNITY STRUCTURE OF FRUIT-FEEDING BUTTERFLIES (LEPIDOPTERA: NYMPHALIDAE) IN AN EASTERN AMAZONIAN FOREST

    OpenAIRE

    MARTINS, LUCAS PEREIRA; ARAUJO JUNIOR, ELIAS DA COSTA; MARTINS, ANANDA REGINA PEREIRA; DUARTE, MARCELO; AZEVEDO, GISELE GARCIA

    2017-01-01

    ABSTRACT Deforestation has negative impacts on diversity and community patterns of several taxa. In the eastern Amazon, where much deforestation is predicted for the coming years, forests patches may be essential to maintain the local biodiversity. Despite increasing concerns about the conservation of threatened areas, few studies have been performed to analyze the communities of diversified groups, such as insects, in the eastern Amazon. Here, we investigated species diversity and community ...

  5. Trait-mediated assembly processes predict successional changes in community diversity of tropical forests.

    Science.gov (United States)

    Lasky, Jesse R; Uriarte, María; Boukili, Vanessa K; Chazdon, Robin L

    2014-04-15

    Interspecific differences in relative fitness can cause local dominance by a single species. However, stabilizing interspecific niche differences can promote local diversity. Understanding these mechanisms requires that we simultaneously quantify their effects on demography and link these effects to community dynamics. Successional forests are ideal systems for testing assembly theory because they exhibit rapid community assembly. Here, we leverage functional trait and long-term demographic data to build spatially explicit models of successional community dynamics of lowland rainforests in Costa Rica. First, we ask what the effects and relative importance of four trait-mediated community assembly processes are on tree survival, a major component of fitness. We model trait correlations with relative fitness differences that are both density-independent and -dependent in addition to trait correlations with stabilizing niche differences. Second, we ask how the relative importance of these trait-mediated processes relates to successional changes in functional diversity. Tree dynamics were more strongly influenced by trait-related interspecific variation in average survival than trait-related responses to neighbors, with wood specific gravity (WSG) positively correlated with greater survival. Our findings also suggest that competition was mediated by stabilizing niche differences associated with specific leaf area (SLA) and leaf dry matter content (LDMC). These drivers of individual-level survival were reflected in successional shifts to higher SLA and LDMC diversity but lower WSG diversity. Our study makes significant advances to identifying the links between individual tree performance, species functional traits, and mechanisms of tropical forest succession.

  6. Exposing the Strategies that Can Reduce the Obstacles: Improving the Science User Experience

    Science.gov (United States)

    Lindsay, Francis E.; Brennan, Jennifer; Behnke, Jeanne; Lynnes, Chris

    2017-01-01

    It is now well established that pursuing generic solutions to what seem are common problems in Earth science data access and use can often lead to disappointing results for both system developers and the intended users. This presentation focuses on real-world experience of managing a large and complex data system, NASAs Earth Science Data and Information Science System (EOSDIS), whose mission is to serve both broad user communities and those in smaller niche applications of Earth science data and services. In the talk, we focus on our experiences with known data user obstacles characterizing EOSDIS approaches, including various technological techniques, for engaging and bolstering, where possible, user experiences with EOSDIS. For improving how existing and prospective users discover and access NASA data from EOSDIS we introduce our cross-archive tool: Earthdata Search. This new search and order tool further empowers users to quickly access data sets using clever and intuitive features. The Worldview data visualization tool is also discussed highlighting how many users are now performing extensive data exploration without necessarily downloading data. Also, we explore our EOSDIS data discovery and access webinars, data recipes and short tutorials, targeted technical and data publications, user profiles and social media as additional tools and methods used for improving our outreach and communications to a diverse user community. These efforts have paid substantial dividends for our user communities by allowing us to target discipline specific community needs. The desired take-away from this presentation will be an improved understanding of how EOSDIS has approached, and in several instances achieved, removing or lowering the barriers to data access and use. As we look ahead to more complex Earth science missions, EOSDIS will continue to focus on our user communities, both broad and specialized, so that our overall data system can continue to serve the needs of

  7. Exposing the Strategies that can Reduce the Obstacles: Improving the Science User Experience

    Science.gov (United States)

    Lindsay, F. E.; Brennan, J.; Behnke, J.; Lynnes, C.

    2017-12-01

    It is now well established that pursuing generic solutions to what seem are common problems in Earth science data access and use can often lead to disappointing results for both system developers and the intended users. This presentation focuses on real-world experience of managing a large and complex data system, NASA's Earth Science Data and Information Science System (EOSDIS), whose mission is to serve both broad user communities and those in smaller niche applications of Earth science data and services. In the talk, we focus on our experiences with known data user obstacles characterizing EOSDIS approaches, including various technological techniques, for engaging and bolstering, where possible, user experiences with EOSDIS. For improving how existing and prospective users discover and access NASA data from EOSDIS we introduce our cross-archive tool: Earthdata Search. This new search and order tool further empowers users to quickly access data sets using clever and intuitive features. The Worldview data visualization tool is also discussed highlighting how many users are now performing extensive data exploration without necessarily downloading data. Also, we explore our EOSDIS data discovery and access webinars, data recipes and short tutorials, targeted technical and data publications, user profiles and and social media as additional tools and methods used for improving our outreach and communications to a diverse user community. These efforts have paid substantial dividends for our user communities by allowing us to target discipline specific community needs. The desired take-away from this presentation will be an improved understanding of how EOSDIS has approached, and in several instances achieved, removing or lowering the barriers to data access and use. As we look ahead to more complex Earth science missions, EOSDIS will continue to focus on our user communities, both broad and specialized, so that our overall data system can continue to serve the needs of

  8. Community Audit of Social, Civil, and Activity Domains in Diverse Environments (CASCADDE).

    Science.gov (United States)

    Knapp, Emily A; Nau, Claudia; Brandau, Sy; DeWalle, Joseph; Hirsch, Annemarie G; Bailey-Davis, Lisa; Schwartz, Brian S; Glass, Thomas A

    2017-04-01

    There are currently no direct observation environmental audit tools that measure diverse aspects of the obesity-related environment efficiently and reliably in a variety of geographic settings. The goal was to develop a new instrument to reliably characterize the overall properties and features of rural, suburban, and urban settings along multiple dimensions. The Community Audit of Social, Civil, and Activity Domains in Diverse Environments (CASCADDE) is an iPad-based instrument that incorporates GPS coordinates and photography and comprises 214 items yielding seven summary indices. A comprehensive spatial sampling strategy, training manual, and supporting data analysis code were also developed. Random geospatial sampling using GIS was used to capture features of the community as a whole. A single auditor collected 510 observation points in 30 communities (2013-2015). This analysis was done in 2015-2016. Correlation coefficients were used to compare items and indices to each other and to standard measures. Multilevel unconditional means models were used to calculate intraclass correlation coefficients to determine if there was significant variation between communities. Results suggest that CASCADDE measures aspects of communities not previously captured by secondary data sources. Additionally, seven summary indices capture meaningful differences between communities based on 15 observations per community. Community audit tools such as CASCADDE complement secondary data sources and have the potential to offer new insights about the mechanisms through which communities affect obesity and other health outcomes. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  9. Data and Science: GES DISC Users' Data Usage and Science Exploration

    Science.gov (United States)

    Shie, C. L.; Greene, M.; Acker, J. G.; Lei, G. D.; Al-Jazrawi, A. F.; Meyer, D. J.

    2017-12-01

    Motivation: Recall the arguably most renowned anecdote in the history of science: the young Isaac Newton was hit on his head by a falling apple (the data!) when he sat in his garden, which inspired Newton's brilliant insight and his eventually understanding and demonstrating of gravitational force (the science!). This well-known "coupling" of "data" and "science" can be considered as the trigger for this study (as well as its title). The NASA Goddard Earth Sciences Data and Information Service Center (GES DISC) has provided massive amounts of Earth science data, information, and services to diverse research communities and the general public for decades. How much those data products from different missions or projects have been used by diverse user communities, as well as how they have been used by our various user categories (such as research scientists, applications scientists, general public, and students) for different science research or/and applications are the primary focus of this study. We have performed an integrated analysis on "data usage" vs. "science research/application" by investigating three different, yet related, groups of records, i.e., user Help Tickets (the questions and feedback from the users), user publications (info acquired especially via users' acknowledgments of using Giovanni, our powerful in-house visualization tool, in their papers), and user metrics (the collected information of data and service usage by the users) in recent years (2013-2017). For example, precipitation, hydrology, and atmospheric chemistry have been found as frequently applied science variables or/and science areas that have been exploited or/and explored by the users based on the user tickets we have analyzed so far. With regard to Giovanni, a significant minority of the users are applications users (air quality, water quality, agriculture, natural disasters, etc.) in contrast to the majority of basic research users. More users employ Giovanni as an adjunct data

  10. [Diversity and classification system of weed community in Harbin City, China].

    Science.gov (United States)

    Chen, Xiao-Shuang; Liang, Hong; Song, Kun; Da, Liang-Jun

    2014-08-01

    To analyze the causes of weed community diversity and their strategies of adaption to the high heterogeneity of urban habitats, weed communities in the central urban area of Harbin, China were studied, and a classification system was established for the weed communities. There were 175 weed species, belonging to 128 genera and 38 families. The heterogeneous urban habitats and species' temporal niche differentiation resulted in the highly diversified weed communities. The high proportions of mono-species dominance and annual species dominance communities were their response to the unstable urban habitats under human disturbances with high intensities and frequencies. A four-level classification system was established in terms of plant species and habitat conditions. Within this system, the identified 1763 weed communities could be categorized into two types of life form, 5 types of dormancy form, 22 community groups, and 119 dominance communities.

  11. HYGROTOPE AND TROPHOTOPE OF THE STEPPE PRIDNIPROVIE BIOGEOCEONOSIS AS DETERMINANTS OF THE EARTHWORMS (LUMBRICIDAE COMMUNITIES β-DIVERSITY

    Directory of Open Access Journals (Sweden)

    A. V. Zhukov

    2016-08-01

    Full Text Available The role of the hygrotope and trophotope of the steppe Pridniprovie biogeoceonosis has been discussed in present article as being determinants of the β-diversity of earthworms (Lumbricidae communities. Material has been colected to the period 1997-2015. 180 sample polygons have been studied which located in various types of biogeoceonosis. Biogeoceonotic characteristic of the sample polygons have been made on the basis of professor A.L. Belgard forest typology of a steppe zone of Ukraine. Earthworm communities of the steppe Pridniprovie have been established to be presented by 16 species. Hygrotopes, trophotopes and bitope ceonosis features have been shown to be able to explain 72.4 % of a communities’ abundance variation and 73.7 of their % α-diversity by means of second order model. Earthworm communities’ abundance reache their maximum values at a combination of conditions of humidity from hygromesophilous to hygrophilous and conditions of edaphotope trophicity from Dc (linden oakwood to Dn (elm-ashen oakwood and alder forests. The maximum diversity of earthworm communities has been stated to be characteristic for a combination of mesohygrophilous conditions and a trophicity mode Dc, that there corresponds to forest type a linden oakwood with aegopodium. The coenomorphic structure of the biogeocoenosis is statistically significant predictors of both abundance and α-diversity of earthworm communities. Earthworm communities of marsh monocoenosis, meadow-steppe amphicoenosis and steppe monocoenosis have been found as being characterised by minimum abundance and diversity. Moderate level abundance and diversity are characteristic for meadow-forest amphicoenosis, forest pseudomonocoenosis with elements of transformation to steppe and forest-steppe amphicoenosis. High levels of these indexes are typical for forest monocoenosis. Given other conditions of humidity and edaphotope trophicity being equal in forest monocoenosis abundance and

  12. Phylogenetic diversity, host-specificity and community profiling of sponge-associated bacteria in the northern Gulf of Mexico.

    Science.gov (United States)

    Erwin, Patrick M; Olson, Julie B; Thacker, Robert W

    2011-01-01

    Marine sponges can associate with abundant and diverse consortia of microbial symbionts. However, associated bacteria remain unexamined for the majority of host sponges and few studies use phylogenetic metrics to quantify symbiont community diversity. DNA fingerprinting techniques, such as terminal restriction fragment length polymorphisms (T-RFLP), might provide rapid profiling of these communities, but have not been explicitly compared to traditional methods. We investigated the bacterial communities associated with the marine sponges Hymeniacidon heliophila and Haliclona tubifera, a sympatric tunicate, Didemnum sp., and ambient seawater from the northern Gulf of Mexico by combining replicated clone libraries with T-RFLP analyses of 16S rRNA gene sequences. Clone libraries revealed that bacterial communities associated with the two sponges exhibited lower species richness and lower species diversity than seawater and tunicate assemblages, with differences in species composition among all four source groups. T-RFLP profiles clustered microbial communities by source; individual T-RFs were matched to the majority (80.6%) of clone library sequences, indicating that T-RFLP analysis can be used to rapidly profile these communities. Phylogenetic metrics of community diversity indicated that the two sponge-associated bacterial communities include dominant and host-specific bacterial lineages that are distinct from bacteria recovered from seawater, tunicates, and unrelated sponge hosts. In addition, a large proportion of the symbionts associated with H. heliophila were shared with distant, conspecific host populations in the southwestern Atlantic (Brazil). The low diversity and species-specific nature of bacterial communities associated with H. heliophila and H. tubifera represent a distinctly different pattern from other, reportedly universal, sponge-associated bacterial communities. Our replicated sampling strategy, which included samples that reflect the ambient

  13. Bacterial diversity and community structure of a sub-surface aquifer exposed to realistic low herbicide concentrations

    DEFF Research Database (Denmark)

    Lipthay, Julia R. de; Johnsen, Kaare; Albrechtsen, H.-J.

    2004-01-01

    contaminants. We examined the effect of in situ exposure to realistic low concentrations of herbicides on the microbial diversity and community structure of sub-surface sediments from a shallow aquifer near Vejen (Denmark). Three different community analyses were performed: colony morphology typing, sole...... community analyses. In contrast, no significant effect was found on the bacterial diversity, except for the culturable fraction where a significantly increased richness and Shannon index was found in the herbicide acclimated sediments. The results of this study show that in situ exposure of sub-surface...... aquifers to realistic low concentrations of herbicides may alter the overall structure of a natural bacterial community, although significant effects on the genetic diversity and carbon substrate usage cannot be detected. The observed impact was probably due to indirect effects. In future investigations...

  14. Short-term parasite-infection alters already the biomass, activity and functional diversity of soil microbial communities

    Science.gov (United States)

    Li, Jun-Min; Jin, Ze-Xin; Hagedorn, Frank; Li, Mai-He

    2014-11-01

    Native parasitic plants may be used to infect and control invasive plants. We established microcosms with invasive Mikania micrantha and native Coix lacryma-jobi growing in mixture on native soils, with M. micrantha being infected by parasitic Cuscuta campestris at four intensity levels for seven weeks to estimate the top-down effects of plant parasitism on the biomass and functional diversity of soil microbial communities. Parasitism significantly decreased root biomass and altered soil microbial communities. Soil microbial biomass decreased, but soil respiration increased at the two higher infection levels, indicating a strong stimulation of soil microbial metabolic activity (+180%). Moreover, a Biolog assay showed that the infection resulted in a significant change in the functional diversity indices of soil microbial communities. Pearson correlation analysis indicated that microbial biomass declined significantly with decreasing root biomass, particularly of the invasive M. micrantha. Also, the functional diversity indices of soil microbial communities were positively correlated with soil microbial biomass. Therefore, the negative effects on the biomass, activity and functional diversity of soil microbial community by the seven week long plant parasitism was very likely caused by decreased root biomass and root exudation of the invasive M. micrantha.

  15. Diversity training for the community aged care workers: A conceptual framework for evaluation.

    Science.gov (United States)

    Appannah, Arti; Meyer, Claudia; Ogrin, Rajna; McMillan, Sally; Barrett, Elizabeth; Browning, Colette

    2017-08-01

    Older Australians are an increasingly diverse population, with variable characteristics such as culture, sexual orientation, socioeconomic status, and physical capabilities potentially influencing their participation in healthcare. In response, community aged care workers may need to increase skills and uptake of knowledge into practice regarding diversity through appropriate training interventions. Diversity training (DT) programs have traditionally existed in the realm of business, with little research attention devoted to scientifically evaluating the outcomes of training directed at community aged care workers. A DT workshop has been developed for community aged care workers, and this paper focuses on the construction of a formative evaluative framework for the workshop. Key evaluation concepts and measures relating to DT have been identified in the literature and integrated into the framework, focusing on five categories: Training needs analysis; Reactions; Learning outcomes, Behavioural outcomes and Results The use of a mixed methods approach in the framework provides an additional strength, by evaluating long-term behavioural change and improvements in service delivery. As little is known about the effectiveness of DT programs for community aged care workers, the proposed framework will provide an empirical and consistent method of evaluation, to assess their impact on enhancing older people's experience of healthcare. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Decoupling phylogenetic and functional diversity to reveal hidden signals in community assembly

    Czech Academy of Sciences Publication Activity Database

    de Bello, Francesco; Šmilauer, P.; Diniz-Filho, J. A. F.; Carmona, C. P.; Lososová, Z.; Herben, Tomáš; Götzenberger, Lars

    2017-01-01

    Roč. 8, č. 10 (2017), s. 1200-1211 ISSN 2041-210X R&D Projects: GA ČR(CZ) GA16-15012S; GA ČR GB14-36079G EU Projects: European Commission(XE) 267243 Institutional support: RVO:67985939 Keywords : community ecology * phylogenetic diversity * functional diversity Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 5.708, year: 2016

  17. A User-Centric Diversity by Design Recommender System for the Movie Application Domain

    DEFF Research Database (Denmark)

    Zanitti, Michele; Kosta, Sokol; Sørensen, Jannick Kirk

    2018-01-01

    Recommender systems (RS) have seen widespread adoption across the Internet. However, by emphasizing personalization through the optimization of accuracy-focused metrics, over-personalization may emerge, with negative effects on the user experience. A countermeasure to the problem is to diversify...... recommendations. In this paper, we present a solution that addresses the problem in the context of a movie application domain. The solution enhances diversity on four related dimensions, namely global coverage, local coverage, novelty, and redundancy. The proposed solution is designed to diversify users profiles......, modeled on categorical preferences, within the same group in the recommendation filtering. We evaluate our approach on the Movielens dataset and show that our algorithm yields better results compared to random selection distant neighbors and performs comparably to one of the current state of the art...

  18. Temporal and Spatial Diversity of Bacterial Communities in Coastal Waters of the South China Sea

    Science.gov (United States)

    Du, Jikun; Xiao, Kai; Li, Li; Ding, Xian; Liu, Helu; Lu, Yongjun; Zhou, Shining

    2013-01-01

    Bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems. Temporal and geographical patterns in ocean bacterial communities have been observed in many studies, but the temporal and spatial patterns in the bacterial communities from the South China Sea remained unexplored. To determine the spatiotemporal patterns, we generated 16S rRNA datasets for 15 samples collected from the five regularly distributed sites of the South China Sea in three seasons (spring, summer, winter). A total of 491 representative sequences were analyzed by MOTHUR, yielding 282 operational taxonomic units (OTUs) grouped at 97% stringency. Significant temporal variations of bacterial diversity were observed. Richness and diversity indices indicated that summer samples were the most diverse. The main bacterial group in spring and summer samples was Alphaproteobacteria, followed by Cyanobacteria and Gammaproteobacteria, whereas Cyanobacteria dominated the winter samples. Spatial patterns in the samples were observed that samples collected from the coastal (D151, D221) waters and offshore (D157, D1512, D224) waters clustered separately, the coastal samples harbored more diverse bacterial communities. However, the temporal pattern of the coastal site D151 was contrary to that of the coastal site D221. The LIBSHUFF statistics revealed noticeable differences among the spring, summer and winter libraries collected at five sites. The UPGMA tree showed there were temporal and spatial heterogeneity of bacterial community composition in coastal waters of the South China Sea. The water salinity (P=0.001) contributed significantly to the bacteria-environment relationship. Our results revealed that bacterial community structures were influenced by environmental factors and community-level changes in 16S-based diversity were better explained by spatial patterns than by temporal patterns. PMID:23785512

  19. Macro and Microelements Drive Diversity and Composition of Prokaryotic and Fungal Communities in Hypersaline Sediments and Saline-Alkaline Soils.

    Science.gov (United States)

    Liu, Kaihui; Ding, Xiaowei; Tang, Xiaofei; Wang, Jianjun; Li, Wenjun; Yan, Qingyun; Liu, Zhenghua

    2018-01-01

    Understanding the effects of environmental factors on microbial communities is critical for microbial ecology, but it remains challenging. In this study, we examined the diversity (alpha diversity) and community compositions (beta diversity) of prokaryotes and fungi in hypersaline sediments and salinized soils from northern China. Environmental variables were highly correlated, but they differed significantly between the sediments and saline soils. The compositions of prokaryotic and fungal communities in the hypersaline sediments were different from those in adjacent saline-alkaline soils, indicating a habitat-specific microbial distribution pattern. The macroelements (S, P, K, Mg, and Fe) and Ca were, respectively, correlated closely with the alpha diversity of prokaryotes and fungi, while the macronutrients (e.g., Na, S, P, and Ca) were correlated with the prokaryotic and fungal beta-diversity ( P ≤ 0.05). And, the nine microelements (e.g., Al, Ba, Co, Hg, and Mn) and micronutrients (Ba, Cd, and Sr) individually shaped the alpha diversity of prokaryotes and fungi, while the six microelements (e.g., As, Ba, Cr, and Ge) and only the trace elements (Cr and Cu), respectively, influenced the beta diversity of prokaryotes and fungi ( P analysis (VPA) showed that environmental variables jointly explained 55.49% and 32.27% of the total variation for the prokaryotic and fungal communities, respectively. Together, our findings demonstrate that the diversity and community composition of the prokaryotes and fungi were driven by different macro and microelements in saline habitats, and that geochemical elements could more widely regulate the diversity and community composition of prokaryotes than these of fungi.

  20. Macro and Microelements Drive Diversity and Composition of Prokaryotic and Fungal Communities in Hypersaline Sediments and Saline–Alkaline Soils

    Science.gov (United States)

    Liu, Kaihui; Ding, Xiaowei; Tang, Xiaofei; Wang, Jianjun; Li, Wenjun; Yan, Qingyun; Liu, Zhenghua

    2018-01-01

    Understanding the effects of environmental factors on microbial communities is critical for microbial ecology, but it remains challenging. In this study, we examined the diversity (alpha diversity) and community compositions (beta diversity) of prokaryotes and fungi in hypersaline sediments and salinized soils from northern China. Environmental variables were highly correlated, but they differed significantly between the sediments and saline soils. The compositions of prokaryotic and fungal communities in the hypersaline sediments were different from those in adjacent saline–alkaline soils, indicating a habitat-specific microbial distribution pattern. The macroelements (S, P, K, Mg, and Fe) and Ca were, respectively, correlated closely with the alpha diversity of prokaryotes and fungi, while the macronutrients (e.g., Na, S, P, and Ca) were correlated with the prokaryotic and fungal beta-diversity (P ≤ 0.05). And, the nine microelements (e.g., Al, Ba, Co, Hg, and Mn) and micronutrients (Ba, Cd, and Sr) individually shaped the alpha diversity of prokaryotes and fungi, while the six microelements (e.g., As, Ba, Cr, and Ge) and only the trace elements (Cr and Cu), respectively, influenced the beta diversity of prokaryotes and fungi (P analysis (VPA) showed that environmental variables jointly explained 55.49% and 32.27% of the total variation for the prokaryotic and fungal communities, respectively. Together, our findings demonstrate that the diversity and community composition of the prokaryotes and fungi were driven by different macro and microelements in saline habitats, and that geochemical elements could more widely regulate the diversity and community composition of prokaryotes than these of fungi. PMID:29535703

  1. Working for Equality and Diversity in Adult and Community Learning: Leadership, Representation and Racialised "Outsiders within"

    Science.gov (United States)

    Hunter, Shona

    2006-01-01

    This article uses empirical material from a qualitative study of adult and community learning (ACL) to explore issues around leading for equality and diversity in educational organisations. What the author is interested in is the way that the commitment to a "community" context in ACL opens up (or keeps open) certain possibilities for "diverse"…

  2. The world's richest tadpole communities show functional redundancy and low functional diversity: ecological data on Madagascar's stream-dwelling amphibian larvae

    Directory of Open Access Journals (Sweden)

    Randrianiaina Roger-Daniel

    2010-05-01

    Full Text Available Abstract Background Functional diversity illustrates the range of ecological functions in a community. It allows revealing the appearance of functional redundancy in communities and processes of community assembly. Functional redundancy illustrates the overlap in ecological functions of community members which may be an indicator of community resilience. We evaluated patterns of species richness, functional diversity and functional redundancy on tadpole communities in rainforest streams in Madagascar. This habitat harbours the world's most species-rich stream tadpole communities which are due to their occurrence in primary habitat of particular interest for functional diversity studies. Results Species richness of tadpole communities is largely determined by characteristics of the larval habitat (stream structure, not by adult habitat (forest structure. Species richness is positively correlated with a size-velocity gradient of the streams, i.e. communities follow a classical species-area relationship. While widely observed for other taxa, this is an unusual pattern for anuran larvae which usually is expected to be hump-shaped. Along the species richness gradient, we quantified functional diversity of all communities considering the similarity and dissimilarity of species in 18 traits related to habitat use and foraging. Especially species-rich communities were characterised by an overlap of species function, i.e. by functional redundancy. By comparing the functional diversity of the observed communities with functional diversity of random assemblages, we found no differences at low species richness level, whereas observed species-rich communities have lower functional diversity than respective random assemblages. Conclusions We found functional redundancy being a feature of communities also in primary habitat, what has not been shown before using such a continuous measure. The observed species richness dependent pattern of low functional

  3. Hydrogeochemical characteristics and bacterial community diversity in leachate from animal carcass disposal

    Science.gov (United States)

    Kaown, D.; Kim, H.; Lee, S.; Hyun, Y.; Moon, H.; Ko, K.; Lee, K.

    2012-12-01

    The release of leachate from animal carcass disposal can potentially contaminate soil and groundwater. During the Korea's foot-and-mouth disease (FMD) outbreak in 2010-2011, about 3.53 million of pigs and cattle were slaughtered and 4,538 burial sites were constructed. The objectives of this study are to determine the hydrogeochemical characteristics and bacterial community diversity in leachate from animal carcass disposal. Hydrogeochemical characteristics and bacterial community diversity in leachate from animal carcass burial facilities were monitored to prevent further soil and groundwater contamination and to build effective plans for stabilization of the burial site. Two burial sites were investigated in this study. An animal carcass disposal site is located in a flat area and another disposal site is found in mountain area. The hydrogeochemical and hydrogeological characteristics were analyzed to identify groundwater contamination by leachate from livestock burial sites. After 5-6 months of burial, the concentrations of NH4+, Cl-, and HCO3- in leachate were decreased since the leachate was regularly pumped and treated. However, high concentrations of major contaminants (NH4+, Cl-, and HCO3-) were still observed in landfill leachate of mountain area even though pumping and treatment of leachate were continuously conducted. Bacterial community diversity over time in leachate from animal carcass disposal was analyzed using 16S rRNA gene-based pyrosequencing. The impact of landfill leachate on change of bacterial community in soil and groundwater were monitored for a year.

  4. Functional Diversity of Fungal Communities in Soil Contaminated with Diesel Oil

    Directory of Open Access Journals (Sweden)

    Agata Borowik

    2017-09-01

    Full Text Available The widespread use and consumption of crude oil draws the public’s attention to the fate of petroleum hydrocarbons in the environment, as they can permeate the soil environment in an uncontrollable manner. Contamination of soils with petroleum products, including diesel oil (DO, can cause changes in the microbiological soil properties. The effect of diesel oil on the functional diversity of fungi was tested in a model experiment during 270 days. Fungi were isolated from soil and identified. The functional diversity of fungal communities was also determined. Fungi were identified with the MALDI-TOF method, while the functional diversity was determined using FF-plates made by Biolog®, with 95 carbon sources. Moreover, the diesel oil degradation dynamics was assessed. The research showed that soil contaminated with diesel oil is characterized by a higher activity of oxireductases and a higher number of fungi than soil not exposed to the pressure of this product. The DO pollution has an adverse effect on the diversity of fungal community. This is proved by significantly lower values of the Average Well-Color Development, substrates Richness (R and Shannon–Weaver (H indices at day 270 after contamination. The consequences of DO affecting soil not submitted to remediation are persistent. After 270 days, only 64% of four-ringed, 28% of five-ringed, 21% of 2–3-ringed and 16% of six-ringed PAHs underwent degradation. The lasting effect of DO on communities of fungi led to a decrease in their functional diversity. The assessment of the response of fungi to DO pollution made on the basis of the development of colonies on Petri dishes [Colony Development (CD and Eco-physiological Diversity (EP indices] is consistent with the analysis based on the FF MicroPlate system by Biolog®. Thus, a combination of the FF MicroPlate system by Biolog® with the simultaneous calculation of CD and EP indices alongside the concurrent determination of the content of

  5. High shrew diversity on Alaska's Seward Peninsula: Community assembly and environmental change

    Science.gov (United States)

    Hope, Andrew G.

    2012-01-01

    In September 2010, 6 species of shrews (genus: Sorex) were collected at a single locality on the Seward Peninsula of Alaska. Such high sympatric diversity within a single mammalian genus is seldom realized. This phenomenon at high latitudes highlights complex Arctic community dynamics that reflect significant turnover through time as a consequence of environmental change. Each of these shrew species occupies a broad geographic distribution collectively spanning the entire Holarctic, although the study site lies within Eastern Beringia, near the periphery of all individual ranges. A review of published genetic evidence reflects a depauperate shrew community within ice-free Beringia through the last glaciation, and recent assembly of current diversity during the Holocene.

  6. Barriers and Facilitators to Community Mobility for Assistive Technology Users

    Directory of Open Access Journals (Sweden)

    Natasha Layton

    2012-01-01

    Full Text Available Mobility is frequently described in terms of individual body function and structures however contemporary views of disability also recognise the role of environment in creating disability. Aim. To identify consumer perspectives regarding barriers and facilitators to optimal mobility for a heterogeneous population of impaired Victorians who use assistive technology in their daily lives. Method. An accessible survey investigated the impact of supports or facilitators upon actual and desired life outcomes and health-related quality of life, from 100 AT users in Victoria, Australia. This paper reports upon data pertaining to community mobility. Results. A range of barriers and enablers to community mobility were identified including access to AT devices, environmental interventions, public transport, and inclusive community environs. Substantial levels of unmet need result in limited personal mobility and community participation. Outcomes fall short of many principles enshrined in current policy and human rights frameworks. Conclusion. AT devices as well as accessible and inclusive home and community environs are essential to maximizing mobility for many. Given the impact of the environment upon the capacity of individuals to realise community mobility, this raises the question as to whether rehabilitation practitioners, as well as prescribing AT devices, should work to build accessible communities via systemic advocacy.

  7. Guidelines for NASA Missions to Engage the User Community as a Part of the Mission Life Cycle

    Science.gov (United States)

    Escobar, V. M.; Friedl, L.; Bonniksen, C. K.

    2017-12-01

    NASA continues to improve the Earth Science Directorate in the areas of thematic integration, stakeholder feedback and Project Applications Program tailoring for missions to transfer knowledge between scientists and projects. The integration of application themes and the implementation of application science activities in flight projects have evolved to formally include user feedback and stakeholder integration. NASA's new Flight Applied Science Program Guidelines are designed to bridge NASA Earth Science Directorates in Flight, Applied Sciences and Research and Development by agreeing to integrate the user community into mission life cycles. Thus science development and science applications will guide all new instruments launched by NASAs ESD. The continued integration with the user community has enabled socio-economic considerations into NASA Earth Science projects to advance significantly. Making users a natural part of mission science leverages future socio-economic impact research and provides a platform for innovative and more actionable product to be used in decision support systems by society. This presentation will give an overview of the new NASA Guidelines and provide samples that demonstrate how the user community can be a part of NASA mission designs.

  8. Impact of Lowland Rainforest Transformation on Diversity and Composition of Soil Prokaryotic Communities in Sumatra (Indonesia)

    Science.gov (United States)

    Schneider, Dominik; Engelhaupt, Martin; Allen, Kara; Kurniawan, Syahrul; Krashevska, Valentyna; Heinemann, Melanie; Nacke, Heiko; Wijayanti, Marini; Meryandini, Anja; Corre, Marife D.; Scheu, Stefan; Daniel, Rolf

    2015-01-01

    Prokaryotes are the most abundant and diverse group of microorganisms in soil and mediate virtually all biogeochemical cycles in terrestrial ecosystems. Thereby, they influence aboveground plant productivity and diversity. In this study, the impact of rainforest transformation to intensively managed cash crop systems on soil prokaryotic communities was investigated. The studied managed land use systems comprised rubber agroforests (jungle rubber), rubber plantations and oil palm plantations within two Indonesian landscapes Bukit Duabelas and Harapan. Soil prokaryotic community composition and diversity were assessed by pyrotag sequencing of bacterial and archaeal 16S rRNA genes. The curated dataset contained 16,413 bacterial and 1679 archaeal operational taxonomic units at species level (97% genetic identity). Analysis revealed changes in indigenous taxon-specific patterns of soil prokaryotic communities accompanying lowland rainforest transformation to jungle rubber, and intensively managed rubber and oil palm plantations. Distinct clustering of the rainforest soil communities indicated that these are different from the communities in the studied managed land use systems. The predominant bacterial taxa in all investigated soils were Acidobacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Overall, the bacterial community shifted from proteobacterial groups in rainforest soils to Acidobacteria in managed soils. The archaeal soil communities were mainly represented by Thaumarchaeota and Euryarchaeota. Members of the Terrestrial Group and South African Gold Mine Group 1 (Thaumarchaeota) dominated in the rainforest and members of Thermoplasmata in the managed land use systems. The alpha and beta diversity of the soil prokaryotic communities was higher in managed land use systems than in rainforest. In the case of bacteria, this was related to soil characteristics such as pH value, exchangeable Ca and Fe content, C to N ratio

  9. Impact of lowland rainforest transformation on diversity and composition of soil prokaryotic communities in Sumatra (Indonesia

    Directory of Open Access Journals (Sweden)

    Dominik eSchneider

    2015-12-01

    Full Text Available Prokaryotes are the most abundant and diverse group of microorganisms in soil and mediate virtually all biogeochemical cycles in terrestrial ecosystems. Thereby, they influence aboveground plant productivity and diversity. In this study, the impact of rainforest transformation to intensively managed cash crop systems on soil prokaryotic communities was investigated. The studied managed land use system comprised rubber agroforests (jungle rubber, rubber plantation and oil plantations within two Indonesian landscapes Bukit Duabelas and Harapan. Soil prokaryotic community composition and diversity were assessed by pyrotag sequencing of bacterial and archaeal 16S rRNA genes. The curated dataset contained 20,494 bacterial and 1,762 archaeal Operational Taxonomic Units at species level (97% genetic identity. Analysis revealed changes in indigenous taxon-specific patterns of soil prokaryotic communities accompanying lowland rainforest transformation to jungle rubber, and intensively managed rubber and oil palm plantations. Distinct clustering of the rainforest soil communities indicated that these are different from the communities in the studied managed land use systems. The predominant bacterial taxa in all investigated soils were Acidobacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Overall, the bacterial community shifted from proteobacterial groups in rainforest soils to Acidobacteria in managed soils. The archaeal soil communities were mainly represented by Thaumarchaeota and Euryarchaeota. Members of the Terrestrial Group and South African Gold Mine Group 1 (Thaumarchaeota dominated in the rainforest and members of Thermoplasmata in the managed land use systems. The alpha and beta diversity of the soil prokaryotic communities was higher in managed land use systems than in rainforest. In the case of bacteria, this was related to soil characteristics such as pH value, exchangeable Ca and Fe content, C to

  10. Rapid colonization of a Hawaiian restoration forest by a diverse avian community

    Science.gov (United States)

    Paxton, Eben H.; Yelenik, Stephanie G.; Borneman, Tracy E.; Rose, Eli; Camp, Richard J.; Kendall, Steve J.

    2018-01-01

    Deforestation of tropical forests has led to widespread loss and extirpation of forest bird species around the world, including the Hawaiian Islands which have experienced a dramatic loss of forests over the last 200–800 years. Given the important role birds play in forest ecosystem functions via seed dispersal and pollination, a bird community's response to forest restoration is an important measure of the success of such conservation actions. We evaluated the bird response to reforestation at an important bird sanctuary, Hakalau Forest National Wildlife Refuge, Hawai′i Island, using 26 years of bird count data. We show that most species from within the diverse avian community increased significantly, but species colonized the restoration forest at different rates. Distance from intact forest and time since restoration were both important predictors of colonization rate, interacting such that for most species it took more time to colonize areas farther from the intact forest. In addition, both forest cover and understory diversity helped to explain bird densities, but the effect varied among species, suggesting that different habitat requirements may help drive variation in colonization rates. This article provides the first detailed evaluation of how a diverse community of birds has responded to one of the largest, ongoing reforestation projects in Hawai′i.

  11. Functional diversity and redundancy across fish gut, sediment and water bacterial communities.

    Science.gov (United States)

    Escalas, Arthur; Troussellier, Marc; Yuan, Tong; Bouvier, Thierry; Bouvier, Corinne; Mouchet, Maud A; Flores Hernandez, Domingo; Ramos Miranda, Julia; Zhou, Jizhong; Mouillot, David

    2017-08-01

    This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (β) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Boom clay pore water, home of a diverse microbial community

    International Nuclear Information System (INIS)

    Wouters, Katinka; Moors, Hugo; Leys, Natalie

    2012-01-01

    Document available in extended abstract form only. Boom Clay pore water (BCPW) has been studied in the framework of geological disposal of nuclear waste for over two decades, thereby mainly addressing its geochemical properties. A reference composition for synthetic clay water has been derived earlier by modelling and spatial calibration efforts, mainly based on interstitial water sampled from different layers within the Boom clay. However, since microbial activity is found in a range of extreme circumstances, the possibility of microbes interacting with future radioactive waste in a host formation like Boom Clay, cannot be ignored. In this respect, BCPW was sampled from different Boom Clay layers using the Morpheus piezometer and subsequently analysed by a complementary set of microbiological and molecular techniques, in search for overall shared and abundant microorganisms. Similar to the previous characterization of the 'average' BCPW chemical composition, the primary aim of this microbiological study is to determine a representative BCPW microbial community which can be used in laboratory studies. Secondly, the in situ activity and the metabolic properties of members of this community were addressed, aiming to assess their survival and proliferation chances in repository conditions. In a first approach, total microbial DNA of the community was extracted from the BCPW samples. This molecular approach allows a broad insight in the total microbial ecology of the BCPW samples. By polymerase chain reaction (PCR) on the highly conserved 16S rRNA genes in this DNA pool and subsequent sequencing and bio-informatics analysis, operational taxonomic units (OTUs) could be assigned to the microbial community. The bacterial community was found to be quite diverse, with OTUs belonging to 8 different phyla (Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Chlorobi, Spirochetes, Chloroflexi and Deinococcus-Thermus). These results provide an overall view of the

  13. Boom clay pore water, home of a diverse microbial community

    Energy Technology Data Exchange (ETDEWEB)

    Wouters, Katinka; Moors, Hugo; Leys, Natalie [SCK.CEN, Environment, Health and Safety Institute, B-2400 Mol (Belgium)

    2012-10-15

    Document available in extended abstract form only. Boom Clay pore water (BCPW) has been studied in the framework of geological disposal of nuclear waste for over two decades, thereby mainly addressing its geochemical properties. A reference composition for synthetic clay water has been derived earlier by modelling and spatial calibration efforts, mainly based on interstitial water sampled from different layers within the Boom clay. However, since microbial activity is found in a range of extreme circumstances, the possibility of microbes interacting with future radioactive waste in a host formation like Boom Clay, cannot be ignored. In this respect, BCPW was sampled from different Boom Clay layers using the Morpheus piezometer and subsequently analysed by a complementary set of microbiological and molecular techniques, in search for overall shared and abundant microorganisms. Similar to the previous characterization of the 'average' BCPW chemical composition, the primary aim of this microbiological study is to determine a representative BCPW microbial community which can be used in laboratory studies. Secondly, the in situ activity and the metabolic properties of members of this community were addressed, aiming to assess their survival and proliferation chances in repository conditions. In a first approach, total microbial DNA of the community was extracted from the BCPW samples. This molecular approach allows a broad insight in the total microbial ecology of the BCPW samples. By polymerase chain reaction (PCR) on the highly conserved 16S rRNA genes in this DNA pool and subsequent sequencing and bio-informatics analysis, operational taxonomic units (OTUs) could be assigned to the microbial community. The bacterial community was found to be quite diverse, with OTUs belonging to 8 different phyla (Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Chlorobi, Spirochetes, Chloroflexi and Deinococcus-Thermus). These results provide an overall view of the

  14. Land-use systems affect Archaeal community structure and functional diversity in western Amazon soils

    Directory of Open Access Journals (Sweden)

    Acácio Aparecido Navarrete

    2011-10-01

    Full Text Available The study of the ecology of soil microbial communities at relevant spatial scales is primordial in the wide Amazon region due to the current land use changes. In this study, the diversity of the Archaea domain (community structure and ammonia-oxidizing Archaea (richness and community composition were investigated using molecular biology-based techniques in different land-use systems in western Amazonia, Brazil. Soil samples were collected in two periods with high precipitation (March 2008 and January 2009 from Inceptisols under primary tropical rainforest, secondary forest (5-20 year old, agricultural systems of indigenous people and cattle pasture. Denaturing gradient gel electrophoresis of polymerase chain reaction-amplified DNA (PCR-DGGE using the 16S rRNA gene as a biomarker showed that archaeal community structures in crops and pasture soils are different from those in primary forest soil, which is more similar to the community structure in secondary forest soil. Sequence analysis of excised DGGE bands indicated the presence of crenarchaeal and euryarchaeal organisms. Based on clone library analysis of the gene coding the subunit of the enzyme ammonia monooxygenase (amoA of Archaea (306 sequences, the Shannon-Wiener function and Simpson's index showed a greater ammonia-oxidizing archaeal diversity in primary forest soils (H' = 2.1486; D = 0.1366, followed by a lower diversity in soils under pasture (H' = 1.9629; D = 0.1715, crops (H' = 1.4613; D = 0.3309 and secondary forest (H' = 0.8633; D = 0.5405. All cloned inserts were similar to the Crenarchaeota amoA gene clones (identity > 95 % previously found in soils and sediments and distributed primarily in three major phylogenetic clusters. The findings indicate that agricultural systems of indigenous people and cattle pasture affect the archaeal community structure and diversity of ammonia-oxidizing Archaea in western Amazon soils.

  15. Genetic Diversity of Bacterial Communities and Gene Transfer Agents in Northern South China Sea

    Science.gov (United States)

    Sun, Fu-Lin; Wang, You-Shao; Wu, Mei-Lin; Jiang, Zhao-Yu; Sun, Cui-Ci; Cheng, Hao

    2014-01-01

    Pyrosequencing of the 16S ribosomal RNA gene (rDNA) amplicons was performed to investigate the unique distribution of bacterial communities in northern South China Sea (nSCS) and evaluate community structure and spatial differences of bacterial diversity. Cyanobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes constitute the majority of bacteria. The taxonomic description of bacterial communities revealed that more Chroococcales, SAR11 clade, Acidimicrobiales, Rhodobacterales, and Flavobacteriales are present in the nSCS waters than other bacterial groups. Rhodobacterales were less abundant in tropical water (nSCS) than in temperate and cold waters. Furthermore, the diversity of Rhodobacterales based on the gene transfer agent (GTA) major capsid gene (g5) was investigated. Four g5 gene clone libraries were constructed from samples representing different regions and yielded diverse sequences. Fourteen g5 clusters could be identified among 197 nSCS clones. These clusters were also related to known g5 sequences derived from genome-sequenced Rhodobacterales. The composition of g5 sequences in surface water varied with the g5 sequences in the sampling sites; this result indicated that the Rhodobacterales population could be highly diverse in nSCS. Phylogenetic tree analysis result indicated distinguishable diversity patterns among tropical (nSCS), temperate, and cold waters, thereby supporting the niche adaptation of specific Rhodobacterales members in unique environments. PMID:25364820

  16. Community composition and diversity of ground beetles (Coleoptera: Carabidae) in Yaoluoping National Nature Reserve

    Science.gov (United States)

    Li, Wen-Bo; Liu, Nai-Yi; Wu, Yun-He; Zhang, Yu-Cai; Xu, Qin; Chu, Jun; Wang, Shu-Yan

    2017-01-01

    Abstract This study used pitfall trapping to examine community composition and diversity of ground beetles in five different habitats (coniferous, deciduous, mixed coniferous, farmland, and settlements) within Anhui Yaoluoping National Nature Reserve from May to September 2014. In total, 1,352 ground beetles were collected, belonging to 16 genera and 44 species. Of these, four dominant species Dolichus halensis, Harpalus pastor, Carabus casaleianus, and Pheropsophus jessoensis were identified, respectively, comprising 370, 177, 131, and 123 individuals. The deciduous forest showed greater diversity (3.78 according to Shannon–Weiner index), equitability (0.80 according to Pielou’s index), and dominance (9.52 according to Simpson’s index) when compared with farmland, but species richness in the deciduous forest (27) was lower than that in farmland (35). One-way analysis of variance showed that ground beetle species composition and abundance among different habitats varied significantly. Cluster analysis and principal coordinate analysis showed that farmland shared low community similarity with other habitat types, and coniferous and mixed coniferous forests shared similar community types. Our results indicate that species composition, abundance, and diversity of ground beetles are affected by different habitat types, with deciduous forest types being critical in maintaining the diversity of rare species. We recommend reducing cultivated farmland area and increasing the area of carefully planned deciduous forest in order to better protect ground beetle diversity in the region.

  17. The veterinary antibiotic oxytetracycline and Cu influence functional diversity of the soil microbial community

    Energy Technology Data Exchange (ETDEWEB)

    Kong, W -D [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhu, Y -G [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Fu, B -J [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Marschner, P [Soil and Land Systems, School of Earth and Environmental Sciences, University of Adelaide, DP 636, 5005 (Australia); He, J -Z [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)

    2006-09-15

    There are increasing concerns over the effects of veterinary antibiotics and heavy metals in agricultural soils. The widely used veterinary antibiotic oxytetracycline (OTC), Cu and their combination on soil microbial community function were assessed with the Biolog method. The microbial community was extracted from the soil and exposed to a 0.85% sodium chloride solution containing OTC (0, 1, 5, 11, 43, 109 and 217 {mu}M), or Cu (0, 10, 20, 100 and 300 {mu}M), or combination of the two pollutants (OTC 0, 5, 11 {mu}M and Cu 0, 20 {mu}M). Functional diversity, evenness, average well color development (AWCD) and substrate utilization decreased significantly with increasing concentrations of OTC or Cu (p < 0.005). The critical concentrations were 11 {mu}M for OTC and 20 {mu}M for Cu. The combination of OTC and Cu significantly decreased Shannon's diversity, evenness and utilization of carbohydrates and carboxylic acids compared to individual one of the contaminants. The antibiotic OTC and Cu had significant negative effects on soil microbial community function, particularly when both pollutants were present. - Oxytetracycline reduces the functional diversity of soil microbial community, and the combination of Cu and oxytetracycline leads to a further reduction.

  18. The veterinary antibiotic oxytetracycline and Cu influence functional diversity of the soil microbial community

    International Nuclear Information System (INIS)

    Kong, W.-D.; Zhu, Y.-G.; Fu, B.-J.; Marschner, P.; He, J.-Z.

    2006-01-01

    There are increasing concerns over the effects of veterinary antibiotics and heavy metals in agricultural soils. The widely used veterinary antibiotic oxytetracycline (OTC), Cu and their combination on soil microbial community function were assessed with the Biolog method. The microbial community was extracted from the soil and exposed to a 0.85% sodium chloride solution containing OTC (0, 1, 5, 11, 43, 109 and 217 μM), or Cu (0, 10, 20, 100 and 300 μM), or combination of the two pollutants (OTC 0, 5, 11 μM and Cu 0, 20 μM). Functional diversity, evenness, average well color development (AWCD) and substrate utilization decreased significantly with increasing concentrations of OTC or Cu (p < 0.005). The critical concentrations were 11 μM for OTC and 20 μM for Cu. The combination of OTC and Cu significantly decreased Shannon's diversity, evenness and utilization of carbohydrates and carboxylic acids compared to individual one of the contaminants. The antibiotic OTC and Cu had significant negative effects on soil microbial community function, particularly when both pollutants were present. - Oxytetracycline reduces the functional diversity of soil microbial community, and the combination of Cu and oxytetracycline leads to a further reduction

  19. Parallel community climate model: Description and user`s guide

    Energy Technology Data Exchange (ETDEWEB)

    Drake, J.B.; Flanery, R.E.; Semeraro, B.D.; Worley, P.H. [and others

    1996-07-15

    This report gives an overview of a parallel version of the NCAR Community Climate Model, CCM2, implemented for MIMD massively parallel computers using a message-passing programming paradigm. The parallel implementation was developed on an Intel iPSC/860 with 128 processors and on the Intel Delta with 512 processors, and the initial target platform for the production version of the code is the Intel Paragon with 2048 processors. Because the implementation uses a standard, portable message-passing libraries, the code has been easily ported to other multiprocessors supporting a message-passing programming paradigm. The parallelization strategy used is to decompose the problem domain into geographical patches and assign each processor the computation associated with a distinct subset of the patches. With this decomposition, the physics calculations involve only grid points and data local to a processor and are performed in parallel. Using parallel algorithms developed for the semi-Lagrangian transport, the fast Fourier transform and the Legendre transform, both physics and dynamics are computed in parallel with minimal data movement and modest change to the original CCM2 source code. Sequential or parallel history tapes are written and input files (in history tape format) are read sequentially by the parallel code to promote compatibility with production use of the model on other computer systems. A validation exercise has been performed with the parallel code and is detailed along with some performance numbers on the Intel Paragon and the IBM SP2. A discussion of reproducibility of results is included. A user`s guide for the PCCM2 version 2.1 on the various parallel machines completes the report. Procedures for compilation, setup and execution are given. A discussion of code internals is included for those who may wish to modify and use the program in their own research.

  20. Exploring engagement in a virtual community of practice in pediatric rehabilitation: who are non-users, lurkers, and posters?

    Science.gov (United States)

    Hurtubise, Karen; Pratte, Gabrielle; Rivard, Lisa; Berbari, Jade; Héguy, Léa; Camden, Chantal

    2017-12-20

    Communities of practice are increasingly recognized in rehabilitation as useful knowledge transfer tools; however, little is known about their users. This exploratory study describes the characteristics of participants and non-participants invited to engage in a pediatric rehabilitation virtual community of practice. In addition, we explored virtual community of practice utilization behaviors, engagement predictors, and the impact of strategies designed to foster engagement. Participants' demographics including information-seeking style and organization e-readiness, as well as online platform frequency of use data were collected and analyzed using descriptive, comparative, and predictive statistics. Seventy-four percent of those invited used the virtual community of practice. Users had less years of experience in pediatric rehabilitation than non-users. Among the users, 71% were classified as "lurkers," who engaged through reading content only; while 29% were classified as "posters," editing online content. Predictive factors were not uncovered, however an increased number of forum visits correlated with being a poster, a non-information seeker, an employee of an organization demonstrating e-readiness, and regularly working with children with the virtual community of practice specific condition. User-engagement strategies increased visits to the forum. These findings will assist rehabilitation leaders in leveraging rehabilitation-specific virtual community of practice to improve knowledge transfer and practice in pediatric rehabilitation and disability management. Implications for Rehabilitation Communities of practice are increasingly recognized as useful knowledge transfer tools for rehabilitation professionals and are made more accessible thanks to virtual technologies. Our virtual community of practice was found to be optimized in health care organizations with an electronic culture, when the topic area had daily relevance to its target audience, and was

  1. Disentangling the diversity of arboreal ant communities in tropical forest trees.

    Science.gov (United States)

    Klimes, Petr; Fibich, Pavel; Idigel, Cliffson; Rimandai, Maling

    2015-01-01

    Tropical canopies are known for their high abundance and diversity of ants. However, the factors which enable coexistence of so many species in trees, and in particular, the role of foragers in determining local diversity, are not well understood. We censused nesting and foraging arboreal ant communities in two 0.32 ha plots of primary and secondary lowland rainforest in New Guinea and explored their species diversity and composition. Null models were used to test if the records of species foraging (but not nesting) in a tree were dependent on the spatial distribution of nests in surrounding trees. In total, 102 ant species from 389 trees occurred in the primary plot compared with only 50 species from 295 trees in the secondary forest plot. However, there was only a small difference in mean ant richness per tree between primary and secondary forest (3.8 and 3.3 sp. respectively) and considerably lower richness per tree was found only when nests were considered (1.5 sp. in both forests). About half of foraging individuals collected in a tree belonged to species which were not nesting in that tree. Null models showed that the ants foraging but not nesting in a tree are more likely to nest in nearby trees than would be expected at random. The effects of both forest stage and tree size traits were similar regardless of whether only foragers, only nests, or both datasets combined were considered. However, relative abundance distributions of species differed between foraging and nesting communities. The primary forest plot was dominated by native ant species, whereas invasive species were common in secondary forest. This study demonstrates the high contribution of foragers to arboreal ant diversity, indicating an important role of connectivity between trees, and also highlights the importance of primary vegetation for the conservation of native ant communities.

  2. Species diversity, vegetation pattern and conservation of Gentiana macrophylla Pall. communities in Dongling mountain meadow, Beijing, China

    International Nuclear Information System (INIS)

    Sadia, S.; Zhang, J.T.; Bai, X.; Shedayi, A.A.; Tariq, A.

    2017-01-01

    Gentiana macrophylla, native to mountainous areas of Central and Southern Asia, is most popular remedy for rheumatism and pains in Traditional Chinese Medicine with an extensive demand in local market. Our study aimed to classify G. macrophylla communities and to find out the impact of topographic and soil factors on their diversity and distribution in Dongling mountain meadow, Beijing, China. Seventy five samples in 15 transects separated by 50m distance in altitude along an elevation gradient (1592-2298m) were established by quadrate method. TWINSAPN and CCA were used for classification and ordination, respectively. Six diversity indices (Species richness, Shannon-Weiner heterogeneity, Simpson’s index, Hill’s index, Pielou evenness and McIntosh evenness) were used to analyze the pattern of species diversity and polynomial regression analysis was used to establish their relationship with environmental variables. TWINSPAN classified G. macrophylla communities into 8 types and CCA indicated that soil pH, soil temperature, soil type, disturbance, total N, total K, Mg and Zn were significantly related to these communities. Elevation was the most significant factor that affecting the diversity and distribution of G. macrophylla communities. Significant effect of environment, topography and disturbance to meadow communities of G. macrophylla highly suggests some important measures such as uprooting restriction, tourism limitation in meadow area, monitoring of functional diversity, fertilization, irrigation, cloning and cultivation to protect and conserve it and its communities to be used in medicine industry. (author)

  3. Beware of Geeks Bearing Gifts - Are we Meeting the Requirements of our User Communities?

    Science.gov (United States)

    Klump, J.

    2007-12-01

    The 20th century brought about an "information revolution" that has forever altered the way we work, communicate, and live. The way science has been conducted for the past 200 years has been challenged by new media of communication and for the dissemination of data. We now have the tools at hand, commonly called cyberinfrastructure, that enable new forms of global collaboration. But are we fully realising the potential of cyberinfrastructure? Has it become an integral part of our scientific culture? Tools developed in Earth and Space Science Informatics projects suffer the same effects like informatics developments in other fields. Many of the projects fail to meet user requirements, and they do so for a number of reasons. Besides a certain reluctance on the side of scientists to adopt new tools for conducting their research, many cyberinfrastructure projects suffer from "marketing myopia" (Levitt, 1960) in the way they try to "sell" their applications. According to Levitt, the difference between selling and marketing is that the former fulfils the needs of the seller and the latter the needs of the buyer. Cyberinfrastructure projects must stop trying to sell their achievements to the scientific community, and instead market them by considering the scientists" needs right at the beginning of their endeavours. Admittedly, the requirements of scientific user communities are "moving targets", because scientific workflows are often subject to ad-hoc changes, depending on the outcome of the preceding step. Another important risk factor, faced by many cyberinfrastructure projects, is that the designated user community is not aware of the availability of this new resource. This is where training and outreach are essential, especially to draw in early adopters of new technology and multipliers among researchers. Only cyberinfrastructure tools that truly serve their designated user community will eventually become part of the scientific infrastructure. This presentation

  4. Phylogenetic diversity, host-specificity and community profiling of sponge-associated bacteria in the northern Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    Patrick M Erwin

    Full Text Available Marine sponges can associate with abundant and diverse consortia of microbial symbionts. However, associated bacteria remain unexamined for the majority of host sponges and few studies use phylogenetic metrics to quantify symbiont community diversity. DNA fingerprinting techniques, such as terminal restriction fragment length polymorphisms (T-RFLP, might provide rapid profiling of these communities, but have not been explicitly compared to traditional methods.We investigated the bacterial communities associated with the marine sponges Hymeniacidon heliophila and Haliclona tubifera, a sympatric tunicate, Didemnum sp., and ambient seawater from the northern Gulf of Mexico by combining replicated clone libraries with T-RFLP analyses of 16S rRNA gene sequences. Clone libraries revealed that bacterial communities associated with the two sponges exhibited lower species richness and lower species diversity than seawater and tunicate assemblages, with differences in species composition among all four source groups. T-RFLP profiles clustered microbial communities by source; individual T-RFs were matched to the majority (80.6% of clone library sequences, indicating that T-RFLP analysis can be used to rapidly profile these communities. Phylogenetic metrics of community diversity indicated that the two sponge-associated bacterial communities include dominant and host-specific bacterial lineages that are distinct from bacteria recovered from seawater, tunicates, and unrelated sponge hosts. In addition, a large proportion of the symbionts associated with H. heliophila were shared with distant, conspecific host populations in the southwestern Atlantic (Brazil.The low diversity and species-specific nature of bacterial communities associated with H. heliophila and H. tubifera represent a distinctly different pattern from other, reportedly universal, sponge-associated bacterial communities. Our replicated sampling strategy, which included samples that reflect the

  5. Communities of microbial eukaryotes in the mammalian gut within the context of environmental eukaryotic diversity

    Energy Technology Data Exchange (ETDEWEB)

    Parfrey, Laura Wegener; Walters, William A.; Lauber, Christian L.; Clemente, Jose C.; Berg-Lyons, Donna; Teiling, Clotilde; Kodira, Chinnappa; Mohiuddin, Mohammed; Brunelle, Julie; Driscoll, Mark; Fierer, Noah; Gilbert, Jack A.; Knight, Rob

    2014-06-19

    Eukaryotic microbes (protists) residing in the vertebrate gut influence host health and disease, but their diversity and distribution in healthy hosts is poorly understood. Protists found in the gut are typically considered parasites, but many are commensal and some are beneficial. Further, the hygiene hypothesis predicts that association with our co-evolved microbial symbionts may be important to overall health. It is therefore imperative that we understand the normal diversity of our eukaryotic gut microbiota to test for such effects and avoid eliminating commensal organisms. We assembled a dataset of healthy individuals from two populations, one with traditional, agrarian lifestyles and a second with modern, westernized lifestyles, and characterized the human eukaryotic microbiota via high-throughput sequencing. To place the human gut microbiota within a broader context our dataset also includes gut samples from diverse mammals and samples from other aquatic and terrestrial environments. We curated the SILVA ribosomal database to reflect current knowledge of eukaryotic taxonomy and employ it as a phylogenetic framework to compare eukaryotic diversity across environment. We show that adults from the non-western population harbor a diverse community of protists, and diversity in the human gut is comparable to that in other mammals. However, the eukaryotic microbiota of the western population appears depauperate. The distribution of symbionts found in mammals reflects both host phylogeny and diet. Eukaryotic microbiota in the gut are less diverse and more patchily distributed than bacteria. More broadly, we show that eukaryotic communities in the gut are less diverse than in aquatic and terrestrial habitats, and few taxa are shared across habitat types, and diversity patterns of eukaryotes are correlated with those observed for bacteria. These results outline the distribution and diversity of microbial eukaryotic communities in the mammalian gut and across

  6. Diversity effects on root length production and loss in an experimental grassland community

    NARCIS (Netherlands)

    Mommer, L.; Padilla, F.M.; Ruijven, van J.; Caluwe, de H.; Smit-Tiekstra, A.E.; Berendse, F.; Kroon, de H.

    2015-01-01

    Advances in root ecology have revealed that root standing biomass is higher in species-rich plant communities than in species-poor communities. Currently, we do not know whether this below-ground diversity effect is the result of enhanced root production or reduced root mortality or both, which is

  7. Diverse coral communities in naturally acidified waters of a Western Pacific reef

    Science.gov (United States)

    Shamberger, Kathryn E. F.; Cohen, Anne L.; Golbuu, Yimnang; McCorkle, Daniel C.; Lentz, Steven J.; Barkley, Hannah C.

    2014-01-01

    Anthropogenic carbon dioxide emissions are acidifying the oceans, reducing the concentration of carbonate ions ([CO32-]) that calcifying organisms need to build and cement coral reefs. To date, studies of a handful of naturally acidified reef systems reveal depauperate communities, sometimes with reduced coral cover and calcification rates, consistent with results of laboratory-based studies. Here we report the existence of highly diverse, coral-dominated reef communities under chronically low pH and aragonite saturation state (Ωar). Biological and hydrographic processes change the chemistry of the seawater moving across the barrier reefs and into Palau's Rock Island bays, where levels of acidification approach those projected for the western tropical Pacific open ocean by 2100. Nevertheless, coral diversity, cover, and calcification rates are maintained across this natural acidification gradient. Identifying the combination of biological and environmental factors that enable these communities to persist could provide important insights into the future of coral reefs under anthropogenic acidification.

  8. Diversity of macrofungal community in Bifeng Gorge: the core giant ...

    African Journals Online (AJOL)

    Macrofungi not only play an important role in pollution control and other environmental protection measures, but also an important resource in food and pharmaceutical industries. However, the diversity of the macrofungal community in the core habitat of the giant panda in Bifeng Gorge, China is still inadequate. In the ...

  9. Exploring Diversity in Higher Education Management: History, Trends, and Implications for Community Colleges

    Science.gov (United States)

    Robinson-Neal, Andree

    2009-01-01

    As college and university campuses direct their efforts to include more diverse populations of students, campus leaders must consider whether there is merit in having a diverse population of administrators as well. The issue is of particular importance to the community college sector, since it is a primary point of entry into higher education for…

  10. Spatial scaling of bacterial community diversity at shallow hydrothermal vents: a global comparison

    Science.gov (United States)

    Pop Ristova, P.; Hassenrueck, C.; Molari, M.; Fink, A.; Bühring, S. I.

    2016-02-01

    Marine shallow hydrothermal vents are extreme environments, often characterized by discharge of fluids with e.g. high temperatures, low pH, and laden with elements toxic to higher organisms. They occur at continental margins around the world's oceans, but represent fragmented, isolated habitats of locally small areal coverage. Microorganisms contribute the main biomass at shallow hydrothermal vent ecosystems and build the basis of the food chain by autotrophic fixation of carbon both via chemosynthesis and photosynthesis, occurring simultaneously. Despite their importance and unique capacity to adapt to these extreme environments, little is known about the spatial scales on which the alpha- and beta-diversity of microbial communities vary at shallow vents, and how the geochemical habitat heterogeneity influences shallow vent biodiversity. Here for the first time we investigated the spatial scaling of microbial biodiversity patterns and their interconnectivity at geochemically diverse shallow vents on a global scale. This study presents data on the comparison of bacterial community structures on large (> 1000 km) and small (0.1 - 100 m) spatial scales as derived from ARISA and Illumina sequencing. Despite the fragmented global distribution of shallow hydrothermal vents, similarity of vent bacterial communities decreased with geographic distance, confirming the ubiquity of distance-decay relationship. Moreover, at all investigated vents, pH was the main factor locally structuring these communities, while temperature influenced both the alpha- and beta-diversity.

  11. Color me healthy: food diversity in school community gardens in two rapidly urbanising Australian cities.

    Science.gov (United States)

    Guitart, Daniela A; Pickering, Catherine M; Byrne, Jason A

    2014-03-01

    Community garden research has focused on social aspects of gardens, neglecting systematic analysis of what food is grown. Yet agrodiversity within community gardens may provide health benefits. Diverse fruit and vegetables provide nutritional benefits, including vitamins, minerals and phytochemicals. This paper reports research that investigated the agro-biodiversity of school-based community gardens in Brisbane and Gold Coast cities, Australia. Common motivations for establishing these gardens were education, health and environmental sustainability. The 23 gardens assessed contained 234 food plants, ranging from 7 to 132 plant types per garden. This included 142 fruits and vegetables. The nutritional diversity of fruits and vegetable plants was examined through a color classification system. All gardens grew fruits and vegetables from at least four food color groups, and 75% of the gardens grew plants from all seven color groups. As places with high agrodiversity, and related nutritional diversity, some school community gardens can provide children with exposure to a healthy range of fruit and vegetables, with potential flow-on health benefits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Different in the dark: The effect of habitat characteristics on community composition and beta diversity in bromeliad microfauna.

    Directory of Open Access Journals (Sweden)

    Annika Busse

    Full Text Available The mechanisms which structure communities have been the focus of a large body of research. Here, we address the question if habitat characteristics describing habitat quality may drive changes in community composition and beta diversity of bromeliad-inhabiting microfauna. In our system, changes in canopy cover along an environmental gradient may affect resource availability, disturbance in form of daily water temperature fluctuations and predation, and thus may lead to changes in community structure of bromeliad microfauna through differences in habitat quality along this gradient. Indeed, we observed distinct changes in microfauna community composition along the environmental gradient explained by changes in the extent of daily water temperature fluctuations. We found beta diversity to be higher under low habitat quality (low canopy cover than under high habitat quality (high canopy cover, which could potentially be explained by a higher relative importance of stochastic processes under low habitat quality. We also partitioned beta diversity into turnover and nestedness components and we found a nested pattern of beta diversity along the environmental gradient, with communities from the lower-quality habitat being nested subsets of communities from the higher-quality habitat. However, this pattern resulted from an increase in microfauna alpha diversity with an increase in habitat quality. By providing insights into microfauna-environment relationships our results contribute to the mechanistic understanding of community dynamics in small freshwater bodies. Here, we highlight the importance of habitat characteristics representing habitat quality in structuring communities, and suggest that this information may help to improve conservation practices of small freshwater ecosystems.

  13. Different in the dark: The effect of habitat characteristics on community composition and beta diversity in bromeliad microfauna

    Science.gov (United States)

    Antiqueira, Pablo A. P.; Neutzling, Alexandre S.; Wolf, Anna M.; Romero, Gustavo Q.; Petermann, Jana S.

    2018-01-01

    The mechanisms which structure communities have been the focus of a large body of research. Here, we address the question if habitat characteristics describing habitat quality may drive changes in community composition and beta diversity of bromeliad-inhabiting microfauna. In our system, changes in canopy cover along an environmental gradient may affect resource availability, disturbance in form of daily water temperature fluctuations and predation, and thus may lead to changes in community structure of bromeliad microfauna through differences in habitat quality along this gradient. Indeed, we observed distinct changes in microfauna community composition along the environmental gradient explained by changes in the extent of daily water temperature fluctuations. We found beta diversity to be higher under low habitat quality (low canopy cover) than under high habitat quality (high canopy cover), which could potentially be explained by a higher relative importance of stochastic processes under low habitat quality. We also partitioned beta diversity into turnover and nestedness components and we found a nested pattern of beta diversity along the environmental gradient, with communities from the lower-quality habitat being nested subsets of communities from the higher-quality habitat. However, this pattern resulted from an increase in microfauna alpha diversity with an increase in habitat quality. By providing insights into microfauna-environment relationships our results contribute to the mechanistic understanding of community dynamics in small freshwater bodies. Here, we highlight the importance of habitat characteristics representing habitat quality in structuring communities, and suggest that this information may help to improve conservation practices of small freshwater ecosystems. PMID:29401522

  14. Racioethnicity, community makeup, and potential employees' reactions to organizational diversity management approaches.

    Science.gov (United States)

    Olsen, Jesse E; Martins, Luis L

    2016-05-01

    We draw on the values literature from social psychology and the acculturation literature from cross-cultural psychology to develop and test a theory of how signals about an organization's diversity management (DM) approach affect perceptions of organizational attractiveness among potential employees. We examine the mediating effects of individuals' merit-based attributions about hiring decisions at the organization, as well as the moderating effects of their racioethnicity and the racioethnic composition of their home communities. We test our theory using a within-subject policy-capturing experimental design that simulates organizational DM approaches, supplemented with census data for the participants' home communities. Results of hierarchical linear modeling (HLM) analyses suggest that the manipulated instrumental value for diversity leads to higher perceptions of organizational attractiveness, in part through heightened expectations of merit-based hiring decisions. Further, the manipulated assimilative and integrative DM approach signals are positively related to organizational attractiveness and the effect of integrative DM is strongest for racioethnic minorities from communities with especially high proportions of Whites and Whites from communities with especially low proportions of Whites. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Functional diversity of benthic ciliate communities in response to environmental gradients in a wetland of Yangtze Estuary, China.

    Science.gov (United States)

    Xu, Yuan; Fan, Xinpeng; Warren, Alan; Zhang, Liquan; Xu, Henglong

    2018-02-01

    Researches on the functional diversity of benthic ecosystems have mainly focused on macrofauna, and studies on functional structure of ciliate communities have been based only on trophic- or size-groups. Current research was carried out on the changing patterns of classical and functional diversity of benthic ciliates in response to environmental gradients at three sites in a wetland in Yangtze Estuary. The results showed that changes of environmental factors (e.g. salinity, sediment grain size and hydrodynamic conditions) in the Yangtze Estuary induce variability in species composition and functional trait distribution. Furthermore, increased species richness and diversity did not lead to significant changes in functional diversity due to functional redundancy. However, salt water intrusion of Yangtze Estuary during the dry season could cause reduced functional diversity of ciliate communities. Current study provides the first insight into the functional diversity of ciliate communities in response to environmental gradients. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Multiuser switched scheduling systems with per-user threshold and post-user selection

    KAUST Repository

    Nam, Haewoon

    2010-06-01

    A multiuser switched diversity scheduling scheme with per-user feedback threshold is proposed in this paper. Unlike the conventional multiuser switched diversity scheduling scheme where a single threshold is used by all the users in order to determine whether to transmit a feedback, the proposed scheme deploys per-user threshold, where each user uses a potentially different threshold than other users thresholds. This paper first provides a generic analytical framework for the optimal feedback thresholds in a closed form. Then we investigates the impact of user sequence strategies and post selection strategies on the performance of the multiuser switched scheduling scheme with per-user threshold. Numerical and simulation results show that the proposed scheme provides a higher system capacity compared to the conventional scheme. © 2010 IEEE.

  17. Multiuser switched scheduling systems with per-user threshold and post-user selection

    KAUST Repository

    Nam, Haewoon; Alouini, Mohamed-Slim

    2010-01-01

    A multiuser switched diversity scheduling scheme with per-user feedback threshold is proposed in this paper. Unlike the conventional multiuser switched diversity scheduling scheme where a single threshold is used by all the users in order to determine whether to transmit a feedback, the proposed scheme deploys per-user threshold, where each user uses a potentially different threshold than other users thresholds. This paper first provides a generic analytical framework for the optimal feedback thresholds in a closed form. Then we investigates the impact of user sequence strategies and post selection strategies on the performance of the multiuser switched scheduling scheme with per-user threshold. Numerical and simulation results show that the proposed scheme provides a higher system capacity compared to the conventional scheme. © 2010 IEEE.

  18. Does social climate influence positive eWOM? A study of heavy-users of online communities.

    Directory of Open Access Journals (Sweden)

    Carla Ruiz-Mafe

    2018-01-01

    Full Text Available This paper provides a deeper understanding of the role of social influences on positive eWOM behaviour (PeWOM of heavy-users of online communities. Drawing on Social Interaction Utility Framework, Group Marketing and Social Learning Theories, we develop and test a research model integrating the interactions between the social climate of a website and Interpersonal Influences in PeWOM. 262 Spanish heavy-users of online communities were selected and the data analysed using partial least squares equation modelling. Overall, the model explains 59% of the variance of PeWOM on online communities. Findings reveal that interaction with other members of the online community (Social Presence is the main predictor of PeWOM. Social Identity is a mediator between Social Presence and PeWOM. Interpersonal Influence has an important role as a moderator variable; the greater the impact of Interpersonal Influence, the stronger the relationship between Social Presence and PeWOM.

  19. Cultural safety, diversity and the servicer user and carer movement in mental health research.

    Science.gov (United States)

    Cox, Leonie G; Simpson, Alan

    2015-12-01

    This study will be of interest to anyone concerned with a critical appraisal of mental health service users' and carers' participation in research collaboration and with the potential of the postcolonial paradigm of cultural safety to contribute to the service user research (SUR) movement. The history and nature of the mental health field and its relationship to colonial processes provokes a consideration of whether cultural safety could focus attention on diversity, power imbalance, cultural dominance and structural inequality, identified as barriers and tensions in SUR. We consider these issues in the context of state-driven approaches towards SUR in planning and evaluation and the concurrent rise of the SUR movement in the UK and Australia, societies with an intimate involvement in processes of colonisation. We consider the principles and motivations underlying cultural safety and SUR in the context of the policy agenda informing SUR. We conclude that while both cultural safety and SUR are underpinned by social constructionism constituting similarities in principles and intent, cultural safety has additional dimensions. Hence, we call on researchers to use the explicitly political and self-reflective process of cultural safety to think about and address issues of diversity, power and social justice in research collaboration. © 2015 John Wiley & Sons Ltd.

  20. Long-term effects of plant diversity and composition on soil nematode communities in grassland.

    NARCIS (Netherlands)

    Viketoft, M.; Bengtsson, J.; Sohlenius, B.; Berg, M.P.; Petchey, O.; Palmborg, C.; Huss-Daniel, K.

    2009-01-01

    An important component of plant-soil feedbacks is how plant species identity and diversity influence soil organism communities. We examine the effects of grassland plant species growing alone and together up to a richness of 12 species on nematode diversity and feeding group composition, eight years

  1. National Synchrotron Light Source users manual: Guide to the VUV and x-ray beam lines

    International Nuclear Information System (INIS)

    Gmuer, N.F.; White-DePace, S.M.

    1987-08-01

    The success of the National Synchrotron Light Source in the years to come will be based, in large part, on the size of the users community and the diversity of the scientific disciplines represented by these users. In order to promote this philosophy, this National Synchrotron Light Source (NSLS) Users Manual: Guide to the VUV and X-Ray Beam Lines, has been published. This manual serves a number of purposes. In an effort to attract new research, it will present to the scientific community-at-large the current and projected architecture and capabilities of the various VUV and x-ray beam lines and storage rings. We anticipate that this publication will be updated periodically in order to keep pace with the constant changes at the NSLS

  2. Topicality and impact in social media: diverse messages, focused messengers.

    Science.gov (United States)

    Weng, Lilian; Menczer, Filippo

    2015-01-01

    We have a limited understanding of the factors that make people influential and topics popular in social media. Are users who comment on a variety of matters more likely to achieve high influence than those who stay focused? Do general subjects tend to be more popular than specific ones? Questions like these demand a way to detect the topics hidden behind messages associated with an individual or a keyword, and a gauge of similarity among these topics. Here we develop such an approach to identify clusters of similar hashtags in Twitter by detecting communities in the hashtag co-occurrence network. Then the topical diversity of a user's interests is quantified by the entropy of her hashtags across different topic clusters. A similar measure is applied to hashtags, based on co-occurring tags. We find that high topical diversity of early adopters or co-occurring tags implies high future popularity of hashtags. In contrast, low diversity helps an individual accumulate social influence. In short, diverse messages and focused messengers are more likely to gain impact.

  3. Lack of congruence in species diversity indices and community structures of planktonic groups based on local environmental factors.

    Science.gov (United States)

    Doi, Hideyuki; Chang, Kwang-Hyeon; Nishibe, Yuichiro; Imai, Hiroyuki; Nakano, Shin-ichi

    2013-01-01

    The importance of analyzing the determinants of biodiversity and community composition by using multiple trophic levels is well recognized; however, relevant data are lacking. In the present study, we investigated variations in species diversity indices and community structures of the plankton taxonomic groups-zooplankton, rotifers, ciliates, and phytoplankton-under a range of local environmental factors in pond ecosystems. For each planktonic group, we estimated the species diversity index by using linear models and analyzed the community structure by using canonical correspondence analysis. We showed that the species diversity indices and community structures varied among the planktonic groups and according to local environmental factors. The observed lack of congruence among the planktonic groups may have been caused by niche competition between groups with similar trophic guilds or by weak trophic interactions. Our findings highlight the difficulty of predicting total biodiversity within a system, based upon a single taxonomic group. Thus, to conserve the biodiversity of an ecosystem, it is crucial to consider variations in species diversity indices and community structures of different taxonomic groups, under a range of local conditions.

  4. Assessing group differences in biodiversity by simultaneously testing a user-defined selection of diversity indices.

    Science.gov (United States)

    Pallmann, Philip; Schaarschmidt, Frank; Hothorn, Ludwig A; Fischer, Christiane; Nacke, Heiko; Priesnitz, Kai U; Schork, Nicholas J

    2012-11-01

    Comparing diversities between groups is a task biologists are frequently faced with, for example in ecological field trials or when dealing with metagenomics data. However, researchers often waver about which measure of diversity to choose as there is a multitude of approaches available. As Jost (2008, Molecular Ecology, 17, 4015) has pointed out, widely used measures such as the Shannon or Simpson index have undesirable properties which make them hard to compare and interpret. Many of the problems associated with the use of these 'raw' indices can be corrected by transforming them into 'true' diversity measures. We introduce a technique that allows the comparison of two or more groups of observations and simultaneously tests a user-defined selection of a number of 'true' diversity measures. This procedure yields multiplicity-adjusted P-values according to the method of Westfall and Young (1993, Resampling-Based Multiple Testing: Examples and Methods for p-Value Adjustment, 49, 941), which ensures that the rate of false positives (type I error) does not rise when the number of groups and/or diversity indices is extended. Software is available in the R package 'simboot'. © 2012 Blackwell Publishing Ltd.

  5. Exploring the role of intermediary organizations in firm and user community collaborations: Resolving or multiplying paradoxes?

    DEFF Research Database (Denmark)

    Dragsdahl Lauritzen, Ghita

    2015-01-01

    Research on user innovation shows that innovation can be impeded by the conflicting demands that arise in the context of collaborations between firms and their user communities. One stream of research, however, applies a paradox lens to argue that intermediary organizations can help to resolve...... these conflicts, by bridging the opposing logics in which they originate. On the basis of an embedded case study, this article suggests that instead of resolving a paradox of innovation, intermediaries create new paradoxical tensions. Further, I argue that mediating firm-community collaboration is not a matter...

  6. Multi-scale functional and taxonomic β-diversity of the macroinvertebrate communities in a Mediterranean coastal lagoon

    Directory of Open Access Journals (Sweden)

    D. CABANA

    2017-03-01

    Full Text Available Benthic macroinvertebrate communities form the basis of the intricate lagoonal food web. Understanding their functional and taxonomic response, from a β-diversity perspective, is essential to disclose underlying patterns with potential applicability in conservation and management actions. Within the central lagoon of Messolonghi we studied the main environmental components structuring the macroinvertebrate community. We analyzed the β-taxonomic and β-functional diversity across the main habitats and seasons, over a year time frame. Our results outline habitat type and vegetation biomass as the major factors structuring the communities. We found environmental variability to have a positive correlation with functional β-diversity, however no correlation was found with taxonomic β-diversity. Across the seasons an asynchronous response of the functional and taxonomic β-diversity was identified. The taxonomic composition displayed significant heterogeneity during the driest period and the functional during the rainy season. Across the habitats the unvegetated presented higher taxonomic homogeneity and functionally heterogeneity, contrary the vegetated habitats present higher taxonomic variability and functional homogeneity. Across the seasons and habitats a pattern of functional redundancy and taxonomic replacement was identified. Besides high functional turnover versus low taxonomic turnover was documented in an anthropogenic organically enriched habitat We conclude that habitats display independent functional and taxonomic seasonal patterns, thus different processes may contribute to their variability. The framework presented here highlights the importance of studying both β-diversity components framed in a multiscale approach to better understand ecological processes and variability patterns. These results are important to understand macroinvertebrate community assembly processes and are valuable for conservation purposes.

  7. Enlisting User Community Perspectives to Inform Development of a Semantic Web Application for Discovery of Cross-Institutional Research Information and Data

    Science.gov (United States)

    Johns, E. M.; Mayernik, M. S.; Boler, F. M.; Corson-Rikert, J.; Daniels, M. D.; Gross, M. B.; Khan, H.; Maull, K. E.; Rowan, L. R.; Stott, D.; Williams, S.; Krafft, D. B.

    2015-12-01

    Researchers seek information and data through a variety of avenues: published literature, search engines, repositories, colleagues, etc. In order to build a web application that leverages linked open data to enable multiple paths for information discovery, the EarthCollab project has surveyed two geoscience user communities to consider how researchers find and share scholarly output. EarthCollab, a cross-institutional, EarthCube funded project partnering UCAR, Cornell University, and UNAVCO, is employing the open-source semantic web software, VIVO, as the underlying technology to connect the people and resources of virtual research communities. This study will present an analysis of survey responses from members of the two case study communities: (1) the Bering Sea Project, an interdisciplinary field program whose data archive is hosted by NCAR's Earth Observing Laboratory (EOL), and (2) UNAVCO, a geodetic facility and consortium that supports diverse research projects informed by geodesy. The survey results illustrate the types of research products that respondents indicate should be discoverable within a digital platform and the current methods used to find publications, data, personnel, tools, and instrumentation. The responses showed that scientists rely heavily on general purpose search engines, such as Google, to find information, but that data center websites and the published literature were also critical sources for finding collaborators, data, and research tools.The survey participants also identify additional features of interest for an information platform such as search engine indexing, connection to institutional web pages, generation of bibliographies and CVs, and outward linking to social media. Through the survey, the user communities prioritized the type of information that is most important to display and describe their work within a research profile. The analysis of this survey will inform our further development of a platform that will

  8. National Synchrotron Light Source user's manual: Guide to the VUV and x-ray beamlines

    International Nuclear Information System (INIS)

    Gmuer, N.F.

    1993-04-01

    The success of the National Synchrotron Light Source is based, in large part, on the size of the user community and the diversity of the scientific and technical disciplines represented by these users. As evidence of this success, the VUV Ring has just celebrated its 10th anniversary and the X-ray Ring will do the same in 1995. In order to enhance this success, the NSLS User's Manual: Guide to the VUV and X-Ray Beamlines - Fifth Edition, is being published. This Manual presents to the scientific community-at-large the current and projected architecture, capabilities and research programs of the various VUV and X-ray beamlines. Also detailed is the research and computer equipment a General User can expect to find and use at each beamline when working at the NSLS. The Manual is updated periodically in order to keep pace with the constant changes on these beamlines

  9. Plant diversity and plant identity influence Fusarium communities in soil.

    Science.gov (United States)

    LeBlanc, Nicholas; Kinkel, Linda; Kistler, H Corby

    2017-01-01

    Fusarium communities play important functional roles in soil and in plants as pathogens, endophytes, and saprotrophs. This study tests how rhizosphere Fusarium communities may vary with plant species, changes in the diversity of the surrounding plant community, and soil physiochemical characteristics. Fusarium communities in soil associated with the roots of two perennial prairie plant species maintained as monocultures or growing within polyculture plant communities were characterized using targeted metagenomics. Amplicon libraries targeting the RPB2 locus were generated from rhizosphere soil DNAs and sequenced using pyrosequencing. Sequences were clustered into operational taxonomic units (OTUs) and assigned a taxonomy using the Evolutionary Placement Algorithm. Fusarium community composition was differentiated between monoculture and polyculture plant communities, and by plant species in monoculture, but not in polyculture. Taxonomic classification of the Fusarium OTUs showed a predominance of F. tricinctum and F. oxysporum as well of the presence of a clade previously only found in the Southern Hemisphere. Total Fusarium richness was not affected by changes in plant community richness or correlated with soil physiochemical characteristics. However, OTU richness within two predominant phylogenetic lineages within the genus was positively or negatively correlated with soil physiochemical characteristics among samples within each lineage. This work shows that plant species, plant community richness, and soil physiochemical characteristics may all influence the composition and richness of Fusarium communities in soil.

  10. Phylogenetic and Functional Diversity of Total (DNA) and Expressed (RNA) Bacterial Communities in Urban Green Infrastructure Bioswale Soils.

    Science.gov (United States)

    Gill, Aman S; Lee, Angela; McGuire, Krista L

    2017-08-15

    New York City (NYC) is pioneering green infrastructure with the use of bioswales and other engineered soil-based habitats to provide stormwater infiltration and other ecosystem functions. In addition to avoiding the environmental and financial costs of expanding traditional built infrastructure, green infrastructure is thought to generate cobenefits in the form of diverse ecological processes performed by its plant and microbial communities. Yet, although plant communities in these habitats are closely managed, we lack basic knowledge about how engineered ecosystems impact the distribution and functioning of soil bacteria. We sequenced amplicons of the 16S ribosomal subunit, as well as seven genes associated with functional pathways, generated from both total (DNA-based) and expressed (RNA) soil communities in the Bronx, NYC, NY, in order to test whether bioswale soils host characteristic bacterial communities with evidence for enriched microbial functioning, compared to nonengineered soils in park lawns and tree pits. Bioswales had distinct, phylogenetically diverse bacterial communities, including taxa associated with nutrient cycling and metabolism of hydrocarbons and other pollutants. Bioswale soils also had a significantly greater diversity of genes involved in several functional pathways, including carbon fixation ( cbbL-R [ cbbL gene, red-like subunit] and apsA ), nitrogen cycling ( noxZ and amoA ), and contaminant degradation ( bphA ); conversely, no functional genes were significantly more abundant in nonengineered soils. These results provide preliminary evidence that urban land management can shape the diversity and activity of soil communities, with positive consequences for genetic resources underlying valuable ecological functions, including biogeochemical cycling and degradation of common urban pollutants. IMPORTANCE Management of urban soil biodiversity by favoring taxa associated with decontamination or other microbial metabolic processes is a

  11. Using a social marketing framework to evaluate recruitment of a prospective study of genetic counseling and testing for the deaf community.

    Science.gov (United States)

    Kobayashi, Yoko; Boudreault, Patrick; Hill, Karin; Sinsheimer, Janet S; Palmer, Christina G S

    2013-11-25

    Recruiting deaf and hard-of-hearing participants, particularly sign language-users, for genetics health service research is challenging due to communication barriers, mistrust toward genetics, and researchers' unfamiliarity with deaf people. Feelings of social exclusion and lack of social cohesion between researchers and the Deaf community are factors to consider. Social marketing is effective for recruiting hard-to-reach populations because it fosters social inclusion and cohesion by focusing on the targeted audience's needs. For the deaf population this includes recognizing their cultural and linguistic diversity, their geography, and their systems for information exchange. Here we use concepts and language from social marketing to evaluate our effectiveness to engage a U.S. deaf population in a prospective, longitudinal genetic counseling and testing study. The study design was interpreted in terms of a social marketing mix of Product, Price, Place, and Promotion. Price addressed linguistic diversity by including a variety of communication technologies and certified interpreters to facilitate communication; Place addressed geography by including community-based participation locations; Promotion addressed information exchange by using multiple recruitment strategies. Regression analyses examined the study design's effectiveness in recruiting a culturally and linguistically diverse sample. 271 individuals were enrolled, with 66.1% American Sign Language (ASL)-users, 19.9% ASL + English-users, 12.6% English-users. Language was significantly associated with communication technology, participation location, and recruitment. Videophone and interpreters were more likely to be used for communication between ASL-users and researchers while voice telephone and no interpreters were preferred by English-users (Price). ASL-users were more likely to participate in community-based locations while English-users preferred medically-based locations (Place). English-users were

  12. Designing 3ERP to meet use and users - methods to handle cultural diversity and collaborative networking in SMEs

    DEFF Research Database (Denmark)

    Dirckinck-Holmfeld, Lone; Nielsen, Janni

    2007-01-01

    The purpose is to describe a project the aim of which is to develop and validate the scientific methodological foundation for design of user friendly and usable, flexible and configurable global Enterprise Resource Planning system for Small and Medium sized Enterprises (SMEs) which are adoptable ...... to cultural diversity and support the collaborative networking tasks embedded in 3gERP. Focus is on Human Centered Design methods and tools which must be developed to handle cultural diversity....

  13. From Help-Seekers to Influential Users: A Systematic Review of Participation Styles in Online Health Communities.

    Science.gov (United States)

    Carron-Arthur, Bradley; Ali, Kathina; Cunningham, John Alastair; Griffiths, Kathleen Margaret

    2015-12-01

    Understanding how people participate in and contribute to online health communities (OHCs) is useful knowledge in multiple domains. It is helpful for community managers in developing strategies for building community, for organizations in disseminating information about health interventions, and for researchers in understanding the social dynamics of peer support. We sought to determine if any patterns were apparent in the nature of user participation across online health communities. The current study involved a systematic review of all studies that have investigated the nature of participation in an online health community and have provided a quantifiable method for categorizing a person based on their participation style. A systematic search yielded 20 papers. Participatory styles were classified as either multidimensional (based on multiple metrics) or unidimensional (based on one metric). With respect to the multidimensional category, a total of 41 different participation styles were identified ranging from Influential Users who were leaders on the board to Topic-Focused Responders who focused on a specific topic and tended to respond to rather than initiate posts. However, there was little overlap in participation styles identified both across OHCs for different health conditions and within OHCs for specific health conditions. Five of the 41 styles emerged in more than one study (Hubs, Authorities, Facilitators, Prime Givers, and Discussants), but the remainder were reported in only one study. The focus of the unidimensional studies was on level of engagement and particularly on high-engaged users. Eight different metrics were used to evaluate level of engagement with the greatest focus on frequency of posts. With the exception of high-engaged users based on high post frequency, the current review found little evidence for consistent participatory styles across different health communities. However, this area of research is in its infancy, with most of the

  14. Diversity and Spatial-Temporal Distribution of Soil Macrofauna Communities Along Elevation in the Changbai Mountain, China.

    Science.gov (United States)

    Yin, Xiuqin; Qiu, Lili; Jiang, Yunfeng; Wang, Yeqiao

    2017-06-01

    The understanding of patterns of vertical variation and diversity of flora and fauna along elevational change has been well established over the past century. However, it is unclear whether there is an elevational distribution pattern for soil fauna. This study revealed the diversity and spatial-temporal distribution of soil macrofauna communities in different vegetation zones from forest to alpine tundra along elevation of the Changbai Mountain, China. The abundance, richness, and Shannon-Wiener diversity index of soil macrofauna communities were compared in four distinguished vegetation zones including the coniferous and broadleaved mixed forest zone, the coniferous forest zone, the subalpine dwarf birch (Betula ermanii) forest zone, and the alpine tundra zone. Soil macrofauna were extracted in May, July, and September of 2009. In each season, the abundance and richness of the soil macrofauna decreased with the ascending elevation. The Shannon-Wiener diversity indices of the soil macrofauna were higher in the vegetation zones of lower elevation than of higher elevation. Significant differences were observed in the abundance, richness, and Shannon-Wiener diversity index for the studied vegetation zones. Soil macrofauna congregated mainly to the litter layer in the low-elevation areas and in the 0-5 cm soil layer of the higher elevation areas. The results emphasized that the diversity of soil macrofauna communities decreased as the elevation increased and possess the distinct characteristics of zonation in the mountain ecosystem. The diversity and distribution of soil macrofauna communities were influenced by mean annual precipitation, altitude, annual radiation quantity, and mean annual temperature. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Structure and phylogenetic diversity of post-fire ectomycorrhizal communities of maritime pine.

    Science.gov (United States)

    Rincón, A; Santamaría, B P; Ocaña, L; Verdú, M

    2014-02-01

    Environmental disturbances define the diversity and assemblage of species, affecting the functioning of ecosystems. Fire is a major disturbance of Mediterranean pine forests. Pines are highly dependent on the ectomycorrhizal (EM) fungal symbiosis, which is critical for tree recruitment under primary succession. To determine the effects of time since fire on the structure and recovery of EM fungal communities, we surveyed the young Pinus pinaster regenerate in three sites differing in the elapsed time after the last fire event. Pine roots were collected, and EM fungi characterized by sequencing the internal transcribed spacer (ITS) and the large subunit (LSU) regions of the nuclear ribosomal (nr)-DNA. The effects of the elapsed time after fire on the EM community structure (richness, presence/absence of fungi, phylogenetic diversity) and on soil properties were analysed.Fungal richness decreased with the elapsed time since the fire; although, the phylogenetic diversity of the EM community increased. Soil properties were different depending on the elapsed time after fire and particularly, the organic matter, carbon-to-nitrogen (C/N) ratio, nitrogen and iron significantly correlated with the assemblage of fungal species. Ascomycetes, particularly Tuberaceae and Pezizales, were significantly over-represented on saplings in the burned site. On seedlings, a significant over-representation of Rhizopogonaceae and Atheliaceae was observed in the most recently burned site, while other fungi (i.e. Cortinariaceae) were significantly under-represented. Our results are consistent with the hypothesis that fire can act as a selective agent by printing a phylogenetic signal on the EM fungal communities associated with naturally regenerated pines, pointing out to some groups as potential fire-adapted fungi.

  16. Perspectives on the Massachusetts Community Health Information Profile (MassCHIP): developing an online data query system to target a variety of user needs and capabilities.

    Science.gov (United States)

    Cohen, Bruce B; Franklin, Saul; West, James K

    2006-01-01

    The Massachusetts Community Health Information Profile (MassCHIP) has many distinctive features. These features evolved to maximize the usefulness of this query system for a broad group of users with varied needs, differing levels of knowledge about public health, and diverse experience using public health data. Three major features of MassCHIP help target our large user population. These features are as follows: (1) multiple avenues of entry to initiate queries ranging from an alphabetical list of simple topics to detailed International Classification of Disease codes; (2) the inclusion of data sets from other state agencies in addition to those of the Massachusetts Department of Public Health to reflect a broad view of public health; and (3) the capacity to retrieve data for multiple levels of geography, from the neighborhood through the state, including planning districts and hospitals. In this article, we discuss the history and design of MassCHIP, and focus on the features of MassCHIP that target a great variety of user needs and capabilities, and which are distinctive among Web-based data query systems.

  17. Modeling the Effects of Trait Diversity on Short-term Adaptive Capacity and Long-term Productivity of Phytoplankton Communities

    Science.gov (United States)

    Smith, S. L.; Vallina, S. M.; Merico, A.

    2016-02-01

    We examine Biodiversity and Ecosystem Function (BEF) in a model phytoplankton community, using two recently developed mechanisms for sustaining diversity. The Trait Diffusion (TD) formulation represents the maintenance of diversity via endogenous mechanisms, such as inter-generational trait plasticity and rapid evolution. The 'Kill-the-Winner' (KTW) formulation for grazing sustains prey biodiversity via the exogenous mechanism of active prey switching. We implement both TD and KTW in a continuous trait-distribution model using simplified size-scalings to define a gleaner-opportunist trade-off for a phytoplankton community. By simulating semi-continuous culture experiments with periodic external dilutions, we test the dynamic response of the phytoplankton community to different scenarios of pulsed nutrient supply. We quantify the short-term Adaptive Capacity (AC) of the community by the specific growth rate averaged over the first 3 days of perturbations, and the Long-term Productivity (LP) by its average over the entire 120 day period of perturbations. When either the frequency or intensity of pulses is low, both AC and LP tend to decrease with diversity (and vice versa). Trait diversity has more impact on AC, particularly for pulses of high frequency or intensity, for which it tends to increase gradually at first, then steeply, and then to saturate with increasing diversity. For pulses of moderate intensity and frequency, increasing trait diversity from low to moderate levels leads to a trade-off between enhancing AC while slightly decreasing LP. Ultimately, we find that sustaining diversity increases the speed at which the phytoplankton community changes its composition in terms of size and hence nutrient acquisition traits, which may have implications for the transfer of productivity through the foodweb.

  18. Impact of metal pollution on fungal diversity and community structures.

    Science.gov (United States)

    Op De Beeck, Michiel; Lievens, Bart; Busschaert, Pieter; Rineau, Francois; Smits, Mark; Vangronsveld, Jaco; Colpaert, Jan V

    2015-06-01

    The impact of metal pollution on plant communities has been studied extensively in the past, but little is known about the effects of metal pollution on fungal communities that occur in metal-polluted soils. Metal-tolerant ecotypes of the ectomycorrhizal fungus Suillus luteus are frequently found in pioneer pine forests in the Campine region in Belgium on metal-polluted soils. We hypothesized that metal pollution would play an important role in shaping below-ground fungal communities that occur in these soils and that Suillus luteus would be a dominant player. To test these hypotheses, the fungal communities in a young pine plantation in soil polluted with zinc, and cadmium were studied using 454 amplicon pyrosequencing. Results show that zinc, cadmium and soil organic matter content were strongly correlated with the fungal community composition, but no effects on fungal diversity were observed. As hypothesized, S. luteus was found to be a dominant member of the studied fungal communities. However, other dominant fungal species, such as Sistotrema sp., Wilcoxina mikolae and Cadophora finlandica were found as well. Their presence in metal-polluted sites is discussed. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. User-centered design with illiterate persons : The case of the ATM user interface

    NARCIS (Netherlands)

    Cremers, A.H.M.; Jong, J.G.M. de; Balken, J.S. van

    2008-01-01

    One of the major challenges in current user interface research and development is the accommodation of diversity in users and contexts of use in order to improve the self-efficacy of citizens. A common banking service, which should be designed for diversity, is the Automated Teller Machine (ATM).

  20. Major changes in microbial diversity and community composition across gut sections of a juvenile Panchlora cockroach.

    Directory of Open Access Journals (Sweden)

    Erin A Gontang

    Full Text Available Investigations of gut microbiomes have shed light on the diversity and genetic content of these communities, and helped shape our understanding of how host-associated microorganisms influence host physiology, behavior, and health. Despite the importance of gut microbes to metazoans, our understanding of the changes in diversity and composition across the alimentary tract, and the source of the resident community are limited. Here, using community metagenomics and 16S rRNA gene sequencing, we assess microbial community diversity and coding potential in the foregut, midgut, and hindgut of a juvenile Panchlora cockroach, which resides in the refuse piles of the leaf-cutter ant species Atta colombica. We found a significant shift in the microbial community structure and coding potential throughout the three gut sections of Panchlora sp., and through comparison with previously generated metagenomes of the cockroach's food source and niche, we reveal that this shift in microbial community composition is influenced by the ecosystems in which Panchlora sp. occurs. While the foregut is composed of microbes that likely originate from the symbiotic fungus gardens of the ants, the midgut and hindgut are composed of a microbial community that is likely cockroach-specific. Analogous to mammalian systems, the midgut and hindgut appear to be dominated by Firmicutes and Bacteroidetes with the capacity for polysaccharide degradation, suggesting they may assist in the degradation of dietary plant material. Our work underscores the prominence of community changes throughout gut microbiomes and highlights ecological factors that underpin the structure and function of the symbiotic microbial communities of metazoans.

  1. Major changes in microbial diversity and community composition across gut sections of a juvenile Panchlora cockroach.

    Science.gov (United States)

    Gontang, Erin A; Aylward, Frank O; Carlos, Camila; Glavina Del Rio, Tijana; Chovatia, Mansi; Fern, Alison; Lo, Chien-Chi; Malfatti, Stephanie A; Tringe, Susannah G; Currie, Cameron R; Kolter, Roberto

    2017-01-01

    Investigations of gut microbiomes have shed light on the diversity and genetic content of these communities, and helped shape our understanding of how host-associated microorganisms influence host physiology, behavior, and health. Despite the importance of gut microbes to metazoans, our understanding of the changes in diversity and composition across the alimentary tract, and the source of the resident community are limited. Here, using community metagenomics and 16S rRNA gene sequencing, we assess microbial community diversity and coding potential in the foregut, midgut, and hindgut of a juvenile Panchlora cockroach, which resides in the refuse piles of the leaf-cutter ant species Atta colombica. We found a significant shift in the microbial community structure and coding potential throughout the three gut sections of Panchlora sp., and through comparison with previously generated metagenomes of the cockroach's food source and niche, we reveal that this shift in microbial community composition is influenced by the ecosystems in which Panchlora sp. occurs. While the foregut is composed of microbes that likely originate from the symbiotic fungus gardens of the ants, the midgut and hindgut are composed of a microbial community that is likely cockroach-specific. Analogous to mammalian systems, the midgut and hindgut appear to be dominated by Firmicutes and Bacteroidetes with the capacity for polysaccharide degradation, suggesting they may assist in the degradation of dietary plant material. Our work underscores the prominence of community changes throughout gut microbiomes and highlights ecological factors that underpin the structure and function of the symbiotic microbial communities of metazoans.

  2. Legacy effects of no-analogue disturbances alter plant community diversity and composition in semi-arid sagebrush steppe

    Science.gov (United States)

    Ripplinger, Julie; Franklin, Janet; Edwards, Thomas C.

    2015-01-01

    Questions(i) What role does the type of managed disturbance play in structuring sagebrush steppe plant communities? (ii) How does the composition of post-disturbance plant communities change with time since disturbance? (iii) Does plant community diversity change over time following managed disturbance?LocationField study within the sagebrush steppe ecosystem. Rich County, Utah, USA.MethodsWe developed a chronosequence spanning up to 50 yrs post-treatment to study sagebrush steppe vegetation dynamics. Direct ordination was used to examine plant community composition by managed disturbance type and time since disturbance, and factorial analysis of covariance was used to examine diversity dynamics following disturbance. Indicator species values were calculated in order to identify characteristic species for each disturbance type.ResultsPlant communities experienced a shift toward distinct community composition for each of the three managed disturbance types, and gave no indication of returning to untreated community composition or diversity. Small post-disturbance increases in the number of non-native grass species were observed in the treatments relative to reference, with native forb species making the largest contribution to altered composition. On fire- and chemically-treated sites the proportional native forb species richness increased over time since disturbance, while the proportional contribution of non-native forbs to total species richness decreased. For all three treatment types, native grasses contributed less on average to total richness than on reference sites, while non-native grasses made up a higher proportion of total richness.ConclusionsCommon shrubland management techniques have legacy effects on the composition and diversity of sagebrush steppe plant communities, and no-analogue disturbances, such as chemical or mechanical treatments, have more pronounced legacy effects than treatments similar to natural disturbance regimes (fire). This study

  3. Diversity of MAPs in some plant communities of Stara Planina

    Directory of Open Access Journals (Sweden)

    Obratov-Petković Dragica

    2006-01-01

    Full Text Available The high floristic diversity of Stara Planina was the starting base for the research of medicinal and aromatic plants (MAPs in individual forest and meadow communities. The sites Javor and Prelesje, forest community Fagetum moesiacae montanum B. Jov. 1953, pioneer community of birch Betuletum verrucosae s.l. and meadow community Agrostietum vulgaris (capillaris Pavlović, Z. 1955, were researched as follows: soil types, floristic composition and structure of the community, percentage of MAPs, as well as the selection of species which, according to the predetermined criteria can be recommended for further exploitation. The study shows that the soil of the forest communities is eutric brown, and meadow soils are dystric and eutric humus-siliceous. The percentage of MAPs in the floristic structure of the study sites in forest and meadow communities is 32.35%. The following species can be recommended for the collection and utilisation: Hypericum perforatum L., Asperula odorata L., Dryopteris filix-mas (L Schott. Urtica dioica L., Euphorbia amygdaloides L., Prunella grandiflora L. Tanacetum vulgare L., Achillea millefolium L., Rumex acetosa L., Campanula glomerata L., Stachys officinalis (L Trevis., Plantago lanceolata W. et K., Potentilla erecta (L Rauchel, Chamaespartium sagittale (L P. Gibbs. Cynanchum vincetoxicum (L Pers., Euphrasia stricta Host., Fagus moesiaca (Matt Liebl. and Fragaria vesca L.

  4. Soil microbial community profiles and functional diversity in limestone cedar glades

    Science.gov (United States)

    Cartwright, Jennifer M.; Dzantor, E. Kudjo; Momen, Bahram

    2016-01-01

    Rock outcrop ecosystems, such as limestone cedar glades (LCGs), are known for their rare and endemic plant species adapted to high levels of abiotic stress. Soils in LCGs are thin (< 25 cm), soil-moisture conditions fluctuate seasonally between xeric and saturated, and summer soil temperatures commonly exceed 48 °C. The effects of these stressors on soil microbial communities (SMC) remain largely unstudied, despite the importance of SMC-plant interactions in regulating the structure and function of terrestrial ecosystems. SMC profiles and functional diversity were characterized in LCGs using community level physiological profiling (CLPP) and plate-dilution frequency assays (PDFA). Most-probable number (MPN) estimates and microbial substrate-utilization diversity (H) were positively related to soil thickness, soil organic matter (OM), soil water content, and vegetation density, and were diminished in alkaline soil relative to circumneutral soil. Soil nitrate showed no relationship to SMCs, suggesting lack of N-limitation. Canonical correlation analysis indicated strong correlations between microbial CLPP patterns and several physical and chemical properties of soil, primarily temperature at the ground surface and at 4-cm depth, and secondarily soil-water content, enabling differentiation by season. Thus, it was demonstrated that several well-described abiotic determinants of plant community structure in this ecosystem are also reflected in SMC profiles.

  5. Reasons for the treatment of users of crack in a therapeutic community

    Directory of Open Access Journals (Sweden)

    Maycon Rogério Seleghim

    2015-07-01

    Full Text Available Objective: Knowing the motivation of crack users for treatment in hospital environments. Method: Descriptive and qualitative search, using the design of some cases. Twenty male crack users, aged over 18 years old, hospitalized in a Therapeutic Community in Southern Brazil, were interviewed. A semi-structured interview was used and the data were analyzed by their thematic content. Results: Were found three categories that reflect the treatment motivations: perception of the crack harmful consequences; the compulsive use of drugs as the treatment initiation; and, the family participation looking for a treatment. Conclusion: Significant events (turning points favored the interruption of the crack use and the family assumed a very important place to the users behavior in relation to the use of the drug, exclusively. Descriptors: Street drugs, Crack Cocaine, Substance Abuse Treatment Centers, Family.

  6. Disseminating online tools for building capacity among community practitioners.

    Science.gov (United States)

    Holt, Christina M; Fawcett, Stephen B; Schultz, Jerry A; Jones, Jami A; Berkowitz, Bill; Wolff, Thomas J; Francisco, Vincent T; Rabinowitz, Philip W

    2013-01-01

    To prepare the workforce for building healthier communities, we need to assure capabilities of a diverse and geographically distributed community of practitioners. Although the Internet is used extensively to disseminate practice information, less is known about the relative impact of various strategies for promoting its use. This empirical case study examines implementation of dissemination strategies and their association with increased user sessions in the online Community Tool Box (CTB), a widely used resource for community building. Dissemination activities included social media efforts, eNewsletters, search engine optimization efforts, partnering with other Web sites, and implementing a global Out of the Box Prize. Results suggest that increased user sessions were associated with search optimization and "mashups" delivering CTB content through partners' Web sites. The report concludes with a discussion of challenges and opportunities in promoting widespread use of capacity-building tools among those working to improve their communities.

  7. Maximising the benefits of satellite LST within the user community: ESA DUE GlobTemperature

    Science.gov (United States)

    Ghent, D.

    2014-12-01

    Land surface temperature (LST) is the mean radiative skin temperature of an area of land resulting from the mean balance of solar heating and land-atmosphere cooling fluxes. It is a basic determinant of the terrestrial thermal behaviour, as it controls the effective radiating temperature of the Earth's surface. The sensitivity of LST to soil moisture and vegetation cover means it is an important component in numerous applications. With the demand for LST data from Earth Observation currently experiencing considerable growth it is important that the users of this data are appropriately engaged by the LST data providers. The GlobTemperature project under the Data User Element of ESA's 4th Earth Observation Envelope Programme (2013-2017) aims to promote the wider uptake of global-scale satellite LST by the research and operational user communities; the key to success depending on the coherence and openness of the interactions between the LST and user communities. By incorporating detailed user input into the specifications, their subsequent testing of the LST data sets, and sustained access to data in a user-friendly manner through common data formats GlobTemperature is enhancing the portfolio of LST products from Earth Observation, while concurrently breaking down the barriers to successful application of such data through its programme of dialogue between the data providers and data users. Here we present the outcomes from the first phase of the project, which is achieving some innovative developments: a globally representative and consistent matchup database enabling validation and intercomparison of multi-sensor LST data sets; a prototype combined geostationary earth orbit (GEO) and low earth orbit (LEO) global data set for LST to resolve the diurnal cycle which is a key request from users of LST data; the delivery of the first LST data sets via a dedicated Data Portal in harmonised data format; and the establishment, in collaboration with international colleagues

  8. Effects of diversity and identity of the neighbouring plant community on the abundance of arthropods on individual ragwort (Jacobaea vulgaris) plants

    NARCIS (Netherlands)

    Kostenko, O.; Grootemaat, Saskia S.; Van der Putten, W.H.; Bezemer, T.M.

    2012-01-01

    The diversity of plant community can greatly affect the abundance and diversity of arthropods associated to that community, but can also influence the composition or abundance of arthropods on individual plants growing in that community. We sampled arthropods and recorded plant size of individual

  9. Chronic polyaromatic hydrocarbon (PAH contamination is a marginal driver for community diversity and prokaryotic predicted functioning in coastal sediments

    Directory of Open Access Journals (Sweden)

    Mathilde Jeanbille

    2016-08-01

    Full Text Available Benthic microorganisms are key players in the recycling of organic matter and recalcitrant compounds such as polyaromatic hydrocarbons (PAHs in coastal sediments. Despite their ecological importance, the response of microbial communities to chronic PAH pollution, one of the major threats to coastal ecosystems, has received very little attention. In one of the largest surveys performed so far on coastal sediments, the diversity and composition of microbial communities inhabiting both chronically contaminated and non-contaminated coastal sediments were investigated using high-throughput sequencing on the 18S and 16S rRNA genes. Prokaryotic alpha-diversity showed significant association with salinity, temperature, and organic carbon content. The effect of particle size distribution was strong on eukaryotic diversity. Similarly to alpha-diversity, beta-diversity patterns were strongly influenced by the environmental filter, while PAHs had no influence on the prokaryotic community structure and a weak impact on the eukaryotic community structure at the continental scale. However, at the regional scale, PAHs became the main driver shaping the structure of bacterial and eukaryotic communities. These patterns were not found for PICRUSt predicted prokaryotic functions, thus indicating some degree of functional redundancy. Eukaryotes presented a greater potential for their use as PAH contamination biomarkers, owing to their stronger response at both regional and continental scales.

  10. ECHO Responds to NASA's Earth Science User Community

    Science.gov (United States)

    Pfister, Robin; Ullman, Richard; Wichmann, Keith; Perkins, Dorothy C. (Technical Monitor)

    2001-01-01

    Over the past decade NASA has designed, built, evolved, and operated the Earth Observing System Data and Information System (EOSDIS) Information Management System (IMS) in order to provide user access to NASA's Earth Science data holdings. During this time revolutionary advances in technology have driven changes in NASA's approach to providing an IMS service. This paper will describe NASA's strategic planning and approach to build and evolve the EOSDIS IMS and to serve the evolving needs of NASA's Earth Science community. It discusses the original strategic plan and how lessons learned help to form a new plan, a new approach and a new system. It discusses the original technologies and how they have evolved to today.

  11. Interspecific competition influences the organization of a diverse sessile insect community

    Science.gov (United States)

    Cornelissen, Tatiana; de Carvalho Guimarães, Carla Daniele; Rodrigues Viana, João Paulo; Silva, Bárbara

    2013-10-01

    Interspecific competition has played a major role in determining the effects of species interactions in terrestrial communities and the perception of its role on shaping population dynamics and community structure has changed throughout the years. In this study, we evaluated the existence of interspecific competition in the herbivore community of the dioecious plant Baccharis pseudomyriocephala (Asteraceae), which holds a diverse community of gall-forming insects. Sixty plants were studied and gall richness and abundance among plants were evaluated. To address whether a plant already occupied by a gall species is preferred or avoided by another gall species, null models were used for all 60 plants combined and for male and female plants separately. Our results have shown that the 11 species of gall-formers found on B. pseudomyriocephala co-occur less than expected by chance alone, indicating that interspecific competition might be an important force structuring the insect community in this tropical host plant, regardless of plant gender.

  12. Access to health and human services for drug users: an urban/rural community systems perspective.

    Science.gov (United States)

    Rivers, J E; Komaroff, E; Kibort, A C

    1999-01-01

    Publicly funded drug-user treatment programs in both urban and rural areas are under unprecedented pressure to adapt to multiple perspectives of their mission, reduced governmental funding, diminished entitlement program resources for clients, managed care reforms, and continuing unmet need for services. This article describe an ongoing health services research study that is investigating how these and related health and human service programs currently serve and cross-refer chronic drug users and how they perceive and are reacting to systemic pressures. Interim analysis on intra-agency diversity and managed care perceptions are reported.

  13. Pyrosequencing reveals diverse microbial community associated with the zoanthid Palythoa australiae from the South China Sea.

    Science.gov (United States)

    Sun, Wei; Zhang, Fengli; He, Liming; Li, Zhiyong

    2014-05-01

    Diverse sessile organisms inhabit the coral reef ecosystems, including corals, sponges, and sea anemones. In the past decades, scleractinian corals (Cnidaria, Anthozoa, Scleractinia) and their associated microorganisms have attracted much attention. Zoanthids (Cnidaria, Anthozoa, Zoanthidea) are commonly found in coral reefs. However, little is known about the community structure of zoanthid-associated microbiota. In this study, the microbial community associated with the zoanthid Palythoa australiae in the South China Sea was investigated by 454 pyrosequencing. As a result, 2,353 bacterial, 583 archaeal, and 36 eukaryotic microbial ribotypes were detected, respectively. A total of 22 bacterial phyla (16 formally described phyla and six candidate phyla) were recovered. Proteobacteria was the most abundant group, followed by Chloroflexi and Actinobacteria. High-abundance Rhizobiales and diverse Chloroflexi were observed in the bacterial community. The archaeal population was composed of Crenarchaeota and Euryarchaeota, with Marine Group I as the dominant lineage. In particular, Candidatus Nitrosopumilus dominated the archaeal community. Besides bacteria and archaea, the zoanthid harbored eukaryotic microorganisms including fungi and algae though their diversity was very low. This study provided the first insights into the microbial community associated with P. australiae by 454 pyrosequencing, consequently laid a basis for the understanding of the association of P. australiae-microbes symbioses.

  14. Nearly a decade-long repeatable seasonal diversity patterns of bacterioplankton communities in the eutrophic Lake Donghu (Wuhan, China)

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Qingyun [Environmental Microbiome Research Center and the School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou China; Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Stegen, James C. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA USA; Yu, Yuhe [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Deng, Ye [CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing China; Li, Xinghao [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Wu, Shu [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Dai, Lili [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Zhang, Xiang [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Li, Jinjin [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Wang, Chun [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Ni, Jiajia [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Li, Xuemei [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Hu, Hongjuan [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Xiao, Fanshu [Environmental Microbiome Research Center and the School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou China; Feng, Weisong [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan China; Ning, Daliang [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; He, Zhili [Environmental Microbiome Research Center and the School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou China; Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; Van Nostrand, Joy D. [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; Wu, Liyou [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; Zhou, Jizhong [Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman OK USA; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing China; Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley CA USA

    2017-05-21

    Uncovering which environmental factors have the greatest influence on community diversity patterns and how ecological processes govern community turnover are key questions related to understanding community assembly mechanisms. Although we have good understanding of plant and animal community assembly, the mechanisms regulating diversity patterns of aquatic bacterial communities in lake ecosystems remains poorly understood. Here we present nearly a decade-long time-series study of bacterioplankton communities from the eutrophic Lake Donghu (Wuhan, China) using 16S rRNA gene amplicon sequencing. We found strong repeatable seasonal patterns for the overall community, common (detected in more than 50% samples) and dominant bacterial taxa (relative abundance > 1%). Moreover, community composition tracked the seasonal temperature gradient, indicating that temperature is an important environmental factor controlling observed diversity patterns. Total phosphorus also contributed significantly to the seasonal shifts in bacterioplankton composition. However, any spatial pattern across the main lake areas was overwhelmed by temporal variability in this eutrophic lake system. Phylogenetic analysis further indicated that 75%-82% of community turnover was governed by homogeneous selection, suggesting that the bacterioplankton communities are mainly controlled by niche-based processes. However, dominant niches available within seasons might be occupied by similar combinations of bacterial taxa with modest dispersal rates throughout this lake system. This study gives us important insights into community assembly and seasonal turnover of lake bacterioplankton, it may be also useful to predict temporal patterns of other planktonic communities.

  15. YouPower : An open source platform for community-oriented smart grid user engagement

    NARCIS (Netherlands)

    Huang, Yilin; Hasselqvist, Hanna; Poderi, Giacomo; Scepanovic, S.; Kis, F.; Bogdan, Cristian; Warnier, Martijn; Brazier, F.M.

    2017-01-01

    This paper presents YouPower, an open source platform designed to make people more aware of their energy consumption and encourage sustainable consumption with local communities. The platform is designed iteratively in collaboration with users in the Swedish and Italian test sites of the project

  16. Exploring, exploiting and evolving diversity of aquatic ecosystem models: a community perspective

    NARCIS (Netherlands)

    Janssen, A.B.G.; Gerla, D.J.

    2015-01-01

    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality

  17. Zooplankton standing stock, community structure and diversity in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Srivastava, Y.

    The effects of large scale oil spill, which occurred during the Gulf War in 1991 on zooplankton standing stock, community structure and diversity in the northern Arabian Sea were studied. Surface (1-0 m) and vertical zooplankton hauls (200-0 m, 250...

  18. Study on online community user motif using web usage mining

    Science.gov (United States)

    Alphy, Meera; Sharma, Ajay

    2016-04-01

    The Web usage mining is the application of data mining, which is used to extract useful information from the online community. The World Wide Web contains at least 4.73 billion pages according to Indexed Web and it contains at least 228.52 million pages according Dutch Indexed web on 6th august 2015, Thursday. It’s difficult to get needed data from these billions of web pages in World Wide Web. Here is the importance of web usage mining. Personalizing the search engine helps the web user to identify the most used data in an easy way. It reduces the time consumption; automatic site search and automatic restore the useful sites. This study represents the old techniques to latest techniques used in pattern discovery and analysis in web usage mining from 1996 to 2015. Analyzing user motif helps in the improvement of business, e-commerce, personalisation and improvement of websites.

  19. Building a Generic Virtual Research Environment Framework for Multiple Earth and Space Science Domains and a Diversity of Users.

    Science.gov (United States)

    Wyborn, L. A.; Fraser, R.; Evans, B. J. K.; Friedrich, C.; Klump, J. F.; Lescinsky, D. T.

    2017-12-01

    Virtual Research Environments (VREs) are now part of academic infrastructures. Online research workflows can be orchestrated whereby data can be accessed from multiple external repositories with processing taking place on public or private clouds, and centralised supercomputers using a mixture of user codes, and well-used community software and libraries. VREs enable distributed members of research teams to actively work together to share data, models, tools, software, workflows, best practices, infrastructures, etc. These environments and their components are increasingly able to support the needs of undergraduate teaching. External to the research sector, they can also be reused by citizen scientists, and be repurposed for industry users to help accelerate the diffusion and hence enable the translation of research innovations. The Virtual Geophysics Laboratory (VGL) in Australia was started in 2012, built using a collaboration between CSIRO, the National Computational Infrastructure (NCI) and Geoscience Australia, with support funding from the Australian Government Department of Education. VGL comprises three main modules that provide an interface to enable users to first select their required data; to choose a tool to process that data; and then access compute infrastructure for execution. VGL was initially built to enable a specific set of researchers in government agencies access to specific data sets and a limited number of tools. Over the years it has evolved into a multi-purpose Earth science platform with access to an increased variety of data (e.g., Natural Hazards, Geochemistry), a broader range of software packages, and an increasing diversity of compute infrastructures. This expansion has been possible because of the approach to loosely couple data, tools and compute resources via interfaces that are built on international standards and accessed as network-enabled services wherever possible. Built originally for researchers that were not fussy about

  20. The Brazilian freshwater wetscape: Changes in tree community diversity and composition on climatic and geographic gradients.

    Directory of Open Access Journals (Sweden)

    Florian Wittmann

    Full Text Available Wetlands harbor an important compliment of regional plant diversity, but in many regions data on wetland diversity and composition is still lacking, thus hindering our understanding of the processes that control it. While patterns of broad-scale terrestrial diversity and composition typically correlate with contemporary climate it is not clear to what extent patterns in wetlands are complimentary, or conflicting. To elucidate this, we consolidate data from wetland forest inventories in Brazil and examine patterns of diversity and composition along temperature and rainfall gradients spanning five biomes. We collated 196 floristic inventories covering an area >220 ha and including >260,000 woody individuals. We detected a total of 2,453 tree species, with the Amazon alone accounting for nearly half. Compositional patterns indicated differences in freshwater wetland floras among Brazilian biomes, although biomes with drier, more seasonal climates tended to have a larger proportion of more widely distributed species. Maximal alpha diversity increased with annual temperature, rainfall, and decreasing seasonality, patterns broadly consistent with upland vegetation communities. However, alpha diversity-climate relationships were only revealed at higher diversity values associated with the uppermost quantiles, and in most sites diversity varied irrespective of climate. Likewise, mean biome-level differences in alpha-diversity were unexpectedly modest, even in comparisons of savanna-area wetlands to those of nearby forested regions. We describe attenuated wetland climate-diversity relationships as a shifting balance of local and regional effects on species recruitment. Locally, excessive waterlogging strongly filters species able to colonize from regional pools. On the other hand, increased water availability can accommodate a rich community of drought-sensitive immigrant species that are able to track buffered wetland microclimates. We argue that

  1. PHYLOGENETIC AND FUNCTIONAL DIVERSITY OF SEAGULL AND CANADIAN GEESE FECAL MICROBIAL COMMUNITIES

    Science.gov (United States)

    In spite of increasing public health concerns on the risks associated with swimming in waters contaminated with waterfowl feces, there is little information on the gut microbial communities of aquatic birds. To address the molecular microbial diversity of waterfowl, 16S rDNA and ...

  2. Changes in ground beetle diversity and community composition in age structured forests (Coleoptera, Carabidae

    Directory of Open Access Journals (Sweden)

    Kathryn Riley

    2011-11-01

    Full Text Available We examined diversity, community composition, and wing-state of Carabidae as a function of forest age in Piedmont North Carolina. Carabidae were collected monthly from 396 pitfall traps (12×33 sites from March 2009 through February 2010, representing 5 forest age classes approximately 0, 10, 50, 85, and 150 years old. A total of 2,568 individuals, representing 30 genera and 63 species, were collected. Carabid species diversity, as estimated by six diversity indices, was significantly different between the oldest and youngest forest age classes for four of the six indices. Most carabid species were habitat generalists, occurring in all or most of the forest age classes. Carabid species composition varied across forest age classes. Seventeen carabid species were identified as potential candidates for ecological indicators of forest age. Non-metric multidimensional scaling (NMDS showed separation among forest age classes in terms of carabid beetle community composition. The proportion of individuals capable of flight decreased significantly with forest age.

  3. Welcoming Diversity? Symbolic Boundaries and the Politics of Normativity in Kansas City's LGBTQ Communities.

    Science.gov (United States)

    Vogler, Stefan

    2016-01-01

    Using document analysis and ethnographic field work, this article examines the debate within the LGBTQ community of Kansas City over the decision to hold its Pride festival in the Power and Light District (P&L), a renewed downtown area with a controversial dress code. Despite the developers' and city's goals of creating a cosmopolitan urban space that welcomed diverse populations, the P&L acquired a reputation as an anti-Black, anti-queer space due to its dress code and redevelopment history. I argue that the debate surrounding this controversy reveals limits to notions of diversity and diverging approaches to sexual politics within the LGBTQ community that are normally obscured by political actors within the movement but that work to create symbolic boundaries that exclude "non-respectable" members of the LGBTQ population. Recovering queer perspectives allows us to imagine a more capacious definition of diversity and inclusion, both within the LGBTQ movement and in urban space.

  4. Community-based participatory research and user-centered design in a diabetes medication information and decision tool.

    Science.gov (United States)

    Henderson, Vida A; Barr, Kathryn L; An, Lawrence C; Guajardo, Claudia; Newhouse, William; Mase, Rebecca; Heisler, Michele

    2013-01-01

    Together, community-based participatory research (CBPR), user-centered design (UCD), and health information technology (HIT) offer promising approaches to improve health disparities in low-resource settings. This article describes the application of CBPR and UCD principles to the development of iDecide/Decido, an interactive, tailored, web-based diabetes medication education and decision support tool delivered by community health workers (CHWs) to African American and Latino participants with diabetes in Southwest and Eastside Detroit. The decision aid is offered in English or Spanish and is delivered on an iPad in participants' homes. The overlapping principles of CBPR and UCD used to develop iDecide/Decido include a user-focused or community approach, equitable academic and community partnership in all study phases, an iterative development process that relies on input from all stakeholders, and a program experience that is specified, adapted, and implemented with the target community. Collaboration between community members, researchers, and developers is especially evident in the program's design concept, animations, pictographs, issue cards, goal setting, tailoring, and additional CHW tools. The principles of CBPR and UCD can be successfully applied in developing health information tools that are easy to use and understand, interactive, and target health disparities.

  5. Responses of Soil Microbial Community Structure and Diversity to Agricultural Deintensification

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Jian; S.HU; RUI Wen-Yi; C.TU; H.G.DIAB; F.J.LOUWS; J.P.MUELLER; N.CREAMER; M.BELL; M.G.WAGGER

    2005-01-01

    Using a scheme of agricultural fields with progressively less intensive management (deintensification), different management practices in six agroecosystems located near Goldsboro, NC, USA were tested in a large-scale experiment, including two cash-grain cropping systems employing either tillage (CT) or no-tillage (NT), an organic farming system (OR), an integrated cropping system with animals (IN), a successional field (SU), and a plantation woodlot (WO). Microbial phospholipid fatty acid (PLFA) profiles and substrate utilization patterns (BIOLOG ECO plates) were measured to examine the effects of deintensification on the structure and diversity of soil microbial communities. Principle component analyses of PLFA and BIOLOG data showed that the microbial community structure diverged among the soils of the six systems.Lower microbial diversity was found in lowly managed ecosystem than that in intensive and moderately managed agroecosystems, and both fungal contribution to the total identified PLFAs and the ratio of microbial biomass C/N increased along with agricultural deintensification. Significantly higher ratios of C/N (P < 0.05) were found in the WO and SU systems, and for fungal/bacterial PLFAs in the WO system (P < 0.05). There were also significant decreases (P < 0.05)along with agricultural deintensification for contributions of total bacterial and gram positive (G+) bacterial PLFAs.Agricultural deintensification could facilitate the development of microbial communities that favor soil fungi over bacteria.

  6. Diversity of Extremely Halophilic Archaeal and Bacterial Communities from Commercial Salts.

    Science.gov (United States)

    Gibtan, Ashagrie; Park, Kyounghee; Woo, Mingyeong; Shin, Jung-Kue; Lee, Dong-Woo; Sohn, Jae Hak; Song, Minjung; Roh, Seong Woon; Lee, Sang-Jae; Lee, Han-Seung

    2017-01-01

    Salting is one of the oldest food preservation techniques. However, salt is also the source of living halophilic microorganisms that may affect human health. In order to determine the microbial communities of commercial salts, an investigation were done using amplicon sequencing approach in four commercial salts: Ethiopian Afdera salt (EAS), Ethiopian rock salt (ERS), Korean Jangpan salt (KJS), and Korean Topan salt (KTS). Using domain-specific primers, a region of the 16S rRNA gene was amplified and sequenced using a Roche 454 instrument. The results indicated that these microbial communities contained 48.22-61.4% Bacteria, 37.72-51.26% Archaea, 0.51-0.86% Eukarya, and 0.005-0.009% unclassified reads. Among bacteria, the communities in these salts were dominated by the phyla Proteobacteria, Bacteroidetes, Actinobacteria , and Firmicutes . Of the archaea, 91.58% belonged to the class Halobacteria , whereas the remaining 7.58, 0.83, and 0.01% were Nanoarchaea, Methanobacteria , and Thermococci , respectively. This comparison of microbial diversity in salts from two countries showed the presence of many archaeal and bacterial genera that occurred in salt samples from one country but not the other. The bacterial genera Enterobacter and Halovibrio were found only in Korean and Ethiopian salts, respectively. This study indicated the occurrence and diversity of halophilic bacteria and archaea in commercial salts that could be important in the gastrointestinal tract after ingestion.

  7. Long-term nitrogen amendment alters the diversity and assemblage of soil bacterial communities in tallgrass prairie.

    Directory of Open Access Journals (Sweden)

    Joseph D Coolon

    Full Text Available Anthropogenic changes are altering the environmental conditions and the biota of ecosystems worldwide. In many temperate grasslands, such as North American tallgrass prairie, these changes include alteration in historically important disturbance regimes (e.g., frequency of fires and enhanced availability of potentially limiting nutrients, particularly nitrogen. Such anthropogenically-driven changes in the environment are known to elicit substantial changes in plant and consumer communities aboveground, but much less is known about their effects on soil microbial communities. Due to the high diversity of soil microbes and methodological challenges associated with assessing microbial community composition, relatively few studies have addressed specific taxonomic changes underlying microbial community-level responses to different fire regimes or nutrient amendments in tallgrass prairie. We used deep sequencing of the V3 region of the 16S rRNA gene to explore the effects of contrasting fire regimes and nutrient enrichment on soil bacterial communities in a long-term (20 yrs experiment in native tallgrass prairie in the eastern Central Plains. We focused on responses to nutrient amendments coupled with two extreme fire regimes (annual prescribed spring burning and complete fire exclusion. The dominant bacterial phyla identified were Proteobacteria, Verrucomicrobia, Bacteriodetes, Acidobacteria, Firmicutes, and Actinobacteria and made up 80% of all taxa quantified. Chronic nitrogen enrichment significantly impacted bacterial community diversity and community structure varied according to nitrogen treatment, but not phosphorus enrichment or fire regime. We also found significant responses of individual bacterial groups including Nitrospira and Gammaproteobacteria to long-term nitrogen enrichment. Our results show that soil nitrogen enrichment can significantly alter bacterial community diversity, structure, and individual taxa abundance, which have

  8. Using a social marketing framework to evaluate recruitment of a prospective study of genetic counseling and testing for the deaf community

    Science.gov (United States)

    2013-01-01

    Background Recruiting deaf and hard-of-hearing participants, particularly sign language-users, for genetics health service research is challenging due to communication barriers, mistrust toward genetics, and researchers’ unfamiliarity with deaf people. Feelings of social exclusion and lack of social cohesion between researchers and the Deaf community are factors to consider. Social marketing is effective for recruiting hard-to-reach populations because it fosters social inclusion and cohesion by focusing on the targeted audience’s needs. For the deaf population this includes recognizing their cultural and linguistic diversity, their geography, and their systems for information exchange. Here we use concepts and language from social marketing to evaluate our effectiveness to engage a U.S. deaf population in a prospective, longitudinal genetic counseling and testing study. Methods The study design was interpreted in terms of a social marketing mix of Product, Price, Place, and Promotion. Price addressed linguistic diversity by including a variety of communication technologies and certified interpreters to facilitate communication; Place addressed geography by including community-based participation locations; Promotion addressed information exchange by using multiple recruitment strategies. Regression analyses examined the study design’s effectiveness in recruiting a culturally and linguistically diverse sample. Results 271 individuals were enrolled, with 66.1% American Sign Language (ASL)-users, 19.9% ASL + English-users, 12.6% English-users. Language was significantly associated with communication technology, participation location, and recruitment. Videophone and interpreters were more likely to be used for communication between ASL-users and researchers while voice telephone and no interpreters were preferred by English-users (Price). ASL-users were more likely to participate in community-based locations while English-users preferred medically

  9. Changes in diversity, abundance, and structure of soil bacterial communities in Brazilian Savanna under different land use systems.

    Science.gov (United States)

    Rampelotto, Pabulo Henrique; de Siqueira Ferreira, Adão; Barboza, Anthony Diego Muller; Roesch, Luiz Fernando Wurdig

    2013-10-01

    The Brazilian Savanna, also known as "Cerrado", is the richest and most diverse savanna in the world and has been ranked as one of the main hotspots of biodiversity. The Cerrado is a representative biome in Central Brazil and the second largest biome in species diversity of South America. Nevertheless, large areas of native vegetation have been converted to agricultural land including grain production, livestock, and forestry. In this view, understanding how land use affects microbial communities is fundamental for the sustainable management of agricultural ecosystems. The aim of this work was to analyze and compare the soil bacterial communities from the Brazilian Cerrado associated with different land use systems using high throughput pyrosequencing of 16S rRNA genes. Relevant differences were observed in the abundance and structure of bacterial communities in soils under different land use systems. On the other hand, the diversity of bacterial communities was not relevantly changed among the sites studied. Land use systems had also an important impact on specific bacterial groups in soil, which might change the soil function and the ecological processes. Acidobacteria, Proteobacteria, and Actinobacteria were the most abundant groups in the Brazilian Cerrado. These findings suggest that more important than analyzing the general diversity is to analyze the composition of the communities. Since soil type was the same among the sites, we might assume that land use was the main factor defining the abundance and structure of bacterial communities.

  10. Mineralogic control on abundance and diversity of surface-adherent microbial communities

    Science.gov (United States)

    Mauck, Brena S.; Roberts, Jennifer A.

    2007-01-01

    In this study, we investigated the role of mineral-bound P and Fe in defining microbial abundance and diversity in a carbon-rich groundwater. Field colonization experiments of initially sterile mineral surfaces were combined with community structure characterization of the attached microbial population. Silicate minerals containing varying concentrations of P (∼1000 ppm P) and Fe (∼4 wt % Fe 2 O3), goethite (FeOOH), and apatite [Ca5(PO4)3(OH)] were incubated for 14 months in three biogeochemically distinct zones within a petroleum-contaminated aquifer. Phospholipid fatty acid analysis of incubated mineral surfaces and groundwater was used as a measure of microbial community structure and biomass. Microbial biomass on minerals exhibited distinct trends as a function of mineralogy depending on the environment of incubation. In the carbon-rich, aerobic groundwater attached biomass did not correlate to the P- or Fe- content of the mineral. In the methanogenic groundwater, however, biomass was most abundant on P-containing minerals. Similarly, in the Fe-reducing groundwater a correlation between Fe-content and biomass was observed. The community structure of the mineral-adherent microbial population was compared to the native groundwater community. These two populations were significantly different regardless of mineralogy, suggesting differentiation of the planktonic community through attachment, growth, and death of colonizing cells. Biomarkers specific for dissimilatory Fe-reducing bacteria native to the aquifer were identified only on Fe-containing minerals in the Fe-reducing groundwater. These results demonstrate that the trace nutrient content of minerals affects both the abundance and diversity of surface-adherent microbial communities. This behavior may be a means to access limiting nutrients from the mineral, creating a niche for a particular microbial population. These results suggest that heterogeneity of microbial populations and their associated

  11. Diversity and stability of coral endolithic microbial communities at a naturally high pCO2 reef.

    Science.gov (United States)

    Marcelino, Vanessa Rossetto; Morrow, Kathleen M; van Oppen, Madeleine J H; Bourne, David G; Verbruggen, Heroen

    2017-10-01

    The health and functioning of reef-building corals is dependent on a balanced association with prokaryotic and eukaryotic microbes. The coral skeleton harbours numerous endolithic microbes, but their diversity, ecological roles and responses to environmental stress, including ocean acidification (OA), are not well characterized. This study tests whether pH affects the diversity and structure of prokaryotic and eukaryotic algal communities associated with skeletons of Porites spp. using targeted amplicon (16S rRNA gene, UPA and tufA) sequencing. We found that the composition of endolithic communities in the massive coral Porites spp. inhabiting a naturally high pCO 2 reef (avg. pCO 2 811 μatm) is not significantly different from corals inhabiting reference sites (avg. pCO 2 357 μatm), suggesting that these microbiomes are less disturbed by OA than previously thought. Possible explanations may be that the endolithic microhabitat is highly homeostatic or that the endolithic micro-organisms are well adapted to a wide pH range. Some of the microbial taxa identified include nitrogen-fixing bacteria (Rhizobiales and cyanobacteria), algicidal bacteria in the phylum Bacteroidetes, symbiotic bacteria in the family Endozoicomoniaceae, and endolithic green algae, considered the major microbial agent of reef bioerosion. Additionally, we test whether host species has an effect on the endolithic community structure. We show that the endolithic community of massive Porites spp. is substantially different and more diverse than that found in skeletons of the branching species Seriatopora hystrix and Pocillopora damicornis. This study reveals highly diverse and structured microbial communities in Porites spp. skeletons that are possibly resilient to OA. © 2017 John Wiley & Sons Ltd.

  12. Temporal dynamics of soil nematode communities in a grassland plant diversity experiment.

    NARCIS (Netherlands)

    Viketoft, M.; Sohlenius, B.; Bostrom, S.; Palmborg, C.; Bengtsson, J.; Berg, M.P.; Kuss-Danell, K.

    2011-01-01

    We report here on an 8-year study examining links between plant and nematode communities in a grassland plant diversity experiment, located in the north of Sweden on previous agricultural soil. The examined plots contained 1, 4 and 12 common grassland plant species from three functional groups;

  13. A Tangled Path: Negotiating Leadership for, in, of, and with Diverse Communities

    Science.gov (United States)

    Goddard, J. Tim

    2015-01-01

    This article addresses issues of educational leadership in postcolonial and post-conflict environments. The focus relates to large-scale testing protocols, diversity in schools, asset-based community development, and communications technology. The article highlights the importance of context to the tenets of social justice, equitable human…

  14. SPECIES DIVERSITY AND COMMUNITY STRUCTURE OF FRUIT-FEEDING BUTTERFLIES (LEPIDOPTERA: NYMPHALIDAE IN AN EASTERN AMAZONIAN FOREST

    Directory of Open Access Journals (Sweden)

    LUCAS PEREIRA MARTINS

    Full Text Available ABSTRACT Deforestation has negative impacts on diversity and community patterns of several taxa. In the eastern Amazon, where much deforestation is predicted for the coming years, forests patches may be essential to maintain the local biodiversity. Despite increasing concerns about the conservation of threatened areas, few studies have been performed to analyze the communities of diversified groups, such as insects, in the eastern Amazon. Here, we investigated species diversity and community structure of fruit-feeding butterflies, a well-known bioindicator group, in a threatened remnant of an eastern Amazonian forest located on Maranhão Island, northeastern Brazil. Fruit-feeding butterflies were sampled monthly for one year. Diversity and evenness indices, richness estimators, rarefaction curve, and rank-abundance plot were used to describe community structure in the study area. We captured 529 fruit-feeding butterflies in four subfamilies, 23 genera and 34 species. The three most abundant species, Hamadryas februa, Hamadryas feronia, and Hermeuptychia cf. atalanta are indicators of disturbed habitats and represented more than half of the collected individuals. Richness estimators revealed that between 87 and 94% of the fruit-feeding butterfly species were sampled, suggesting few additional records would be made for the area. Our results indicate that human-caused disturbances have altered local community patterns and provide baseline data for future research in threatened regions of the eastern Amazon.

  15. Marine protected areas increase temporal stability of community structure, but not density or diversity, of tropical seagrass fish communities.

    Directory of Open Access Journals (Sweden)

    Elisa Alonso Aller

    Full Text Available Marine protected areas (MPAs have been shown to increase long-term temporal stability of fish communities and enhance ecosystem resilience to anthropogenic disturbance. Yet, the potential ability of MPAs to buffer effects of environmental variability at shorter time scales remains widely unknown. In the tropics, the yearly monsoon cycle is a major natural force affecting marine organisms in tropical regions, and its timing and severity are predicted to change over the coming century, with potentially severe effects on marine organisms, ecosystems and ecosystem services. Here, we assessed the ability of MPAs to buffer effects of monsoon seasonality on seagrass-associated fish communities, using a field survey in two MPAs (no-take zones and two unprotected (open-access sites around Zanzibar (Tanzania. We assessed the temporal stability of fish density and community structure within and outside MPAs during three monsoon seasons in 2014-2015, and investigated several possible mechanisms that could regulate temporal stability. Our results show that MPAs did not affect fish density and diversity, but that juvenile fish densities were temporally more stable within MPAs. Second, fish community structure was more stable within MPAs for juvenile and adult fish, but not for subadult fish or the total fish community. Third, the observed effects may be due to a combination of direct and indirect (seagrass-mediated effects of seasonality and, potentially, fluctuating fishing pressure outside MPAs. In summary, these MPAs may not have the ability to enhance fish density and diversity and to buffer effects of monsoon seasonality on the whole fish community. However, they may increase the temporal stability of certain groups, such as juvenile fish. Consequently, our results question whether MPAs play a general role in the maintenance of biodiversity and ecosystem functioning under changing environmental conditions in tropical seagrass fish communities.

  16. The impact of plant chemical diversity on plant-herbivore interactions at the community level.

    Science.gov (United States)

    Salazar, Diego; Jaramillo, Alejandra; Marquis, Robert J

    2016-08-01

    Understanding the role of diversity in ecosystem processes and species interactions is a central goal of ecology. For plant-herbivore interactions, it has been hypothesized that when plant species diversity is reduced, loss of plant biomass to herbivores increases. Although long-standing, this hypothesis has received mixed support. Increasing plant chemical diversity with increasing plant taxonomic diversity is likely to be important for plant-herbivore interactions at the community level, but the role of chemical diversity is unexplored. Here we assess the effect of volatile chemical diversity on patterns of herbivore damage in naturally occurring patches of Piper (Piperaceae) shrubs in a Costa Rican lowland wet forest. Volatile chemical diversity negatively affected total, specialist, and generalist herbivore damage. Furthermore, there were differences between the effects of high-volatility and low-volatility chemical diversity on herbivore damage. High-volatility diversity reduced specialist herbivory, while low-volatility diversity reduced generalist herbivory. Our data suggest that, although increased plant diversity is expected to reduce average herbivore damage, this pattern is likely mediated by the diversity of defensive compounds and general classes of anti-herbivore traits, as well as the degree of specialization of the herbivores attacking those plants.

  17. Unusual metabolic diversity of hyperalkaliphilic microbial communities associated with subterranean serpentinization at The Cedars.

    Science.gov (United States)

    Suzuki, Shino; Ishii, Shun'ichi; Hoshino, Tatsuhiko; Rietze, Amanda; Tenney, Aaron; Morrill, Penny L; Inagaki, Fumio; Kuenen, J Gijs; Nealson, Kenneth H

    2017-11-01

    Water from The Cedars springs that discharge from serpentinized ultramafic rocks feature highly basic (pH=~12), highly reducing (E h serpentinizing system, was dominated by several bacterial taxa from the phyla OD1 ('Parcubacteria') and Chloroflexi. Members of the GPS1 community had, for the most part, the smallest genomes reported for their respective taxa, and encoded only archaeal (A-type) ATP synthases or no ATP synthases at all. Furthermore, none of the members encoded respiration-related genes and some of the members also did not encode key biosynthesis-related genes. In contrast, BS5, fed by shallow water, appears to have a community driven by hydrogen metabolism and was dominated by a diverse group of Proteobacteria similar to those seen in many terrestrial serpentinization sites. Our findings indicated that the harsh ultrabasic geological setting supported unexpectedly diverse microbial metabolic strategies and that the deep-water-fed springs supported a community that was remarkable in its unusual metagenomic and genomic constitution.

  18. 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.

  19. 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.

  20. Diversity and communities of foliar endophytic fungi from different agroecosystems of Coffea arabica L. in two regions of Veracruz, Mexico.

    Science.gov (United States)

    Saucedo-García, Aurora; Anaya, Ana Luisa; Espinosa-García, Francisco J; González, María C

    2014-01-01

    Over the past 20 years, the biodiversity associated with shaded coffee plantations and the role of diverse agroforestry types in biodiversity conservation and environmental services have been topics of debate. Endophytic fungi, which are microorganisms that inhabit plant tissues in an asymptomatic manner, form a part of the biodiversity associated with coffee plants. Studies on the endophytic fungi communities of cultivable host plants have shown variability among farming regions; however, the variability in fungal endophytic communities of coffee plants among different coffee agroforestry systems is still poorly understood. As such, we analyzed the diversity and communities of foliar endophytic fungi inhabiting Coffea arabica plants growing in the rustic plantations and simple polycultures of two regions in the center of Veracruz, Mexico. The endophytic fungi isolates were identified by their morphological traits, and the majority of identified species correspond to species of fungi previously reported as endophytes of coffee leaves. We analyzed and compared the colonization rates, diversity, and communities of endophytes found in the different agroforestry systems and in the different regions. Although the endophytic diversity was not fully recovered, we found differences in the abundance and diversity of endophytes among the coffee regions and differences in richness between the two different agroforestry systems of each region. No consistent pattern of community similarity was found between the coffee agroforestry systems, but we found that rustic plantations shared the highest number of morphospecies. The results suggest that endophyte abundance, richness, diversity, and communities may be influenced predominantly by coffee region, and to a lesser extent, by the agroforestry system. Our results contribute to the knowledge of the relationships between agroforestry systems and biodiversity conservation and provide information regarding some endophytic fungi and

  1.   Diversity and composition of palm communities (Arecaceae) in Quintana Roo Mexico

    DEFF Research Database (Denmark)

    Alvarado, Arturo A.; Calvo, Luz M.; Duno, Rodrigo

      We compared composition and diversity of palm (Arecaceae) communities in three forest types along a gradient from dry deciduous, over intermediate to wet evergreen forest in Quintana Roo, Mexico. In forty-nine 5×500-m transects, we counted 52,612 individuals representing 14 species in 11 genera...

  2. Microbial community diversity and composition varies with habitat characteristics and biofilm function in macrophyte-rich streams

    DEFF Research Database (Denmark)

    Levi, Peter S.; Starnawski, Piotr; Poulsen, Britta

    2017-01-01

    Biofilms in streams play an integral role in ecosystem processes and function yet few studies have investigated the broad diversity of these complex prokaryotic and eukaryotic microbial communities. Physical habitat characteristics can affect the composition and abundance of microorganisms...... in these biofilms by creating microhabitats. Here we describe the prokaryotic and eukaryotic microbial diversity of biofilms in sand and macrophyte habitats (i.e. epipsammon and epiphyton, respectively) in five macrophyte-rich streams in Jutland, Denmark. The macrophyte species varied in growth morphology, C......:N stoichiometry, and preferred stream habitat, providing a range in environmental conditions for the epiphyton. Among all habitats and streams, the prokaryotic communities were dominated by common phyla, including Alphaproteobacteria, Bacteriodetes, and Gammaproteobacteria, while the eukaryotic communities were...

  3. Vulnerability- and Diversity-Aware Anonymization of Personally Identifiable Information for Improving User Privacy and Utility of Publishing Data

    Science.gov (United States)

    Majeed, Abdul; Ullah, Farman; Lee, Sungchang

    2017-01-01

    Personally identifiable information (PII) affects individual privacy because PII combinations may yield unique identifications in published data. User PII such as age, race, gender, and zip code contain private information that may assist an adversary in determining the user to whom such information relates. Each item of user PII reveals identity differently, and some types of PII are highly identity vulnerable. More vulnerable types of PII enable unique identification more easily, and their presence in published data increases privacy risks. Existing privacy models treat all types of PII equally from an identity revelation point of view, and they mainly focus on hiding user PII in a crowd of other users. Ignoring the identity vulnerability of each type of PII during anonymization is not an effective method of protecting user privacy in a fine-grained manner. This paper proposes a new anonymization scheme that considers the identity vulnerability of PII to effectively protect user privacy. Data generalization is performed adaptively based on the identity vulnerability of PII as well as diversity to anonymize data. This adaptive generalization effectively enables anonymous data, which protects user identity and private information disclosures while maximizing the utility of data for performing analyses and building classification models. Additionally, the proposed scheme has low computational overheads. The simulation results show the effectiveness of the scheme and verify the aforementioned claims. PMID:28481298

  4. Vulnerability- and Diversity-Aware Anonymization of Personally Identifiable Information for Improving User Privacy and Utility of Publishing Data

    Directory of Open Access Journals (Sweden)

    Abdul Majeed

    2017-05-01

    Full Text Available Personally identifiable information (PII affects individual privacy because PII combinations may yield unique identifications in published data. User PII such as age, race, gender, and zip code contain private information that may assist an adversary in determining the user to whom such information relates. Each item of user PII reveals identity differently, and some types of PII are highly identity vulnerable. More vulnerable types of PII enable unique identification more easily, and their presence in published data increases privacy risks. Existing privacy models treat all types of PII equally from an identity revelation point of view, and they mainly focus on hiding user PII in a crowd of other users. Ignoring the identity vulnerability of each type of PII during anonymization is not an effective method of protecting user privacy in a fine-grained manner. This paper proposes a new anonymization scheme that considers the identity vulnerability of PII to effectively protect user privacy. Data generalization is performed adaptively based on the identity vulnerability of PII as well as diversity to anonymize data. This adaptive generalization effectively enables anonymous data, which protects user identity and private information disclosures while maximizing the utility of data for performing analyses and building classification models. Additionally, the proposed scheme has low computational overheads. The simulation results show the effectiveness of the scheme and verify the aforementioned claims.

  5. Pyrosequencing reveals highly diverse and species-specific microbial communities in sponges from the Red Sea

    KAUST Repository

    Lee, Onon

    2010-11-18

    Marine sponges are associated with a remarkable array of microorganisms. Using a tag pyrosequencing technology, this study was the first to investigate in depth the microbial communities associated with three Red Sea sponges, Hyrtios erectus, Stylissa carteri and Xestospongia testudinaria. We revealed highly diverse sponge-associated bacterial communities with up to 1000 microbial operational taxonomic units (OTUs) and richness estimates of up to 2000 species. Altogether, 26 bacterial phyla were detected from the Red Sea sponges, 11 of which were absent from the surrounding sea water and 4 were recorded in sponges for the first time. Up to 100 OTUs with richness estimates of up to 300 archaeal species were revealed from a single sponge species. This is by far the highest archaeal diversity ever recorded for sponges. A non-negligible proportion of unclassified reads was observed in sponges. Our results demonstrated that the sponge-associated microbial communities remained highly consistent in the same sponge species from different locations, although they varied at different degrees among different sponge species. A significant proportion of the tag sequences from the sponges could be assigned to one of the sponge-specific clusters previously defined. In addition, the sponge-associated microbial communities were consistently divergent from those present in the surrounding sea water. Our results suggest that the Red Sea sponges possess highly sponge-specific or even sponge-species-specific microbial communities that are resistant to environmental disturbance, and much of their microbial diversity remains to be explored. © 2011 International Society for Microbial Ecology All rights reserved.

  6. Spatial pattern affects diversity-productivity relationships in experimental meadow communities

    Czech Academy of Sciences Publication Activity Database

    Lamošová, T.; Doležal, Jiří; Lanta, V.; Lepš, Jan

    2010-01-01

    Roč. 36, č. 3 (2010), s. 325-332 ISSN 1146-609X R&D Projects: GA AV ČR IAA600050802; GA ČR GA526/09/0963; GA ČR GA206/09/1642; GA ČR GA526/07/0808 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50070508 Keywords : functional-groups richness * species-diversity * experimental plant-communities Subject RIV: EF - Botanics Impact factor: 1.460, year: 2010

  7. Urbanization reduces and homogenizes trait diversity in stream macroinvertebrate communities.

    Science.gov (United States)

    Barnum, Thomas R; Weller, Donald E; Williams, Meghan

    2017-12-01

    More than one-half of the world's population lives in urban areas, so quantifying the effects of urbanization on ecological communities is important for understanding whether anthropogenic stressors homogenize communities across environmental and climatic gradients. We examined the relationship of impervious surface coverage (a marker of urbanization) and the structure of stream macroinvertebrate communities across the state of Maryland and within each of Maryland's three ecoregions: Coastal Plain, Piedmont, and Appalachian, which differ in stream geomorphology and community composition. We considered three levels of trait organization: individual traits, unique combinations of traits, and community metrics (functional richness, functional evenness, and functional divergence) and three levels of impervious surface coverage (low [10%]). The prevalence of an individual trait differed very little between low impervious surface and high impervious surface sites. The arrangement of trait combinations in community trait space for each ecoregion differed when impervious surface coverage was low, but the arrangement became more similar among ecoregions as impervious surface coverage increased. Furthermore, trait combinations that occurred only at low or medium impervious surface coverage were clustered in a subset of the community trait space, indicating that impervious surface affected the presence of only a subset of trait combinations. Functional richness declined with increasing impervious surface, providing evidence for environmental filtering. Community metrics that include abundance were also sensitive to increasing impervious surface coverage: functional divergence decreased while functional evenness increased. These changes demonstrate that increasing impervious surface coverage homogenizes the trait diversity of macroinvertebrate communities in streams, despite differences in initial community composition and stream geomorphology among ecoregions. Community

  8. Variation of Bacterial Community Diversity in Rhizosphere Soil of Sole-Cropped versus Intercropped Wheat Field after Harvest.

    Science.gov (United States)

    Yang, Zhenping; Yang, Wenping; Li, Shengcai; Hao, Jiaomin; Su, Zhifeng; Sun, Min; Gao, Zhiqiang; Zhang, Chunlai

    2016-01-01

    As the major crops in north China, spring crops are usually planted from April through May every spring and harvested in fall. Wheat is also a very common crop traditionally planted in fall or spring and harvested in summer year by year. This continuous cropping system exhibited the disadvantages of reducing the fertility of soil through decreasing microbial diversity. Thus, management of microbial diversity in the rhizosphere plays a vital role in sustainable crop production. In this study, ten common spring crops in north China were chosen sole-cropped and four were chosen intercropped with peanut in wheat fields after harvest. Denaturing gradient gel electrophoresis (DGGE) and DNA sequencing of one 16S rDNA fragment were used to analyze the bacterial diversity and species identification. DGGE profiles showed the bacterial community diversity in rhizosphere soil samples varied among various crops under different cropping systems, more diverse under intercropping system than under sole-cropping. Some intercropping-specific bands in DGGE profiles suggested that several bacterial species were stimulated by intercropping systems specifically. Furthermore, the identification of these dominant and functional bacteria by DNA sequencing indicated that intercropping systems are more beneficial to improve soil fertility. Compared to intercropping systems, we also observed changes in microbial community of rhizosphere soil under sole-crops. The rhizosphere bacterial community structure in spring crops showed a strong crop species-specific pattern. More importantly, Empedobacter brevis, a typical plant pathogen, was only found in the carrot rhizosphere, suggesting carrot should be sown prudently. In conclusion, our study demonstrated that crop species and cropping systems had significant effects on bacterial community diversity in the rhizosphere soils. We strongly suggest sorghum, glutinous millet and buckwheat could be taken into account as intercropping crops with peanut

  9. [Diversity and community structure of endophytic fungi from Taxus chinensis var. mairei].

    Science.gov (United States)

    2014-07-01

    A total of 628 endophytic fungi were isolated from 480 tissue segments of needles and branches of Taxus chinensis var. mairei. According to morphological characteristics and ITS sequences, they represented 43 taxa in 28 genera, of which 10 Hyphomycetes, 20 Coelomycetes, 12 Ascomycetes and 1 unknown fungus. Phomopsis mali was confirmed as the dominant species. In accordance with relative frequency, Alternaria alternata, Aureobasidium pullulans, Colletotrichum boninense, C. gloeosporioides, Epicoccum nigrum , Fungal sp., Fusarium lateritium, Glomerella cingulata, Magnaporthales sp. , Nigrospora oryzae, Pestalotiopsis maculiformans, P. microspora, Peyronellaea glomerata and Xylaria sp. 1 were more common in T. chinensis var. mairei. T. chinensis var. mairei were severely infected by endophytic fungi. Endophytic fungi were found in 81 percent of plant tissues with a high diversity. Distribution ranges of endophytic fungi were influenced by tissue properties. The colonization rate, richness, diversity of endophytic fungi in needles were obviously lower than in branches, and kinds of endophytic fungi between branches were more similar than those in needles, thus endophytic fungi had tissue preference. In addition, tissue age influenced the community structure of endophytic fungi. The elder branch tissues were, the higher colonization rate, richness, diversity of endophytic fungi were. Systematic studying the diversity and community structure of endophytic fungi in T. chinensis var. mairei and clarifying their distribution regularity in plant tissues would offer basic data and scientific basis for their development and utilization. Discussing the presence of fungal pathogens in healthy plant tissues would be of positive significance for source protection of T. chinensis var. mairei.

  10. Microbial diversity and community structure across environmental gradients in Bransfield Strait, Western Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Camila Negrão Signori

    2014-12-01

    Full Text Available The Southern Ocean is currently subject to intense investigations, mainly related to its importance for global biogeochemical cycles and its alarming rate of warming in response to climate change. Microbes play an essential role in the functioning of this ecosystem and are the main drivers of the biogeochemical cycling of elements. Yet, the diversity and abundance of microorganisms in this system remains poorly studied, in particular with regards to changes along environmental gradients. Here, we used amplicon sequencing of 16S rRNA gene tags using primers covering both Bacteria and Archaea to assess the composition and diversity of the microbial communities from four sampling depths (surface, the maximum and minimum of the oxygen concentration, and near the seafloor at ten oceanographic stations located in Bransfield Strait (northwest of the Antarctic Peninsula (AP and near the sea ice edge (north of the AP. Samples collected near the seafloor and at the oxygen minimum exhibited a higher diversity than those from the surface and oxygen maximum for both bacterial and archaeal communities. The main taxonomic groups identified below 100 m were Thaumarchaeota, Euryarchaeota and Proteobacteria (Gamma-, Delta-, Beta- and Alphaproteobacteria, whereas in the mixed layer above 100 m Bacteroidetes and Proteobacteria (mainly Alpha- and Gammaproteobacteria were found to be dominant. A combination of environmental factors seems to influence the microbial community composition. Our results help to understand how the dynamic seascape of the Southern Ocean shapes the microbial community composition and set a baseline for upcoming studies to evaluate the response of this ecosystem to future changes.

  11. Plant litter functional diversity effects on litter mass loss depend on the macro-detritivore community.

    Science.gov (United States)

    Patoine, Guillaume; Thakur, Madhav P; Friese, Julia; Nock, Charles; Hönig, Lydia; Haase, Josephine; Scherer-Lorenzen, Michael; Eisenhauer, Nico

    2017-11-01

    A better understanding of the mechanisms driving litter diversity effects on decomposition is needed to predict how biodiversity losses affect this crucial ecosystem process. In a microcosm study, we investigated the effects of litter functional diversity and two major groups of soil macro-detritivores on the mass loss of tree leaf litter mixtures. Furthermore, we tested the effects of litter trait community means and dissimilarity on litter mass loss for seven traits relevant to decomposition. We expected macro-detritivore effects on litter mass loss to be most pronounced in litter mixtures of high functional diversity. We used 24 leaf mixtures differing in functional diversity, which were composed of litter from four species from a pool of 16 common European tree species. Earthworms, isopods, or a combination of both were added to each litter combination for two months. Litter mass loss was significantly higher in the presence of earthworms than in that of isopods, whereas no synergistic effects of macro-detritivore mixtures were found. The effect of functional diversity of the litter material was highest in the presence of both macro-detritivore groups, supporting the notion that litter diversity effects are most pronounced in the presence of different detritivore species. Species-specific litter mass loss was explained by nutrient content, secondary compound concentration, and structural components. Moreover, dissimilarity in N concentrations increased litter mass loss, probably because detritivores having access to nutritionally diverse food sources. Furthermore, strong competition between the two macro-detritivores for soil surface litter resulted in a decrease of survival of both macro-detritivores. These results show that the effects of litter functional diversity on decomposition are contingent upon the macro-detritivore community and composition. We conclude that the temporal dynamics of litter trait diversity effects and their interaction with

  12. The effects of coastal development on sponge abundance, diversity, and community composition on Jamaican coral reefs.

    Science.gov (United States)

    Stubler, Amber D; Duckworth, Alan R; Peterson, Bradley J

    2015-07-15

    Over the past decade, development along the northern coast of Jamaica has accelerated, resulting in elevated levels of sedimentation on adjacent reefs. To understand the effects of this development on sponge community dynamics, we conducted surveys at three locations with varying degrees of adjacent coastal development to quantify species richness, abundance and diversity at two depths (8-10 m and 15-18 m). Sediment accumulation rate, total suspended solids and other water quality parameters were also quantified. The sponge community at the location with the least coastal development and anthropogenic influence was often significantly different from the other two locations, and exhibited higher sponge abundance, richness, and diversity. Sponge community composition and size distribution were statistically different among locations. This study provides correlative evidence that coastal development affects aspects of sponge community ecology, although the precise mechanisms are still unclear. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Flooding greatly affects the diversity of arbuscular mycorrhizal fungi communities in the roots of wetland plants.

    Directory of Open Access Journals (Sweden)

    Yutao Wang

    Full Text Available The communities of arbuscular mycorrhizal fungi (AMF colonizing the roots of three mangrove species were characterized along a tidal gradient in a mangrove swamp. A fragment, designated SSU-ITS-LSU, including part of the small subunit (SSU, the entire internal transcribed spacer (ITS and part of the large subunit (LSU of rDNA from samples of AMF-colonized roots was amplified, cloned and sequenced using AMF-specific primers. Similar levels of AMF diversity to those observed in terrestrial ecosystems were detected in the roots, indicating that the communities of AMF in wetland ecosystems are not necessarily low in diversity. In total, 761 Glomeromycota sequences were obtained, which grouped, according to phylogenetic analysis using the SSU-ITS-LSU fragment, into 23 phylotypes, 22 of which belonged to Glomeraceae and one to Acaulosporaceae. The results indicate that flooding plays an important role in AMF diversity, and its effects appear to depend on the degree (duration of flooding. Both host species and tide level affected community structure of AMF, indicating the presence of habitat and host species preferences.

  14. Salinity shapes microbial diversity and community structure in surface sediments of the Qinghai-Tibetan Lakes.

    Science.gov (United States)

    Yang, Jian; Ma, Li'an; Jiang, Hongchen; Wu, Geng; Dong, Hailiang

    2016-04-26

    Investigating microbial response to environmental variables is of great importance for understanding of microbial acclimatization and evolution in natural environments. However, little is known about how microbial communities responded to environmental factors (e.g. salinity, geographic distance) in lake surface sediments of the Qinghai-Tibetan Plateau (QTP). In this study, microbial diversity and community structure in the surface sediments of nine lakes on the QTP were investigated by using the Illumina Miseq sequencing technique and the resulting microbial data were statistically analyzed in combination with environmental variables. The results showed total microbial community of the studied lakes was significantly correlated (r = 0.631, P diversity and community structure in the studied samples. In addition, the abundant and rare taxa (OTUs with relative abundance higher than 1% and lower than 0.01% within one sample, respectively) were significantly (P < 0.05) correlated (r = 0.427 and 0.783, respectively) with salinity, suggesting rare taxa might be more sensitive to salinity than their abundant counterparts, thus cautions should be taken in future when evaluating microbial response (abundant vs. rare sub-communities) to environmental conditions.

  15. Biogeographical distribution and diversity of bacterial communities in surface sediments of the South China Sea.

    Science.gov (United States)

    Li, Tao; Wang, Peng

    2013-05-01

    This paper aims at an investigation of the features of bacterial communities in surface sediments of the South China Sea (SCS). In particular, biogeographical distribution patterns and the phylogenetic diversity of bacteria found in sediments collected from a coral reef platform, a continental slope, and a deep-sea basin were determined. Bacterial diversity was measured by an observation of 16S rRNA genes, and 18 phylogenetic groups were identified in the bacterial clone library. Planctomycetes, Deltaproteobacteria, candidate division OP11, and Alphaproteobacteria made up the majority of the bacteria in the samples, with their mean bacterial clones being 16%, 15%, 12%, and 9%, respectively. By comparison, the bacterial communities found in the SCS surface sediments were significantly different from other previously observed deep-sea bacterial communities. This research also emphasizes the fact that geographical factors have an impact on the biogeographical distribution patterns of bacterial communities. For instance, canonical correspondence analyses illustrated that the percentage of sand weight and water depth are important factors affecting the bacterial community composition. Therefore, this study highlights the importance of adequately determining the relationship between geographical factors and the distribution of bacteria in the world's seas and oceans.

  16. Effects of Predation by Protists on Prokaryotic Community Function, Structure, and Diversity in Anaerobic Granular Sludge.

    Science.gov (United States)

    Hirakata, Yuga; Oshiki, Mamoru; Kuroda, Kyohei; Hatamoto, Masashi; Kubota, Kengo; Yamaguchi, Takashi; Harada, Hideki; Araki, Nobuo

    2016-09-29

    Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates-ciliates frequently found in anoxic ecosystems-on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885-3,190 and 2,387-2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function.

  17. Performance analysis of an opportunistic multi-user cognitive network with multiple primary users

    KAUST Repository

    Khan, Fahd Ahmed

    2014-03-01

    Consider a multi-user underlay cognitive network where multiple cognitive users concurrently share the spectrum with a primary network with multiple users. The channel between the secondary network is assumed to have independent but not identical Nakagami-m fading. The interference channel between the secondary users (SUs) and the primary users is assumed to have Rayleigh fading. A power allocation based on the instantaneous channel state information is derived when a peak interference power constraint is imposed on the secondary network in addition to the limited peak transmit power of each SU. The uplink scenario is considered where a single SU is selected for transmission. This opportunistic selection depends on the transmission channel power gain and the interference channel power gain as well as the power allocation policy adopted at the users. Exact closed form expressions for the moment-generating function, outage performance, symbol error rate performance, and the ergodic capacity are derived. Numerical results corroborate the derived analytical results. The performance is also studied in the asymptotic regimes, and the generalized diversity gain of this scheduling scheme is derived. It is shown that when the interference channel is deeply faded and the peak transmit power constraint is relaxed, the scheduling scheme achieves full diversity and that increasing the number of primary users does not impact the diversity order. © 2014 John Wiley & Sons, Ltd.

  18. DiversePathsJ: diverse shortest paths for bioimage analysis.

    Science.gov (United States)

    Uhlmann, Virginie; Haubold, Carsten; Hamprecht, Fred A; Unser, Michael

    2018-02-01

    We introduce a formulation for the general task of finding diverse shortest paths between two end-points. Our approach is not linked to a specific biological problem and can be applied to a large variety of images thanks to its generic implementation as a user-friendly ImageJ/Fiji plugin. It relies on the introduction of additional layers in a Viterbi path graph, which requires slight modifications to the standard Viterbi algorithm rules. This layered graph construction allows for the specification of various constraints imposing diversity between solutions. The software allows obtaining a collection of diverse shortest paths under some user-defined constraints through a convenient and user-friendly interface. It can be used alone or be integrated into larger image analysis pipelines. http://bigwww.epfl.ch/algorithms/diversepathsj. michael.unser@epfl.ch or fred.hamprecht@iwr.uni-heidelberg.de. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

  19. Diversity of Communications, Diversity of Communities: Strategic Choices for Maximum Engagement

    Science.gov (United States)

    Bartel, B. A.; Unger, M.

    2017-12-01

    One of the challenges around the edges of scientific research is finding ways to effectively communicate about that research beyond the confines of a highly specialized scientific community. While peer-review, publication, and scientific conferences and workshops allow scientists to effectively share their research with colleagues in their field, these exclusive communications do little to reach outside of those circles. Amid increasing requirements to demonstrate the value of research, and threats to funding of both basic and applied research, it becomes increasingly important for scientists and those in fields related to science communications to find, and continually update, tools for effectively reaching broad audiences. Drawing on experiences in science communications from various entities including the National Center for Atmospheric Research, UNAVCO, and the National Snow and Ice Data Center, we will present lessons learned that can be applied to communications endeavors on all scales, from individual researchers to large organizations. We will explore various channels, messengers, messages, and methods we have used effectively to reach diverse and broad audiences. In thinking about science communications, it is critical to not only understand the audiences we are attempting to reach, but also to meet them in the spaces they frequent. Therefore, we have found value in diversifying communications strategies in order to engage with diverse demographics, using the means most likely to connect with each. Multiple communications channels and strategies reach different age groups, speakers of different languages, and audiences of varying knowledge, experience, age, and interest levels. For example, on social media, Instagram reaches a young demographic and Pinterest is an ideal way to reach educators. Diversity in communications products and channels also addresses varying learning styles and moods, offering opportunities for explanations (e.g, videos

  20. An Evaluation of a Community-Based Psycho-Educational Program for Users of Child Sexual Exploitation Material.

    Science.gov (United States)

    Gillespie, Steven M; Bailey, Alexandra; Squire, Tom; Carey, Melissa L; Eldridge, Hilary J; Beech, Anthony R

    2018-03-01

    Online sexual offenders represent an increasingly large proportion of all sexual offenders. Many of these offenders receive noncustodial sentences, and there is a growing need for community-based interventions. The aim of this study was to evaluate a psycho-educational program for community dwelling users of child sexual exploitation material (CSEM). A total of 92 adult male participants completed self-report measures at pre and post. A subset of participants also completed measures after a follow-up period. Results suggested benefits across depression, anxiety, and stress; social competency, including locus of control and self-esteem; and distorted attitudes. Furthermore, these effects remained 8 to 12 weeks following program completion. Our results suggest that CSEM users are amenable to treatment in the community and that there are beneficial outcomes in affective and interpersonal functioning following psycho-education. These factors represent treatment targets for sexual offenders and are recognized risk factors for contact sexual offense recidivism.

  1. Biogeographical diversity of leaf-associated microbial communities from salt-secreting Tamarix trees of the Dead Sea region.

    Science.gov (United States)

    Qvit-Raz, Noga; Finkel, Omri M; Al-Deeb, Taghleb M; Malkawi, Hanan I; Hindiyeh, Muna Y; Jurkevitch, Edouard; Belkin, Shimshon

    2012-02-01

    The leaves of Tamarix, a salt-secreting desert tree, form an extreme niche that harbors a unique microbial community. In view of the global distribution of this tree, its island-like phyllosphere is highly suitable for studying microbial diversity along geographical gradients. Here we present an analysis of microbial community diversity using leaf surface samples collected at six different sites, on both sides of the Dead Sea, over a period of one year. Biodiversity analysis of denaturing gradient gel electrophoresis (DGGE) patterns of the bacterial 16S rRNA gene revealed a significant degree of bacterial community similarity within trees sampled at the same site, much higher than the similarity between trees from different geographical locations. Statistical analysis indicated that the degree of similarity was negatively correlated with the distance between sampling sites, and that a weak correlation existed between diversity and leaf pH. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  2. Dynamics and diversity of microbial community succession in traditional fermentation of Shanxi aged vinegar.

    Science.gov (United States)

    Nie, Zhiqiang; Zheng, Yu; Du, Hongfu; Xie, Sankuan; Wang, Min

    2015-05-01

    The traditional fermentation of Shanxi aged vinegar (SAV), a well-known traditional Chinese vinegar, generally involves the preparation of starter daqu, starch saccharification, alcoholic fermentation (AF) and acetic acid fermentation (AAF). Dynamics and diversity of microbial community succession in daqu and other fermentation stages were investigated by denaturing gradient gel electrophoresis (DGGE). Results showed that eight bacterial genera and four fungal genera were found in daqu. However, Staphylococcus, Saccharopolyspora, Bacillus, Oceanobacillus, Enterobacter, Streptomyces, Eurotium, Monascus and Pichia in daqu were eradicated during AF. Four bacterial genera and three fungal genera were found in this stage. Weissella, Lactobacillus, Streptococcus, Saccharomyces, and Saccharomycopsis were the dominant microorganisms in the late stage of AF. During AAF, four bacterial genera and four fungal genera were found. Weissella, Streptococcus, Klebsiella, Escherichia, and Cladosporium gradually disappeared; the dominant microorganisms were Acetobacter, Lactobacillus, Saccharomycopsis, and Alternaria in the late stage of AAF. Alpha diversity metrics showed that fungal diversity in daqu was greater than that in AF and AAF. By contrast, bacterial diversity decreased from daqu to AF and increased in the first three days of AAF and then decreased. Hence, these results could help understand dynamics of microbial community succession in continuous fermentation of traditional Chinese vinegars. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Diverse Asian American Families and Communities: Culture, Structure, and Education (Part 1: Why They Differ)

    Science.gov (United States)

    Paik, Susan J.; Rahman, Zaynah; Kula, Stacy M.; Saito, L. Erika; Witenstein, Matthew A.

    2017-01-01

    Based on 11 diverse Asian American (AA) communities, this article discusses the similarities and differences across East, South, and Southeast Asians. Of two parts in this journal issue, Part 1 presents a review of literature and census data to understand the cultural and structural factors of different types of coethnic communities (strong, weak,…

  4. Experience and meaning of user involvement: some explorations from a community mental health project.

    Science.gov (United States)

    Truman, Carole; Raine, Pamela

    2002-05-01

    With an increased interest in and policy commitment to involving service users in the planning and delivery of health service provision, there is a clear need to explore both the rhetoric and realities of what user involvement entails. In the present paper, by drawing upon an evaluation of a community-based exercise facility for people with mental health problems, the authors explore ways in which the reality of user involvement is subject to a range of configurations within health services. The paper describes a piece of qualitative research that was undertaken within a participatory framework to explore the nature of user involvement within the facility. The data have been analysed using a grounded theory approach to provide insights into: the organisational context in which user involvement takes place; factors which encourage meaningful participation on the part of service users; perceived barriers to user involvement; and issues of sustainability and continuity. This research approach has enabled the authors to explore the views and experiences of users, service providers and referral agencies in relation to the nature and potential for user involvement. The findings illustrate ways in which user involvement may take place under both flexible and formal arrangements across a variety of activities. The present paper provides an account of some of the meanings and experiences of what 'successful' user participation may involve and the conditions which underpin 'success'. The authors conclude that successful and meaningful user involvement should enable and support users to recognise their existing skills, and to develop new ones, at a pace that suits their particular circumstances and personal resources. This process may require adaptation not only by organisations, but also by service providers and non-involved users.

  5. Diversity and Structure of Diazotrophic Communities in Mangrove Rhizosphere, Revealed by High-Throughput Sequencing.

    Science.gov (United States)

    Zhang, Yanying; Yang, Qingsong; Ling, Juan; Van Nostrand, Joy D; Shi, Zhou; Zhou, Jizhong; Dong, Junde

    2017-01-01

    Diazotrophic communities make an essential contribution to the productivity through providing new nitrogen. However, knowledge of the roles that both mangrove tree species and geochemical parameters play in shaping mangove rhizosphere diazotrophic communities is still elusive. Here, a comprehensive examination of the diversity and structure of microbial communities in the rhizospheres of three mangrove species, Rhizophora apiculata , Avicennia marina , and Ceriops tagal , was undertaken using high - throughput sequencing of the 16S rRNA and nifH genes. Our results revealed a great diversity of both the total microbial composition and the diazotrophic composition specifically in the mangrove rhizosphere. Deltaproteobacteria and Gammaproteobacteria were both ubiquitous and dominant, comprising an average of 45.87 and 86.66% of total microbial and diazotrophic communities, respectively. Sulfate-reducing bacteria belonging to the Desulfobacteraceae and Desulfovibrionaceae were the dominant diazotrophs. Community statistical analyses suggested that both mangrove tree species and additional environmental variables played important roles in shaping total microbial and potential diazotroph communities in mangrove rhizospheres. In contrast to the total microbial community investigated by analysis of 16S rRNA gene sequences, most of the dominant diazotrophic groups identified by nifH gene sequences were significantly different among mangrove species. The dominant diazotrophs of the family Desulfobacteraceae were positively correlated with total phosphorus, but negatively correlated with the nitrogen to phosphorus ratio. The Pseudomonadaceae were positively correlated with the concentration of available potassium, suggesting that diazotrophs potentially play an important role in biogeochemical cycles, such as those of nitrogen, phosphorus, sulfur, and potassium, in the mangrove ecosystem.

  6. Diversity and Structure of Diazotrophic Communities in Mangrove Rhizosphere, Revealed by High-Throughput Sequencing

    Directory of Open Access Journals (Sweden)

    Yanying Zhang

    2017-10-01

    Full Text Available Diazotrophic communities make an essential contribution to the productivity through providing new nitrogen. However, knowledge of the roles that both mangrove tree species and geochemical parameters play in shaping mangove rhizosphere diazotrophic communities is still elusive. Here, a comprehensive examination of the diversity and structure of microbial communities in the rhizospheres of three mangrove species, Rhizophora apiculata, Avicennia marina, and Ceriops tagal, was undertaken using high-throughput sequencing of the 16S rRNA and nifH genes. Our results revealed a great diversity of both the total microbial composition and the diazotrophic composition specifically in the mangrove rhizosphere. Deltaproteobacteria and Gammaproteobacteria were both ubiquitous and dominant, comprising an average of 45.87 and 86.66% of total microbial and diazotrophic communities, respectively. Sulfate-reducing bacteria belonging to the Desulfobacteraceae and Desulfovibrionaceae were the dominant diazotrophs. Community statistical analyses suggested that both mangrove tree species and additional environmental variables played important roles in shaping total microbial and potential diazotroph communities in mangrove rhizospheres. In contrast to the total microbial community investigated by analysis of 16S rRNA gene sequences, most of the dominant diazotrophic groups identified by nifH gene sequences were significantly different among mangrove species. The dominant diazotrophs of the family Desulfobacteraceae were positively correlated with total phosphorus, but negatively correlated with the nitrogen to phosphorus ratio. The Pseudomonadaceae were positively correlated with the concentration of available potassium, suggesting that diazotrophs potentially play an important role in biogeochemical cycles, such as those of nitrogen, phosphorus, sulfur, and potassium, in the mangrove ecosystem.

  7. Making User-Generated Content Communities Work in Higher Education - The Importance of Setting Incentives

    Science.gov (United States)

    Vom Brocke, Jan; White, Cynthia; Walker, Ute; Vom Brocke, Christina

    The concept of User-Generated Content (UGC) offers impressive potential for innovative learning and teaching scenarios in higher education. Examples like Wikipedia and Facebook illustrate the enormous effects of multiple users world-wide contributing to a pool of shared resources, such as videos and pictures and also lexicographical descriptions. Apart from single examples, however, the systematic use of these virtual technologies in higher education still needs further exploration. Only few examples display the successful application of UGC Communities at university scenarios. We argue that a major reason for this can be seen in the fact that the organizational dimension of setting up UGC Communities has widely been neglected so far. In particular, we indicate the need for incentive setting to actively involve students and achieve specific pedagogical objectives. We base our study on organizational theories and derive strategies for incentive setting that have been applied in a practical e-Learning scenario involving students from Germany and New Zealand.

  8. Unexpectedly high beta-diversity of root-associated fungal communities in the Bolivian Andes

    DEFF Research Database (Denmark)

    Barnes, Christopher James; Maldonado Goyzueta, Carla Brenda; Frøslev, Tobias Guldberg

    2016-01-01

    in microbial diversity. Here we assess the genetic, taxonomic and functional diversity of root-associated fungi surrounding Cinchona calisaya calisaya trees, a typical element of the intermediate altitudes of the Bolivian Yungas. We determine the relative effects of edaphic properties, climate, and geography...... variation respectively. Surprisingly, altitude does not influence community formation, and there is limited evidence that climate (precipitation and temperature) play a role. Our results suggest that sampling should be performed over a wide geographical and environmental range in order to capture the full...

  9. Diversity and bioprospection of fungal community present in oligotrophic soil of continental Antarctica

    Science.gov (United States)

    The diversity of fungal communities from different substrates in Antarctica were studied and their capability to produce bioactive compounds. A one hundred and one fungal isolates were identified by molecular analysis in 35 different fungal taxa from 20 genera. Pseudogymnoascus sp. 3, Pseudogymnoasc...

  10. Impact of a longitudinal community HIV intervention targeting injecting drug users' stage of change for condom and bleach use.

    Science.gov (United States)

    Jamner, M S; Wolitski, R J; Corby, N H

    1997-01-01

    To evaluate the impact of the Long Beach AIDS Community Demonstration Project, a community-based HIV-prevention intervention incorporating principles from the Transtheoretical model in its design and evaluation. Repeated cross-sectional sampling with matched intervention and comparison communities. Neighborhoods in Long Beach, California, having a high prevalence of drug abuse and prostitution. 3081 injecting drug users who were sexually active and/or shared injection equipment. Trained peer volunteers distributed fliers featuring role model stories targeted to the population's stage of change. Fliers were packaged with bleaching kits and/or condoms. Primary outcome measures were exposure to the intervention, condom carrying, and stage of change for disinfecting injection equipment with bleach and for using condoms with main and other partners. Toward the end of the study, 77% of injection drug users in the intervention area reported being exposed to the intervention. In the intervention area, rates of condom carrying increased from 10 to 27% (p project exposure had higher stage-of-change scores for using condoms with a main partner (p Project intervention for reaching injecting drug users in the community and for motivating the adoption of risk-reducing practices.

  11. Community diversity, structure and carbon footprint of nematode food web following reforestation on degraded Karst soil.

    Science.gov (United States)

    Hu, Ning; Li, Hui; Tang, Zheng; Li, Zhongfang; Tian, Jing; Lou, Yilai; Li, Jianwei; Li, Guichun; Hu, Xiaomin

    2016-06-17

    We examined community diversity, structure and carbon footprint of nematode food web along a chronosequence of T. Sinensis reforestation on degraded Karst. In general, after the reforestation: a serious of diversity parameters and community indices (Shannon-Weinier index (H'), structure index (SI), etc.) were elevated; biomass ratio of fungivores to bacterivores (FFC/BFC), and fungi to bacteria (F/B) were increased, and nematode channel ratio (NCR) were decreased; carbon footprints of all nematode trophic groups, and biomass of bacteria and fungi were increased. Our results indicate that the Karst aboveground vegetation restoration was accompanied with belowground nematode food web development: increasing community complexity, function and fungal dominance in decomposition pathway, and the driving forces included the bottom-up effect (resource control), connectedness of functional groups, as well as soil environments.

  12. Incarceration experiences among a community-recruited sample of injection drug users in Bangkok, Thailand

    Directory of Open Access Journals (Sweden)

    Lai Calvin

    2009-12-01

    Full Text Available Abstract Background Since 2003 Thailand has waged an aggressive "war on drugs" campaign focused on arresting and incarcerating suspected drug users and dealers. However, little is known about incarceration experiences among IDU in the wake of the recent war on drugs. Therefore, we sought to examine incarceration experiences among IDU in Bangkok, Thailand. Methods We examined the prevalence of incarceration among community-recruited IDU participating in the Mitsampan Community Research Project. Multivariate logistic regression was used to identify factors associated with a self-reported history of incarceration. We also examined the prevalence of injection drug use and syringe sharing within prisons. Results 252 IDU were recruited in August 2008; 66 (26.2% were female and the median age was 36.5 years. In total, 197 (78.2% participants reported a history of incarceration. In multivariate analyses, reporting a history of incarceration was associated with a history of compulsory drug treatment (adjusted odds ratio [AOR] = 4.93; 95% confidence interval [CI]: 1.95 - 12.48, non-fatal overdose (AOR = 3.69; 95%CI: 1.45 - 9.39, syringe sharing (AOR = 2.20; 95%CI: 1.12 - 4.32, and female gender (AOR = 0.41; 95%CI: 0.20 - 0.82. Among those who reported a history of incarceration, 59 (29.9% reported injection drug use in prison, and 48 (81.4% of these individuals reported sharing syringes in prison. Incarceration was not associated with the number of injections performed in the previous week (p = 0.202. Conclusion Over three-quarters of the IDU participating in this study reported a history of incarceration, and 30% of these individuals reported injection drug use within prison. Further, an alarmingly high level of syringe sharing within prison was reported, and incarceration was not associated with reductions in drug use. These findings provide further evidence of the need for community diversion strategies, as well as harm reduction programs, in Thai

  13. Urban-development-induced Changes in the Diversity and Composition of the Soil Bacterial Community in Beijing

    Science.gov (United States)

    Yan, Bing; Li, Junsheng; Xiao, Nengwen; Qi, Yue; Fu, Gang; Liu, Gaohui; Qiao, Mengping

    2016-12-01

    Numerous studies have implicated urbanization as a major cause of loss of biodiversity. Most of them have focused on plants and animals, even though soil microorganisms make up a large proportion of that biodiversity. However, it is unclear how the soil bacterial community is affected by urban development. Here, paired-end Illumina sequencing of the 16 S rRNA gene at V4 region was performed to study the soil microbial community across Beijing’s built-up area. Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Gemmatimonadetes, Verrucomicrobia, Planctomycetes, and Chloroflexi were the dominant phyla in all samples, but the relative abundance of these phyla differed significantly across these concentric zones. The diversity and composition of the soil bacterial community were found to be closely correlated with soil pH. Variance partitioning analysis suggested that urban ring roads contributed 5.95% of the bacterial community variation, and soil environmental factors explained 17.65% of the variation. The results of the current work indicate that urban development can alter the composition and diversity of the soil microbial community, and showed pH to be a key factor in the shaping of the composition of the soil bacterial community. Urban development did have a strong impact on the bacterial community of urban soil in Beijing.

  14. Effects of mercury contamination on the culturable heterotrophic, functional and genetic diversity of the bacterial community in soil

    DEFF Research Database (Denmark)

    Rasmussen, Lasse Dam; Sørensen, S. J.

    2001-01-01

    This study investigates the effect of mercury contamination on the culturable heterotrophic, functional and genetic diversity of the bacterial community in soil. The changes in diversity were monitored in soil microcosms, enriched with 25 mug Hg(II) g(-1) soil, over a period of 3 months...... by purification of total soil DNA and amplification of bacterial 16S rDNA fragments by polymerase chain reaction. Concentrations of bioavailable and total mercury were measured throughout the experiment. The effect on the culturable heterotrophic and genetic diversity was very similar, showing an immediate...... decrease after mercury addition but then slowly increasing throughout the entire experimental period. Pre-exposure levels were not reached within the time span of this investigation. The DGGE band pattern indicated that a shift in the community structure was responsible for recovered diversity. When...

  15. Elevational gradients in phylogenetic structure of ant communities reveal the interplay of biotic and abiotic constraints on diversity

    DEFF Research Database (Denmark)

    Machac, Antonin; Janda, Milan; Dunn, Robert R.

    2011-01-01

    A central focus of ecology and biogeography is to determine the factors that govern spatial variation in biodiversity. Here, we examined patterns of ant diversity along climatic gradients in three temperate montane systems: Great Smoky Mountains National Park (USA), Chiricahua Mountains (USA......), and Vorarlberg (Austria). To identify the factors which potentially shape these elevational diversity gradients, we analyzed patterns of community phylogenetic structure (i.e. the evolutionary relationships among species coexisting in local communities). We found that species at low-elevation sites tended...... to be evenly dispersed across phylogeny, suggesting that these communities are structured by interspecific competition. In contrast, species occurring at high-elevation sites tended to be more closely related than expected by chance, implying that these communities are structured primarily by environmental...

  16. Dry coniferous forest restoration and understory plant diversity: The importance of community heterogeneity and the scale of observation

    Science.gov (United States)

    Erich Kyle Dodson; David W. Peterson

    2010-01-01

    Maintaining understory plant species diversity is an important management goal as forest restoration and fuel reduction treatments are applied extensively to dry coniferous forests of western North America. However, understory diversity is a function of both local species richness (number of species in a sample unit) and community heterogeneity (beta diversity) at...

  17. Security and reliability analysis of diversity combining techniques in SIMO mixed RF/FSO with multiple users

    KAUST Repository

    Abd El-Malek, Ahmed H.; Salhab, Anas M.; Zummo, Salam A.; Alouini, Mohamed-Slim

    2016-01-01

    In this paper, we investigate the impact of different diversity combining techniques on the security and reliability analysis of a single-input-multiple-output (SIMO) mixed radio frequency (RF)/free space optical (FSO) relay network with opportunistic multiuser scheduling. In this model, the user of the best channel among multiple users communicates with a multiple antennas relay node over an RF link, and then, the relay node employs amplify-and-forward (AF) protocol in retransmitting the user data to the destination over an FSO link. Moreover, the authorized transmission is assumed to be attacked by a single passive RF eavesdropper equipped with multiple antennas. Therefore, the system security reliability trade-off analysis is investigated. Closed-form expressions for the system outage probability and the system intercept probability are derived. Then, the newly derived expressions are simplified to their asymptotic formulas at the high signal-to-noise- ratio (SNR) region. Numerical results are presented to validate the achieved exact and asymptotic results and to illustrate the impact of various system parameters on the system performance. © 2016 IEEE.

  18. Security and reliability analysis of diversity combining techniques in SIMO mixed RF/FSO with multiple users

    KAUST Repository

    Abd El-Malek, Ahmed H.

    2016-07-26

    In this paper, we investigate the impact of different diversity combining techniques on the security and reliability analysis of a single-input-multiple-output (SIMO) mixed radio frequency (RF)/free space optical (FSO) relay network with opportunistic multiuser scheduling. In this model, the user of the best channel among multiple users communicates with a multiple antennas relay node over an RF link, and then, the relay node employs amplify-and-forward (AF) protocol in retransmitting the user data to the destination over an FSO link. Moreover, the authorized transmission is assumed to be attacked by a single passive RF eavesdropper equipped with multiple antennas. Therefore, the system security reliability trade-off analysis is investigated. Closed-form expressions for the system outage probability and the system intercept probability are derived. Then, the newly derived expressions are simplified to their asymptotic formulas at the high signal-to-noise- ratio (SNR) region. Numerical results are presented to validate the achieved exact and asymptotic results and to illustrate the impact of various system parameters on the system performance. © 2016 IEEE.

  19. Support vector regression model of wastewater bioreactor performance using microbial community diversity indices: effect of stress and bioaugmentation.

    Science.gov (United States)

    Seshan, Hari; Goyal, Manish K; Falk, Michael W; Wuertz, Stefan

    2014-04-15

    The relationship between microbial community structure and function has been examined in detail in natural and engineered environments, but little work has been done on using microbial community information to predict function. We processed microbial community and operational data from controlled experiments with bench-scale bioreactor systems to predict reactor process performance. Four membrane-operated sequencing batch reactors treating synthetic wastewater were operated in two experiments to test the effects of (i) the toxic compound 3-chloroaniline (3-CA) and (ii) bioaugmentation targeting 3-CA degradation, on the sludge microbial community in the reactors. In the first experiment, two reactors were treated with 3-CA and two reactors were operated as controls without 3-CA input. In the second experiment, all four reactors were additionally bioaugmented with a Pseudomonas putida strain carrying a plasmid with a portion of the pathway for 3-CA degradation. Molecular data were generated from terminal restriction fragment length polymorphism (T-RFLP) analysis targeting the 16S rRNA and amoA genes from the sludge community. The electropherograms resulting from these T-RFs were used to calculate diversity indices - community richness, dynamics and evenness - for the domain Bacteria as well as for ammonia-oxidizing bacteria in each reactor over time. These diversity indices were then used to train and test a support vector regression (SVR) model to predict reactor performance based on input microbial community indices and operational data. Considering the diversity indices over time and across replicate reactors as discrete values, it was found that, although bioaugmentation with a bacterial strain harboring a subset of genes involved in the degradation of 3-CA did not bring about 3-CA degradation, it significantly affected the community as measured through all three diversity indices in both the general bacterial community and the ammonia-oxidizer community (

  20. Five-Factor Model personality profiles of drug users

    Directory of Open Access Journals (Sweden)

    Crum Rosa M

    2008-04-01

    Full Text Available Abstract Background Personality traits are considered risk factors for drug use, and, in turn, the psychoactive substances impact individuals' traits. Furthermore, there is increasing interest in developing treatment approaches that match an individual's personality profile. To advance our knowledge of the role of individual differences in drug use, the present study compares the personality profile of tobacco, marijuana, cocaine, and heroin users and non-users using the wide spectrum Five-Factor Model (FFM of personality in a diverse community sample. Method Participants (N = 1,102; mean age = 57 were part of the Epidemiologic Catchment Area (ECA program in Baltimore, MD, USA. The sample was drawn from a community with a wide range of socio-economic conditions. Personality traits were assessed with the Revised NEO Personality Inventory (NEO-PI-R, and psychoactive substance use was assessed with systematic interview. Results Compared to never smokers, current cigarette smokers score lower on Conscientiousness and higher on Neuroticism. Similar, but more extreme, is the profile of cocaine/heroin users, which score very high on Neuroticism, especially Vulnerability, and very low on Conscientiousness, particularly Competence, Achievement-Striving, and Deliberation. By contrast, marijuana users score high on Openness to Experience, average on Neuroticism, but low on Agreeableness and Conscientiousness. Conclusion In addition to confirming high levels of negative affect and impulsive traits, this study highlights the links between drug use and low Conscientiousness. These links provide insight into the etiology of drug use and have implications for public health interventions.

  1. Tree diversity and community characteristics in Talle Wildlife Sanctuary, Arunachal Pradesh, Eastern Himalaya, India

    Directory of Open Access Journals (Sweden)

    Gyati Yam

    2016-06-01

    Full Text Available This study was carried out in a temperate forest for enumeration of floristic diversity and community characteristics analysis of the Talle Wildlife Sanctuary. A random sampling approach was adopted. Altogether, 63 species were recorded from the sampled area (0.2 ha. Family dominance results showed that Lauraceae was the most dominant followed by Fagaceae. Seventy percent of species showed low frequency distribution and species having higher frequency classes were almost absent or represented by only a few species. Dominance distribution of species resulted in a log normal distribution pattern which further signifies that the forest community was heterogeneous in nature. Species Prediction and Diversity Estimation analysis categorized 80% of the species as a rare species group and 20% as abundant species group. Estimation of coefficient of variation showed that rare species have equal detection possibilities in the sampled area. Distribution of basal cover in different girth classes indicates a reverse trend to that of stand density. The results of this study show that the forest community composition is highly clustered and loosely colonized in nature.

  2. Connecting Satellite-Based Precipitation Estimates to Users

    Science.gov (United States)

    Huffman, George J.; Bolvin, David T.; Nelkin, Eric

    2018-01-01

    Beginning in 1997, the Merged Precipitation Group at NASA Goddard has distributed gridded global precipitation products built by combining satellite and surface gauge data. This started with the Global Precipitation Climatology Project (GPCP), then the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), and recently the Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM) mission (IMERG). This 20+-year (and on-going) activity has yielded an important set of insights and lessons learned for making state-of-the-art precipitation data accessible to the diverse communities of users. Merged-data products critically depend on the input sensors and the retrieval algorithms providing accurate, reliable estimates, but it is also important to provide ancillary information that helps users determine suitability for their application. We typically provide fields of estimated random error, and recently reintroduced the quality index concept at user request. Also at user request we have added a (diagnostic) field of estimated precipitation phase. Over time, increasingly more ancillary fields have been introduced for intermediate products that give expert users insight into the detailed performance of the combination algorithm, such as individual merged microwave and microwave-calibrated infrared estimates, the contributing microwave sensor types, and the relative influence of the infrared estimate.

  3. The association between income source and met need among community mental health service users in Ontario, Canada.

    Science.gov (United States)

    Durbin, Anna; Bondy, Susan J; Durbin, Janet

    2012-10-01

    We examined income source and match between recommended and received care among users of community mental health services. We conducted a secondary analysis of needs-based planning data on adults in Ontario community mental health programs from 2000 to 2002. The outcome was whether clients were severely underserved (yes/no) based on the match between level of care recommended and received. A logistic regression model investigated if income source predicted this outcome. 13% of clients were severely underserved. Over 40% were on public assistance and they had a higher risk of being severely undeserved than the others. Men were at greater risk. One aim of mental health reform is to increase access to care for vulnerable individuals. The finding that among users of community mental health services, individuals with public assistance income support are most vulnerable to being severely underserved should be considered by service planners and providers.

  4. Topographical Mapping of the Rainbow Trout (Oncorhynchus mykiss) Microbiome Reveals a Diverse Bacterial Community with Antifungal Properties in the Skin

    Science.gov (United States)

    Lowrey, Liam; Woodhams, Douglas C.; Tacchi, Luca

    2015-01-01

    The mucosal surfaces of wild and farmed aquatic vertebrates face the threat of many aquatic pathogens, including fungi. These surfaces are colonized by diverse symbiotic bacterial communities that may contribute to fight infection. Whereas the gut microbiome of teleosts has been extensively studied using pyrosequencing, this tool has rarely been employed to study the compositions of the bacterial communities present on other teleost mucosal surfaces. Here we provide a topographical map of the mucosal microbiome of an aquatic vertebrate, the rainbow trout (Oncorhynchus mykiss). Using 16S rRNA pyrosequencing, we revealed novel bacterial diversity at each of the five body sites sampled and showed that body site is a strong predictor of community composition. The skin exhibited the highest diversity, followed by the olfactory organ, gills, and gut. Flectobacillus was highly represented within skin and gill communities. Principal coordinate analysis and plots revealed clustering of external sites apart from internal sites. A highly diverse community was present within the epithelium, as demonstrated by confocal microscopy and pyrosequencing. Using in vitro assays, we demonstrated that two Arthrobacter sp. skin isolates, a Psychrobacter sp. strain, and a combined skin aerobic bacterial sample inhibit the growth of Saprolegnia australis and Mucor hiemalis, two important aquatic fungal pathogens. These results underscore the importance of symbiotic bacterial communities of fish and their potential role for the control of aquatic fungal diseases. PMID:26209676

  5. Multiuser hybrid switched-selection diversity systems

    KAUST Repository

    Shaqfeh, Mohammad

    2011-09-01

    A new multiuser scheduling scheme is proposed and analyzed in this paper. The proposed system combines features of conventional full-feedback selection-based diversity systems and reduced-feedback switch-based diversity systems. The new hybrid system provides flexibility in trading-off the channel information feedback overhead with the prospected multiuser diversity gains. The users are clustered into groups, and the users\\' groups are ordered into a sequence. Per-group feedback thresholds are used and optimized to maximize the system overall achievable rate. The proposed hybrid system applies switched diversity criterion to choose one of the groups, and a selection criterion to decide the user to be scheduled from the chosen group. Numerical results demonstrate that the system capacity increases as the number of users per group increases, but at the cost of more required feedback messages. © 2011 IEEE.

  6. Multiple Interests of Users in Collaborative Tagging Systems

    Science.gov (United States)

    Au Yeung, Ching-Man; Gibbins, Nicholas; Shadbolt, Nigel

    Performance of recommender systems depends on whether the user profiles contain accurate information about the interests of the users, and this in turn relies on whether enough information about their interests can be collected. Collaborative tagging systems allow users to use their own words to describe their favourite resources, resulting in some user-generated categorisation schemes commonly known as folksonomies. Folksonomies thus contain rich information about the interests of the users, which can be used to support various recommender systems. Our analysis of the folksonomy in Delicious reveals that the interests of a single user can be very diverse. Traditional methods for representing interests of users are usually not able to reflect such diversity. We propose a method to construct user profiles of multiple interests from folksonomies based on a network clustering technique. Our evaluation shows that the proposed method is able to generate user profiles which reflect the diversity of user interests and can be used as a basis of providing more focused recommendation to the users.

  7. Troubled Diversities, Multiple Identities and the Relevance of Royce: What Makes a Community Worth Caring about?

    Science.gov (United States)

    Raposa, Michael

    2012-01-01

    This article raises questions about what it means to be a diverse academic community and about why such diversity is worth struggling to achieve. The controversial arguments of Walter Benn Michaels are critically examined as a stimulus and prelude to considering the more constructive perspectives supplied by Amartya Sen and Josiah Royce. Royce's…

  8. Loyalty in Online Communities.

    Science.gov (United States)

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

    2017-05-01

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

  9. Optimal Multiuser Diversity in Multi-Cell MIMO Uplink Networks: User Scaling Law and Beamforming Design

    Directory of Open Access Journals (Sweden)

    Bang Chul Jung

    2017-07-01

    Full Text Available We introduce a distributed protocol to achieve multiuser diversity in a multicell multiple-input multiple-output (MIMO uplink network, referred to as a MIMO interfering multiple-access channel (IMAC. Assuming both no information exchange among base stations (BS and local channel state information at the transmitters for the MIMO IMAC, we propose a joint beamforming and user scheduling protocol, and then show that the proposed protocol can achieve the optimal multiuser diversity gain, i.e., KMlog(SNRlog N, as long as the number of mobile stations (MSs in a cell, N, scales faster than SNR K M − L 1 − ϵ for a small constant ϵ > 0, where M, L, K, and SNR denote the number of receive antennas at each BS, the number of transmit antennas at each MS, the number of cells, and the signal-to-noise ratio, respectively. Our result indicates that multiuser diversity can be achieved in the presence of intra-cell and inter-cell interference even in a distributed fashion. As a result, vital information on how to design distributed algorithms in interference-limited cellular environments is provided.

  10. Factors limiting deceased organ donation: focus groups' perspective from culturally diverse community.

    Science.gov (United States)

    Wong, L P

    2010-06-01

    In-depth understanding of cultural and religious factors limiting organ donation of three ethnic populations (Malay, Chinese, and Indian) in Southeast Asia is lacking. Identification of factors limiting organ donation among these three ethnic groups will provide insights into culturally appropriate strategies to promote acceptance of organ donation in a multiethnic Asian community. A total of 17 focus group discussions (105 participants) were conducted between September and December 2008. Participants were members of the general public aged 18 to 60 years, recruited through convenient sampling around the Klang Valley area of Malaysia. Although the majority had favorable attitudes toward deceased organ donation and transplantation, a diversity of myths and misinformation were unearthed from the discussions across the ethnic groups. These include perceived religious prohibition, cultural myths and misperceptions, fear of disfigurement, fear of surgery, distrust of the medical system, and family disapproval. Culture and religious beliefs played important prohibitive roles among those opposed to organ donations. There were distinctive ethnic differences in cultural and religious concerns regarding organ donation. Less-educated and rural groups appeared to have more misconceptions than the well-educated and the urban groups. Our findings may assist organ donation and transplantation organizations to reach diverse sociodemographic and ethnic communities with culture-specific information about organ donation. The involvement of community and religious leaders is critical in organ donation requests.

  11. pH dominates variation in tropical soil archaeal diversity and community structure.

    Science.gov (United States)

    Tripathi, Binu M; Kim, Mincheol; Lai-Hoe, Ang; Shukor, Nor A A; Rahim, Raha A; Go, Rusea; Adams, Jonathan M

    2013-11-01

    Little is known of the factors influencing soil archaeal community diversity and composition in the tropics. We sampled soils across a range of forest and nonforest environments in the equatorial tropics of Malaysia, covering a wide range of pH values. DNA was PCR-amplified for the V1-V3 region of the 16S rRNA gene, and 454-pyrosequenced. Soil pH was the best predictor of diversity and community composition of Archaea, being a stronger predictor than land use. Archaeal OTU richness was highest in the most acidic soils. Overall archaeal abundance in tropical soils (determined by qPCR) also decreased at higher pH. This contrasts with the opposite trend previously found in temperate soils. Thaumarcheota group 1.1b was more abundant in alkaline soils, whereas group 1.1c was only detected in acidic soils. These results parallel those found in previous studies in cooler climates, emphasizing niche conservatism among broad archaeal groups. Among the most abundant operational taxonomic units (OTUs), there was clear evidence of niche partitioning by pH. No individual OTU occurred across the entire range of pH values. Overall, the results of this study show that pH plays a major role in structuring tropical soil archaeal communities. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  12. Genetic diversity and temporal variation of the marine Synechococcus community in the subtropical coastal waters of Hong Kong.

    Science.gov (United States)

    Jing, Hongmei; Zhang, Rui; Pointing, Stephen B; Liu, Hongbin; Qian, Peiyuan

    2009-03-01

    The phylogenetic diversity of the marine Synechococcus community in the subtropical coastal waters of Hong Kong, China, was examined through intergenic transcribed spacer clone libraries. All the sequences obtained fell within both marine cluster A (MC-A) and B (MC-B), with MC-A phylotypes dominating throughout the year. Distinct phylogenetic lineages specific to Hong Kong waters were detected from both MC-A and MC-B. The highest Synechococcus community diversity occurred in December, but the highest Synechococcus abundance occurred in August. On the other hand, both the abundance and diversity of Synechococcus showed a minimum in February. The remarkable seasonal variations of Synechococcus diversity observed were likely the result of the changes of hydrographic condition modulated by monsoons. Principal component analysis revealed that the in situ abiotic water characteristics, especially salinity and water turbidity, explained much of the variability of the marine Synechococcus population diversity in Hong Kong coastal waters. In addition, the temporal changes of Synechococcus abundance were largely driven by water temperature.

  13. Effects of Predation by Protists on Prokaryotic Community Function, Structure, and Diversity in Anaerobic Granular Sludge

    Science.gov (United States)

    Hirakata, Yuga; Oshiki, Mamoru; Kuroda, Kyohei; Hatamoto, Masashi; Kubota, Kengo; Yamaguchi, Takashi; Harada, Hideki; Araki, Nobuo

    2016-01-01

    Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates—ciliates frequently found in anoxic ecosystems—on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885–3,190 and 2,387–2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function. PMID:27431197

  14. Drivers of temporal beta diversity of a benthic community in a seasonally hypoxic fjord

    Science.gov (United States)

    Chu, Jackson W. F.; Curkan, Curtis; Tunnicliffe, Verena

    2018-04-01

    Global expansion of oxygen-deficient (hypoxic) waters will have detrimental effects on marine life in the Northeast Pacific Ocean (NEP) where some of the largest proportional losses in aerobic habitat are predicted to occur. However, few in situ studies have accounted for the high environmental variability in this region while including natural community-assembly dynamics. Here, we present results from a 14-month deployment of a benthic camera platform tethered to the VENUS cabled observatory in the seasonally hypoxic Saanich Inlet. Our time series continuously recorded natural cycles of deoxygenation and reoxygenation that allowed us to test whether a community from the NEP showed hysteresis in its recovery compared to hypoxia-induced decline, and to address the processes driving temporal beta diversity under variable states of hypoxia. Using high-frequency ecological time series, we reveal (i) differences in the response and recovery of the epibenthic community are rate-limited by recovery of the sessile species assemblage; (ii) both environmental and biological processes influence community assembly patterns at multiple timescales; and (iii) interspecific processes can drive temporal beta diversity in seasonal hypoxia. Ultimately, our results illustrate how different timescale-dependent drivers can influence the response and recovery of a marine habitat under increasing stress from environmental change.

  15. Inventory of activation analysis facilities available in the European Community to Industrial users

    International Nuclear Information System (INIS)

    Pauwels, J.

    1975-01-01

    This inventory includes lists of activation equipment produced in the European Community, facilities available for industrial users and activation laboratories existing in the European companies. The aim of this inventory is to provide all information that may be useful, to companies interested in activation analysis, as well as to give an idea on existing routine applications and on the European market in facilities

  16. Modeling Users' Experiences with Interactive Systems

    CERN Document Server

    Karapanos, Evangelos

    2013-01-01

    Over the past decade the field of Human-Computer Interaction has evolved from the study of the usability of interactive products towards a more holistic understanding of how they may mediate desired human experiences.  This book identifies the notion of diversity in usersʼ experiences with interactive products and proposes methods and tools for modeling this along two levels: (a) interpersonal diversity in usersʽ responses to early conceptual designs, and (b) the dynamics of usersʼ experiences over time. The Repertory Grid Technique is proposed as an alternative to standardized psychometric scales for modeling interpersonal diversity in usersʼ responses to early concepts in the design process, and new Multi-Dimensional Scaling procedures are introduced for modeling such complex quantitative data. iScale, a tool for the retrospective assessment of usersʼ experiences over time is proposed as an alternative to longitudinal field studies, and a semi-automated technique for the analysis of the elicited exper...

  17. Elevated Atmospheric CO2 and Drought Affect Soil Microbial Community and Functional Diversity Associated with Glycine max

    Directory of Open Access Journals (Sweden)

    Junfeng Wang

    2017-12-01

    Full Text Available Abstract Under the background of climate change, the increase of atmospheric CO2 and drought frequency have been considered as significant influencers on the soil microbial communities and the yield and quality of crop. In this study, impacts of increased ambient CO2 and drought on soil microbial structure and functional diversity of a Stagnic Anthrosol were investigated in phytotron growth chambers, by testing two representative CO2 levels, three soil moisture levels, and two soil cover types (with or without Glycine max. The 16S rDNA and 18S rDNA fragments were amplified to analyze the functional diversity of fungi and bacteria. Results showed that rhizosphere microbial biomass and community structure were significantly affected by drought, but effects differed between fungi and bacteria. Drought adaptation of fungi was found to be easier than that of bacteria. The diversity of fungi was less affected by drought than that of bacteria, evidenced by their higher diversity. Severe drought reduced soil microbial functional diversity and restrained the metabolic activity. Elevated CO2 alone, in the absence of crops (bare soil, did not enhance the metabolic activity of soil microorganisms. Generally, due to the co-functioning of plant and soil microorganisms in water and nutrient use, plants have major impacts on the soil microbial community, leading to atmospheric CO2 enrichment, but cannot significantly reduce the impacts of drought on soil microorganisms.

  18. Phylogenetically diverse macrophyte community promotes species diversity of mobile epi-benthic invertebrates

    Science.gov (United States)

    Nakamoto, Kenta; Hayakawa, Jun; Kawamura, Tomohiko; Kodama, Masafumi; Yamada, Hideaki; Kitagawa, Takashi; Watanabe, Yoshiro

    2018-07-01

    Various aspects of plant diversity such as species diversity and phylogenetic diversity enhance the species diversity of associated animals in terrestrial systems. In marine systems, however, the effects of macrophyte diversity on the species diversity of associated animals have received little attention. Here, we sampled in a subtropical seagrass-seaweed mixed bed to elucidate the effect of the macrophyte phylogenetic diversity based on the taxonomic relatedness as well as the macrophyte species diversity on species diversity of mobile epi-benthic invertebrates. Using regression analyses for each macrophyte parameter as well as multiple regression analyses, we found that the macrophyte phylogenetic diversity (taxonomic diversity index: Delta) positively influenced the invertebrate species richness and diversity index (H‧). Although the macrophyte species richness and H‧ also positively influenced the invertebrate species richness, the best fit model for invertebrate species richness did not include them, suggesting that the macrophyte species diversity indirectly influenced invertebrate species diversity. Possible explanations of the effects of macrophyte Delta on the invertebrate species diversity were the niche complementarity effect and the selection effect. This is the first study which demonstrates that macrophyte phylogenetic diversity has a strong effect on the species diversity of mobile epi-benthic invertebrates.

  19. Bacterial community structure and diversity responses to the direct revegetation of an artisanal zinc smelting slag after 5 years.

    Science.gov (United States)

    Luo, Youfa; Wu, Yonggui; Wang, Hu; Xing, Rongrong; Zheng, Zhilin; Qiu, Jing; Yang, Lian

    2018-05-01

    This comparative field study examined the responses of bacterial community structure and diversity to the revegetation of zinc (Zn) smelting waste slag with eight plant species after 5 years. The microbial community structure of waste slag with and without vegetation was evaluated using high-throughput sequencing. The physiochemical properties of Zn smelting slag after revegetation with eight plant rhizospheres for 5 years were improved compared to those of bulk slag. Revegetation significantly increased the microbial community diversity in plant rhizospheres, and at the phylum level, Proteobacteria, Acidobacteria, and Bacteroidetes were notably more abundant in rhizosphere slags than those in bulk waste slag. Additionally, revegetation increased the relative abundance of plant growth-promoting rhizobacteria such as Flavobacterium, Streptomyces, and Arthrobacter as well as symbiotic N 2 fixers such as Bradyrhizobium. Three dominant native plant species (Arundo donax, Broussonetia papyrifera, and Robinia pseudoacacia) greatly increased the quality of the rhizosphere slags. Canonical correspondence analysis showed that the differences in bacterial community structure between the bulk and rhizosphere slags were explained by slag properties, i.e., pH, available copper (Cu) and lead (Pb), moisture, available nitrogen (N), phosphorus (P), and potassium (K), and organic matter (OM); however, available Zn and cadmium (Cd) contents were the slag parameters that best explained the differences between the rhizosphere communities of the eight plant species. The results suggested that revegetation plays an important role in enhancing bacterial community abundance and diversity in rhizosphere slags and that revegetation may also regulate microbiological properties and diversity mainly through changes in heavy metal bioavailability and physiochemical slag characteristics.

  20. Variation of Bacterial Community Diversity in Rhizosphere Soil of Sole-Cropped versus Intercropped Wheat Field after Harvest.

    Directory of Open Access Journals (Sweden)

    Zhenping Yang

    Full Text Available As the major crops in north China, spring crops are usually planted from April through May every spring and harvested in fall. Wheat is also a very common crop traditionally planted in fall or spring and harvested in summer year by year. This continuous cropping system exhibited the disadvantages of reducing the fertility of soil through decreasing microbial diversity. Thus, management of microbial diversity in the rhizosphere plays a vital role in sustainable crop production. In this study, ten common spring crops in north China were chosen sole-cropped and four were chosen intercropped with peanut in wheat fields after harvest. Denaturing gradient gel electrophoresis (DGGE and DNA sequencing of one 16S rDNA fragment were used to analyze the bacterial diversity and species identification. DGGE profiles showed the bacterial community diversity in rhizosphere soil samples varied among various crops under different cropping systems, more diverse under intercropping system than under sole-cropping. Some intercropping-specific bands in DGGE profiles suggested that several bacterial species were stimulated by intercropping systems specifically. Furthermore, the identification of these dominant and functional bacteria by DNA sequencing indicated that intercropping systems are more beneficial to improve soil fertility. Compared to intercropping systems, we also observed changes in microbial community of rhizosphere soil under sole-crops. The rhizosphere bacterial community structure in spring crops showed a strong crop species-specific pattern. More importantly, Empedobacter brevis, a typical plant pathogen, was only found in the carrot rhizosphere, suggesting carrot should be sown prudently. In conclusion, our study demonstrated that crop species and cropping systems had significant effects on bacterial community diversity in the rhizosphere soils. We strongly suggest sorghum, glutinous millet and buckwheat could be taken into account as intercropping

  1. Dominance and Diversity of Bird Community in Floodplain Forest Ecosystem

    Directory of Open Access Journals (Sweden)

    Karel Poprach

    2015-01-01

    Full Text Available The paper is aimed to assessment of diversity and structure of bird community in floodplain forest ecosystem. Authors present results of analyses data on bird communities obtained at two transects in the Litovelské Pomoraví Protected Landscape Area (Czech Republic in the period 1998–2012. Research of bird communities was carried out using the point-count method. The article deals with qualitative and quantitative representation of breeding bird species, including their relation to habitat type (closed floodplain forest, ecotone. Altogether 63 breeding species were recorded at the Vrapač transect and 67 at the Litovelské luhy transect, respectively. To be able to detect all recorded species, 11 out of 14 years of monitoring were needed at the Vrapač transect and all 8 years of monitoring at the Litovelské luhy transect, respectively. Authors show that the values in dominant bird species change significantly among the particular census dates within one season, mainly with respect to their activity and detectability. Results are discussed in the frame of sustainable forest management in floodplain forest ecosystems. The presented article can promote to discussion aimed to management strategy for floodplain forest ecosystems, which ranks among natural habitat types of Community interest protected under the Natura 2000 European network.

  2. 75 FR 32798 - Directorate for Management; DHS Diversity Forum: Building a Community for Women in the Federal...

    Science.gov (United States)

    2010-06-09

    ... Diversity Forum: Building a Community for Women in the Federal Government AGENCY: Directorate for Management... Department of Homeland Security (DHS) Office of the Chief Human Capital Officer will host a DHS Diversity... identify barriers and solutions for women in the workplace. The event will feature panel and roundtable...

  3. User's manual for the National Water-Quality Assessment Program Invertebrate Data Analysis System (IDAS) software, version 5

    Science.gov (United States)

    Cuffney, Thomas F.; Brightbill, Robin A.

    2011-01-01

    The Invertebrate Data Analysis System (IDAS) software was developed to provide an accurate, consistent, and efficient mechanism for analyzing invertebrate data collected as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. The IDAS software is a stand-alone program for personal computers that run Microsoft Windows(Registered). It allows users to read data downloaded from the NAWQA Program Biological Transactional Database (Bio-TDB) or to import data from other sources either as Microsoft Excel(Registered) or Microsoft Access(Registered) files. The program consists of five modules: Edit Data, Data Preparation, Calculate Community Metrics, Calculate Diversities and Similarities, and Data Export. The Edit Data module allows the user to subset data on the basis of taxonomy or sample type, extract a random subsample of data, combine or delete data, summarize distributions, resolve ambiguous taxa (see glossary) and conditional/provisional taxa, import non-NAWQA data, and maintain and create files of invertebrate attributes that are used in the calculation of invertebrate metrics. The Data Preparation module allows the user to select the type(s) of sample(s) to process, calculate densities, delete taxa on the basis of laboratory processing notes, delete pupae or terrestrial adults, combine lifestages or keep them separate, select a lowest taxonomic level for analysis, delete rare taxa on the basis of the number of sites where a taxon occurs and (or) the abundance of a taxon in a sample, and resolve taxonomic ambiguities by one of four methods. The Calculate Community Metrics module allows the user to calculate 184 community metrics, including metrics based on organism tolerances, functional feeding groups, and behavior. The Calculate Diversities and Similarities module allows the user to calculate nine diversity and eight similarity indices. The Data Export module allows the user to export data to other software packages (CANOCO, Primer

  4. Bacterial communities associated with Shinkaia crosnieri from the Iheya North, Okinawa Trough: Microbial diversity and metabolic potentials

    Science.gov (United States)

    Zhang, Jian; Zeng, Zhi-gang; Chen, Shuai; Sun, Li

    2018-04-01

    Shinkaia crosnieri is a galatheid crab endemic to the deep-sea hydrothermal systems in the Okinawa Trough. In this study, we systematically analyzed and compared the diversity and metabolic potentials of the microbial communities in different tissues (setae, gill, and intestine) of S. crosnieri by high-throughput sequencing technology and quantitative real-time polymerase chain reaction. Sequence analysis based on the V3-V4 regions of the 16S rRNA gene obtained 408,079 taxon tags, which covered 15 phyla, 22 classes, 32 orders, 42 families, and 25 genera. Overall, the microbial communities in all tissues were dominated by Epsilonproteobacteria and Gammaproteobacteria, of which Epsilonproteobacteria was the largest class and accounted for 85.24% of the taxon tags. In addition, 20 classes of bacteria were discovered for the first time to be associated with S. crosnieri and no archaea were detected. Comparative analysis showed that (i) bacteria from different tissues fell into different groups by β-diversity analysis, (ii) bacterial communities in intestine were similar to that in gill and much more diverse than that in setae, and the sulfur-oxidizing genus Sulfurovum was markedly enriched in intestine and gill. Furthermore, bacteria potentially involved in methane, nitrogen, and metal metabolisms were detected in all samples. The key genes of aprA/dsrA and pmoA involved in sulfate reducing and methane oxidization, respectively, were detected in the gill and gut communities for the first time, and pmoA was significantly more abundant in gill and setae than in intestine. These results provide the first comparative and relatively complete picture of the diversity and metabolic potentials of the bacteria in different tissues of S. crosnieri. These results also indicate that the composition of the microbial communities in hydrothermal fauna changes with time, suggesting the importance of environmental influence.

  5. Medicinal, Aromatic and Cosmetic (MAC) plants for community health and bio-cultural diversity conservation in Bali, Indonesia

    NARCIS (Netherlands)

    Leurs, Liesbeth Nathalie

    2010-01-01

    The general aim of this ethno-botanical study is to document, describe and analyse the Balinese community members’ knowledge, belief and practices with regard to medicinal, aromatic and cosmetic (MAC) plants in relation to community health and bio-cultural diversity conservation of MAC plants. This

  6. Species diversity of plant communities from territories with natural origin radionuclides contamination

    Energy Technology Data Exchange (ETDEWEB)

    Kaneva, A.V.; Belykh, E.S.; Maystrenko, T.A.; Grusdev, B.I.; Zainullin, V.G.; Vakhrusheva, O.M. [Institute of Biology, Komi Scientific Center, Ural Division of RAS, Syktyvkar, 167982 (Russian Federation); Oughton, D. [Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Aas (Norway)

    2014-07-01

    Since plants dominate every landscape, the impact of any environmental stressor on plants can directly affect the structure and function of an ecosystem, resulting in decreased primary productivity and degradation of wildlife habitat. The investigation goal of the present research was to study how vascular plant species' composition at a former radium mining site could be related to i) soil contamination with heavy metals and uranium and thorium decay chain radionuclides and ii) soil agrochemical properties. Between the 1930's and 1950's, the commercial extraction of radium, storage of the uranium mill tailings and radium production wastes, together with deactivation of the site with a mixture of sand and gravel completely destroyed plant communities in the vicinity of Vodny settlement (Komi Republic, Russia). The plant cover recovery started more than 60 years ago, and resulted in overgrowing with common grassland plant species. Three meadow sites were investigated, one with low contamination (on the territory of former radium production plant), one with high contamination (waste storage cell) and a reference sites out of the radiochemical plant zone of influence, but with similar natural conditions. Geo-botanical descriptions revealed 134 vascular plant species from 34 families in the meadow communities studied. The greatest richness was seen for Poaceae, Asteraceae, Rosaceae and Fabaceae families; others had 1-5 species. The highest richness in diversity was seen at reference sites with 95 vascular plant species. 87 species were registered on low contaminated sites and 75 species on high contaminated. Perennial herbs were the dominant life form on all the studied meadow communities. Arboreal species expansion in vegetation was noted at both experimental and reference sites. Shannon index calculations indicated a significant (p<0.05) decrease in species diversity on sample areas of the highly contaminated radioactive waste storage cell. Mean values

  7. Ceiling effect of online user interests for the movies

    Science.gov (United States)

    Ni, Jing; Zhang, Yi-Lu; Hu, Zhao-Long; Song, Wen-Jun; Hou, Lei; Guo, Qiang; Liu, Jian-Guo

    2014-05-01

    Online users' collective interests play an important role for analyzing the online social networks and personalized recommendations. In this paper, we introduce the information entropy to measure the diversity of the user interests. We empirically analyze the information entropy of the objects selected by the users with the same degree in both the MovieLens and Netflix datasets. The results show that as the user degree increases, the entropy increases from the lowest value at first to the highest value and then begins to fall, which indicates that the interests of the small-degree and large-degree users are more centralized, while the interests of normal users are more diverse. Furthermore, a null model is proposed to compare with the empirical results. In a null model, we keep the number of users and objects as well as the user degrees unchangeable, but the selection behaviors are totally random in both datasets. Results show that the diversity of the majority of users in the real datasets is higher than that the random case, with the exception of the diversity of only a fraction of small-degree users. That may because new users just like popular objects, while with the increase of the user experiences, they quickly become users of broad interests. Therefore, small-degree users' interests are much easier to predict than the other users', which may shed some light for the cold-start problem.

  8. Functional Gene Diversity and Metabolic Potential of the Microbial Community in an Estuary-Shelf Environment

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2017-06-01

    Full Text Available Microbes play crucial roles in various biogeochemical processes in the ocean, including carbon (C, nitrogen (N, and phosphorus (P cycling. Functional gene diversity and the structure of the microbial community determines its metabolic potential and therefore its ecological function in the marine ecosystem. However, little is known about the functional gene composition and metabolic potential of bacterioplankton in estuary areas. The East China Sea (ECS is a dynamic marginal ecosystem in the western Pacific Ocean that is mainly affected by input from the Changjiang River and the Kuroshio Current. Here, using a high-throughput functional gene microarray (GeoChip, we analyzed the functional gene diversity, composition, structure, and metabolic potential of microbial assemblages in different ECS water masses. Four water masses determined by temperature and salinity relationship showed different patterns of functional gene diversity and composition. Generally, functional gene diversity [Shannon–Weaner’s H and reciprocal of Simpson’s 1/(1-D] in the surface water masses was higher than that in the bottom water masses. The different presence and proportion of functional genes involved in C, N, and P cycling among the bacteria of the different water masses showed different metabolic preferences of the microbial populations in the ECS. Genes involved in starch metabolism (amyA and nplT showed higher proportion in microbial communities of the surface water masses than of the bottom water masses. In contrast, a higher proportion of genes involved in chitin degradation was observed in microorganisms of the bottom water masses. Moreover, we found a higher proportion of nitrogen fixation (nifH, transformation of hydroxylamine to nitrite (hao and ammonification (gdh genes in the microbial communities of the bottom water masses compared with those of the surface water masses. The spatial variation of microbial functional genes was significantly correlated

  9. Mature fine tailings from oil sands processing harbour diverse methanogenic communities

    Energy Technology Data Exchange (ETDEWEB)

    Penner, T.J.; Foght, J.M. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences

    2010-06-15

    Syncrude's bitumen extraction process produces a fine tailings slurry consisting of water, sand, fines, residual bitumen and naphtha diluent. Following rapid settling of the sand fraction, the tailings are stored in large settling ponds to form a thick mature fine tailings (MFT). This paper discussed the potential benefits of methane production on management of the settling basins. Enhanced methanogenesis accelerates densification and improves the rheological properties of MFT. In this study molecular techniques were used to characterize the methanogenic communities in uncultivated MFT samples to determine the diversity present in the Mildred Lake Settling Basin (MLSB) and West In-Pit tailings deposit. The flux of methane is currently estimated at about 40 million L/day at the MLSB. Clone libraries of amplified archaeal and bacterial 16S rRNA genes were created in order to analyze the methanogenic consortia in MFT samples from depth profiles in the 2 tailings deposits. The archaeal sequences, whose closest matches were primarily cultivated methanogens, were comparable within and between basins and were mostly affiliated with acetoclastic Methanosaeta spp. However, bacterial clone libraries were diverse, with most sequences relating to Proteobacteria, including some presumptive nitrate-, iron-, or sulfate-reducing, hydrocarbon-degrading genera. The study showed that MFT consists of a diverse community of prokaryotes that may be responsible for producing methane from substrates indigenous to the MFT. These findings contribute to a better understanding of the biogenesis of methane and densification of MFT in oil sands tailings deposits. The results from this study will help determine strategies to control and exploit microbial activities in these large systems and improve the understanding of methanogenic environments. 43 refs., 2 tabs., 3 figs.

  10. What is the role of culture, diversity, and community engagement in transdisciplinary translational science?

    Science.gov (United States)

    Graham, Phillip W; Kim, Mimi M; Clinton-Sherrod, A Monique; Yaros, Anna; Richmond, Alan N; Jackson, Melvin; Corbie-Smith, Giselle

    2016-03-01

    Concepts of culture and diversity are necessary considerations in the scientific application of theory generation and developmental processes of preventive interventions; yet, culture and/or diversity are often overlooked until later stages (e.g., adaptation [T3] and dissemination [T4]) of the translational science process. Here, we present a conceptual framework focused on the seamless incorporation of culture and diversity throughout the various stages of the translational science process (T1-T5). Informed by a community-engaged research approach, this framework guides integration of cultural and diversity considerations at each phase with emphasis on the importance and value of "citizen scientists" being research partners to promote ecological validity. The integrated partnership covers the first phase of intervention development through final phases that ultimately facilitate more global, universal translation of changes in attitudes, norms, and systems. Our comprehensive model for incorporating culture and diversity into translational research provides a basis for further discussion and translational science development.

  11. Microbial community diversity in the gut of the South American termite Cornitermes cumulans (Isoptera: Termitidae).

    Science.gov (United States)

    Grieco, Maria Angela B; Cavalcante, Janaina J V; Cardoso, Alexander M; Vieira, Ricardo P; Machado, Ednildo A; Clementino, Maysa M; Medeiros, Marcelo N; Albano, Rodolpho M; Garcia, Eloi S; de Souza, Wanderley; Constantino, Reginaldo; Martins, Orlando B

    2013-01-01

    Termites inhabit tropical and subtropical areas where they contribute to structure and composition of soils by efficiently degrading biomass with aid of resident gut microbiota. In this study, culture-independent molecular analysis was performed based on bacterial and archaeal 16S rRNA clone libraries to describe the gut microbial communities within Cornitermes cumulans, a South American litter-feeding termite. Our data reveal extensive bacterial diversity, mainly composed of organisms from the phyla Spirochaetes, Bacteroidetes, Firmicutes, Actinobacteria, and Fibrobacteres. In contrast, a low diversity of archaeal 16S rRNA sequences was found, comprising mainly members of the Crenarchaeota phylum. The diversity of archaeal methanogens was further analyzed by sequencing clones from a library for the mcrA gene, which encodes the enzyme methyl coenzyme reductase, responsible for catalyzing the last step in methane production, methane being an important greenhouse gas. The mcrA sequences were diverse and divided phylogenetically into three clades related to uncultured environmental archaea and methanogens found in different termite species. C. cumulans is a litter-feeding, mound-building termite considered a keystone species in natural ecosystems and also a pest in agriculture. Here, we describe the archaeal and bacterial communities within this termite, revealing for the first time its intriguing microbiota.

  12. Impact of transgenic wheat with wheat yellow mosaic virus resistance on microbial community diversity and enzyme activity in rhizosphere soil.

    Science.gov (United States)

    Wu, Jirong; Yu, Mingzheng; Xu, Jianhong; Du, Juan; Ji, Fang; Dong, Fei; Li, Xinhai; Shi, Jianrong

    2014-01-01

    The transgenic wheat line N12-1 containing the WYMV-Nib8 gene was obtained previously through particle bombardment, and it can effectively control the wheat yellow mosaic virus (WYMV) disease transmitted by Polymyxa graminis at turngreen stage. Due to insertion of an exogenous gene, the transcriptome of wheat may be altered and affect root exudates. Thus, it is important to investigate the potential environmental risk of transgenic wheat before commercial release because of potential undesirable ecological side effects. Our 2-year study at two different experimental locations was performed to analyze the impact of transgenic wheat N12-1 on bacterial and fungal community diversity in rhizosphere soil using polymerase chain reaction-denaturing gel gradient electrophoresis (PCR-DGGE) at four growth stages (seeding stage, turngreen stage, grain-filling stage, and maturing stage). We also explored the activities of urease, sucrase and dehydrogenase in rhizosphere soil. The results showed that there was little difference in bacterial and fungal community diversity in rhizosphere soil between N12-1 and its recipient Y158 by comparing Shannon's, Simpson's diversity index and evenness (except at one or two growth stages). Regarding enzyme activity, only one significant difference was found during the maturing stage at Xinxiang in 2011 for dehydrogenase. Significant growth stage variation was observed during 2 years at two experimental locations for both soil microbial community diversity and enzyme activity. Analysis of bands from the gel for fungal community diversity showed that the majority of fungi were uncultured. The results of this study suggested that virus-resistant transgenic wheat had no adverse impact on microbial community diversity and enzyme activity in rhizosphere soil during 2 continuous years at two different experimental locations. This study provides a theoretical basis for environmental impact monitoring of transgenic wheat when the introduced gene is

  13. Impact of transgenic wheat with wheat yellow mosaic virus resistance on microbial community diversity and enzyme activity in rhizosphere soil.

    Directory of Open Access Journals (Sweden)

    Jirong Wu

    Full Text Available The transgenic wheat line N12-1 containing the WYMV-Nib8 gene was obtained previously through particle bombardment, and it can effectively control the wheat yellow mosaic virus (WYMV disease transmitted by Polymyxa graminis at turngreen stage. Due to insertion of an exogenous gene, the transcriptome of wheat may be altered and affect root exudates. Thus, it is important to investigate the potential environmental risk of transgenic wheat before commercial release because of potential undesirable ecological side effects. Our 2-year study at two different experimental locations was performed to analyze the impact of transgenic wheat N12-1 on bacterial and fungal community diversity in rhizosphere soil using polymerase chain reaction-denaturing gel gradient electrophoresis (PCR-DGGE at four growth stages (seeding stage, turngreen stage, grain-filling stage, and maturing stage. We also explored the activities of urease, sucrase and dehydrogenase in rhizosphere soil. The results showed that there was little difference in bacterial and fungal community diversity in rhizosphere soil between N12-1 and its recipient Y158 by comparing Shannon's, Simpson's diversity index and evenness (except at one or two growth stages. Regarding enzyme activity, only one significant difference was found during the maturing stage at Xinxiang in 2011 for dehydrogenase. Significant growth stage variation was observed during 2 years at two experimental locations for both soil microbial community diversity and enzyme activity. Analysis of bands from the gel for fungal community diversity showed that the majority of fungi were uncultured. The results of this study suggested that virus-resistant transgenic wheat had no adverse impact on microbial community diversity and enzyme activity in rhizosphere soil during 2 continuous years at two different experimental locations. This study provides a theoretical basis for environmental impact monitoring of transgenic wheat when the

  14. Ciliate diversity, community structure, and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica.

    Science.gov (United States)

    Xu, Yuan; Vick-Majors, Trista; Morgan-Kiss, Rachael; Priscu, John C; Amaral-Zettler, Linda

    2014-10-01

    We report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and March 2008). We tested hypotheses on the relationship between species richness and environmental conditions including environmental extremes, nutrient status, and day length. On the basis of the unique environment that exists in these high-latitude lakes, we expected that novel taxa would be present. Alpha diversity analyses showed that extreme conditions-that is, high salinity, low oxygen, and extreme changes in day length-did not impact ciliate richness; however, ciliate richness was 30% higher in samples with higher dissolved organic matter. Beta diversity analyses revealed that ciliate communities clustered by dissolved oxygen, depth, and salinity, but not by season (i.e., day length). The permutational analysis of variance test indicated that depth, dissolved oxygen, and salinity had significant influences on the ciliate community for the abundance matrices of resampled data, while lake and season were not significant. This result suggests that the vertical trends in dissolved oxygen concentration and salinity may play a critical role in structuring ciliate communities. A PCR-based strategy capitalizing on divergent eukaryotic V9 hypervariable region ribosomal RNA gene targets unveiled two new genera in these lakes. A novel taxon belonging to an unknown class most closely related to Cryptocaryon irritans was also inferred from separate gene phylogenies. © 2014 Marine Biological Laboratory.

  15. Drivers of cyanobacterial diversity and community composition in mangrove soils in south-east Brazil.

    Science.gov (United States)

    Rigonato, Janaina; Kent, Angela D; Alvarenga, Danillo O; Andreote, Fernando D; Beirigo, Raphael M; Vidal-Torrado, Pablo; Fiore, Marli F

    2013-04-01

    Cyanobacteria act as primary producers of carbon and nitrogen in nutrient-poor ecosystems such as mangroves. This important group of microorganisms plays a critical role in sustaining the productivity of mangrove ecosystems, but the structure and function of cyanobacteria assemblages can be perturbed by anthropogenic influences. The aim of this work was to assess the community structure and ecological drivers that influence the cyanobacterial community harboured in two Brazilian mangrove soils, and examine the long-term effects of oil contamination on these keystone species. Community fingerprinting results showed that, although cyanobacterial communities are distinct between the two mangroves, the structure and diversity of the assemblages exhibit similar responses to environmental gradients. In each ecosystem, cyanobacteria occupying near-shore areas were similar in composition, indicating importance of marine influences for structuring the community. Analysis of 16S rRNA sequences revealed the presence of diverse cyanobacterial communities in mangrove sediments, with clear differences among mangrove habitats along a transect from shore to forest. While near-shore sites in both mangroves were mainly occupied by Prochlorococcus and Synechococcus genera, sequences retrieved from other mangrove niches were mainly affiliated with uncultured cyanobacterial 16S rRNA. The most intriguing finding was the large number of potentially novel cyanobacteria 16S rRNA sequences obtained from a previously oil-contaminated site. The abundance of cyanobacterial 16S rRNA sequences observed in sites with a history of oil contamination was significantly lower than in the unimpacted areas. This study emphasized the role of environmental drivers in determining the structure of cyanobacterial communities in mangrove soils, and suggests that anthropogenic impacts may also act as ecological filters that select cyanobacterial taxa. These results are an important contribution to our

  16. Profile of tobacco users amongst treatment seekers: A comparison between clinic and community sample

    Directory of Open Access Journals (Sweden)

    Savita Malhotra

    2017-01-01

    Full Text Available Background and objectives: Despite the huge burden of tobacco use or addiction, there has been a glaring scarcity of resources to tackle the problem. Although some of the tobacco users want to quit, very few have the opportunity to seek help from available treatment facilities. The study aimed to find out the profile of treatment seekers from clinic and community programs and also to compare the two groups. Method: This is a cross sectional, retrospective study of subjects enrolled in the clinic and various community outreach programs of a Tobacco Cessation Centre from the year 2002-2011. Modified intake form developed by the WHO was administered to the subjects. Results: Significant difference was found between the two groups with regard to the age of treatment seeking, education and socio economic status. Older subjects reported in greater numbers to the clinic, whereas younger subjects belonged to the community group. Community group had lower level of education, belonged to lower or upper lower socio economic status whereas clinic group had higher level of education and were from the middle or upper socio economic status. Curiosity (Z score = 3.2,P = 0.001 played a significant role in initiating the use in clinic group whereas role model (Z score = 5.1, P = <0.0001 and low self esteem (Z score = 2.0, P = 0.023 were significantly associated with community sample. Presence of medical complications (Z score = 12.5, P = <0.0001, awareness of physical harm of nicotine (Z score = 5.0, P = <0.0001 and awareness of addiction was significantly more in the clinic group. Interpretation and Conclusions: The difference in the socio-demographic and clinical profile of tobacco users in these two treatment groups is noteworthy, and is expected to offer useful information for the clinicians and as well as for the policy makers.

  17. Characterisation of the gill mucosal bacterial communities of four butterflyfish species: a reservoir of bacterial diversity in coral reef ecosystems.

    Science.gov (United States)

    Reverter, Miriam; Sasal, Pierre; Tapissier-Bontemps, N; Lecchini, D; Suzuki, M

    2017-06-01

    While recent studies have suggested that fish mucus microbiota play an important role in homeostasis and prevention of infections, very few studies have investigated the bacterial communities of gill mucus. We characterised the gill mucus bacterial communities of four butterflyfish species and although the bacterial diversity of gill mucus varied significantly between species, Shannon diversities were high (H = 3.7-5.7) in all species. Microbiota composition differed between butterflyfishes, with Chaetodon lunulatus and C. ornatissimus having the most similar bacterial communities, which differed significantly from C. vagabundus and C. reticulatus. The core bacterial community of all species consisted of mainly Proteobacteria followed by Actinobacteria and Firmicutes. Chaetodonlunulatus and C. ornatissimus bacterial communities were mostly dominated by Gammaproteobacteria with Vibrio as the most abundant genus. Chaetodonvagabundus and C. reticulatus presented similar abundances of Gammaproteobacteria and Alphaproteobacteria, which were well represented by Acinetobacter and Paracoccus, respectively. In conclusion, our results indicate that different fish species present specific bacterial assemblages. Finally, as mucus layers are nutrient hotspots for heterotrophic bacteria living in oligotrophic environments, such as coral reef waters, the high bacterial diversity found in butterflyfish gill mucus might indicate external fish mucus surfaces act as a reservoir of coral reef bacterial diversity. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Soil fungal community and fuctional diversity assessments of agroecosystems in the Southern High Plains

    Science.gov (United States)

    Soil fungi perform a variety of ecosystem functions that are crucial to maintaining agroecosystem sustainability including aggregate stability and soil carbon storage. The purpose of this study was to compare soil fungal communities and functional diversity in integrated crop and livestock (ICL) sy...

  19. Community analysis of the abundance and diversity of biting midge species (Diptera: Ceratopogonidae) in three European countries at different latitudes.

    Science.gov (United States)

    Möhlmann, Tim W R; Wennergren, Uno; Tälle, Malin; Favia, Guido; Damiani, Claudia; Bracchetti, Luca; Takken, Willem; Koenraadt, Constantianus J M

    2018-03-27

    The outbreaks of bluetongue and Schmallenberg disease in Europe have increased efforts to understand the ecology of Culicoides biting midges and their role in pathogen transmission. However, most studies have focused on a specific habitat, region, or country. To facilitate wider comparisons, and to obtain a better understanding of the spread of disease through Europe, the present study focused on monitoring biting midge species diversity in three different habitat types and three countries across Europe. Biting midges were trapped using Onderstepoort Veterinary Institute light traps at a total of 27 locations in Sweden, the Netherlands and Italy, comprising farm, peri-urban and wetland habitats. From July 2014 to June 2015 all locations were sampled monthly, except for during the winter months. Trapped midges were counted and identified morphologically. Indices on species richness, evenness and diversity were calculated. Community compositions were analysed using non-metric multidimensional scaling (NMDS) techniques. A total of 50,085 female midges were trapped during 442 collection nights. More than 88% of these belonged to the Obsoletus group. The highest midge diversity was found in Sweden, while species richness was highest in the Netherlands, and most specimens were trapped in Italy. For habitats within countries, diversity of the trapped midges was lowest for farms in all countries. Differences in biting midge species communities were more distinct across the three countries than the three habitat types. A core midge community could be identified, in which the Obsoletus group was the most abundant. Variations in vector communities across countries imply different patterns of disease spread throughout Europe. How specific species and their associated communities affect disease risk is still unclear. Our results emphasize the importance of midge diversity data at community level, how this differs across large geographic range within Europe, and its implications

  20. Wider-community Segregation and the Effect of Neighbourhood Ethnic Diversity on Social Capital: An Investigation into Intra-Neighbourhood Trust in Great Britain and London.

    Science.gov (United States)

    Laurence, James

    2017-10-01

    Extensive research has demonstrated that neighbourhood ethnic diversity is negatively associated with intra-neighbourhood social capital. This study explores the role of segregation and integration in this relationship. To do so it applies three-level hierarchical linear models to two sets of data from across Great Britain and within London, and examines how segregation across the wider-community in which a neighbourhood is nested impacts trust amongst neighbours. This study replicates the increasingly ubiquitous finding that neighbourhood diversity is negatively associated with neighbour-trust. However, we demonstrate that this relationship is highly dependent on the level of segregation across the wider-community in which a neighbourhood is nested. Increasing neighbourhood diversity only negatively impacts neighbour-trust when nested in more segregated wider-communities. Individuals living in diverse neighbourhoods nested within integrated wider-communities experience no trust-penalty. These findings show that segregation plays a critical role in the neighbourhood diversity/trust relationship, and that its absence from the literature biases our understanding of how ethnic diversity affects social cohesion.

  1. The power of ground user in recommender systems.

    Directory of Open Access Journals (Sweden)

    Yanbo Zhou

    Full Text Available Accuracy and diversity are two important aspects to evaluate the performance of recommender systems. Two diffusion-based methods were proposed respectively inspired by the mass diffusion (MD and heat conduction (HC processes on networks. It has been pointed out that MD has high recommendation accuracy yet low diversity, while HC succeeds in seeking out novel or niche items but with relatively low accuracy. The accuracy-diversity dilemma is a long-term challenge in recommender systems. To solve this problem, we introduced a background temperature by adding a ground user who connects to all the items in the user-item bipartite network. Performing the HC algorithm on the network with ground user (GHC, it showed that the accuracy can be largely improved while keeping the diversity. Furthermore, we proposed a weighted form of the ground user (WGHC by assigning some weights to the newly added links between the ground user and the items. By turning the weight as a free parameter, an optimal value subject to the highest accuracy is obtained. Experimental results on three benchmark data sets showed that the WGHC outperforms the state-of-the-art method MD for both accuracy and diversity.

  2. The power of ground user in recommender systems.

    Science.gov (United States)

    Zhou, Yanbo; Lü, Linyuan; Liu, Weiping; Zhang, Jianlin

    2013-01-01

    Accuracy and diversity are two important aspects to evaluate the performance of recommender systems. Two diffusion-based methods were proposed respectively inspired by the mass diffusion (MD) and heat conduction (HC) processes on networks. It has been pointed out that MD has high recommendation accuracy yet low diversity, while HC succeeds in seeking out novel or niche items but with relatively low accuracy. The accuracy-diversity dilemma is a long-term challenge in recommender systems. To solve this problem, we introduced a background temperature by adding a ground user who connects to all the items in the user-item bipartite network. Performing the HC algorithm on the network with ground user (GHC), it showed that the accuracy can be largely improved while keeping the diversity. Furthermore, we proposed a weighted form of the ground user (WGHC) by assigning some weights to the newly added links between the ground user and the items. By turning the weight as a free parameter, an optimal value subject to the highest accuracy is obtained. Experimental results on three benchmark data sets showed that the WGHC outperforms the state-of-the-art method MD for both accuracy and diversity.

  3. Resistance and diversity: cultural narratives of a quilombola community

    Directory of Open Access Journals (Sweden)

    Valdir Pierote Silva

    2016-01-01

    Full Text Available Riacho das Pedras was a remnant quilombo community in the municipality of Rio de Contas (Bahia which lands were flooded after the construction of a dam. The work led to serious impacts on the affected population and to the surrounding environment. We performed a five trajectories study of former residents of this village between 2008 and 2009. Based on the narratives, we sought to map the displacement processes, the establishment in new territories and the group current conditions. Our project was developed based on interviews, literature, ethnographic inspiration field and oral history of life method. This article aims to conduct an analysis focusing on the quilombo cultural manifestations and consequences of these practices in the local context. We believe that despite the diaspora, the community has endured and asserted itself politically through artistic and cultural events. We understand that the quilombo descendants have (recreated specific forms of expression that value them positively. Besides, through these expressions, important cultural variations are accomplished in order to contribute to the expansion of diversity in Rio de Contas.

  4. Reproduction of Amorpha canescens (Fabaceae) and diversity of its bee community in a fragmented landscape.

    Science.gov (United States)

    Slagle, Malinda W; Hendrix, Stephen D

    2009-10-01

    Loss of insect pollinators due to habitat fragmentation often results in negative effects on plant reproduction, but few studies have simultaneously examined variation in the bee community, site characteristics and plant community characteristics to evaluate their relative effects on plant reproduction in a fragmented habitat. We examined the reproduction of a common tallgrass prairie forb, Amorpha canescens (Fabaceae), in large (>40 ha) and small (level characteristics can influence the bee community visiting any one species. Site size, a common predictor of plant reproduction in fragmented habitats did not contribute to any models of fruit set and was only marginally related to bee diversity one year. Andrena quintilis, one of the three oligolectic bee species associated with A. canescens, was abundant at all sites, suggesting it has not been significantly affected by fragmentation. Our results show that the diversity of bees visiting A. canescens is important for maintaining fruit set and that bee visitation is still sufficient for at least some fruit set in all populations, suggesting these small remnants act as floral resource oases for bees in landscapes often dominated by agriculture.

  5. Relative diversity and community structure analysis of rumen protozoa according to T-RFLP and microscopic methods.

    Science.gov (United States)

    Tymensen, Lisa; Barkley, Cindy; McAllister, Tim A

    2012-01-01

    Protozoa are common inhabitants of the rumen where they play roles in host nutrition and methanogenesis. Knowledge of how changes in the composition of protozoa communities affect these processes is limited in part due to a lack of efficient methods for protozoa community analysis. In this study, a terminal-restriction fragment length polymorphism (T-RFLP) assay targeting the 18S rRNA gene was developed for comparative analysis of rumen protozoa communities. Comparison of diversity and structure of protozoa communities from hay-fed versus silage/grain-fed cattle via T-RFLP analysis yielded similar overall results to microscopy analysis. According to both methods, Entodinium spp. were more abundant in the silage/grain-fed cattle and protozoa diversity (as calculated using the Shannon index) was higher for the hay-fed cattle due to greater species evenness. Type B protozoa were more prevalent in the hay-fed cattle, whereas Type A protozoa were more prevalent in the silage/grain-fed cattle. Analysis of similarity (ANOSIM) indicated that the protozoa communities from hay-fed and silage/grain-fed cattle were different, and multivariate analysis indicated that pen mates (i.e., cattle fed the same diet and housed together) tended to have similar protozoa communities types. In summary, we present a T-RFLP method for analyzing rumen protozoa communities which complements traditional microscopy approaches but has the advantage of being amenable to high-throughput. Copyright © 2011. Published by Elsevier B.V.

  6. EPOS Seismology services and their users

    Science.gov (United States)

    Haslinger, Florian; Dupont, Aurelien; Michelini, Alberto; Rietbrock, Andreas; Sleeman, Reinoud; Wiemer, Stefan; Basili, Roberto; Bossu, Rémy; Cakti, Eser; Cotton, Fabrice; Crawford, Wayne; Crowley, Helen; Danciu, Laurentiu; Diaz, Jordi; Garth, Tom; Locati, Mario; Luzi, Lucia; Pitilakis, Kyriazis; Roumelioti, Zafeiria; Strollo, Angelo

    2017-04-01

    The construction of seismological community services for the European Plate Observing System Research Infrastructure (EPOS) is by now well under way. A significant number of services are already operational, largely based on those existing at established institutions or collaborations like ORFEUS, EMSC, AHEAD and EFEHR, and more are being added to be ready for internal validation by late 2017. In this presentation we focus on a number of issues related to the interaction of the community of users with the services provided by the seismological part of the EPOS research infrastructure. How users interact with a service (and how satisfied they are with this interaction) is viewed as one important component of the validation of a service within EPOS, and certainly is key to the uptake of a service and from that also it's attributed value. Within EPOS Seismology, the following aspects of user interaction have already surfaced: - user identification (and potential tracking) versus ease-of-access and openness Requesting users to identify themselves when accessing a service provides various advantages to providers and users (e.g. quantifying & qualifying the service use, customization of services and interfaces, handling access rights and quotas), but may impact the ease of access and also shy away users who don't wish to be identified for whatever reason. - service availability versus cost There is a clear and prominent connection between the availability of a service, both regarding uptime and capacity, and its operational cost (IT systems and personnel), and it is often not clear where to draw the line (and based on which considerations). In connection to that, how to best utilize third-party IT infrastructures (either commercial or public), and what the long-term cost implications of that might be, is equally open. - licensing and attribution The issue of intellectual property and associated licensing policies for data, products and services is only recently gaining

  7. Petroleum-influenced beach sediments of the campeche bank, Mexico: Diversity and bacterial community structure assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rosano-Hernandez, M. C.; Ramirez-Saad, H.; Fernandez-Linares, L.; Xoconostle, B.

    2009-07-01

    In Mexican, either spilled or seeped out petroleum impacts nearly 300 km of the beach between Dos Bocas (Tabasco State) to Champoton town (Campeche State), where between 9 to exceptionally 9 to exceptionally 300 tonnes of oil as tar balls have been measured. This study was focused to explore, for the first time, the bacterial diversity and community structure ({alpha}-diversity)- in a kilometric scale on petroleum influenced sediments of 100 km of sandy beach. (Author)

  8. Petroleum-influenced beach sediments of the campeche bank, Mexico: Diversity and bacterial community structure assessment

    International Nuclear Information System (INIS)

    Rosano-Hernandez, M. C.; Ramirez-Saad, H.; Fernandez-Linares, L.; Xoconostle, B.

    2009-01-01

    In Mexican, either spilled or seeped out petroleum impacts nearly 300 km of the beach between Dos Bocas (Tabasco State) to Champoton town (Campeche State), where between 9 to exceptionally 9 to exceptionally 300 tonnes of oil as tar balls have been measured. This study was focused to explore, for the first time, the bacterial diversity and community structure (α-diversity)- in a kilometric scale on petroleum influenced sediments of 100 km of sandy beach. (Author)

  9. Diversity and community ecology of forest epiphyte testate amoebae from European Russia.

    Science.gov (United States)

    Payne, Richard J; Belyakova, Olga; Mazei, Yuri

    2015-10-01

    Testate amoebae are an abundant group of microorganisms which make a significant contribution to the diversity of protist life. Most of the world's potential habitats for testate amoebae have been barely studied and when such places are investigated they frequently reveal novel communities and species. Here we consider the testate amoeba communities associated with boreal forest epiphytes (mosses and lichens); an environment which we argue has been under-researched. We present a dataset of 165 samples from four regions of western Russia and analyse these data in relation to micro-habitat position and selected environmental data. The testate amoebae of epiphytes are abundant but dominated by ubiquitous species. We show that there are trends toward a lower species richness and test concentration with greater elevation on the trunk and in lichens compared to mosses. There are considerable differences in community composition between sampling regions. Of all measured environmental variables only moisture content showed a significant relationship with testate amoeba community structure. Our data highlight how little is known about testate amoeba communities of this habitat and call for greater research efforts, particularly in less-studied regions and biomes. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. Drivers shaping the diversity and biogeography of total and active bacterial communities in the South China Sea

    Science.gov (United States)

    Zhang, Yao; Zhao, Zihao; Dai, Minhan; Jiao, Nianzhi; Herndl, Gerhard J

    2014-01-01

    To test the hypothesis that different drivers shape the diversity and biogeography of the total and active bacterial community, we examined the bacterial community composition along two transects, one from the inner Pearl River estuary to the open waters of the South China Sea (SCS) and the other from the Luzon Strait to the SCS basin, using 454 pyrosequencing of the 16S rRNA and 16S rRNA gene (V1-3 regions) and thereby characterizing the active and total bacterial community, respectively. The diversity and biogeographic patterns differed substantially between the active and total bacterial communities. Although the composition of both the total and active bacterial community was strongly correlated with environmental factors and weakly correlated with geographic distance, the active bacterial community displayed higher environmental sensitivity than the total community and particularly a greater distance effect largely caused by the active assemblage from deep waters. The 16S rRNA vs. rDNA relationships indicated that the active bacteria were low in relative abundance in the SCS. This might be due to a high competition between active bacterial taxa as indicated by our community network models. Based on these analyses, we speculate that high competition could cause some dispersal limitation of the active bacterial community resulting in a distinct distance-decay relationship. Altogether, our results indicated that the biogeographic distribution of bacteria in the SCS is the result of both environmental control and distance decay. PMID:24684298

  11. Application of Ion Torrent Sequencing to the Assessment of the Effect of Alkali Ballast Water Treatment on Microbial Community Diversity

    Science.gov (United States)

    Fujimoto, Masanori; Moyerbrailean, Gregory A.; Noman, Sifat; Gizicki, Jason P.; Ram, Michal L.; Green, Phyllis A.; Ram, Jeffrey L.

    2014-01-01

    The impact of NaOH as a ballast water treatment (BWT) on microbial community diversity was assessed using the 16S rRNA gene based Ion Torrent sequencing with its new 400 base chemistry. Ballast water samples from a Great Lakes ship were collected from the intake and discharge of both control and NaOH (pH 12) treated tanks and were analyzed in duplicates. One set of duplicates was treated with the membrane-impermeable DNA cross-linking reagent propidium mono-azide (PMA) prior to PCR amplification to differentiate between live and dead microorganisms. Ion Torrent sequencing generated nearly 580,000 reads for 31 bar-coded samples and revealed alterations of the microbial community structure in ballast water that had been treated with NaOH. Rarefaction analysis of the Ion Torrent sequencing data showed that BWT using NaOH significantly decreased microbial community diversity relative to control discharge (pbased principal coordinate analysis (PCoA) plots and UPGMA tree analysis revealed that NaOH-treated ballast water microbial communities differed from both intake communities and control discharge communities. After NaOH treatment, bacteria from the genus Alishewanella became dominant in the NaOH-treated samples, accounting for alkali ballast water treatment in reducing ballast water microbial diversity and demonstrated the application of new Ion Torrent sequencing techniques to microbial community studies. PMID:25222021

  12. Divergence Measures as Diversity Indices

    OpenAIRE

    Abou-Moustafa, Karim T.

    2014-01-01

    Entropy measures of probability distributions are widely used measures in ecology, biology, genetics, and in other fields, to quantify species diversity of a community. Unfortunately, entropy-based diversity indices, or diversity indices for short, suffer from three problems. First, when computing the diversity for samples withdrawn from communities with different structures, diversity indices can easily yield non-comparable and hard to interpret results. Second, diversity indices impose weig...

  13. Diversity and ecological aspects of aquatic insect communities from montane streams in southern Brazil

    Directory of Open Access Journals (Sweden)

    Bruna Marmitt Braun

    2014-06-01

    Full Text Available AIMS: In this study, the diversity of Ephemeroptera, Plecoptera, Trichoptera and Coleoptera communities was surveyed in the Toropi River basin, a watershed localized in a slope region, in southernmost Brazil. The influence of some local abiotic factors on the most common genera was also analyzed. METHODS: Samplings were conducted at 40 sites in 1st-4th order streams, along a short elevation gradient (70-500 m, with a Surber sampler. Water physico-chemical factors, as well as substrate type, were obtained at each site. RESULTS: At all, 5,320 specimens were collected, belonging to 18 families and 52 genera. The caddisflies Austrotinodes and Celaenotrichia, and an undescribed Elmidae, Genus M, are new records for the region. The caddisfly Smicridea was the most frequent genus in the study area. The mayflies Camelobaetidius, Paracloeodes and Americabaetis were influenced by stream order. Smicridea was related to air temperature, while the mayfly Thraulodes was influenced by high levels of electrical conductivity. CONCLUSIONS: The high diversity found in the study area, compared to other Brazilian regions, reflects the environmental heterogeneity in the region. These data show that hydrographic basins in slope areas from extreme Southern Brazil sustain high levels of diversity of aquatic insect communities.

  14. Utilizing Big Data and Twitter to Discover Emergent Online Communities of Cannabis Users

    Directory of Open Access Journals (Sweden)

    Peter Baumgartner

    2017-05-01

    Full Text Available Large shifts in medical, recreational, and illicit cannabis consumption in the United States have implications for personalizing treatment and prevention programs to a wide variety of populations. As such, considerable research has investigated clinical presentations of cannabis users in clinical and population-based samples. Studies leveraging big data, social media, and social network analysis have emerged as a promising mechanism to generate timely insights that can inform treatment and prevention research. This study extends a novel method called stochastic block modeling to derive communities of cannabis consumers as part of a complex social network on Twitter. A set of examples illustrate how this method can ascertain candidate samples of medical, recreational, and illicit cannabis users. Implications for research planning, intervention design, and public health surveillance are discussed.

  15. An Assessment of Urea-Formaldehyde Fertilizer on the Diversity of Bacterial Communities in Onion and Sugar Beet

    OpenAIRE

    Ikeda, Seishi; Suzuki, Keijiro; Kawahara, Makoto; Noshiro, Masao; Takahashi, Naokazu

    2014-01-01

    The impact of a urea-formaldehyde (UF) fertilizer on bacterial diversity in onion bulbs and main roots of sugar beet were examined using a 16S rRNA gene clone library. The UF fertilizer markedly increased bacterial diversity in both plants. The results of principal coordinates analysis (PCoA) revealed that nearly 30% of the variance observed in bacterial diversity in both the onion and sugar beet was attributed to the fertilization conditions and also that the community structures in both pla...

  16. Succession of Bacterial Community Structure and Diversity in Soil along a Chronosequence of Reclamation and Re-Vegetation on Coal Mine Spoils in China

    Science.gov (United States)

    Li, Yuanyuan; Wen, Hongyu; Chen, Longqian; Yin, Tingting

    2014-01-01

    The growing concern about the effectiveness of reclamation strategies has motivated the evaluation of soil properties following reclamation. Recovery of belowground microbial community is important for reclamation success, however, the response of soil bacterial communities to reclamation has not been well understood. In this study, PCR-based 454 pyrosequencing was applied to compare bacterial communities in undisturbed soils with those in reclaimed soils using chronosequences ranging in time following reclamation from 1 to 20 year. Bacteria from the Proteobacteria, Chloroflexi, Actinobacteria, Acidobacteria, Planctomycetes and Bacteroidetes were abundant in all soils, while the composition of predominant phyla differed greatly across all sites. Long-term reclamation strongly affected microbial community structure and diversity. Initial effects of reclamation resulted in significant declines in bacterial diversity indices in younger reclaimed sites (1, 8-year-old) compared to the undisturbed site. However, bacterial diversity indices tended to be higher in older reclaimed sites (15, 20-year-old) as recovery time increased, and were more similar to predisturbance levels nearly 20 years after reclamation. Bacterial communities are highly responsive to soil physicochemical properties (pH, soil organic matter, Total N and P), in terms of both their diversity and community composition. Our results suggest that the response of soil microorganisms to reclamation is likely governed by soil characteristics and, indirectly, by the effects of vegetation restoration. Mixture sowing of gramineae and leguminosae herbage largely promoted soil geochemical conditions and bacterial diversity that recovered to those of undisturbed soil, representing an adequate solution for soil remediation and sustainable utilization for agriculture. These results confirm the positive impacts of reclamation and vegetation restoration on soil microbial diversity and suggest that the most important

  17. [Effect of ground mulch managements on soil bacterial community structure and diversity in the non-irrigated apple orchard in Weibei Loess Plateau].

    Science.gov (United States)

    Chen, Yuexing; Wen, Xiaoxia; Sun, Yulin; Zhang, Junli; Lin, Xiaoli; Liao, Yuncheng

    2015-07-04

    We studied the changes in soil bacterial communities induced by ground mulch managements at different apple growth periods. We adopted the denaturing gradient gel electrophoresis (DGGE) with PCR-amplified 16S rRNA fragments to determine soil bacterial community structure and diversity. Soil bacterial community structure with different ground mulch managements were significantly different. Both the mulch management strategies and apple growth periods affected the predominant groups and their abundance in soil bacterial communities. Grass mulch and cornstalk mulch treatments had higher bacterial diversity and richness than the control at young fruit period and fruit expanding period, whereas film mulch treatment had no significant difference compared with the control. During mature period, bacterial diversity in the control reached its maximum, which may be ascribed to the rapid growth and reproduction of the r-selection bacteria. The clustering and detrended correspondence analysis revealed that differences in soil bacterial communities were closely correlated to apple growth periods and ground mulch managements. Soil samples from the grass mulch and cornstalk mulch treatments clustered together while those mulched with plastic film treatment were similar to the control. The most abundant phylum in soil bacterial community was Proteobacteria followed by Bacteroidetes. Some other phyla were also detected, such as Acidobacteria, Firmicutes, Actinobacteria and Chloroflexi. Mulching with plant (Grass/Cornstalk) had great effects on soil bacterial community structure and enhanced the diversity while film mulch management had no significant effects.

  18. Elevational diversity and distribution of ammonia-oxidizing archaea community in meadow soils on the Tibetan Plateau.

    Science.gov (United States)

    Zhao, Kang; Kong, Weidong; Khan, Ajmal; Liu, Jinbo; Guo, Guangxia; Muhanmmad, Said; Zhang, Xianzhou; Dong, Xiaobin

    2017-09-01

    Unraveling elevational diversity patterns of plants and animals has long been attracting scientific interests. However, whether soil microorganisms exhibit similar elevational patterns remains largely less explored, especially for functional microbial communities, such as ammonia oxidizers. Here, we investigated the diversity and distribution pattern of ammonia-oxidizing archaea (AOA) in meadow soils along an elevation gradient from 4400 m to the grassline at 5100 m on the Tibetan Plateau using terminal restriction fragment length polymorphism (T-RFLP) and sequencing methods by targeting amoA gene. Increasing elevations led to lower soil temperature and pH, but higher nutrients and water content. The results showed that AOA diversity and evenness monotonically increased with elevation, while richness was relatively stable. The increase of diversity and evenness was attributed to the growth inhibition of warm-adapted AOA phylotypes by lower temperature and the growth facilitation of cold-adapted AOA phylotypes by richer nutrients at higher elevations. Low temperature thus played an important role in the AOA growth and niche separation. The AOA community variation was explained by the combined effect of all soil properties (32.6%), and 8.1% of the total variation was individually explained by soil pH. The total AOA abundance decreased, whereas soil potential nitrification rate (PNR) increased with increasing elevations. Soil PNR positively correlated with the abundance of cold-adapted AOA phylotypes. Our findings suggest that low temperature plays an important role in AOA elevational diversity pattern and niche separation, rising the negative effects of warming on AOA diversity and soil nitrification process in the Tibetan region.

  19. Pig Farmers’ Homes Harbor More Diverse Airborne Bacterial Communities Than Pig Stables or Suburban Homes

    Directory of Open Access Journals (Sweden)

    Ditte V. Vestergaard

    2018-05-01

    Full Text Available Airborne bacterial communities are subject to conditions ill-suited to microbial activity and growth. In spite of this, air is an important transfer medium for bacteria, with the bacteria in indoor air having potentially major consequences for the health of a building’s occupants. A major example is the decreased diversity and altered composition of indoor airborne microbial communities as a proposed explanation for the increasing prevalence of asthma and allergies worldwide. Previous research has shown that living on a farm confers protection against development of asthma and allergies, with airborne bacteria suggested as playing a role in this protective effect. However, the composition of this beneficial microbial community has still not been identified. We sampled settled airborne dust using a passive dust sampler from Danish pig stables, associated farmers’ homes, and from suburban homes (267 samples in total and carried out quantitative PCR measurements of bacterial abundance and MiSeq sequencing of the V3–V4 region of bacterial 16S rRNA genes found in these samples. Airborne bacteria had a greater diversity and were significantly more abundant in pig stables and farmers’ homes than suburban homes (Wilcoxon rank sum test P < 0.05. Moreover, bacterial taxa previously suggested to contribute to a protective effect had significantly higher relative and absolute abundance in pig stables and farmers’ homes than in suburban homes (ALDEx2 with P < 0.05, including Firmicutes, Peptostreptococcaceae, Prevotellaceae, Lachnospiraceae, Ruminococcaceae, Ruminiclostridium, and Lactobacillus. Pig stables had significantly lower airborne bacterial diversity than farmers’ homes, and there was no discernable direct transfer of airborne bacteria from stable to home. This study identifies differences in indoor airborne bacterial communities that may be an important component of this putative protective effect, while showing that pig stables

  20. Pig Farmers’ Homes Harbor More Diverse Airborne Bacterial Communities Than Pig Stables or Suburban Homes

    Science.gov (United States)

    Vestergaard, Ditte V.; Holst, Gitte J.; Basinas, Ioannis; Elholm, Grethe; Schlünssen, Vivi; Linneberg, Allan; Šantl-Temkiv, Tina; Finster, Kai; Sigsgaard, Torben; Marshall, Ian P. G.

    2018-01-01

    Airborne bacterial communities are subject to conditions ill-suited to microbial activity and growth. In spite of this, air is an important transfer medium for bacteria, with the bacteria in indoor air having potentially major consequences for the health of a building’s occupants. A major example is the decreased diversity and altered composition of indoor airborne microbial communities as a proposed explanation for the increasing prevalence of asthma and allergies worldwide. Previous research has shown that living on a farm confers protection against development of asthma and allergies, with airborne bacteria suggested as playing a role in this protective effect. However, the composition of this beneficial microbial community has still not been identified. We sampled settled airborne dust using a passive dust sampler from Danish pig stables, associated farmers’ homes, and from suburban homes (267 samples in total) and carried out quantitative PCR measurements of bacterial abundance and MiSeq sequencing of the V3–V4 region of bacterial 16S rRNA genes found in these samples. Airborne bacteria had a greater diversity and were significantly more abundant in pig stables and farmers’ homes than suburban homes (Wilcoxon rank sum test P < 0.05). Moreover, bacterial taxa previously suggested to contribute to a protective effect had significantly higher relative and absolute abundance in pig stables and farmers’ homes than in suburban homes (ALDEx2 with P < 0.05), including Firmicutes, Peptostreptococcaceae, Prevotellaceae, Lachnospiraceae, Ruminococcaceae, Ruminiclostridium, and Lactobacillus. Pig stables had significantly lower airborne bacterial diversity than farmers’ homes, and there was no discernable direct transfer of airborne bacteria from stable to home. This study identifies differences in indoor airborne bacterial communities that may be an important component of this putative protective effect, while showing that pig stables themselves do not appear

  1. Pig Farmers' Homes Harbor More Diverse Airborne Bacterial Communities Than Pig Stables or Suburban Homes.

    Science.gov (United States)

    Vestergaard, Ditte V; Holst, Gitte J; Basinas, Ioannis; Elholm, Grethe; Schlünssen, Vivi; Linneberg, Allan; Šantl-Temkiv, Tina; Finster, Kai; Sigsgaard, Torben; Marshall, Ian P G

    2018-01-01

    Airborne bacterial communities are subject to conditions ill-suited to microbial activity and growth. In spite of this, air is an important transfer medium for bacteria, with the bacteria in indoor air having potentially major consequences for the health of a building's occupants. A major example is the decreased diversity and altered composition of indoor airborne microbial communities as a proposed explanation for the increasing prevalence of asthma and allergies worldwide. Previous research has shown that living on a farm confers protection against development of asthma and allergies, with airborne bacteria suggested as playing a role in this protective effect. However, the composition of this beneficial microbial community has still not been identified. We sampled settled airborne dust using a passive dust sampler from Danish pig stables, associated farmers' homes, and from suburban homes (267 samples in total) and carried out quantitative PCR measurements of bacterial abundance and MiSeq sequencing of the V3-V4 region of bacterial 16S rRNA genes found in these samples. Airborne bacteria had a greater diversity and were significantly more abundant in pig stables and farmers' homes than suburban homes (Wilcoxon rank sum test P < 0.05). Moreover, bacterial taxa previously suggested to contribute to a protective effect had significantly higher relative and absolute abundance in pig stables and farmers' homes than in suburban homes (ALDEx2 with P < 0.05), including Firmicutes, Peptostreptococcaceae, Prevotellaceae, Lachnospiraceae, Ruminococcaceae, Ruminiclostridium , and Lactobacillus . Pig stables had significantly lower airborne bacterial diversity than farmers' homes, and there was no discernable direct transfer of airborne bacteria from stable to home. This study identifies differences in indoor airborne bacterial communities that may be an important component of this putative protective effect, while showing that pig stables themselves do not appear to

  2. Community College Faculty Members' Perceived Multicultural Teaching Competence and Attitudes Regarding Cultural Diversity

    Science.gov (United States)

    Fittz, Mia Web

    2015-01-01

    This study utilized the Survey of Community College Faculty (SCCF), a combined survey of the Multicultural Teaching Scale (MTS) and Pluralism and Diversity Attitude Assessment (PADAA) that framed the research. The MTS assessed self-reported cultural competencies categorized into five dimensions: (a) Content Integration, (b) Knowledge Construction,…

  3. Plant diversity predicts beta but not alpha diversity of soil microbes across grasslands worldwide

    Science.gov (United States)

    Prober, Suzanne M.; Leff, Jonathan W.; Bates, Scott T.; Borer, Elizabeth T.; Firn, Jennifer; Harpole, W. Stanley; Lind, Eric M.; Seabloom, Eric W.; Adler, Peter B.; Bakker, Jonathan D.; Cleland, Elsa E.; DeCrappeo, Nicole; DeLorenze, Elizabeth; Hagenah, Nicole; Hautier, Yann; Hofmockel, Kirsten S.; Kirkman, Kevin P.; Knops, Johannes M. H.; La Pierre, Kimberly J.; MacDougall, Andrew S.; McCulley, Rebecca L.; Mitchell, Charles E.; Risch, Anita C.; Schuetz, Martin; Stevens, Carly J.; Williams, Ryan J.; Fierer, Noah

    2015-01-01

    Aboveground–belowground interactions exert critical controls on the composition and function of terrestrial ecosystems, yet the fundamental relationships between plant diversity and soil microbial diversity remain elusive. Theory predicts predominantly positive associations but tests within single sites have shown variable relationships, and associations between plant and microbial diversity across broad spatial scales remain largely unexplored. We compared the diversity of plant, bacterial, archaeal and fungal communities in one hundred and forty-five 1 m2 plots across 25 temperate grassland sites from four continents. Across sites, the plant alpha diversity patterns were poorly related to those observed for any soil microbial group. However, plant beta diversity (compositional dissimilarity between sites) was significantly correlated with the beta diversity of bacterial and fungal communities, even after controlling for environmental factors. Thus, across a global range of temperate grasslands, plant diversity can predict patterns in the composition of soil microbial communities, but not patterns in alpha diversity.

  4. Building effective working relationships across culturally and ethnically diverse communities.

    Science.gov (United States)

    Hosley, Cheryl A; Gensheimer, Linda; Yang, Mai

    2003-01-01

    Amherst H. Wilder Foundation's Social Adjustment Program for Southeast Asians is implementing two collaborative, best practice, mental health and substance abuse prevention service models in Minnesota. It faced several issues in effectively bridging multiple cultural groups, including building a diverse collaborative team, involving families and youth, reconciling cultural variation in meeting styles, and making best practice models culturally appropriate. Researchers and program staff used multiple strategies to address these challenges and build successful partnerships. Through shared goals, flexibility, and a willingness to explore and address challenges, collaboratives can promote stronger relationships across cultural communities and improve their service delivery systems.

  5. [Community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan salt lake on Qinghai-Tibet Plateau].

    Science.gov (United States)

    Shen, Shuo

    2017-04-04

    I studied the community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan Salt Lake. I isolated and cultured the moderate halophilic bacteria on different selective media. After the 16S rRNA gene sequences was amplified and measured, I constructed the phylogenic tree, analyzed the community structure and calculated the diversity indexes according to the 16S rRNA gene information. A total of 421 moderate halophilic bacteria were isolated from water and mud samples in Qrhan Salt Lake. The 16S rRNA gene information showed that 4 potential novel species belonged to the family Bacillaceae. Eighty-three model strains belonged to 3 phylurms 6 families 16 genus. Among them, Bacillus sp., Oceanobacillus sp. and Halomonas sp. were dominant species. Diversity analysis showed that the diversity of strains isolated from water sample was higher than that from mud sample, but the dominance degree of strains isolated from mud sample was higher than that from water sample. The genetic diversity of moderate halophilic bacteria isolated from Qrhan Salt Lake was abundant. Also, there were dominant and novel species of culturable moderate halophilic bacteria in this lake.

  6. Species Diversity and Functional Prediction of Surface Bacterial Communities on Aging Flue-Cured Tobaccos.

    Science.gov (United States)

    Wang, Fan; Zhao, Hongwei; Xiang, Haiying; Wu, Lijun; Men, Xiao; Qi, Chang; Chen, Guoqiang; Zhang, Haibo; Wang, Yi; Xian, Mo

    2018-06-05

    Microbes on aging flue-cured tobaccos (ATFs) improve the aroma and other qualities desirable in products. Understanding the relevant organisms would picture microbial community diversity, metabolic potential, and their applications. However, limited efforts have been made on characterizing the microbial quality and functional profiling. Herein, we present our investigation of the bacterial diversity and predicted potential genetic capability of the bacteria from two AFTs using 16S rRNA gene sequences and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) software. The results show that dominant bacteria from AFT surfaces were classified into 48 genera, 36 families, and 7 phyla. In addition, Bacillus spp. was found prevalent on both ATFs. Furthermore, PICRUSt predictions of bacterial community functions revealed many attractive metabolic capacities in the AFT microbiota, including several involved in the biosynthesis of flavors and fragrances and the degradation of harmful compounds, such as nicotine and nitrite. These results provide insights into the importance of AFT bacteria in determining product qualities and indicate specific microbial species with predicted enzymatic capabilities for the production of high-efficiency flavors, the degradation of undesirable compounds, and the provision of nicotine and nitrite tolerance which suggest fruitful areas of investigation into the manipulation of AFT microbiota for AFT and other product improvements.

  7. Learning From Critical Collective Spaces: Reflections on the Community-Diversity Dialectic in Safe Spaces

    Directory of Open Access Journals (Sweden)

    Jennifer Wallin-Ruschman

    2016-05-01

    Full Text Available Safe spaces have the potential to become prefigurative groups that aim to create social change. The idea of a safe space as a place separate and sheltered from dominant culture to mobilize for social change has gained traction in a number of academic and practical areas. However, safe spaces have the ability to be both progressive and regressive. To guide our discussion we utilize the concept of community-diversity dialectic to address the tension between these forces within two settings. First we discuss research in an upper level college course rooted in feminist praxis. Then we discuss a faith community’s use of adaptive liturgy with parishioners with intellectual disabilities. Following this discussion, we offer a new term, “critical collective spaces”, to better capture the work done in these spaces. We offer this alternative label to move popular and academic discourse away from debating about how “safe” these spaces are (or are not and toward a more nuanced discussion of the community-diversity dialectic and other tensions within these spaces. Our overall intention is to generate dialogue on the regressive and progressive aspects of these locations and to inform the activism and community building process within prefigurative politics more broadly.

  8. Serving Data to the GLAST Users Community

    International Nuclear Information System (INIS)

    Stephens, Thomas E.

    2007-01-01

    The scientific community will access the public GLAST data through the website of the GLAST Science Support Center (GSSC). For most data products the GSSC website will link to the NASA High Energy Astrophysics Science Archive Research Center's (HEASARC) Browse interface, which will actually serve the data. For example, data from the GLAST Burst Monitor (GBM) from a given burst will be packaged together and accessible through Browse. However, the photon and event data produced by the Large Area Telescope (LAT), GLAST's primary instrument, will be distributed through a custom GSSC interface. These data will be collected over the LAT's large field-of-view, usually while the LAT is scanning the sky, and thus photons from a particular direction cannot be attributed to a single 'observation' in the traditional sense. Users will request all photons detected from a region on the sky over a specified time and energy range. Through its website the GSSC will also provide long and short term science timelines, spacecraft position and attitude histories, exposure maps and other scientific data products. The different data products provided by the GSSC will be described

  9. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity.

    Science.gov (United States)

    Hertzog, Lionel R; Meyer, Sebastian T; Weisser, Wolfgang W; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  10. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity

    Science.gov (United States)

    Hertzog, Lionel R.; Meyer, Sebastian T.; Weisser, Wolfgang W.; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  11. Long-term nickel exposure altered the bacterial community composition but not diversity in two contrasting agricultural soils.

    Science.gov (United States)

    Li, Jing; Hu, Hang-Wei; Ma, Yi-Bing; Wang, Jun-Tao; Liu, Yu-Rong; He, Ji-Zheng

    2015-07-01

    Nickel pollution imposes deleterious effects on soil ecosystem. The responses of soil microorganisms to long-term nickel pollution under field conditions remain largely unknown. Here, we used high-throughput sequencing to elucidate the impacts of long-term nickel pollution on soil bacterial communities in two contrasting agricultural soils. Our results found that the soil microbial biomass carbon consistently decreased along the nickel gradients in both soils. Nickel pollution selectively favored or impeded the prevalence of several dominant bacterial guilds, in particular, Actinobacteria showed tolerance, while Acidobacteria and Planctomycetes displayed sensitivity. Despite the apparent shifts in the bacterial community composition, no clear tendency in the bacterial diversity and abundance was identified along the nickel gradients in either soil. Collectively, we provide evidence that long-term nickel pollution shifted the soil bacterial communities, resulting in the decrease of microbial biomass although the bacterial diversity was not significantly changed.

  12. Diversity of endophytic fungal and bacterial communities in Ilex paraguariensis grown under field conditions.

    Science.gov (United States)

    Pérez, María Laura; Collavino, Mónica Mariana; Sansberro, Pedro Alfonso; Mroginski, Luis Amado; Galdeano, Ernestina

    2016-04-01

    The composition and diversity of the endophytic community associated with yerba mate (Ilex paraguariensis) was investigated using culture-depending methods. Fungi were identified based on their micromorphological characteristics and internal transcribed spacer rDNA sequence analysis; for bacteria 16S rDNA sequence analysis was used. Fungal and bacterial diversity did not show significant differences between organ age. The highest fungal diversity was registered during fall season and the lowest in winter. Bacterial diversity was higher in stems and increased from summer to winter, in contrast with leaves, which decreased. The most frequently isolated fungus was Fusarium, followed by Colletotrichum; they were both present in all the sampling seasons and organ types assayed. Actinobacteria represented 57.5 % of all bacterial isolates. The most dominant bacterial taxa were Curtobacterium and Microbacterium. Other bacteria frequently found were Methylobacterium, Sphingomonas, Herbiconiux and Bacillus. Nitrogen fixation and phosphate solubilization activity, ACC deaminase production and antagonism against plant fungal pathogens were assayed in endophytic bacterial strains. In the case of fungi, strains of Trichoderma, Penicillium and Aspergillus were assayed for antagonism against pathogenic Fusarium sp. All microbial isolates assayed showed at least one growth promoting activity. Strains of Bacillus, Pantoea, Curtobacterium, Methylobacterium, Brevundimonas and Paenibacillus had at least two growth-promoting activities, and Bacillus, Paenibacillus and the three endophytic fungi showed high antagonistic activity against Fusarium sp. In this work we have made a wide study of the culturable endophytic community within yerba mate plants and found that several microbial isolates could be considered as potential inoculants useful for improving yerba mate production.

  13. Relationship between land use pattern and the structure and diversity of soil meso-micro arthropod community.

    Science.gov (United States)

    Zhang, Limin; Zhang, Xueping; Cui, Wei

    2014-05-01

    Soil arthropod communities can provide valuable information regarding the impacts of human disturbances on ecosystem structure. Our study evaluated the structure, composition and diversity of soil meso-micro arthropod communities, in six different vegetation types and assessed the impacts of human activity. A completely randomized design, including 3 replicates from 6 sites (mowing steppe, natural grassland, severe degradation grassland, farmland, artificial shelter forest, and wetland) was used. Soil samples from the depth of 0 to 20 cm were collected during May, July, and September 2007. Soil meso-micro arthropod were separated using the Tullgren funnels method, and were identified and counted. Soil pH value, organic matter, and total nitrogen were measured in topsoil (0-20 cm) from each site. A total of 5,602 soil meso-micro arthropod individuals were collected, representing 4 classes, 14 orders, and 57 families. Most soil arthropods were widely distributed; however, some species appeared to be influenced by environment variables, and might serve as bioindicators of adverse human impacts. Canonical correspondence analysis indicated the soil arthropod distribution in the severely degraded grassland, mowing steppe, farmland, and shelter forest differed from the natural grassland. Arthropod density and diversity were greatest in May, and the forestland community was the most stable. Because of the vital role soil arthropods have in maintaining a healthy ecosystem, mechanisms to maintain their abundance and diversity should be further evaluated.

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

    Science.gov (United States)

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

    2018-04-06

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

  15. What Online User Innovation Communities Can Teach Us about Capturing the Experiences of Patients Living with Chronic Health Conditions. A Scoping Review.

    Directory of Open Access Journals (Sweden)

    Julia Amann

    Full Text Available In order to adapt to societal changes, healthcare systems need to switch from a disease orientation to a patient-centered approach. Virtual patient networks are a promising tool to favor this switch and much can be learned from the open and user innovation literature where the involvement of online user communities in the innovation process is well-documented.The objectives of this study were 1 to describe the use of online communities as a tool to capture and harness innovative ideas of end users or consumers; and 2 to point to the potential value and challenges of these virtual platforms to function as a tool to inform and promote patient-centered care in the context of chronic health conditions.A scoping review was conducted. A total of seven databases were searched for scientific articles published in English between 1995 and 2014. The search strategy was refined through an iterative process.A total of 144 studies were included in the review. Studies were coded inductively according to their research focus to identify groupings of papers. The first set of studies focused on the interplay of factors related to user roles, motivations, and behaviors that shape the innovation process within online communities. Studies of the second set examined the role of firms in online user innovation initiatives, identifying different organizational strategies and challenges. The third set of studies focused on the idea selection process and measures of success with respect to online user innovation initiatives. Finally, the findings from the review are presented in the light of the particularities and challenges discussed in current healthcare research.The present paper highlights the potential of virtual patient communities to inform and promote patient-centered care, describes the key challenges involved in this process, and makes recommendations on how to address them.

  16. What Online User Innovation Communities Can Teach Us about Capturing the Experiences of Patients Living with Chronic Health Conditions. A Scoping Review.

    Science.gov (United States)

    Amann, Julia; Zanini, Claudia; Rubinelli, Sara

    2016-01-01

    In order to adapt to societal changes, healthcare systems need to switch from a disease orientation to a patient-centered approach. Virtual patient networks are a promising tool to favor this switch and much can be learned from the open and user innovation literature where the involvement of online user communities in the innovation process is well-documented. The objectives of this study were 1) to describe the use of online communities as a tool to capture and harness innovative ideas of end users or consumers; and 2) to point to the potential value and challenges of these virtual platforms to function as a tool to inform and promote patient-centered care in the context of chronic health conditions. A scoping review was conducted. A total of seven databases were searched for scientific articles published in English between 1995 and 2014. The search strategy was refined through an iterative process. A total of 144 studies were included in the review. Studies were coded inductively according to their research focus to identify groupings of papers. The first set of studies focused on the interplay of factors related to user roles, motivations, and behaviors that shape the innovation process within online communities. Studies of the second set examined the role of firms in online user innovation initiatives, identifying different organizational strategies and challenges. The third set of studies focused on the idea selection process and measures of success with respect to online user innovation initiatives. Finally, the findings from the review are presented in the light of the particularities and challenges discussed in current healthcare research. The present paper highlights the potential of virtual patient communities to inform and promote patient-centered care, describes the key challenges involved in this process, and makes recommendations on how to address them.

  17. Impact of redox-stratification on the diversity and distribution of bacterial communities in sandy reef sediments in a microcosm

    Institute of Scientific and Technical Information of China (English)

    GAO Zheng; WANG Xin; Angelos K. HANNIDES; Francis J. SANSONE; WANG Guangyi

    2011-01-01

    Relationships between microbial communities and geochemical environments are important in marine microbial ecology and biogeochemistry.Although biogeochemical redox stratification has been well documented in marine sediments,its impact on microbial communities remains largely unknown.In this study,we applied denaturing gradient gel electrophoresis (DGGE) and clone library construction to investigate the diversity and stratification of bacterial communities in redox-stratified sandy reef sediments in a microcosm.A total of 88 Operational Taxonomic Units (OTU) were identified from 16S rRNA clone libraries constructed from sandy reef sediments in a laboratory microcosm.They were members of nine phyla and three candidate divisions,including Proteobacteria (Alpha-,Beta-,Gamma-,Delta-,and Epsilonproteobacteria),Actinobacteria,Acidobacteria,Bacteroidetes,Chloroflexi,Cyanobacteria,Firmicutes,Verrucomicrobia,Spirochaetes,and the candidate divisions WS3,SO31 and AO19.The vast majority of these phylotypes are related to clone sequences from other marine sediments,but OTUs of Epsilonproteobacteria and WS3 are reported for the first time from permeable marine sediments.Several other OTUs are potential new bacterial phylotypes because of their low similarity with reference sequences.Results from the 16S rRNA,gene clone sequence analyses suggested that bacterial communities exhibit clear stratification across large redox gradients in these sediments,with the highest diversity found in the anoxic layer (15-25 mm) and the least diversity in the suboxic layer (3-5 mm).Analysis of the nosZ,and amoA gene libraries also indicated the stratification of denitrifiers and nitrifiers,with their highest diversity being in the anoxic and oxic sediment layers,respectively.These results indicated that redox-stratification can affect the distribution of bacterial communities in sandy reef sediments.

  18. Resource diversity and provenance underpin spatial patterns in functional diversity across native and exotic species.

    Science.gov (United States)

    Méndez, Verónica; Wood, Jamie R; Butler, Simon J

    2018-05-01

    Functional diversity metrics are increasingly used to augment or replace taxonomic diversity metrics to deliver more mechanistic insights into community structure and function. Metrics used to describe landscape structure and characteristics share many of the same limitations as taxonomy-based metrics, particularly their reliance on anthropogenically defined typologies with little consideration of structure, management, or function. However, the development of alternative metrics to describe landscape characteristics has been limited. Here, we extend the functional diversity framework to characterize landscapes based on the diversity of resources available across habitats present. We then examine the influence of resource diversity and provenance on the functional diversities of native and exotic avian communities in New Zealand. Invasive species are increasingly prevalent and considered a global threat to ecosystem function, but the characteristics of and interactions between sympatric native and exotic communities remain unresolved. Understanding their comparative responses to environmental change and the mechanisms underpinning them is of growing importance in predicting community dynamics and changing ecosystem function. We use (i) matrices of resource use (species) and resource availability (habitats) and (ii) occurrence data for 62 native and 25 exotic species and 19 native and 13 exotic habitats in 2015 10 × 10 km quadrats to examine the relationship between native and exotic avian and landscape functional diversity. The numbers of species in, and functional diversities of, native and exotic communities were positively related. Each community displayed evidence of environmental filtering, but it was significantly stronger for exotic species. Less environmental filtering occurred in landscapes providing a more diverse combination of resources, with resource provenance also an influential factor. Landscape functional diversity explained a greater

  19. Plant Community and Nitrogen Deposition as Drivers of Alpha and Beta Diversities of Prokaryotes in Reconstructed Oil Sand Soils and Natural Boreal Forest Soils

    Science.gov (United States)

    Prescott, Cindy E.; Renaut, Sébastien; Terrat, Yves; Grayston, Sue J.

    2017-01-01

    ABSTRACT The Athabasca oil sand deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess whether the soil prokaryotic alpha diversity (α-diversity) and β-diversity in oil sand soils reconstructed 20 to 30 years previously and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal forest soils subject to wildfire disturbance. Prokaryotic α-diversity and β-diversity were assessed using massively parallel sequencing of 16S rRNA genes. The β-diversity, but not the α-diversity, differed between reconstructed and natural soils. Bacteria associated with an oligotrophic lifestyle were more abundant in natural forest soils, whereas bacteria associated with a copiotrophic lifestyle were more abundant in reconstructed soils. Ammonia-oxidizing archaea were most abundant in reconstructed soils planted with grasses. Plant species were the main factor influencing α-diversity in natural and in reconstructed soils. Nitrogen deposition, pH, and plant species were the main factors influencing the β-diversity of the prokaryotic communities in natural and reconstructed soils. The results highlight the importance of nitrogen deposition and aboveground-belowground relationships in shaping soil microbial communities in natural and reconstructed soils. IMPORTANCE Covering over 800 km2, land disturbed by the exploitation of the oil sands in Canada has to be restored. Here, we take advantage of the proximity between these reconstructed ecosystems and the boreal forest surrounding the oil sand mining area to study soil microbial community structure and processes in both natural and nonnatural environments. By identifying key characteristics shaping the structure of soil microbial communities, this study improved our understanding of

  20. Preparing Teachers for Diversity: A Literature Review and Implications from Community-Based Teacher Education

    Science.gov (United States)

    Yuan, Huanshu

    2018-01-01

    This study reviewed current issues in preparing qualified teachers for increasing diverse student populations in the U.S. and in other multicultural and multiethnic countries. Based on the framework of community-based and multicultural teacher education, this literature review paper analyzed issues and problems existed in the current curriculum,…

  1. Reservoir longitudinal gradient promotes ordered losses on diversity and density of Ephemeroptera community

    Directory of Open Access Journals (Sweden)

    S. M. Melo

    2018-02-01

    Full Text Available Abstract Reservoir operations alter, eliminate or restrain the natural hydrologic cycles. Biotic community has become subject to these non-cyclic events, responding by reducing the species diversity. Ephemeroptera species present distinct responses to environmental deterioration such that poses this assemblage between the most useful groups in biomonitoring programs. We hypothesized an alteration in beta diversity at the longitudinal species gradient, which will be influenced mainly by species losses between zones. Changes in temporal beta diversity is also expected, but the main drivers of such alterations will be the species turnover between the sampling period. Ephemeroptera community was monitored in nine sampling points from Itaipu Reservoir, where were installed three sets of substrates composed by a float and 2 wooden substrates. We took biological samples in triplicates monthly, from June-01 to August-02. Our initial hypothesis was partially supported and with significant variations only for spatial approach, between the Reservoir zones. The generated ordering from Non-Metric Dimensional Scale – NMDS - corroborated with spatial analyzes, with the formation of two groups along the gradient zonation of the reservoir. The temporal ordination showed no clear pattern. As expected, the contribution to beta diversity was different for our two approaches, such that the loss of species was more important along the spatial gradient and despite of no significant result, the species replacement was more important among months. The spatial results lead us to infer that differences in limnological characteristics between zones are important for determining differences in Ephemeroptera composition and can reflect the dependency degree of the species in relation to the lentic and sometimes-lotic conditions, mainly in the riverine zone of reservoirs. On the other hand, the absence of a temporal pattern can be result of chaotic variations in the

  2. Response of herbaceous plant community diversity and composition to overstorey harvest within riparian management zones in Northern Hardwoods

    Science.gov (United States)

    Eric K. Zenner; Michelle A. Martin; Brian J. Palik; Jerilynn E. Peck; Charles R. Blinn

    2013-01-01

    Partial timber harvest within riparian management zones (RMZs) may permit active management of riparian forests while protecting stream ecosystems, but impacts on herbaceous communities are poorly understood. We compared herbaceous plant community abundance, diversity and composition in RMZs along small streams in northern Minnesota, USA, among four treatments before...

  3. The right place? Users and professionals' constructions of the place's influence on personal recovery in community mental health services.

    Science.gov (United States)

    Femdal, Ingrid

    2018-01-01

    Current mental health policy emphasizes the importance of community-based service delivery for people with mental health problems to encompass personal recovery. The aim of this study is to explore how users and professionals construct the place's influence on personal recovery in community mental health services. This is a qualitative, interpretive study based on ten individual, semi-structured interviews with users and professionals, respectively. A discourse analysis inspired by the work of Foucault was used to analyze the interviews. The findings show how place can be constructed as a potential for and as a barrier against recovery. Constructions of the aim of the services matter when choosing a place for the services. Further, constructions of user-professional relationships and flexibility are important in the constructions of an appropriate place for the services. The aim of the service, the user-professional relationship, and flexibility in choosing place were essential in the participants' constructions. To find "the right place" for mental health services was constructed as context-sensitive and complex processes of assessment and co-determination. Trial registration The study is approved by the Regional Committee for Medical Research Ethics, Norway (REK-Midt 2011/2057).

  4. Segmenting healthcare terminology users: a strategic approach to large scale evolutionary development.

    Science.gov (United States)

    Price, C; Briggs, K; Brown, P J

    1999-01-01

    Healthcare terminologies have become larger and more complex, aiming to support a diverse range of functions across the whole spectrum of healthcare activity. Prioritization of development, implementation and evaluation can be achieved by regarding the "terminology" as an integrated system of content-based and functional components. Matching these components to target segments within the healthcare community, supports a strategic approach to evolutionary development and provides essential product differentiation to enable terminology providers and systems suppliers to focus on end-user requirements.

  5. Accuracy of microbial community diversity estimated by closed- and open-reference OTUs

    Directory of Open Access Journals (Sweden)

    Robert C. Edgar

    2017-10-01

    Full Text Available Next-generation sequencing of 16S ribosomal RNA is widely used to survey microbial communities. Sequences are typically assigned to Operational Taxonomic Units (OTUs. Closed- and open-reference OTU assignment matches reads to a reference database at 97% identity (closed, then clusters unmatched reads using a de novo method (open. Implementations of these methods in the QIIME package were tested on several mock community datasets with 20 strains using different sequencing technologies and primers. Richness (number of reported OTUs was often greatly exaggerated, with hundreds or thousands of OTUs generated on Illumina datasets. Between-sample diversity was also found to be highly exaggerated in many cases, with weighted Jaccard distances between identical mock samples often close to one, indicating very low similarity. Non-overlapping hyper-variable regions in 70% of species were assigned to different OTUs. On mock communities with Illumina V4 reads, 56% to 88% of predicted genus names were false positives. Biological inferences obtained using these methods are therefore not reliable.

  6. Nitrogen addition, not initial phylogenetic diversity, increases litter decomposition by fungal communities.

    Science.gov (United States)

    Amend, Anthony S; Matulich, Kristin L; Martiny, Jennifer B H

    2015-01-01

    Fungi play a critical role in the degradation of organic matter. Because different combinations of fungi result in different rates of decomposition, determining how climate change will affect microbial composition and function is fundamental to predicting future environments. Fungal response to global change is patterned by genetic relatedness, resulting in communities with comparatively low phylogenetic diversity (PD). This may have important implications for the functional capacity of disturbed communities if lineages sensitive to disturbance also contain unique traits important for litter decomposition. Here we tested the relationship between PD and decomposition rates. Leaf litter fungi were isolated from the field and deployed in microcosms as mock communities along a gradient of initial PD, while species richness was held constant. Replicate communities were subject to nitrogen fertilization comparable to anthropogenic deposition levels. Carbon mineralization rates were measured over the course of 66 days. We found that nitrogen fertilization increased cumulative respiration by 24.8%, and that differences in respiration between fertilized and ambient communities diminished over the course of the experiment. Initial PD failed to predict respiration rates or their change in response to nitrogen fertilization, and there was no correlation between community similarity and respiration rates. Last, we detected no phylogenetic signal in the contributions of individual isolates to respiration rates. Our results suggest that the degree to which PD predicts ecosystem function will depend on environmental context.

  7. Evolving Frameworks for Different Communities of Scientists and End Users

    Science.gov (United States)

    Graves, S. J.; Keiser, K.

    2016-12-01

    Two evolving frameworks for interdisciplinary science will be described in the context of the Common Data Framework for Earth-Observation Data and the importance of standards and protocols. The Event Data Driven Delivery (ED3) Framework, funded by NASA Applied Sciences, provides the delivery of data based on predetermined subscriptions and associated workflows to various communities of end users. ED3's capabilities are used by scientists, as well as policy and resource managers, when event alerts are triggered to respond to their needs. The EarthCube Integration and Testing Environment (ECITE) Assessment Framework for Technology Interoperability and Integration is being developed to facilitate the EarthCube community's assessment of NSF funded technologies addressing Earth science problems. ECITE is addressing the translation of geoscience researchers' use cases into technology use case that apply EarthCube-funded building block technologies (and other existing technologies) for solving science problems. EarthCube criteria for technology assessment include the use of data, metadata and service standards to improve interoperability and integration across program components. The long-range benefit will be the growth of a cyberinfrastructure with technology components that have been shown to work together to solve known science objectives.

  8. Scale Expansion of Community Investigations and Integration of the Effects of Abiotic and Biotic Processes on Maintenance of Species Diversity

    Directory of Open Access Journals (Sweden)

    Zhenhong Wang

    2011-01-01

    Full Text Available Information on the maintenance of diversity patterns from regional to local scales is dispersed among academic fields due to the local focus of community ecology. To better understand these patterns, the study of ecological communities needs to be expanded to larger scales and the various processes affecting them need to be integrated using a suitable quantitative method. We determined a range of communities on a flora-subregional scale in Yunnan province, China (383210.02 km2. A series of species pools were delimited from the regional to plot scales. Plant diversity was evaluated and abiotic and biotic processes identified at each pool level. The species pool effect was calculated using an innovative model, and the contribution of these processes to the maintenance of plant species diversity was determined and integrated: climate had the greatest effect at the flora-subregional scale, with historical and evolutionary processes contributing ∼11%; climate and human disturbance had the greatest effect at the local site pool scale; competition exclusion and stress limitation explained strong filtering at the successional stage pool scale; biotic processes contributed more on the local community scale than on the regional scale. Scale expansion combined with the filtering model approach solves the local problem in community ecology.

  9. Changes in Soil Bacterial Communities and Diversity in ...

    Science.gov (United States)

    Silver-induced selective pressure is becoming increasingly important due to the growing use of silver (Ag) as an antimicrobial agent in biomedical and commercial products. With demonstrated links between environmental resistomes and clinical pathogens, it is important to identify microbial profiles related to silver tolerance/resistance. We investigated the effects of ionic Ag stress on soil bacterial communities and identified resistant/persistant bacterial populations. Silver treatments of 50 - 400 mg Ag kg-1 soil were established in five soils. Chemical lability measurements using diffusive gradients in thin-film devices confirmed that significant (albeit decreasing) labile Ag concentrations were present throughout the 9-month incubation period. Synchrotron X-ray absorption near edge structure spectroscopy demonstrate that this decreasing lability was due to changes in Ag speciation to less soluble forms such as Ag0 and Ag2S. Real-time PCR and Illumina MiSeq screening of 16S rRNA bacterial genes showed β-diversity in response to Ag pressure, and immediate and significant reductions in 16S rRNA gene counts with varying degrees of recovery. These effects were more strongly influenced by exposure time than by Ag dose at these rates. Ag-selected dominant OTUs principally resided in known persister taxa (mainly Gram positive), including metal-tolerant bacteria and slow-growing Mycobacteria. Soil microbial communities have been implicated as sources of an

  10. Differences in Bacterial Diversity and Communities Between Glacial Snow and Glacial Soil on the Chongce Ice Cap, West Kunlun Mountains.

    Science.gov (United States)

    Yang, Guang Li; Hou, Shu Gui; Le Baoge, Ri; Li, Zhi Guo; Xu, Hao; Liu, Ya Ping; Du, Wen Tao; Liu, Yong Qin

    2016-11-04

    A detailed understanding of microbial ecology in different supraglacial habitats is important due to the unprecedented speed of glacier retreat. Differences in bacterial diversity and community structure between glacial snow and glacial soil on the Chongce Ice Cap were assessed using 454 pyrosequencing. Based on rarefaction curves, Chao1, ACE, and Shannon indices, we found that bacterial diversity in glacial snow was lower than that in glacial soil. Principal coordinate analysis (PCoA) and heatmap analysis indicated that there were major differences in bacterial communities between glacial snow and glacial soil. Most bacteria were different between the two habitats; however, there were some common bacteria shared between glacial snow and glacial soil. Some rare or functional bacterial resources were also present in the Chongce Ice Cap. These findings provide a preliminary understanding of the shifts in bacterial diversity and communities from glacial snow to glacial soil after the melting and inflow of glacial snow into glacial soil.

  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. [Responses of functional diversity of aquatic insect community to land use change in middle reach of Qiantang River, East China].

    Science.gov (United States)

    Zhang, Lian-Bo; Liu, Dong-Xiao; Liu, Shuo-Ru; Zhang, Yong; Tong, Xiao-Li; Wang, Bei-Xin

    2013-10-01

    Based on the biological traits such as life history, resistance ability against environmental disturbance, and physiological characteristics of aquatic insects, and by using the fourth-corner statistical method, this paper studied the responses of the functional diversity of aquatic insect community to land use change in the middle reach of Qiantang River, Zhejiang Province of East China. For the test aquatic insect community, some of its biological traits were sensitive to land use change, and altered along human disturbance gradients as expected. With the increasing intensity of human disturbance, the maximal insect body length decreased gradually, the dominant respiration pattern evolved from gill respiration to tegument respiration, and the abundance of burrowers increased significantly. At the same time, the functional diversity measured as Rao's quadratic entropy was significantly higher in reference sites than in disturbed sites (P aquatic community were mainly induced by the land use change caused by human activities, which resulted in the decline of stream water quality and habitat quality and the variations of aquatic insect community composition and biological traits. The aquatic insect biological traits and functional diversity could be the potentially effective indicators in the stream health assessment in the future.

  13. Mechanisms underlying the bioindicator notion: spatial association between individual sexual performance and community diversity.

    Directory of Open Access Journals (Sweden)

    Paola Laiolo

    Full Text Available The bioindicator notion is an appealing concept that has received more support in applied than in basic ecology, mostly due to the difficulty in deriving general ecological rules applicable to all target organisms. However, recognizing the mechanisms that determine the association between a particular species and the well-being of many other species is important for understanding the functioning of ecosystems and the relationship among different biological levels. We examined here the processes at the individual level that cause an association between species performance and biodiversity value, by analyzing attributes that can be studied in a variety of animals with sexual reproduction, namely breeding site selection and condition-dependent sexual signals. Our study model was the Capercaillie, an indicator of forest functioning and diversity, and the associated bird community, used here as a surrogate of broader forest biodiversity. At a regional scale Capercaillie occurrence was not associated with the most diverse forest patches, but at the scale of male spring territories the sexual display grounds (arenas were located in the oldest and less disturbed forest portions, which also hosted the richest local bird communities. Social mechanisms and conspecific cueing likely concurred with habitat-driven processes in determining the long-term persistence of traditional display grounds, which were appealing to many other species because of their structural composition. Characteristics of male vocal display that honestly advertize male quality (low frequencies and rapid song rates were significantly correlated with high diversity values, resulting in a spatial association between individual and community performances. Costly or risky activities such as reproductive or social behaviors, which more than other attributes match gradients in habitat quality, are therefore contributing to functionally connect individuals with ecosystem health.

  14. Online Community Transition Detection

    DEFF Research Database (Denmark)

    Tan, Biying; Zhu, Feida; Qu, Qiang

    2014-01-01

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

  15. Sex Education Targeting African Communities in the United Kingdom: Is It Fit for Purpose?

    Science.gov (United States)

    Schmidt, E.; Olomo, F.; Corcoran, N.

    2012-01-01

    This study addresses the issue of the sexual needs of ethnic minority groups in the UK. Using focus group discussions with health service users and third-sector providers, it explores the perception of sex education by Black African communities living in a culturally diverse area in East London, focusing specifically on participants' understanding…

  16. Barriers and facilitators to using NHS Direct: a qualitative study of 'users' and 'non-users'.

    Science.gov (United States)

    Cook, Erica J; Randhawa, Gurch; Large, Shirley; Guppy, Andy; Chater, Angel M; Ali, Nasreen

    2014-10-25

    NHS Direct, introduced in 1998, has provided 24/7 telephone-based healthcare advice and information to the public in England and Wales. National studies have suggested variation in the uptake of this service amongst the UK's diverse population. This study provides the first exploration of the barriers and facilitators that impact upon the uptake of this service from the perspectives of both 'users' and 'non- users'. Focus groups were held with NHS Direct 'users' (N = 2) from Bedfordshire alongside 'non-users' from Manchester (N = 3) and Mendip, Somerset (N = 4). Each focus group had between five to eight participants. A total of eighty one people aged between 21 and 94 years old (M: 58.90, SD: 22.70) took part in this research. Each focus group discussion lasted approximately 90 minutes and was audiotape-recorded with participants' permission. The recordings were transcribed verbatim. A framework approach was used to analyse the transcripts. The findings from this research uncovered a range of barriers and facilitators that impact upon the uptake of NHS Direct. 'Non-users' were unaware of the range of services that NHS Direct provided. Furthermore, 'non-users' highlighted a preference for face-to face communication, identifying a lack of confidence in discussing healthcare over the telephone. This was particularly evident among older people with cognitive difficulties. The cost to telephone a '0845' number from a mobile was also viewed to be a barrier to access NHS Direct, expressed more often by 'non-users' from deprived communities. NHS Direct 'users' identified that awareness, ease of use and convenience were facilitators which influenced their decision to use the service. An understanding of the barriers and facilitators which impact on the access and uptake of telephone-based healthcare is essential to move patients towards the self-care model. This research has highlighted the need for telephone-based healthcare services to increase public awareness; through

  17. User-Generated Content, YouTube and Participatory Culture on the Web: Music Learning and Teaching in Two Contrasting Online Communities

    Science.gov (United States)

    Waldron, Janice

    2013-01-01

    In this paper, I draw on seminal literature from new media researchers to frame the broader implications that user-generated content (UGC), YouTube, and participatory culture have for music learning and teaching in online communities; to illustrate, I use examples from two contrasting online music communities, the Online Academy of Irish…

  18. Structural diversity effect on hashtag adoption in Twitter

    Science.gov (United States)

    Zhang, Aihua; Zheng, Mingxing; Pang, Bowen

    2018-03-01

    With online social network developing rapidly these years, user' behavior in online social network has attracted a lot of attentions to it. In this paper, we study Twitter user's behavior of hashtag adoption from the perspective of social contagion and focus on "structure diversity" effect on individual's behavior in Twitter. We achieve data through Twitter's API by crawling and build a users' network to carry on empirical research. The Girvan-Newman (G-N) algorithm is used to analyze the structural diversity of user's ego network, and Logistic regression model is adopted to examine the hypothesis. The findings of our empirical study indicate that user' behavior in online social network is indeed influenced by his friends and his decision is significantly affected by the number of groups that these friends belong to, which we call structural diversity.

  19. [Ichthyofauna and its community diversity in volcanic barrier lakes of Northeast China].

    Science.gov (United States)

    Yang, Fu-Yi; Lü, Xian-Guo; Lou, Yan-Jing; Lou, Xiao-Nan; Xue, Bin; Yao, Shu-Chun; Xiao, Hai-Feng

    2012-12-01

    Based on the investigations of fish resources in Jingpo Lake and Wudalianchi Lakes in 2008-2011 and the historical data, this paper analyzed the characteristics of ichthyofauna and its community diversity in volcanic barrier lakes of Northeast China. The ichthyofauna in the volcanic barrier lakes of Northeast China was consisted of 64 native species, belonging to 47 genera, 16 families, and 9 orders, among which, one species was the second class National protected wild animal, four species were Chinese endemic species, and five species were Chinese vulnerable species. In the 64 recorded species, there were 44 species of Cypriniformes order and 37 species of Cyprinidae family dominated, respectively. The ichthyofauna in the volcanic barrier lakes of Northeast China was formed by 7 fauna complexes, among which, the eastern plain fauna complex was dominant, the common species from the South and the North occupied 53.1%, and the northern endemic species took up 46.9%. The Shannon, Fisher-alpha, Pielou, Margalef, and Simpson indices of the ichthyofauna were 2.078, 4.536, 0.575, 3.723, and 0.269, respectively, and the abundance distribution pattern of native species accorded with lognormal model. The Bray-Curtis, Morisita-Horn, Ochiai, Sørensen, and Whittaker indices between the communities of ichthyofauna in the volcanic barrier lakes of Northeast China and the Jingpo Lake were 0.820, 0.992, 0.870, 0.862 and 0.138, respectively, and those between the communities of ichthyofauna in the volcanic barrier lakes and the Wudalianchi Lakes were 0.210, 0.516, 0.838, 0.825, and 0.175, respectively. The ichthyofauna in volcanic barrier lakes of Northeast China was characterized by the mutual infiltration between the South and the North, and the overlap and transition between the Palaeoarctic realm and the Oricetal realm. It was suggested that the ichthyofauna community species diversity in the volcanic barrier lakes of Northeast China was higher, the species structure was more

  20. A tool for computing diversity and consideration on differences between diversity indices

    OpenAIRE

    Palaghianu, Ciprian

    2016-01-01

    Diversity represents a key concept in ecology, and there are various methods of assessing it. The multitude of diversity indices are quite puzzling and sometimes difficult to compute for a large volume of data. This paper promotes a computational tool used to assess the diversity of different entities. The BIODIV software is a user-friendly tool, developed using Microsoft Visual Basic. It is capable to compute several diversity indices such as: Shannon, Simpson, Pielou, Brillouin, Berger-Park...

  1. A trait-based approach to understanding marine communities composition, assembly and diversity

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne

    are characterised by their taxonomic diversity, such as their species richness or the evenness in their abundances. However, there is growing evidence that it is not the taxonomic identity of the species per se that control its presence and abundance in a given environment but its characteristics. Species traits......, we studied the diversity and the processes influencing the composition of demersal fish communities in the Baltic Sea. While species richness was sharply decreasing from the saline Kattegat to the brackish Gdansk Bay, trait richness tended to decrease at a lower rate. We found that the species co...... acting on the species. The strategies’ prevalence exhibited strong geographical patterns which could be explained by spatial variability in annual sea surface temperature, temperature seasonality, depth and fishing intensity. Due to their tight coupling to the environment, notably temperature and fishing...

  2. Application of ion torrent sequencing to the assessment of the effect of alkali ballast water treatment on microbial community diversity.

    Science.gov (United States)

    Fujimoto, Masanori; Moyerbrailean, Gregory A; Noman, Sifat; Gizicki, Jason P; Ram, Michal L; Green, Phyllis A; Ram, Jeffrey L

    2014-01-01

    The impact of NaOH as a ballast water treatment (BWT) on microbial community diversity was assessed using the 16S rRNA gene based Ion Torrent sequencing with its new 400 base chemistry. Ballast water samples from a Great Lakes ship were collected from the intake and discharge of both control and NaOH (pH 12) treated tanks and were analyzed in duplicates. One set of duplicates was treated with the membrane-impermeable DNA cross-linking reagent propidium mono-azide (PMA) prior to PCR amplification to differentiate between live and dead microorganisms. Ion Torrent sequencing generated nearly 580,000 reads for 31 bar-coded samples and revealed alterations of the microbial community structure in ballast water that had been treated with NaOH. Rarefaction analysis of the Ion Torrent sequencing data showed that BWT using NaOH significantly decreased microbial community diversity relative to control discharge (pPCoA) plots and UPGMA tree analysis revealed that NaOH-treated ballast water microbial communities differed from both intake communities and control discharge communities. After NaOH treatment, bacteria from the genus Alishewanella became dominant in the NaOH-treated samples, accounting for microbial community structure between PMA-processed and non-PMA samples occurred in intake water samples, which exhibited a significantly higher amount of PMA-sensitive cyanobacteria/chloroplast 16S rRNA than their corresponding non-PMA total DNA samples. The community assembly obtained using Ion Torrent sequencing was comparable to that obtained from a subset of samples that were also subjected to 454 pyrosequencing. This study showed the efficacy of alkali ballast water treatment in reducing ballast water microbial diversity and demonstrated the application of new Ion Torrent sequencing techniques to microbial community studies.

  3. Towards global patterns in the diversity and community structure of ectomycorrhizal fungi

    DEFF Research Database (Denmark)

    Tedersoo, Leho; Bahram, Mohammad; Toots, Märt

    2012-01-01

    Global species richness patterns of soil micro-organisms remain poorly understood compared to macro-organisms. We use a global analysis to disentangle the global determinants of diversity and community composition for ectomycorrhizal (EcM) fungi—microbial symbionts that play key roles in plant...... nutrition in most temperate and many tropical forest ecosystems. Host plant family has the strongest effect on the phylogenetic community composition of fungi, whereas temperature and precipitation mostly affect EcM fungal richness that peaks in the temperate and boreal forest biomes, contrasting...... with latitudinal patterns of macro-organisms. Tropical ecosystems experience rapid turnover of organic material and have weak soil stratification, suggesting that poor habitat conditions may contribute to the relatively low richness of EcM fungi, and perhaps other soil biota, in most tropical ecosystems. For EcM...

  4. Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

    International Nuclear Information System (INIS)

    Murphy, J.F.; Nagorskaya, L.L.; Smith, J.T.

    2011-01-01

    Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in 137 Cs contamination from 100 to 15500 kBq m -2 and estimated external dose rates ranged from 0.13 to 30.7 μGy h -1 . General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe no. 7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since 90 Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by 90 Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample). - Highlights: → We studied the effect of radiation on macroinvertebrates in Chernobyl affected lakes. → Abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity evaluated. → No relationship between

  5. Phylogenetic and Functional Diversity of Fleshy-Fruited Plants Are Positively Associated with Seedling Diversity in a Tropical Montane Forest

    Directory of Open Access Journals (Sweden)

    Marcia C. Muñoz

    2017-08-01

    Full Text Available Mutualistic interactions between plants and animals can affect both plant and animal communities, and potentially leave imprints on plant demography. Yet, no study has simultaneously tested how trait variation in plant resources shapes the diversity of animal consumers, and how these interactions influence seedling recruitment. Here, we analyzed whether (i phylogenetic diversity and functional diversity of fruiting plants were correlated with the corresponding diversity of frugivorous birds, and (ii whether phylogenetic diversity and functional identity of plant and bird communities influenced the corresponding diversity and identity of seedling communities. We recorded mutualistic interactions between fleshy-fruited plants and frugivorous birds and seedling communities in 10 plots along an elevational gradient in the Colombian Andes. We built a phylogeny for plants/seedlings and birds and measured relevant morphological plant and bird traits that influence plant-bird interactions and seedling recruitment. We found that phylogenetic diversity and functional diversity of frugivorous birds were positively associated with the corresponding diversities of fruiting plants, consistent with a bottom-up effect of plants on birds. Moreover, the phylogenetic diversity of seedlings was related to the phylogenetic diversity of plants, but was unrelated to the phylogenetic diversity of frugivorous birds, suggesting that top-down effects of animals on seedlings were weak. Mean seed mass of seedling communities was positively associated with the mean fruit mass of plants, but was not associated with the mean avian body mass in the frugivore communities. Our study shows that variation in the traits of fleshy-fruited plants was associated with the diversity of frugivorous birds and affected the future trajectory of seedling recruitment, whereas the morphological traits of animal seed dispersers were unrelated to the phylogenetic and functional structure of

  6. The characteristics and experience of community food program users in arctic Canada: a case study from Iqaluit, Nunavut.

    Science.gov (United States)

    Ford, James; Lardeau, Marie-Pierre; Vanderbilt, Will

    2012-06-21

    Community food programs (CFPs), including soup kitchens and food banks, are a recent development in larger settlements in the Canadian Arctic. Our understanding of utilization of these programs is limited as food systems research has not studied the marginalised and transient populations using CFPs, constraining service planning for some of the most vulnerable community members. This paper reports on a baseline study conducted with users of CFPs in Iqaluit, Nunavut, to identify and characterize utilization and document their food security experience. Open ended interviews and a fixed-choice survey on a census (n = 94) were conducted with of users of the food bank, soup kitchen, and friendship centre over a 1 month period, along with key informant interviews. Users of CFPs are more likely to be Inuit, be unemployed, and have not completed high school compared to the general Iqaluit population, while also reporting high dependence on social assistance, low household income, and an absence of hunters in the household. The majority report using CFPs for over a year and on a regular basis. The inability of users to obtain sufficient food must be understood in the context of socio-economic transformations that have affected Inuit society over the last half century as former semi-nomadic hunting groups were resettled into permanent settlements. The resulting livelihood changes profoundly affected how food is produced, processed, distributed, and consumed, and the socio-cultural relationships surrounding such activities. Consequences have included the rising importance of material resources for food access, the weakening of social safety mechanisms through which more vulnerable community members would have traditionally been supported, and acculturative stress. Addressing these broader challenges is essential for food policy, yet CFPs also have an essential role in providing for those who would otherwise have limited food access.

  7. Spatial and Temporal Changes in Fluid Chemistry and Microbial Community Diversity in Subseafloor Habitats at Axial Seamount Following the 1998 Eruption

    Science.gov (United States)

    Opatkiewicz, A. D.; Butterfield, D. A.; Baross, J. A.

    2006-12-01

    The subseafloor associated with hydrothermal vents has the potential to contribute significantly to primary production and biogeochemical cycling in the ocean. However, too little is known about the phylogenetic and physiological diversity of the microbial communities or their in situ activity to assess this potential. There are previous reports that subseafloor environments at active vent sites harbor a high diversity of microorganisms that include different thermal and metabolic groups of Bacteria and Archaea. However, little is known about how these communities change over time (minutes to years), at different vent sites, or in response to perturbations. In an effort to address these issues, the subseafloor microbial community diversity was examined from five diffuse-flow hydrothermal vent sites (distributed geographically over the seamount between three distinguishable vent fields) over the course of six years following the 1998 eruption at Axial Seamount (45° 58'N; 130° 00' W). PCR-based Terminal Restriction Fragment Length Polymorphism (TRFLP) analyses were used to follow changes in the microbial community structure. 16S rRNA gene sequence analysis was used to identify the specific groups of Bacteria and Archaea from the TRFLP analyses. Deep-sea background seawater microorganisms were detected in hydrothermal fluid samples (Bacteria: Alpha and Gamma Proteobacteria, Archaea: Marine Group I Crenarchaeota and Marine Group II Euryarchaeota). The unique subseafloor phylotypes detected included Epsilon, Delta and Beta Proteobacteria, Methanococcales and thermophilic Euryarchaeota. Temperature and key chemical species, which indicate the degree of mixing of hydrothermal fluid with seawater in the subsurface, have been shown previously to be important in affecting the diversity of the microbial communities (Huber et al., 2003). This work substantiates these earlier findings and furthermore presents evidence that additional chemical species, distinguishing the

  8. An architecture for diversity-aware search for medical web content.

    Science.gov (United States)

    Denecke, K

    2012-01-01

    The Web provides a huge source of information, also on medical and health-related issues. In particular the content of medical social media data can be diverse due to the background of an author, the source or the topic. Diversity in this context means that a document covers different aspects of a topic or a topic is described in different ways. In this paper, we introduce an approach that allows to consider the diverse aspects of a search query when providing retrieval results to a user. We introduce a system architecture for a diversity-aware search engine that allows retrieving medical information from the web. The diversity of retrieval results is assessed by calculating diversity measures that rely upon semantic information derived from a mapping to concepts of a medical terminology. Considering these measures, the result set is diversified by ranking more diverse texts higher. The methods and system architecture are implemented in a retrieval engine for medical web content. The diversity measures reflect the diversity of aspects considered in a text and its type of information content. They are used for result presentation, filtering and ranking. In a user evaluation we assess the user satisfaction with an ordering of retrieval results that considers the diversity measures. It is shown through the evaluation that diversity-aware retrieval considering diversity measures in ranking could increase the user satisfaction with retrieval results.

  9. Plant Community and Nitrogen Deposition as Drivers of Alpha and Beta Diversities of Prokaryotes in Reconstructed Oil Sand Soils and Natural Boreal Forest Soils.

    Science.gov (United States)

    Masse, Jacynthe; Prescott, Cindy E; Renaut, Sébastien; Terrat, Yves; Grayston, Sue J

    2017-05-01

    The Athabasca oil sand deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess whether the soil prokaryotic alpha diversity (α-diversity) and β-diversity in oil sand soils reconstructed 20 to 30 years previously and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal forest soils subject to wildfire disturbance. Prokaryotic α-diversity and β-diversity were assessed using massively parallel sequencing of 16S rRNA genes. The β-diversity, but not the α-diversity, differed between reconstructed and natural soils. Bacteria associated with an oligotrophic lifestyle were more abundant in natural forest soils, whereas bacteria associated with a copiotrophic lifestyle were more abundant in reconstructed soils. Ammonia-oxidizing archaea were most abundant in reconstructed soils planted with grasses. Plant species were the main factor influencing α-diversity in natural and in reconstructed soils. Nitrogen deposition, pH, and plant species were the main factors influencing the β-diversity of the prokaryotic communities in natural and reconstructed soils. The results highlight the importance of nitrogen deposition and aboveground-belowground relationships in shaping soil microbial communities in natural and reconstructed soils. IMPORTANCE Covering over 800 km 2 , land disturbed by the exploitation of the oil sands in Canada has to be restored. Here, we take advantage of the proximity between these reconstructed ecosystems and the boreal forest surrounding the oil sand mining area to study soil microbial community structure and processes in both natural and nonnatural environments. By identifying key characteristics shaping the structure of soil microbial communities, this study improved our understanding of how

  10. Mercury alters the bacterial community structure and diversity in soil even at concentrations lower than the guideline values.

    Science.gov (United States)

    Mahbub, Khandaker Rayhan; Subashchandrabose, Suresh Ramraj; Krishnan, Kannan; Naidu, Ravi; Megharaj, Mallavarapu

    2017-03-01

    This study evaluated the effect of inorganic mercury (Hg) on bacterial community and diversity in different soils. Three soils-neutral, alkaline and acidic-were spiked with six different concentrations of Hg ranging from 0 to 200 mg kg -1 and aged for 90 days. At the end of the ageing period, 18 samples from three different soils were investigated for bacterial community structure and soil physicochemical properties. Illumina MiSeq-based 16s ribosomal RNA (rRNA) amplicon sequencing revealed the alteration in the bacterial community between un-spiked control soils and Hg-spiked soils. Among the bacterial groups, Actinobacteria (22.65%) were the most abundant phyla in all samples followed by Proteobacteria (21.95%), Bacteroidetes (4.15%), Firmicutes (2.9%) and Acidobacteria (2.04%). However, the largest group showing increased abundance with higher Hg doses was the unclassified group (45.86%), followed by Proteobacteria. Mercury had a considerable negative impact on key soil functional bacteria such as ammonium oxidizers and nitrifiers. Canonical correspondence analysis (CCA) indicated that among the measured soil properties, Hg had a major influence on bacterial community structure. Furthermore, nonlinear regression analysis confirmed that Hg significantly decreased soil bacterial alpha diversity in lower organic carbon containing neutral and alkaline soils, whereas in acidic soil with higher organic carbon there was no significant correlation. EC 20 values obtained by a nonlinear regression analysis indicated that Hg significantly decreased soil bacterial diversity in concentrations lower than several guideline values.

  11. Metagenomic analysis of bacterial community structure and diversity of lignocellulolytic bacteria in Vietnamese native goat rumen

    NARCIS (Netherlands)

    Do, Huyen Thi; Dao, Khoa Trong; Nguyen, Viet Khanh Hoang; Le Ngoc, Giang; Nguyen, Phuong Thi Mai; Le, Lam Tung; Phung, Nguyet Thu; M. van Straalen, Nico; Roelofs, Dick; Truong, Hai Nam

    2017-01-01

    Objective: In a previous study, analysis of Illumina sequenced metagenomic DNA data of bacteria in Vietnamese goats' rumen showed a high diversity of putative lignocellulolytic genes. In this study, taxonomy speculation of microbial community and lignocellulolytic bacteria population in the rumen

  12. Community Extreme Tonnage User Service (CETUS): A 5000 Ton Open Research Facility in the United States

    Science.gov (United States)

    Danielson, L. R.; Righter, K.; Vander Kaaden, K. E.; Rowland, R. L., II; Draper, D. S.; McCubbin, F. M.

    2017-12-01

    Large sample volume 5000 ton multi-anvil presses have contributed to the exploration of deep Earth and planetary interiors, synthesis of ultra-hard and other novel materials, and serve as a sample complement to pressure and temperature regimes already attainable by diamond anvil cell experiments. However, no such facility exists in the Western Hemisphere. We are establishing an open user facility for the entire research community, with the unique capability of a 5000 ton multi-anvil and deformation press, HERA (High pressure Experimental Research Apparatus), supported by a host of extant co-located experimental and analytical laboratories and research staff. We offer wide range of complementary and/or preparatory experimental options. Any required synthesis of materials or follow up experiments can be carried out controlled atmosphere furnaces, piston cylinders, multi-anvil, or experimental impact apparatus. Additionally, our division houses two machine shops that would facilitate any modification or custom work necessary for development of CETUS, one for general fabrication and one located specifically within our experimental facilities. We also have a general sample preparation laboratory, specifically for experimental samples, that allows users to quickly and easily prepare samples for ebeam analyses and more. Our focus as contract staff is on serving the scientific needs of our users and collaborators. We are seeking community expert input on multiple aspects of this facility, such as experimental assembly design, module modifications, immediate projects, and future innovation initiatives. We've built a cooperative network of 12 (and growing) collaborating institutions, including COMPRES. CETUS is a coordinated effort leveraging HERA with our extant experimental, analytical, and planetary process modelling instrumentation and expertise in order to create a comprehensive model of the origin and evolution of our solar system and beyond. We are looking to engage

  13. Factors Influencing Bacterial Diversity and Community Composition in Municipal Drinking Waters in the Ohio River Basin, USA.

    Directory of Open Access Journals (Sweden)

    Lee F Stanish

    Full Text Available The composition and metabolic activities of microbes in drinking water distribution systems can affect water quality and distribution system integrity. In order to understand regional variations in drinking water microbiology in the upper Ohio River watershed, the chemical and microbiological constituents of 17 municipal distribution systems were assessed. While sporadic variations were observed, the microbial diversity was generally dominated by fewer than 10 taxa, and was driven by the amount of disinfectant residual in the water. Overall, Mycobacterium spp. (Actinobacteria, MLE1-12 (phylum Cyanobacteria, Methylobacterium spp., and sphingomonads were the dominant taxa. Shifts in community composition from Alphaproteobacteria and Betaproteobacteria to Firmicutes and Gammaproteobacteria were associated with higher residual chlorine. Alpha- and beta-diversity were higher in systems with higher chlorine loads, which may reflect changes in the ecological processes structuring the communities under different levels of oxidative stress. These results expand the assessment of microbial diversity in municipal distribution systems and demonstrate the value of considering ecological theory to understand the processes controlling microbial makeup. Such understanding may inform the management of municipal drinking water resources.

  14. Diversity and morphological structure of bacterial communities inhabiting the Diana-Hygieia Thermal Spring (Budapest, Hungary).

    Science.gov (United States)

    Anda, Dóra; Büki, Gabriella; Krett, Gergely; Makk, Judit; Márialigeti, Károly; Erőss, Anita; Mádl-Szőnyi, Judit; Borsodi, Andrea K

    2014-09-01

    The Buda Thermal Karst System is an active hypogenic karst area that offers possibility for the analysis of biogenic cave formation. The aim of the present study was to gain information about morphological structure and genetic diversity of bacterial communities inhabiting the Diana-Hygieia Thermal Spring (DHTS). Using scanning electron microscopy, metal accumulating and unusual reticulated filaments were detected in large numbers in the DHTS biofilm samples. The phyla Actinobacteria, Firmicutes and Proteobacteria were represented by both bacterial strains and molecular clones but phyla Acidobacteria, Chlorobi, Chlorofexi, Gemmatimonadetes, Nitrospirae and Thermotogae only by molecular clones which showed the highest similarity to uncultured clone sequences originating from different environmental sources. The biofilm bacterial community proved to be somewhat more diverse than that of the water sample and the distribution of the dominant bacterial clones was different between biofilm and water samples. The majority of biofilm clones was affiliated with Deltaproteobacteria and Nitrospirae while the largest group of water clones was related to Betaproteobacteria. Considering the metabolic properties of known species related to the strains and molecular clones from DHTS, it can be assumed that these bacterial communities may participate in the local sulphur and iron cycles, and contribute to biogenic cave formation.

  15. “Un-Googling”: Research Technologies, Communities at Risk and the Ethics of User Studies in HCI

    DEFF Research Database (Denmark)

    Shklovski, Irina; Vertesi, Janet

    2012-01-01

    Recent increase in volume of qualitative work on transnational technologies, HCI for development, virtual communities, and collaborative systems across a range of areas has resulted in focus on user communities whose very uniqueness may be of interest to HCI, but whose exposure in a research...... setting presents real threats to those individual’s or community’s livelihoods, work, or civil liberties. As the tools of research dissemination increasingly make scholarly publications more easily accessible to the public and other entities outside the academic community through simple search engines......, scholars must grapple with new challenges to the ethics of exposure. We present a case-study of un-Googling publication of research results and consider potential problems with such an approach to minimizing risk to research participants....

  16. Factors affecting collective action for forest fire management: a comparative study of community forest user groups in central Siwalik, Nepal.

    Science.gov (United States)

    Sapkota, Lok Mani; Shrestha, Rajendra Prasad; Jourdain, Damien; Shivakoti, Ganesh P

    2015-01-01

    The attributes of social ecological systems affect the management of commons. Strengthening and enhancing social capital and the enforcement of rules and sanctions aid in the collective action of communities in forest fire management. Using a set of variables drawn from previous studies on the management of commons, we conducted a study across 20 community forest user groups in Central Siwalik, Nepal, by dividing the groups into two categories based on the type and level of their forest fire management response. Our study shows that the collective action in forest fire management is consistent with the collective actions in other community development activities. However, the effectiveness of collective action is primarily dependent on the complex interaction of various variables. We found that strong social capital, strong enforcement of rules and sanctions, and users' participation in crafting the rules were the major variables that strengthen collective action in forest fire management. Conversely, users' dependency on a daily wage and a lack of transparency were the variables that weaken collective action. In fire-prone forests such as the Siwalik, our results indicate that strengthening social capital and forming and enforcing forest fire management rules are important variables that encourage people to engage in collective action in fire management.

  17. User community vs. producer innovation development efficiency

    DEFF Research Database (Denmark)

    Hienerth, Christoph; von Hippel, Eric; Jensen, Morten Berg

    2014-01-01

    In this paper we report upon a first empirical exploration of the relative efficiency of innovation development by product users vs. product producers. In a study of over 50 years of product innovation in the whitewater kayaking field, we find users in aggregate were approximately 3× more efficie...

  18. Oxygen minimum zones harbour novel viral communities with low diversity.

    Science.gov (United States)

    Cassman, Noriko; Prieto-Davó, Alejandra; Walsh, Kevin; Silva, Genivaldo G Z; Angly, Florent; Akhter, Sajia; Barott, Katie; Busch, Julia; McDole, Tracey; Haggerty, J Matthew; Willner, Dana; Alarcón, Gadiel; Ulloa, Osvaldo; DeLong, Edward F; Dutilh, Bas E; Rohwer, Forest; Dinsdale, Elizabeth A

    2012-11-01

    Oxygen minimum zones (OMZs) are oceanographic features that affect ocean productivity and biodiversity, and contribute to ocean nitrogen loss and greenhouse gas emissions. Here we describe the viral communities associated with the Eastern Tropical South Pacific (ETSP) OMZ off Iquique, Chile for the first time through abundance estimates and viral metagenomic analysis. The viral-to-microbial ratio (VMR) in the ETSP OMZ fluctuated in the oxycline and declined in the anoxic core to below one on several occasions. The number of viral genotypes (unique genomes as defined by sequence assembly) ranged from 2040 at the surface to 98 in the oxycline, which is the lowest viral diversity recorded to date in the ocean. Within the ETSP OMZ viromes, only 4.95% of genotypes were shared between surface and anoxic core viromes using reciprocal BLASTn sequence comparison. ETSP virome comparison with surface marine viromes (Sargasso Sea, Gulf of Mexico, Kingman Reef, Chesapeake Bay) revealed a dissimilarity of ETSP OMZ viruses to those from other oceanic regions. From the 1.4 million non-redundant DNA sequences sampled within the altered oxygen conditions of the ETSP OMZ, more than 97.8% were novel. Of the average 3.2% of sequences that showed similarity to the SEED non-redundant database, phage sequences dominated the surface viromes, eukaryotic virus sequences dominated the oxycline viromes, and phage sequences dominated the anoxic core viromes. The viral community of the ETSP OMZ was characterized by fluctuations in abundance, taxa and diversity across the oxygen gradient. The ecological significance of these changes was difficult to predict; however, it appears that the reduction in oxygen coincides with an increased shedding of eukaryotic viruses in the oxycline, and a shift to unique viral genotypes in the anoxic core. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  19. How user diversity and country of origin impact the readiness to adopt E-health technologies: an intercultural comparison.

    Science.gov (United States)

    Wilkowsk, Wiktoria; Ziefle, Martina; Alagöz, Firat

    2012-01-01

    In recent years, due to the demographical change and the resulting overload of healthcare systems, there has been an increasing interest focusing on the global proliferation of assistive medical technologies (=E-health) in home environments. The present study examines how users' diversity influences the readiness to adopt novel medical technologies, comparing users' attitudes in terms of perceived advantages and disadvantages in three technically and culturally different countries: Germany, Poland and Turkey. This investigation also intended to verify if acceptance of information and communication technologies is associated with the sensitive acceptance of E-health. Results revealed overall a considerably higher motivation to use medical technology compared to perceived barriers, with Polish users more willing to use E-health, higher than German or Turkish ones. Older participants showed a highly positive attitude, comparable to young and middle-aged respondents' receptiveness, differing from the latter in terms of greater appreciation of the advantage of higher independency when being supported by medical technology. With respect to gender, woman showed higher motivation to use E-health technology than men, although utilization barriers were not gendered. Following these results, an unconditional transfer of acceptance from information and communication to medical technology is not justified.

  20. Broad host range plasmids can invade an unexpectedly diverse fraction of a soil bacterial community

    DEFF Research Database (Denmark)

    Klümper, Uli; Riber, Leise; Dechesne, Arnaud

    2014-01-01

    and Actinobacteria suggests that inter-Gram plasmid transfer of IncP-1 and IncPromA-type plasmids is a frequent phenomenon. While the plasmid receiving fractions of the community were both plasmid- and donor- dependent, we identified a core super-permissive fraction that could take up different plasmids from diverse...

  1. Dissolved Organic Carbon Influences Microbial Community Composition and Diversity in Managed Aquifer Recharge Systems

    KAUST Repository

    Li, D.; Sharp, J. O.; Saikaly, Pascal; Ali, Shahjahan; Alidina, M.; Alarawi, M. S.; Keller, S.; Hoppe-Jones, C.; Drewes, J. E.

    2012-01-01

    This study explores microbial community structure in managed aquifer recharge (MAR) systems across both laboratory and field scales. Two field sites, the Taif River (Taif, Saudi Arabia) and South Platte River (Colorado), were selected as geographically distinct MAR systems. Samples derived from unsaturated riverbed, saturated-shallow-infiltration (depth, 1 to 2 cm), and intermediate-infiltration (depth, 10 to 50 cm) zones were collected. Complementary laboratory-scale sediment columns representing low (0.6 mg/liter) and moderate (5 mg/liter) dissolved organic carbon (DOC) concentrations were used to further query the influence of DOC and depth on microbial assemblages. Microbial density was positively correlated with the DOC concentration, while diversity was negatively correlated at both the laboratory and field scales. Microbial communities derived from analogous sampling zones in each river were not phylogenetically significantly different on phylum, class, genus, and species levels, as determined by 16S rRNA gene pyrosequencing, suggesting that geography and season exerted less sway than aqueous geochemical properties. When field-scale communities derived from the Taif and South Platte River sediments were grouped together, principal coordinate analysis revealed distinct clusters with regard to the three sample zones (unsaturated, shallow, and intermediate saturated) and, further, with respect to DOC concentration. An analogous trend as a function of depth and corresponding DOC loss was observed in column studies. Canonical correspondence analysis suggests that microbial classes Betaproteobacteria and Gammaproteobacteria are positively correlated with DOC concentration. Our combined analyses at both the laboratory and field scales suggest that DOC may exert a strong influence on microbial community composition and diversity in MAR saturated zones.

  2. Dissolved Organic Carbon Influences Microbial Community Composition and Diversity in Managed Aquifer Recharge Systems

    KAUST Repository

    Li, D.

    2012-07-13

    This study explores microbial community structure in managed aquifer recharge (MAR) systems across both laboratory and field scales. Two field sites, the Taif River (Taif, Saudi Arabia) and South Platte River (Colorado), were selected as geographically distinct MAR systems. Samples derived from unsaturated riverbed, saturated-shallow-infiltration (depth, 1 to 2 cm), and intermediate-infiltration (depth, 10 to 50 cm) zones were collected. Complementary laboratory-scale sediment columns representing low (0.6 mg/liter) and moderate (5 mg/liter) dissolved organic carbon (DOC) concentrations were used to further query the influence of DOC and depth on microbial assemblages. Microbial density was positively correlated with the DOC concentration, while diversity was negatively correlated at both the laboratory and field scales. Microbial communities derived from analogous sampling zones in each river were not phylogenetically significantly different on phylum, class, genus, and species levels, as determined by 16S rRNA gene pyrosequencing, suggesting that geography and season exerted less sway than aqueous geochemical properties. When field-scale communities derived from the Taif and South Platte River sediments were grouped together, principal coordinate analysis revealed distinct clusters with regard to the three sample zones (unsaturated, shallow, and intermediate saturated) and, further, with respect to DOC concentration. An analogous trend as a function of depth and corresponding DOC loss was observed in column studies. Canonical correspondence analysis suggests that microbial classes Betaproteobacteria and Gammaproteobacteria are positively correlated with DOC concentration. Our combined analyses at both the laboratory and field scales suggest that DOC may exert a strong influence on microbial community composition and diversity in MAR saturated zones.

  3. Dissolved organic carbon influences microbial community composition and diversity in managed aquifer recharge systems.

    Science.gov (United States)

    Li, Dong; Sharp, Jonathan O; Saikaly, Pascal E; Ali, Shahjahan; Alidina, Mazahirali; Alarawi, Mohammed S; Keller, Stephanie; Hoppe-Jones, Christiane; Drewes, Jörg E

    2012-10-01

    This study explores microbial community structure in managed aquifer recharge (MAR) systems across both laboratory and field scales. Two field sites, the Taif River (Taif, Saudi Arabia) and South Platte River (Colorado), were selected as geographically distinct MAR systems. Samples derived from unsaturated riverbed, saturated-shallow-infiltration (depth, 1 to 2 cm), and intermediate-infiltration (depth, 10 to 50 cm) zones were collected. Complementary laboratory-scale sediment columns representing low (0.6 mg/liter) and moderate (5 mg/liter) dissolved organic carbon (DOC) concentrations were used to further query the influence of DOC and depth on microbial assemblages. Microbial density was positively correlated with the DOC concentration, while diversity was negatively correlated at both the laboratory and field scales. Microbial communities derived from analogous sampling zones in each river were not phylogenetically significantly different on phylum, class, genus, and species levels, as determined by 16S rRNA gene pyrosequencing, suggesting that geography and season exerted less sway than aqueous geochemical properties. When field-scale communities derived from the Taif and South Platte River sediments were grouped together, principal coordinate analysis revealed distinct clusters with regard to the three sample zones (unsaturated, shallow, and intermediate saturated) and, further, with respect to DOC concentration. An analogous trend as a function of depth and corresponding DOC loss was observed in column studies. Canonical correspondence analysis suggests that microbial classes Betaproteobacteria and Gammaproteobacteria are positively correlated with DOC concentration. Our combined analyses at both the laboratory and field scales suggest that DOC may exert a strong influence on microbial community composition and diversity in MAR saturated zones.

  4. Digital Library Services: Perceptions and Expectations of User Communities and Librarians in a New Zealand Academic Library.

    Science.gov (United States)

    Xia, Wei

    2003-01-01

    Provides an overview of research conducted at Victoria University of Wellington regarding differing perceptions and expectations of user communities and librarians related to the usability of digital services. Considers access to services, currency of information on the Web site, the online public access catalog, databases, electronic journals,…

  5. Shifts in phylogenetic diversity of archaeal communities in mangrove sediments at different sites and depths in southeastern Brazil.

    Science.gov (United States)

    Mendes, Lucas William; Taketani, Rodrigo Gouvêa; Navarrete, Acácio Aparecido; Tsai, Siu Mui

    2012-06-01

    This study focused on the structure and composition of archaeal communities in sediments of tropical mangroves in order to obtain sufficient insight into two Brazilian sites from different locations (one pristine and another located in an urban area) and at different depth levels from the surface. Terminal restriction fragment length polymorphism (T-RFLP) of PCR-amplified 16S rRNA gene fragments was used to scan the archaeal community structure, and 16S rRNA gene clone libraries were used to determine the community composition. Redundancy analysis of T-RFLP patterns revealed differences in archaeal community structure according to location, depth and soil attributes. Parameters such as pH, organic matter, potassium and magnesium presented significant correlation with general community structure. Furthermore, phylogenetic analysis revealed a community composition distributed differently according to depth where, in shallow samples, 74.3% of sequences were affiliated with Euryarchaeota and 25.7% were shared between Crenarchaeota and Thaumarchaeota, while for the deeper samples, 24.3% of the sequences were affiliated with Euryarchaeota and 75.7% with Crenarchaeota and Thaumarchaeota. Archaeal diversity measurements based on 16S rRNA gene clone libraries decreased with increasing depth and there was a greater difference between depths (25% of sequences shared). Taken together, our findings indicate that mangrove ecosystems support a diverse archaeal community; it might possibly be involved in nutrient cycles and are affected by sediment properties, depth and distinct locations. Copyright © 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  6. Diversity and dynamics of the DNA- and cDNA-derived compost fungal communities throughout the commercial cultivation process for Agaricus bisporus.

    Science.gov (United States)

    McGee, C F; Byrne, H; Irvine, A; Wilson, J

    2017-01-01

    Commercial cultivation of the button mushroom Agaricus bisporus is performed through the inoculation of a semipasteurized composted material. Pasteurization of the compost material prior to inoculation results in a substrate with a fungal community that becomes dominated by A. bisporus. However, little is known about the composition and activity in the wider fungal community beyond the presence of A. bisporus in compost throughout the mushroom cropping process. In this study, the fungal cropping compost community was characterized by sequencing nuc rDNA ITS1-5.8S-ITS2 amplified from extractable DNA and RNA. The fungal community generated from DNA extracts identified a diverse community containing 211 unique species, although only 51 were identified from cDNA. Agaricus bisporus was found to dominate in the DNA-derived fungal community for the duration of the cropping process. However, analysis of cDNA extracts found A. bisporus to dominate only up to the first crop flush, after which activity decreased sharply and a much broader fungal community became active. This study has highlighted the diverse fungal community that is present in mushroom compost during cropping.

  7. Impact of fishing on size composition and diversity of demersal fish communities

    DEFF Research Database (Denmark)

    Bianchi, G.; Gislason, Henrik; Graham, K.

    2000-01-01

    . but particularly in high-latitude regions, we observe a decreasing trend in the slope, reflecting changes in size composition toward a relative decline in larger fish. The results from tropical regions are less conclusive, partly owing to the difficulty in obtaining consistent data series, but probably also......By analysing data sets from different world regions we add evidence to documented changes in demersal fish community structure that may be related to fishing. Changes are analysed by community properties that might be expected to capture relevant overall changes - size spectra slopes and intercepts...... because the generally higher growth rates of the constituent species make the slope less sensitive to changes in fishing. No evidence was found of any decline in species richness, while changes in diversity (richness and evenness) were caused either by changes in patterns of dominance or by changes...

  8. A phylogenetic perspective on species diversity, β-diversity and biogeography for the microbial world.

    Science.gov (United States)

    Barberán, Albert; Casamayor, Emilio O

    2014-12-01

    There is an increasing interest to combine phylogenetic data with distributional and ecological records to assess how natural communities arrange under an evolutionary perspective. In the microbial world, there is also a need to go beyond the problematic species definition to deeply explore ecological patterns using genetic data. We explored links between evolution/phylogeny and community ecology using bacterial 16S rRNA gene information from a high-altitude lakes district data set. We described phylogenetic community composition, spatial distribution, and β-diversity and biogeographical patterns applying evolutionary relatedness without relying on any particular operational taxonomic unit definition. High-altitude lakes districts usually contain a large mosaic of highly diverse small water bodies and conform a fine biogeographical model of spatially close but environmentally heterogeneous ecosystems. We sampled 18 lakes in the Pyrenees with a selection criteria focused on capturing the maximum environmental variation within the smallest geographical area. The results showed highly diverse communities nonrandomly distributed with phylogenetic β-diversity patterns mainly shaped by the environment and not by the spatial distance. Community similarity based on both bacterial taxonomic composition and phylogenetic β-diversity shared similar patterns and was primarily structured by similar environmental drivers. We observed a positive relationship between lake area and phylogenetic diversity with a slope consistent with highly dispersive planktonic organisms. The phylogenetic approach incorporated patterns of common ancestry into bacterial community analysis and emerged as a very convenient analytical tool for direct inter- and intrabiome biodiversity comparisons and sorting out microbial habitats with potential application in conservation studies. © 2014 John Wiley & Sons Ltd.

  9. Routing Questions to the Right Users in Online Communities

    DEFF Research Database (Denmark)

    Zhou, Yanhong; Cong, Gao; Cui, Bin

    2009-01-01

    Online forums contain huge amounts of valuable user-generated content. In current forum systems, users have to passively wait for other use